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

  • Said Zidan added an answer in Basin Analysis:
    Does anyone have information about drainage basin analysis of eastern desert in Egypt?

    Does anyone have information about drainage basin analysis of eastern desert in Egypt?

    Said Zidan

    Dear Abdo 

    PhD thesis of Dr Moawad Badway, Cairo University was dealing with drainage system in safaga-El Qusier area
    Kindly find the attached file 

  • Hussein Shareef added an answer in Crop Yield:
    How can we quantify the contribution of quality of irrigation water to crop yield and quality?

    Role of irrigation water in raising the quality production of crops is undisputed. But ,still irrigation water is most unjudiciously used, without any prior appraisal  of irrigation resource vailability on quantitative and qualitative terms. I have following quarries with regard to contribution of quality of irrigation water vis-a-vis crop yield and quality:

    * What is exactly meant by quality irrigation water?

    * What are upto date criteria for evaluation of irrigation water quality for agricultural and non-agricultural purposes?

    * Do we evaluate quality/suitability of irrigation water according to types of crops to be grown?\

    * Whether total dissolved solids contribute distinctly towards nutrient requirement of crop?

    * What are the  nutrients supplimented by irrigation water that aid in reducing the crop nutrient requirement?

    * Do we consider the quality of irrigation water in crop planning in a given

    agro-pedoglogical situation?

    Hussein Shareef

    Thanks to share of an important question, that the effect of water quality have to do with texture of soil in which the plant grows where consists of the soil solution which benefits the plant thus production may increase if you use good soil with low-quality water, and here I do not mean salt water because quickly affect plant even in good soils.

  • Marzieh Siamak asked a question in Questionnaire:
    Please full the questionnaire


    Dear Sir/Madam

    Attached questionnaire is provided to determine evaluating indicators of information literacy instruction models. Please help the researcher by investigate and judgment content and face validity of the indicators. Please determine the suggested indicators what extent assess information literacy models. If you think the suggested indicators should be corrected, please modified the indicators or suggestions related to the indicators mentioned in the description. I am appreciative for spending time, attention and accuracy for responding.

    Best regards

    M. Siamak

    PhD candidate, Department of Knowledge and Information Science, Hamedan brench

  • Herbert Weidner added an answer in Electromagnetic Fields:
    What is the boundary between Electromagnetic near and Far field?

    Hello everyone as you know when light scattered from any object then both kind of waves produced propagating and non propagating or evanescent waves. From the scattering spectra of the propagating waves how can we identify that this is the boundary or interface between the near and far field? How can find that interface or point or bridge between near and far field?

    Herbert Weidner

    In the far field, there is no phase shift between the electric and magnetic component of the field and both are orthogonal. That a true transversal wave. It is sufficient to measure the E-component, because E/H=Zo=377 Ohms.

    In the near field, there is no pure transversal wave and there are additional radial components. Other formulas apply: The phase shift is a function of location, and the ratio E/H is a complex number. There is no fixed border, where suddenly other formulas apply.

  • Raj Kumar asked a question in PLD:
    Which method is best method to make nano-SnO2 thin film for DSSc?

    I am having nano-SnO2 nano composite, suggest me for best method among these(Sputtering and PLD) with reason to DSSc's research. 

  • Larissa Deviani Salaki asked a question in Acoustics:
    Where is the fundamental frequency of this spectrogram?

    I'm new to acoustics and trying to describe and analyze loud calls of red langurs. Loud calls of this species has never been studied previously, so there's no reference I can look up to. I need suggestions to determine if:

    1. the loud call is tonal or non-tonal (I think they're non-tonal)?
    2. is there any predefined "names" for the shape of the spectrogram (a, b1, b2)?
    3. where (on the spectrogram) is the fundamental frequency (F0)?

    Any inputs will be very appreciated. Thank you.

  • Sun Yung added an answer in Limma:
    How can I evaluate both and up regulated genes in a microarray data?


    I'm studying about detection of differential expressed genes (DEGs) by using disease vs healthy samples microarray data. I use Limma in Bioconductor for analyze the DEGs. I realize that some of DEGs are both up and down regulated. For example, while ARAP2 gene was upregulated in 2 probe set, this gene down regulated in 3 probe set at one dataset. How is this situation occur in transcriptome level. Is this gene up or else down regulated in real? How are we explain both up and down regulated genes in same dataset?

    Sun Yung

    Any large is your n? How many biological replicates and technical replicates do you have? This is why a large dataset is important to distinguish experiment errors/variations from real biology. 

  • Lata Rana asked a question in Metal Complexes:
    I m not getting the crystals of metallic complexes

    actully I  have prepared some metallic complexes. it is dissolved only in DMSO and partially in DMF so I can not capable to grow the crystals so please give the suggestion for solving this problem .

  • Kati Taal asked a question in Antibody Detection:
    How to transfer free ubiquitin as well as poly-ubiquitinated proteins to the same membrane?


    I would like to visualize both poly-ubiquitinated protein species (from 63 kDa to 200 kDa) as well as free ubiquitin (8.5 kDa) on the same Western Blot. I’d be using a 4–15% Mini-PROTEAN® TGX™ Precast gel to separte the proteins and VU-1 (Life Sensors) antibody to detect them. Should I transfer these proteins using the same conditions or should I cut the gel into two pieces and use different transfer conditions, e.g longer and wet transfer for poly-ubiquitinated proteins and shorter semi-dry transfer for free ubiquitin?

    Many thanks in advance,


  • Marzieh Siamak added an answer in Information Literacy:
    I need evaluating indicators for information literacy models, please help me


    Dear Sir/Madam

    Attached questionnaire is provided to determine evaluating indicators of information literacy instruction models. Please help the researcher by investigate and judgment content and face validity of the indicators. Please determine the suggested indicators what extent assess information literacy models. If you think the suggested indicators should be corrected, please modified the indicators or suggestions related to the indicators mentioned in the description. I am appreciative for spending time, attention and accuracy for responding.

    Best regards

    M. Siamak

    PhD candidate, Department of Knowledge and Information Science, Hamedan brench

    Marzieh Siamak


    Please full the questionnaire


  • Rania Magadmi added an answer in Conotoxins:
    Does anyone have experience in block mouse cultured dorsal root ganglion?

    I'm running experiments and I need to silence the mouse DRG in culture. I'm thinking of either Lidocaine or Toxin cocktail (TTX with conotoxins). Does any one have experience in this and willing to share some information regrading protocol conc. duration etc.

    Rania Magadmi

     Hi Refik,

    Thank you for your replay and suggestion. what about TTX-R in DRG culture?? do you have idea to block them? and what is your opinion about using lidocaine to block DRG in culture?

  • Bharat Grover asked a question in Semiconductor:
    Why mos2 is a n type semiconductor ?

    single layer of mos2

  • Mohamed Taha added an answer in Financial Stability:
    Does anyone know of a measure that assesses attitude towards teamwork? or if they have teamwork skills?

    Hi, I am attempting to study an intervention program being set up for Syrian Refugees to aid their social and financial stability. I need certain measurements to see if the intervention was effective. I want something that measures their attitude towards teamwork, negative/positive thinking (or discouraging thoughts), and attitude towards productivity (I wanted to ask for all these but research gate limits the length of your question). I found other measurements for other constructs I'm measuring, but these are the only ones I am having trouble measuring. I have ideas for alternatives, but I would just like to see if anyone had ideas or knew of any measurement tools. Thank you so much.

    Mohamed Taha

    go to the site mindtools.com and u will find a lot of articles about how to build a team and ways of assessment their effectiveness and motivation

    if u got lost of overload of information come back to me on my mail to send them for u

    my mail is drmohamedtaha56@yahoo.com

    good luck 

  • Hubert Dabire added an answer in Pressure Transducers:
    What is the lower end limit on tubing diameter to successfully perform invasive blood pressure measurements in rats?

    Our lab group currently uses a conscious, unrestrained but tethered 275-350g male Wistar rat model of sepsis. As part of this model invasive blood pressure measurements are taken continuously. Currently this is achieved by cannulating the carotid artery with PE-50 tubing, tunnelling the tubing to the nape of the neck and exteriorising through a swivel attached tether system. A blood pressure transducer measures the blood pressure changes by tracking the fluid dynamics within the tubing.

    This surgery required to place this line (and a jugular line to administer fluids) is quite invasive and I would like to reduce the surgical severity if possible. This will likely require choosing more distal cannulation sites where blood vessel diameter is smaller and where the tubing we currently use would be too large. Smaller tubing would therefore be required however I am concerned that smaller tubing will lose patency more easily and/or simply not transmit blood pressure information well enough.

    Does anyone have any advice or experience on this - particularly what the lower limits for tubing diameter for successful blood pressure measurement would be.

    Many thanks.

    Hubert Dabire

    Some years ago, we used similar techniques for intra-arterial BP recording in conscious unrestrained and untethered rats. Details of our technique can be found in the following publications: Am J Physiol Heart Circ Physiol 275:H1290-H1297, 1998 and Am J Physiol Heart Circ Physiol 292:H2506-H2512, 2007. In particular, we constructed polyethylene catheters [a PE-10 (2 cm length, 0.28 mm ID, 0.61 mm OD; Clay Adams, Parsippany, NJ) fused to a PE-50 (15 cm length, 0.58 mm ID, 0.96 mm OD; Guerbet, Louvres, France)] filled with heparinized 0.9% NaCl (50 U/ml). The catheter was inserted into the lower abdominal aorta via the left femoral artery to record distal (peripheral) aortic BP. The catheter was tunneled subcutaneously under the skin of the back to exit between the scapulae and was plugged with a short piece of stainless steel wire. After 24 h of rest, the catheter was attached to another PE-50 (15–20 cm). At least 2 limits must be highlighted: 1) whatever the diameter of the catheter, its tends to be obstructed with coated blood even if its filled with heparinised physiological saline. 2) Catheterisation of femoral artery leads to a heavier surgery than catheterizing carotid artery, as one have to tunnel the catheter through all the length of the back of the rat. Nowadays, the best way to record arterial BP is using telemetry, although this technique is very expensive.

  • Sabahuddin Ahmad added an answer in Autodock:
    Is multi core calculation/simulation possible in AutoDock (v4) module?

    Autodock is widely accepted program to perform small molecule docking. Unfortunately, this program uses a single core, while other core of the machine remains idle. This way, we are not able to completely utilize the machine (computer's) resource. If all the cores of the machine could be used by autodock module, it would be time saving method to utilise maximum of computational resource.

    Please advise for any possible procedure/method/script to utilise maximum computer resource during AutoDock simulations.

    Sabahuddin Ahmad

    Thank you Prof. Ishikawa. It helps.

  • Sabraz Nawaz Samsudeen added an answer in Adaptability:
    How can we measure the relationship between organizational adaptability and adoption of information technology?

    Small and Medium Sized organizations do not fully embrace information technology (IT) because of many reasons hence they adopt certain level of IT. The degree of organization's adaptability may have some relationship or impact on such level of adaptability. How can we measure it? Any particular references, please?

    Sabraz Nawaz Samsudeen

    Thanks so much, sir.

  • Ajay Saini added an answer in Transferases:
    Does anyone have a protocol to label DNA with Terminal Deoxynucleotidyl Transferase?

    I need to incorporate FITC-dUTP to my DNA sample in a different way than Nick translation or PCR. Does anyone have experience with this enzyme and, better yet a protocol?.

    Ajay Saini


    You may also try protocol of TDT from invitrogen kits..

  • Amir Ehsan Ranginkaman added an answer in Convergence:
    How do I prevent premature convergence?


    I used ABC algorithm.I know that is good at exploration but poor at exploitation. so I used a method to improve its convergence but it gets stuck in premature convergence ?! which techniques are useful to prevent this problem. and How Can I create a appropriate balance between appropriate and exploration.


  • Hugo P. Van Landeghem added an answer in Steelmaking:
    Any Advice How different elements effect of prodaction of steel?

    Any Advice How different elemnts effect of prodaction of steel?

    Hugo P. Van Landeghem

    Hi Friba,

    That is a rather broad question as: a) there are many different alloying elements commonly used in steel (interstitials: C, N, B,... and substitutionals: Cr, Ni, Mo) and b) they can affect many different aspects of steel production (liquid processing, casting, thermo-mechanical processing...). You might want to narrow that down a little bit (specific elements, specific effect) so that someone can give you a really helpful answer.

  • Yopie Yutama Surbakti asked a question in Acoustics:
    How can I measure the richness of vehicle sound based on the physical acoustics properties?

    Basically, I want to prove that subjective measurement of vehicle sound's richness with appropriate objective measurement.

  • Harekrishna Misra added an answer in Collaborative Learning:
    Should the "Facilitator" be knowledgeable in a learning environment?

    Teachers, academia, market players and students collaborate in learning process through exchange of ideas, facts, and at times experiential viewpoints. As regards learning of the students, normally "facilitators" come in who create and nurture repository and establish environment for "guided"  learning in a classroom environment irrespective of its form  (digital, broadcast, multicast, uni cast, physical set up). So, is it necessary that the facilitator should be knowledgeable enough to handle such critical process!

    Harekrishna Misra

    Yes, Dr. Christa, teachers need to be the first level of facilitators, but there are other layers who may be the designers, content developers, publishers, technology solution providers......

  • Stoyan Andreev added an answer in Impedance:
    Any advice on impedance functions with negative Re and Im parts?

    When calculating foundation impedance functions in the frequency domain (with SASSI or Wolf's Cone Method) for some frequency intervals (usually between 5 and 10 Hz) the Re and Im parts become negative. This is more pronounced for layered sites and embedded foundations. Is there a physical explanation or it is a numerical issue? If it's numerical, what Re and Im values should be used instead of these negatives?

    Stoyan Andreev

    https://goo.gl/zOjqyq На страница 1374 - точно под формула 26b.

  • Panchatcharam Mariappan added an answer in Matrix Theory:
    Is there any conclusion on whether a symmetric matrix with zero diagonal entries is positive definite or not?

    Say A=B*B^H (^H means conjugate transition)

    C=A - (diagonal of A). 

    So C is a symmetric matrix which diagonal entries are all 0. 

    I wondering whether there is any study on how to judge C is positive definite, or not


    Happy Thanksgiving!

    Panchatcharam Mariappan

    Dear Jeffery: Thanks for the clarification and detailed answer.

  • Natalia D Kreshchenko added an answer in Immunofluorescence Staining:
    How can I remove gelatin from glass slides prior to immunofluorescent staining?


    I am staining cryosections of zebrafish brains embedded in gelatin. Right now I have the problem that some gelatin remains inside the ventricles and around the brain after the staining, giving a slight but very unaesthetic background signal.

    Does anybody have a suggestion how to remove the residual gelatin from the slides?

    I am using usual glass slides, an in situ labeling was performed prior to the immunofluorescent staining, I am washing with PBT (0.1% Tween), blocking with PBT (0.025% Triton, 2%BSA, 2% NGS). I already tried to remove the gelatin by dipping the slide into 40°C / 50°C heated PBT for 30s. This solves my gelatin-problem but destroys the tissue...

    Natalia D Kreshchenko

    I would say you don't need to remove gelatin frpm slodes for immunocytochemistry.

     For what? If gelatin was pure and good quality - there will not be any unspecific stainings on slide. I was using such slides without any problems. Do you have unspecific stains??

  • Ajay Saini added an answer in Agrobacterium:
    Problem in transforming Agrobacterium GV3101

    I am transforming Agrobacterium GV3010 competent cells with the plasmid after Gateway cloning(after LR reaction) by electroporation but after transformation I am getting bacterial lawn in next 12 hours only.Please suggest me why is it like that as Agrobacterium needs atleast 24 hrs to grow.

    Ajay Saini


    This might be due to large numbers of cells and less effective antibiotic. You may please check your antibiotic stock..it it is old replace it....this may be one of the reason

  • Muris Korkaric added an answer in Sugarcane:
    How do I concentrate sugarcane juice?

    what is the temperature and time required for concentrating?

    Muris Korkaric

    You should be a bit more specific. Generally, the higher the temperature, the faster you will evaporate water from juice. However, high temperatures will have an impact on the chemical components in the juice. E.g. do you care about the stability of vitamins at higher temperatures. You might also induce caramelisation of sugar at higher temperatures. As far as I know, that is why the industry used vacuum to remove excess solvent or water from juice when producing sugar.

  • Ajay Saini added an answer in Primer:
    Anybody know are there some PCR-PRIMERS specific for rye 2R, 4R and 7R chromosome, respectively?

    we want to find some primers specific for different rye chromosome, anybody can give me some information about it?

    Ajay Saini


    Many of the Rye chromosomal fragments have been used in wheat breeding programs. and for many of them markers are available..you can check if markers are available for theses regions also in MASWHeat database

  • Xiaojing Tang added an answer in Euchromatin:
    Are the results of chromosome banding all the same in different tissues?

    We know that many genes are expressed in a tissue-specific manner. Mechanisms include the remodeling of heterochomatin and euchromatin. I wonder now  if there's any way of high-resolution chromosome banding could show such difference? Or is there any other ways of staining could indicate that one gene is located in heterochromatin or euchromatin?


    Xiaojing Tang

    I‘m very grateful for all your help! Thank everyone!

  • Balavigneswaran Karthikeyan asked a question in Docetaxel:
    How one should conduct in vitro drug release study when the drug is not soluble in Phosphate buffer?

    I would like to study the docetaxel release from Nanofibers/3D Scaffolds where docetaxel is not soluble in water so which is the preferable medium to conduct in vitro drug release study at pH 7.4. Can someone help me out?