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

  • W. X. Li added an answer in TEM Image Analysis:
    What does the selective area electron diffraction with diamond shape like spots instead of circular spots?

    I have taken the SAED of Fe-filled MWCNTs and i am getting these diamond shape spots in the pattern

    W. X. Li · Stanford University

    Did you correct astigmatism in diffraction pattern?

  • Mojtaba Akhtari asked a question in Cycling:
    What chemotherapy regimen do you suggest for a young patient with hepatosplenic T-cell lymphoma as forth line before taking him to an allo transplant?

    I have a young patient with hepatosplenic T-cell lymphoma. He had 4 cycles of CHOEP, he progressed; then he had 4 cycles of SMILE with PEG-Asparaginase, and he progressed again. He received 1 cycle of CODOX-M and 1 cycle of IVAC. Unfortunately he has progressed again. His performance status is excellent, he does not have comorbidities and he has a fully matched sibling. What chemotherapy regimen do you suggest before taking him to a myeloablative allogeneic hematopoietic stem cell transplantation?

  • Dennis Slice added an answer in Allometry:
    How can I calculate different forms of allometry by software tpsreg v 1.38?

    regression of shape (weight matrix) on centroid size was been significant for my data. so it means size variations affect on shape. now I want to know how size affect on shape. which allometry form has my data? please let me now if another software is better for this analysis.....

    Dennis Slice · Florida State University

    The superimposition removes isometric size (as measured by centroid size). That is, overall magnification or reduction of the entire specimen by multiplication of all coordinates by some factor. When the tpsReg produces statistically meaningful results of regression of shape onto size that means there is allometric shape variation. That allometric variation is what is shown in the visualization tool with tpsReg.

  • Pascal Scalart added an answer in Power Line Communication:
    Why some equalizers working efficiently for Rayleigh channel does not work for power line communication channel (PLC)?

    I applied unique word based Frequency domain equalization with noise prediction for Rayleigh channel. It was working fine but when I tried to change my channel from Rayleigh with PLC, my BER is not getting low. I want to know what could be the possible reason of this when all parameters are same. Thanks.

    Pascal Scalart · University of Rennes

    Dear Khan,

    I looked to the paper on Unique Word Equalization and I also read the answer of AR Ready. I think that the problem relies on the multipath charecteristics of the channel.

    1- First case: Rayleigh fading channel

    When you said that it was working before, it was for a Rayleigh channel that was simulated by appliying a single complex coefficient h to the transmitted signal s(t) in order to get the received signal

    r(t) = h s(t) + n(t) with h being a complex coefficient whose amplitude follows a Rayleigh law.

    What is important in this case, it is that you do not have intersymbol interference (ISI) in this situation. The receiver has to estimate the value of the single-tap equalizer d = inv(h) = 1/h. If this operation is done in the frequency domain, then the equalizer is flat over the whoole band, i.e. its Discrete Fourier transform is equal to D(k) = 1/h for each frequency bin k =0,1,...,NFFFT-1.

    2- Second case:  Multipath PLC channel

    When simulating a PLC channel with the Zimmermann model, the main difference with the first case is that now we have ISI that is introduced by such a channel. So, as written in the paper , we have:

    r(t) = sum( h(i) x s(t-ti) ) + n(t) or, equivalently in the sample domain, r = H s+ n with H being a circulant matrix describing the channel. In this case, the equalier matrix H (or its equivalent in the frequency domain D) , should be perfectly estimated in order to get good BER curves.

    With the PLC channel, you said that you don't have good results. This could be a problem in the estimation of the transfert function of the channel D . This transfert function is of prime importance because it is needed for (i) the cancellation of the interference, (b) the computation of the frequency domain FF equalizer G, and (c) the computation of the taps od the FB equalizer.

    To verify that your problem is due to the intersymbol interference, you could exchange the PLC channel by a simpler one C(z) = 1 + a z^(-1) with parameter a in ]-1,+1[. You should see that (i) when a ---> 0 then the receiver is working, and (ii) when abs(a)---> 1 then the equalizer problems appears.

    Could you do this ?


  • Samuel Dobák added an answer in Polymer Electrolytes:
    What does an extended semicircle in Argand plot represent?

    I have attached the file containing the Argand plot for the polymer electrolytes. The measurements were taken in the frequency range 20 Hz to 5 MHz.

    Samuel Dobák · Pavol Jozef Šafárik University in Košice

    I don't know, because my field of research is magnetism. There are several phenomenologically similar effects, but the physical background is of course different.

  • Pablo Riba-Hernandez asked a question in Rainforest:
    Does anyone has experience on Bushnell trophy cam perfomance in rainforest conditions?

    Hi, I'm planning on monitoring terrestrial/arboreal mammals communities in a human landscape?. Bushnell trophy cams seem to be a good option, but I worry about their performance and durability under rainforest conditions?, or even variation among models? Gracias.. 

  • Darin Bellisario added an answer in Nanowires:
    When forming Ti oxide with an oxygen plasma, is the surface hydroxyl-terminated?

    When forming Ti oxide with an oxygen plasma, is the surface hydroxyl-terminated?

    RF oxygen plasma, Ti nanowires already have a native oxide from air before going into the chamber.

    Thanks for any insight!

    Darin Bellisario · Massachusetts Institute of Technology

    Excellent responses, thank you all. Particularly insightful Maria - thank you. I thought of XPS, but I'm hesitant to believe results given that contamination from ambient air, unless I do any TPD, could give me the same peaks. It sounds however like there should be plenty of hydrogen around on the surface once it sees and sits in air.

  • Prescott Deininger added an answer in dsDNA:
    What is the best melt-off solution for disruption of dsDNA hybrids?

    I have a DNA oligo immobilized on magnetic beads to which I hybridize another complementary oligo. After different enzymatic treatments and washes I want to release the oligo again. What's the best way to melt off the complementary oligo without heating the beads?




    Prescott Deininger · Tulane University

    I would clarify that normal salts will actually stabilize the duplex as you increase them because you are damping the repulsion of the phosphate bonds.  The duplex would probably come apart in pure water, but because of residual salts in the beads, it may be hard to get the salt diluted out with a small volume to make a concentrated eluate.  Urea is pretty good and formamide is probably somewhat better.  A lot depends on what you want to do with the oligonucleotide when you are done.  

  • Zoran Lj Petrović added an answer in Archaeology:
    What are the mean problems in cleaning the archeological objects and their advanced techniques?

    I want to study the using the microwave and plasma technique in cleaning some of the archeological objects, is it good research point, what is your advice?

    Zoran Lj Petrović · Institute of Physics Belgrade

    using plasma for archeological finds and their protection is an excellent topic with a lot of potential in many different areas.

  • Djahoudi Abdelghani added an answer in Actinomycetes:
    Please suggest me a lactose containing suitable medium for the growth of actinomycetes?

    I need to know about mediums which support the growth of beta galactosidase producing actinomycetes?

    Djahoudi Abdelghani · Badji Mokhtar - Annaba University

     Please prepare in 

    one 1000ml  of water 20gr agar agar + 10ml ecremed milk 2℅mineral salts  when it is coulled in Petri' s dish put on surface  dish of cellulosique on witch we must practice your  ensemencent

    Good luck

  • Santiago Velasquez added an answer in Teaching and Learning:
    Any suggestions of a theoretical framework that can be use to evaluate student centric active learning methodology in higher education?

    Education in many parts of the world has been slowly shifting from surface learning, teacher centered, rote learning methods to student centered active learning methods and the constructivist methodologies of teaching and learning. I am in the process of finding a good theoretical framework to use for my research study on this topic. I will be conducting a qualitative analysis. 

    Santiago Velasquez · University of Tolima

    I am a convinced constructivist teacher and my preference in theeoretical framework is Jerome Bruner first and Vygotsky second. What means I am more a social constructivist. 

  • Camille Dickson-Deane added an answer in Focus Group Discussions:
    What is your favorite technique for designing discussion prompts that promote peer participation in asynchronous discussions?

    What is your favorite technique for designing discussion prompts that promote peer participation in asynchronous discussions? I'm thinking specifically about the design of prompts, rather than the facilitation of subsequent conversations. Thanks for sharing! ~Barb

    Camille Dickson-Deane · Montgomery County Community College

    I specifically state how many responses are expected.  I say that because of the nature of the online environment - responding to a peer requires the inclusion of a reflective process followed by the activity of processing and writing the response.  Its not as immediate as having a face to face conversation, even though it simulates one. 

    I can say though that if cohorts are continuously expected to respond to such design  prompts, they become used to responding in that manner and then automatically perform or complete the work required.  Sometimes you may even get more than the required posts. 

    You should know that receiving more posts than required can hinder the expected exchange if and only if the original question does not incorporate an authentic activity.  Questions that incorporate authentic questions then produce meaningful discussions that can go on and on for the entire course.

  • Noga Collins-Kreiner added an answer in Science 2.0 and Open Access:
    How is ResearchGate dealing with copyright issues when posting our papers?
    I am wondering if there are any copyright issues when we post our published papers on ResearchGate? Is there any rule we should follow or we can simply upload the papers and hope that we do not really break the publisher's copyrights. I will be more than happy to know more about this.
    Noga Collins-Kreiner · University of Haifa

    Thanks so much for all the information!

  • Razia Shaukat asked a question in Mediation:
    How to treat multiple mediators in SEM?

    if we propose in a theoretical model that a particular relationship can have multiple mediators, do we have to gauge the effect of a mediator separately in the relationship of predictor and criterion variable in structural equation modeling or we can enter all the mediators in the model between predictor and criterion, will it be ok ???

  • Gourav Bhattacharya added an answer in Ferrocyanides:
    Why does the boron nitride film disappear in the presence of water?

    I have hexagonal boron nitride film (grown by CVD). While measuring the contact angle and doing the cyclic voltammetry with aqueous solution of KCl and potassium Ferrocyanide and ferricyanide I found that the film was vanished,

    What are the possible reasons?

    Gourav Bhattacharya · Shiv Nadar University

    Thanks for the suggestion .. But the surprising thing is it is not hydrophilic in nature.. I have measured the contact angle it was greater than 105 degree.

  • Peter Sobolewski added an answer in ImageJ:
    Spreading direction and velocity of a calcium signal?

    Hello everyone,

    I am working with pericyte-like cells whic have long processes. I imagine Ca2+ in these cells using Oregon green and LSM800 laser scanning confocal micsroscopy. I add an agonist and make a movie of fluorescence over time. So far I only know how to see mean fluorescence over time in a ROI, but I need to find a way to see the fluorescence as function of radial distance and time and the speed of the fluorescence spreading. I am sure there is some software which can do it, even ImageJ maybe, but I am not aware what I should look for,

    Thank you in advance, Olga

    Peter Sobolewski · West Pomeranian University of Technology, Szczecin

    In ImageJ, if you have 2d images in a stack as a function of time, then you can do a reslice to get at the information you are interested in.

    Use the Line tool (though if you click you can switch it to freehand or segmented, which should work as well) and draw a line over the area you want to examine, for example a radial direction from the nucleus to the perimeter of the cell.

    Next, under the menu Image, select Stack and Reslice. The default settings, 1 pixel spacing and 1 slice, are fine. Confirm the dialog.

    You will get a new image that is 2D. On one axis, the vertical one, y, you will have your stack, so time. On the other, x will be the pixels along the line you drew, so distance. Thus a given horizontal line gives you the values of all of the pixels along the line at a moment in time. So you can see how far the signal has propagated, for example. A given vertical line, on the other hand, gives you the intensity of a given pixel, or location, as a function of time.

  • Qusay A. Al-Kaseasbeh asked a question in OCP:
    What kind of comparisons we could have based on OCP values?

    if I have OCP values before and after Rp/Ec trend for two type of steel, could I use these values to make comparison which one will corrode firstly (more positive is noble and more negative is more active? or what kind of comparison we can have?

  • Ni Ge added an answer in Riemannian Geometry:
    Why didn't QM and gravitation merge yet?

    I've read in a very interesting paper of Prof. Norbert Straumann

    "Einstein’s impact on the physics of the twentieth century"



    In the work of Yang and Mills (1954) GR played no role. In an interview

    in 1991 Yang recalled:

    “It happened that one semester [around 1970] I was teaching GR, and I

    noticed that the formula in gauge theory for the field strength and the formula

    in Riemannian geometry for the Riemann tensor are not just similar

    – they are, in fact, the same if one makes the right identification of symbols!

    It is hard to describe the thrill I felt at understanding this point.”

    (Zhang, 1993, p. 17)


    According to this affirmation the structure of the Macro and MIcro are similar and both follow Geometrodynamics. Why didn't they merge in a unique equation then?

    They definitely individuated a background which allows everything to happen (the ACTION)Higgs field, space-time, but according to the results they didn't manage to describe it well enough yet...  it might be due also to the fact that both of them describe time reversible laws, GRT is a classical deterministic theory... Where is the Arrow of time???

    Ni Ge

    Instead of postulating a same action/motion is measured with same speed for both observators like it is in SR (actually impossible). We should admit that, with time dilation, two observers will measure different speeds for a same action/motion.

  • Simon Cleveland added an answer in Mental Processes:
    Have you any suggestions of I.C.T. usage, tools, and experiments, to monitor, access and intervene in order to raise meta-cognition abilities?

    Meta-cognition is the ability of self awareness of your own mental processes.

    Maslow's existential theory, Young's  theory of Self, Neo-Platonic theories, ICTs, Neural Networks etc

    Simon Cleveland · Brandeis University

    Dear Athanasios,

    Take a read at the following sources for additional ideas:





    Good luck,

    Simon Cleveland

  • Michael jeremy Shapiro added an answer in PVDF Membrane:
    How can i detect the proteins on PVDF membrane after the IP isolation?

    I did IP (Immunoprecipitation) and all steps of western blotting. After the result i try to use Ponceau red to detect proteins but evertime when use it for IPed proteins on membrane it didn't work. And yes, ponceau is fresh and also i tried it for another membrane which contains total protein. So i have 2 questions: Why it's not working? And how can i detect the proteins? 

    Michael jeremy Shapiro · Mayo Clinic - Rochester

    Sorry if I misunderstand, but by all steps of western blotting, do you mean you go through blotting with primary and secondary antibody, adding developing reagent, and exposing to film?  I'm not sure if you can do Ponceau at that point because the membrane would be saturated with the blocking reagent.  If you Ponceau stain before blocking and don't see any bands, then Coomasie staining the gel is an excellent control (you should definitely see bands for the antibody used for IP on either the gel or the membrane).

  • Roman V. Gulyaev added an answer in XPS:
    Can anyone help me to deconvolute Fe 2P 3/2 and 2P 1/2 XPS spectra ??

    I have a sample containing Iron carbide,Iron Nitride and Iron oxides.The XPS of Fe region gives two bands for  Fe 2P 3/2 and 2P 1/2 and a satellite peak in between.I need to deconvolute them using XPSPEAK41.Can anyone suggest references or techniques to deconvolute the peaks.

    Roman V. Gulyaev · Boreskov Institute of Catalysis

    1. Satellite peak not "between", it "after" both 2P3/2 and "after" 2P1/2 components. Second satellite, "after" 2P1/2 peak, most probably was lost due to short spectral region of signal collection. 

    2. lasurface.com, srdata.nist.gov  - this is XPS databases which comprises binding energies of many compounds of almost all elements photoelectron lines, including Fe2P. 

    3. Remember, that XPS is a surface sensitive method; about few tenth of atomic layers. Thus, you probably will see the FeOx instead of iron carbide, or nitride (or in addition to it). It means that special sample preparation route should be applied prior to acquire the "correct" XPS spectra of iron carbide and nitride samples. 

    4. If you have already collected spectral data, you should remeber about: a) spectral resolution and  b) core levels lineshape. In the case of Fe2p line, the b) factor is most complicating, because of the Fe2P both lines is asymmetric and has a satellites, wherein the shape of the satellites strongly depends on a substance (nitride, carbide, oxide, etc). Thus, you have a rather complicate spectroscopic problem, which requires a carefully solution. 

    Good luck

  • Amir Jalilifard added an answer in Fourier Transform:
    How to convert EEG raw data to frequency in order to obtain alpha and beta waves?


    I am working with EEG signals using NeuroSky headset. I can get and plot EEG raw data but I need to convert these data to frequency and get alpha waves.

    So I have some questions :

    1. What are the metrics of EEG raw data? Are they in time-domain or frequency-domain?
    2. When we want to do a Fourier Transform to get frequency domain, we need to give an specific function (e.g sin(x)) to calculate frequency. But when we are getting EEG data, we don't have any specific function. What we have is just some online data. How can I obtain online frequency domain using the EEG raw data?
    3. Is there any other way to get alpha and beta frequencies using Raw EEG data?


    Amir Jalilifard · Universidade Federal de São Carlos

    And as I already mentioned another great book for those ones who are looking for more mathematical descriptions is :

    EEG Signal Processing
    Saeid Sanei, J. A. Chambers
    ISBN: 978-0-470-02581-9
    312 pages
    September 2007

  • James Varghese added an answer in Digital Elevation Models:
    How can i create a Digital Elevation Model from satellite Images?

    i want to create a DEM from satellite images or aerial photos. How can i accomplish that??

    James Varghese · Universiteit Twente

    Hi Tenzing,

    If you have stereo pair of satellite images or aerial photographs, you can use a standard GIS software to generate a DEM based on the principles of Photogrammetry. There are open source as well as commercially available softwares which can do the job. ERDAS Imagine, ENVI, ArcGIS, PCI Geomatica, NASA's Ames Stereo Pipeline etc. are some of the names in the business. The internet has made our lives much easier nowadays. It might be a good idea to google for 'dem generation with stereo' and you will get thousands of results.

    Hope this gives you some hint. 

  • Carlos Álvarez added an answer in Enzymatic Hydrolysis:
    How I can make fractionation of lysozyme after its hydrolysis and measure the activity of these fractions?

    how i can make fractionation of lysozyme after its enzymatic hydrolysis and how determine its activity?

    Carlos Álvarez · TEAGASC - The Agriculture and Food Development Authority

    Solid phase extraction

  • Santiago Velasquez added an answer in India:
    What might be the implications of a single child preference of a developing economy like India?

    Suppose a developing economy like India develops a strong preference for a single child norm and follows the same preference over a long run. What would be the economic consequences for India and the world?

    Santiago Velasquez · University of Tolima

    Based upon what Sisodia, Max Neef and Pikkety claim I would say a single child preference would be very beneficial not only for the families, the society, the local and the global economy but also for the child him/herself. However, I do not know how utopic that could be in such a world where the interests of the powerful people who rule this world are too different from the ones who are trying to make this world a better place for everyone.

  • Jessica K. Bacon added an answer in Partnership Practice:
    What research exists on family-professional partnership practices that promote inclusion of students with intellectual disabilities?

    I am reporting research-based family-professional partnership practices that promote inclusion for students with intellectual disabilities in general education settings. Any suggestions for studies are welcome! Thank you!  

    Jessica K. Bacon · Montclair State University


    Check out my study, good luck!

  • Daniel Gebremedhin added an answer in Mathematical Series:
    Are there any approximation methods better than Taylor approximation for exponential functions with complex number in the exponent?

    say we have e^(jx), where j=sqrt(-1) and x can be any real variable. We know that even 2nd order Taylor approximation is not good enough to approximate e^(jx) with arbitrary realization of x. Are there any better approximation methods? Some say Polytopic representation might help, but I am not sure how it can.   Thank you.

    Daniel Gebremedhin · Florida A&M University

    You may also consider this.

  • Simona Stefanovici asked a question in Organic Chemistry:
    Is there a chance to get free access to an article from Journal of Organic Chemistry USSR (english translation), 1972, volume 8, p. 2478-2480?

    I work in the field of nitrone and I want to see the compound characterization from that article.

  • Simon Cleveland added an answer in Leadership:
    How can I measure leadership style?

    what instruments and measures exist to measure the leadership style ? And what would you recommend ?

    Simon Cleveland · Brandeis University

    Dear Jorge,

    You may want to look into the The Multifactor Leadership Questionnaire (MLQ):


    Also, take a read at the following sources for additional ideas:





    Good luck,

    Simon Cleveland

  • David Jensen added an answer in FTIR Analysis:
    Can anyone please help in analysing the FTIR data attached below?

    I've tried to crosslink Polyvinyl Alcohol using different concentrations of glyoxal solution.(4ml,7ml and 14 ml). But in the FTIR data, reduction of OH group and increase in C-O group are not following any trend with the increasing concentration of glyoxal. Can you please help me out in analyzing the data?? should I normalize any of the peaks? if so, which peak is to be normalized?? The data and the cross linking reaction is attached below.

    David Jensen · Diamond Analytics

    I would assume normalizing using the native PVA would be the best method to determine whether the modification is occuring. I would set the methylene stretch in native PVA at 100% (the methylene stretch should remain constant regardless of how you preform your particular modification).  Any modification of the free alcohols will result in the OH band being reduced comparative to the methylene stretch.