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  • Zahrah J Alnakhli asked a question in Drug Carriers:
    What the point, measuring mass susceptibility of magnetic nanoparticles, what information this property is going to tell us about its use in medicine?

    Now I made tow types of magnetic nanoparticles. I want to compare there magnetic properties in order to conclude the advantages and disadvantages of using them as drug carriers. I would like to Know  What the point of measuring mass susceptibility of magnetic nanoparticles that will be used for drug delivary applications?  what information this property is going to tell us about its use in drug delivery applications?

  • Arvind Singh added an answer in Plants:
    Can anyone help me in identification of this plant species?

    Location: Coastal area of Gujarat, India

    Arvind Singh

    The plant seems succulent xerophyte of Euphorbiaceae or Crassulaceae family

  • Katheem Kiyasudeen asked a question in Earthworms:
    How do we justify using triplicates when working on living organisms like earthworms?

    Studying living organisms always pose difficulties. Usually triplicate study is employed when studying in general. Past researchers have done the same. When asked why 3? not 5? not 7?. What would be our justification?. Kindly share all your suggestions and literature back up. This might enlighten many.

    Thank you,



  • Katharina Kubicek added an answer in Density Functional Theory:
    Any suggestion why in a geom opt DFT calc for a Cu(I)-complex the geom converges but the freq not, but when substituting phenyl with H freq converges?

    I am performing a geom freq DFT calculation with the G03 package on different heteroleptic Cu(I)-complexes with one Bis[(2-diphenylphosphino)phenyl] ether (DPEPhos) ligand and varying second ligand, phenathroline, pyridine and similar ligands. The geometry optimization always converges but the frequency calculation at the optimized geometry gives only convergence for the forces not the displacement. I get NO imaginary frequencies and running a geom opt with the calcall command on the structure of the previous opt freq calculation gives also no convergence for the frequency. However, when I substitute the four pheynl groups at the DPEPhos ligand with H atoms, I get convergence also in the frequency calculation (see attached structures). I don't understand what the problem with the phenyl groups is and what to do in order to achieve convergence in the freq calculation for the compounds?

    The input for the compounds is:

    #P B3LYP/LANL2DZ Opt Freq=NoRaman gfoldprint pop=full formcheck

    CuphenPOP LANL2DZ Molekel

    1 1

     I perform and opt freq calc and then at the optimized geometry using the checkpoint file from the opt freq calculation a calcall calculation:

    #P B3LYP/LANL2DZ Opt=CalcAll Freq=NoRaman Geom=AllCheck Guess=Read gfoldprint pop=full formcheck

    With the phenyl groups I get this output after the freq calculation:

    Low frequencies --- -6.0179 -2.2307 0.0005 0.0009 0.0010 3.7862
    Low frequencies --- 7.8641 11.7632 15.4691
    Diagonal vibrational polarizability:
    124.3077904 52.8075211 113.8823113
    Harmonic frequencies (cm**-1), IR intensities (KM/Mole), Raman scattering
    activities (A**4/AMU), depolarization ratios for plane and unpolarized
    incident light, reduced masses (AMU), force constants (mDyne/A),
    and normal coordinates:
    1 2 3
    A A A
    Frequencies -- 7.3431 11.2067 15.3067
    Red. masses -- 5.9950 5.2088 6.0434
    Frc consts -- 0.0002 0.0004 0.0008
    IR Inten -- 0.1901 0.0183 0.4275

    Item Value Threshold Converged?
    Maximum Force 0.000361 0.000450 YES
    RMS Force 0.000057 0.000300 YES
    Maximum Displacement 0.316848 0.001800 NO
    RMS Displacement 0.060707 0.001200 NO
    Predicted change in Energy=-8.661564D-05

    and with phenyl substituted by H:

    Rotating derivatives to standard orientation.
    Dipole = 1.51776480D+00 1.56759125D-01 4.17815692D-01
    Polarizability= 4.02814584D+02-1.31586962D+01 3.68441420D+02
    8.69063669D+00-3.81612415D+01 2.36612166D+02
    Full mass-weighted force constant matrix:
    Low frequencies --- -6.8423 -0.6698 -0.0006 -0.0003 0.0004 2.6307
    Low frequencies --- 10.0913 18.0893 21.7442
    Diagonal vibrational polarizability:
    58.7865711 38.2904911 54.5692058
    and normal coordinates:

    Item Value Threshold Converged?
    Maximum Force 0.000001 0.000450 YES
    RMS Force 0.000000 0.000300 YES
    Maximum Displacement 0.000433 0.001800 YES
    RMS Displacement 0.000110 0.001200 YES
    Predicted change in Energy=-2.290532D-10
    Optimization completed.
    -- Stationary point found.

    I used also different basis sets:

    b) #P B3LYP/GEN PSEUDO=READ Opt Freq=NoRaman gfoldprint pop=full formcheck 

    P O N C H 0
    Cu 0

    Cu 0


    P O N C H 0
    Cu 0

    Cu 0

    and the same result, so I am assuming it is not a problem with the basis set.

    Any suggestions would be highly appreciated.

    Thank you!

    + 1 more attachment

    Katharina Kubicek

    Thank you for all the answers, I appreciate them, I will try your suggestions and see if I can solve the issue this way.

  • Avinash Kumar Chouhan asked a question in Gravity:
    Satellite gravity data can be used for source depth estimation using power spectra methods??

    I want to calculate moho depth and I have only satellite gravity data. Does satellite gravity data give good result?

  • C. Phaniraj added an answer in Martensite:
    Why twinning occurs in some specific range of SFE values (18-45 mJ/m2) ?

    Whereas, at lower SFE values martensitic transformation, can be seen during plastic deformation of stainless steels.

    C. Phaniraj

    1) You may know that SFE has influence on the dislocation substructure; high SFE (smaller separation between partial dislocations) promotes cross-slip resulting in wavy dislocation substructure, whereas low SFE (larger separation of partials) inhibits cross-slip resulting in planar slip or planar arrays of dislocation structure. 

    2) In addition to its effect on dislocation structure, SFE also influences the propensity for the formation of deformation twins and low SFE favors twinning.

    Your Query:- 3) Though twinning is reported to occur at SFE roughly at a range of 18–45 mJ m−2,  martensitic transformation can be favored at SFE less than 18 mJ m−2, and glide of dislocation would occur when SFE exceeds 45 mJ m−2. Please see the paper "Twinning and martensite in a 304 austenitic stainless steel", Y.F. Shen et al., Materials Science and Engineering A 552 (2012) 514– 522. Please see the link in RG:- https://www.researchgate.net/publication/234154016_Twinning_and_martensite_in_a_304_austenitic_stainless_steel

    4) This paper may be useful to you:- "The Influence of Stacking Fault Energy on the Mechanical Behavior of Cu and Cu-Al Alloys: Deformation Twinning, Work Hardening, and Dynamic Recovery", AASHISH ROHATGI et al., METALLURGICAL AND MATERIALS TRANSACTIONS A, VOLUME 32A, JANUARY 2001—135.

    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: The microstructure characteristics and deformation behavior of 304L stainless steel during tensile deformation at two different strain rates have been investigated by means of interrupted tensile tests, electron-backscatter-diffraction (EBSD) and transmission electron microscopy (TEM) techniques. The volume fractions of transformed martensite and deformation twins at different stages of the deformation process were measured using X-ray diffraction method and TEM observations. It is found that the volume fraction of martensite monotonically increases with increasing strain but decreases with increasing strain rate. On the other hand, the volume fraction of twins increases with increasing strain for strain level less than 57%. Beyond that, the volume fraction of twins decreases with increasing strain. Careful TEM observations show that stacking faults (SFs) and twins preferentially occur before the nucleation of martensite. Meanwhile, both {var_epsilon}-martensite and {alpha}{prime}-martensite are observed in the deformation microstructures, indicating the co-existence of stress induced- transformation and strain-induced-transformation. We also discussed the effects of twinning and martensite transformation on work-hardening as well as the relationship between stacking faults, twinning and martensite transformation.
      Materials Science and Engineering A 08/2012; 552. DOI:10.1016/j.msea.2012.05.080
  • Philip Barlow added an answer in Crop Yield:
    How are different nutrient interactions important for crop yield and quality?

    It is now abundantly clear that nutrients play an important role at various levels of plant s structural as well as metabolic developments. While studying the importance of different nutrients , there are often overlappings in functionality of different nutrients, popularly known as NUTRIENT INTERACTION. Such nutrient interactions more than often , either go un-noticed or overlooked on account of absence of information  with respect to a specific crop. Different querries pertain to importance of nutrient interactions . You have been hugely courteous in responding to my all querries in the past . Below is  my latest post . I humbly request to my learned friends to express their opinions.

    * Whether nutrient interactions are growth stage - and crop dependent ?

    * Can we characterize the nutritional properties of a crop, based on variation in different nutrient interactions cross growth stages? 

    *How are nutrient interactions and nutrient-use-efficiency inter-related?

    * Whether  a particular  nutrient interaction influencing  crop yield, will influence the   quality  as well or its different ?

    * Do we consider nutrient interactions while recommending fertilizer doses?

    Philip Barlow

    Add up all the nutrients in a leaf analysis and the result will be less than 10%, the remainder is not water because values are reported on a dry weight basis. The main elements not reported will be O,C,H (Products of photosynthesis) and there will be a little Si & other elements there also. Data related to this unreported fraction has value to interpreting leaf analysis for when we get the correct balance of required nutrients (NPK etc) with no excesses or deficiencies then the Nutrient / filling value ratio is low. The leaf is therefore operating with efficiency. No weighted means required.

  • Narayanan Nair Mohanan added an answer in Shrubs:
    Can anyone help me in identification of this plant species?

    It is a much branched small tree or rather shrub. The leaves are simple and petiolate, and the phyllotaxy is opposite with decussate leaf pettern

    + 2 more attachments

    Narayanan Nair Mohanan

    Dear Aravind

    It is not easy to  identify plants from photographs, that too when they are without flowers or fruits.  You may please check the plant is having a milky latex . All Ficus are with latex and the leaf bud covered by a foliaceous bract.  F. hispida is the only Indian species having an opposite decussate phyllotaxi. But F. hispida has a very rough hispid leaves. See whether there is latex.

  • Pranav Tiwari added an answer in Nanofluids:
    How accurate is the particle size measurment using DLS for graphene nanofluids?

    I have prepared stable kerosene-graphene nanofluids and measured particle size distribution by DLS measurement (Zetasizer ) with days. Is the technique reliable for non spherical particle size measurement?

    Pranav Tiwari

    I don't think this technique is reliable for  size measurment for non spherical particle because the basic mechanism behind the DLS size is the formation of the virtual sphere. Although this technique is useful for PdI measurment and zeta potential for colloidal stability.

  • Negin Malekian added an answer in Ductal Carcinoma:
    Why do ordinary differential equation (ODE) models of cancer suggest different behaviors for cancer cells?

    For validation part of my study, I need a comparison between my model of ductal carcinoma in situ (DCIS) and ODE models of this area. But, I’m really confused because ordinary differential equation (ODE) models of cancer have suggested different behaviors for tumor and immune cell populations. For example, the below behaviors are reported by the survey of Eftimie et al. (2011) [1]:

    • Tumor size decreases exponentially through interactions with the immune cells.
    • Tumor size decreases at first. Then, the decay of immune cells leads to an exponentially increase in it again.
    • Tumor size decays in an oscillatory manner.
    • Tumor size grows in an oscillatory manner.

    I don’t understand the reason of the difference! And, I don’t know which behavior is right. Could anyone possibly help me, please?


    [1] Eftimie, Raluca, Jonathan L. Bramson, and David JD Earn. "Interactions between the immune system and cancer: a brief review of non-spatial mathematical models." Bulletin of Mathematical Biology 73.1 (2011): 2-32.

    Negin Malekian

    Thanks everyone,

    Actually, I want to know which behavior tumor cells would show through interactions with the effector cytotoxic T cells (CTLs)  (i.e., an exponentially decrease, an exponentially increase, an oscillatory decrease, an oscillatory increase, or some thing else). Do you think I can fit my model with Gompertz curve?

  • Anju Mundhe asked a question in Trizol:
    Any protocol for DNA isolation with trizol from gill tissue?

    I have tried phenol-chloroform-iso amyl protocol. But the quality of DNA is not good enough to run PCR. Now trying for trizol protocol.

  • Francesco Argese added an answer in Virtual Reality:
    Is there anyone interested in a research collaboration towards 2-3 publications on the theme of VIRTUAL REALITY AND IMMERSIVE WORDS in Academia?

    I am researching the impact of these technologies to new learning systems in academic settings

    Francesco Argese

    I'm working on a project involving the use of Virtual Reality and Augmented Reality in a learning environment and I could be interested. You can contact me through a message on Research Gate.

  • Murad Mohamed Burondkar asked a question in Machines:
    Can any body suggest a portable scanner for the detection of spongy tissue or any other internal disorder in mango or any other fruits ?

     Occurrence  of Spongy Tissue (  internal  breakdown of fruit pulp) in  mango Cv. Alphonso, is one of the serious physiological disordesr, badly impairing the fruit quality and thus  market reliability of this prime export Indian mango  variety.  Apparently, both healthy and affected fruits looks a like and cannot be distinguished between, unless fruit is cut opened. Several studies have been  concluded to find out the cause and remedy, but  breakthrough yet to come. Till then, one of the approaches  is to have portable scanner for accurately detecting the presence of disorder before fruits are packed for marketing. We  could able to use the soft X ray based  machine with great success but size of the machine is major limitation for handling, Hence looking for  hand held, portable scanner as most suitable option 

  • Tolga Zorlu asked a question in Nanotoxicology:
    Which parameters can appy in nano-QSAR methods?

    Dear scientists

    Nano-QSAR methods are relatively new branch of nanotoxicology. There are so many differences and a little similarity when compare to classical QSAR methods. I want to ask that which parameters can apply in nano-QSAR methods. I know that size, surface area or other spesific values can affect the nanomaterial toxicology. However, is there a standart algorithm for nano-QSAR?

  • Anamika Singh asked a question in Tris Buffer:
    During activity measurement of DAHP synthase , the OD of PEP without any enzyme or co-substrtae (Phosphoenolpyruvate) was not constant. suggestions?

    The enzyme catalyses the first reaction of shikimate pathway .
    Phosphoenol pyruvate + erythrose 4 pohosphate gives DAHP + Pi

    Experiment set up: we are measuring the decrease in absorbance of PEP at 232 nm with time due to formation of DAHP , and consumption of PEP.
    1. Reference – Buffer only ( Bis -Tris buffer 50mM 7.5 pH)
    2. Pep (100uM)+ E4P(300uM) + MnCl2 (100uM)+ buffer ( but no stable reading)
    3. Pep + E4P + MnCl2 + buffer + enzyme added and with different time interval reading took but in this case also there was continuously increase in absorbance at 232nm.
    Ideally there should be decrease in absorbance of PEP at 232 nm with the time. It was continuously increasing, and after adding enzyme it was also increasing.

    on the other hand  when I started taking reading of PEP in absence of ENZYME it was not stable, continuously increasing.Ideally it should be constant if not participating in any enzymatic reaction with its co-substrate or enzyme.

  • Mohamad Ivan Fanany added an answer in Data Mining:
    Can any one give the list of computer science free journal names/links which are indexed by Scopus/IEEE/ACM/Elsevier?
    This may help us to publish our work on high impact factor journals.
    Mohamad Ivan Fanany

    In case of Hindawi, most of Hindawi's Journal does not have impact factors. For such Journals, the open access publication fee might cost us USD 600 - 800 and some even free. When they do have impact factor, however, they cost USD 2000. I wonder why they charge us (as authors) more, where in fact the authors are the ones that have helped them to get their Journals got the impact factors (smile) ? I think it would be better to provide discount for authors that already publish their work in the Journals (just my two cents).

  • Asa Wu asked a question in Tris Buffer:
    Does pH of Tris Buffer change after diluted in distill water?


    Does pH of Tris Buffer change after diluted in distill water? for example, I have 5M Tris buffer ph 6.8 and dilute with distill or molecular grade H2O to 1M Tris buffer. Does the ph of this 1M tris buffer still ph 6.8?

    Thank you

  • Maria Lazăr added an answer in Environmental Impact Assessment:
    Does it is better to develop new tool for environmental management rather than Environmental Impact Assessment (EIA)?

    Environmental impact Assessment tool used in worldwide since 1980s, has found major implications for sustainability of the project and protection of surrounding environment. In past climate change issue was not addressed in EIA process. Now the tool is not complete all issues addressing natural impacts. So does it is better to integrated some methods of EIA in new tool combining SEA and climate change?   

    Maria Lazăr

    Typically, the environmental impact assessment (EIA) is used to study the chain effects (changes in the environmental evolution in time and space) generated by certain anthropogenic projects. Obviously, climate changes have a major contribution to changing of the environmental conditions, but their effects are analyzed using simulation and forecasting tools. Do not exclude the possibility of developing a new assessment tools that take account of both forms of environmental degradation.

  • Asa Wu asked a question in Tris Buffer:
    Does pH of Tris Buffer change after diluted in distill water?



    Thank you

  • Abdulnaser Ibrahim Nour added an answer in Corporate Governance:
    Is their  any relation between risk governance and corporate governance?

     I want comments if their is The relation between corporate governance and risk governance.

    Abdulnaser Ibrahim Nour

     Dear Pieter thanks a lot for your comments and explanation.

  • Jaafar Mohammed added an answer in Vibration Engineering:
    What is the best handbook in vibration problems (seismic measurements in geotechnical engineering)?

    damage to segment tunnel resulting from seismic load or seismic load effect on tunnel lining

    Jaafar Mohammed

    Dear Mr. Mohammed Abu-Hilal , Thanks a lot for you , I got this one " Cyril M. Harris and Allan G. Piersol, 2002,HARRIS’ SHOCK AND VIBRATION HANDBOOK - Fifth Edition"

  • Dheeraj Kumar added an answer in Materials:
    On what basis we classify the material as isotropic, anisotropic and homogeneous etc.?

    A material is isotropic if its mechanical and elastic properties are the same in all directions. When this is not true, the material is anisotropic

    How will we decide directions of properties in a material?

    Dheeraj Kumar

    Dear Suresh, Rudy, Vijay,

    Thanks a lot for your valauble answers..!!

    My qusestion was related to all mechnical properties of the material. I have got the clarity to some extent. I have changed the question for more clarification.

  • Asina Bayram asked a question in Lysis Buffer:
    What is the best human red blood cell (RBC) lysis buffer to deal with RBC contamination after TESA?

    Human Embryology

  • Michael Päch added an answer in Laser Spectroscopy:
    Does anybody know about a european supplier of acetylene and ethyne isotopes?

    It seems that there no exists a supplier of the 13C2H2 and 12C2H2 acetylene isotopes in Europe. We and our colleagues from laser standards branch need these gases for the laser spectroscopy research. China manufacturers can not ship these materials due to some government restricitions (dangerous material), overseas shipping from USA is extremelly expensive (air post is not possible - flammable materials). Is it possible to prepare these materials on request at some European facility? Thank you a lot!

    Michael Päch

    Hi, Jan,

    what do you mean by clean isotopes? Your original post was about how you could get some 13C2H2. Now I have presented you a method to synthesize it quite easily from a comparatively cheap source of 13C and you are asking how clean isotopes can be made by this method? I'm puzzled...

  • Katrina Leslie asked a question in Anther Culture:
    What is currently the best callus induction medium for anther culture of indica rice type?

    Based on the current results of different studies on anther culture of indica rice, do you have any idea what is the best callus induction medium? What about the response of callus induced from this medium in terms of green plant regeneration. 

  • Abdullah Aamir added an answer in Multilevel Inverters:
    How can I create a circuit for pulse generation using sine-triangle pwm for multilevel inverters in matlab?

    I'm actually working on a new topology of an 11-level inverter. I want to implement it using SHE-PWM or SVPWM, but initially i want to simulate it using sine-triangle pwm....I'm quite new to pwm techniques. Can somebody help me?

    Abdullah Aamir

    Dear Dr.Abdelhalim,

    Thank you for the explanation, but by fixed values, do u mean by constant blocks?Since i'm quite new to this field,i'm a bit confused. And i didnt find any clear explanations on how to implement sine-triangle pwm in matlab.

    Best Regards,

    Abdullah Aamir

  • Preet Shah asked a question in Interferon-gamma:
    Is it possible to have a false positive IGRA in a case of active Crohn's disease?

    Interferon Gamma Release Assay is a test done to detect Interferon-gamma release by lymphocytes sensitised to mycobacterium tuberculosis. Its a test often done to detect latent TB. Crohn's disease is an IBD, in which Interferon-gamma plays an important role. So since this cytokine is common to both, is it possible to have a false postive IGRA in a patient with active Crohn's disease? Especially in countries like India, where almost everyone has been either vaccinated (with BCG), or exposed to the tubercle bacillus at some point of time; but not everybody develops the disease.

    Please do give your inputs, with any references if possible.

    Thanks in advance !

  • Cyril Mechkov added an answer in Circuits:
    Can we call it a non-inverting summing amplifier?

    Inverting summing amplifiers are well known. However, attached is a circuit with two versions. The first gives an output from the amplifier that is equal to the average value of three input signals. The second gives an output equal to the sum. The topology can be extended to higher inputs, but I cannot recall it being documented in text books on op amps. Can it be called as a non-inverting summing amplifier ?

    Cyril Mechkov

    "Increased noise gain" means "decreased loop gain"?

  • Yeething Lim added an answer in Solanum:
    What is the scientific name for this fruit from Solanum sp?

    Common name :

    Terung Asam, ripen yellow sour brinjal, smooth surface without hair, mostly found in tropical area, such as Sarawak, Malaysia, Indonesia.

    I found it is quite confusing where some claimed it is "Solanum ferox. L (Terung Asam group)" while others also claimed it is "Solanum aethiopicum".

    Yeething Lim

    This is the reference book I refer to. 

    pg 333. stated Solanum ferox = Solanum lasiocarpum


  • Gina Joue asked a question in Aggregation:
    How to deal with bad ex-Gaussian fit to RT distribution for only some conditions and some subjects?

    I used R's retimes::timefit to fit an exponentially modified Gaussian distribution to reaction time data. It estimates ex-Gaussian parameters based on maximum likelihood and gives AIC/BIC/log likelihood of the estimated parameters, but I would also like to check the goodness of fit. Can anyone point me to how to do this? But even if I do have a goodness of fit measure, I can already see that visually plotting observed RT histograms and the distribution curve with the estimated parameters, not all conditions for certain participants have great fit when an ex-Gaussian curve would seem like a good fit (and other times when it's clear from the distribution that an ex-Gaussian curve is not a good description, e.g. bimodal RT distribution). What do you do in these cases when it is only SOME of the conditions for SOME of the participants?

    I have collapsed across different conditions in my data for each participant because keeping all the conditions would result in too few data points for each parameter estimation, so I've run timefit for these different aggregated versions of my data and chose the aggregate version resulting in the lowest overall AIC/BIC. My second question is whether this is kosher? On the other hand, the estimations with the lowest AIC/BIC also seem to have the worst fit through visual inspection. The highest AIC but visually best fit are the estimations collapsed across participant, but I need estimations per participant....Thanks very much in advance for any help!