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

  • Josselyn Mena asked a question in RACE:
    What is the students attachment and the engaged of the role of race and ethnicity?

    i want details?

  • Montserrat Hernández-López added an answer in Wisdom:
    What is wisdom?

    Philosophic, religious, and opinion responses are acceptable.

    Montserrat Hernández-López

    Dear Mariano

    In my opinion, wisdom is knowing what you do not know and accept that maybe the only thing we can do with ignorance is learning to live aware of it.


  • Kamil Krumal added an answer in Decanoic Acids:
    Can I use heptanoic acid as a standard to quantify n-alkanoic acids in air samples PM10, collected on quartz fiber filter paper?

    I am doing analysis of PM10 collected on Quartz fiber filter.I am expecting organic compounds like n-alkanoic acids decanoic acid, dodecanoic acid etc...I have only one standard that is Heptadecanoic acid.Could i use this chemical for quantify all the acids by making calibration curve from this standard.

    Kamil Krumal

    Hi Sarika,

    I dont think so. I analysed monocarboxylic acids (C8 - C20) 5 years ago. I derivatized them into methyl esters by BF3/methanol and the peak area was different for different acids. The peak area of C16 was the biggest.

    Rastislav.... PM10 means particles less than 10 micrometers. PM is Particulate Matter.

  • Lilliana Ramos-Collado added an answer in Fitness:
    What is your definition of 'fitness'?

    It's all in the question


    Lilliana Ramos-Collado

    Here it is:

  • José Eduardo Jorge added an answer in Microcephaly:
    Do you think the Zika virus leads to microcephaly?

    How good is the science linking the Vika virus to microcephaly and other neurological defects in babies?

    José Eduardo Jorge

    Dear Brenda:

    This is not my field at all, but in Argentina there are lots of news on zika in Brazil -where many Argentinians usually go for summer vacations (it is summer here)- and all the information underlines that microcephaly has been clearly associated with zika, to a point that some people advise pregnant women -I think with less of three months of pregnancy- not to travel to risk zones. 

  • Ali Bni Lam asked a question in Islamic Banking:
    Islamic banking properties ?

    What is the main difference between Islamic banks and commercial banks ?

  • Mike Reich added an answer in Poland:
    Can somebody provide me a stratigraphic column of Holy Cross Mountains of Central Ppland?

    I'm in need of a stratigraphic column of Holy cross mountains in Poland. I want to have a lithostrat column that displays all rock units in Kielce and Lysogory regions. There are some papers but I could not compile column of each region separately. 

    I would be grateful if someone give me a link or a paper or a map that I can get what I'm looking for. 

    Thanks for your concerns. 



    Mike Reich

    Hello Karwan,

    You may try:

    Malec, J. (1993): Upper Silurian and Lower Devonian in the western Holy Cross Mts. Geological Quarterly 37 (4): 501-536.

    Wójcik, K. (2015): The uppermost Emsian and lower Eifelian in the Kielce Region of the Holy Cross Mts. Part I: Lithostratigraphy. Acta Geologica Polonica 65 (2): 141-191.

    or the more general overview in AAPG Memoir 84 published in 2006 ...

    Best wishes, Mike

  • Gloria Latham added an answer in Creativity:
    How to innovative new things or new ideas?

    How to increase creativity, imagination and innovative ideas or innovative things?

    Gloria Latham

    Han Ping's 3rd response is so important. Once you move out of your area of expertise, you make discoveries but also create new partnerships, new synergies, new connections. Connect with people who view the world differently

    Ask 'Why' and 'What if?'

    Look for what is missing rather than what is there. Look closely at the spaces between things

    Be playful, tinker with ideas, make mistakes, make messes take risks as Ian and Han Ping suggest

    Be surprised by small things you observe or hear or touch

    Unlearn your schooling

  • Jamila Jaganjac added an answer in Entrepreneurial Skills:
    How do I measure/asses entrepreneurial skills/competencies of university students?

    Published research on this will be helpful.

    Jamila Jaganjac

    You can asses entrepreneurial skills/competencies of university students by giving them practical task: 1. to prepare business plan for start-up company, 2. make competition within the group; 3. make notes on the best ideas and solutions, bearing in mind that the idea is realizable; 4. make them vote for the best business plan, with the explanations, why is that plan the best for them 5. go through the best business plan and identify the best parts (financial, human resoures, organisation, marketing, networking, market research etc). 

  • Motasem Saidan added an answer in Cellulose:
    How to pretreat paper mill waste (cellulosic waste with higher ash, moisture and static energy) avoiding agglomeration to reach low particle sizes?

    Dear all:

    I have a question about paper mill waste. This byproduct is a cellulosic waste with higher content of ash and moisture.

    We have had problems grinding this dry waste due to its static energy. After grinding the solid waste, the particles are agglomerated; therefore this situation avoid to feed a fluidized reactor.

    So, I would like to know if anyone knows how to pretreat the waste avoiding the agglomeration for reaching low particle sizes that can be fed in a fluidized reactor?

    Thank you in advance for your attention and guidance.

    Juan F. Pérez

    Motasem Saidan

    What is the treatement method you are using by utilizing fluidized bed reactor?

  • Sajad Alipour asked a question in Fritillaria:
    What is the best protocol for Fritillaria spp seed disinfection in tissue culture?

    seed Fritillaria spp collocated of Natural habitat(wildflower) 

  • Abubaker Elshiekh Abdelrahman added an answer in Spray Pyrolysis:
    Does the thin film thickness effect optical band gab?

    For during my work I observed that effect of the thickness on the band gap of Zn0.2Cd0.8S films decreases with the increase of the film thickness from 260 nm to 480 nm?

    Abubaker Elshiekh Abdelrahman

     Also you can see my paper about  the optical property of thin film

  • Beladel Abdelkader added an answer in Multilevel Inverters:
    How to make objective function to minimize specified harmonics in multilevel inverter?

    How to make objective function to minimize specified harmonics in multilevel inverter.

    how to solve using PSO and GA

    Beladel Abdelkader

    The PSO method gives the lower  THD compared to the other classical Iterative methods

  • George Jacob asked a question in Free Will:
    What are the free certified online courses?

    Free certified online courses

  • Amota Ataneka added an answer in Homelessness:
    Can anyone please help me find where I can find a complete dataset of historical (1970-2015) homelessness population by county or by city in the U.S?

    Been browsing all these Census and HUD websites for datasets but no luck. They all have reports and even datasets but not what I am looking for. I really need to get the number of homeless people (point in time) in each county (or city and state if county-level is impossible to get) from the 1970s (or earlier) to 2015. Most of the datasets I got so far from every webpage I can google only give me pieces of that. Thank you.

    Amota Ataneka

    Thank you very much Terry, will keep in touch. All the best to you too.

  • Apostolos KOSTAS added an answer in Postgraduate Studies:
    What is your perception of the usefulness of Web 2.0 applications to facilitate collaborative learning in your university?

    I am carrying out a research on “Postgraduates’ perceptions of the usefulness of Web 2.0 applications to facilitate collaborative learning in their university". The aim of the research is to investigate which Web 2.0 tools are used generally by post graduate students of various disciplines and to assess their usefulness as well as to explore how the collaboration of knowledge can be made productive in collaborative learning.

    Apostolos KOSTAS

     I used a web 2.o platform to facilitate students teachers during practicum in my department

    Here are 2 relative articles.

    Hope find themusefull


    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: A case study research was taken place at University of the Aegean, Primary Education Dept. in order to design, operate and evaluate an ICT-based community in support of student teachers during their practicum. A Web 2.0 social network was used as a non-formal learning and collaborative space among educators and students, guided by open and closed activities. Research framework was based primarily on the exploration of reflection levels and perceptions of professional identity of student teachers during practicum, through their participation in an online community setting and secondly on evaluating the impact of Web 2.0 spaces into teacher’s practicum during an academic semester. In this paper, we discuss about the research process and setting and present some preliminary results.
      Full-text · Conference Paper · Jul 2013

    + 1 more attachment

  • Affan Safeer added an answer in Nanoparticles:
    In which solvent SnO2 nanoparticles will be dissolved?

    in which solvent SnO2 nanoparticles will be dissolved?

    Affan Safeer

    Dear Sirajul

    try dilute sulfuric acid and small quantity of Cresolsulphonic acid to dissolve SnO2. Because Cresolsulphonic acid would be minimize the further oxidation of Sn(II).

  • Naveen Kalra added an answer in Water Science:
    Does National Water Documents need to revise?

    National Water Document (NWD) of Iran was prepared more than 2 decades ago. NWD is a basis of set aside irrigation water to farmers now and we want to know it is accurate or not (Dose it change!)? Is it necessary to revise it?

    • [Show abstract] [Hide abstract]
      ABSTRACT: Abstract Human activities affect natural processes of earth these days. Water crisis and its problems are important so that experts consider recent century as century of water crisis. For this reason, it is observed that all world’s countries go to more extract and provide water resources. Strategic policies of each countries in ration to water scarcity depends on the particular circumstances of that country such as terrain, areas with water shortage, economical water resources and technical and organizational capacities. However according to increasing population pressure, combination of strategic policies to provide more water, consumption control and decrease pressure on water resources should be a priority in the long term. Circumstances of global development face to challenge of increasing population, sever need to provide food, limited water resources and cultivatable lands and etc. So that increasing water productivity is necessary and undeniable especially in agriculture as a largest consumption of country’s water resources. The other hand, optimal use of available water resources is important in order to increase production. One way to increasing water productivity related to accurate plan of using irrigation water in field and it’s based on estimation of crop water requirement or potential evapotranspiration. Due to dependency of ETo (potential evapotranspiration) to meteorological parameters, daily amount of ETo be different for each year and it’s necessary to be calculated as probabilities and level desired. At this research, daily ETo calculated for 30 years (1982-2011) and the best probability distribution function determined by fitting 65 distribution functions and after omitting time probability ETo calculated with 90%, 70% and 50% probability level. Since probability values are much more than mean values, so the confidence level is also higher. In other word, when we use ETo with 90% probability level it means we have just one year with water shortage in every 10 years thus for mean values or 50% probability level, water stress occurring every 2 years. Results of data analysis showed that total ETo of year for mean values were 1234.3 mm/year while at national water document it was considered 1109.6 mm/year. On average, mean values of ETo was 11.4% more than suggested ETo in plan of optimization of agricultural water consumption pattern, so that on most days of year (311 days), mean ETo was higher. Also results showed that total ETo with 90% probability level was 1606 mm/year and value ETo with 70% and 50% probability level was determined 1434 and 1197 mm/year respectively. Daily ETo with probability of 90% were 26% and 47% more than values of ETo with probability of 70% and 50% respectively. Also values of daily ETo with probability of 70% were 16% more that values of ETo with probability of 50%. Key words: Probability, water productivity of irrigation network, probability ETo, network’s water requirement
      No preview · Conference Paper · May 2014
    Naveen Kalra

    Masaud, what you referred that applied water use efficiency is very relevant but that efficiency value for a crop at a location will depend upon the soil texture also, which would greatly define the water holding and drainage losses, accordingly variable need of water for attaining a given value of ET for a target yield of a crop, 

    we have to take care of this aspect too.


  • Sergei A. Ostroumov added an answer in Cryopreservation:
    Do you think that cryopreservation of frozen human bodies and their returning to life is possible?

    Some people hope it is possible. Some researchers think it is a kind of mission impossible. What do you think?

    Sergei A. Ostroumov

    Omer, thank you for detailed and balanced contribution to the discussion. May I vote it up.

    Best regards and kind wishes

  • Haritha Sree Yaddanapudi added an answer in Indexing:
    Does anyone have the CIF file of Ca3Co4O9 for crystallographic indexing?
    Thanks in advance.
    Haritha Sree Yaddanapudi

    Can I borrow the Cif file of Ca3Co4O9 please?

  • Nayyar Ahmed added an answer in Asparagine:
    Can anyone recommend a good antibody for mouse and human Asparagine Synthetase?

    For Western Blotting.

    Nayyar Ahmed


  • Naveen Kalra added an answer in Water Productivity:
    Has anyone conducted water productivity calculations?

    I wanna know about different method regarding water productivity calculations.

    Naveen Kalra

    Neda, very good question raised by you, if we see the water used for one kg of rice production, it is very large, but important from food security point of view. 

    if rice yield is 6 t/ha, water through ET loss is 60 cm, means 6000 cubic meter of water per hectare. So for 1kg of rice, we need 1 cubic meter of water as ET, 1000kg of water. But for this much ET requirement we need to apply more water as drainage also is taking place, so large amount of water, but we have not to compare with water use efficiency of other sectors, as food security is the vbasic requirement

    We can easily compute the water used in a given region if we know the production of different crops in that region, on the method as indicated above


  • Dina Yaseen added an answer in SPSS:
    Please if some of my data are normality distributed and some non normality distributed, which spss test useful to use?

    I want to find the difference between my variables  (dependent samples in one independent group) and between  the groups and their samples (four groups and each group contain four samples or variables) which analysis is better?

    if I have mix data normality and non normality?

    Dina Yaseen

    Dear Mehmet ,

    Please , are you know about the correlation coefficient ?. In case i want to use spearman's correlation ?  I faced problem with arrange the data. (it should be ordinal) , what i have to do when want to know the correlation between two scale non parametric data .??  

  • Amira Akl Ahmed added an answer in International Economics:
    Can anyone obliged me with research papers on price and income elasticities in import demand?
    Amira Akl Ahmed

    Hopefully, you'll find the following sources useful



  • Bryan R Lawson added an answer in Higher Education Teaching:
    What is meant by Double loop and Single loop?

    Can you please show the difference between them? it is related to reflective practice.

    Bryan R Lawson

    in order to show the difference between choices in a multiple choice question you would be sensible to use the one way chi squared test.  This is the most conservative and sensible choice especially if you are not really genned up on statistics.  To then doemonstrate the causality for this is not a matter of statistics but of having a valid hypothesis coming from some theory that you can show is chosen most frequently across the range of questions.

  • Ardalan Seyed Vosoughi asked a question in Spine:
    Why the effect of force is different than the effect of displacement?

    I am modeling a human spine. I am applying displacement from top side and fixing the bottom and the model is working properly but when I change the displacement to concentrated force it is dying because of max penetration error and element distortion. I tried to apply very very minute amount of force which again caused my model to die. I wanted to know why the effect of force and displacement should not be the same in a model while both are at the same direction?!

  • Noelia Lorena Grosso added an answer in Cardiomyocytes:
    Lots of fibroblasts in primary cardiomyocyte culture. How to reduce it?

    While isolating primary cardiomyocytes from neonatal mice/rat, even after pre-plating the cell suspension the number of fibroblast remaining with the cardiomycoytes is very large. Iam pre-plating the cell suspension in horse serum after enzymatic digestion and leaving it for 2-3 hours in the incubator at 37 degree celcius. How can I reduce these fibroblasts in Cardiomyocyte culture without using inhibitors for fibroblast?

    Noelia Lorena Grosso

    Which culture medium do you use during those 2-3hs?

  • Sajad Alipour added an answer in Lamiaceae:
    What is the best medium for seeding and transplanting wild plants?

    Regarding family Lamiaceae, what is the best medium for seeding and transplanting wild plants?

    Sajad Alipour

    Seeds of several species of native salvia spp Iran. The seeds sown in trays that containing  coco peat + perlite(1:1) medium but contamination whit the fungal diseases. then seedling transported to  pots but contamination whit the fungal diseases. we used fungicide before seed culture. we applied  medium container ratio of 1: 1: 1 soil + sand + cocopeat in pot.

    The soil pH is 9 .

    how can reduce to 6?