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  • Amr Abdulfattah Hassan asked a question in MATLAB:
    Any one have open source vedio to show how can we make clusters by Matlab?

    Matlab, nural networks , cluster

  • Biswa Prakash Patra asked a question in Thermometers:
    How to calculate P with Grt+Ortho/Clinopx+Plagioclase thermometer and T with Grt+ Ortho/Clino px thermometer? Only EPMA analysis is available.

    From EPMA analysis, I have done cation calculation and also have done end-member calculation for Garnet , Orthopyroxene, Clinopyroxene, Plagioclase . From this calculation how do I calculate Pressure and Temperature condition of basic granulite rock ? 

  • Stefan Wirtz asked a question in Publications:
    I am looking for publications in the field of pose reconstruction using only a single image. Do anybody have some recommendations?

    I want to reconstruct the pose of a rigid object using only one single image and a model of the object which contains semantic and geometric information.

  • Azam Goncheh asked a question in Teaching English:
    Is there any source I can use to teach English humor in my class?

    I want to teach English humor, as treatment for my research, and I need some good books or articles that can guide me what to teach.

  • Amer Al-ani added an answer in Turbulent Flow:
    Entropy Generation Equation ?


    Please, could anyone give me the entropy generation equation for turbulent flow forced heat transfer, 3D, and steady state.


    Amer Al-ani · University of Leeds

    thanks a lot.

    Ashish Kotwal ,, I need Entropy Generation Equation no momentum, energy, and continuity equations.

  • Imtiyaz Khan asked a question in Pi:
    How to define cyclic frequency for cyclostationary signal in terms of signal parametrs?

    I am trying to detect cyclostationary signal. For that it is required to know its cyclic frequency. But I am unable to figure out how it can be related to signal parameter. Is it possible to define exact value of cyclic frequency or its a range of value in which it can exist.

    Suppose we have amplitude modulated signal

    • dt=0.01;
    • fs=1/dt;
    • fm=1;
    • fc=30;
    • t=0:dt:1-0.01;
    • A=2;
    • n=length(t);
    • mt=sqrt(2)*cos(2*pi*fm*t);
    • S=(A+mt).*cos(2*pi*fc*t);

    Now I want to know how to define cyclic frequency suppose alpha for the above signal in terms of signal parameters.

  • Volker Lohweg added an answer in Image Processing:
    What are the recent areas in image processing for a Ph.D.?

    I have finished my m. tech and now I am interested in a Ph. D. Can somebody help me to find a research area? or pls u can send me on email if khadebeena@gmail.com

    Volker Lohweg · Hochschule Ostwestfalen-Lippe

    This question is a little bit weird. Image processing is a huge field. Therefore, you have to ask yourself what are open research questions in a certain field which was not tackled up to now.

    Open research questions we have, e.g. in Belief networks for image processing; spectral decomposition for images in the context of Big Data; Fast learning and classification in Robotics, etc, etc, etc.

    My recommendation to you is, ask yourself what are your interests first(!) and where you can contribute(!) to the image processing community and then talk to your Prof. If He/She leads a powerful research group they have many topics available which might correlate to your interests.

  • Peter Saling added an answer in Energy Modeling:
    What about the integration of sustainability indicators in energy systems optimisation models?

    For energy modellers, first idea is using externalities (extra costs in the objective function) but what's the point for the LCA modellers? Evolutive environmental profiles? 

    Peter Saling · BASF SE

    Energy parameters should be linked with CO2 and acidfication figures along the whole life cycle of fuels. They can be normalized and aggregated to a single score using distance to ttarget approaches as well.

  • Does anyone know how to determine building density zoning in a comprehensive plan?

    I want to pathology the method of determination of building density zoning in my country (Iran) when we provide a comprehensive plan for a city. Thus, i want to know, does anyone know how to determine building density zoning in a comprehensive plan? What is the universal method for it in developed countries or developing countries? Can you introduce any book or article or research?

    SAJJAD F. ZADEH · University of Tehran

    Dear Faysal

    Thanks for your reply

    I agree too, this method is not a good practice because it ignores a lot of aspects of sustainability, especially carrying capacity of lands.

  • What would you define a small satellite as?

    I'm doing a project on optical communications between small satellites, however, I feel the general term given by Wertz of up to 500kg/1000lbs is quite vague and seems somewhat unnecessarily large. Using the http://satellitedebris.net/Database/UCSDB.php I found that out of the 1,000 odd satellites listed 568 had civil and/or commerical users and the mass ranged from 0.8kg to 6,910kg. 145 of those satellites were under 500kg, but, it seemed to jump to 689kg and above, leaving no medium/middle sized satellites. I would therefore, suggest saying less than 300kg. Additionally, Straub, J(2015) mentioned in his article In Search of Standards for the Operation of Small Satellites that only 14% of the university Cubesats were greater than 40kg. It just seems quite out of proportion to the advancements we have today to say 500kg is small.

    Do you agree? Disagree? What is your opinion of this?

    Susie Cumberland · Cranfield University

    Thank you for your answer, I find this interesting. I am inclined to agree with your point here.

  • Vladimir Krapivin added an answer in Ectoparasites:
    Please identify this species of ectoparasite?

    Parasite from Berylmys

    Vladimir Krapivin · Saint Petersburg State University

    These are some false scorpions, Pseudoscorpionida. They are not truly parasites, having phoretic association with some invertebrates and vertebrates (do not feed on the host, use it just for distribution). 

  • Mandana Donoghue added an answer in T-Test:
    Statistically, can T test be used to examine a study hypothesis?

    any answers are highly appreciated

    Mandana Donoghue · OMFP center

    Many interesting answers . 

    T test leads to a P value to ascertain the  probability  of the  null hypothesis being rejected outside a chance occurrence, it can not really test the hypothesis, since it is meant to only test its probability, which, is  the reason , an insignificant finding or a p value greater than 0.05, does not mean the hypothesis is wrong it simply fails to reject the null hypothesis.

    Confidence intervals test the possibility of the test hypothesis or the alternative hypothesis being acceptable and including the mean population value 95% of the time (95%CI) again it only shows that the mean values  most likely include the population mean,  but there is no way of knowing if the hypothesis was right.

    I don't think in  biology at least there are such absolute certainties that a theory propounded today can be true for all situations and all times, which is the reason science reinvents itself everyday. 

    Hypothesis  (content) must be examined in relation to a context.

  • Why do I observe reduction in open circuit voltage of organic solar cells with annealing?

    This is regarding P3HT:PCBM bulk heterojunction organic solar cells. I have noticed that open circuit voltage is a little less for the annealed devices when compared to un-annealed devices. (of course the performance improves with annealing, with significant enhancements in Jsc and fill factor). I want to know if this is a well known scenario, and if so what can be the reason for this. Is this common to other polymer blends as well?

    Thank you.

    Imalka Jayawardena · University of Surrey

    Hi Waranatha,
    Based on the details given, a Voc of 0.55 V is quite good. The reduction in Voc can be due to a number of possible reasons. For example, it has been reported in the past that P3HT tends to segregate near the surface which can result in a decrease in the Voc. another possibility is the crystallinity as explained by Ankur.

    A few inetersting points that I've noted with your process:

    1) You haven't mentioned the use of a slow drying process. I take it that you do this before you deposit the Al?

    2) In our labs, we normally thermally anneal the P3HT:PCBM layer before deposition of the contact. Not really sure if both procedures lead to same result, but might be worthwhile trying out and see how that affects the device parameters. The annealing temperature and times are different for different labs. Hopefully you have done a series of tests under different temperatures and times which has led to the number you are using. 

    3)One point I've noted is that you don't seem to have a buffer layer between Al and the active layer. Usually a thin film of BCP, Ca, LiF etc might help you to push that slightly higher. 

    Also any particular reason why you are using PC60BM instead of PC70BM (or even ICBA)?

    While in principle, the use of Al should allow you to form the required contact (at least on paper), a buffer layer usually helps to mitigate any exciton quenchign effects in the presence of a metal contact and also prevents hot metal diffusing into the device during the Al deposition. 

    Although eh above are not directly related to your original question, hope it helps

  • Can anyone recommend readings on expertise in dealing with complex dynamic systems?

    I'm interested in how experts who deal with complex non-linear multicomponent dynamic systems in their professional domain - psychotherapy, body therapy, management, systems medicine, political systems analysis - represent the systems they interact with or track its dynamics, for instance by referring it to a complex "attractor landscape" model of trade-offs and emergence. Studies of how complexity as such is conceptualized and what underlies non-mechanistic intervention strategies (foundational metaphors, cognitive architectures, etc.) is part of what interests me.

  • Hrushikesh Sable asked a question in Polarization:
    Why refractive index change with temperature ?

    Is it just that the medium becoming less dense upon increasing the temperature allows the light to travel faster? I am trying to explain using the polarisation concept. Means the refractive index is the square root of relative permittivity, so can we say the temperature changes causes changes in polarization due to increase in average expansion of charges, hence the dipole moment and thus the polarization??

  • Johannes Wöstemeyer added an answer in Primer:
    I'm looking for sequencing a short unknown fragment about 25-30 bp (cannot design primer), but the amount is abundant (nM). What method can I use?

    I'm looking for sequencing a short unknown fragment about 25-30 bp (cannot design primer), but the amount is abundant (nM). What method can I use?

    Johannes Wöstemeyer · Friedrich-Schiller-University Jena

    Do you mean a single-stranded oligonucleoteide -in that case Gilbert-Maxam-sequenceing is still an excellent option- or a double-stranded piece of DNA. In that case I need to know something about the ends in order to give you a reasonable advice.

    Best wishes - Johannes.

  • In asymmetrical ANOVA, fixed and orthogonal, which term is the Control vs others tested over?

    I have an experiment with two fixed and orthogonal factors (dose and concentration) and one control. I thought I knew how to do it, but have found contrasting literature on how to carry out the asymmetrical anova and most papers do not declare the details of how the analyses were done. Also most of the papers refer to designs with random factors, such as those in Glasby and Underwood etc and mine are all fixed. I have carried out two separate anovas, (1) one way with all treatments including control and (2) two way with dose x concentration without control. When I construct the asymmetrical anova from the two analyses, I am not sure whether to test control vs others against the res from analysis (1) or from the combined residual from (1) and (2). Any suggestions?

    José Walter Pedroza Carneiro · Universidade Estadual de Maringá

    I have found difficult to give oppinion in researchgate, because it is just an oppinion. We do not have methods neither data set. But, let's go. In my oppinion you have an experiment involvindo dose-response. In such cases there are softwares and models to analyse models suitable to describe these situations. Regression analysis is the best way out. Talking about comparison (possible zero dose and concentration), it is possible to compare the best treatments from dose and concentration with the control using orthogonal contrasts. Otherwise, I am not sure now, but every dose must have its concentration. In fact, you have to clarify in your study the terms dose, dosage and concentration before making decision. I hope the following article can help you: Urquhart, N. S. The anatomy of a study. Hortscience. 16(5): 1-5, 1981. Other possibility is to have access in the internet by typing the words "dose-response distribution" from where you can achieve definition, models and softwares. When you increase or reduce the dose, you change the variance and this fact must be considered before the conclusion. The fact may seem dificult for beginners but it is broadily studied by experts in dose-response experiments.
    I hope to have helped you.

    Best regards.


  • Does anyone know about crowd simulation in emergency situations?

    Does anyone know about the simulation of crowd in simulation. Its perspectives and technologies currently used and human behaviour in such conditions  

    Guido Francesco Villa · Azienda Ospedaliera della Provincia di Lecco

    Hi Sajid Alì,

                                 You can ask to Pier Luigi Ingrassia or look in his page for finding something of your interest. I can send to You my publication on this topic hoping it can be useful for You.

    Best Wishes,  GFV

  • Rajivgandhi Sundaram asked a question in Elution:
    How to purify protein with 27 KDa from GST ?

    Dear colleagues, i am trying to purify a protein with 26 kDa size that is expressed as a GST fusion protein. When i have done  on column GST cleavage in the flow through both GST and my protein of interest coming together. Even i tried Superdex 200 SEC there also proteins are co-eluting. My protein pI is 4.54 and GST pI is 6.09 so i did ion exchange (mono q) with buffer pH 6.5 i eluted by gradient elution with 1M NaCl but here also both the protein coming together. Please suggest some idea to purify the protein. I need this protein for crystallization and structural studies.

  • How to find the mass flow rate of the working fluid in designing simple organic rankine cycle using EES?

    I am working on feasibility analysis of ORC for waste heat recovery of SOFC-MGT hybrid system research project.

  • Are there colleagues connected to coordinaton of international mobility programs who would be interested in doing some research on this topic?

    I'd like to explore some issues related to mobility programs, namely teaching/learning methodologies, language acquisition, cross-cultural impact.

    Margarida M. Pinheiro · University of Aveiro

    Hello Claudia,

    I am not directly connected with international mobility programs but I am able to help within questionaires and data analysis. Do you think we can work together?

    Thank you

  • K.G. Mandal added an answer in Fertilizers:
    How to calculate phosphorous from P2O5 which has been recommended at the standard dose of 45 kg/ha?

    I want to use different application level of Phosphorous (o kg/ha, 45 kg/ha, 90 kg/ha, 180 kg/ha) as a fertilizer using P2O5. How to manage the application rate ?

    K.G. Mandal · Indian Council of Agricultural Research

    Dear Dr. Israr Khan

    In addition to the appropriate answers provided by Dr. Kalaivanan and Dr Vladimir, %P2O5 i.e., I would say that phosphate content in the fertilizer may be required to find out the actual amount of fertilizer to be applied at P rate 0, 45, 90 or 180 kg/ha.

  • Abdul Kayum added an answer in Medical Imaging:
    Can anybody suggest how to start the research in medical image processing?

    Hi ALL

    Plz suggest what can be done in medical image processing field.

    Abdul Kayum · Tezpur University

    Dear Pahuja, What you should do is start reading Articles in Medical image processing. Find a problem that is not addressed yet or may be a problem you feel should be better addressed. Read and read. Consult your supervisor regularly. Grow your network with other researchers. Good Luck. 

  • Sundarajan Kannan added an answer in Chlamydia:
    Are dark bubbles contamination in cell culture?

    I'm culturing 16HBE and Calu-3 cells. There are some floating dark perfectly round bubbles with brightness parts(like cell debris) in both cell lines. I inoculated the supernatant on agar plate and nothing grew. But the number of these bubbles could increase and in some flasks the media turn yellow quickly. Is it possible mycoplasma or chlamydia contamination?

    Sundarajan Kannan · Aaranya Biosciences Pvt, Ltd

    Hi Xiaobai Ji,

        Their are two possible contamination can be arrived from your statement 1) yeast growth 2) slow growing bacterial contamination, media could turn yellow along with contaminants the nutrition got depleted, Use fresh culture and also fungizones to prevent yeast contaminants

    All the best

  • Which is the best tool for performing ETL in data mining?

    ETL (Extract, Transform, Load)

    Hi there,

    Just take a look at this in addition to what Ludovic has proposed:




  • Has anyone used the fitbit accelerometer to measure physical activity in a research trial?

    Im looking for a reliable and accurate accelerometer to measure physical activity in the immediate post-operative setting - has anyone investigated the accuracy of the fitbit accelerometer, or used it in their research?

    Fabio Alexander Storm · The University of Sheffield

    Hi! We have recently published a comparison stud between 7 activity monitors, looking at step detection accuracy, including the Fitbit One, which performed well.

  • Suleman Dangor added an answer in Quran:
    What effect does zakat alms have on social welfare of the community?

    Zakat is the third pillar of Islam and it is an obligatory
    payment that a free and rational Muslim who owns a certain amount of wealth has to observe. Its importance in Islam is manifested by the numerous pairings of its obligation to that of prayer (salah) in the Quran. Among the fundamentals of Islam, it has the most direct economic implications on Muslims for it involves the distribution of wealth from the affluent in society to those in need.

    Suleman Dangor · University of KwaZulu-Natal

    The amount of Zakat payable on cash or kind is 2.5%. However, it is substantially higher for crops and cattle - ranging from 5% to 10%. Many organisations are using zakat to empower poorer communities by providing skills training and purchasing equipment that can be used to generate income. . 

  • B.P. Numbi added an answer in Power Generation:
    How can I change the nominal power of the generator DFIG and SCIG during simulation?

    My project is depend on changing the nominal power of the generators, transformer and loads during simulation But when I do it with command set_param error appear, the error is {Cannot change parameter of generator while simulation is running.) I want to change the nominal power of these block especially generators. How can I overcome of this error? 

    B.P. Numbi · University of Pretoria

    Would you please tell why do you want to change the machine nominal power?

  • Did we obliged to re-test the reliability & validity of a previous questionnaire that has been tested before ?

        In other way, the use of a previous questionnaire as a measurement tool that has been taken the reliability & validity test; does not need to make a new test of that step again.

    Otherwise, you can check more about the use of a previous tool of measurement (questionnaire), see the article attached.

    See also:


    Ronán Michael Conroy · Royal College of Surgeons in Ireland

    Reliability is a property of the test scores of a sample of a specific population as assessed in a specific context. It is not a property of a test that is independent of context.

    So you should read the test literature with caution. Different settings, different samples, different populations - different reliabilities.

    Thompson B, Vacha-Haase T: Psychometrics is Datametrics: the Test is not Reliable. Educational and Psychological Measurement 2000, 60:174–195.