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

  • What is the practical solutions for improving the ranking of universities in the Webometrics ranking?

    What is the practical solutions for improving the ranking of universities in the Webometrics ranking?

    adding metadata , weblog, Links, Web Hosting, groups on Yahoo and Google, Build Institute page on Facebook, Twitter, SlideShare, researchgate, LinkedIn, Flicker, YouTube, iTunes, Open Course Ware, Wikipedia,

    Carlos Eduardo Maldonado · Universidad del Rosario

    Dear Mostafa, you named them all (or almost). The key point then is a strategic plan for "invading" and "attacking" each of this media. A combined strategy does result in a better standing at the rankings. Believe me: my university does this, actually.

  • Biswajit Mishra added an answer in Acetaminophen:
    My question, why the absorbance at 2 g/l of CM-n-TiO2 was greater than absorbance of active solution ?

    Can any one help me to explain the reasons for following point:

    I am studying photocatalytic degradation of acetaminophen in polluted water using TiO2 nanoparticles...when I test the effect of catalyst dosage of CM-n-TiO2 (0.5, 1, 1.5, 2 g L-1) on photocatalytic degradation of 3 ppm of acetaminophen under illumination of UV light. The results which has been obtained;

    * Active of solution  was measured by determining the Absorbance of solution , as following:
       Concentration       Activation
           3                           0.191
     ** Time (min)of  soln under UV

    light in incubator 
                                                                 Absorbance of soln with concentration gl-1
    Min                                                                         0.5            1       1.5       2
    Zero of irradiation of UV (10 min)                          0.192   0.194  0.196  0.250
    My question, why the absorbance  at 2 g/l of CM-n-TiO2 was greater than absorbance of active solution ?

                              Thank you ...

    Biswajit Mishra · Institute of Minerals and Materials Technology

    If I understand correctly you are basically asking that the absorbance of 3 ppm acetaminophen solution increases after adding photocatalyst before starting UV-light illumination. Then this would be due to the scattering from the fine particles of the photocatalyst present in the 3 ppm acetaminophen solution.

  • Radhwan Alnaimi asked a question in X-Ray Sources:
    How to count X-ray Source intensity?

    I am using a photo diode with known quantum efficiency to measure the intensity of my x-ray source. The diode's signal is measured on a scope with known impedance in volts.

    Can anyone help with, how to calculate the counts per second for the emitted x-ray photons.

    Many thanks,


  • David L Morgan added an answer in Grounded Theory:
    Does Grounded Theroy always have to develop a 'new' theory?

    I have been exploring grounded theory and have read somewhere that GT does not have to develop a 'new theory' but can build on existing theories. My reading suggests that there are only 'so many' theories that can be developed.  Advice please.

    David L Morgan · Portland State University

    The whole issue of how GT should use the prior literature has been quite controversial. In "Discovery of GT," Glaser and Strauss made some strong arguments in favor of ignoring the literature, so that it would not prejudice what you observe and how you interpret it.

    More recently, people have noted the impossibility of turning yourself into a "blank slate" once you have in fact gone to some effort to master the literature in your field. One alternative that is gaining in popularity is to use what Charmaz in the second edition of Constructing Grounded Theory calls "sensitizing concepts" to do what Thornberg, in a useful review, calls "informed GT." This approach essentially allows you to use broad conceptual frameworks, while avoiding the kind of "empirically oriented" theory that would generate direct implications about what you should do in the field.

    Robert Thornberg , Informed grounded theory, 2012, Scandinavian Journal of Educational Research, (56), 3, 243-259.

    With regard to whether or not you need to go the full distance and generate theory, I know of almost no article-length pieces that accomplish that goal. Charmaz certainly argues that any study which claims to be GT should indeed pursue theory, but in practice most articles stop short of that. So, I would take a look at the kinds of sources where you want to publish and see how they handle GT articles. In other words, match your own procedures to how your field actually operates, rather than to how methodologists claim it "should" operate.

  • How are antibodies linked to gold nanoparticles?

    Antibodies are crucial to target cancer cells, how they are attached on gold nanoparticles??

    Suhasini Joshi · University of Nebraska at Omaha

    Well, as far as I know

    1,4-dithiothreitol, 2-mercaptoethanol or 2-mercaptoethylamine mediated chemical reduction of antibodies will generate antibodies fragment. These fragments can be assemble themselves on gold surface due to the exposed thiol group (of cysteine residue) in PBS or HEPES.

    You can also read the paper shown in the link I have given below. They have mentioned other coupling methods in this paper as well.


  • I need to discuss the plot fit resulted from Matlab, which reference can I depend on to clarify the idea of this plot?

    Which reference can I depend on to clarify the idea of this plot?

    Alaa El Din Mahmoud · Alexandria University

    Dear Dr. Wilhelm, 

    What do you mean? This plot is not giving any indication about anything

  • Gloria Garcia added an answer in Plant Extracts:
    What are simple assays done for toxicological studies of a compound on zebrafish embryos?

    I'm testing a compound (plant extract) on zebrafish embryos. Please suggest a few simple yet effective assays to test toxicity at cellular level. 

    Gloria Garcia · Oregon State University

    One of the easiest things to look for are developmental defects, such as cranial facial malformations, pericardial edema (swelling of the heart), and yolk sac edema (swelling of the yolk sac). You can also look at pigmentation and kinks in the body axis. Additionally, conducting a dose response will let you see how much of the chemical causes an effect, such as the defects I listed above or mortality. 

  • Mohammad Nikkhou added an answer in High Voltage:
    What is the function of high-voltage substations in the network?

    What is the function of high-voltage substations in the network?

    Mohammad Nikkhou · Khorasan Institute of Higher Education


    A substation is a part of an electrical generation, transmission, and distribution system. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions. Between the generating station and consumer, electric power may flow through several substations at different voltage levels.

    Substations may be owned and operated by an electrical utility, or may be owned by a large industrial or commercial customer. Generally substations are unattended, relying on SCADA for remote supervision and control.

    A substation may include transformers to change voltage levels between high transmission voltages and lower distribution voltages, or at the interconnection of two different transmission voltages. The word substation comes from the days before the distribution system became a grid. As central generation stations became larger, smaller generating plants were converted to distribution stations, receiving their energy supply from a larger plant instead of using their own generators. The first substations were connected to only one power station, where the generators were housed, and were subsidiaries of that power station.

  • Mohammad Nikkhou added an answer in References:
    Power substations Postal refers to what?

    Power substations Postal refers to what?

    Mohammad Nikkhou · Khorasan Institute of Higher Education


    please see this site


    good luck

  • Michael Patriksson added an answer in Publishing:
    Can any one suggest me any SCI journal that has a rapid review process and may notify the paper acceptance/modification in minimum time?

    publishing paper in SCI journal

    Michael Patriksson · Chalmers University of Technology

    I think it would make it easier for us if you could narrow the search a bit. What field of research are you interested in publishing in, for example?

    And having seen questions of a similar variation before, I always ask WHY it is important that the paper is refereed very quickly. You need to be aware that many of the journals that promise very quick refereeing are not serious journals, but money-making machines that will ask you to pay a lot of money for virtually no real service at all. In fact, plenty of journals that offer quick refereeing for a fee will publish most anything, as long as you pay. I for one would never want to publish with such an unserious and unconscientious publisher.

  • Jacques Gleyse added an answer in Gender Identity:
    Can neuroscience explain gender identity?

    I’m planning to investigate the influence of neuroscience in gender identity development. I read various researches about it.
    I would like some advice about articles or new researches to deepen this field.

    Filippo Petruccelli

    Jacques Gleyse · Université Montpellier 2 Sciences et Techniques

    It's my pleasure.

  • Faiq Isho asked a question in Biomarkers:
    Can we statisitcaly find 100 % sensitivity and 100 % specificity for a biomarker ?Is that possible? And what we call that?

    We have patients with RA and controls. We have used a new biomarker. can we statisitcaly find 100 % sensitivity and 100 % specificity for a biomarker ? Is that possible? And what we call that?

  • Vladimir Ilinkin added an answer in Soil Carbon:
    How can I estimate total carbonate in soil?

    I am working on rhizospheric soil of carbonate depositing plant.

    Vladimir Ilinkin · University of Forestry

    Hi Vivek,

    Have a look in the pages 71 - 74 of Manual "Sampling and Analysis of Soil" Part X (|ICP - Forest, http://www.icp-forests.org/pdf/FINAL_soil.pdf), (attached).
    This is easy method, but you must have a Calcimeter (Scheibler unit), the principle is to destroy CaCO3 with HCl (4M) in excess and to measure the volume of CO2 produced, as Dr. Damien Ertlen said.

  • Luis Daniel Olivares asked a question in Humus:
    What do you think about the soil-chromatography technique? Advantages or disadvantages?

    I recently have seen the existence of this technique to assess the type of humus, the minerals, bacteria activity and a couple of fertility parameters. I don't know if it works or this advantages/disadvantages in front of "the conventional techniques" (in time, money, power of interpretation, bias, materials, etc.).

    I attach an image about it in the link below.

  • Van Ha Nguyen added an answer in Home Automation:
    Are Relays reliable for long time use?

    I am developing a Home automation project in which i'm using relays to control appliances. I need to control devices of rating 220v ad upto 6amp.

    So, my question is can i use relays to control these appliances as a long term solution?

    Also, if i keep a relay ON to control (say) a fan for example, for more than a few hours on a daily basis. will a relay cause any problems? If yes then What are other sofisticated solutions to that?

    [update]: relay i'm using a mechanical one and is rated 220v 7amp.

    Van Ha Nguyen · Inje University

    Of course, you can you relays. It is common.

    However, the electronic switches are more reliable for a long term operation.

  • Best treatment for Child with osteogenesis imperfecta and severe osteoporosis?

    A 13 year old child girl with osteogenesis imperfecta and severe osteoporosis and multiple compressed dorsolumbar vertebral fracture. Hx of  recurrent fractures on simple trauma. What is the best treatment for this severe osteoporosis in this child?

    Faiq Isho · University of Baghdad

    Thanks a lot Wolfgang for your answer.Best regards

  • Petter Vikman added an answer in Bioanalyzer:
    What RIN value is good for illumina RNA-seq for plant samples?

    What RIN (RNA Integration Number) value is good for Illumina RNA-seq for plant samples? I am doing strand-specific polyA-based mRNA-seq and the RIN values of my mutants are above 8 while RIN values for all three of my wild type samples are from 7.3 to 7.9 (please see the attached file). While it is generally recommended to have a RIN of above 8, I am wondering if my readings are fine to proceed. The sequencing facility used ‘Eukaryotic RNA analysis’ setting for this. I talked to Agilent people last time I ran my samples, and they recommend using ‘plant specific RNA analysis’. This could be because for plant material good RIN numbers can be lower and tissue-specific, which could be attributed to chloroplast content. I am attaching the file here for bioanalyzer readings, any suggestions, if I can proceed with these readings for RNA-seq? The goal of my project is to see differential gene expression between the two samples based on stranded library. The sequencing facility do not believe this is degradation, but possibly a normal part of the profile for plants, especially because the peaks are sharp rather than broad. Please advise, thanks! 

    Petter Vikman · Lund University

    We dont work plants so please take note of that all my knowledge comes from eucaryotic and bacterias. My experience is that RIN isn't the only important factor. A high RIN value helps but it's not the only deciding factor. If you have a realatively high RIN value and large amounts of RNA that tends to work better then higher RIN and lower amounts. Fat tissue works poorly while muscle and liver are excellent tissues to work with.

    So from your data I'd say that if you have the recommended amounts then it will most likely work. We've used samples with RIN around 5 and they have worked without problems.

  • David L Morgan added an answer in Thematic Analysis:
    Only one coder for a reliable thematic analysis?

    I am conducting a thematic analysis aiming at describing characteristics but not developing a grounded theory. I am the only coder. I was wondering if that would affect the reliability of my results. Is three any reference for this? Thanks!

    David L Morgan · Portland State University

    The whole question of reliability in qualitative analysis is rather controversial. In particular, the main way of demonstrating reliability is to have two separate coders work identically and independently on the same data. That makes sense if you are doing a content analysis where you are relying on "manifest" (rather than latent) content. In that case, there are clear rules for how to use a codebook, and the question is whether the two coders are each able to use that codebook in the same way.

    Alternatively, the more interpretive you get, the less sense it wakes to calculate inter-coder reliability. Thematic analysis analysis is quite a general approach (at least as described by Braun & Clarke), so it could involve either more manifest or more latent content. So a lot depends on the way that your are apply thematic analysis.

    That said, many qualitative research would object in principle to even using the term reliability, given its quantitative roots. Instead, they would use the concept of "credibility" and the various procedures for ensuring credibility that were developed by Lincoln & Guba (1985), Naturalistic Inquiry.

  • Amir Abbas Talebi asked a question in Coding:
    The network voltage level code is?

    The network voltage level code is?

  • How can I add Boolean Expression in momentum ADS 2011 parameter optimization?

    In 2009 and earlier versions of ADS I can simply add parameter value to be a Boolean and import it from momentum to schematic for optimization but when I write the boolean expression in ADS 2011, it gives an error:3, saying "Error preparing the simulator for expression evaluation. There could be a problem in the netlist."

  • Suhasini Joshi added an answer in BRAF:
    What does it mean when KRAS and BRAF mutations increase sensitivity of tumor cells to MEK inhibitors"?

    Does sensitivity mean it increases the likelihood that KRAS and BRAF will respond to MEK being inhibited?

    I am reading this paper "KRAS mutational subtype and copy number predict in vitro response of human pancreatic cancer cell lines to MEK inhibition" I am trying to understand it a bit better as I am new to this field. Thanks!

    Suhasini Joshi · University of Nebraska at Omaha

    Considering the importance of both Kras and BRAF in multiple cancers, including pancreatic cancer, there are many MEK inhibitors in the clinical trials. Growth factors binding to their respective receptors leads to the initiation of signaling pathways. Kras and braf are among those molecules. Kras activation followed by RAF activation causes the phosphorylation and activation of mitogen-activated protein kinase (MAPK) extracellular signal regulated kinases 1 and 2 (MEK1 and MEK2). They in turn phosphorylate and activate ERK1 and ERK2 ensued by their nuclear translocation and activation of the trancription of multiple oncogenic genes. As KRAS and BRAF, they both converge to MEK, it is believed that MEK inhibition can leads to the cancer cell apoptosis and growth arrest. Though it is not true as studies have shown that KRAS mutation (which means constitutively activated KRAS) and BRAF mutations can also activate multiple other proliferative signaling pathways independent of MEK.

    Thanks much

  • Amir Abbas Talebi asked a question in High Pressure:
    The device's low pressure and high pressure systems?

    The device's low pressure and high pressure systems?

  • Kristýna Pulišová asked a question in Parenting:
    Do you think that "parenting" and "parenting styles" are topics which belong to field of pedagogy?

    Hi, I think that "parenting style" is both pedagogical and psychological topic. But I'm searching for some arguments that it isn't just psychological problem and maybe you can help me.

  • Amir Abbas Talebi asked a question in Frequency:
    Range (Range) What is the frequency variations of normal post?

    Range (Range) What is the frequency variations of normal post?

  • Ahmed Ezzat asked a question in Tramadol:
    Please, i would like to ask if there is a technique for counting the sperm number in rat semen relative to the epididemal tissue?

    studying the morphometric norms and anomalies of sperm cells in response to Tramadol administration

    please, i would like to ask if there is a technique for counting the sperm number in rat semen relative to the epididemal tissue

  • Amir Abbas Talebi asked a question in Network:
    The frequency changes as a result of what occurs in the network?

    The frequency changes as a result of what occurs in the network?

  • Andleeb Majidah asked a question in Elliptic Curves:
    How to find the reduced-tauadic form of a given scalar ,k ?

    Actually ,this is a  topic of koblitz curve cryptography where koblitz curve is special form of elliptic curve .

    I want of find  Q=kp ,where k is a scalar and I want the reduced tau-adic form of k.

    so please help me out to find it!!!

  • Michael Lashkevich asked a question in D:
    How to obtain the Bethe function of the supersymmetric Yang--Mills theory?

    I have started to study the AdS/CFT correspondence by reading Minahan's introductory review (arXiv:1012.3983). The first equation of that review is the expression for the leading contribution to the $\beta$-function:


    \beta(g)=-{g^3\over16\pi^2}\left({11\over3}N-{1\over6}\sum_iC_i-{1\over3}\sum_j\tilde C_j\right),


    where $C_i$ are quadratic Casimirs due to bosons and $\tidle C_j$ are those due to fermions. The author cites Gross and Wilczek (1973) as a source of the formula. But there it looks a bit differently:


    \beta(g)=-{g^3\over16\pi^2}\left({11\over3}N-{4\over3}\sum T_j\right),


    where $T_j={d(R_j)\over d(G)}\tilde C_j$, $d(R)$ and $d(G)$ are dimensions of the representation and of the group.

    Forget about the boson contribution (Gross and Wilczek were not interested in it). But the fermion contribution contains there the factor $-4/3\times{d(R_j)\over d(G)}$ instead of $-1/3$ in Minahan's article. The factor 2 is related to the fact that Gross and Wilczek considered Dirac fermions, while Minahan considers the Weyl fermion. Ok. But we are left with the extra $2{d(R_j)\over d(G)}$ factor, which I am unable to cancel.

    Could anybody explain me this factor? May it be related somehow to supersymmetry?

  • Maria Sartzetaki added an answer in Museology:
    How do museums work with visitor studies in reference to older adults programs?

    I'm researching in museology, visitor studies that work with older adults or with museum programs for these visitors.

    Maria Sartzetaki · Hellenic Open University

    I've read an interesting article. Take a look at the following link


  • Ian Proffitt added an answer in Communication:
    Is it possible not to communicate?

    Some thinkers discovered that *it is not possible not to communicate*. But this is a matter of *definition*, not of discovery. If you call "communication" everything that one says and does, or does not say or do (being silent and still, included), then it is really not possible not to communicate. In that case, whatever a person does or does not do she communicates, by definition. But such position is a matter of choice and definition, not of a discovery. The fatal problem with this definition is that when *everything* is X, then X loses a specific meaning and becomes nothing. If everything is communication, then to communicate means nothing, or it simply means to exist.

    Ian Proffitt · Private