ResearchGate Q&A lets scientists and researchers exchange questions and answers relating to their research expertise, including areas such as techniques and methodologies.

Browse by research topic to find out what others in your field are discussing.

Browse Topics

  • Is there commercially available software for the simulation of copolymerization?

    Dear Colleagues

    Does anyone have experiece with commercially available sofware developed for simulating muli-component copolymerization kinetics, composition, viscosity, conversion etc. calculations? Looking forward to hearing from you on your experience regarding correctness and applicability. Gyorgy

    Marcelo Kaminski Lenzi · Universidade Federal do Paraná

    Dear Dr. Banhengy,

    I know the software Predici, which was developed by prof. M Wulkow, as a suggestion, please check the following link:  http://www.cit-wulkow.de/content/view/13/41/

  • Gurudeeban Selvaraj asked a question in Gromacs:
    How to install GROMACS?

    Can any one tell me how to install Gromacs in my personal computer 

  • Mohammad Ayaz Ahmad added an answer in Gelation:
    Why the temperature of incubation of cheese should be 35 degree Celsius?

    The incubation temperature significantly affected () cheese yield. Other authors have reported that increased incubation temperature during acidification causes the onset of gelation at higher pH values, obtaining a thicker gel more susceptible to spontaneous synergism during storage [1]. This effect may be attributed to a higher ratio of aggregation to disaggregating forces during the earlier stages of acidification owing to decreased casein dissociation from the micelles, a reduction in repulsive forces due to increased hydrophobicity, and faster rate of acidification

    Mohammad Ayaz Ahmad · University of Tabuk

    Please read the following web link.

  • Dharmesh J Bhalodiya added an answer in Sampling:
    Can anyone help me regarding Apriori algorithm enhancement ?

    I am not able to find Apriori algorithm with boolean matrix generation algorithm.CAn anyone provide me code for it?

    My second question is,using sampling technique ,if accuracy doesn't fall then,the algorithm with sampling of original algorithm can be called as enhanced algorithm??for my research?

    Dharmesh J Bhalodiya · Silver Oak College of Engineering & Technology

    Try to reduce no. time database scan... 

    another major improvement is : try to reduce size of  total candidates generated...

    if you interested than tell me we think about that...

    i hop.. this will helps you  

  • Which epidemiological and statistical approach do you apply, when you're studying Aspergillus development? Incidence study or Time Series?

    If we are taking daily samples to study Aspergillus development as surveillance in high complex hospital, which kind of epidemiological and statistical approach do you suggest to use: Time series or incidence study? The outcome is positive culture.

    Raid Amin · University of West Florida

    If there are also some unknown external factors that may have influenced the incidences in the hospital, I would also consider a spatial and space-time analysis of incidence rates by residence locations of the infected patients. Scan for clusters. I use satscan that can freely be downloaded at satscan.org.

  • We are looking for a mutual cooperation with a professor of a university inthe US or Europe. Are you interested?

    I am research engineer and team leader of 20 master students at the combustion and heat transfer lab of Iran university of science and technology which is a leading university in Iran. i am looking for a mutual cooperation with a professor of a university in Europe or US for publishing papers in the field of combustion of metallic dust cloud like iron, aluminum or etc. If you have interest in publishing papers and working remotely with our group, please contact me to expand our experience together.

    E-mail: alireza.poorfar@gmail.com

    Thank You

    Alireza Khoeini Poorfar · Shahrood University of Technology

    Sir  It is an honor to have a message from you Professor Goey .

    I think  Professor  shoshin and professor bidabadi are old friends from macgill university ,maybe it is a good idea to connect  our research groups to each other. Thank you Sir and have a merry chrristmas and have a good year doctor

  • Imran Khan added an answer in Myocardial Infarction:
    Do you have any experience with this pathology?

    Rupture of ventricular septum, Papillary muscle and free ventricular wall after myocardial infarction in the same patient .Did your patient survive? Usually these patients don't survive.

    Imran Khan · Punjab Institute of Cardiology

    James Wilson, Sir very nice comment. thank you

  • Janusz Pudykiewicz added an answer in MATLAB:
    How can I calculate this using Matlab ?

    How to integral different variable (s domain VS t domain ?)

    Janusz Pudykiewicz · Environment Canada

    Dear Gue-Ping:

    I have modified the code by adding the explicit functions for u0,y0,v0 in the functions fun_a and fun_b defining elements of the matrix A and the vector b.

    I have changed also the argument of the integrated function from s to t;  in this form you need to add only the explicit functions for u0,y0 and v0 as well as the function for M.

    The code with modifications is as follows:

    global Ifun Jfun
    global s

    % inset upper time limit
    % define parameters
    ni=3; nj=3; limit1=0; limit2=T;
    tol=1.0e-06;                     % you can set different value
    % set up function handles
    fhandle_a=@fun_a                 % elements of matrix A
    fhandle_b=@fun_b                 % elements of vector b
    % set A and b to zero
    A=zeros(n1,n2); b=zeros(n2);
    % evaluate A
    for Jfun=1:n2
        for Ifun=1:n1
    % evaluate b
    for Jfun=1:n2
    % solve linear problem


    % Functions ( they should be added as additional m files



    global Jfun Ifun
    global s










    global Jfun Ifun
    global s








     Please let me know if this code solves your problems.

    With my Best Regards,


  • Paolo Aseni added an answer in Pancreatic Cancer:
    What is a recent, modern and advanced treatment of pancreatic cancer?

    Surgical management.

    Paolo Aseni · Azienda Ospedaliera Niguarda Ca' Granda

    I also  confirm that the article of  Dr. Josè Ramia (Anna Pallissera is the first Author), which has recently appeared in World Journal of Gastromnterology on September 15 2014, is a very interesting article and is a valuable tool for discussion about pancreatic cancer advances (surgical treatment of  tumours of the haed of the pancreas). I have also found interesting among many reviews available in literarture  "Current Practice in Pancreatic Surgery" by Philippe Bachellier  in the section "Liver and Pancreatic Diseases Management" Advances in Experimental Medicine and Biology by Springer ed.  Volume 574, 2006, pp 111-143 which is dedicated only to different  aspects of surgical techniques.

  • John Burrett added an answer in GraphPad Prism:
    How I can draw this kind of graph?

    I want to draw such a kind of column for marine benthos. how i can draw it. is it possible to draw it with Excel or Graphpad Prism? 

    John Burrett · Haiku Analytics Inc

    Hi Mohammad

    That's easily done with Tableau, using the same column and row variables and specifying the variable (e.g. species) that would generate the separate sections.  Or you could just use Excel and cut and paste separate graphs together.

  • Fatima Zahra Harmouch asked a question in IEC:
    What is most appropriate standard for microgrid IEC 61850 or IEC 60870?

    IEC 61850 is a standard for substation automation, and IEC 60870 is a standard for telecontrol implemented in SCADA systems. I want to know what is the most appropriate to use in a small microgrid? and what are differences between both of them?

    Thank you,

  • İhsan Basaran asked a question in Tin:
    Can Tin(II)chloride turn into tin(II)chloride dihydrate when it is simply exposed to atmosphere ?

    Is it possible to obtain SnCl2 dihydrade from SnCl2 without any special treatment ?

  • Hana Shaker added an answer in FPGA:
    What is a suitable approach to implement a face recognition system on FPGA?

    My project is face or object recognition in images using FPGA. Can anyone suggest a suitable approach to implement the project i.e. directly with HDL programming or first in MATLAB programming and thereafter converting the MATLAB program to HDL by using the code converter. And please provide the material regarding the project?

    Hana Shaker · Zagazig University

    Useful link:


  • Anuradha Krishnan added an answer in ALP:
    What is the cause of a high level of alkaline phosphatase (ALP) in hepatotoxic-induced animal models?

    I'm keep getting higher ALP serum levels in the control, untreated group compared to the treated ones, is there is any explanation for this?


    Anuradha Krishnan · Mayo Foundation for Medical Education and Research

    What was your 'vehicle' control?

  • Negitive value of Cronbach's Alphaa?

    by using brief measure of big five personality inventory consist of 10 items SPSS is showing  Reliability Statistics Cronbach's Alphaa= -.066 (Note= The value is negative due to a negative average covariance among items. This violates reliability model assumptions. You may want to check item codings.).

    kindly help me how I can resolve this problem or interpret it.

    for refence output file is attached

    Michal Hajdúk · Comenius University in Bratislava

    I can`t open spv file in my SPSS. So look at table with item-total correlation. Have some items negative item-total correlation? Did you recode reverse score items?

  • What is the best possible way to model a Semiconductor Ring Laser Gyroscope system?

    I want to model a semiconductor ring laser gyroscope mathematically. What is the best possible way to do it.?

  • Behrouz Ahmadi-Nedushan added an answer in publishing researches:
    How to find a suitable journal to publish your work?
    To avoid any loss of time by submitting manuscripts to inadequate journals, in this websites you can try finding out the best solution.


    Behrouz Ahmadi-Nedushan · University of Yazd

    mportant tips before choosing a journal (From Elsevier):

    • Read the aims and scope of the journal
    • Read or download Guide for Authors
    • Check if the journal is invitation-only as some journals will only accept articles after inviting the author
    • If you need to publish open access know that most Elsevier journals have open access options explained on the journal homepage
    • Submit your paper to only one journal at the time
    • Check the journal performance for the review and publication timelines
  • Zinkar Das added an answer in Smell:
    Can anyone know about transfer of smell through wire/wireless medium?

    Smells are Basically a chemical reaction with various chemical molecular perspective. But anyone can any ideas of transferring it through wire/wireless medium for enhancing the scope of virtual reality?

    Zinkar Das · Bengal College of Engineering and Technology

    Oh Thank you. I was working on it. I made a device from that you can get the smell of an computerized image.

  • Azadeh Tabatabae asked a question in Activism:
    What difference is there between the catalytic activity of CoO and Co3O4?

    which Catalytic activity is better?

  • Coen Maas added an answer in Ficoll:
    PRP (Platelet-rich-plasma) isolation protocol?


    Hopefully, someone can please help me out with my misunderstandings surrounding prp. I have been told that the standard protocol for prp Iisolation from whole blood is 160xG for 15 minutes. This is easy enough, however what I am unclear on is which layer to take! I seems easy enough, but I keep seing pictured and videos of only three layers, then some with more than three layers. The last time I asked about prp isolation, someone gave me the same protocol and said to aspirate the supernatant, being careful not to extract the white blood cells.

    Please let me provide some pictures and you tell me which will be the product of the protocol 160xG for 15minutes no ficoll just 30ml's of whole blood.

    Picture 1:


    Picture 2:


    Picture 3:


    Which one can I expect and which layer do I aspirate? 

    Coen Maas · University Medical Center Utrecht

    Yes two layers it is! Make a picture, let us see what it looks like. I can do the same here if it is different.

    By the way: Ilze makes a very important remark: do not use brakes on the centrifuge.

  • Can anyone suggest an articles/books to have an idea of fifth order optical nonlinearity?

    I would like to know about various fifth order nonlinear processes, their mechanisms and the techniques for measurement.

    Safakath Karuthedath · Madrid Institute for Advanced Studies

    See Richard  L Sutherland, Handbook of nonlinear optics, chapter 6!.
    DFWM and femto Z scan can probe the fifth order effects
    Hope it helps

  • Reliability test or normality test which comes first?

    for scanning of data for further testing of hypothesis either we start with reliability analysis of scale or first we should go for normality test?

    Robert James McClelland · Liverpool John Moores University

    I assume you have scale data? I would say normality. It is a little like the chicken and egg issue, if your scale data is not normal this would probably affect reliability of data (amongst other possible issues) but not necessarily the case other way around. Normally distributed data can still yield data that falls below 

  • Can I refreeze Brefeldin A (bfa) once and use it in intracellular cytokine staining?

    I'm aware it's not recommended to thaw and refreeze bfa but I prepared larger volumes of aliquots. I would really like to be economical and use it at least once after thawing, but I was hoping if anyone who has undergone freeze-thaw once and used it in intracellular cytokine staining can share their experience. Does reusing an aliquot makes any difference in terms of interferon gamma responding T cell proportions detection by ICS?  

    Wim Jennes · Institute of Tropical Medicine

    In my experience, it is perfectly fine to freeze-thaw brefeldin A aliquots for a limited number of times. In our lab, we limit the number of freeze-thaw cycles to 3, after which any remaining volumes are discarded. By estimating the volumes required per experiment, it is possible to plan optimal aliquot volumes. Using this strategy, we have never seen any variation in ICS IFN-gamma responses. 

    Another important factor is the storage temperature. While product sheets of brefeldin A, and several other products, indicate -20°C to be suitable for storage, it is actually much better to store these reagents at -80°C. Compared to -80°C freezers, -20°C freezers freeze the reagents more slowly and also show greater temperature fluctuations during storage, together resulting in faster reagent degradation.

  • As natural polymers, are fucoidan or chitosan suitable for nanoencapsulation?

    Nanocapsules are usually made with polymers such as PCL and PLA.

    I'm new with these type of research and several works do nanoencapsulation with synthetic polymers such as PLA or PCL.

    As a natural polymer, why not use chitosan or fucoidan to nanocapsulate? Several works do the concomitant nanoencapsulation (PLA + Chitosan), but not chitosan alone. Why?

    Dipak K Majumdar · Delhi Institute of Pharmaceutical Sciences and Research

    Dear Max Saito,

    Chitosan is a cationic polymer.So dissolve it in an acidic media.Subsequently bring the pH towards alkalinity  e.g. pH 9.0 -10.Chitosan will precipitate.Thus by adjusting the pH you can make particles.

  • Oscar Beltran added an answer in Burnout:
    Relationship between Job Burnout and Job Satisfaction ?

    Any references about the relationship of job burnout and job satisfaction? How does the job burnout affect job satisfaction? There are many papers and studies concerning particular job sectors but i am looking for something more abstract

    Oscar Beltran · Centers for Disease Control and Prevention

    I believe this reference explores job satisfaction and burnout at a general level and it also explores the constructs involved in job burnout. I hope you find it useful.

    A meta-analytic examination of the correlates of the three dimensions of job burnout.

    Lee, Raymond T.; Ashforth, Blake E.
    Journal of Applied Psychology, Vol 81(2), Apr 1996, 123-133. http://dx.doi.org/10.1037/0021-9010.81.2.123

  • Alex Ignatov added an answer in Happiness:
    How much time do you spend on social sites? Is it an investment or wastage of time?

    Every one spends some time on different social networks. How much time do you spend daily (on average) and how do you utilize this time for your professional activities?

    Thank you very much for your participation.

    Happy new year 2015 for all RG fellows, their families, and friends.

    Best Wishes


    Alex Ignatov · Федеральный исследовательский Центр фундаментальных основ биотехнологии (Federal Research Center of Fundamental of Biotechnology)

    I look through questions  for 5-10 min per day, and if I can answer or I would like to find the answer for myself, I spend more time, it depends on the question. I found it very useful for my work. 

  • Keith A. Hobson added an answer in Bats:
    What is the most severe threat for bat diversity? Habitat deterioration, white-nose syndrome, wind energy or global climate change?

    Taxa respond differently to anthropogenic challenges. Therefore, it is important to identify the most severe threat for a specific taxon. Bats are special among mammals owing to their ability of powered flight, their close association with humans, and many other things. Many bats are endangered, yet we are missing a global perspective on the specific causes. I am asking for your educated guess regarding what factors are most responsible for the decline in bat diversity? I suggest four causative factors, and I leave it up to you to rank those according to decreasing importance! (Plus, you may also add a factor in case I missed one) 

    Keith A. Hobson · Environment Canada

    In North America it would be hard to argue against white-nose syndrome as being the top threat to bat biodiversity and conservation for obvious reasons. We recently ranked causes of "incidental take" to birds in Canada (including road kills) and the statistics on cat fatalities was overwhelming (see special issue of Avian Conservation and Ecology: http://www.ace-eco.org/). I wonder if these sorts of takes can also be quantified for bats? My only other thoughts are to relegate "climate change" to the last position as this has become a favorite throw-away catch all that has almost become meaningless in the conservaiton field. It is merely an excuse to do nothing while we watch more pressing issues like habitat destruction go unimpeded. Moreover, it is currently almost impossible to model the way in which climate change will play out in all but the simplest scenarios.

  • Michael Polacek added an answer in Mental Health:
    What door colors are best to use in an ED room for psychiatric/mental health?

    I have read studies that discuss mood and color in psychiatric settings, but often the study is of a person and the color which does not take into account the many other variables experienced by someone in the emergency department.  There are studies of other rooms, such as used during therapy or in the general milieu.

    I'm looking specifically for door color since our rooms are and will always be laboratory white.  I'm thinking that a great study would be to have at least two rooms with different colored doors and see which one the person (in acute psychiatric distress) chooses indicating a perception of safety.

    Michael Polacek · Salem Health

    Thanks for the thoughts,

    I appreciate the symbolism info Beatrice. 

    Kymbra, that is exactly my fear.  We bed children, people coming off meth and alcohol, folks actively psychotic as well as the very quiet young women who just tried to cut her own throat.  We need to make sure we are neutral as possible.  Unfortunately, in health care, we create systems that rule the masses and often miss out on the inconvenient fact that all humans are unique individuals.  I'll try to contact Charles Sturt University.

    We have to predict how it will look.  Mentally translating a color tile into how it will look on a door or in a room is more difficult than it sounds.  And, since this will be there for years, I would hate to choose wrong . . . 

    We have to think beyond the simple :"color" but shade and intensity as well.  We are thinking of "cool" (as Matthew says, soft) colors; in particular some mixture of green and blue perhaps what I've seen referred to as "sea foam green" which I understand to be in the "teal" family.

    I was hoping to read a study specifically on ED holding rooms.  I attached a very simply discussion on our rooms and what we would like to do in order to move away from the correctional decor and into something that communicates care.

  • Majid Mushtaque added an answer in Acute Abdomen:
    Should a trocar-induced enterotomy, recognized at re-operation, be repaired by simple closure or resection?

    Patient (54 years old) underwent laparoscopic cholecystectomy with Hasson technique and within 24 hours presented with acute abdomen.  At operation, over 1 liter of succus entericus was aspirated and an enterotomy at the anti-mesenteric border of the distal ileum, measuring about 1 cm, was discovered.  

    Majid Mushtaque · Maulana Azad Medical College

    Do a thorough lavage.. Examine the gut for possible through and through injury / injury to adjacent underlying segment of the gut. A 1 cm ileal laceration can be primarily closed laparoscpically...

  • Candace Lee asked a question in Injections:
    Fraction from preparative tlc contained alot of compounds, is it normal?

    Hi, I would like to ask that I isolated an active fraction from the preparative tlc and injected into GC/MS and resulted with more than 30 compounds in the particular fraction. Is this phenomenon normal or there's some error ? Please advise. Thanks.