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

  • Ludovic Mathieu added an answer in Nuclear Science:
    Does the emitted beta energy spectrum in nuclear reaction 51V(n, beta)52Cr influenced by the neutron energy spectrum?

    Self powered neutron detector with Vanadium-51 used to measure thermal neutron flux in our TRIGA MARK II reactor. Another question is, how to determine the conversion factor of current produced by emitted beta in 51V(n, beta)52Cr reaction to neutron flux unit [neutron/cm-2.s-1]?

    Ludovic Mathieu

    I agree with previous statement, but I want to be more cautious.

    Your neutron-induced reaction form 52V in its excited state. It first have to decay to its ground state via isomeric transition, and then decay to 52Cr by beta decay. If there is a "long-lived" isomer in the 52V level schema, it can decay to 52Cr feeding different level than in the "standard" 52V decay.

    When looking to the 52V level scheme, it seems that there is not a lot of these long-lived isomers. But on the other hand, there is not a lot of information about fast-neutron induced formation of 52V.

    So my conclusion would be : in your simulation and assumptions it is normal to consider your spectrum to be independent of the indicent neutron energy. But if you observe something very strange in your experimental data, keep in my that this dependancy may exist.

  • Thomas Mayerhöfer added an answer in Free Software:
    Suggest free simulation software to simulate optical transmittance of thin film samples?

    I would like to simulate bi-layer thin film transmittance. Any free software?

    Thomas Mayerhöfer

    I suggest RefFIT: http://optics.unige.ch/alexey/reffit.html. The author is also on ResearchGate:

  • Alexander Sergeevich Grebenshchikov asked a question in Markets:
    What is the best EBSD system available on market right now?

    What is the best EBSD system available on market right now? In terms of post processing software capabilities, stability, performance, user interface etc.

  • Peter M. Jansson added an answer in Anxiety Disorders:
    Is there any evidence supporting relationship between depressive symptoms and house moving? Could the size difference between houses be a risk factor?

    Moving is often described as one of the major risk factors related to affective and anxiety disorders. In my clinical practice I have found it sometimes as well, but, could be the eventual loss of space the clue of this kind of stress? Is there any statistically significant difference between depressions after moving to a bigger or smaller house?

    Peter M. Jansson

    Hi, see for instance,  Mats Ekstrom;  Residential relocation, urban renewal and the well-being of elderly people: towards a realist approach.

  • Krishna Del Toso asked a question in Sanskrit:
    Help me please with a Cārvāka verse in Jinabhadra and Hemacandrasūri?

    Hello everybody! At present I'm studying the occurrences of the following Cārvāka stanza in the Jain literature:

    etāvān eva puruṣo yāvān indriyagocaraḥ | bhadre vṛkapadaṃ hy etad yad vadanti bahuśrūtāḥ ||

    Another reading of the same is:

    etāvān eva loko’yaṃ yāvān indriyagocaraḥ | bhadre vṛkapadaṃ paśya yad vadanty abahuśrūtāḥ ||

    In particular, I'm interested in checking directly the Sanskrit versions preserved in the following two works:

    - Hemacandrasūri's Ṭīkā commentary on Jinabhadra's Gaṇadharavāda 1.5 (ed. Vijaya, Ratnaprabha and Dhirubhai P. Thakar. 1950. Kṣamāśramaṇa Jinabhadra Gaṇi's Gaṇadharavāda: Along with Maladhārin Hemacandra Sūri’s Commentary. Ahmedabad: Sri Jaina Siddhanta Society, p. 10).

    - Jinabhadra’s Svopajñavṛtti auto-commentary on his Viśeṣāvaśyakabhāṣya (ed. Malvania, Dalsukh (ed. by). 1966-1968. Acārya [sic] Jinabhadra’s Viśeṣāvaśyakabhāṣya with Auto-Commentary. Ahmedabad: Bharatiya Sanskrit Vidyamandira, Vol. 2, pp. 344 and 439).

    Since I don't have at my disposal these editions, I was wondering if there is someone among you kind enough to provide me with a scan of the aforementioned pages or also with a transcription (with diacritical marks) of the three occurrences of the verse under concern.

    Thank you in advance and have a lovely day!


  • Manuela Tolve added an answer in UV-Visible Spectroscopy:
    Why are the absorbance values using a traditional spectrophotometer and the nanodrop different?
    We tried to compare the absorbance values of several copper sulfate standard solutions using Evolution 220 spectrophotometer (the traditional one), and the Nanodrop, but we we're surprised to find very different values, differing by more than twice. The Nanodrop typically gave higher values for the absorbance. Can anyone explain why this is the case? I thought that Absorbance values should be the same for different spectrophotometers? Because if not, how do you for example rationalize calculating the protein concentration based on absorbance values at 280 nm?
    Manuela Tolve

    Dear All,
    I have the same problem with DNA concentrations.
    For the same sample of DNA, the quantification with nanodrop 2000 and with spectrophotometer perkin elmer UV/VIS I read very different absorbance.
    After calculation of DNA concentration, the DNA read with spectrophotometer has a 151.5 ng/uL concentration, the same DNA read with nanodrop has a concentration of 8 ng/uL.
    The nanodrop uses pathlength of 0.5 mm instead 1 cm, but in manual i have read that the software normalizes the concentration (in the final report) with 1 cm pathlength.
    I can't explain these differences of concentrations.
    If any of you can explain me if i have to correct the concentration of DNA that gave me nanodrop i would be very happy.

    thank you

  • Anoop Kumar Srivastava added an answer in Sprinkler Irrigation:
    Is there a paper about comparison of furrow, drip and sprinkler irrigation?

    I need papers or your answers about the comparison between these methods of irrigation particularly about soil moisture and nutrient movement, as I need that at my Ph.D. studies 

    Anoop Kumar Srivastava

    Noha , please find enclosed a PDF comparing drip irrigation with conventional basin irrigation in citrus . Hope , you find it useful.

  • Mario Zunino added an answer in Social Networks:
    Do scientists tend to gain preferably informations which confirm their opinion and fade out contradictory statements?

    I heard (Süddeutsche Zeitung, February 6/7th 2016), that people like to sit in a "reverberation chamber", they are consuming only informations which confirm their opinions, because it feels good to be liked or confirmed.

    The social networks tend to strenghten this behavior, especially with the help of new filter systems, which gain new connections by evaluating the personal data of the user.

    Is this contradictory to objective thinking and having an open mind?

    What about the filtering systems of RG?

    Mario Zunino

    I agree with what Robert Keith writes. However I consider desirable that the English speaking scientists take into account also  the works written in other languages, regardless of bibliometric assessment of journal in which they are published. Although I feel inelegant quoting myself, I’d remind that when Gonzalo Halffter and I  faced the issue of Onthophagus (Coleoptera: Scarabaeinae) associated with caves or underground nests of vertebrates, at a global scale,  we considered ethically correct to make an extensive literature search. It turned out a corpus of 116 papers published from 1894 to 2006, in English, German, Spanish, French, Italian, Russian, Romanian, Ukrainian, Polish, Czech, that we fully consulted. This approach derives not only from scientific ethical principles, but also by other kinds of considerations. All of us agree - I hope - in considering biodiversity as a value. I personally believe that the cultural and linguistic diversity is a value to be preserved and defended against the global homologation.
    Reference: Zunino, M. & G. Halffter, 2007. The association of Onthophagus Latreille, 1802 beetles (Coleoptera: Scarabaeinae) with vertebrate burrows and caves. ELYTRON, 21: 17 – 55 (available on ResearchGate)

  • Aparajita Lahree added an answer in DMSO:
    Why do I have a band with the wrong product size after PCR?

    I am trying to amplify a vector by pcr. I linearised the vector with EcoRI and BamHI to ensure no re-ligation. I then purified the linearised vector and used that in my pcr reaction. I am expecting a product around 6.1kb, but I repeatedly get a product around 0.5kb. My primers are good, they are at unique sites and have Tm's of 68 degrees (I am using a 2-step reaction). I use 3% DMSO in the reaction, 10 ng of template vector and 0.5uM F.C for my primers. My primers have 25 bp overhangs homologous to the insert I plan to assemble into the vector. Those overhangs are not homologous to any region in my vector. So far I have tried varying the annealing temperature in both 2-step and 3-step pcr reactions by the touchdown pcr method and just having a single annealing temperature and I have tried varying DMSO %. Can anyone give me advice on what might be happening, and how I might be able to amplify the full 6.1kb. Thanks.

    Aparajita Lahree

    Hi Jacob,

    In my experience, the times I obtained a ghost band of much lower molecular weight that desired, the target band was always missing. In my case however, we figured out the cause to be some contaminating DNA and therefore repeated the entire protocol with all equipment washed in SDS and distilled water. It does sound trivial yet, did cause quite a hassle. 

  • Pradeep Paswan added an answer in HFSS:
    Is it possible to use PIN Diode as switch in RFID Tag Application?

    i am trying to tune rfid tag antenna (in HFSS simulator) at 865 MHz and 925 MHz using PIN diode as switch. when switch ON(R=3ohms,c=0.1pf) ,antenna is tuning to 920Mhz .when switch OFF(r=3.2Kohms,c=9pf) , antenna is tuning to 925Mhz. how to set PIN diode?

    Pradeep Paswan

    you can model the pin diode with resistant and capacitance.

  • Andrey Sinjushin added an answer in Molecular Markers:
    A very basic question about molecular marker: how to develop a marker for a trait?

    Suppose, I want to find a marker for drought tolerance in maize which nobody has identified yet. So, how can I develop that marker so that in future it can be used by others to screen populations for drought tolerance?

    Andrey Sinjushin

    There is an old strategy. If you have the desired trait segregating in more or less monogenic way, you may collect DNA samples from F2 hybrids, then make pools of DNA from 10 plants of one phenotype and from 10 of another and then make a PCR with any randomly amplified fragments (RAPD, ISSR, IRAP, REMAP etc.). You use 10-plants sample as a single DNA sample. If you find any fragments which are present in one spectre and absent from another, this may mean that this marker is tightly linked with desired gene. Then you need to excise it from gel and sequence, this can allow you to design this fragment-specific primers.

  • Abhishek Raj added an answer in Cryptococcus:
    Isolation of cryptococcus from refrigerated CSF?

    How can I go about isolating cryptococcus from refrigerated CSF samples?

    Abhishek Raj

    See below link for said query, might be useful for you.



    Abhishek Raj

  • Zaid Khalaf Khidhir added an answer in Meat Quality:
    What should be the sample size, in meat quality studies, to detecting a statistically significant difference between groups?
    Zaid Khalaf Khidhir

    Sample size
    Depends on the:
    expected variations in properties within a population
    the seriousness of the outcome if a bad sample is not detected
    the cost of analysis
    the type of analytical technique used

  • Ishmael Lente asked a question in Ecosystem Services:
    Please, how can I calculate or measure the vulnerability of smallholder farmers to loss of ecosystem services quantitatively?

    I am researching the vulnerabilities  and adaptation strategies of smallholder farmers to loss of ecosystem services in the context of a changing climate in semi-arid areas.

    "Research on Climate variability and change and ecosystem services"

  • Sahar Solhjoo added an answer in Galanthus:
    Can anyone provide a method for micropropagating Galanthus nivalis in vitro?

    Does anyone have a method (protocol) for in vitro propagation of Galantus nivalis or at least for Amaryllidaceae family?

    Sahar Solhjoo

    reading this article may help you:


    authors: A. Tilly-Mandy, E. Jambor-Benczur, J. Szabo

  • Nibin Tom asked a question in Talus:
    What are the procedures for Talus fine sample collection?

    Does anybody know about Talus sample collection methodologies. Please share any relevant publications also.

  • Ulrike Fischer added an answer in Cardiomyocytes:
    Which company's FBS would you suggest for the proper cardiac differentiation of P19Cl6 cells?

    Hello all,

    I have been trying to differentiate P19Cl6 cells into cardiomyocytes. However the efficiency is quite low. I know that serum plays quite important role for the process. Do you have any suggestions about that? So far, I tried almost every FBS version of Gibco and none of them worked better for me. 

    Thank you very much for your help in advance

    Ulrike Fischer


    maybe this paper will help you

    FBS (HyClone)

    Nakamura T, Sano M, Songyang Z, Schneider MD. A Wnt- and beta
    -catenin-dependent pathway for mammalian cardiac myogenesis. Proc Natl Acad Sci U
    S A. 2003 May 13;100(10):5834-9.



  • Zhili Wang added an answer in Phase Contrast:
    Phase Contrast in X-ray Imaging?

    How can phase information be modulated to intensity ? Is it implemented in the clinical world? I am new to this field, so just want to ask few questions. 

    Zhili Wang

    Several reviews on phase contrast X-ray imaging have been published in Physics in Medicine and Biology, and Journal of Physics D.

  • Roslan Awang added an answer in Human Resource Management:
    What are the hot issues in Human Resource Management and Technical Vocational Education and Training (TVET) ?

    I'm keen to explore the recently highlighted issues in 'HRM and TVET' to explore new areas of research.

    Roslan Awang

    The TVET curricuculum offered by stake holders, does it up to date and related to the market demand.?

  • Aparajita Lahree added an answer in ImageJ:
    How can I quantify cell colonies using Imagej?

    Hi all. I would like to quantify my clonogenic assays using ImageJ. Anyone able to guide me on how I could go about doing this? TIA

    Aparajita Lahree

    Hi Alexis. The system is pretty binary so yes you can try to use the cell counter plugin as Tobias suggested, but in case you have a lot of data points per field, then a macro is better and faster. Here is a document to aid you with the automated counting on imageJ https://www.unige.ch/medecine/bioimaging/files/3714/1208/5964/CellCounting.pdf

    Good Luck

  • Dr Vinay K. Srivastava asked a question in India:
    Can we measure Disinvestment Policy of government of India on the basis on Target and Achievement?

    The GOI adopted the policy of disinvestment of Public Enterprises in 1991 and the proceeds of disinvestment is using to bridge the gap of fiscal deficit.

  • Pradeep Paswan added an answer in HFSS:
    When we check the Far fields report in design of antenna using HFSS,we can see some colours, can U tell in brief about those?

    After the design of antenna,

    In the images some colours like red , yellow , blue etc.... are there please tell about those

    + 1 more attachment

    Pradeep Paswan

    color represent strength of filed. green one represent strong filed ,yellow is moderate and red one is poor filed.

  • Lakhdhar Yosra added an answer in Network Security:
    How to measure Network Immunity?

     Networks are always under threats so how to improve the network immunity?

    Lakhdhar Yosra

    I'm looking to mathematically modelize w cyber defense system, but I don't know how to do that. Can you help me 

  • Fabrizio Proietti added an answer in Glutathione Peroxidase:
    Simple method for glutathione peroxiadase measurement ?

    Can anybody suggest methods to measure glutathione peroxidase ?

    Fabrizio Proietti

    In my opinion this is one of the best. Is robust and reproducible. https://www.caymanchem.com/product/703102

  • Afrooz Rashnonejad asked a question in Umbilical Cord:
    Which Blocking Buffer should be used for Mesenchymal stem cell (MSC) flow cytometry?

    We want to do flow on MSC isolated form Umbilical Cord Blood for surface markers. for reducing background staining I think we must use blocking buffer. What is the ptotocol and components of blocking buffer for MSC flow?


  • Nibin Tom added an answer in Biotite:
    Can anyone suggest a reliable chemographic diagram for representing meta-aluminous granite?

    The granite is meta-aluminous calc-alkaline with ilmenite, epidote, sphene, biotite, hornblende,plagioclase, microcline (megacrsyts) and quartz (Silica saturated) assemblages. The granite have mingled with basic magma to variable degree. Your suggestions will be valuable and helpful. 

    Nibin Tom

    Thanks Emmanuel

  • Ian J Slipper added an answer in XRD Analysis:
    Which is the suitable software for XRD analyzing for new compound?

    Hello all

    I prepared new transition metal complexes and i need for free XRD software for pc to analyze the new compounds (unknown) to give many parameters such as the structures, unit cell, lattice parameters, miller constants and other. 

    Thank you all

    Ian J Slipper

    Software for these purposes are not a magical [data in - results out] black box. How much experience do you have in crystallography and XRD in general? You will need to understand the theory that underlies this, each program will have its own strengths and limitations and a knowledge of theory will help you to avoid incorrect answers - it is much easier to obtain incorrect answers than it is to find a true solution. I recommend that you find a training course for structure refinement before you start to gather the data.  You can start by reading the pages prepared by Jeremy Cockcroft in the link.

  • Zaid Khalaf Khidhir added an answer in Shrimp:
    What is the proximate composition of protein and lipid in chicken meat (particularly breast meat) and greasyback shrimp (Metapenaeus ensis)?

    I need this information because i have used them as feeds for my experiment

    Zaid Khalaf Khidhir

    chemical composition is  about 16.44 - 23.31% protein, 0.37 - 7.20% fat, 0.19 - 6.52% ash, and 72.8 - 80.82% moisture content in Chicken meat

  • Rita Payan Carreira added an answer in Sertoli Cells:
    Are these Sertoli cells or interstitial cells?

    To determine the cellular localization of protein, immuno- histochemical analysis was carried out from fish testis.

    Are the positive signal(yellow) Sertoli cells or interstitial cells?or others?

    Rita Payan Carreira

    Which yellow cells are you referring to? the one inside tubules? or those in the interstitium?