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

  • Firdos Jahan asked a question in Chitosan:
    Ionically crosslinked chitosan/pva blend film is not swellining in distiiled water at room temp.suggest me why it happend?

    as i crosslinked the blend film in ionic salt solution.but when this ionically crosslinked film is dipped in distilled water it is dissolving in it completely not swelling..according to literature it should swell in distlled water as it behaves physical hydrogel..then why it is melting in water?i also have ried hcl acid of ph 2 for sweeling of film then also it is failed.why?

  • Federico Brivio added an answer in Conductivity:
    Want to know with insulators that have an energy gap above 4ev, whether they show positive photo conductivity or negative photo conductivity?

     Explanation of positive and negative photo conductivity in insulators and semi conductors

    Federico Brivio

    My guess here, is that you are considering doped materials. But in general, insulator do not allow conduction and exciting electrons above band gap can result in different, complex physics.
    Which system are you considering? What type of conduction?

  • Zeynep Sezgin added an answer in RNA Yield:
    Did anyone used PureLink® RNA Mini Kit (Ambion) for total RNA extraction from whole blood?

    I need to extract total RNA from whole blood samples in order to perform RT-PCR. I tried PureLink® RNA Mini Kit, but RNA yield was low and quality was bad. Blood samples were fresh and stored in EDTA tubes. I tried to extend lysis time but the results were same. Does anyone have suggestions about this problem?

    Zeynep Sezgin

    Dear Mohammad Pourhassan-Moghaddam,

    Thank you for your answer. I extracted RNA from whole blood and I already used column-based method. I think problem is the initial blood sample volume (200 ul). But kit works with up to 200 ul pf fresh or frozen blood. I don't know how I yield high RNA with this kit?

  • Campbell Reece asked a question in Control:
    Seeding cells in triplicates, in 6-well plate?


    I want to seed my cells in triplicates in six well plate (due to density issue)

    There are six groups for my experiment and I need 18 wells in total.

    How should I seed them? I've heard that there are plate variations and you cannot put data in a single graph if the cells are seeded in different plates...

    Should I seed..for example

    Control 1 Vehicle 1  Treatment 1

    Control 2 Vehicle 2 Treatment 2

    Control 3 Vehicle 3 Treatment 3

     in separate plates?

    Or Control 1, 2, 3, Vehicle 1, 2, 3 in one plate and

    treated groups 1, 2, 3 in a separate plate?

    Thank you very much

  • Jessee Moirangthem asked a question in Movement Therapy:
    Can anyone suggest a good approach for movement therapy for PTSD?

    I am working with a mixed group of adults with post-traumatic-stress-disorder. Since it is my first time with such group I would like to know any clinical or therapy experts what is the most appropriate way to initiate therapy with such groups and if working on the periphery is a better option rather than going to the depth of the trauma.

  • Jukka Westermarck added an answer in Kinase:
    How much concordance is there between Immunohistochemistry (IHC) & FISH testing for detecting mutation-dependent overexpression of target kinase ?

    There is a good /validated antibody for doing the IHC.  

    Jukka Westermarck

    I don´t know but rather the combination is used to confirm the status. E.g. in Her2 diagnostics, +-++ IHC combined with FISH status confirms patient stratification to Perception theray

  • Marcel M. Lambrechts added an answer in Fitness:
    What is your definition of 'fitness'?

    It's all in the question


    Marcel M. Lambrechts

    Thanks Arie!

  • Debabrata Sengupta added an answer in Reaction Mechanisms:
    What is the rate equation for galactose oxidase?

    Please let me know the rate equation for galactose oxidase. If two molecules are attached in TS. Is it possible that rate is dependent on both the molecules?

    Debabrata Sengupta

    Thank you Dr. Rafik and Dr. Adam. Rate equation must follows Michaelis equation. However, In one of our model system it follows normal 2nd order kinetics as stated by Dr. Rafik. Is there any discrepancy?

  • Boyko B Georgiev added an answer in Parasites:
    Can anyone identify the "organism" attached to this water boatman Trichocorixa verticalis?

    soft body; 2 mm approximately; with some filaments; it penetrate the body of the corixid; I wonder if it could be some kind of parasite...

    + 2 more attachments

    Boyko B Georgiev


    I would check for fungi of the group of Saprolegnia.



  • David Ulaeto added an answer in Protein Extraction:
    I have a gel when I extracted my proteins with RIPA? is not the sufficient volume to an efficient extraction or there's another explanation?

    I Extracted cell proteins with RIPA buffer and after centrifugation, I have a gel instead of a liquid supernatant. Anyone could explain me the reason? 


    David Ulaeto

    If your sample was from cells or tissue, then you may have a lot of DNA in the sample, which will make it gloopy.  You can get rid of the gloopiness after RIPA treatment by treating with a commercial exonuclease, or by passing the sample a few times through a syringe and needle, which will shear the DNA into small fragments.

    A further possibility is that the sample is just very concentrated. The only real way to deal with that is probably to dilute it a little. but I would try digesting or shearing DNA first.

    Hope this helps,


  • Jatish kumar Bag added an answer in Soil Analysis:
    Hi all, How can we quantify unknown compound composition from Match3?

    Any one who is dealing with soil samples (XRD data analysis by match)

    can you help me on this?

    Jatish kumar Bag

     Thank you Sir Joseph George Ray

  • Julie Bendix added an answer in Cluster:
    Interpretation of negative loadings in discriminant analysis?

    Hi all

    We are using different independent variables to understand the intention to use and usage of mobile payment solutions. Dependent variable is intention to use.

    We have three discriminant functions loading according to the following:

    1) Result demonstrability (0,62), Compatibility (0,55), Perceived usefulness (0,54), Perceived ease of use (0,48), Risk (-0,44), intention to use (0,34)

    2) Trust (-0,60), Image (0,54), Enjoyment (0,43)

    3) Subjective norm (0,83)

    Our four clusters have the following group centroids:

    Cluster 1: F1= -0,97, F2= -0,28, F3= 0,38

    Cluster 2: F1= -3,6, F2= 0,76, F3= -0,23

    Cluster 3: F1= 1,98, F2= 0, 15, F3= -0,21

    Cluster 4: F1= -1,70, F2= -1,10, F3= -0,26

    We are a bit unsure of how to interpret the above. Especially with regard to the risk and trust constructs which both have negative loadings on functions.

    Can anyone help up interpret this?

    Your input is highly appreciated.

    All the best,


    Julie Bendix
    That indeed make sense!

    Yes, we did try to do run the analysis with three groups, but basically only the first function has an influence and it further contains all the variables, except Subjective norm. This is why we wanted to try with the four clusters, but then we got a little confused about the interpretation of the negative loadings and especially how to interpret function 2? :)
  • Martyn Queen asked a question in NHS:
    Does anyone know of a validated survey that can be used to determine the impact of an oncology provider intervention in the British NHS?

    I am developing a brief intervention for use with oncology providers in the NHS. Does anyone know of a validated survey that can be used at 6 month follow-up to assess the impact of the intervention.

  • Vladimir B Stankovic added an answer in CST:
    What is connection between impedance and power for discrete port in CST MW&RF?

    What is connection between impedance and power for discrete port in CST MW&RF? Which power corresponds to the value of impedance of 50ohm?

    Vladimir B Stankovic

    Thanks Hans-Walter and Marcelo!

  • Adelio A S C Machado added an answer in Environmental Impact Assessment:
    How does the challenges of 'Sustainable Development' make the goals of Environmental impact assessment more difficult to achieve?

    sustainable development and Environmental impact assessment

    give ideas and post journal articles

    Adelio A S C Machado

     'Sustainable Development' (SD) involves three dimensions (the 3P, Planet, People and Profit) and numerous 2D and 3D interactions among them, therefore optimization processes are much more complex that in 1D Environmental Sustainability. Environmental impact assessment is a tool to  support Environmental Sustainability, and therefore when applied in the more global 3D framework of SD has to pay attention to 2D more, society ( humans)   and economics, involving more targets (often conflicting targets!) and  naturally being more difficult achieve.

  • Lotfollah Alipour added an answer in Thermal Comfort:
    Has anyone ever used RayMan to calculate PET?

    My research relates to outdoor thermal comfort and I want to calculate PET & PMV to determine outdoor thermal comfort.  

    Lotfollah Alipour


    - excuse me. the possibility of importing a set of data as input data is there. you can Import input files for free calculation of Tmrt, PMV and PET. for this purpose, at first, need to create of a datafile (simply txt file) and then input it. 

    - you can get more information about the PMV that used by both, in attached file and link.

    -for comare of results of both PMV, you can compare results of Rayman with values into table D.1 of ISO 7730 "EXAMPLE OUTPUT"


    + 1 more attachment

  • Rito Baring added an answer in Storytelling:
    I am currently undertaking my dissertation and was wondering if anyone has any research on the uses of storytelling in cultures and religions?

    I found information on the use of storytelling in the Australian Aboriginal and Native American Indian cultures but would like more reliable information.

    I also found information on the use of stories in the Bible but would also like more reliable information.

    Many thanks.

    Rito Baring

    This article might be relevant for you:

    Baring, R. 2013. Narratives of Healing in Suffering: religious education in media. Religious Education 108(3), 263-279.

  • Sujoy Sarkar added an answer in Zero:
    Why use reducing agents in nanoparticles synthesis?

    In nanoparticles synthesis, reducing agents change metal into its zero oxidation state,which form cluster with other atoms and then coated with capping agent, why necessary to change metal into zero oxidation states, which force responsible to form clusters?

    Sujoy Sarkar

    You have mentioned in your text, that reducing agent reduces metal from ionic to zero state. without this, metal would be in ionic state as dissolved ion in the solution. So reducing agent reduce ion to metal zero state, which further stabilized by the capping agent. In the absence of the capping agent, metal, after reduction will agglomerate and precipitate out.

  • Odette Sandrine Bakam Nguenouho asked a question in Filter Design:
    How to Design and Implementation Interdigital Capacitor in a Band-pass Filter?


    I have being trying to replace the lumped element capacitors i have in the band-pass filter design with the Interdigital Capacitor, but i'm facing problems. In fact the interdigital capacitor was design using ADS, then putted together  the rest of the circuit, that's where the problem comes. Because the filter response has change dramatically please advise on what to do?

  • Mohamed Mohsen Gammoudi added an answer in Text Classification:
    What is the more appropriate information retrieval model for short texts ?

    information retrieval data mining  santimant analysis   data analysis

    text classification text clustering 

    Mohamed Mohsen Gammoudi

    Dear Fadoua,

    I think that the best model for short text  is the vector space model

    Read : http://www.csee.umbc.edu/~ian/irF02/lectures/07Models-VSM.pdf

    Best regards

  • Debabrata Sengupta added an answer in Fuel Cells:
    What will be the minimum criteria for using a molecule in direct alcohol fuel cell (DAFC)?

    What will be the minimum criteria (like performing some definite chemical reaction) for using a molecule in DAFCs? Please consider Grutzmacher complex.

    Debabrata Sengupta

    Thank you Sujoy for your answer. Can you please tell me whether removal of proton and electron from the system needs to be separated or not?

  • Raam Kasinathan added an answer in Chemical Processes:
    What are the different methods through which we can prepare amorphous nickel hydroxide (as an electrode for nickel cadmium battery) on a plant scale?

    Given below is one method through which we can prepare amorphous nickel hydroxide nanospheres.

    The amorphous Ni(OH)2 nanospheres were synthesized using a unique electrochemistry technique that is simple, green and low cost. Two parallel flakes from cleaned graphite were used as the cathode and anode, both with a working area of approximately 1.0 × 1.0 cm2. Both electrodes were inserted in a quartz chamber with a separation of approximately 5.0 cm. A target of 99.99% pure nickel, with a diameter of 25.0 mm, was fixed at the center of the chamber floor and immersed in high-purity de-ionized water (18.2 MΩ cm−1) without any chemical additives . The technique was performed in constant potential mode with voltage 75 V.

    Raam Kasinathan

    Now a days, foam metal electrodes and plastic bonded electrodes are also used. they have increased surface area and cyclic stability.  in the foam type, metallic foam, is impregnated with nickel hydroxide along with conductive additives. The later one uses  plastic binders.

  • Ammar A. Hajjar added an answer in Electrical Power Engineering:
    S-transform vs wavelet in detection of electric power disturbances.

    Hi, I need an opinion about, what transform can I use to detection of electric power disturbances?

    Ammar A. Hajjar

    The following paper may help you:


  • Jawahar Sharma added an answer in Trace Element Analysis:
    Can knives contaminate fruit samples in elements analysis?

    I have been recently asked to join a project dealing with measurements of nutrients and trace elements (e.g. Mn, Cd, Cr, Cu, V etc.) in fruits. This is not my greatest area of expertise, thus I am sorry if my question may look trivial. When peeling and/or cutting the fruits, would it make a difference if I would use a stainless steel knife or a glass (porcelain) knife? I have been told by some other people in my department that any contact with metal during the preparation of the samples will alter the final results. Is this true? And, if yes, which is the magnitude and for what elements? I would like also to have any reference to papers dealing with this topic.

    Jawahar Sharma

    Save your sample from all kind of contamination prior to analysis. You may cut or peel of your sample with quartz glass or teflon blades. But before peeling, dip the teflon or quartz blade dipped in deionized water for 24 hours.

  • Remi Cornwall added an answer in Cosmology:
    Is there Godel's Incompleteness Theorem in Physics like in Mathematics?

    The holy grail of Physics is the Unification Theory called by Weinberg as the "Final Theory". When finally discovered, perhaps it can:

    1. Unify all fundamental forces in nature.

    2. Explain the Hierarchy Problem

    3. Explain all Cosmological Problems 

    5. Gives us the right Quantum Interpretation

    but can such theory derive all fundamental dimensionless constants in nature out of pure number and explain the true nature of time?  

  • Pascal Paillier added an answer in Cryptography:
    Is there a way to prove a secret by third party without revealing it?
    The third party should be able to prove that secret is associated to the respective member or user or client .
    Pascal Paillier

    Hi there,

    many thanks :) my goal at the time was to create fully homomorphic encryption but I never was able to get there. Then lattices started to show the way. But I'm like you, I'm convinced that more things can come out from just playing around with cute algebraic tricks, and I havent yet given up the construction of a number-theoretic FHE scheme :)

    Cheers & have fun, Pascal.

  • Elin Jørgensen added an answer in Diabetic Foot:
    Is there anyone using honey for the dressing of wounds? why aren't the people convinced about it's efficacy in wound healing?

    in  my clinical practice i've been using honey for the treatment of venous ulcers, bed sores, burns, necrotising fascitis, burst abdomen and even in case of diabetic foot too. i heve seen wonderful results. there is scarcity of data in terms of trials and most of the surgeons don't agree to accept it but is a good debriding agent.

    Elin Jørgensen

    I think honey have many well proven qualities against infections in chronic wounds, the potential against biofilm infections (MRSA and PA) seems though to be "only" 70-90% (Alandejani et al., 2009). I think it is very important to choose a quality product, as a study has shown that many has bacterial contaminations (Carnwath et al., 2014). I am an equine clinician, and I also use medical honey on wounds with success (horses, like people, suffer from chronic wound healing)

  • Liubov Shubina added an answer in Cryopreservation:
    Has anyone used Fluoro-Jade stain in PFA perfused brains?


    I want to detect neuronal degeneration through the use of Fluoro-Jade C (Chemicon International).

    I have rat brains perfused with PFA, preserved 2 days in PBS(0.01M)-sucrose 30% for cryopreservation. Finally, the brains were cut in 20 um sections and conserved in PBS 0.01M.

    I used the protocol of the datasheet. After mounting the sections on a gelatinized slides, and leave them dry 30 min at 50ºC, I made the steps in the protocol.

    -5 min in 1%NaOH in 80% EtOH

    -2 min in 70% EtOH

    -2 min in distilled water...

    During the distilled water step, the sections started to swell, increasing their volume and making wrinkles in the tissue.

    I have try it with another sections and the result was the same.

    Anyone has some idea of what is happening?

    Than you in advance.

    Liubov Shubina

    Hello everybody! I guess I'm late with this answer... Anyway, I faced with the same problem and I solved it by adding several drops of acetic acid buffer to the all ddH2O steps. And it gave perfect results. dH2O alone may make sections come off slides easy. Probably, the problem is that water has high surface tension, which can cause folds, "bubbles" or minor wrinkles. Acetic acid buffer helps to reduce the surface tension in water.

  • Yashwant Shrirang Munde added an answer in Natural Fibers:
    How to conduct LAMINATE Analysis of SHORT Natural fiber reinforced Polymer Composites?

    Is it required to have Laminate analysis of SHORT FRC? if YES the What is the methodology?

    How will you find Orientation of fiber in the laminate and Orientation has any effect on Mechanical Properties? (Strength and modulus along Longitudinal and traverse direction)

    Yashwant Shrirang Munde

    Dear Pankaj Biswas Sir,

    In practical is it really behave as isotropic? What are the relation  values between  E1, E2, E3 for short fiber reinforced laminates.