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  • R. Chakraborty added an answer in Biodiesel:
    How do you dope metal on activated carbon?

    I want to prepare a catalyst for biodiesel.

    R. Chakraborty · Jadavpur University

    The solubility of metal precursor in the solvent should be known to conduct proper precipitation/deposition impregnation . 

  • Jan Zukal added an answer in Bats:
    Can anybody provide information on the number and distribution of bat species in Toronto?

    Knowledge of the bat distribution is important to conserve their habitats.

    Jan Zukal · Institute of Vertebrate Biology

    Hi, you may check this publication about bats of Ontario. http://www.grwa.ca/mnr_docs/MNR%20Extension%20Notes/Habitat%20Managment%20for%20Bats.pdf

  • If any coordinates will do in General Relativity, is spatial curvature necessary? Is GR more complex than necessary, and is curvature verified?

    GR was introduced along with the principle that not only is no coordinate system preferred, but that any arbitrary coordinate system would do.  The complex mathematical machinery of covariance was introduced (including tensors) to express the laws of physics, any of the laws not just GR, in arbitrary coordinates.  This allows coordinate systems in which the distances vary with position and orientation, and in which the speed of light is non-isotropic (varies by direction), and such coordinates are routinely used in famous solutions such as Schwarzschild.

    So, it is not just the curvature of Riemannian geometry that requires complexity, but most of it is required by independence from coordinates.  And if indeed physics is independent of coordinates, can coordinates be found for solving GR problems in which space (if not spacetime) is flat and therefore graspable to the ordinary intuition?

    For an introduction to analysis of orbits using only time dilation, not  spatial curvature, see paper linked below.  GR was derived from the equivalence principle on the assumption that curvature was the only way to explain equivalence, but this is an argument not a proof according to GR verification authority Cliff Will.  If another method is available, it becomes a weak argument.  Is there empirical proof of curvature?

    Charles Francis · Jesus College, Cambridge

    It won't get you very far Robert! The reason is that in gr the special relativistic dilation contraction effects are simply absorbed into coordinate transformations and thereby are explicitly made illusory. You can talk about the distortion of maps, not about the distortion of real lengths.

  • Akram Mirlohi asked a question in Hydrogen Isotopes:
    Hydrogen isotope system in gneiss and granite as well as their biotites δD values?

    Dear researchers

    I follow the differences between hydrogen isotope system in gneiss and granite as well as their biotites δD values. Could you help me?

  • Hans H. Bass added an answer in Social Security:
    Do you know any literature or research on self-employed professionals and social security in Europe?

    I'm working on self-employed professionals and social security in Germany. I'm interested in how self-employed entrepreneurs make a living and how they think about social security (unemployment insurance, pension insurance, health insurance). Do you know any literature or research on self-employed professionals and social security in Europe (especially qualitative, ethnographic or biographical research)? Thanks in advance!

  • Does anybody have published work on the availability of water and economic growth/ development?
    I am looking for a correlation between availability of natural resources (water) and increases in agricultural/industrial productivity.
    Zarema Akhmadiyeva · Suleyman Demirel University

    Hello, I am interested in this topic as well. My case is Central Asia. Did you find anything?

  • Dr. Nizar Matar added an answer in Diving:
    What would you say are the factors in the classroom that most positively effect student success?

    I am wanting to dive into research about the classroom factors or pedagogies that can effect student success in a class.  What have you found in research or in practice? 

    Dr. Nizar Matar · An-Najah National University

    In practice, the factors in the classroom that most positively effect student success are mainly rational & psychological. The student must know the value of the subject s/he is learning in terms of its applications in life. The student ought to realize the shouldered responsibility towards self, family, and nation who are waiting earnestly for her/his success. The teacher ought to know how to encourage & raise morals : sometimes the simple word (Bravo) for a good answer can do wonders; I saw cases in my long career in which the student improve generally when I write next to the 18 to 20 marks (out of 20) the word (Excellent). The youth, we teach, are highly sensitive & do not like orders or harsh words so it is better to show them respect & to win their affection for the sake of their educational progress "which is really good for all".  

  • Joanna J Bryson asked a question in Hate:
    How do you delete a request for a PDF from Reserach Gate?

    I know RG hates it when you ask about them here, but their "feedback" link is broken so…I emailed a PDF to someone directly rather than uploading it through RG.  They've written back & I know they have it, but now I'm still getting RG SPAM asking for the PDF.  How do you turn off  a query?  I'm happy to email copyrighted PDFs to individuals, but not to upload them through RG,

  • Frederick Crane added an answer in Phytochemistry:
    Who knows the Rf of Onopordopicrin on silica TLC? (+ mobile phase composition)

    I am looking for the isolation of onopordopicrin from some Onopordum species, please provide me the RF of silica TLC and mention the used mobile phase.

    Frederick Crane · Purdue University

    sorry i dont the answer F Crane

  • How to get bond properties of moleculars except for software PETRA?

    In a paper, seven bond properties were calculated  by PETRA 3.20: resonance stabilization, the difference between the σ electronegativity of the two atoms, etc. But PETRA is not free any longer.

    Damjan Temelkovski · University of Westminster

    Hi Xiang,

    I know that obprob from OpenBabel gives basic properties for molecules, but I suppose you need more complex properties.

    It seems like you can use a 'restricted version of PETRA'

    or if you want to see properties for a single molecule there is this application that needs the molecule in a SMILES format, which I know obprob provides:



  • Hans H. Bass added an answer in Project Development:
    Are there any readings about how entrepreneurship creates development?

    I need some readings and literature, especially theories about the causal relationship of entrepreneurial projects and development.

    Skipping the economic development since it would be complicated to argue.

  • Roberto Köferstein added an answer in DTA:
    How do you change the TGA data to DTA?

    I would appreciate any relevant literature suggestions to change the TGA data to DTA without running the DTA if it possible.

    Is there any problem I will face?

    thanks a lot

  • Johan J. Sánchez added an answer in PET:
    Is it possible for PET bottles to be soluble in solvents?

    Pollution by PET (polyethylene terephthalate) bottles is a major threat to the localized environment almost throughout the world. 

    a) Are there alternatives to these PET bottles?

    b) Is the PET scrap soluble in any solvents?

    c) Is anyone an expert in this field of PET bottles and their chemistry?

    d) Is it possible to use this PET as a raw material for the production of other chemicals (polymers), as fuels etc?

    e) Is there scope for change in the characteristics of the PET bottle so that something can be thought to minimize the Impact of these PET bottles being used for various appliances?  

    When I drank RO water stored for a week in the same PET bottle (intentionally), it took a couple of days to recover. A feeling of gastric irritation, giddiness and a hatred for water was developed.  

    What biochemistry could have happened then? 

  • Claudia Viegas added an answer in Policy Modeling:
    How is "sustainable regional development" approached in your country?

    I am looking for experiences and publications addressing policies, models, methodologies and instruments used.

    Claudia Viegas · Universidade do Vale do Rio dos Sinos

    Hi, Isabel

    Unfortunately we have few comprehensive studies on regional development. We actually have more statistics than analysis or interpretative studies. Regional studies, at least in my region (Southern Brazil) are limited to assess economic growth, average income of population, aging, some aspects of public health - as average life expectancy and childhood mortality, and educational aspects (literacy). I am aware that such data do not mean a robust approach for regional sustainable development. Although we have recent grey literature on mobility, sanitation, water and wastes' collection services available in some municipalities (mainly from urban observatories), we have no culture for a critical assessment of regional sustainability as a public policy. I have read some studies about it in UK and US. In my point of view, the best way to tackle such complex issue is through Health Impact Assessment.

  • Who has Pseudomonas syringae pv. tomato DC3000 (Pst) bacteria?

    I want Pseudomonas syringae pv. tomato DC3000 (Pst) bacteria to inoculate the arabidopsis!

    Mesrop Ayrapetyan · University of North Carolina at Chapel Hill

    Contact the authors of this paper, I'm sure they would gladly provide it. 


  • Qianfeng Wang added an answer in Crop Yield:
    What are the methods for crop yield estimation based remote sensing?

    I want to find several methods in crop yield estimation( especially winter wheat yield estimation) using remote sensing data. 

    Qianfeng Wang · Beijing Normal University

    Thank you very much for your suggestion.

  • Is it possible to use the impervious surfaces (such as buildings, roads, etc) as indicators of environmental sustainability in urban settings?

    Impervious surfaces show the intensity of urbanization on the natural environment. Can we say that environmental sustainability decreases with the increase of impervious surfaces?

  • Are matrices of Boundary Elements Method invertible?

    I'm working on matrices arisen from collocation BEM, so I'm looking for a reference about them. Also I know matrices of Galerkin BEM is invertible but I don't know a way! Is there any draft about it?! 

    Hady Joumaa · University of Illinois, Urbana-Champaign

    Dear Vincenzo,

    Solving a linear system [A]{X} = {B} means to find the unknown {X}. It has nothing to do with inverting the matrix [A], even though inverting [A] is one method to solve the system, and it is actually the worst one!

     In addition, the LU factorization is not correlated to matrix inversion. The LU factorization helps solving the linear system by solving two triangular systems. It has nothing to do with matrix inversion, On top, the LU factorization cost is n^2 log(n), but the matrix inversion costs n^3, where n is the size of [A]. That's is why matrix inversion is the worst choice of solving a linear system and it rarely if not never used.

    Hope my remarks clarify your misconceptions.   

  • Simon Tam asked a question in Liposomes:
    Cholesterol from animal sources is used to produce liposomes. Are there any potential threat?

    Cholesterol from animal sources is used to produce liposomes.  Are there any potential threat?  If so, what are these threats?

  • Lukasz Plociniczak added an answer in Cosmology:
    Can the initial singularity be removed from cosmology models?

    In a rather old paper, Michael Heller argues that in certain cases it is possible to remove the initial singularity from cosmology models. He discusses b-boubdary and noncommutative geometry. So what do yo think?

    Lukasz Plociniczak · Wroclaw University of Technology

    Dear Victor,

    I reckon that some theories with varying physical constants can remove many kinds of singularities such as Big Bang, Big Rip and other, exotic singularities. The question is of course with the correctness of those theories and whether such constant as speed of light (which is dependent on the chosen units) can vary in some consistent way. If interested, please see the attached paper.

    All the best,


  • Yordan Muhovski added an answer in Primer Sequences:
    Which primer is preferable for sequencing: M13 (-21) or another one?

    I have a question in choosing primers for sequencing. Which one is preferable: using only M13 (-21) or sp6 and T7 forward and reverse primers, respectively? As I don't know the orientation of my insert, I'm likely to amplify the complementary to my insert than the insert itself if I use only M13 (-21) which could result in taking complementary sequence for annotation. How can I solve this limitations in using single (only forward) primer (M13-21)? I think I have to use sp6 and T7 as either of the two surely amplify my insert as the amplification occurs in both orientations. My vector was pGEM-T easy.

    Yordan Muhovski · Walloon Agricultural Research Centre CRA-W

    I am using pGEM-T easy and  I use T7 and sp6 to sequence my fragments  and they are working perfectly.

  • Arseniy Yuzhalin added an answer in Western Blot:
    Hi there, I am having difficulty in doing western blotting of MBL serum protein. I would appreciate if someone could share detail protocol for WB ?

    I am using 1:10 dilution of serum sample after heating for 5 minutes at 99C.

    Arseniy Yuzhalin · University of Oxford

    try this protocol:


  • Manish Kumar asked a question in Cobalt:
    Can we doped cobalt (at Fe site) and lanthanum (at cobalt site) in CoFe2O4 ?

    It is related to structural properties.

  • How do I use amber to add NaCl?

    Hi, everyone

      I want to simulate a biomolecular system with certain ionic strength using amber software, but the tutorial did not tell me how to add NaCl using tleap. Someone told me to use this command "addions REC Na+ 5 Cl- 5". And another one told me to use" addions REC Na+ 1 Cl- 1

       addions REC Na+ 1 Cl- 1

       addions REC Na+ 1 Cl- 1

       addions REC Na+ 1 Cl- 1

       addions REC Na+ 1 Cl- 1". That is, it has to add the ions one by one. So, which one is right, or whether neither is right? Can anyone give me some suggestion?

    Najme Dehghan · Tarbiat Modares University


    you could use Tleap or Xleap program to solve your problem


  • Ehsan Esmaelian added an answer in Ship Design:
    What is the method for calculating dimensions and position of boat trim tabs?

    I want to investigate about the boat trims tab and interceptors. Trim tab and Interceptor are used for improving lift in the boats for example planning hulls.

    Thanks in advance.

    Ehsan Esmaelian · Amirkabir University of Technology

    Hi sam, hydrodynamic

  • How do you prevent PBMC protein degradation?

    After my western blotting for TBP in PBMC, I saw no bands for 2 samples which may be due to protein degradation. I have kept the two samples for 4 months in -20C with protease inhibitor cocktail (Roche). Any suggestions? Thanks very much.

    Arseniy Yuzhalin · University of Oxford

    That must be okay. Protein degradation isn't` really a case, because you willingly denature your protein before western blot using DTT.

  • Ajay Singh added an answer in Groundwater Quality:
    What is the best option for manging the environmental problem of seawater intrusion in coastal areas?

    The seawater intrusion is a widespread environmental problem of coastal aquifers where more than two third of the world’s population lives. The indiscriminate and unplanned groundwater withdrawal for fulfilling the growing freshwater needs of coastal regions causes this problem. Seawater intrusion is one of the major causes of groundwater quality degradation because mixing even a small quantity of 2-3% saltwater makes the groundwater unsuitable for domestic, agricultural, and industrial uses. What is the best way of managing this problem?

    Your response is very much appreciated.

    Best regards,

    Ajay Singh · IIT Kharagpur

    Thanks Dr. Mitra for your time in responding my question.

    Best regards,


  • Is it possible to calculate wavelength dependent complex refractive index of thin films using absorption spectra?

    I'm working on modelling organic solar cells and need to find the complex refractive index data of common active layer polymers and charge extraction layer material.

    Shashikant Sharma · Malaviya National Institute of Technology Jaipur

    To Tsvetanka Babeva :  Please suggest me how wavelength dependent  refractive index for thin films can directly be calculated if value of transmittance, absorbance and film thickness is known.