title: Atkinson cycle

text: In the late 20th century, the term "Atkinson cycle" began to be used to describe a modified Otto-cycle engine—in which the intake valve is held open longer than normal, allowing a reverse flow of intake air into the intake manifold. This "simulated" Atkinson cycle is most notably used in the Toyota 1NZ-FXE engine from the early Prius and the Toyota Dynamic Force engine used by many vehicles.


title: Atkinson cycle

text: The effective compression ratio is reduced—for the time the air is escaping the cylinder freely rather than being compressed—but the "expansion" ratio is unchanged (i.e., the compression ratio is smaller than the expansion ratio). The goal of the modern Atkinson cycle is to make the pressure in the combustion chamber at the end of the power stroke equal to atmospheric pressure. When this occurs, all available energy has been obtained from the combustion process. For any given portion of air, the greater expansion ratio converts more energy from heat to useful mechanical energy—meaning the engine is more efficient.


title: Atkinson cycle

text: The disadvantage of the four-stroke Atkinson-cycle engine versus the more common Otto-cycle engine is reduced power density. Due to a smaller portion of the compression stroke being devoted to compressing the intake air, an Atkinson-cycle engine does not take in as much air as would a similarly designed and sized Otto-cycle engine. Four-stroke engines of this type that use the same type of intake valve motion but using forced induction to make up for the loss of power density are known as Miller-cycle engines.


title: Atkinson cycle

text: The Atkinson cycle can be used in a rotary engine. In this configuration, an increase in both power and efficiency can be achieved when compared to the Otto cycle. This type of engine retains the one power phase per revolution, together with the different compression and expansion volumes of the original Atkinson cycle.


title: Atkinson cycle

text: Exhaust gases are expelled from the engine by compressed-air scavenging. This modification of the Atkinson cycle allows the use of alternative fuels such as diesel and hydrogen.


title: Atkinson cycle

text: Disadvantages of this design include the requirement that rotor tips seal very tightly on the outer housing wall and the mechanical losses suffered through friction between rapidly oscillating parts of irregular shape. See external links below for more information.


title: Atkinson cycle

text: The Sachs KC-27 Wankel engine in the Hercules W-2000 motorcycle used the Atkinson cycle. A depression capsule opens a secondary path for the incoming charge.


title: Atkinson cycle

text: While a modified Otto-cycle piston engine using the Atkinson cycle provides good fuel efficiency, it is at the expense of a lower power-per-displacement as compared to a traditional four-stroke engine. If demand for more power is intermittent, the power of the engine can be supplemented by an electric motor during times when more power is needed. This forms the basis of an Atkinson cycle-based hybrid electric drivetrain. These electric motors can be used independently of, or in combination with, the Atkinson-cycle engine, to provide the most efficient means of producing the desired power. This drive-train first entered production in late 1997 in the first-generation Toyota Prius.


title: Atkinson cycle

text: The 1887 patent (US 367496) describes the mechanical linkages necessary to obtain all four strokes of the four-stroke cycle for a gas engine within one revolution of the crankshaft. There is also a reference to an 1886 Atkinson patent (US 336505), which describes an opposed-piston gas engine. The British patent for the "Utilite'" is from 1892 (#2492).


title: Chevrolet Camaro (second generation)

text: The second-generation Chevrolet Camaro is an American pony car that was produced by Chevrolet from 1970 through the 1981 model years. It was introduced in the spring of 1970. Build information for model 123-12487 was released to the assembly plants in February of that same year. It was longer, lower, and wider than the first generation Camaro. A convertible, which was available for the first generation, was unavailable for the second. GM engineers have said the second generation is much more of "A Driver's Car" than its predecessor.


title: Chevrolet Camaro (second generation)

text: Dubbed "Super Hugger", the second-generation Camaro was an all-new car with its basic mechanical layout familiar and engineered much like its predecessor with a unibody structure utilizing a front subframe, A-arm and coil spring front suspension, and rear leaf springs.


title: Chevrolet Camaro (second generation)

text: The chassis and suspension of the second generation were refined in both performance and comfort; base models offered significant advances in sound-proofing, ride isolation, and road-holding. Extensive experience Chevrolet engineers had gained racing the first-generation led directly to advances in second-generation Camaro steering, braking, and balance. High-performance configurations were initially available, but the marketplace changed as 1970s progressed with fuel crisis, higher insurance rates, and tightening emissions regulations. Major styling changes were made in 1974 and 1978; 1981 was the final model year for the second-generation Camaro.


title: Chevrolet Camaro (second generation)

text: Most of the engine and drivetrain components were carried over from 1969, with the exception of the six-cylinder — the base engine was now the six, rated at . The 1970 Camaro SS 396 had the L78 rated at . Starting in 1970, the big block V8s (nominally ) actually displaced , yet Chevrolet chose to retain the 396 badges, equipped with a single 4-barrel Holley carburetor that produced at 5,600 rpm and at 3,600 rpm of torque. Two engines (the LS6 and LS7) were listed on early specification sheets and in some sales brochures but never made it into production. Besides the base model, buyers could select the Rally Sport option with a distinctive nose and bumper, a Super Sport package, and the Z-28 Special Performance Package (priced at US$572.95) featuring a new high-performance LT-1 of torque V8. The LT-1, an engine built from the ground up using premium parts and components, was a much better performer overall than the previous V8s used in 1967-69 Z-28s; greater torque and less-radical cam, coupled with the 780 cfm Holley four-barrel, permitted the Z-28 to be available with the 3-speed Turbo Hydramatic 400 automatic transmission as an option to the four-speed manual for the first time. The LT-1 engine in the 1970 Camaro Z-28 came from the Corvette.


title: Chevrolet Camaro (second generation)

text: The new body style featured a fastback roofline and ventless full-door glass with no rear side quarter windows. Doors were wider to permit easier access to the rear seat, and new pull-up handles replaced the old handles, for which the lower button had to be pushed in to open the door. The roof was a new double-shell unit for improved rollover protection and noise reduction. The base model featured a separate bumper/grille design with parking lights under the bumper, while the Rally Sport option included a distinctive grille surrounded by a flexible Endura material along with round parking lights beside the headlights and bumperettes surrounding on both sides of the grille. The rear was highlighted by four round taillights similar to the Corvette. A convertible was not offered, making this the only Camaro generation not to offer one.


title: Chevrolet Camaro (second generation)

text: The 1970 was the first Camaro offered with a rear stabilizer bar. The four-wheel disc brake option (RPO JL8 of 1969) was dropped.


title: Chevrolet Camaro (second generation)

text: Inside, a new curved instrument panel featured several round dials for gauges and other switches directly in front of the driver while the lower section included the heating/air conditioning controls to the driver's left and radio, cigarette lighter and ashtray in the center and glovebox door on the right. New Strato bucket seats, unique to 1970 models, featured squared-off seatbacks and adjustable headrests, and the rear seating consisted of two bucket cushions and a bench seat back due to the higher transmission tunnel. The optional center console, with standard Hurst shifter, was now integrated into the lower dashboard with small storage area or optional stereo tape player. The standard interior featured all-vinyl upholstery and a matte black dashboard finish, while an optional custom interior came with upgraded cloth or vinyl upholstery and woodgrain trim on dash and console.


title: Chevrolet Camaro (second generation)

text: The 1970 model was introduced to the assembly plants in February 1970, halfway through the model year. This caused some people to refer to it as a "1970½." model; all were 1970 models. The 1970 model year vehicles are generally regarded as the most desirable of the early second-generation Camaros, since the performance of following years was reduced by the automobile emissions control systems of the period and later the addition of heavy federally mandated bumpers.


title: Chevrolet Camaro (second generation)

text: The 1971 Camaro received only minor appearance changes from its 1970 counterpart. Inside, new high-back Strato bucket seats with built-in headrests replaced the 1970-only low-back seats with adjustable headrests. The biggest changes came under the hood, due to a GM-corporate mandate that all engines be designed to run on lower-octane regular-leaded, low-lead, or unleaded gasoline, necessitating reductions in compression ratios and horsepower ratings. The straight-6, V8, and two-barrel V8 were virtually unchanged, as they were low-compression regular-fuel engines in 1970 and previous years.


title: Chevrolet Camaro (second generation)

text: The LT-1 350 V8 used in the Z/28 dropped from 360 hp SAE gross to SAE gross due to a compression ratio decrease from 11.0:1 to 10.3:1. The 350 c.i. engine in the 1971 Camaro Z28 produced SAE net. The 396 (402 c.i.) V8 dropped from 350 to SAE gross due to compression ratio drop from 10.25:1 to 8.5:1. The 402 c.i. engine in the 1971 Camaro SS 396 produced SAE net.


title: Chevrolet Camaro (second generation)

text: Production and sales dropped due to a 67-day corporate-wide strike at GM that coincided with the introduction of the 1971 models in late September 1970, along with a continued declining interest in the ponycar market fueled by skyrocketing insurance rates for high-performance cars. Rumors of the possible cancellation of the Camaro after 1972 began to surface and were nearly confirmed a year later when another worker's strike hit the assembly plant at Norwood, Ohio, which was the only plant building Camaros and Firebirds.


title: Chevrolet Camaro (second generation)

text: The 1972 Camaro suffered two major setbacks. The UAW strike at a GM assembly plant in Norwood disrupted production for 174 days, and 1,100 incomplete Camaros had to be scrapped because they could not meet 1973 federal bumper safety standards. Some at GM seriously considered dropping the Camaro and Firebird altogether, particularly while the corporation was under pressure to adapt its vast number of makes and models to difficult new regulations for emissions, safety, and fuel economy. Others pointed out the fiercely loyal followings the cars enjoyed and were convinced the models remained viable. The latter group eventually convinced those in favor of dropping the F-cars to reconsider, and Chevrolet would go on to produce 68,656 Camaros in 1972. Only 970 SS 396s were produced in 1972, and this was the last year for the SS 396 and SS 350 models, as well as the last year the Camaro was offered with a Big Block from the factory. This year the badges changed from "Z/28" to "Z28". Horsepower ratings continued to drop, not only due to lower compression and tighter emissions controls but, beginning with the 1972 model year, a switch from gross (on dynamometer) to net ratings based on an engine in an actual vehicle with all accessories installed. With that, the 350 ci LT1 dropped from 330 gross horsepower in 1971 to 255 net horsepower for 1972 and the big-block 396/402 was now rated at 240 net horsepower compared to 300 gross horses in 1971.


title: Chevrolet Camaro (second generation)

text: The 1973 model year incorporated standard impact-absorbing front bumper system to meet new no-damage standards in NHTSA legislation. The Rally Sport option, with its chrome bumperettes on either side of an impact absorbing urethane grill surround, continued for one more year due to creative bracing behind the front sheetmetal.


title: Chevrolet Camaro (second generation)

text: A new Type LT model was offered in 1973, with a quieter and better-appointed interior, full instrumentation, Rally-style wheels, variable-ratio steering, sport mirrors, and hidden windshield wipers, among other upgrades. The Super Sport package was dropped, and the big block V8 was no longer available. Power was down due to new emissions standards, with the top-rated V8 producing in the Z28. The engine was switched from solid-lifters to hydraulic tappets. Air conditioning became available as an option with this engine. The Z28 option could be ordered on both the sport coupe and LT models. When the Z28 and Type LT options were combined, the usual Z28 badges, stripes, and graphics were deleted.


title: Chevrolet Camaro (second generation)

text: Other changes included a new console-mounted shifter for automatic transmissions similar to the shifter used in Pontiac Firebirds replacing the Buick-like horseshoe shifter of previous Camaros, and the reintroduction of power windows to the option list for the first time since 1969, with the switches mounted in the console.


title: Chevrolet Camaro (second generation)

text: Recovering from the strike, Camaro sales increased to 96,751 units during a record sales year industry-wide.


title: Chevrolet Camaro (second generation)

text: The 1974 Camaro grew seven inches (178 mm) longer, thanks to new aluminum bumpers required to meet federal standards and a forward-sloping grille. Round taillights were replaced with a rectangular wraparound design. It was the last year to have a flat rear window, with thick roof pillars. All later years had slimmer roof pillars and a wraparound rear window for better visibility. This was the last year of the RPO Z28, which shared the same drive train and engine as in the previous year (1973), based on the Corvette L82 special high-performance engine (the Z28 would re-emerge in 1977 as its own model and no longer a RPO).


title: Chevrolet Camaro (second generation)

text: Camaro sales increased to over 150,000 units, of which 13,802 were Z28s (the highest 2nd-generation Z28 production to this time) despite the energy crisis fueled by the Arab Oil Embargo. Two ponycar competitors were repositioned in the marketplace this year. Ford downsized the Mustang to an all new 1974 Ford Mustang II subcompact based on the Pinto that was designed for an era of high gas prices and fuel shortages resulting in 385,993 units produced for the model year. Mercury upsized the Cougar to an intermediate-sized personal luxury car to compete with the Chevrolet Monte Carlo and Pontiac Grand Prix. Other changes included Chrysler Corporation discontinuing the Plymouth Barracuda and Dodge Challenger during the course of the 1974 model year. Likewise, 1974 was the final year of the AMC Javelin, but a sporty AMX model would be reintroduced in 1978.


title: Chevrolet Camaro (second generation)

text: For 1975, a catalytic converter was added to the exhaust system of all US-market GM passenger cars, including the Camaro. The "Air Injection Reactor" secondary air injection system was still present. The catalytic emission control system was more efficient at reducing emissions than the previous non-catalytic system, and allowed engines to be retuned for improved drivability and fuel economy. The catalytic converter and GM High Energy electronic ignition were advertised among the components of "Chevrolet's new Efficiency System" which was promoted to offer other benefits to owners of 1975 models versus comparable 1974 models that included extended maintenance intervals from 6,000 to for oil/filter changes and spark plugs that lasted up to compared to on 1974 models.


title: Chevrolet Camaro (second generation)

text: The Z28 option was discontinued for 1975 despite an increase in sales to over 13,000 units in 1974. Optional engines continued to reflect the impact of emissions. Two 350 cid (5.7 L) V8s produced 145 hp (108 kW) and 155 hp (116 kW) (Horsepower losses can seem a bit exaggerated compared to earlier cars, however, their power ratings were now "net" as opposed to the prior "gross" ratings. SAE net power ratings (used since 1972) were taken from the engine crankshaft as before, but now all accessories had to be attached and operating, and all emissions equipment and a full production exhaust system had to be in place. These power-robbing additions — along with stringent new emissions laws and the equipment they required — were instrumental in creating the vastly smaller power figures found in subsequent cars. The manufacturers themselves also sometimes intentionally underrated engines for a variety of motives, notably avoiding provoking the insurance companies and federal regulators into enacting undesirable policies, but also sometimes to prevent lower priced models from stacking up too well on paper against their own more profitable high-end products.


title: Chevrolet Camaro (second generation)

text: A new wraparound rear window was introduced for 1975 and the Camaro emblem moved from the center of the grille to above the grillework and the "Camaro" nameplate was deleted from the rear decklid. Also new block letter "Camaro" nameplates replaced the previous scripts on the front fenders. Interiors were revised slightly with new seat trim patterns and bird's-eye maple trim replacing the Meridian grained walnut on the instrument panel of LT models. Announced for this year was the availability of a leather interior option in the Camaro LT, but never saw the light of day as no production cars were equipped with real hide seats. Other developments included the availability of air conditioning with six-cylinder engines and standard radial tires on all models. Power door locks were a new option for 1975. The Rally Sport option returned after a one-year absence, but amounted to little more than an appearance package.


title: Chevrolet Camaro (second generation)

text: Despite the loss of the Z28, Camaro sales remained steady for 1975 at 145,770 units. With the demise of the other pony cars the previous year, Camaro and Pontiac's Firebird were now the only traditional pony cars left on the market, giving GM 100 percent penetration of this segment for the first time ever. Also, despite General Motors' policy against factory-sponsored racing efforts, Camaro began to make a name for itself on the track on the new International Race of Champions (IROC) series with many top drivers winning trophies from behind the wheel of a Camaro year after year until the late 1980s.


title: Chevrolet Camaro (second generation)

text: Only minor appearance changes highlighted the 1976 Camaro, most notably a brushed metal insert in the rear tail section on the LT model. The 250 cubic-inch six-cylinder remained the standard engine in the sport coupe and a new 305 cubic-inch V8 became the standard engine in the LT and base V8 option in the sport coupe. The larger 350 cubic-inch V8 was now only available with a four-barrel carburetor and . Power brakes became standard on V8 models this year. The Camaro's popularity was soaring. Sales totals jumped significantly for 1976, the best year yet for the second generation, and were to improve even more dramatically as the decade progressed.


title: Chevrolet Camaro (second generation)

text: The Z28 was reintroduced, as a model and not an RPO, to the buying public in the spring of 1977 as a "1977½" in response to increasing sales of Pontiac's Trans Am, which sold over 46,000 units in 1976 and accounted for half of all Firebird sales that year.The revived Z28 was powered by a V8 with four-barrel carburetor producing ( with California emissions equipment), with most cars sold equipped with air conditioning and an automatic transmission. The engine no longer came with the 4-bolt main bearing engine block, forged crank, forged pistons, big valve heads, and performance camshaft that had been part of the RPO Z28 Special Performance Package, the engine that had been shared with the Corvette LT-1 and L82 top-performance 350 engines from 1970 to 1974. The LM1 engine was the most powerful Camaro engine and only available in the Z28 model. The engine came with better tuned intake and exhaust, shared with most all Chevy passenger cars. The cars were also available with a Borg-Warner Super T-10 4-speed manual transmission.


title: Chevrolet Camaro (second generation)

text: Intermittent wipers were offered as a new option and the I-6 became the standard engine for both the sport coupe and luxury LT models. The continued as the base V8 and the four-barrel that was optional on sport coupe and LT models was uprated to . Due to General Motors' engine sharing program, the 350 CID Chevrolet engine was also used by Oldsmobile. This year the optional "Bumperettes" were offered for the LT models (front bumper only) and were mandatory for all Camaro models sold in the state of California.


title: Chevrolet Camaro (second generation)

text: Output set a record for the second-generation Camaro, with 218,853 coupes produced. The Camaro outsold Ford's Mustang for the first time ever. For 1977 Z28 production was around 13,000 cars with a 350 engine.


title: Chevrolet Camaro (second generation)

text: For the 1978 model year, the Camaro featured a new body colored urethane front and rear bumpers. Z28s featured a non-functioning hood scoop with outlining decal around the intake. The taillights were updated to include amber turn signals. Sales topped all previous years with 272,631 units, of which 54,907 were the Z28 model.


title: Chevrolet Camaro (second generation)

text: Available models included the base Sport Coupe, Type LT, Z28, and the return of the Rally Sport. The Rally Sport (not badged RS as in previous years) featured a standard two-tone paint treatment. The Z28 models included a stripe package that was not deletable and featured the LM1 a V8 with a four-barrel Quadrajet carburetor that produced and of torque coupled to either a 4-speed manual or a TH-350 3-speed automatic.


title: Chevrolet Camaro (second generation)

text: Another first for 1978 was T-Tops, although they were a regular production option on the 1977 Pontiac Firebird and were introduced on the 1976 Pontiac Trans Am 10th Anniversary Limited Edition.


title: Chevrolet Camaro (second generation)

text: The biggest changes for 1979 were the introduction of the luxury-oriented Berlinetta model, replacing the Type LT, and a restyled instrument panel with a much flatter appearance than the previous wraparound design (although the gauges themselves remained in the same places as before). The base models, RS and Z28 remained, the Z28s now came with a front spoiler and fender flares much like its Pontiac Trans Am twin had, and now came with "Z28" decals that ran from the beginning of the front flares to the bottoms of the doors. Electric rear window defroster became optional this year, replacing the old blower type. Sales for 1979 were the highest ever for any generation Camaro before or since, numbering 282,571 units. Engine choices remained with the 250 I6 standard in the base and RS models, with the 305 2bbl being an option and standard on the Berlinetta.


title: Chevrolet Camaro (second generation)

text: For 1980 the aged inline-six was replaced with a V6 engine, in California, a first for Camaro. The (4.4 L) 267 cu in V8 engine became an option on the base, RS and Berlinetta models this year. The Z28 hood included a rear-pointing raised scoop (air induction) with a solenoid operated flap which opened at full throttle, allowing the engine to breathe cooler air. A federally mandated speedometer also debuted this year, down from 130. Z28s had new optional grey 5-spoke rims (later used on the 1986–1988 Chevrolet Monte Carlo SS), a unique upper and lower front grill and smaller revised graphics on its doors. The side scoops were also changed from a louvered design to a flatter one with a single opening. The V8 was now only available on the Z28 this year.


title: Chevrolet Camaro (second generation)

text: The 1981 model was nearly unchanged from 1980 and would be the last model year for the second-generation Camaro. The Z28 was still powered by a V8, however due to new emissions regulations the engine was now equipped with a CCC (Computer Command Control) unit for the first time. This predecessor to modern engine control modules had an oxygen sensor, an electronically controlled carburetor, a throttle position sensor, coolant sensors, a barometric pressure sensor, a Manifold Absolute Pressure sensor (MAP), and a check engine light on the dash. The transmission was now equipped with a lockup torque converter, controlled by the CCC as well. The CCC could also be used as a self-diagnostic tool. However, as the goal of this change was strictly emissions reduction, horsepower dropped to . This engine was now only available with an automatic transmission, while the four-speed manual versions had the , which was the only engine offered in Z28s sold in California. Canadian models, however, could still get the 350 and 4-speed combination, and were not equipped with a CCC. Canadian 1981 Camaros were thus identical to 1980 US model. RS models were dropped this year, but the RS designation would reappear in 1989. Total production had dropped down to 126,139 from a high of 282,571 in 1979.


title: Broken But Beautiful

text: Broken But Beautiful is a 2018 Hindi romance web series, created by Ekta Kapoor, and available on video on demand platforms and ALTBalaji/MX Player. The series revolves around love, heartbreaks and never ending romance between two individuals. First two seasons are about the story of Veer and Sameera played by Vikrant Massey and Harleen Sethi respectively. The third season introduces a new story of Agastya and Rumi played by Sidharth Shukla and Sonia Rathee respectively.


title: Broken But Beautiful

text: "Broken But Beautiful season 1" is Veer and Sameera's story, where their hearts were left broken. Veer lost his wife Alina in a road accident 3 years ago but still hasn't been able to cope. Veer begins to hallucinate Alina and talks to her in his imagination. Alina's sister, Ishanvi and her husband Adil are motivating him to move on in his life and try to spend time with him. Due to unavoidable circumstances, Veer has to buy his cousin Kartik's house. Kartik broke up with his girlfriend Sameera 8 months ago and moved on to date Ananya. Sameera has been unable to forget Kartik and stalks him everywhere, unable to move on. Since the house belonged to Kartik and Sameera, Veer needs Sameera's signatures on the sale papers. When she signs the papers, Veer promises her to let her speak to Kartik one last time.


title: Broken But Beautiful

text: Veer and Sameera come up with a plan and pretend they are together to make Kartik jealous. The show then revolves around the budding relationship between Sameera and Veer.


title: Broken But Beautiful

text: Veer meets Debbie and Sameera meets Ahan. Veer and Sameera decide to marry Debbie and Ahan respectively. Then the show revolves around the realization of love for both Veer and Sameera towards each other.


title: Broken But Beautiful

text: As Veer and Sameera separate, Veer meets Debbie and start dating, while Sameera meets her classmate, Ahan who had a crush on her formerly. In the hope of bonding with her once again, Ahan asks Sameera out and she reluctantly agrees. They soon become great friends but Sameera's past experiences stop her from being in a relationship. Meanwhile, Veer and Sameera meet once again and become friends, deciding to move on from their past experiences. Sameera gets to know that Debbie is pregnant with Veer's child and that Veer has completely turned into the Sameera she was before and has now decided to marry Debbie. Feeling insecure, she starts seeing Ahan who is madly in love with her. Soon, Veer and Sameera talk about their feelings and become intimate in a drunken state. When they finally wake up the next morning, they realize their folly and decide to tell their respective partners. In mean time, Debbie realizes that she is not pregnant and tells it to Veer who panics and Ishanvi accidentally blurts out the truth and they break up. Sameera also tells Ahan who tells her to choose between him and the one she cheated on him with. Sameera chooses Ahan out of guilt and Ahan acts as a very supportive partner. Veer, on the other hand, confesses his love to Sameera who tells him about her former choice. Thus, they part ways yet again and this time Veer has a lot of difficulty in moving on. But fate has other plans of bringing them before each other as Sameera and Ahan decide to get married in Veer's resort. And the rest of the story revolves on how these two find their way back to each other.


title: Broken But Beautiful

text: Broken But Beautiful exhibits a determined and courageous Agastya Rao who is a struggling theatre writer-director with principles and truckloads of attitude who believes the mediocre world doesn't deserve someone as talented as him and a feisty Rumi Desai who come from a different strata of society. Rumi comes from a rich family, a spill-over of her mother's second marriage. She hates her stepsister who always manages to overshadow her. But when they meet, Agastya sees the talent and intensity in Rumi. They start an intense fling. Rumi is in love with Ishaan (Ehan Bhat) her rich and suave childhood friend and tells Agastya that they can't have a future together, but Agastya has fallen in love. He falls into a trap of drunkenness and depression and Rumi gets married. After a few years, Rumi divorces Ishaan and realises he never loved her like Agastya did.


title: Control system

text: A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial control systems which are used for controlling processes or machines. The control systems are designed via control engineering process.


title: Control system

text: For continuously modulated control, a feedback controller is used to automatically control a process or operation. The control system compares the value or status of the process variable (PV) being controlled with the desired value or setpoint (SP), and applies the difference as a control signal to bring the process variable output of the plant to the same value as the setpoint.


title: Control system

text: For sequential and combinational logic, software logic, such as in a programmable logic controller, is used.


title: Control system

text: There are two common classes of control action: open loop and closed loop. In an open-loop control system, the control action from the controller is independent of the process variable. An example of this is a central heating boiler controlled only by a timer. The control action is the switching on or off of the boiler. The process variable is the building temperature. This controller operates the heating system for a constant time regardless of the temperature of the building.


title: Control system

text: In a closed-loop control system, the control action from the controller is dependent on the desired and actual process variable. In the case of the boiler analogy, this would utilize a thermostat to monitor the building temperature, and feed back a signal to ensure the controller output maintains the building temperature close to that set on the thermostat. A closed-loop controller has a feedback loop which ensures the controller exerts a control action to control a process variable at the same value as the setpoint. For this reason, closed-loop controllers are also called feedback controllers.


title: Control system

text: In the case of linear feedback systems, a control loop including sensors, control algorithms, and actuators is arranged in an attempt to regulate a variable at a setpoint (SP). An everyday example is the cruise control on a road vehicle; where external influences such as hills would cause speed changes, and the driver has the ability to alter the desired set speed. The PID algorithm in the controller restores the actual speed to the desired speed in an optimum way, with minimal delay or overshoot, by controlling the power output of the vehicle's engine.


title: Control system

text: Control systems that include some sensing of the results they are trying to achieve are making use of feedback and can adapt to varying circumstances to some extent. Open-loop control systems do not make use of feedback, and run only in pre-arranged ways.


title: Control system

text: Logic control systems for industrial and commercial machinery were historically implemented by interconnected electrical relays and cam timers using ladder logic. Today, most such systems are constructed with microcontrollers or more specialized programmable logic controllers (PLCs). The notation of ladder logic is still in use as a programming method for PLCs.


title: Control system

text: Logic controllers may respond to switches and sensors and can cause the machinery to start and stop various operations through the use of actuators. Logic controllers are used to sequence mechanical operations in many applications. Examples include elevators, washing machines and other systems with interrelated operations. An automatic sequential control system may trigger a series of mechanical actuators in the correct sequence to perform a task. For example, various electric and pneumatic transducers may fold and glue a cardboard box, fill it with the product and then seal it in an automatic packaging machine.


title: Control system

text: PLC software can be written in many different ways – ladder diagrams, SFC (sequential function charts) or statement lists.


title: Control system

text: On–off control uses a feedback controller that switches abruptly between two states. A simple bi-metallic domestic thermostat can be described as an on-off controller. When the temperature in the room (PV) goes below the user setting (SP), the heater is switched on. Another example is a pressure switch on an air compressor. When the pressure (PV) drops below the setpoint (SP) the compressor is powered. Refrigerators and vacuum pumps contain similar mechanisms. Simple on–off control systems like these can be cheap and effective.


title: Control system

text: Linear control systems use negative feedback to produce a control signal to maintain the controlled PV at the desired SP. There are several types of linear control systems with different capabilities.


title: Control system

text: Proportional control is a type of linear feedback control system in which a correction is applied to the controlled variable which is proportional to the difference between the desired value (SP) and the measured value (PV). Two classic mechanical examples are the toilet bowl float proportioning valve and the fly-ball governor.


title: Control system

text: The proportional control system is more complex than an on–off control system, but simpler than a proportional-integral-derivative (PID) control system used, for instance, in an automobile cruise control. On–off control will work for systems that do not require high accuracy or responsiveness, but is not effective for rapid and timely corrections and responses. Proportional control overcomes this by modulating the manipulated variable (MV), such as a control valve, at a gain level that avoids instability, but applies correction as fast as practicable by applying the optimum quantity of proportional correction.


title: Control system

text: A drawback of proportional control is that it cannot eliminate the residual SP–PV error, as it requires an error to generate a proportional output. A PI controller can be used to overcome this. The PI controller uses a proportional term (P) to remove the gross error, and an integral term (I) to eliminate the residual offset error by integrating the error over time.


title: Control system

text: In some systems, there are practical limits to the range of the MV. For example, a heater has a limit to how much heat it can produce and a valve can open only so far. Adjustments to the gain simultaneously alter the range of error values over which the MV is between these limits. The width of this range, in units of the error variable and therefore of the PV, is called the "proportional band" (PB).


title: Control system

text: When controlling the temperature of an industrial furnace, it is usually better to control the opening of the fuel valve "in proportion to" the current needs of the furnace. This helps avoid thermal shocks and applies heat more effectively.


title: Control system

text: At low gains, only a small corrective action is applied when errors are detected. The system may be safe and stable, but may be sluggish in response to changing conditions. Errors will remain uncorrected for relatively long periods of time and the system is overdamped. If the proportional gain is increased, such systems become more responsive and errors are dealt with more quickly. There is an optimal value for the gain setting when the overall system is said to be critically damped. Increases in loop gain beyond this point lead to oscillations in the PV and such a system is underdamped. Adjusting gain to achieve critically damped behavior is known as "tuning" the control system.


title: Control system

text: In the underdamped case, the furnace heats quickly. Once the setpoint is reached, stored heat within the heater sub-system and in the walls of the furnace will keep the measured temperature rising beyond what is required. After rising above the setpoint, the temperature falls back and eventually heat is applied again. Any delay in reheating the heater sub-system allows the furnace temperature to fall further below setpoint and the cycle repeats. The temperature oscillations that an underdamped furnace control system produces are undesirable.


title: Control system

text: In a critically damped system, as the temperature approaches the setpoint, the heat input begins to be reduced, the rate of heating of the furnace has time to slow and the system avoids overshoot. Overshoot is also avoided in an overdamped system but an overdamped system is unnecessarily slow to initially reach setpoint respond to external changes to the system, e.g. opening the furnace door.


title: Control system

text: Pure proportional controllers must operate with residual error in the system. Though PI controllers eliminate this error they can still be sluggish or produce oscillations. The PID controller addresses these final shortcomings by introducing a derivative (D) action to retain stability while responsiveness is improved.


title: Control system

text: The derivative is concerned with the rate-of-change of the error with time: If the measured variable approaches the setpoint rapidly, then the actuator is backed off early to allow it to coast to the required level; conversely, if the measured value begins to move rapidly away from the setpoint, extra effort is applied—in proportion to that rapidity to help move it back.


title: Control system

text: On control systems involving motion control of a heavy item like a gun or camera on a moving vehicle, the derivative action of a well-tuned PID controller can allow it to reach and maintain a setpoint better than most skilled human operators. If a derivative action is over-applied, it can, however, lead to oscillations.


title: Control system

text: The integral term magnifies the effect of long-term steady-state errors, applying an ever-increasing effort until the error is removed. In the example of the furnace above working at various temperatures, if the heat being applied does not bring the furnace up to setpoint, for whatever reason, integral action increasingly "moves" the proportional band relative to the setpoint until the PV error is reduced to zero and the setpoint is achieved.


title: Control system

text: Some controllers include the option to limit the "ramp up % per minute". This option can be very helpful in stabilizing small boilers (3 MBTUH), especially during the summer, during light loads. A utility boiler "unit may be required to change load at a rate of as much as 5% per minute (IEA Coal Online - 2, 2007)".


title: Control system

text: It is possible to filter the PV or error signal. Doing so can help reduce instability or oscillations by reducing the response of the system to undesirable frequencies. Many systems have a resonant frequency. By filtering out that frequency, stronger overall feedback can be applied before oscillation occurs, making the system more responsive without shaking itself apart.


title: Control system

text: Feedback systems can be combined. In cascade control, one control loop applies control algorithms to a measured variable against a setpoint but then provides a varying setpoint to another control loop rather than affecting process variables directly. If a system has several different measured variables to be controlled, separate control systems will be present for each of them.


title: Control system

text: Control engineering in many applications produces control systems that are more complex than PID control. Examples of such field applications include fly-by-wire aircraft control systems, chemical plants, and oil refineries. Model predictive control systems are designed using specialized computer-aided-design software and empirical mathematical models of the system to be controlled.


title: Control system

text: Fuzzy logic is an attempt to apply the easy design of logic controllers to the control of complex continuously varying systems. Basically, a measurement in a fuzzy logic system can be partly true.


title: Control system

text: The rules of the system are written in natural language and translated into fuzzy logic. For example, the design for a furnace would start with: "If the temperature is too high, reduce the fuel to the furnace. If the temperature is too low, increase the fuel to the furnace."


title: Control system

text: Measurements from the real world (such as the temperature of a furnace) are "fuzzified" and logic is calculated arithmetic, as opposed to Boolean logic, and the outputs are "de-fuzzified" to control equipment.


title: Control system

text: When a robust fuzzy design is reduced to a single, quick calculation, it begins to resemble a conventional feedback loop solution and it might appear that the fuzzy design was unnecessary. However, the fuzzy logic paradigm may provide scalability for large control systems where conventional methods become unwieldy or costly to derive.


title: Control system

text: Fuzzy electronics is an electronic technology that uses fuzzy logic instead of the two-value logic more commonly used in digital electronics.


title: Control system

text: The range of control system implementation is from compact controllers often with dedicated software for a particular machine or device, to distributed control systems for industrial process control for a large physical plant.


title: Manoj Tiwari (politician)

text: Manoj Kumar Tiwari (born 1 February 1971) is an Indian politician, singer and actor serving as a Member of Parliament from North East Delhi. He contested the 2009 general election as a Samajwadi Party candidate from Gorakhpur Lok Sabha but lost to Yogi Adityanath. Again, he contested 2014 Indian general elections as a Bharatiya Janata Party (BJP) candidate and won. He was appointed as Delhi BJP president in 2016. He was the head of the BJP organisation in Delhi when the party recorded a record victory in 2017 MCD elections. He was a contestant in Bigg Boss season 4.


title: Manoj Tiwari (politician)

text: Born on 1 February 1971 in Kabir Chaura locality of Varanasi in Uttar Pradesh, Tiwari is one of the six children of Chandradev Tiwari and Lalita Devi. He is from Atarwalia, a small village in Kaimur district of Bihar. Tiwari completed his M.P.Ed. degree from Banaras Hindu University.


title: Manoj Tiwari (politician)

text: Prior to his involvement in politics, he had spent years as a singer and an actor in the Bhojpuri film industry.


title: Manoj Tiwari (politician)

text: In 2003, he took a role in the film "Sasura Bada Paisawala". He followed this with the films "Daroga Babu I Love You" and "Bandhan Toote Na".


title: Manoj Tiwari (politician)

text: The BBC reported in 2005 that Tiwari and Ravi Kishan were the biggest male stars in the Bhojpuri cinema market and that Tiwari charged around 90,000 per film.


title: Manoj Tiwari (politician)

text: In 2009, Tiwari contested elections for the 15th Lok Sabha as a candidate for the Samajwadi Party in the Gorakhpur constituency. He had been offered a choice of three constituencies and "Zeenews" reported him as saying that he was not "a political person but was concerned for the development of Purvanchal region of Uttar Pradesh." He lost to Yogi Adityanath.


title: Manoj Tiwari (politician)

text: His house in Mumbai was allegedly attacked in November 2009 by an irate mob about remarks that they claimed he had made about Shiv Sena. Tiwari denied the allegations.


title: Manoj Tiwari (politician)

text: In January 2011 "Mid-Day" reported that the BJP might invite him to join their party and that the association with him would assist their electoral efforts among North Indians. Tiwari dismissed the story as being hypothetical, although he would consider his options should an invitation emerge. He had been seen with BJP leaders at an event and had expressed admiration for Shatrughan Sinha, the BJP MP for Patna Sahib.


title: Manoj Tiwari (politician)

text: Tiwari has supported Ramdev's hunger strike at the Ramlila Ground protests and protested the arrest of Anna Hazare.


title: Manoj Tiwari (politician)

text: He won the North East Delhi (Lok Sabha constituency) in the 2014 Indian general elections from BJP. He defeated Anand Kumar from AAP with a margin of 1,44,084 votes.


title: Manoj Tiwari (politician)

text: In 2019 general elections, Tiwari, a BJP candidate won against Indian National Congress candidate Sheila Dikshit in North East Delhi constituency of New Delhi by a margin of 3.63 lakh votes.


title: Manoj Tiwari (politician)

text: The Delhi government had decided to stop the production, storage, sale, and use of all types of firecrackers to reduce the rising levels of pollution in Delhi. In September 2022, Tiwari moved the Supreme Court against the Delhi government. Tiwari said that that freedom of religion cannot be taken away under the pretext of the right to life. Supreme Court refused to provide an early hearing for the petition and dismissed the plea saying "Let People Breathe Clean Air". SC also asked the public to use the money on sweets instead of crackers.


title: Manoj Tiwari (politician)

text: Manoj Tiwari married his first wife Rani Tiwari in 1999. They have a daughter together named Rhiti. In 2011, Manoj and Rani were involved in divorce proceedings, after 11 years of marriage. They divorced in 2012.


title: Manoj Tiwari (politician)

text: He later married Surbhi, with whom he has two daughters. The first daughter born on 30 December 2020 and second on 12 December 2022.


title: Megan's Law

text: Megan's Law is the name for a federal law (and informal name for subsequent state laws) in the United States requiring law enforcement authorities to make information available to the public regarding registered sex offenders. Laws were created in response to the murder of Megan Kanka. Federal Megan's Law was enacted as a subsection of the Jacob Wetterling Crimes Against Children and Sexually Violent Offender Registration Act of 1994, which merely required sex offenders to register with local law enforcement. Since only a few states required registration prior to Megan's death, the state level legislation to bring states in compliance—with both the "registration" requirement of Jacob Wetterling Act and "community notification" required by federal Megan's Law—were crafted simultaneously and are often referred to as "Megan's Laws" of individual states. Thus, federal Megan's Law refers to "community notification" (making registry information public), whereas state level "Megan's Law" may refer to both "sex offender registration" and "community notification".


title: Megan's Law

text: Individual states decide what information will be made available and how it should be disseminated. For example, they disseminate the information via social media platforms such as Facebook. Commonly included information is the offender's name, picture, address, incarceration date, and offense of conviction. The information is often displayed on free public websites, but can be published in newspapers, distributed in pamphlets, or through various other means.


title: Megan's Law

text: At the federal level, Megan's Law requires persons convicted of sex crimes against children to notify local law enforcement of any change of address or employment after release from custody (prison or psychiatric facility). The notification requirement may be imposed for a fixed period of time—usually at least ten years—or permanently. Some states may legislate registration for all sex crimes, even if no minors were involved. It is a felony in most jurisdictions to fail to register or fail to update information.


title: Megan's Law

text: Together, the Wetterling Act and Megan's Law provide two major information services: sex offender registry for law enforcement, and community notification for the public. The details of what is provided as part of sex offender registration and how community notification is handled vary from state to state, and in some states the required registration information and community notification protocols have changed many times since Megan's Law was passed. The Adam Walsh Child Protection and Safety Act supplements Megan's Law with new registration requirements and a three-tier system for classifying sex offenders according to certain listed offenses requiring registration.


title: Megan's Law

text: Precedent of Megan's Law, federal Jacob Wetterling Act of 1994, required each state to create a registry for sexual offenders and certain other offenses against children. Under the Wetterling Act, registry information was kept for law enforcement use only, although law enforcement agencies were allowed to release the information of specific persons when deemed necessary to protect the public. After the high-profile rape and murder of seven-year-old Megan Kanka in Hamilton Township, Mercer County, New Jersey by Jesse Timmendequas, a sex offender with two previous convictions of sex crimes against small children living across the street from Megan, her parents Richard and Maureen Kanka worked to change the law by demanding mandatory community notification of sex offenders, arguing that the registration required under the Jacob Wetterling Act was not a sufficient protection measure. They said that Megan would still be alive had they known of the criminal history of Timmendequas. Paul Kramer sponsored a package of seven bills known as Megan's Law New Jersey General Assembly in 1994. 89 days after Megan was murdered, New Jersey enacted Megan's Law, which required sex offender registration, with a database tracked by the state, and whereabouts of "high-risk sex offenders" moving into a neighborhood to be made public. Before Megan's death, only five states required sex offenders to register with local law enforcement as required in Jacob Wetterling Act.


title: Megan's Law

text: The New Jersey law became model for federal legislation, introduced in the House of Representatives by Congressman Dick Zimmer. On May 17, 1996, President Bill Clinton signed federal Megan's Law, an amendment to the Jacob Wetterling Act, that set the guidelines for the state statutes, requiring states to notify the public, although officials could decide how much public notification is necessary, based on the level of danger posed by an offender.


title: Megan's Law

text: International Megan's Law to Prevent Child Exploitation and Other Sexual Crimes Through Advanced Notification of Traveling Sex Offenders was signed into a law by President Obama on February 8, 2016. International Megan's Law requires the notification of foreign governments when a citizen of United States registered as a sex offender for sexual offense involving a minor is going to be traveling to their country. The law requires a visual "unique identifier" to be placed on the passports of covered registrants and requires offenders to notify law enforcement 21 days before traveling abroad. The law was challenged shortly after being enacted.


title: Megan's Law

text: States differ with respect to public disclosure of offenders. In some states all sex offenders are subject to public notification through Megan's Law websites. However, in others, only information on high-risk offenders is publicly available, and the complete lists are withheld for law enforcement only. Under federal SORNA "tier I" registrants may be excluded from public disclosure, with exemption of those convicted of "specified offense against a minor." Since SORNA merely sets the minimum standards the states must follow, many SORNA compliant states disclose information of all tiers. These disparities have prompted some registrants to move into states with less strict rules.


title: Megan's Law

text: Evidence to support the effectiveness of public sex offender registries is limited and mixed. Majority of research results do not find statistically significant shift in sexual offense trends following the implementation of sex offender registration and notification (SORN) regimes. A few studies indicate that sexual recidivism may have been lowered by SORN policies, while a few have found statistically significant increase in sex crimes following SORN implementation. According to the Office of Justice Programs' SMART Office, sex offender registration and notification requirements arguably have been implemented in the absence of empirical evidence regarding their effectiveness.


title: Megan's Law

text: Opponents of Megan's Law, like Women Against Registry, National Association for Rational Sexual Offense Laws, and Human Rights Watch, have called the law overbroad and an invitation to vigilante violence.


title: Megan's Law

text: Treatment professionals such as ATSA criticize the lack of evidence of the laws' effectiveness, the automatic inclusion of offenders on the registry without determining the risk of reoffense (by applying scientifically validated risk assessment tools), the scientifically unsupported popular belief in high recidivism, and the counter-effectiveness of the laws, which can actually undermine, rather than improve public safety by exacerbating factors (e.g. unemployment, instability) that may lead to recidivism. In addition, civil rights and reformist organizations highlight the adverse collateral effects on the family members of registrants, and question the fairness of the registries as indefinite punishment, and when applied to certain offender groups, such as juveniles and young adults engaging in consensual acts. Some victims' rights advocates like Patty Wetterling have presented similar critique.


title: Sandahl Bergman

text: Sandahl Bergman is an American actress and dancer. She is best known for her role as Valeria in the film "Conan the Barbarian" (1982), for which she won a Golden Globe and a Saturn Award.


title: Sandahl Bergman

text: Bergman was born in Kansas City, Missouri. She graduated from Shawnee Mission East High School in Prairie Village, Kansas. She grew up tall, athletic, and statuesque.


title: Sandahl Bergman

text: In her 20s, she moved to New York City and appeared in a number of Broadway shows, catching the eye of choreographer Bob Fosse, who cast her as a replacement dancer in "Pippin". She had a secondary lead in the stage version of the film "Gigi" in 1973, and later appeared in "Mack & Mabel", and as Judy in the renowned "new New York cast" of "A Chorus Line" (when many of the original actors left the show in 1977). She was cast again by Fosse in his critically acclaimed 1978 dance concert/musical "Dancin'", which featured many of the top dancers on Broadway at the time.


title: Sandahl Bergman

text: Bergman's movie career began in 1978 with a small role in the TV film "How to Pick Up Girls". She followed that in 1979 with the Bob Fosse film "All That Jazz", in which she was a featured performer in the "Take Off With Us" sequence. In the 1980 movie "Xanadu", she appears as one of the nine immortal Muses during the opening song "I'm Alive" by ELO, as well as the final title number of "Xanadu".


title: Sandahl Bergman

text: Bergman's participation in "Xanadu" also led indirectly to her eviction from her apartment in New York and subsequent relocation to California. She had been subletting her apartment in New York in defiance of a clause in her agreement with her landlord, and during her four months in California for filming, he became aware of the situation. Bergman has said she did not return to New York, instead having friends pack and ship her belongings to her.


title: Sandahl Bergman

text: Her best-known role was playing Valeria opposite Arnold Schwarzenegger in the 1982 film "Conan the Barbarian". She won the Golden Globe Award for New Star of the Year - Actress for her role in the film. Because no stunt women could be found to match her size, she learned to do all her own stunt work. She commented on the experience, "It was tough. I nearly lost a finger. Arnold smashed his head against a rock. But that was nothing compared to what the stunt men went through."


title: Sandahl Bergman

text: In 1984 she played the titular role in the post-apocalytic comedy-adventure "She", while she played queen Gedren the next year in "Red Sonja". She was offered the title role, but asked to play the villainess instead. After that, she appeared in a series of low-budget films, such as 1987's "Hell Comes to Frogtown". Her most recent work was in 2003, when at the age of 52 she appeared as a dancer in the film version of "The Singing Detective". Other appearances include a lunar base officer in the movie "", the music video "Heavy Metal Love" by the band Helix and the Fred Olen Ray film "Possessed by the Night", and guest appearances on television, such as "Hart to Hart" and a dance sequence choreographed by Stanley Donen in an episode of "Moonlighting".


title: Sandahl Bergman

text: Bergman has since retired from acting, but still makes the occasional appearance at sci-fi conventions.


title: Masaki Suda

text: , known professionally as , is a Japanese actor and singer. He won the Japan Academy Film Prize for Outstanding Performance by an Actor in a Leading Role. His debut song is "Mita Koto mo Nai Keshiki".


title: Masaki Suda

text: Suda is a close junior to Shun Oguri and Takayuki Yamada. His friends are Kento Yamazaki, Taiga Nakano and Fumi Nikaido. He worked with Kenshi Yonezu, Huwie Ishizaki and Aimyon at the music industry. Suda married Nana Komatsu on November 15, 2021.


title: Masaki Suda

text: Suda met talent agents while at school. He had several auditions, and was a finalist at Amuse, Inc. and . He played Philip in the tokusatsu series, "Kamen Rider W". His film debut after "Kamen Rider" was in "The Backwater". He won the Best New Actor Award from Tama Cinema Forum. He played Akuma in "Shinigami-kun" and Karma Akabane in "Assassination Classroom". Suda starred in the web series "" and its . He won the Japan Academy Film Prize for Outstanding Performance by an Actor in a Leading Role in "Wilderness" and starred in "My Little Monster".


title: Masaki Suda

text: He appeared in the biopic film about Hide of the group Greeeen. They released an EP, "Green Boys". Suda released a few albums, "Play" and "Love".


title: Lerwick

text: Lerwick (; ; ) is the main town and port of the Shetland archipelago, Scotland. Shetland's only burgh, Lerwick had a population of about 7,000 residents in 2010.


title: Lerwick

text: Centred off the north coast of the Scottish mainland and on the east coast of the Shetland Mainland, Lerwick lies north-by-northeast of Aberdeen; west of the similarly sheltered port of Bergen in Norway; and south east of Tórshavn in the Faroe Islands. One of the UK's coastal weather stations is situated there, with the local climate having small seasonal variation due to the maritime influence. Being located further north than Saint Petersburg and the three mainland Nordic capitals, Lerwick's nights in the middle of summer only get dark twilight and winters have below six hours of complete daylight.


title: Lerwick

text: Lerwick is a name with roots in Old Norse and its local descendant, Norn, which was spoken in Shetland until the mid-19th century. The name "Lerwick" means "bay of clay". The corresponding Norwegian name is , meaning clay and meaning "bay" or "inlet". Towns with similar names exist in southwestern Norway (, ) and on the Faroe Islands ().


title: Lerwick

text: Evidence of human settlement in the Lerwick area dates back to the Neolithic (4000–2500 BC) and the Bronze Age (2500–800 BC) known from paleoenvironmental records for human activity and the recovery of artefacts, including a stone axe head submerged in Bressay Sound. Iron Age (800 BC – AD 800) settlement is known at the Broch of Clickimin, which was constructed as early as 400 BC. The first settlement to be known as Lerwick was founded in the 17th century as a herring and white fish seaport to trade with the Dutch fishing fleet. This settlement was on the mainland (west) side of Bressay Sound, a natural harbour with south and north entrances between the Shetland mainland and the island of Bressay. Its collection of wooden huts was burned to the ground twice: once in the 17th century by the residents of Scalloway on the western side of Mainland, then the capital of Shetland, who disapproved of the immoral and drunken activities of the assembled fishermen and sailors; again in 1702 by the French fleet.


title: Lerwick

text: Fort Charlotte was built in the mid 17th century on Lerwick's waterfront, and permanent stone-built buildings began to be erected around the fort and along the shoreline. The principal concentration of buildings was in the "lanes" area: a steep hillside stretching from the shoreline to Hillhead at the top. Lerwick became capital of the Shetland Islands in 1708, taking over the function from Scalloway. The civil parish of Lerwick had been in 1701 created from a small part of the parish of Tingwall, to which Scalloway still belongs. When Lerwick became more prosperous through sea trade and the fishing industry during the 19th century, the town expanded in 1891 to the west of Hillhead, thereby including the former civil parishes of Gulberwick and Quarff, as well as the islands parish of Burra. Lerwick Town Hall was built during this period of expansion.


title: Lerwick

text: Lerwick war memorial dates from 1923 and was designed by Sir Robert Lorimer. The next period of significant expansion was during the North Sea oil boom of the 1970s when large housing developments were built to the north of Staney Hill (located in Lerwick) and to the south (Nederdale and Sandveien).


title: Lerwick

text: Lerwick has transitioned from a subpolar oceanic climate ("Cfc") to a maritime climate ("Cfb") with cool to cold temperatures all year long. The lack of trees reflects the latter type. This is particularly pronounced by virtue of Lerwick being on the coast of an island, so even extreme temperature records are subdued; the record high stands at just (July 1991) and the record low just (January 1952 and January 1959). Lerwick is also a very cloudy town, averaging only 1,110 sunshine hours annually. February is the coldest month, with high temperatures averaging around . In August, the warmest month, average high temperatures are near . This produces an extremely narrow difference for an area north of the 60 parallel. In terms of average monthly precipitation, October to January are the year's wettest months, with over of precipitation each month; May and June are the driest months, with average monthly precipitation less than each. Snowfall can occur, primarily from December to March, but snow accumulation is rarely heavy and usually short-lived. The exposed North Atlantic location and proximity to autumn and winter storm tracks means high winds are a regular occurrence, alongside high levels of cloudiness and precipitation. Temperatures are likely to be slightly milder in the town centre at sea level, as the weather station is at an elevation of .


title: Lerwick

text: Owing to its northerly location, winter months are extremely dark in Lerwick. On the day of the winter solstice it gets only 5 hours and 49 minutes of daylight. In sharp contrast daylight lasts 18 hours and 55 minutes on the day of the summer solstice. As a result, nights never get completely dark for a period of time in summer, with dark blue elements remaining in the sky. The maritime influence tempers the climate effects of these swings in daylight, but in many areas of the world this latitude has hostile winters. Farther north in the world, only the Faroe Islands have such high January averages as Lerwick and fellow Shetland station at Baltasound – with the warm Atlantic currents preventing ice formation. Only when temperatures in continental areas are record cold does Lerwick experience some cold as was the case in December 2010 during the severe cold wave affecting the British Isles and Europe that covered much of mainland UK in snow. Even so, average highs remained above and frosts were light. Even warm summers are also extremely rare with the warmest recorded month being July 2006 at an average high of .


title: Lerwick

text: Lerwick has 6,958 residents, as of 2011. It is 97.0% White (83.3% White Scottish, 8.9% White Other British, 2.6% White Other, 1.4% White Polish, 0.8% White Irish), 2.2% Asian or Asian Scottish or British Asian, and 0.8% other ethnic groups. Lerwick's residents are 2.5% unemployed, 17.3% are part-time employees, and 50.3% are full-time employees.


title: Lerwick

text: Lerwick is a busy fishing and ferry port. The harbour also services vessels supporting the offshore oil industry.


title: Lerwick

text: Significant buildings in Lerwick include Fort Charlotte, Lerwick Town Hall, the Böd of Gremista, Shetland Museum and Broch of Clickimin.


title: Lerwick

text: Because of the historic nature of the area, some scenes from BBC's "Shetland" were filmed in Lerwick.


title: Lerwick

text: Lerwick is served by the Tingwall Airport located a few miles away and Sumburgh Airport that is further south and flies all year to some Scotland destinations.


title: Lerwick

text: NorthLink Ferries operate a daily overnight ferry service between Lerwick and Aberdeen, regularly calling in to Kirkwall in the Orkney Islands.


title: Lerwick

text: The Shetland Islands Council operate a ro-ro ferry service to Out Skerries and Bressay from a terminal in the centre of the town.


title: Lerwick

text: The local bus service is provided by the Regional Transport Partnership (ZetTrans) and operated by a number of different local bus service operators. The town has a bus station, Viking bus station.


title: Lerwick

text: Shetland College, a constituent partner institution of the University of the Highlands and Islands, is also based in the town, offering degree-level education (along with further education courses) to locals who may have difficulty travelling further afield to study.


title: Lerwick

text: The Gilbert Bain Hospital provides secondary care services to all of Shetland. The Montfield Hospital, a few hundred metres away, is an older hospital than the Gilbert Bain, but has become a secondary health care service for the people of Lerwick over time.


title: Lerwick

text: The town is home to four football teams, Lerwick Spurs, Lerwick Thistle, Lerwick Celtic and Lerwick Rangers.


title: Lerwick

text: Local independent radio station SIBC broadcasts daily from a studio in Market Street. BBC Radio Shetland, a BBC Radio Scotland regional opt out, has its studios in Pitt Lane. "The Shetland Times", a weekly local newspaper, has its premises in Gremista on the northern outskirts of Lerwick. Millgaet Media Group, a multi-media production company, is based at the North Ness Business Park.


title: Lerwick

text: Lerwick has strong ties with Scandinavian countries, particularly Norway (Lerwick has a friendship agreement with Måløy in Norway).


title: Lerwick

text: Lerwick is the focus of most events in Shetland, including the largest of the annual Up Helly Aa fire festivals which takes place on the last Tuesday of January every year.


title: Power set

text: In mathematics, the power set (or powerset) of a set is the set of all subsets of , including the empty set and itself. In axiomatic set theory (as developed, for example, in the ZFC axioms), the existence of the power set of any set is postulated by the axiom of power set.


title: Power set

text: The powerset of is variously denoted as , , , formula_1, or . The notation , meaning the set of all functions from S to a given set of two elements (e.g., {0, 1}), is used because the powerset of can be identified with, equivalent to, or bijective to the set of all the functions from to the given two elements set.


title: Power set

text: If is a finite set with the cardinality (i.e., the number of all elements in the set is ), then the number of all the subsets of is . This fact as well as the reason of the notation denoting the power set are demonstrated in the below.


title: Power set

text: Cantor's diagonal argument shows that the power set of a set (whether infinite or not) always has strictly higher cardinality than the set itself (or informally, the power set must be larger than the original set). In particular, Cantor's theorem shows that the power set of a countably infinite set is uncountably infinite. The power set of the set of natural numbers can be put in a one-to-one correspondence with the set of real numbers (see Cardinality of the continuum).


title: Power set

text: The power set of a set , together with the operations of union, intersection and complement, can be viewed as the prototypical example of a Boolean algebra. In fact, one can show that any "finite" Boolean algebra is isomorphic to the Boolean algebra of the power set of a finite set. For "infinite" Boolean algebras, this is no longer true, but every infinite Boolean algebra can be represented as a subalgebra of a power set Boolean algebra (see Stone's representation theorem).


title: Power set

text: The power set of a set forms an abelian group when it is considered with the operation of symmetric difference (with the empty set as the identity element and each set being its own inverse), and a commutative monoid when considered with the operation of intersection. It can hence be shown, by proving the distributive laws, that the power set considered together with both of these operations forms a Boolean ring.


title: Power set

text: In set theory, is the notation representing the set of all functions from to . As "2" can be defined as (see, for example, von Neumann ordinals), (i.e., ) is the set of all functions from to . As shown above, and the power set of , , is considered identical set-theoretically.


title: Power set

text: This equivalence can be applied to the example above, in which , to get the isomorphism with the binary representations of numbers from 0 to , with being the number of elements in the set or . First, the enumerated set is defined in which the number in each ordered pair represents the position of the paired element of in a sequence of binary digits such as ; of is located at the first from the right of this sequence and is at the second from the right, and 1 in the sequence means the element of corresponding to the position of it in the sequence exists in the subset of for the sequence while 0 means it does not.


title: Power set

text: Such a bijective mapping from to integers is arbitrary, so this representation of all the subsets of is not unique, but the sort order of the enumerated set does not change its cardinality. (E.g., can be used to construct another bijective from to the integers without changing the number of one-to-one correspondences.)


title: Power set

text: However, such finite binary representation is only possible if "S" can be enumerated. (In this example, , , and are enumerated with 1, 2, and 3 respectively as the position of binary digit sequences.) The enumeration is possible even if has an infinite cardinality (i.e., the number of elements in is infinite), such as the set of integers or rationals, but not possible for example if "S" is the set of real numbers, in which case we cannot enumerate all irrational numbers.


title: Power set

text: The binomial theorem is closely related to the power set. A –elements combination from some set is another name for a –elements subset, so the number of combinations, denoted as (also called binomial coefficient) is a number of subsets with elements in a set with elements; in other words it's the number of sets with elements which are elements of the power set of a set with elements.


title: Power set

text: The set of subsets of of cardinality less than or equal to is sometimes denoted by or , and the set of subsets with cardinality strictly less than is sometimes denoted or . Similarly, the set of non-empty subsets of might be denoted by or .


title: Power set

text: A set can be regarded as an algebra having no nontrivial operations or defining equations. From this perspective, the idea of the power set of as the set of subsets of generalizes naturally to the subalgebras of an algebraic structure or algebra.


title: Power set

text: The power set of a set, when ordered by inclusion, is always a complete atomic Boolean algebra, and every complete atomic Boolean algebra arises as the lattice of all subsets of some set. The generalization to arbitrary algebras is that the set of subalgebras of an algebra, again ordered by inclusion, is always an algebraic lattice, and every algebraic lattice arises as the lattice of subalgebras of some algebra. So in that regard, subalgebras behave analogously to subsets.


title: Power set

text: However, there are two important properties of subsets that do not carry over to subalgebras in general. First, although the subsets of a set form a set (as well as a lattice), in some classes it may not be possible to organize the subalgebras of an algebra as itself an algebra in that class, although they can always be organized as a lattice. Secondly, whereas the subsets of a set are in bijection with the functions from that set to the set {0,1} = 2, there is no guarantee that a class of algebras contains an algebra that can play the role of 2 in this way.


title: Power set

text: Certain classes of algebras enjoy both of these properties. The first property is more common, the case of having both is relatively rare. One class that does have both is that of multigraphs. Given two multigraphs and , a homomorphism consists of two functions, one mapping vertices to vertices and the other mapping edges to edges. The set of homomorphisms from to can then be organized as the graph whose vertices and edges are respectively the vertex and edge functions appearing in that set. Furthermore, the subgraphs of a multigraph are in bijection with the graph homomorphisms from to the multigraph definable as the complete directed graph on two vertices (hence four edges, namely two self-loops and two more edges forming a cycle) augmented with a fifth edge, namely a second self-loop at one of the vertices. We can therefore organize the subgraphs of as the multigraph , called the power object of .


title: Power set

text: What is special about a multigraph as an algebra is that its operations are unary. A multigraph has two sorts of elements forming a set of vertices and of edges, and has two unary operations giving the source (start) and target (end) vertices of each edge. An algebra all of whose operations are unary is called a presheaf. Every class of presheaves contains a presheaf that plays the role for subalgebras that 2 plays for subsets. Such a class is a special case of the more general notion of elementary topos as a category that is closed (and moreover cartesian closed) and has an object , called a subobject classifier. Although the term "power object" is sometimes used synonymously with exponential object , in topos theory is required to be .


title: Power set

text: In category theory and the theory of elementary topoi, the universal quantifier can be understood as the right adjoint of a functor between power sets, the inverse image functor of a function between sets; likewise, the existential quantifier is the left adjoint.


title: Ruthenium

text: Ruthenium is a chemical element with the symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most other chemicals. Russian-born scientist of Baltic-German ancestry Karl Ernst Claus discovered the element in 1844 at Kazan State University and named ruthenium in honor of Russia. Ruthenium is usually found as a minor component of platinum ores; the annual production has risen from about 19 tonnes in 2009 to some 35.5 tonnes in 2017. Most ruthenium produced is used in wear-resistant electrical contacts and thick-film resistors. A minor application for ruthenium is in platinum alloys and as a chemistry catalyst. A new application of ruthenium is as the capping layer for extreme ultraviolet photomasks. Ruthenium is generally found in ores with the other platinum group metals in the Ural Mountains and in North and South America. Small but commercially important quantities are also found in pentlandite extracted from Sudbury, Ontario and in pyroxenite deposits in South Africa.


title: Ruthenium

text: Ruthenium, a polyvalent hard white metal, is a member of the platinum group and is in group 8 of the periodic table:


title: Ruthenium

text: Whereas all other group 8 elements have two electrons in the outermost shell, in ruthenium, the outermost shell has only one electron (the final electron is in a lower shell). This anomaly is observed in the neighboring metals niobium (41), molybdenum (42), and rhodium (45).


title: Ruthenium

text: Ruthenium has four crystal modifications and does not tarnish at ambient conditions; it oxidizes upon heating to . Ruthenium dissolves in fused alkalis to give ruthenates (). It is not attacked by acids (even aqua regia) but is attacked by halogens at high temperatures. Indeed, ruthenium is most readily attacked by oxidizing agents. Small amounts of ruthenium can increase the hardness of platinum and palladium. The corrosion resistance of titanium is increased markedly by the addition of a small amount of ruthenium. The metal can be plated by electroplating and by thermal decomposition. A ruthenium-molybdenum alloy is known to be superconductive at temperatures below 10.6 K. Ruthenium is the only 4d transition metal that can assume the group oxidation state +8, and even then it is less stable there than the heavier congener osmium: this is the first group from the left of the table where the second and third-row transition metals display notable differences in chemical behavior. Like iron but unlike osmium, ruthenium can form aqueous cations in its lower oxidation states of +2 and +3.


title: Ruthenium

text: Ruthenium is the first in a downward trend in the melting and boiling points and atomization enthalpy in the 4d transition metals after the maximum seen at molybdenum, because the 4d subshell is more than half full and the electrons are contributing less to metallic bonding. (Technetium, the previous element, has an exceptionally low value that is off the trend due to its half-filled [Kr]4d5s configuration, though it is not as far off the trend in the 4d series as manganese in the 3d transition series.) Unlike the lighter congener iron, ruthenium is paramagnetic at room temperature, as iron also is above its Curie point.


title: Ruthenium

text: Naturally occurring ruthenium is composed of seven stable isotopes. Additionally, 34 radioactive isotopes have been discovered. Of these radioisotopes, the most stable are Ru with a half-life of 373.59 days, Ru with a half-life of 39.26 days and Ru with a half-life of 2.9 days.


title: Ruthenium

text: Fifteen other radioisotopes have been characterized with atomic weights ranging from 89.93 u (Ru) to 114.928 u (Ru). Most of these have half-lives that are less than five minutes except Ru (half-life: 1.643 hours) and Ru (half-life: 4.44 hours).


title: Ruthenium

text: The primary decay mode before the most abundant isotope, Ru, is electron capture and the primary mode after is beta emission. The primary decay product before Ru is technetium and the primary decay product after is rhodium.


title: Ruthenium

text: Ru is a product of fission of a nucleus of uranium or plutonium. High concentrations of detected atmospheric Ru were associated with an alleged undeclared nuclear accident in Russia in 2017.


title: Ruthenium

text: As the 78th most abundant element in Earth's crust, ruthenium is relatively rare, found in about 100 parts per trillion. This element is generally found in ores with the other platinum group metals in the Ural Mountains and in North and South America. Small but commercially important quantities are also found in pentlandite extracted from Sudbury, Ontario, Canada, and in pyroxenite deposits in South Africa. The native form of ruthenium is a very rare mineral (Ir replaces part of Ru in its structure). Ruthenium has a relatively high fission product yield in nuclear fission and given that its most long lived radioisotope has a half life of "only" around a year, there are often proposals to recover ruthenium in a new kind of nuclear reprocessing from spent fuel. An unusual ruthenium deposit can also be found at the natural nuclear fission reactor that was active in Oklo, Gabon some two billion years ago. Indeed, the isotope ratio of ruthenium found there was one of several ways used to confirm that a nuclear fission chain reaction had indeed occurred at that site in the geological past. Uranium is no longer mined at Oklo and there have never been serious attempts to recover any of the platinum group metals present there.


title: Ruthenium

text: Roughly 30 tonnes of ruthenium are mined each year with world reserves estimated at 5,000 tonnes. The composition of the mined platinum group metal (PGM) mixtures varies widely, depending on the geochemical formation. For example, the PGMs mined in South Africa contain on average 11% ruthenium while the PGMs mined in the former USSR contain only 2% (1992). Ruthenium, osmium, and iridium are considered the minor platinum group metals.


title: Ruthenium

text: Ruthenium, like the other platinum group metals, is obtained commercially as a by-product from nickel, and copper, and platinum metals ore processing. During electrorefining of copper and nickel, noble metals such as silver, gold, and the platinum group metals precipitate as "anode mud", the feedstock for the extraction. The metals are converted to ionized solutes by any of several methods, depending on the composition of the feedstock. One representative method is fusion with sodium peroxide followed by dissolution in aqua regia, and solution in a mixture of chlorine with hydrochloric acid. Osmium, ruthenium, rhodium, and iridium are insoluble in aqua regia and readily precipitate, leaving the other metals in solution. Rhodium is separated from the residue by treatment with molten sodium bisulfate. The insoluble residue, containing Ru, Os, and Ir is treated with sodium oxide, in which Ir is insoluble, producing dissolved Ru and Os salts. After oxidation to the volatile oxides, is separated from by precipitation of (NH)RuCl with ammonium chloride or by distillation or extraction with organic solvents of the volatile osmium tetroxide. Hydrogen is used to reduce ammonium ruthenium chloride yielding a powder. The product is reduced using hydrogen, yielding the metal as a powder or sponge metal that can be treated with powder metallurgy techniques or argon-arc welding.


title: Ruthenium

text: Ruthenium is contained in spent nuclear fuel both as a direct fission product and as a product of neutron absorption by long-lived fission product . After allowing the unstable isotopes of ruthenium to decay, chemical extraction could yield ruthenium for use or sale in all applications ruthenium is otherwise used for.


title: Ruthenium

text: Ruthenium can also be produced by deliberate nuclear transmutation from . Given the relatively long half life, high fission product yield and high chemical mobility in the environment, is among the most often proposed non-actinides for commercial scale nuclear transmutation. has a relatively big neutron cross section and given that Technetium has no stable isotopes, a sample would not run into the problem of neutron activation of stable isotopes. Significant amounts of are produced both by nuclear fission and nuclear medicine which makes ample use of which decays to . Exposing the target to strong enough neutron radiation will eventually yield appreciable quantities of Ruthenium which can be chemically separated and sold while consuming .


title: Ruthenium

text: The oxidation states of ruthenium range from 0 to +8, and −2. The properties of ruthenium and osmium compounds are often similar. The +2, +3, and +4 states are the most common. The most prevalent precursor is ruthenium trichloride, a red solid that is poorly defined chemically but versatile synthetically.


title: Ruthenium

text: Ruthenium can be oxidized to ruthenium(IV) oxide (RuO, oxidation state +4), which can, in turn, be oxidized by sodium metaperiodate to the volatile yellow tetrahedral ruthenium tetroxide, RuO, an aggressive, strong oxidizing agent with structure and properties analogous to osmium tetroxide. RuO is mostly used as an intermediate in the purification of ruthenium from ores and radiowastes.


title: Ruthenium

text: Dipotassium ruthenate (KRuO, +6) and potassium perruthenate (KRuO, +7) are also known. Unlike osmium tetroxide, ruthenium tetroxide is less stable, is strong enough as an oxidising agent to oxidise dilute hydrochloric acid and organic solvents like ethanol at room temperature, and is easily reduced to ruthenate () in aqueous alkaline solutions; it decomposes to form the dioxide above 100 °C. Unlike iron but like osmium, ruthenium does not form oxides in its lower +2 and +3 oxidation states. Ruthenium forms dichalcogenides, which are diamagnetic semiconductors crystallizing in the pyrite structure. Ruthenium sulfide (RuS) occurs naturally as the mineral laurite.


title: Ruthenium

text: Like iron, ruthenium does not readily form oxoanions and prefers to achieve high coordination numbers with hydroxide ions instead. Ruthenium tetroxide is reduced by cold dilute potassium hydroxide to form black potassium perruthenate, KRuO, with ruthenium in the +7 oxidation state. Potassium perruthenate can also be produced by oxidising potassium ruthenate, KRuO, with chlorine gas. The perruthenate ion is unstable and is reduced by water to form the orange ruthenate. Potassium ruthenate may be synthesized by reacting ruthenium metal with molten potassium hydroxide and potassium nitrate.


title: Ruthenium

text: The highest known ruthenium halide is the hexafluoride, a dark brown solid that melts at 54 °C. It hydrolyzes violently upon contact with water and easily disproportionates to form a mixture of lower ruthenium fluorides, releasing fluorine gas. Ruthenium pentafluoride is a tetrameric dark green solid that is also readily hydrolyzed, melting at 86.5 °C. The yellow ruthenium tetrafluoride is probably also polymeric and can be formed by reducing the pentafluoride with iodine. Among the binary compounds of ruthenium, these high oxidation states are known only in the oxides and fluorides.


title: Ruthenium

text: Ruthenium trichloride is a well-known compound, existing in a black α-form and a dark brown β-form: the trihydrate is red. Of the known trihalides, trifluoride is dark brown and decomposes above 650 °C, tribromide is dark-brown and decomposes above 400 °C, and triiodide is black. Of the dihalides, difluoride is not known, dichloride is brown, dibromide is black, and diiodide is blue. The only known oxyhalide is the pale green ruthenium(VI) oxyfluoride, RuOF.


title: Ruthenium

text: Ruthenium forms a variety of coordination complexes. Examples are the many pentaammine derivatives [Ru(NH)L] that often exist for both Ru(II) and Ru(III). Derivatives of bipyridine and terpyridine are numerous, best known being the luminescent tris(bipyridine)ruthenium(II) chloride.


title: Ruthenium

text: Ruthenium forms a wide range compounds with carbon-ruthenium bonds. Grubbs' catalyst is used for alkene metathesis. Ruthenocene is analogous to ferrocene structurally, but exhibits distinctive redox properties. The colorless liquid ruthenium pentacarbonyl converts in the absence of CO pressure to the dark red solid triruthenium dodecacarbonyl. Ruthenium trichloride reacts with carbon monoxide to give many derivatives including RuHCl(CO)(PPh) and Ru(CO)(PPh) (Roper's complex). Heating solutions of ruthenium trichloride in alcohols with triphenylphosphine gives tris(triphenylphosphine)ruthenium dichloride (RuCl(PPh)), which converts to the hydride complex chlorohydridotris(triphenylphosphine)ruthenium(II) (RuHCl(PPh)).


title: Ruthenium

text: Though naturally occurring platinum alloys containing all six platinum-group metals were used for a long time by pre-Columbian Americans and known as a material to European chemists from the mid-16th century, not until the mid-18th century was platinum identified as a pure element. That natural platinum contained palladium, rhodium, osmium and iridium was discovered in the first decade of the 19th century. Platinum in alluvial sands of Russian rivers gave access to raw material for use in plates and medals and for the minting of ruble coins, starting in 1828. Residues from platinum production for coinage were available in the Russian Empire, and therefore most of the research on them was done in Eastern Europe.


title: Ruthenium

text: It is possible that the Polish chemist Jędrzej Śniadecki isolated element 44 (which he called "vestium" after the asteroid Vesta discovered shortly before) from South American platinum ores in 1807. He published an announcement of his discovery in 1808. His work was never confirmed, however, and he later withdrew his claim of discovery.


title: Ruthenium

text: Jöns Berzelius and Gottfried Osann nearly discovered ruthenium in 1827. They examined residues that were left after dissolving crude platinum from the Ural Mountains in aqua regia. Berzelius did not find any unusual metals, but Osann thought he found three new metals, which he called pluranium, ruthenium, and polinium. This discrepancy led to a long-standing controversy between Berzelius and Osann about the composition of the residues. As Osann was not able to repeat his isolation of ruthenium, he eventually relinquished his claims. The name "ruthenium" was chosen by Osann because the analysed samples stemmed from the Ural Mountains in Russia. The name itself derives from the Latin word "Ruthenia"; this word was used at the time as the Latin name for Russia.


title: Ruthenium

text: In 1844, Karl Ernst Claus, a Russian scientist of Baltic German descent, showed that the compounds prepared by Gottfried Osann contained small amounts of ruthenium, which Claus had discovered the same year. Claus isolated ruthenium from the platinum residues of rouble production while he was working in Kazan University, Kazan, the same way its heavier congener osmium had been discovered four decades earlier. Claus showed that ruthenium oxide contained a new metal and obtained 6 grams of ruthenium from the part of crude platinum that is insoluble in aqua regia. Choosing the name for the new element, Claus stated: "I named the new body, in honour of my Motherland, ruthenium. I had every right to call it by this name because Mr. Osann relinquished his ruthenium and the word does not yet exist in chemistry." In doing so, Claus started a trend that continues to this day - naming an element after a country.


title: Ruthenium

text: Approximately 30.9 tonnes of ruthenium were consumed in 2016, 13.8 of them in electrical applications, 7.7 in catalysis, and 4.6 in electrochemistry.


title: Ruthenium

text: Because it hardens platinum and palladium alloys, ruthenium is used in electrical contacts, where a thin film is sufficient to achieve the desired durability. With its similar properties to and lower cost than rhodium, electric contacts are a major use of ruthenium. The ruthenium plate is applied to the electrical contact and electrode base metal by electroplating or sputtering.


title: Ruthenium

text: Ruthenium dioxide with lead and bismuth ruthenates are used in thick-film chip resistors. These two electronic applications account for 50% of the ruthenium consumption.


title: Ruthenium

text: Ruthenium is seldom alloyed with metals outside the platinum group, where small quantities improve some properties. The added corrosion resistance in titanium alloys led to the development of a special alloy with 0.1% ruthenium. Ruthenium is also used in some advanced high-temperature single-crystal superalloys, with applications that include the turbines in jet engines. Several nickel based superalloy compositions are described, such as EPM-102 (with 3% Ru), TMS-162 (with 6% Ru), TMS-138, and TMS-174, the latter two containing 6% rhenium. Fountain pen nibs are frequently tipped with ruthenium alloy. From 1944 onward, the Parker 51 fountain pen was fitted with the "RU" nib, a 14K gold nib tipped with 96.2% ruthenium and 3.8% iridium.


title: Ruthenium

text: Ruthenium is a component of mixed-metal oxide (MMO) anodes used for cathodic protection of underground and submerged structures, and for electrolytic cells for such processes as generating chlorine from salt water. The fluorescence of some ruthenium complexes is quenched by oxygen, finding use in optode sensors for oxygen. Ruthenium red, [(NH)Ru-O-Ru(NH)-O-Ru(NH)], is a biological stain used to stain polyanionic molecules such as pectin and nucleic acids for light microscopy and electron microscopy. The beta-decaying isotope 106 of ruthenium is used in radiotherapy of eye tumors, mainly malignant melanomas of the uvea. Ruthenium-centered complexes are being researched for possible anticancer properties. Compared with platinum complexes, those of ruthenium show greater resistance to hydrolysis and more selective action on tumors.


title: Ruthenium

text: Ruthenium tetroxide exposes latent fingerprints by reacting on contact with fatty oils or fats with sebaceous contaminants and producing brown/black ruthenium dioxide pigment.


title: Ruthenium

text: Electronics is the largest use of ruthenium. Ru metal is particularly nonvolatile, which is advantageous in microelectronic devices. Ru and its main oxide RuO have comparable electrical resistivities. Copper can be directly electroplated onto ruthenium, particular applications include barrier layers, transistor gates, and interconnects. Ru films can be deposited by chemical vapor deposition using volatile complexes such as ruthenium tetroxide and the organoruthenium compound (cyclohexadiene)Ru(CO).


title: Ruthenium

text: Many ruthenium-containing compounds exhibit useful catalytic properties. The catalysts are conveniently divided into those that are soluble in the reaction medium, homogeneous catalysts, and those that are not, which are called heterogeneous catalysts.


title: Ruthenium

text: Solutions containing ruthenium trichloride are highly active for olefin metathesis. Such catalysts are used commercially for the production of polynorbornene for example. Well defined ruthenium carbene and alkylidene complexes show similar reactivity but are only used on small-scale. The Grubbs' catalysts for example have been employed in the preparation of drugs and advanced materials.


title: Ruthenium

text: Ruthenium complexes are highly active catalysts for transfer hydrogenations (sometimes referred to as "borrowing hydrogen" reactions). Chiral ruthenium complexes, introduced by Ryoji Noyori, are employed for the enantioselective hydrogenation of ketones, aldehydes, and imines. A typical catalyst is (cymene)Ru(S,S-TsDPEN):


title: Ruthenium

text: A Nobel Prize in Chemistry was awarded in 2001 to Ryōji Noyori for contributions to the field of asymmetric hydrogenation.


title: Ruthenium

text: Some ruthenium complexes absorb light throughout the visible spectrum and are being actively researched for solar energy technologies. For example, ruthenium-based compounds have been used for light absorption in dye-sensitized solar cells, a promising new low-cost solar cell system.


title: Ruthenium

text: Many ruthenium-based oxides show very unusual properties, such as a quantum critical point behavior, exotic superconductivity (in its strontium ruthenate form), and high-temperature ferromagnetism.


title: Ruthenium

text: Little is known about the health effects of ruthenium and it is relatively rare for people to encounter ruthenium compounds. Metallic ruthenium is inert (is not chemically reactive). Some compounds such as ruthenium oxide (RuO) are highly toxic and volatile.


title: Greater Vancouver

text: Greater Vancouver, also known as Metro Vancouver, is the metropolitan area with its major urban centre being the city of Vancouver, British Columbia, Canada. The term "Greater Vancouver" is roughly coterminous with the geographic area governed by the Metro Vancouver Regional District, though it predates the 1966 creation of the regional district. It is often used to include areas beyond the boundaries of the regional district but does not generally include wilderness and agricultural areas within that regional district.