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

  • Mohammed El Amine Benamar added an answer in Neutron Activation Analysis:
    Can anyone explain how determine concentration of arsenic in Biological Materials by Radiochemical Neutron Activation Analysis Methods ?

    Radiochemical Neutron Activation Analysis Methods

    Mohammed El Amine Benamar

    Dear Samir, you can see the articles below, may be, it is helpful

    + 1 more attachment

  • Jessica Tucci asked a question in Pipetting:
    What is the gell-like substance in thawed blood plasma samples and is there any way to prevent it?

    This quality doesn't seem particular to an individual species (I've seen it in both monkey and rat plasma samples).  After freezing aliquotted plasma to -70C, it's thawed on ice before pipetted out using a standard Gilson pipette.  In some samples, there is a gell like substance that can clog the pipette tip and result in inaccurate pipetting. I've had it happen to maybe 1 in 10 samples.  Am I just not thawing the plasma enough?  Is there something causing protein coagulation that I can prevent in the aliquot stage?

  • Leandro Candido asked a question in Analytical Modeling:
    Experimental vs analitycal: how to approach statistics?

    I have a set of experimental data (EXP) which I have fitted with two analytical models (AN1 & AN2).

    In order to estimate the precision and accuracy of both analytical models I can study statistics of the ratios EXP/AN1 and EXP/AN2 or AN1/EXP and AN2/EXP.

    Well, the point is that statistics of such ratios are not coincident.

    I see that many researchers adopt the first approach when I istinctively would go for the second because I can compare two different analytical models by normalizing them with respect to the same experimental variable.

    Is there anybody who can help me out with this?


  • Mohammad T. Raad added an answer in Industrial Pollution Control:
    Clays are the Naturally formed materials. can this material be used in industrial pollution control?

    Details requested are; type of clays, upgraded clays, treated clays, chemical addition in clays

    Mohammad T. Raad

    Clay supported membranes and used for removal of various pollutants like metal ion, oily wastes and other macro particles and thus may used as adsorbent.

  • Harikishan Shetty asked a question in EEGLAB:
    How to load .e file from Nicolet EEG device to matlab?

    I hope you can help me here. A have a eeg data file of a subject obtained by Nicolet which is in .e format. Am sorry i dont know the model number of the machine. I have the data viewer by which i can see the eeg waveforms. But in the viewer, there's no option to export the data. I am using Matlab version 2014b. I wish to load it in matlab for which i'll be thankful for some suggestions.

    I've tried installing eeglab, but i think there is some problem and its not supported properly in matlab 2014b because i get an error. i tried it even with the latest eeglab13_4_4b.

    Please help, thanks in advance

  • Abel Gebreegziabher Gebresilassie added an answer in VASP:
    NEB Calculation using VASP
    How can one carry out NEB (Nudged elastic band) calculations using VASP? Can anyone try to help me understand how and what is needed? I am new to such a calculations. Apart from a general objectives for why NEB calculations are necessary, I have zero experience. Any kind of help is appreciated!
    Abel Gebreegziabher Gebresilassie

    Dear Berna Akgenc ,

    It is a good news that your calculation is running. And What i meant by ordering of atoms, it simply mean atom 1 in POSCAR-00 must be the same in all the other POSCAR files. Previously  in the one you attached, that was not the case.



  • Mohammad T. Raad added an answer in Nanostructures:
    How can I increase the response and reduce the recovery time of a sensor prepared by nickel oxide nanostructures?

    I am preparing gas sensors with NiO coral like nano structures (in the form of thin films/drop casted on IDE). I am getting good sensitivity for NO gas but the response is poor (around 41%) and the recovery time is also poor. The recovery rate is very slow. Please suggest me the possible modifications that I can do to improve the response and reduce the recovery time of the sensor. Please suggest me if doping is required to reduce the bandgap (3.4 eV for NiO) or formation of some p-n junctions is necessary. Please suggest the synthesis steps for the same.

    Mohammad T. Raad

    Doping is an option. But, composites are better than doping. make a composite of NiO with organic/inorganic materials. 

  • Sebastian Nxxx asked a question in ECC:
    Looking for ECC Example Code in C -> Can you recommend some ?

    [optional : good / working / well documented ] 

    Step by Step Tutorials 

    well written guides about ECC Implementation

    Thanks in Adavance :-) 

  • A.C.D Angelo added an answer in Methanol Oxidation:
    How do I precisely qualify the synergistic effect of Pd-Pt core shell catalyst for breaking the C-H bond such as in methanol oxidation?

    I sequentially synthesize Pd nanoparticles less than 10 nm  on carbon paper and then Pt thin film  or layers on Pd particles  by electrodeposition. How to related mass activity or specific activity of Pd-Pt core shell with pure Pt performance in methanol oxidation or just take into account the potential peak shift in cyclic Voltammetry, which involve the d band shift of Pt with Pd? 

    A.C.D Angelo

    Yes, XPS is also an important tool for obtaining electronic information from the shift of binding energy of some electrons. However I meant X-Ray Absorption Specstroscopy (XAS) in the EXAFS and XANES regions. With this technique you will check out the vacancy of d-orbitals in Pt, Pd and Au surface sites. I am not sure that XRD could provide valuable information for you in this specific field.

  • k.a Galil asked a question in Suicide:
    Suicide by Dentist is it true or false ?

    Suicide by Dentist is it true or false ?

    There  is still a  controversy on the suicide of dentists ,The public still thinks dentists  have a high rate of suicide(at least that what hey think in the USA and Canada)  . i do remember years ago i read a study done in temple university(i think )   which dispelled this fact about the dentists.The question is  do dentist have a high rate of suicide?and is this question addressed in your  country

  • Touraj Farzani added an answer in TA Cloning:
    Is it true that the DNA purification kits have the potential of destroying the A tail of PCR products created by the Taq polymerase enzyme?

    I am going to do cloning by using the TA cloning kit.I am afraid that purification of the PCR products by DNA purification kit will destroy the A tail and my reaction fails.Is it possible?Thanks in advance.

    Touraj Farzani

    Dear Andrew David

    I appreciate you.

  • SK Hmn added an answer in Hemodialysis:
    What is the optimum dialysate flow rate for chronic hemodialysis patient? We generaly use 500 ml/min but is it valid for all blood flow rates?

    Raymond vanholder.

    SK Hmn

    BFR 350ml/m = DFR 700 ml/m

  • Gandhi Kishan Bipinchandra added an answer in Cloud Computing:
    Has anybody experienced working with Amazon Virtual Private Cloud (http://aws.amazon.com/vpc/)?
    Please share your feedback and experiences on working with Amazon Virtual Private Cloud.
    Gandhi Kishan Bipinchandra

    ya amazon virtual private cloud is nice tool but not the best if you want all facility then you must be use

    cloud sim

    cloud analyst

    ibm citrix

    microsoft app-v



    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: Cloud computing is an on demand technology as it offers dynamic and supple resource allocation for trustworthy and guaranteed services in pay as-you-use way to public. The specialty of this technology is that the any number of cloud services can be concurrently accessed by any number of users. In desktop-as-a-service cloud computing, user applications are executed in Virtual Desktop on remote servers. This offers great advantages in terms of usability and resource utilization; however, handling a large amount of clients in the most efficient manner poses important challenges. Especially deciding how many clients to handle on one server, and where to execute the user applications at each time is important. Assigning too many users to one server leads to customer dissatisfaction, while assigning too little leads to higher investments costs. We study different aspects to optimize the resource usage and customer satisfaction. Here in this paper a survey is carried out on the area of resource allocation strategies which tries to preserves the customer satisfaction to its maximum. The merits and demerits of each technique are also discussed.
      IEEE Transactions on Mobile Computing 12/2013; 3(12):57-61.

    + 1 more attachment

  • Hayder Obayes Hashem added an answer in Quantification:
    Can somebody provide me with a valid protocol to quantify Ethidium bromide by mean UV/HPLC ?

    Hello every one

    I need to quantify EtBr in aqueous solution with expected concentration lesser than 0.5 microgram/ml. I have a UV/HPLC in my lab but I can not find a trusted protocol to perform the EtBr quantification .

    I will be grateful for any help.

    Hayder Obayes Hashem

    thank you Osman Doluca  for your kind reply , but im looking for HPLC method for quantification Ethidium Bromide .

  • Marcos Vinicius Santana asked a question in HOMO-LUMO:
    Basis set for anions?

    I'm calculating HOMO and LUMO distribution for some molecules and getting strange results. All of them are anions at pH 7.4, so I'm using base set 6-311+G** and this is what I get for LUMO orbital. Is this normal and how can I interpret that? Or should I change my basis set?

  • Hassan Mahmoodi added an answer in Mental Fatigue:
    In Parkinson's disease, is high blood pressure a result of mental fatigue?

    Parkinson’s disease is the result of loosening of dopaminergic neurons in the central nervous system. This disease associated with both physical and mental fatigue that decreases Parkinson’s disease patients’ quality of life. Also another disorder in this disease is that blood pressure is significantly higher than the base line. Some studies have shown that mental fatigue leads to hypertension.

    Based on the above-mentioned points, is mental fatigue which has been reported in Parkinson’s disease patients may causes hypertension?

    Hassan Mahmoodi

    Dear anahita, .we have two kind hypertension, primary and second hypertension. in the primary hypertension cause  it unknown but in secondary drugs,ocp,renal disease,  and etc. you must conducted RCT or two group compare among people with Parkinson disease. Best regard

  • Brandon Lavery asked a question in Perovskite Solar Cells:
    What other metals are being tried for perovskite solar cells?

    Have researchers begun trying different metals in perovskite solar cells? I've seen tin and lead published, but what about copper, zinc, magnesium, calcium, or any other +2 metal?

  • William Long added an answer in Hip:
    A case of 17year old fracture dislocation with OA hip

    34 year male,history of closed fracture dislocation left hip 17 years back. now presented with pain left hip last 6 months ,limping since 15 years

    on examination
    left hip 30 degree FFD, further flexion upto 50
    20 degree adduction deformity
    rotations painful just jog of movt present

    measurements left side 9 cm apparent shortening
    4 cm true shortening ,which is supra trochanteric
    these are the x rays n CT scan
    2nd x ray is taken after squarring pelvis

    plz discuss regarding the management options

    William Long

    This patient should have a THA. The pelvis is caved in and the protrusio will cause the most problems because of offset in addition to shortening. I would use a cup-in-cup technique. A large trabecular metal cup deep and cement a second cup on top of the first cup. With computer navigation it is possible to place the second cup near the proper position despite the deformity. It is unlikely that one can safely restore all of the length during the first operation. I would use a modular revision stem so that when the soft tissues stretch out over the following 6month or year that one can go back and get the length safely.

  • Leonardo González Ceballos added an answer in Chemical Biology:
    Why does EDTA lower and 1,10-phenanthroline raise the reduction potential of Iron(III)-Iron(II) redox couple?

    It is observed that in presence of EDTA ligand the reduction potential of iron(III)-iron(II) redox potential gets decreased where as in presence of 1,10-phenanthroline (phen)  ligand iron(III)-iron(II) redox potential gets increased. Similarly 2,2-bipyridyl and Phen  both are bidentate Nitrogen donor ligands however phen raises iron reduction potential more than 2,2 bipyridyl how?

    Leonardo González Ceballos

    EDTA complex with Fe (III) is more stable than EDTA-Fe (II) complex (due to electrostatics issues), thus the ionic concentration of Fe (III) decrease more.  For that reason de redox equilibrium moves toward Fe(III) and the reduction potential decrease. In the case of 1,10-phenantroline, as a non charged ligand, it has a higher selectivity for Fe (II) ions rather than Fe (III). So, the ionic concentration of Fe (II) in the equilibrium is lower than the Fe (III) and it makes equilibrium moves toward products (Fe (II)) and the tendency of Fe (III) for reduction is increased, wich is equivalent to an E red increase.

  • Farooq Khan added an answer in Literary Theory:
    Can we apply Roland Barthes textual analysis from mythologies to literary texts ?

    I need references on this topic for a research article. Empirical analysis would be good.

    Farooq Khan

    Thank you Reuben, I am interested to analyze text as a social semiotic system which may embed societal values. I'm interested to understand the status of the author from the Barthesian perspective. I would be glad to get assistance from you in this regard.

  • Rene Schade added an answer in Longitudinal Studies:
    Is there anyone working with GEE models with longitudinal data (repeated data)?

    I am modelling data from a longitudinal study using GEE models. My outcome variable is  binary (yes/no) and  predictor variable (different sampling points), head size, mortality. I am  looking for literature (GEE) that will help me with the analyses. I am using the R platform. Any pointers are welcome. Kind regards.

    Rene Schade

    There is the original paper by Liang and Zeger (Biometrika 1986; also in the geepack article that Mario attached above).

    I prefer the 2003 paper by James Hanley et al though and would recommend it as a reading. Please the full text attached. 

  • David Camacho-Valadez added an answer in Child Welfare:
    Can anyone recommend research on child exploitation?

    Any research on Child Exploitation, I'm currently reading through   what I can find to  assist me in finding my own tittle for up coming research in this area.

    David Camacho-Valadez

    Hello Elaine. Here is some articles, maybe even you know it already:

    Walters, J., & Davis, P. H. (2011). Human trafficking, sex tourism, and child exploitation on the southern border. Journal of Applied Research on Children: Informing Policy for Children at Risk, 2(1), 6.

    Wolak, J., Finkelhor, D., & Mitchell, K. J. (2012). Trends in law enforcement responses to technology-facilitated child sexual exploitation crimes: The Third National Juvenile Online Victimization Study (NJOV-3). Durham, NH: Crimes against Children Research Center.

    Wortley, R., Smallbone, S., Powell, M., & Cassematis, P. (2014). Understanding and Managing the Occupational Health Impacts on Investigators of Internet Child Exploitation.

    I hope be useful in some way in your work! 

    Bests, David

    + 2 more attachments

  • Richard E. Hartman added an answer in Amyloid Plaque:
    Are fibrillar amyloid plaques beneficial in any way?

    Is there any literature suggesting that fibrillar amyloid plaques are beneficial in any way?

    Perhaps by sequestering potentially neurotoxic soluble Aβ into focal concentration?


    Richard E. Hartman

    This paper suggests that it is adaptive rather than the primary cause of neuropathology

  • Avdhoot Shrikrishna Datar asked a question in Space:
    Is CASSCF method a variational method?

    Suppose, we perform CASSCF calculations separately with two active spaces A and B, say A is bigger active space than B. Then does it mean the calculations performed with bigger active are lower bound to one with smaller active space? Since active space A has more variational flexibility compared to that of B, results obtained with A must be better than that of B. Is it correct?

  • Jabar H. Yousif asked a question in WiFi:
    Is it time to switch from WIFI with LIFI?

    Li-Fi technology is showing great promise and speeds way beyond what Wi-Fi can handle in any real-world environment.

  • Denis Korneev added an answer in Bruker:
    Could anyone help me to test my program for atomic force spectroscopy data (force distance curves) analysis?

    It is a simple Windows application with intuitive graphic interface. It is tuned for Veeco/Bruker picoforce files, but it is possible to use it for analysis of other data in TXT-table format.

    This program can plot the force curves and convert they between force-separation, force-Zscanner and force-time modes. It is possible to magnify a part of curve and measure the parameters. A user manual is in attached zip-archive (readme.pdf).

    Please use this program for analysis of your experimental force distance curves and send me reports about errors and your ideas about improvements.

    If it is possible, please send me examples of your force curve files with short description (model of AFM, version of software).

    I can send privately the source files of this program. And soon these files will be uploaded to public resource.

    Be careful when using of results. It is the first beta-version and it is possibly that it contains some errors.

    Do not judge too severely :-)

    Denis Korneev

    Dear Sebastian,

    Thank you for answer! Actually there is a problem with TXT-files - this program can read only special TXT files like "example table" file in archive. You can open this file by text editor. There is the header with parameters - spring constant, DeflSens etc. If you attach a header like this to your TXT table you can open it by ForceReader.

    What model of AFM do you use? I thought it is Veeco/Bruker. Could you send me some force curve files as example?

    Some force curve files in Veeco/Bruker format is attached. It is possible to open them by ForceReader. The next version of FR will be compatible with NT-MDT AFM format.

    Best regards, Denis

  • Thanushijah Thavajoganathan asked a question in Gears:
    Is there a Potential Replacment of Cadmium in Landing Gear?

    Anything more sustainable and less harmful