Q&A

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

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
  • Richard Chukwuma Meribe added an answer in Abaqus:
    Can someone help me with on Abaqus CAE data and measurement units?

    I have just finished designing a model using AbaqusCAE.Please can someone provide me with advice or video link on how to read and plot the data of my completed work in Abaqus.      

      I have already seen this https://www.youtube.com/watch?v=4XqV41QS5lk (from 4:30min) but I cannot understand how he got his values for his data and graph plotting . 2)

    Also please,how can I verify the units and magnitude of forces,pressure and other parameters used in my Abaqus CAE analysis?

    Richard Chukwuma Meribe · Kumamoto University

    Thanks Guys.Your answers and contributions are doing a great deal of help.

  • Do you think whether it is proper to connect gravity exclusively with the speed of light?

    Since the beginning of the twentieth century the speed of light is thought to be fundamental to gravitation and its transmission effectiveness. Mathematical physics seeks whether this idea is sufficient for explanation of all phenomena related to mass attraction. Is a change of position needed? What is your opinion?

    Marwan M. Obeidat · Hashemite University

    I mean the space(s) out there, dear Arno!

  • Graeme Smith added an answer in Cognitive:
    What is the best approach to study the Problem of Consciousness?

    The Problem of Consciousness:

    http://www.imprint.co.uk/chalmers.html

    Cognitive approaches:

    http://www.mind.ilstu.edu/curriculum/consciousness_sci_of/cognitive_approaches_to_consc.php

    Are there any other approaches?

    Dorian, one quote does not consensus make.

  • Narasim Ramesh added an answer in TCAD:
    What do negative capacitance in AC simulation in TCAD signify ?

    While trying to do AC small signal analysis of Ultra Thin Body (~3nm) FDSOI NMOS transistor (that I have coded in TSUPREM4), the MEDICI calculates the Y-parameters and gives negative capacitance values. What does this signify about me device? Is it too small for MEDICI to calculate correct value of parasitics or does it have something to do with my device structure/meshing ? WHat can be done to avoid these negative capacitance? Thanks!   

    Narasim Ramesh · Sri Jagadguru Chandrasekaranathaswamiji Institute of Technology

    It is an interesting question from the idea of negative capacitance..I am not familiar with the tools mentioned .following is a general response open for review and consideration.

    1. Please check numerical stability and be sure of the values.

    2. It is possible to give meaning to  negative resistors .(. they are energy sources.).

      and also mutual inductance (the induced voltage changes sign depending

      on coil configuration.

    3. in the same way it can be supposed mutual capacitance could be negative.

    4 For incremental parameters (say operating around a quiescent point) the

     r l and c values would be the coefficient in a two port model so it arises

    in linearizing  a non linear phenomena around for small signal values. Describing

    functions are sometimes used in such cases. Note often limit cycles mark the stability limit in many nonlinear situations.

    5.  One possible approach to determine the veracity of your result is to start from

     known correct values and gradually reduce parameters . Possibly plots

    of such analysis may reveal the cause..

    Good luck

    Cheers

  • Christian Cantos added an answer in Competent Cells:
    Is preferable/necessary to purify my ligation mixture before the transformation step?

    Should I purify my ligation mixture before transforming the competent cells? Or would I be able to directly use the mixture, but suffer from a reduction in transformation efficiency instead?

    Christian Cantos · International Rice Research Institute

    Hi,

    You can directly add your ligation mix to your competent cells. But be sure not to put too may of the ligation reaction because the buffer in the ligation mix might inihibit transformation efficiency. So for example if you have 10uL ligation reaction you can start using half of it for transforamtion and divide the half to 3uL and 2uL for another transformation so you can have varying concentration of the ligation mix.But as for me, purification is not really necessary.

  • Tristan Croll added an answer in Docking Software:
    Is it logical to use Cu2++ ion as receptor and a protein as Ligand, assuming the protein is rigid ?

    I am using hex as docking software, which assumes the ligand to be rigid. When I am trying the reverse, my protein as the receptor and the Cu2++ the final complex does not show any interaction, which should be.

    Tristan Croll · Queensland University of Technology

    I don't think Hex (or any standard docking software) is the right choice for a problem such as this. They're primarily based upon geometric fit, which becomes pretty much irrelevant when your ligand is a single spherical ion. Affinity between copper and any site of your protein will be based upon charge, van der Waals interactions, and geometric agreement with preferred coordination arrangements. The latter in particular are not handled in any docking software I'm aware of (except FlexX, but only where the ion is a part of the docking site for your ligand) - or, for that matter, in any classical molecular dynamics forcefields. There's no simple approach, I think.

  • Tisham Mohammed asked a question in Religious Studies:
    If religious studies is included in education in a country with multiculture,mulltethnic and multiple religious background,how would you address it?

    Please the paper related to the issue, https://www.researchgate.net/publication/268576703_Influence_and_Controversy_of_Religion_in_the_Evolution_of_Canadian_Education

  • Rahul Kumar Bansal added an answer in BPH:
    What is the role of dutastaride in treatment of mild BPH?

    Mild Bph is sometimes treated by watchful waiting so, could one introduce dutastaride if the prostate volume is above 50mls?

    Rahul Kumar Bansal · McMaster University

    The treatment should be based on the symptom score and degree of bother. It may or may not require medical treatment for mild lower urinary tract symptoms. 

  • Vigneswaran Veeramuthu added an answer in Corel:
    Whats the exact corelation between the full moon day and tides and its effct on psychological behaviour of man and other animals ?

    In full moon days there is a increase in the tide in the sea and few relate this to mood up and swing and a abnormal behaviour .whats relate all together is it a myth does any scientific evidence to prove their corelation .

    Vigneswaran Veeramuthu · University of Malaya

    I don't think there is any scientific basis to that claim. The following is simple yet factually correct article in  describing the myth . http://www.scientificamerican.com/article/lunacy-and-the-full-moon/?page=2 

    The authors of the article has also given some references for additional reading at the bottom of the article.

  • Kamlesh Kumar Sahu asked a question in Human Rights:
    Is there any journal exclusively for human right and mental health?

    I mean which is dealing with this issue or any special issue in any professional journal 

  • What is the influence of grating on Raman spectra of carbon materials ?

    When looking for experimental conditions leading to the most beautiful Raman spectra of disordered carbons, I realised that the grating had a somewhat high influence on the results. Let me explain. Switching from a grating of 600 to 1200, 1800 or 2400 l/mm obviously led to a higher resolution but also to a lower signal/noise ratio. But I also observed that, doing this, the intensity ratio of the G/D bands changed, do you know why? For getting a high signal/noise ratio with an grating having a higher number of lines/mm, I used higher acquisition times until the spectra were smooth and very nice, but the relative intensities were totally different. Can it be due to local heating, because of the correspondingly high acquisition time ? What do you suggest for having reproducible spectra? I have never seen this problem reported in the literature, so I wonder if this could be due to a temperature effect, or to a calibration problem of my spectrometer.

    Satyaprakash Sahoo · University of Puerto Rico at Rio Piedras

    Afer looking at your Raman spectra I think the obtained results are not related to grating. I do not expect laser heating for a laser power of 4.5 mW. But if you can still decrease the power to 1 mW by filter it would be an ideal condition to avoid heating. From your spectra, I have another observation; there is a difference of about 200 unit in the intensity at the left hand side background of your spectra. And a similar difference in unit can be noticed in the two D peak intensities. I wonder if you can compare these two spectra after subtracting the background in such a way that both the spectra reside on the same background. You can do it quickly using origin or the software associated with your Raman instrument. Remember your D peak is on a background. I hope this will solve your problem.

  • What are the current standards for diagnosing bipolar disorder in children, and how accurate are the diagnoses?

    I am writing an argumentative essay exploring the validity and ethics of diagnosing children with bipolar disorder.

    Kamlesh Kumar Sahu · Institute of Psychiatry, Kolkata

    DSM V

  • Are genotyping of Giardia (C,D,E,F,G,) Infected human or not?

    Any Genotyping of Giardia lamblia infected human exception (A,B) 

    Harith S. Al-Warid · University of Baghdad

    Dear Dr.Muhammed
    Giardia intestinalis-Assemblage (E) was reported in human from isolates collected in Egypt the article was published in 2008. Please see the following article that illustrated the first report of Assemblage (E) in human.

    Foronda, P., Bargues, M. D., Abreu-Acosta, N., Periago, M. V., Valero, M. A., Valladares, B., & Mas-Coma, S. (2008). Identification of genotypes of Giardia intestinalis of human isolates in Egypt. Parasitology research, 103(5), 1177-1181.

    accept my best wishes.

  • What is the minimum acceptable volume fraction resulting from rietveld refinement quantitative analysis?

    As I know the XRD method cannot detect phase below 5%.

    I am using Match 2.3.3 software, and the software gave the volume fraction below 5%.

    Can that be right?
    Please guide me.

    Hossein Mohseni · Isfahan University of Technology

    I am working  on Ni-Zn ferrite auto-combustion synthesis by GNP method, some impurities peak has been observed but I couldn't recognize all of them.

    There is spinel ferrite , FeO, ZnO and something else, probably organic (because of glycine ).

    It would be very nice if you give me a reference that i can use it in my thesis.

  • What is the best software for simulation of Power electronic projects?

    Hi

    What is the best software for simulation of  Power electronic projects such as DC/DC converters with high Input-Output Voltage or Current? I think that MATLAB some times is not good for them.

    Best Regards.

    Mutharasan Anburaj · Veltech High Tech Dr.Rangarajan Dr.Sakunthala Engineering College

    Dear Friends,

    I can suggest you to try for VissiM software, which is similar to work as in Matlab. But they are the compatator for Matlab.

    Kindly check it.

  • Krishnan Umachandran added an answer in Competition:
    How dose the non competitive antagonist decrease response ?

    Non competitive antagonist dose Not compete agonist to receptor, therefore by which mechanism dose it decrease the full response?  

    Krishnan Umachandran · Professor

    Antagonist or test inhibitor can inhibit the effects of the natural ligand (hormone, neurotransmitter), agonist, partial agonist, and inverse agonists. We can think of them as inhibitors of receptor activity behaving as competitive, noncompetitive and irreversible antagonist

  • Zaidi Embong added an answer in Igor Pro:
    How to use Igor Pro software for deconvolution of Ti3p peak in XPS spectra to elucidate W4f peaks with their doublet shape?

                         Dear researchers I used XPS PEAK 4.1 software to elucidate the W4f peaks from Ti3p peak and evolved W 4f peaks but their doublet shape is not revealed. Then I came to know that Igor Pro is the best soft ware to do so. I downloaded it from "http://igor-pro.software.informer.com/download/ " but I dont know how to use it and when I had a glance at its manual I found that the instructions are too extensive to follow. Right now I have the data of the high resolution XPS peaks is in form of "*.txt", "vgd", "ASCII" files.

                   The requirements to get accurate deconvolution of those peaks are mentioned in the paper titled "Study of the Reduction Behavior of W/Ti02
    Catalysts by XPS using Curve Fitting, Deconvolution and Factor Analysis"-----"In order to achieve a successful deconvolution, each spectrum must be pretreated. Pretreatment includes background removal and spectral smoothing. The backgrounds were removed using a Shirley-type integral and spectral smoothing was carried out using a cubic All data analysis programs (GOOGLY Software) were written in house by A.P. The Jansson algorithm implements an iterative type of procedure that can be controlled interactively by a visual evaluation or by monitoring the residual variance between the original data and the reconstructed data (i.e. the convolution of the broadening function and the current deconvoluted spectrum). The most important variable in any deconvolution is the broadening function. In the present case the broadening function was chosen to be a symmetric Voigt function" with 20% Lorentzian character. The width chosen happened to be slightly narrower than those used in curve fitting (see below) the spectrum of interest. In our case the width was selected to be 1.9 eV. This allows for maximal deconvolution while not losing components because of 'over deconvoluting'.

    Now I need to follow the above instructions using Igor Pro software. Hence I request the experts of this field to guide me. Thanking you for your valuable suggestions. 

    Zaidi Embong · Universiti Tun Hussein Onn Malaysia

    One more thing, CasaXPS is also capable to convert the data from any system to Vamas format. (example: *.dset to Vamas format)....Vamas is universal format...some XPS instrument has their own data format...This CasaXPS is design especially for Kratos XPS system but in some cases, it also capable for other XPS system such as Thermo or Omicron Nanotech system...

  • Alicia Barrientos added an answer in Culture Cells:
    Issue with immunostaining of cultured cells?

    I have been doing immunostaining of cultured cells. The current issue is that I don't see any positive stain. One thing that worries me is the fixation and permeabilization step. Is it possible that the protein (both in cytoplasm and nucleus) got lost or washed away during the steps? I used ice cold acetone for 10 min RT. I have been searching the fixation and permeabilization steps online. The are pretty similar. Has anybody ever had this experience before? The same procedure works fine in tissue sample. It's tricky for cultured cells on slide. 

    Alicia Barrientos · City University of New York - Queens College

    Are you using an established lab protocol, or are you troubleshooting a protocol? If it is the former, look back to your lab notebook and try to identify where you could have erred. If you are troubleshooting (which seems to be the case), the process can be painstaking. You do not want to shock your cells and degrade your epitope. You may have to change the incubation times, or your dilutions. Tweak these factors in very systematic ways and see what works. I wish you the best of luck. I am attaching a very good IHC paper which may or may not be of use.

  • Why has tetrahedron taken as geometrical object to study Loop Quantum Gravity ?

    Is this only due to simplicity ?

  • Tengfei Ma asked a question in ATP:
    Which one is the real effector? ATP or ADP hydrolyzed from ATP?

    An allosteric enzyme is reported to be activated by ADP. Recently, I found that ATP could also activate the enzyme in a similar manner (decreasing the Km of the substrate). But ATP could slightly hydrolyze to produce ADP to some extent. How can I completely prevent the ATP hydrolyzation? or is there any method to verify that ATP is a real effector like ADP or not? 

  • Publications on Entrepreneurship ?

    What publications can be recommended on Environmental Entrepreneurship and Educational Entrepreneurship ? Who has practical experience with those fields ?

    Jamal F Hosseini · Islamic Azad University Tehran Science and Research Branch

    recommend journal of small business and entrepreneurship.

    We have done some research on entre education so you could follow up on my publication

  • Thanh Nguyen added an answer in Primer:
    What are the role of PCR in detecting unknown diseases?

    The scientists already know the DNA sequence of a HIV virus based on which they develop the primers called HIV primers. Now during the PCR they mix the DNA sample of the person with this HIV primer (along with enzyme and nucleotides), and if this sequence matches with the target (patient's) DNA there will be amplification which means that the person is infected. And if the sequence doesn't match then there will not be any amplification which means that the person is not infected. If this right what are the role of PCR in detecting unknown diseases?

    Thanh Nguyen · Delaware Technical and Community College

    It's interesting to see the idea of how you can use PCR to detect the samples infected with HIV. I really don't know the answer for this question but it made me think about the DNA testing using PCR to see if the kid belongs to the father.

  • Does anyone know of studies on the concept of Infinite from an anthropological point of view?

    Metaphysical conceptions of the Infinite in particular cultures or in a cross-cultural perspective; interdisciplinary studies on this theme, between Philosophy and Cultural Anthropology.

    Albert L Refiti · Auckland University of Technology

    Answer was to Francesco Spagna question relating to "Metaphysical conceptions of the Infinite in particular cultures or in a cross-cultural perspective; interdisciplinary studies on this theme, between Philosophy and Cultural Anthropology" sorry canʻt do math

  • Jyotsna Verma asked a question in Swarm Intelligence:
    Is there any literature on location prediction in MANET using any swarm intelligence technique ?

    Is there any possibility, we can do any research in this field ?

  • Oleg Laptenko added an answer in mRNA Decay:
    Does Actinomycin D need a vehicle group?

    I am trying to confirm the mRNA decay rate.

    and, Actinomycin D was dissoved in DMSO.

    If I treated Actinomycin D to cell, then, should I treat the DMSO to cell, too?

    to compare the changes.

    Because, Actinomycin D is generally used as a drug that is essential to confirm the mRNA decay.  So, I am wondering whether I treat DMSO to cell or not to compare Actinomycin D treated group.

    Oleg Laptenko · Columbia University

    As a rule of thumb: always use the solvent in your mock-treated samples. Therefore, if you used DMSO for ActD solubilization, use DMSO in the mock samples. If DMSO for some reason affects the results (it is not neutral, after all), try and use different organic solutions (MeOH, EtOH etc), alternatively, prepare a highly concentrated stock, therefore you will minimize potential background effect of the solvent.

    Good luck

  • Mohamad Afifi added an answer in Tidal Waves:
    Is it known for tidal waves to create a shock wave or any sound?

    A tidal wave passes two times per day around Earth. This means, the lateral speed of the wave peak is extremely high, something like 1700 km/h at equator, which is higher than speed of sound in air. 

    It is known for supersonic objects to create a shock wave and extremely loud sounds. Yet, I never heard of sounds induced by tidal waves, or of any shock waves. Are there any effects of such quick waves?

    Also, what is the resonant frequency of longest range waves in World Ocean? Are the tidal waves slower or faster than resonance?

    Mohamad Afifi · Universiti Teknologi Malaysia

    waves in water have free surface, any increase in energy i n the waves will cause the surface to rise.. in shallow water wave speed is proportional to root o water depth..waves from deeper region just pile up and increase the water surface leading to what is called a tidal bore.

    May i suggest you conduct another simple experimengt..  drop a stone in the centre of a pond and watch the waves moveaway from the centre ..the speed corresponds to the depth.

  • Abhay Kulkarni added an answer in LNA:
    How do you design a biasing circuit for an FET transistor using RF Frequency (GHz range)?

    I am designing a Low Noise Amplifier (LNA) for Ku-band(12GHz). For that I am using HJFET transistor. I am looking for the biasing circuit which can be useful to block RF signals of GHz range but allow DC signals. 

    Abhay Kulkarni · Indian Institute of Science

    As far as I understand, you can use bias tee to block ac and pass dc supply from source to transistor pin. The bias tee consists of a capacitor and an inductor. It can be used as Ell Match as well for impedance matching. 

    You can go through Microwave Circuit design book by Gonzalez which mentions Ell match. 

    By the way, are you using linear model or a non linear model for NE3511S02?

  • Xianfeng Wang added an answer in HUVEC:
    Loosing HUVECs during LPS incubation to stimulate cell activation?

    I'm currently using a 100 ng/ml LPS solution (in cell culture media) to stimulate activation in HUVEC. However after I finish the LPS incubation and wash with PBS, I visually observe apoptosis along with a major disappearance of my cells. Could it be that the LPS solution is too strong? Would it be causing cells to detach? This does not happen in all of my wells. 

    Xianfeng Wang · Wake Forest School of Medicine

    LPS concentration is fine. What about your cell density you seeded?

  • Irina Afonina added an answer in Real-Time PCR:
    How can I analyse qPCR data with different efficiencies?

    I compare control with treated sample and use single HKG

    First I was using ddCt method, but then decided to switch to more precice Pfaffl method to include my efficiencies which are not the same. However, they are also not the same within same gene in control and treated.

    GOI (control) = 0.93         GOI (treated) = 0.88

    HKG (control) = 0.97         HKG (treated) = 0.91

    Which one can I use for calculations (in REST)? I was thinking about average or smallest?

    Or maybe I should still use ddCt method as my validation works? (standard curve of ct(GOI)-ct(HKG) produces trend line with slope <0.1)

    Thank you

    Irina Afonina · Nanyang Technological University

    Thank you all for your answers.

    I believe my problem in different efficiencies between treated samples and untreated lies in RNA purity.  I always use RNA RIN values above 8, but  I don't precisely control for salt/organic contamination. I perform magnetic beads purification and take from there..

    Isabelle R Miousse , In this case using few HKG wouldn't help (I actually use 2, but in all cases in treated samples efficiency is less)

    Jochen Wilhelm,  I estimate efficiency based on standard curves (automatically in BioRad software). why can't I trust calculated values if it shows good correlation with different concentration? what method do you suggest?

    Sean Wyatt, I was thinking of standard curve analysis, but it seems that my control (untreated) is my external control. I work with bacteria, and wild type is my "untreated" and  one of the gene-deletion mutant is my "treated".  So in the case what would be my another control? 

    So I always run standard curve for HKG, GOI for both control and treated and from there take mid-point, let's say 1 ng from 100-0.001 dilutions for calculations.

    Jivko V Stoyanov,  do you mean  we substitute all 2 to corresponding efficiency?  That sounds reasonable...

  • Jiansheng Wei added an answer in Magnesium Alloys:
    How can I make ultra-fine twins in magnesium alloys by the forging method?

    I have tried so many times but couldn't succeed. For large mechanical properties, fine twins are required in magnesium alloys.

    Jiansheng Wei · Central South University

    @Hans J. Roven

    There are problems on  these tricks if you combine them to realize it. They work against each other, well, most of them.

    Most of all, you do not want precipitation occure during deformation. Hight strain rate could be easy to work, but low temperature and highly alloyed samples with twins could painfull, especially when you want much plastic deformation and low temp annealing between steps.

    Right now I am working on this, data tells that it is easy to outline the theory, but not the actural twins.

    Go for one of the factors, maybe less pain in the ass.