title: History of the kilt

text: For battle, it was customary to take off the kilt beforehand and set it aside, the Highland charge being made wearing only the or war shirt, a knee-length shirt of leather, linen, or canvas, heavily pleated and sometimes quilted as protection.


title: History of the kilt

text: The exact age of the great kilt is still under debate. Earlier carvings or illustrations prior to the 16th century appearing to show the kilt may show the . The earliest written source that definitely describes the belted plaid or great kilt comes from 1594. The great kilt is mostly associated with the Scottish Highlands, but was also used in poor Lowlands rural areas. Widespread use of this type of kilt continued into the 19th century, and some still wear it today (kiltmakers who still supply great kilts offer them primarily as highly formal attire – equivalent to white-tie evening wear – typically paired with a Sheriffmuir doublet and a ruffled jabot).


title: History of the kilt

text: Sometime in the late 17th or early 18th century the small kilt (, anglicised as "filibeg" or "philabeg"), using a single width of cloth worn hanging down below the belt came into use, becoming popular throughout the Highlands and northern Lowlands by 1746, although the great kilt or belted plaid continued to be worn. The small kilt is a development from the great kilt, being essentially its bottom half.


title: History of the kilt

text: A letter written by Ivan Baillie in 1768 and published in the "Edinburgh Magazine" in March 1785 states that the garment people would recognize as a kilt today was invented in the 1720s by Thomas Rawlinson, a Quaker from Lancashire. After the Jacobite campaign of 1715, the government opened the Highlands to outside exploitation, and Rawlinson went into partnership with Ian MacDonnell, chief of the MacDonnells of Glengarry to manufacture charcoal from the forests near Inverness and smelt iron ore there. The belted plaid worn by the Highlanders he employed was too "cumbrous and unwieldy" for this work, so, together with the tailor of the regiment stationed at Inverness, Rawlinson produced a kilt which consisted of the lower half of the belted plaid worn as a "distinct garment with pleats already sewn". He wore it himself, as did his business partner, whose clansmen then followed suit.


title: History of the kilt

text: It has been suggested that there is evidence of Highlanders wearing only the bottom part of the belted plaid before this, possibly as early as the 1690s, but Rawlinson's is the earliest documented example with sewn-in pleats, a distinctive feature of the kilt worn today.


title: History of the kilt

text: The tailored kilt was adopted by the Highland regiments of the British Army, and the military kilt and its formalised accessories passed into civilian usage during the early 19th century and have remained popular ever since.


title: History of the kilt

text: The earliest extant example of a tailored kilt is from 1792 (currently in the possession of the Scottish Tartans Authority).


title: History of the kilt

text: A characteristic of the Highland clan system was that clansmen felt loyalty only to God, their monarch, and their Chief. The Jacobite risings demonstrated the dangers to central government of such warrior Highland clans, and as part of a series of measures the government of King George II imposed the "Dress Act" in 1746, outlawing all items of Highland dress including kilts (although an exception was made for the Highland Regiments) with the intent of suppressing highland culture. The penalties were severe; six months' imprisonment for the first offense and seven years' transportation for the second. The ban remained in effect for 35 years.


title: History of the kilt

text: Thus, with the exception of the Army and those who served in it, the kilt went out of use in the Scottish Highlands, but during those years it became fashionable for Scottish romantics to wear kilts as a form of protest against the ban. This was an age that romanticized "primitive" peoples, which is how Highlanders were viewed. Most Lowlanders had viewed Highlanders with fear before 1745, but many identified with them after their power was broken. The kilt, along with other features of Gaelic culture, had become identified with Jacobitism, and now that this had ceased to be a real danger it was viewed with romantic nostalgia.


title: History of the kilt

text: Once the ban was lifted in 1782, Highland landowners set up Highland Societies with aims including "Improvements" (which others would call the Highland clearances) and promoting "the general use of the ancient Highland dress". The Celtic Society of Edinburgh, chaired by Walter Scott, encouraged lowlanders to join this antiquarian enthusiasm.


title: History of the kilt

text: The kilt became identified with the whole of Scotland with the pageantry of the visit of King George IV to Scotland in 1822, even though 9 out of 10 Scots now lived in the Lowlands. Scott and the Highland societies organised a "gathering of the Gael" and established entirely new Scottish traditions, including Lowlanders wearing a stylised version of the traditional garment of the Highlanders. At this time many other traditions such as clan identification by tartan were developed (prior to this, tartans were identified with regions, not specific clans).


title: History of the kilt

text: After that point the kilt gathered momentum as an emblem of Scottish culture as identified by antiquarians, romantics, and others, who spent much effort praising the "ancient" and natural qualities of the kilt. King George IV had appeared in a spectacular kilt, and his successor Queen Victoria dressed her boys in the kilt, widening its appeal. The kilt became part of the Scottish national identity and the wider Celtic identity.


title: History of the kilt

text: From 1624 the Independent Companies of Highlanders had worn kilts as government troops, and with their formation into the Highland regiment in 1739 their great kilt uniform was standardised with a new dark tartan.


title: History of the kilt

text: Many Jacobite rebels adopted kilts as an informal uniform, with even their English supporters wearing tartan items during the Jacobite rising of 1745. In the aftermath of that rebellion the Government decided to form more Highland regiments for the army in order to direct the energies of Gaels, that "hardy and intrepid race of men". In doing so they formed effective new army regiments to send to fight in India, North America, and other locations while lowering the possibility of rebellion at home. Army uniforms were exempt from the ban on wearing kilts in the "Dress Act", and as a means of identification the regiments were given different tartans. These regiments opted for the modern kilts for dress uniforms, and while the great kilt remained as undress uniform this was phased out by the early 19th century.


title: History of the kilt

text: Many Scottish units wore the kilt in combat during the First World War. In particular, the ferocious tactics of the Black Watch led to their acquiring the nickname "Ladies from Hell" from the German troops that faced them in the trenches. The Highland regiments of the Commonwealth armies entered the Second World War wearing the kilt, but it was rapidly recognized as impractical for modern warfare, and in the first year of the war was officially banned as combat dress. Nonetheless, individual exceptions continued, and it is believed the kilt was last widely worn in action at the evacuation of Dunkirk in May 1940. However, on D-Day, June 1944, Lord Lovat, commander of 1 Special Service Brigade, was accompanied by his personal piper Bill Millin, who wore a kilt – and played the bagpipes – while German bullets whizzed around him.


title: History of the kilt

text: The kerns of Gaelic Ireland wore the long léine, or "saffron shirt" (often misinterpreted as a kilt in depictions) may have had connections with the predecessor of the modern kilt. This tradition has been continued in the pipe bands of the Republic of Ireland's defence forces.


title: History of the kilt

text: The kilt is utilized in the modern full-dress uniforms for multiple active Scottish regiments of the British Army who have some affiliation with Scotland. This includes the Royal Regiment of Scotland, Scots Guards, Royal Scots Dragoon Guards, and many other units.


title: Universal motor

text: The universal motor is a type of electric motor that can operate on either AC or DC power and uses an electromagnet as its stator to create its magnetic field. It is a commutated series-wound motor where the stator's field coils are connected in series with the rotor windings through a commutator. It is often referred to as an AC series motor. The universal motor is very similar to a DC series motor in construction, but is modified slightly to allow the motor to operate properly on AC power. This type of electric motor can operate well on AC because the current in both the field coils and the armature (and the resultant magnetic fields) will alternate (reverse polarity) synchronously with the supply. Hence the resulting mechanical force will occur in a consistent direction of rotation, independent of the direction of applied voltage, but determined by the commutator and polarity of the field coils.


title: Universal motor

text: Universal motors have high starting torque, can run at high speed, and are lightweight and compact. They are commonly used in portable power tools and equipment, as well as many household appliances. They're also relatively easy to control, electromechanically using tapped coils, or electronically. However, the commutator has brushes that wear, so they are much less often used for equipment that is in continuous use. In addition, partly because of the commutator, universal motors are typically very noisy, both acoustically and electromagnetically.


title: Universal motor

text: If an ordinary series wound DC motor were connected to an AC supply, it would run very poorly. The universal motor is modified in several ways to allow for proper AC supply operation. There is a compensating winding typically added, along with laminated pole pieces, as opposed to the solid pole pieces found in DC motors. A universal motor's armature typically has far more coils and plates than a DC motor, and hence fewer windings per coil. This reduces the inductance.


title: Universal motor

text: Even when used with AC power these types of motors are able to run at a rotation frequency well above that of the mains supply, and because most electric motor properties improve with speed, this means they can be lightweight and powerful. However, universal motors are usually relatively inefficient: around 30% for smaller motors and up to 70–75% for larger ones.


title: Universal motor

text: Series wound electric motors respond to increased load by slowing down; the current increases and the torque rises in proportion to the square of the current since the same current flows in both the armature and the field windings. If the motor is stalled, the current is limited only by the total resistance of the windings and the torque can be very high, and there is a danger of the windings becoming overheated. The counter-EMF aids the armature resistance to limit the current through the armature. When power is first applied to a motor, the armature does not rotate. At that instant, the counter-EMF is zero and the only factor limiting the armature current is the armature resistance. Usually the armature resistance of a motor is low; therefore the current through the armature would be very large when the power is applied. Therefore the need can arise for an additional resistance in series with the armature to limit the current until the motor rotation can build up the counter-EMF. As the motor rotation builds up, the resistance is gradually cut out. The speed-torque characteristic is an almost perfectly straight line between the stall torque and the no-load speed. This suits large inertial loads as the speed will drop until the motor slowly starts to rotate and these motors have a very high stalling torque.


title: Universal motor

text: As the speed increases, the inductance of the rotor means that the ideal commutating point changes. Small motors typically have fixed commutation. While some larger universal motors have rotatable commutation, this is rare. Instead larger universal motors often have "compensation windings" in series with the motor, or sometimes inductively coupled, and placed at ninety electrical degrees to the main field axis. These reduce the reactance of the armature, and improve the commutation.


title: Universal motor

text: One useful property of having the field windings in series with the armature winding is that as the speed increases the counter EMF naturally reduces the voltage across, and current through the field windings, giving field weakening at high speeds. This means that the motor has no theoretical maximum speed for any particular applied voltage. Universal motors can be and are generally run at high speeds, 4000–16000RPM, and can go over 20,000RPM. By way of contrast, AC synchronous and squirrel cage induction motors cannot turn a shaft faster than allowed by the power line frequency. In countries with 60Hz AC supply, this speed is limited to 3600RPM.


title: Universal motor

text: Motor damage may occur from over-speeding (running at a rotational speed in excess of design limits) if the unit is operated with no significant mechanical load. On larger motors, sudden loss of load is to be avoided, and the possibility of such an occurrence is incorporated into the motor's protection and control schemes. In some smaller applications, a fan blade attached to the shaft often acts as an artificial load to limit the motor speed to a safe level, as well as a means to circulate cooling airflow over the armature and field windings. If there were no mechanical limits placed on a universal motor it could theoretically speed out of control in the same way any series-wound DC motor can.


title: Universal motor

text: An advantage of the universal motor is that AC supplies may be used on motors which have some characteristics more common in DC motors, specifically high starting torque and very compact design if high running speeds are used.


title: Universal motor

text: A negative aspect is the maintenance and short life problems caused by the commutator, as well as electromagnetic interference (EMI) issues due to any sparking. Because of the relatively high maintenance commutator brushes, universal motors are best-suited for devices such as food mixers and power tools which are used only intermittently, and often have high starting-torque demands.


title: Universal motor

text: Another negative aspect is that these motors may only be used where mostly-clean air is present at all times. Due to the dramatically increased risk of overheating, totally-enclosed fan cooled universal motors would be impractical, though some have been made. Such a motor would need a large fan to circulate enough air, decreasing efficiency since the motor must use more energy to cool itself. The impracticality comes from the resulting size, weight, and thermal management issues which open motors have none of.


title: Universal motor

text: Continuous speed control of a universal motor running on AC is easily obtained by use of a thyristor circuit, while multiple taps on the field coil provide (imprecise) stepped speed control. Household blenders that advertise many speeds frequently combine a field coil with several taps and a diode that can be inserted in series with the motor (causing the motor to run on half-wave rectified AC).


title: Universal motor

text: Universal motors are series wound. Shunt winding was used experimentally, in the late 19th century, but was impractical owing to problems with commutation. Various schemes of embedded resistance, inductance and antiphase cross-coupling were attempted to reduce this. Universal motors, including shunt wound, were favoured as AC motors at this time as they were self-starting. When self-starting induction motors and automatic starters became available, these replaced the larger universal motors (above 1 hp) and the shunt wound.


title: Universal motor

text: In the past, repulsion-start wound-rotor motors provided high starting torque, but with added complexity. Their rotors were similar to those of universal motors, but their brushes were connected only to each other. Transformer action induced current into the rotor. Brush position relative to field poles meant that starting torque was developed by rotor repulsion from the field poles. A centrifugal mechanism, when close to running speed, connected all commutator bars together to create the equivalent of a squirrel-cage rotor. As well, when close to approximately 80 per cent of its run speed, these motors can run as induction motors.


title: Universal motor

text: Operating at normal power line frequencies, universal motors are often found in a range less than . Their high speed makes them useful for appliances such as blenders, vacuum cleaners, and hair dryers where high speed and light weight are desirable. They are also commonly used in portable power tools, such as drills, sanders, circular and jig saws, where the motor's characteristics work well. An added benefit for power tools used by welders is that classic engine-driven welding machines may be a pure DC generator, and their auxiliary power receptacles will still be DC, even though a typical NEMA 5-15 household configuration. The DC power is fine for typical jobsite incandescent lighting and the universal motors in drills and grinders. Many vacuum cleaner and weed trimmer motors exceed , while many Dremel and similar miniature grinders exceed .


title: Universal motor

text: Universal motors also lend themselves to electronic speed control and, as such, were an ideal choice for domestic washing machines. The motor can be used to agitate the drum (both forwards and in reverse) by switching the field winding with respect to the armature. The motor can also be run up to the high speeds required for the spin cycle. Nowadays, variable-frequency drive motors are more commonly used instead.


title: Universal motor

text: Universal motors also formed the basis of the traditional railway traction motor in electric railways. In this application, the use of AC to power a motor originally designed to run on DC would lead to efficiency losses due to eddy current heating of their magnetic components, particularly the motor field pole-pieces that, for DC, would have used solid (un-laminated) iron. Although the heating effects are reduced by using laminated pole-pieces, as used for the cores of transformers and by the use of laminations of high permeability electrical steel, one solution available at the start of the 20th century was for the motors to be operated from very low frequency AC supplies, with operation being common.


title: Universal motor

text: Starters of combustion engines are usually universal motors, with the advantage of being small and having high torque at low speed. Some starters have permanent magnets, others have 1 out of the 4 poles wound with a shunt coil rather than series wound coils.


title: Monte Kiffin

text: Monte George Kiffin (born February 29, 1940) is an American football coach. He is currently a player personnel analyst at Ole Miss for his son, Lane Kiffin. He is widely considered to be one of the preeminent defensive coordinators in modern football, as well as one of the greatest defensive coordinators in NFL history. Father of the widely imitated "Tampa 2" defense, Kiffin's concepts are among the most influential in modern college and pro football.


title: Monte Kiffin

text: Before taking the role as Dallas Cowboys defensive coordinator, Kiffin served as assistant head coach for the University of Southern California where his son Lane Kiffin was named head coach on January 12, 2010, and before that he served under his son as the defensive coordinator at the University of Tennessee. Possibly due to the mounting pressure on his son's poor coaching records, on November 29, 2012, Kiffin resigned from his position to pursue other opportunities in the NFL. He previously served 26 years as an NFL assistant coach, including 13 years as defensive coordinator for the Tampa Bay Buccaneers, with whom he won Super Bowl XXXVII. His defensive units have finished ranked in the top 10 in points allowed and yards allowed 10 times during that period, an NFL record.


title: Monte Kiffin

text: Kiffin was paid about $1.2 million per year by Tennessee. He earned a reported $2 million annual salary from the Buccaneers and has turned down several NFL head coaching jobs during his career. To this day, Kiffin's only head coaching job was at North Carolina State University from 1980 to 1982.


title: Monte Kiffin

text: A native of Lexington, Nebraska, Kiffin was an offensive and defensive tackle at the University of Nebraska–Lincoln from 1959 to 1963. In 1966, he played 8 games with the Toronto Rifles of the Continental Football League and also was a member of the Brooklyn Dodgers of the same league. After a brief stint as a defensive end for the Winnipeg Blue Bombers, Kiffin returned to Nebraska as a defensive coach. Kiffin was a defensive assistant at Nebraska under legendary coach, Bob Devaney. He coached the defenses of Nebraska's 1970 and 1971 back-to-back undefeated national champion teams under coordinator Lance Van Zant. After then offensive coordinator Tom Osborne was selected as the head coach in 1973, Monte was elevated to the defensive coordinator in 1974. In 1977, he moved to the University of Arkansas, and then in 1980, he got his one and only head coaching job at North Carolina State University.


title: Monte Kiffin

text: After his time at NC State, Kiffin began a series of short stints in the NFL for the Green Bay Packers, Buffalo Bills, Minnesota Vikings (twice), New York Jets, and New Orleans Saints. In 1996, he became the defensive coordinator for the Buccaneers.


title: Monte Kiffin

text: After Tony Dungy was dismissed by the Buccaneer front office following the 2001 season, Kiffin was persuaded by incoming head coach Jon Gruden to remain in Tampa and continue to run his defense. Kiffin had been interviewed for a head coaching position with the San Francisco 49ers. With the seamless transition on defense allowing the new coaching staff to focus intently on a more potent offensive philosophy, the result was an immediate balance between offense and defense that carried the Buccaneers to the organization's first championship in Super Bowl XXXVII on January 26, 2003 in San Diego, California.


title: Monte Kiffin

text: Controversy has surrounded Kiffin's departure from Tampa Bay. After Lane Kiffin signed with Tennessee, Tampa's typically stout defense underperformed. The Bucs lost their final four games of the 2008 season, ending up 9–7, and missed the playoffs. Reports stated that Gruden refused to allow Kiffin to announce his departure to Tennessee mid-season. Allegations were made that Kiffin refused to participate in normal coaching meetings. Neither Kiffin nor Jon Gruden have openly discussed these events.


title: Monte Kiffin

text: Monte joined the University of Southern California coaching staff as defensive coordinator, after his son Lane Kiffin became the head coach.


title: Monte Kiffin

text: On January 11, 2013, following the 2012-13 NFL regular season, Kiffin was hired as defensive coordinator for the Dallas Cowboys. Kiffin was demoted on January 28, 2014 in favor of defensive line coach Rod Marinelli. At the end of the 2014 season Kiffin's contract was allowed to lapse, and it was not renewed by the Cowboys.


title: Monte Kiffin

text: Monte Kiffin is the mastermind behind the Tampa 2 scheme, which is a slight modification of Tony Dungy's Cover 2. His defensive philosophy has several hallmarks.


title: Monte Kiffin

text: Kiffin's sons are both football coaches. Elder son, Lane Kiffin, played football at Fresno State before entering coaching: becoming the head coach of the Oakland Raiders, Tennessee Volunteers, USC Trojans, and Florida Atlantic Owls, the offensive coordinator and quarterbacks coach for the Alabama Crimson Tide and is currently the head coach at the University of Mississippi. Younger son, Chris Kiffin, played football at Colorado State and is now the defensive line coach for the Cleveland Browns.


title: MicroLED

text: microLED, also known as micro-LED, mLED or µLED, first invented in 2000 by the research group of Hongxing Jiang and Jingyu Lin of Texas Tech University while they were at Kansas State University, is an emerging flat-panel display technology. microLED displays consist of arrays of microscopic LEDs forming the individual pixel elements. The first high-resolution and video-capable InGaN microLED microdisplay in VGA format was realized in 2009 by Hongxing Jiang and Jingyu Lin and their colleagues at Texas Tech University and III-N Technology, Inc. via active driving of microLED array by a complementary metal-oxide semiconductor (CMOS) IC. Compared to widespread LCD technology, microLED displays offer better contrast, response times, and energy efficiency.


title: MicroLED

text: MicroLED offers greatly reduced energy requirements when compared to conventional LCD displays while also offering pixel-level light control and a high contrast ratio. The inorganic nature of microLEDs gives them a longer lifetime advantage over OLEDs and allows them to display brighter images with minimal risk of screen burn-in. The sub-nanosecond response time of µLED has a huge advantage over other display technologies for 3D/AR/VR displays since these devices need more images, more pixels per image, more frames per second and fast response.


title: MicroLED

text: , microLED displays have not been mass-produced, although Sony, Samsung, and Konka sell microLED video walls. LG, Tianma, PlayNitride, TCL/CSoT, Jasper Display, Jade Bird Display, Plessey Semiconductors Ltd, and Ostendo Technologies, Inc. have demonstrated prototypes. Sony already sells microLED displays as a replacement for conventional cinema screens. BOE, Epistar, and Leyard have plans for microLED mass production. MicroLED can be made flexible and transparent, just like OLEDs.


title: MicroLED

text: Inorganic semiconductor microLED (µLED) technology was first invented in 2000 by the research group of Hongxing Jiang and Jingyu Lin of Texas Tech University while they were at Kansas State University. Following their first report of electrical injection microLEDs based on indium gallium nitride (InGaN) semiconductors, several groups have quickly engaged in pursuing this concept. Many related potential applications have been identified. Various on-chip connection schemes of microLED pixel arrays have been employed by AC LED Lighting, LLC (a company funded by Hongxing Jiang and Jingyu Lin) allowing for the development of single-chip high voltage DC/AC-LEDs to address the compatibility issue between the high voltage electrical infrastructure and low voltage operation nature of LEDs and high brightness self-emissive microdisplays.


title: MicroLED

text: The microLED array has also been explored as a light source for optogenetics applications and for visible light communications.


title: MicroLED

text: Early InGaN based microLED arrays and microdisplays were primarily passively driven. The first actively driven video-capable self-emissive InGaN microLED microdisplay in VGA format ( pixels, each 12µm in size with 15µm between them) possessing low voltage requirements was patented and realized in 2009 by Hongxing Jiang and Jingyu Lin and their colleagues at III-N Technology, Inc. (a company funded by Hongxing Jiang and Jingyu Lin) and Texas Tech University, via heterogeneous integration between microLED array and CMOS integrated circuit (IC) and the work was also published in the following years.


title: MicroLED

text: The first microLED products were demonstrated by Sony in 2012. These displays, however, were very expensive.


title: MicroLED

text: There are several methods to manufacture microLED displays. The flip-chip method manufactures the LED on a conventional sapphire substrate, while the transistor array and solder bumps are deposited on silicon wafers using conventional manufacturing and metallization processes. Mass transfer is used to pick and place several thousand LEDs from one wafer to another at the same time, and the LEDs are bonded to the silicon substrate using reflow ovens. The flip-chip method is used for micro displays used on virtual reality headsets. The drawbacks include cost, limited pixel size, limited placement accuracy, and the need for cooling to prevent the display from warping and breaking due to thermal mismatch between the LEDs and the silicon. Also, current microLED displays are less efficient than comparable OLED displays. Another microLED manufacturing method involves bonding the LEDs to an IC layer on a silicon substrate and then removing the LED bonding material using conventional semiconductor manufacturing techniques. The current bottleneck in the manufacturing process is the need to individually test every LED and replace faulty ones using an excimer laser lift-off apparatus, which uses a laser to weaken the bond between the LED and its substrate. Faulty LED replacement must be performed using high accuracy pick-and-place machines and the test and repair process takes several hours. The mass transfer process alone can take 18 days, for a smartphone screen with a glass substrate. Special LED manufacturing techniques can be used to increase yield and reduce the amount of faulty LEDs that need to be replaced. Each LED can be as small as 5µm across. LED epitaxy techniques need to be improved to increase LED yields.


title: MicroLED

text: Excimer lasers are used for several steps: laser lift-off to separate LEDs from their sapphire substrate and to remove faulty LEDs, for manufacturing the LTPS-TFT backplane, and for laser cutting of the finished LEDs. Special mass transfer techniques using elastomer stamps are also being researched. Other companies are exploring the possibility of packaging 3 LEDs: one red, one green and one blue LED into a single package to reduce mass transfer costs.


title: MicroLED

text: Quantum dots are being researched as a way to shrink the size of microLED pixels, while other companies are exploring the use of phosphors and quantum dots to eliminate the need for different-colored LEDs. Sensors can be embedded in microLED displays.


title: MicroLED

text: Over 130 companies are involved in microLED research and development. MicroLED light panels are also being made, and are an alternative to conventional OLED and LED light panels.


title: MicroLED

text: Digital pulse-width modulation is well-suited to driving microLED displays. MicroLEDs experience a color shift as the current magnitude changes. Analog schemes change current to change brightness. With a digital pulse, only one current value is used for the on state. Thus, there is no color shift that occurs as brightness changes.


title: MicroLED

text: Current microLED display offerings by Samsung and Sony consist of "cabinets" that can be tiled to create a large display of any size, with the display's resolution increasing with size. They also contain mechanisms to protect the display against water and dust. Each cabinet is diagonally with a resolution of .


title: MicroLED

text: microLEDs have innate potential performance advantages over LCD displays, including higher brightness, lower latency, higher contrast ratio, greater color saturation, intrinsic self-illumination, and better efficiency. As of 2016, technological and production barriers have prevented commercialization.


title: MicroLED

text: As of 2016, a number of different technologies were under active research for the assembling of individual LED pixels on a substrate. These include chip bonding of microLED chips onto a substrate (considered to have potential for large displays), wafer production methods using etching to produce an LED array followed by bonding to an IC, and wafer production methods using an intermediate temporary thin film to transfer the LED array to a substrate.


title: MicroLED

text: Glo and Jasper Display Corporation demonstrated the world's first RGB microLED microdisplay, measuring diagonally, at SID Display Week 2017. Glo transferred their microLEDs to the Jasper Display backplane.


title: MicroLED

text: Sony launched a "Crystal LED Display" in 2012 with resolution, as a demonstration product. Sony announced its CLEDIS (Crystal LED Integrated Structure) brand which used surface mounted LEDs for large display production. As of August 2019, Sony offers CLEDIS in , and displays. On 12 September 2019, Sony announced Crystal LED availability to consumers ranging from 1080p to 16K displays.


title: MicroLED

text: Samsung demonstrated a microLED display called The Wall at CES 2018. In July 2018, Samsung announced plans on bringing a 4K microLED TV to consumer market in 2019. At CES 2019, Samsung demonstrated a 4K microLED display and 6K microLED display. On June 12 at InfoComm 2019, Samsung announced the global launch of The Wall Luxury microLED display configurable from in 2K to in 8K. On October 4, 2019, Samsung announced that The Wall Luxury microLED display shipments had begun.


title: MicroLED

text: In March 2018, Bloomberg reported Apple to have about 300 engineers devoted to in-house development of microLED screens. At IFA 2018 in August, LG Display demonstrated a microLED display.


title: MicroLED

text: At SID's Display Week 2019 in May, Tianma and PlayNitride demonstrated their co-developed microLED display with over 60% transparency. China Star Optoelectronics Technology (CSoT) demonstrated a transparent microLED display with around 45% transparency, also co-developed with PlayNitride. Plessey Semiconductors Ltd demonstrated a monolithic monochrome blue GaN-on-silicon wafer bonded to a Jasper Display CMOS backplane active-matrix microLED display with an 8μm pixel pitch.


title: MicroLED

text: At SID's Display Week 2019 in May, Jade Bird Display demonstrated their 720p and 1080p microLED microdisplays with 5μm and 2.5μm pitch respectively, achieving luminance in the millions of candelas per square metre. In 2021, Jade Bird Display and Vuzix have entered a Joint manufacturing agreement for making microLED based projectors for smart glasses and augmented reality glasses


title: MicroLED

text: At Touch Taiwan 2019 on September 4, 2019, AU Optronics demonstrated a microLED display and indicated that microLED was 12 years from mass commercialization. At IFA 2019 on September 13, 2019, TCL Corporation demonstrated their Cinema Wall featuring a 4K microLED display with maximum brightness of 1,500cd/m and contrast ratio produced by their subsidiary China Star Optoelectronics Technology (CSoT).


title: Mary Karr

text: Mary Karr (born January 16, 1955) is an American poet, essayist and memoirist from East Texas. She is widely noted for her 1995 bestselling memoir "The Liars' Club". Karr is the Jesse Truesdell Peck Professor of English Literature at Syracuse University.


title: Mary Karr

text: Karr's memoir "The Liars' Club", published in 1995, was a "New York Times" bestseller for over a year, and was named one of the year's best books. It explores her deeply troubled childhood, most of which was spent in a gritty industrial section of Southeast Texas in the 1960s. Karr was encouraged to write her personal history by her friend Tobias Wolff, but has said she only took up the project when her marriage fell apart.


title: Mary Karr

text: She followed the book with a second memoir, "Cherry" (2000), about her late adolescence and early womanhood.


title: Mary Karr

text: A third memoir, "Lit: A Memoir", which she says details "my journey from blackbelt sinner and lifelong agnostic to unlikely Catholic," came out in November 2009. The memoir describes Karr's time as an alcoholic and the salvation she found in her conversion to Catholicism. She describes herself as a cafeteria Catholic.


title: Mary Karr

text: Karr won a 1989 Whiting Award for her poetry. She was a Guggenheim Fellow in poetry in 2005 and has won Pushcart prizes for both her poetry and essays. Karr has published five volumes of poetry: "Abacus" (Wesleyan University Press, CT, 1987, in its New Poets series), "The Devil's Tour" (New Directions NY, 1993, an original TPB), "Viper Rum" (New Directions NY, 1998, an original TPB), "Sinners Welcome" (HarperCollins, NY, 2006), and "Tropic of Squalor" (HarperCollins, NY, 2018). Her poems have appeared in major literary magazines such as "Poetry", "The New Yorker", and "The Atlantic Monthly".


title: Mary Karr

text: Karr's Pushcart Award-winning essay, "Against Decoration", was originally published in the quarterly review "Parnassus" (1991) and later reprinted in "Viper Rum". In "Against Decoration", Karr took a stand in favor of content over poetic style. She argued emotions need to be directly expressed and clarity should be a watch-word: characters are too obscure, the presented physical world is often "foggy" (that is imprecise), references are "showy" (both non-germane and overused), metaphors overshadow expected meaning, and techniques of language (polysyllables, archaic words, intricate syntax, "yards of adjectives") only "slow a reader's understanding".


title: Mary Karr

text: Another essay, "Facing Altars: Poetry and Prayer", was originally published in "Poetry" (2005). Karr tells of moving from agnostic alcoholic to baptized Catholic of the decidedly "cafeteria" kind, yet one who prays twice daily with loud fervor from her "foxhole". In this essay, Karr argues that poetry and prayer arise from the same sources within us.


title: Mary Karr

text: In May 2015, Karr served as the commencement speaker at the 161 commencement for Syracuse University.


title: Mary Karr

text: Karr was born in Groves, Texas, on January 16, 1955, and lived there until she moved to Los Angeles in 1972. That same year, Karr started at Macalester College in St. Paul, Minnesota, where she studied for two years and met poet Etheridge Knight, one of her first mentors. Karr later attended and graduated from Goddard College, where she studied with the poets Robert Hass and Stephen Dobyns.


title: Mary Karr

text: Karr was married to poet Michael Milburn for 13 years. At some point, she had a relationship with author David Foster Wallace. Karr spoke out about Wallace's abusive behaviour, which included years of stalking, throwing a coffee table at her, and harassing her five-year-old son.


title: Mary Karr

text: Although a convert to Catholicism, Karr supports views that are at odds with Catholic Church teaching: on abortion she is pro-choice, and she has spoken in favor of women's ordination to the priesthood. Karr has described herself as a feminist since age 12.


title: Green curry

text: The name "green" curry derives from the color of the dish, which comes from green chillies. The "sweet" in the Thai name ("wan" means 'sweet') refers to the particular color green itself and not to the taste of the curry. As this is a Thai curry based on coconut milk and fresh green chillies, the color comes out creamy mild green or, as this color is called in Thai, "sweet green".


title: Green curry

text: Its ingredients are not exactly fixed. The curry is not necessarily sweeter than other Thai curries but, although the spiciness varies, it tends to be more pungent than the milder red curries. Green curry evolved during the reign of King Rama VI or Rama VII, between the years 1908-1926.


title: Green curry

text: Apart from a main protein, traditionally fish, fish balls, or meat, the other ingredients for the dish consist of coconut milk, green curry paste, palm sugar, and fish sauce. Thai eggplant (aubergine), pea aubergine, basil leaves or other green or whitish vegetables and even fruit are often included.


title: Green curry

text: The consistency of its sauce varies with the amount of coconut milk used. Green curry paste is traditionally made by pounding in a mortar green chillies, shallots, garlic, galangal, lemongrass, kaffir lime leaves, cilantro roots (coriander), and cumin seeds, white peppercorns, shrimp paste and salt.


title: Green curry

text: The paste is fried in split coconut cream until the oil is expressed to release the aromas in the paste. Once the curry paste is cooked, more coconut milk and the remaining ingredients are added along with a pinch of palm sugar and fish sauce. Finally, as garnishes, Thai basil, fresh kaffir lime leaves, sliced "phrik chi faa" (common name means "sky-pointing chilies" which refers to large mild chilies such as Cayenne pepper) are often used. For a more robust green curry, such as with seafood, julienned krachai (fingerroot/wild ginger/Chinese keys), white turmeric, and holy basil can be used as garnishes.


title: Green curry

text: Green curry is typically eaten with rice as part of a wider range of dishes in a meal, or with round rice noodles known as "khanom chin" as a single dish.


title: Port of Singapore

text: The Port of Singapore refers to the collective facilities and terminals that conduct maritime trade and handles Singapore's harbours and shipping. It has been ranked as the top maritime capital of the world since 2015. Currently the world's second-busiest port in terms of total shipping tonnage, it also transships a third of the world's shipping containers, half of the world's annual supply of crude oil, and is the world's busiest transshipment port. It had also been the busiest port in terms of total cargo tonnage handled until 2005 when it was surpassed by the Port of Shanghai.


title: Port of Singapore

text: Because of its strategic location, Singapore has been a significant entrepôt and trading post for at least two centuries. During the contemporary era, its ports have not become just a mere economic boon for the country, but an economic necessity making up for Singapore's land and natural resource limitations. Its ports are critical for importing natural resources, and then later re-exporting products after they have been domestically refined and shaped in some manner, for example wafer fabrication or oil refining to generate value added revenue. The Port of Singapore is also the world's largest bunkering port. The majority of ships that pass between the Indian Ocean and the Pacific Ocean go through the Singapore Strait.


title: Port of Singapore

text: Singapore is constructing the Tuas Mega Port to replace the current port at Keppel, with completion expected between 2025 and 2027. Built in four phases, it will be the world's largest container terminal when complete, and will be able to handle nearly 65 million TEUs annually. It will also have the infrastructure to cater to the largest container ships in the world, such as the Evergreen's A-class vessels and the ones by HMM and Maersk. The first phase with three berths opened in September 2022.


title: Port of Singapore

text: In the late 13th century, a Kingdom known as Singapura was established on the north bank of the Singapore River around what was called the Old Harbour. It was the only port in the southern part of the Strait of Malacca and serviced ships and traders in the region, competing with other ports along the coast of the Malacca Strait such as Jambi, Kota Cina, Lambri, Semudra, Palembang, South Kedah and Tamiang. The port had two functions. First, it made available products that were in demand by international markets; according to the "Daoyi Zhilüe" ("Brief Annals of Foreign Islands", 1349) by Chinese trader Wang Dayuan (born 1311, "fl." 1328–1339), these included top-quality hornbill casques, lakawood and cotton. Although these goods were also available from other Southeast Asian ports, those from Singapore were unique in terms of their quality. Secondly, Singapore acted as a gateway into the regional and international economic system for its immediate region. South Johor and the Riau Archipelago supplied products to Singapore for export elsewhere, while Singapore was the main source of foreign products to the region. Archaeological artefacts such as ceramics and glassware found in the Riau Archipelago evidence this. In addition, cotton was transshipped from Java or India through Singapore.


title: Port of Singapore

text: In 1984, an archaeological excavation had commenced at Fort Canning Hill led by the archaeologist Dr John Miksic. A range of artefacts including earthenware, ceramic, and porcelain pieces were found which suggests Singapore's role as an active trading port in the 14th century.


title: Port of Singapore

text: By the 15th century, Singapore had declined as an international trading port due to the ascendance of the Malacca Sultanate. Local trade continued on the island. A map of Singapore by Portuguese mathematician Manuel Godinho de Eredia showed the location of "Xabandaria" or the office of a "shahbandar", the Malay official responsible for international trade. Shards of 15th-century Siam ceramics and late 16th – or early 17th-century Chinese blue and white porcelain have been found at the Singapore and Kallang Rivers. Singapore also provided other regional ports with local products demanded by international markets. For instance, blackwood (a generic term used by Europeans to refer to rosewood) was exported from Singapore to Malacca, and was in turn purchased by Chinese traders and shipped to China for furniture-making:)


title: Port of Singapore

text: In the early 17th century, Singapore's main settlement and its port were destroyed by a punitive force from Aceh. After this incident, there was no significant settlement or port at Singapore until 1819.


title: Port of Singapore

text: In 1819, Stamford Raffles, a British colonial official, excited by the deep and sheltered waters in Keppel Harbour, established for the British Empire a new settlement and international port on the island or a trading port. Keen to attract Asian and European traders to the new port, Raffles directed that land along the banks of the Singapore River, particularly the south bank, be reclaimed where necessary and allocated to Chinese and English country traders to encourage them to establish a stake in the port-settlement. Chinese traders, because of their frequent commercial interactions with Southeast Asian traders throughout the year, set up their trading houses along the lower reaches of the river, while English country traders, who depended on the annual arrival of trade from India, set up warehouses along the upper reaches. The port relied on three main networks of trade that existed in Southeast Asia at that time: the Chinese network, which linked Southeast Asia with the southern Chinese ports of Fujian and Guangdong; the Southeast Asian network, which linked the islands of the Indonesian archipelago; and the European and Indian Ocean network, which linked Singapore to the markets of Europe and the Indian Ocean littoral. These networks were complementary, and positioned Singapore as the transshipment point of regional and international trade. By the 1830s, Singapore had overtaken Batavia (now Jakarta) as the centre of the Chinese junk trade, and also become the centre of English country trade, in Southeast Asia. This was because Southeast Asian traders preferred the free port of Singapore to other major regional ports which had cumbersome restrictions. Singapore had also supplanted Tanjung Pinang as the export gateway for the gambier and pepper industry of the Riau–Lingga Archipelago by the 1830s, and South Johor by the 1840s. It had also become the centre of the Teochew trade in marine produce and rice.


title: Port of Singapore

text: As the volume of its maritime trade increased in the 19th century, Singapore became a key port of call for sailing and steam vessels in their passage along Asian sea routes. From the 1840s, Singapore became an important coaling station for steam shipping networks that were beginning to form. Towards the late 19th century, Singapore became a staple port servicing the geographical hinterland of the Malay Peninsula. Following the institution of the British Forward Movement, Singapore became the administrative capital of British Malaya. Roads and railways were developed to transport primary materials such as crude oil, rubber and tin from the Malay Peninsula to Singapore to be processed into staple products, and then shipped to Britain and other international markets. During the colonial period, this was the most important role of the port of Singapore.


title: Port of Singapore

text: Singapore ceased to be part of the British Empire when it merged with Malaysia in 1963. Singapore lost its hinterland and was no longer the administrative or economic capital of the Malay Peninsula. The processing in Singapore of raw materials extracted in the Peninsula was drastically reduced due to the absence of a common market between Singapore and the Peninsular states.


title: Port of Singapore

text: Since Singapore's full independence in 1965, it has had to compete with other ports in the region to attract shipping and trade at its port. It has done so by developing an export-oriented economy based on value-added manufacturing. It obtains raw or partially manufactured products from regional and global markets and exports value-added products back to these markets through market access agreements such as World Trade Organization directives and free trade agreements.


title: Port of Singapore

text: By the 1980s, maritime trading activity had ceased in the vicinity of the Singapore River except in the form of passenger transport, as other terminals and harbours took over this role. Keppel Harbour is now home to three container terminals. Other terminals were built in Jurong and Pasir Panjang as well as in Sembawang in the north. Today, the port operations in Singapore are handled by two players: PSA International (formerly the Port of Singapore Authority) and Jurong Port, which collectively operate six container terminals and three general-purpose terminals around Singapore.


title: Port of Singapore

text: In the 1990s the Port became more well-known and overtook Yokohama, and eventually became the busiest port in terms of shipping tonnage.


title: Port of Singapore

text: Singapore is part of the Maritime Silk Road that runs from the Chinese coast to the southern tip of India, to Mombasa, from there through the Red Sea via the Suez Canal to the Mediterranean, to the Upper Adriatic region of the northern Italian hub Trieste with its rail connections to Central Europe and the North Sea.


title: Port of Singapore

text: The Tuas Mega Port is projected to be the only port in Singapore after the PSA city terminals and Pasir Panjang Terminal are closed in 2027 and 2040 respectively, ending an era of port operations in the city area which began in 1819. The Sea Transport Industry Transformation Map (ITM) launched by the Maritime and Port Authority of Singapore (MPA) aims to grow the industry's value-add by $4.5 billion and create more than 5,000 new jobs by 2025.


title: Port of Singapore

text: Automation will be a key part of the new port, with over 1,000 battery-powered driverless vehicles and a fleet of almost 1,000 automated yard cranes to be developed for the port. Nelson Quek, PSA Singapore's head of Tuas planning stated that "Tuas, when it's fully developed, is going to be the single largest fully-automated terminal in the world". It will also be able to cater to the demands of the world's largest container ships, with 26 km of deep-water berths. Besides just handling containers, the port will have space set aside for companies to be located, a move that aims to improve the links between port and businesses. It is projected to be twice the size of Ang Mo Kio new town.


title: Port of Singapore

text: Operations at Tuas Mega Port began in September 2021, and the port officially opened on September 1, 2022 with three berths in service.


title: Port of Singapore

text: The port is the world's busiest port in terms of shipping tonnage handled, with 1.15 billion gross tons (GT) handled in 2005. In terms of cargo tonnage, Singapore is behind Shanghai with 423 million freight tons handled. The port retains its position as the world's busiest hub for transshipment traffic in 2005, and is also the world's biggest bunkering hub, with 25 million tonnes sold in the same year.


title: Port of Singapore

text: Singapore is ranked first globally in 2005 in terms of containerised traffic, with 23.2 million Twenty-foot equivalent units (TEUs) handled. High growth in containerised traffic has seen the port overtaking Hong Kong since the first quarter of 2005, and has led the race ever since, with an estimated 19,335 kTEUs handled in the year up to October, compared to 18,640 kTEUs handled in Hong Kong in the same period. A rise in regional traffic consolidating the port's position in Southeast Asia, and increases in transshipment traffic using the strategic East Asia-Europe route via Singapore helped the port to emerge tops at the end of the year, a title it had not held since overtaking Hong Kong once in 1998.


title: Port of Singapore

text: PSA Singapore has 13 berths which are part of the Pasir Panjang Container Terminal's Phase Two which are due for completion by 2009. Phase Three and Four will add another 16 berths and are expected to be completed by 2013.


title: Port of Singapore

text: PSA Singapore also has a 40-year contract to operate the tax-free Gwadar Port on the southwestern coast of Pakistan. Gwadar started operation in March 2008, with 3 multi-purpose berths, a 602-meter quay, and 12.5-meter depth. Another 9 berths are under construction, with a 20-meter depth. In 2015, it was announced that the port would be leased to the Chinese till 2059 and further developed under the China-Pakistan Economic Corridor.


title: Murder of Tammy Alexander

text: Tammy Jo Alexander (November 2, 1963 – November 9, 1979) was an American teenage girl who was found murdered in the town of Caledonia, New York, on November 10, 1979. She had been fatally shot twice and left in a field just off U.S. Route 20 near the Genesee River after running away from her home in Brooksville, Florida earlier that year. For more than three decades, she remained unidentified under the name Caledonia Jane Doe or "Cali Doe" until January 26, 2015, when police in Livingston County, New York announced her identity 35 years after her death.


title: Murder of Tammy Alexander

text: Alexander was 16 years old when murdered, though her age was not clear to investigators at the time. Most potential forensic evidence was washed away by heavy rain on the night she died, but they knew she had come to the Caledonia area from a distant, warmer locale because she had tan lines on her upper body. Advances in technology allowed investigators to make use of rapidly improving and new forensic techniques to evaluate trace evidence they had collected and, following a successful DNA extraction from her remains in 2005 and a palynological analysis of Alexander's clothing, they concluded that she had spent time in Florida, southern California, Arizona, or northern Mexico prior to her death. Later analysis of isotopes in her bones would lend further support to this conclusion. In addition, a portrait was made of her based on a facial reconstruction, in the hopes that someone would recognize her image, and it was uploaded to an online public database in 2010.


title: Murder of Tammy Alexander

text: Identification was achieved based on a combination of factors; in 2014, a renewed search for her by a close high school friend and Alexander's half-sister resulted in the filing of a new missing persons report with police in Hernando County, Florida, as she had not been seen or heard from since the late 1970s. The artist of the reconstructed photo, a moderator at the Websleuths online community, notified the Livingston County Sheriff's Office about a potential match between the two pictures, and in 2015 a follow-up mitochondrial DNA (mtDNA) analysis confirmed a match with Alexander's half-sister based on the DNA results from 2005.


title: Murder of Tammy Alexander

text: Alexander's case was well-publicized in the time she was unidentified, and the Livingston County police continued to process thousands of leads from the public. The investigation stalled in 1980, leading county officials to arrange for her burial as "Unidentified Girl" at Greenmount Cemetery in Dansville, New York. In 1984, serial killer Henry Lee Lucas confessed to the crime, but his statement was not considered credible. The perpetrator remains unidentified.


title: Murder of Tammy Alexander

text: Tammy Jo Alexander was born in Atlanta, Georgia on November 2, 1963, and attended high school in Brooksville, Florida. Pamela Dyson, Alexander's half-sister, believes that Alexander left to escape a turbulent household. Dyson had a different father from Alexander, and, after about age 11, she lived with her paternal grandmother. She said that Alexander's biological father was not really part of the younger girl's life; she grew up with their mother and a stepfather. Their mother had become addicted to prescription medication and was emotionally volatile, erupting into temper tantrums. "She did prescription drugs," Dyson said of her mother, Barbara. "She was suicidal. I think she had issues back then that they didn't diagnose."


title: Murder of Tammy Alexander

text: Alexander's mother, Barbara Jenkins, had worked as a waitress at a truck stop, and was joined by Alexander when she was a teenager. Alexander had a history of running away in this period. Her friend Laurel Nowell said that they had sometimes hitchhiked together with truckers, once traveling all the way to California together. When they got there, Nowell called her parents, and they paid for airline tickets for both girls so they could return to Florida. Jenkins died on January 17, 1998, at the age of 56. Her obituary had listed Alexander as deceased, which the family had assumed to be the case by that time.


title: Murder of Tammy Alexander

text: Until the identification, Dyson believed that her half-sister had made a new life somewhere away from her mother and stepfather. She had hoped that it included a happy household, with a husband and children. "I thought she just wanted to go away and start all over," Dyson said.


title: Murder of Tammy Alexander

text: Alexander was discovered on the morning of November 10, 1979, by a farmer in Caledonia, New York, southwest of the city of Rochester. The farmer saw red clothing in one of his corn fields near the Genesee River and went to investigate, believing that he had spotted a trespassing hunter. Instead, he found the body of a young woman and notified police soon after.


title: Murder of Tammy Alexander

text: Alexander was fully clothed and showed no signs of sexual assault. Investigators initially ruled that she had died from a severe hemorrhage caused by two gunshot wounds, one to the head over the right eye and one to the back. The wound to the head indicated she had apparently not turned or flinched, a common phenomenon of a headshot, and the entry wound suggested complete surprise. With her pockets turned inside out to indicate that any identification she carried had been removed, the investigators later named her "Caledonia Jane Doe" or "Cali Doe" as they worked to identify her.


title: Murder of Tammy Alexander

text: The autopsy by the medical examiner indicated that Alexander had first been shot in the head while next to the road bordering the cornfield, at or near a blood spot found on the ground. She was dragged into the cornfield, where she was shot again in the back and left for dead. Heavy rains on the night of Alexander's death washed away a large portion of potential forensic evidence, such as physical and DNA traces of the perpetrator on her body and clothes.


title: Murder of Tammy Alexander

text: In the 1980s, John York, who had been one of the first Livingston County deputy sheriffs on the scene in 1979, was elected sheriff. He served in the job until 2013, and ensured that the Cali Doe investigation remained active. Before she was identified, Alexander was estimated to have died between the ages of 13 and 19 (born sometime between 1958 and 1967). She was also estimated to be and . Alexander was described as having brown eyes and wavy, light brown shoulder-length hair that had been lightened in the front about four months prior to her death and was growing out, and her toenails were painted with coral-colored polish.


title: Murder of Tammy Alexander

text: Alexander had visible tan lines from a halter top or bikini, indicating that she may have come from a region with abundant October–November sunshine, as sun tanning beds were uncommon in the 1970s and Upstate New York was not considered warm or sunny enough for such tanning during that period. There were freckles on the back of her shoulders and acne on her face and chest.


title: Murder of Tammy Alexander

text: The teeth were in natural condition, with no restorations or fillings. It did not appear as if she had ever received dental care. Some of Alexander's permanent first and second molars suffered from severe dental caries (cavities and decay). Consistent with her young appearance, none of her permanent third molars (wisdom teeth) had erupted. Her blood type was A−. Several hours before her death, Alexander had eaten sweet corn, potatoes, and boiled canned ham. This was possibly from a diner in nearby Lima, where a waitress had seen her eating with an adult man. At the time of exhumation, several of the victim's teeth were sent for mineralogical and forensic isotope analysis. The composition of her teeth could be linked to the composition and mineral content of regional drinking water supplies around North America, allowing investigators to determine where she may have been raised. Early results on the dental O/O isotopic oxygen ratio indicated that she may have spent her early years in the south/southwest region of the United States.


title: Murder of Tammy Alexander

text: Alexander was wearing a red nylon-lined man's windbreaker jacket with black stripes down the arms, marked inside with the label "Auto Sports Products, Inc.", a boy's multicolored plaid button-up shirt with collar, tan corduroy pants (size 7), blue knee socks, white bra (size 32C), and blue panties. She wore brown ripple-soled shoes. The red Auto Sports Products jacket was produced as a one-time promotional item and could not be traced after distribution. She also wore a silver necklace with three small turquoise stones. The necklace had a homemade appearance and resembled replica Native American jewelry made in the southwestern United States. Attached to her pants' front belt loops were two metal keychains, one shaped like a heart with a key-shaped cutout and inscribed with the words, "He who holds the Key can open my heart", the other shaped like a key meant to fit the cutout in the heart. The keychains were sold at vending machines along the New York State Thruway, leading investigators to conclude that she and her killer had traveled that route.


title: Murder of Tammy Alexander

text: In 2006, forensic palynology was conducted on the clothing worn by the victim. Paul Chambers, a recently hired investigator in the Monroe County, New York medical examiner's office, asked for and received permission to send her clothing to the Palynology Laboratory at Texas A&M University. Among the types of pollen found on the clothing by the Texas A&M researchers were grains from "Casuarina" (Australian pine, or "she oak"), "Quercus" (oak), "Picea" (spruce), and "Betula" (birch). The clothing pollen grains were compared to a control sample of pollen grains taken directly from the rural New York site where the body had been found in 1979.


title: Murder of Tammy Alexander

text: Oak grows widely all over the U.S., and spruce and birch grow in New York, among many places in the country. But no oak, spruce, or birch pollen grains were found in the control sample, and neither spruce nor birch trees were found growing near the body dump site. The spruce and birch pollen on the unidentified body came from species common in mountainous areas of California.


title: Murder of Tammy Alexander

text: Australian pine is an invasive genus of tree that grows in a limited number of locations in North America: south Florida; south Texas; parts of Mexico; the campuses of the University of Arizona and Arizona State University; and three regions in California: the North Bay of San Francisco, the San Luis Obispo area, and the San Diego area. The tree cannot survive the autumn and winter seasons in the temperate climate of western New York, where the body was found. Thus, investigators knew that Alexander and her clothing had acquired the "Casuarina" pollen grains at a location other than the dump site.


title: Murder of Tammy Alexander

text: Researchers believed the southern California and San Diego region to be the best geographical pollen print match location for the grains from the clothing. Based on the pollen evidence and the girl's visible tan lines, forensic researchers suggested that she may have been living in the southwestern United States near San Diego, then traveled (perhaps by hitchhiking) through the Sierra Nevada mountains, where spruce and birch grow, passing through Reno, Nevada and eventually across the country to upstate New York.


title: Murder of Tammy Alexander

text: A 2012 reexamination of the grains concluded, again, that they could have originated only from California, Arizona, or Florida.


title: Murder of Tammy Alexander

text: Alexander was formally identified on January 26, 2015, more than 35 years after her discovery. Laurel Nowell, a close friend in high school from Brooksville, Florida, had started trying to reach Alexander in the 2010s by social media. She eventually reached Alexander's half-sister, Pamela Dyson, of Panama City, who knew that she had often run away from home, but Dyson had not lived with her younger half-sister after about age 11. She learned that no one in her family knew anything of Alexander's whereabouts since the girl had left sometime between 1977 and 1979. An ex-boyfriend of the victim verified he'd last seen her in the spring of 1979. It is believed the victim hitched a ride while working as a waitress at the truck stop owned by her parents.


title: Murder of Tammy Alexander

text: Dyson and Nowell became concerned that Alexander had fallen victim to a crime after leaving home. Dyson said that her mother did report Alexander as missing, but she has since believed that, since Alexander had a history of running away and returning, police may not have taken the case seriously. In August 2014, the Hernando County sheriff's office told them no missing persons report had been filed for her, and promptly filed one.


title: Murder of Tammy Alexander

text: Carl Koppelman, a California artist, came across the "missing person" report on Alexander as a moderator of the Websleuths online community, where volunteers try to solve cold cases including those of unidentified bodies. In 2010, four years earlier, he had sketched the portrait of "Caledonia Jane Doe" and posted it in the National Missing and Unidentified Persons System (NamUs). In September 2014, he saw the new listing for Alexander and quickly realized that they were the same person. He emailed the Livingston County Sheriff's Office (with copies sent to the NamUs regional administrator, the National Center for Missing and Exploited Children (NCMEC), and the Hernando County Sheriff's Office) to tell them of the strong resemblance between the two images. Police arranged to take a DNA sample from Dyson.


title: Murder of Tammy Alexander

text: In January 2015, the Monroe County medical examiner's office found that MtDNA from the unidentified body matched that of Dyson, confirming that the victim was her half-sister. A week later on January 26, 2015, the Livingston County sheriff, Thomas Dougherty, announced at a news conference that Caledonia Jane Doe had been identified after 35 years.


title: Murder of Tammy Alexander

text: Dyson said the family decided to keep Alexander buried in the Greenmount Cemetery in Dansville, New York, planning to hold a service there for her. "I'm truly glad for the closure," [Dyson] said. "But it hurts to know she died that way. It's terrible, nobody should have to be shot and dragged out into the woods." The Dougherty Funeral Home in Livonia, New York said it paid to have the "Jane Doe" headstone removed and replaced with one reading "Tammy Jo Alexander". A public ceremony took place on June 10, 2015, when the new headstone, displaying the victim's name and lifespan, was revealed. Approximately one hundred family and community members attended. Dyson and other members of the Alexander family thanked the police and Livingston community for their caring for Alexander and continued efforts to find her killer.


title: Murder of Tammy Alexander

text: Dyson has since urged family members of missing people to enter the subjects into NamUs, saying that this database was critical in achieving her sister's identification.


title: Murder of Tammy Alexander

text: The Livingston County Sheriff's Office released three audio clips of Alexander's voice on November 2, 2020, which would have been the victim's 57th birthday. She was believed to have created the recordings during July 1979 on a cassette tape, which she sent to her boyfriend, who had kept it in his possession until he provided it to the investigative agency.


title: Murder of Tammy Alexander

text: Sheriff Dougherty has said the investigation would now focus on finding out who killed Alexander. "We've always said one of the biggest parts of solving this case is knowing the victim," he told the media. "This case is burning hot ... We're going to be working it harder than ever." Former sheriff York later said that more than 10,000 leads had already been investigated in the case.


title: Murder of Tammy Alexander

text: Alexander was seen with a white male between five feet eight and five feet nine inches tall. He was seen driving a tan station wagon and wore black wire-rimmed glasses. The man was stated to be a "person of interest" in the case, and police continue to seek his identity. The waitress at the diner, who served the pair on the night of Alexander's death, explained the male companion had paid for the meal.


title: Murder of Tammy Alexander

text: In 1984, serial killer Henry Lee Lucas confessed to the murder of the unidentified girl, without identifying her. Investigators could not find sufficient evidence to support his confession. At one time, a now-retired sheriff speculated Christopher Wilder, known for a span of murdering women in the 1980s, may have been responsible. This theory was rooted in his interest in vehicle racing, and Alexander's jacket was of the same brand of merchandise he was known to purchase. Wilder was killed in a police shootout in 1984 before an interview regarding the Alexander case could take place.


title: Murder of Tammy Alexander

text: Police speculate that the murder weapon the killer used was a .38-caliber handgun. Investigators located a spent slug in the dirt underneath the unidentified girl's body, which they compared forensically to hundreds of other bullets fired from confiscated weapons. Despite investigators' efforts to trace weapons from the U.S., Canada, Europe, and Mexico, the slug has not been matched to a specific gun.


title: Murder of Tammy Alexander

text: The FBI posted billboards throughout the country about Alexander's murder in an attempt to gain new information from the public. By the end of February 2015, the Livingston County Sheriff's Department said they had received many more tips since Alexander's identification, enough to develop a scenario of events that led up to the girl's arrival in Caledonia. A trucker from Tennessee reported what police said was a "significant" lead after he had heard a radio broadcast detailing the case.


title: Murder of Tammy Alexander

text: In March 2015, the department said that Alexander had ties to a former "prison ministry" in Young Harris, Georgia, which specialized in working with individuals "on probation or parole." By early 2016, the police had identified three male persons of interest who had known Alexander, and took male DNA from her clothing. By November 2016, the FBI had reported that none of the three matched the sample from Alexander's clothing, and continued to receive and investigate new leads in the case. By 2020, it was announced that the male DNA found on Alexander’s clothing was now being tested against national databases in search of a familial link to the killer.


title: Murder of Tammy Alexander

text: In the decades she remained unidentified, the case received national attention. It was featured on such television shows as "America's Most Wanted". After her discovery, two news organizations in Rochester, New York, partnered to produce a multi-part podcast in May 2016 detailing Alexander's murder and the ongoing investigation called "Finding Tammy Jo". It was hosted by reporters Veronica Volk from WXXI News and Gary Craig from "The Democrat and Chronicle", who spent a year co-reporting on the case. They had interviewed potential witnesses, law enforcement, and Alexander's family and friends.


title: Lee Yoon-hyung

text: Lee Yoon-hyung (; ; April 26, 1979 – November 18, 2005) was a South Korean millionaire and daughter of Samsung Group chief Lee Kun-hee. She died by suicide by hanging herself in her New York City apartment on November 18, 2005 at the age of 26.


title: Lee Yoon-hyung

text: On April 26, 1979, Lee was born in South Korea. Her father was Samsung chairman Lee Kun-hee, and her mother was Hong Ra-hee. She was the youngest of the four children; she had an elder brother Lee Jae-yong and two elder sisters Lee Boo-jin and Lee Seo-hyun.


title: Lee Yoon-hyung

text: Lee graduated from Ewha Womans University in Seoul with a Bachelor of Arts degree in French language and French literature. She was a first-year graduate student in arts management at New York University's Steinhardt School of Culture, Education, and Human Development.


title: Lee Yoon-hyung

text: In her spare time, she was very keen on car racing and many extreme sports. She also launched a personal blog to show her daily life to the public and it became very popular in South Korea.


title: Lee Yoon-hyung

text: Her cause of death was originally reported in both American and South Korean media as a car crash due to the social stigma against suicide, but the actual details were subsequently published after inquiries by reporters from "The Korea Times". At the time of her death, Lee was a graduate student at the New York University Steinhardt School of Culture, Education, and Human Development, and her father was in the United States undergoing treatment for lung cancer. A doorman at her building told reporters that she sometimes stayed in her apartment for a week at a time, and there were reports that her father had forbidden her to marry her middle-class Korean boyfriend. At the time of her death, Lee had a personal fortune of more than £100 million ($157 million).


title: The Lion and the Jewel

text: The Lion and the Jewel is a play by Nigerian writer Wole Soyinka that was first performed in 1959 in Ibadan. In 1966, it was staged in London at the Royal Court Theatre. The play chronicles how Baroka, the lion, fights with the modern Lakunle over the right to marry Sidi, the titular Jewel. Lakunle is portrayed as the civilized antithesis of Baroka and unilaterally attempts to modernize his community and change its social conventions for no reason other than the fact that he can. The transcript of the play was first published in 1962 by Oxford University Press. Soyinka emphasises the theme of the corrupted African culture through the play, as well as how the youth should embrace the original African culture. A review by Naijabanquet describes "The Lion and the Jewel" as "a masterpiece that successfully combines the concept of literature as a tool both for socio-cultural activism and shining spotlight on aesthetics."


title: The Lion and the Jewel

text: the play opens with a school teacher, Lakunle, who is teaching a class when Sidi walks fast carrying a pail of water on her head. The teacher peers out of the window and disappears. Two 11-year-old school children start ogling her, so he hits them on the head and leaves to confront her. Lakunle comes out and insists on taking the pail from Sidi. She refuses, saying that she would look silly. Lakunle tells her not to carry loads on her head or her neck may be shortened. He also tells her not to expose so much of her cleavage with the cloth she wears around her breasts. Sidi says that it is too inconvenient for her to do so. She scolds him, saying that the village thinks he's stupid, but Lakunle says that he is not so easily cowed by taunts. Lakunle also insults her saying that her brain is smaller than his because of her feminine gender(which proves his semi-literacy, mentioned at first), making her angry.


title: The Lion and the Jewel

text: After arguing, Sidi wants to leave, but Lakunle tells her of his love for her, but she remains indifferent. Eventually, it is revealed that Sidi does not want to marry him because Lakunle refuses to pay her bride-price as he thinks it is an uncivilized, outrageous custom. Sidi tells him that if she did so, people will jeer at her, saying that she is not a virgin. Lakunle further professes how he wants to marry her and treat her "just like the Lagos couples I have seen". Sidi does not care. She also says that she finds the Western custom of kissing repulsive. She tells him that not paying her bride price is mean and miserly.


title: The Lion and the Jewel

text: Soon, a village girl came to announce to Sidi the arrival of the stranger and the photo album he brought along bearing pictures of the village. As the village girls enter, they play "The Dance of the Lost Traveller", which features the sudden arrival of a photographer in their midst some time ago. They tease the traveller in the play, calling his motorbike "the devil's own horse" and the camera that he used to take pictures "the one-eyed box". Four girls act the "devil-horse", a youth is selected to play the snake, and Lakunle becomes the Traveller. He seeks to be excused to teach Primary Four Geography but Sidi informs him that the village is on holiday due to the arrival of the photographer/traveler.


title: The Lion and the Jewel

text: We also find out that the photographer made a picture book about the village based on the photos he took. There is a picture of Sidi on the front page, and a two-page spread of her somewhere inside. Baroka is featured too, but he "is in a little corner somewhere in the book, and that corner he shares with one of the village latrines". They banter about for a while, Lakunle gave in and participated because he couldn't tolerate being taunted by them.


title: The Lion and the Jewel

text: The four girls kneeled on the ground, forming the wheels of the car. Lakunle adjusts their position and sits in air in the middle. He pretends to drive the "car". The girls dance the stall. They shudder, and drop their faces onto their laps. He pretends to try to restart the "car". He gets out and checks the "wheels" and also pinches them. He tries to start the "car", fails and takes his things for a trek.


title: The Lion and the Jewel

text: He hears a girl misbehaving, but attributes it to sunstroke, so he throws the bottle that he was drinking from in that general direction. He hears a scream and a torrent of abuse. He takes a closer look and sees a girl (played by Sidi). He tries to take photos, but falls down into the stream.


title: The Lion and the Jewel

text: The cast assembles behind him, pretending to be villagers in an ugly mood hauling him to the maram in the town centre. Then Baroka appears and the play stops. He talks to Lakunle for a while, saying that he knew how the play went and was waiting for the right time to step in. He drops subtle hints of an existing feud between him and Lakunle, then makes the play continue. The villagers once again start thirsting for his blood. He is hauled before Baroka, thrown on his face. He tries to explain his plight. Baroka seems to understand and orders a feast in the Lost Traveller's honour. He then takes the opportunity to take more photos of Sidi. He is also pressed to drink much alcohol, and at the end of the play, he is close to vomiting.


title: The Lion and the Jewel

text: The play ends. Sidi praises him for his performance. Lakunle runs away, followed by a flock of women. Baroka and the wrestler sit alone. Baroka takes out his book, and muses that it has been five full months since he last took a wife.


title: The Lion and the Jewel

text: Sidi is at a road near the marketplace. Lakunle follows her, while carrying the firewood that Sidi asked him to help her get. She admires the pictures of her in the magazine. Then Sadiku appears wearing a shawl over her head. She informs her that the Lion (Baroka) wishes to take her as a wife. Lakunle is outraged, but Sidi stops him. Lakunle changes tactics, telling her as his lover to ignore the message. Sadiku took that as a yes, but Sidi dashed her hopes, saying that since her fame had spread to Lagos and the rest of the world, she deserves more than that. Sadiku presses on, dissembling that Baroka has sworn not to take any more wives after her and that she would be his favourite and would get many privileges, including being able to sleep in the palace rather than one of the outhouses. As Baroka's last wife, she would also be able to become the first, and thus head wife, of his successor, in the same way that Sadiku was Baroka's head wife. However, Sidi sees through her lies, and tells her that she knew that he just wanted fame "as the one man who has possessed 'the jewel of Ilujinle'". Sadiku is flabbergasted, she insults and attempt to hit Lakunle for what he has done to her.


title: The Lion and the Jewel

text: Sidi shows the magazine. She says that in the picture, she looks absolutely beautiful while he simply looks like a ragged, blackened piece of saddle leather: she is youthful but he is spent. Sadiku changes techniques, saying that if Sidi does not want to be his wife, will she be kind enough to attend a small feast in her honour at his house that night. Sidi refuses, saying that she knows that every woman who has eaten supper with him eventually becomes his wife. Lakunle interjects, informing them that Baroka was known for his wiliness, particularly when he managed to foil the Public Works attempt to build a railroad through Ilujinle. Baroka bribed the surveyor for the route to move the railroad much farther away as "the earth is most unsuitable, could not possibly support the weight of a railway engine". Lakunle is distraught, as he thinks just how close Ilujinle was to civilisation at that time.


title: The Lion and the Jewel

text: The scene cuts to Baroka's bedroom. Ailatu is plucking his armpit hairs. There is a strange machine with a long lever at the side. It is covered with animal skins and rugs. Baroka mentions that she is too soft with her pulls. Then he tells her that he plans to take a new wife, but that he would let her be the "sole out-puller of my sweat-bathed hairs". She is angry, and deliberately plucks the next few hairs a lot harder. Sadiku enters. He shoos Ailatu away, lamenting about his bleeding armpit.


title: The Lion and the Jewel

text: Sadiku informs him that she failed to woo Sidi. She told him that Sidi flatly refused her order, claiming that he was far too old. Baroka pretends to doubt his manliness and asks Sadiku to massage the soles of his feet. Sadiku complies. He lies to her that his manhood ended a week ago, specifically warning her not to tell anyone. He comments that he is only 62. Compared to him, his grandfather had fathered two sons late on 65 and Okiki, his father, produced a pair of female twins at 67. Finally Baroka falls asleep.


title: The Lion and the Jewel

text: Sidi is at the village center square, by the schoolroom window. Enter Sadiku, who is carrying a bundle. She sets down a figure by the tree. She gloats, saying that she has managed to be the undoing (making him impotent) of Baroka, and of his father, Okiki, before that. Sidi is amazed at what she initially perceives to be Sadiku going mad. She shuts the window and exits, shocking Sadiku. After a pause, Sadiku resumes her victory dance and even asks Sidi to join in. Then Lakunle enters. He scorns them, saying: "The full moon is not yet, but the women cannot wait. They must go mad without it." Sidi and Sadiku stop dancing. They talk for a while. As they are about to resume dancing, Sidi states her plans to visit Baroka for his feast and toy with him. Lakunle tries in vain to stop her, telling her that if her deception were to be discovered she would be beaten up. Sidi leaves. Lakunle and Sadiku converse. Lakunle states his grand plans to modernize the area by abolishing the bride-price, building a motor-road through the town and bring city ways to isolated Ilujinle. He goes on to spurn her, calling her a bride-collector for Baroka.


title: The Lion and the Jewel

text: The scene is now Baroka's bedroom. Baroka is arm-wrestling the wrestler seen earlier. He is surprised that she (Sidi) managed to enter unchallenged. Then he suddenly remembers that that day was the designated day off for the servants. He laments that Lakunle had made his servants form an entity called the Palace Workers' Union. He asks if Ailatu was at her usual place, and was disappointed to find out that she had not left him yet despite scolding her severely. Then Sidi mentions that she was here for the supper. Sidi starts playing around with Baroka. She asks him what was up between him and Ailatu. He is annoyed. Changing the subject, Sidi says that she thinks Baroka will win the ongoing arm-wrestling match. Baroka responds humbly, complimenting the strength and ability of the wrestler. She slowly teases Baroka, asking if he was planning to take a wife. She draws an example, asking if he was her father, would he let her marry a person like him?


title: The Lion and the Jewel

text: Sidi takes this opportunity to slightly tease him, and is rewarded by his violent reaction by taking the wrestler and slinging him over his shoulder. The wrestler quickly recovers and a new match begins again. The discussion continues. Baroka is hurt by the parallels and subtle hints about his nature dropped by Sidi. Sidi even taunts him, saying that he has failed to produce any children for the last two years. Eventually he is so angered that he slams the wrestler's arm down on the table, winning the match. He tells the defeated wrestler to get the fresh gourd by the door. In the meantime, Baroka tries to paint himself as a grumpy old man with few chances to show his kindliness. The wrestler returns. Baroka continues with his self-glorification. Then he shows her the now-familiar magazine and an addressed envelope. He shows her a stamp, featuring her likeness, and tells her that her picture would adorn the official stamp of the village. The machine at the side of his room is also revealed to be a machine to produce stamps. As she admires the pictures of her in the magazine, Baroka happens to mention that he does not hate progress, only its nature which made "all roofs and faces look the same". He continues praising Sidi's looks, appealing to her.


title: The Lion and the Jewel

text: The scene cuts back to the village centre, where Lakunle is pacing in frustration. He is mad at Sadiku for tricking her to go see Baroka, and at the same time concerned that Baroka will harm or imprison her. Some mummers arrive. Sadiku remains calm, despite Lakunle's growing stress. Sadiku steals a coin from Lakunle to pay the mummers. In return, the mummers drum her praises, but Sadiku claims that Lakunle was the real benefactor. Then they dance the Baroka story, showing him at his prime and his eventual downfall. Lakunle is pleased by the parts where they mock Baroka. Sadiku mentions that she used to be known as Sadiku of the duiker's feet because she could twist and untwist her waist with the smoothness of a water snake.


title: The Lion and the Jewel

text: Sidi appears. She is distraught. Lakunle is outraged, and plans to bring the case to court. Sidi reveals that Baroka only told her at the end that it was a trap. Baroka said that he knew that Sadiku would not keep it to herself, and go out and mock his pride. Lakunle is overcome with emotion, and after at first expressing deep despair, he offers to marry her instead, with no bride-price since she is not a virgin after all. Lakunle is pleased that things have gone as he hoped. Sadiku tells him that Sidi is preparing for a wedding. Lakunle is very happy, saying he needs a day or two to get things ready for a proper Christian wedding. Then musicians appear. Sidi appears, bearing a gift. She tells Lakunle that he is invited to her wedding. Lakunle hopes that the wedding will be between Sidi and himself, but she informs him that she has no intention of marrying him, but rather will marry Baroka. Lakunle is stunned. Sidi says that between Baroka and him, at sixty, Baroka is still full of life but Lakunle would be probably "ten years dead". Sadiku then gives Sidi her blessing. The marriage ceremony continues. A young girl taunts Lakunle, and he gives chase. Sadiku gets in his way. He frees himself and clears a space in the crowd for them both to dance.


title: The Lion and the Jewel

text: The most prominent theme of this story is the rapid modernisation of Africa, coupled with the rapid evangelisation of the population. This has driven a wedge between the traditionalists, who seek to nullify the changes done in the name of progress due to vested interests or simply not liking the result of progress, and the modernists, who want to see the last of outdated traditional beliefs at all cost.


title: The Lion and the Jewel

text: Another core theme is the marginalisation of women as property. Traditionally, they were seen as properties that could be bought, sold or accumulated. Even the modern Lakunle falls victim to this, by looking down on Sidi for having a smaller brain, and later by thinking it will be easier to marry her once she's lost her virginity, since no dowry was required in such a situation.


title: The Lion and the Jewel

text: There is also the conflict between education and traditional beliefs. The educated people seek to spread their knowledge to the tribal people in an attempt to make them more modern. This in turn is resisted by the tribal people who see no point in obtaining an education as it served them no use in their daily lives.


title: The Lion and the Jewel

text: Finally, there is the importance of song and dance as a form of spreading information in a world where the fastest route of communication is by foot. It is also an important source of entertainment for the otherwise bored village youths. The author shows the slow influence of modernisation, for example, the wandering traveller influences Sidi's life drastically.


title: Thermal runaway

text: Thermal runaway describes a process that is accelerated by increased temperature, in turn releasing energy that further increases temperature. Thermal runaway occurs in situations where an increase in temperature changes the conditions in a way that causes a further increase in temperature, often leading to a destructive result. It is a kind of uncontrolled positive feedback.


title: Thermal runaway

text: In chemistry (and chemical engineering), thermal runaway is associated with strongly exothermic reactions that are accelerated by temperature rise. In electrical engineering, thermal runaway is typically associated with increased current flow and power dissipation. Thermal runaway can occur in civil engineering, notably when the heat released by large amounts of curing concrete is not controlled. In astrophysics, runaway nuclear fusion reactions in stars can lead to nova and several types of supernova explosions, and also occur as a less dramatic event in the normal evolution of solar-mass stars, the "helium flash".


title: Thermal runaway

text: Some climate researchers have postulated that a global average temperature increase of 3–4 degrees Celsius above the preindustrial baseline could lead to a further unchecked increase in surface temperatures. For example, releases of methane, a greenhouse gas more potent than CO, from wetlands, melting permafrost and continental margin seabed clathrate deposits could be subject to positive feedback.


title: Thermal runaway

text: Chemical reactions involving thermal runaway are also called thermal explosions in chemical engineering, or runaway reactions in organic chemistry. It is a process by which an exothermic reaction goes out of control: the reaction rate increases due to an increase in temperature, causing a further increase in temperature and hence a further rapid increase in the reaction rate. This has contributed to industrial chemical accidents, most notably the 1947 Texas City disaster from overheated ammonium nitrate in a ship's hold, and the 1976 explosion of zoalene, in a drier, at King's Lynn. Frank-Kamenetskii theory provides a simplified analytical model for thermal explosion. Chain branching is an additional positive feedback mechanism which may also cause temperature to skyrocket because of rapidly increasing reaction rate.


title: Thermal runaway

text: Chemical reactions are either endothermic or exothermic, as expressed by their change in enthalpy. Many reactions are highly exothermic, so many industrial-scale and oil refinery processes have some level of risk of thermal runaway. These include hydrocracking, hydrogenation, alkylation (S2), oxidation, metalation and nucleophilic aromatic substitution. For example, oxidation of cyclohexane into cyclohexanol and cyclohexanone and ortho-xylene into phthalic anhydride have led to catastrophic explosions when reaction control failed.


title: Thermal runaway

text: Thermal runaway may result from unwanted exothermic side reaction(s) that begin at higher temperatures, following an initial accidental overheating of the reaction mixture. This scenario was behind the Seveso disaster, where thermal runaway heated a reaction to temperatures such that in addition to the intended 2,4,5-trichlorophenol, poisonous 2,3,7,8-tetrachlorodibenzo-"p"-dioxin was also produced, and was vented into the environment after the reactor's rupture disk burst.


title: Thermal runaway

text: Thermal runaway is most often caused by failure of the reactor vessel's cooling system. Failure of the mixer can result in localized heating, which initiates thermal runaway. Similarly, in flow reactors, localized insufficient mixing causes hotspots to form, wherein thermal runaway conditions occur, which causes violent blowouts of reactor contents and catalysts. Incorrect equipment component installation is also a common cause. Many chemical production facilities are designed with high-volume emergency venting, a measure to limit the extent of injury and property damage when such accidents occur.


title: Thermal runaway

text: At large scale, it is unsafe to "charge all reagents and mix", as is done in laboratory scale. This is because the amount of reaction scales with the cube of the size of the vessel (V ∝ r³), but the heat transfer area scales with the square of the size (A ∝ r²), so that the heat production-to-area ratio scales with the size (V/A ∝ r). Consequently, reactions that easily cool fast enough in the laboratory can dangerously self-heat at ton scale. In 2007, this kind of erroneous procedure caused an explosion of a -reactor used to metalate methylcyclopentadiene with metallic sodium, causing the loss of four lives and parts of the reactor being flung away. Thus, industrial scale reactions prone to thermal runaway are preferably controlled by the addition of one reagent at a rate corresponding to the available cooling capacity.


title: Thermal runaway

text: Some laboratory reactions must be run under extreme cooling, because they are very prone to hazardous thermal runaway. For example, in Swern oxidation, the formation of sulfonium chloride must be performed in a cooled system (−30 °C), because at room temperature the reaction undergoes explosive thermal runaway.


title: Thermal runaway

text: Microwaves are used for heating of various materials in cooking and various industrial processes. The rate of heating of the material depends on the energy absorption, which depends on the dielectric constant of the material. The dependence of dielectric constant on temperature varies for different materials; some materials display significant increase with increasing temperature. This behavior, when the material gets exposed to microwaves, leads to selective local overheating, as the warmer areas are better able to accept further energy than the colder areas—potentially dangerous especially for thermal insulators, where the heat exchange between the hot spots and the rest of the material is slow. These materials are called "thermal runaway materials". This phenomenon occurs in some ceramics.


title: Thermal runaway

text: Some electronic components develop lower resistances or lower triggering voltages (for nonlinear resistances) as their internal temperature increases. If circuit conditions cause markedly increased current flow in these situations, increased power dissipation may raise the temperature further by Joule heating. A vicious circle or positive feedback effect of thermal runaway can cause failure, sometimes in a spectacular fashion (e.g. electrical explosion or fire). To prevent these hazards, well-designed electronic systems typically incorporate current limiting protection, such as thermal fuses, circuit breakers, or PTC current limiters.


title: Thermal runaway

text: To handle larger currents, circuit designers may connect multiple lower-capacity devices (e.g. transistors, diodes, or MOVs) in parallel. This technique can work well, but is susceptible to a phenomenon called current hogging, in which the current is not shared equally across all devices. Typically, one device may have a slightly lower resistance, and thus draws more current, heating it more than its sibling devices, causing its resistance to drop further. The electrical load ends up funneling into a single device, which then rapidly fails. Thus, an array of devices may end up no more robust than its weakest component.