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

  • What is the interpretation if marginal product of a sector is lower than that of another but its Average Productivity is greater?

    I am comparing productivities of two industries.
    APK= Average Productivity of Capital
    MPK= Marginal productivity of capital
    APL= Average productivity of labour
    MPL= marginal productivity of labour. 1 and 2 are the two industries/firms.

    I have got the following results:

    1) APK1 >APK2
    2) APL1<APL2
    7) MPK1>MPK2
    8) MPL1>MPL2

    What is the interpretation of the above results? Which industry/business is more productive and should be promoted? 

    Krishnan Umachandran · Professor

    Productivity isn’t everything, but in the long run it is almost everything. A country’s ability
    to improve its standard of living over time depends almost entirely on its ability to raise
    its output per worker” - Paul Krugman

    Specific actions can promote one type of productivity and have an adverse effect on the other. The more intensive use of one substitute input which increases production and thus average labor productivity, can at the same time have a negative impact on the marginal productivity of labor.

  • Jamal Alizadeh added an answer in TiO2:
    Could anyone suggest papers on only interstitially nitrogen-doped TiO2?

    Could you provide DOIs of papers on only interstitially nitrogen-doped TiO2? I need that the concentration of Ni was given there, as well as the absorbance spectrum.

    Jamal Alizadeh · Amirkabir University of Technology




  • Amipara Manilal D added an answer in Antenna:
    How does meandering excited patch surface current path in the antenna radiation patch lowers the resonance frequency ? What is the physics behind it?

    Researchers & Faculty members in the field of Antenna

    Amipara Manilal D · Balaji Institute of Engineering & technology, Junagadh

    Meandering of a path of EM signal creates perturbation and slower the velocity or in other word as if physical length is more. This results in rise of distributed reactive components (L & C). Frequency of resonance has an inverse (sqrt precisely) relation with reactive components. Thus, it lowers the resonance  

  • Bipin Lade asked a question in Green Synthesis:
    Does any one have good scientific review papers on green synthesis of silver nanoparticles?

    full text is needed!

  • John George Hardy added an answer in Hydrogel:
    Does anyone have the UV absorbance spectrum of a photo-initiator Irgacure 2959?

    I have read some articles that mentioning using photo-initiator Irgacure 2959 during UV-crosslinking of hydrogel at 365nm, does anyone have any spectrum that indicates the maximum UV absorbance of Irgacure 2959 fall on 365nm?

  • Pooja Jardosh added an answer in Sampling:
    Can anyone help me regarding Apriori algorithm enhancement ?

    I am not able to find Apriori algorithm with boolean matrix generation algorithm.CAn anyone provide me code for it?

    My second question is,using sampling technique ,if accuracy doesn't fall then,the algorithm with sampling of original algorithm can be called as enhanced algorithm??for my research?

    Pooja Jardosh · Charotar University of Science and Technology

    Of course you may share your ideas...



  • Sayed Zaheen Alam added an answer in Pensions:
    Is caring for pensioners (retirees) a state responsibility or a personal responsibility?
    Pensioners served their country and people for many years. Who should take care of them? Do they need to plan their retirement on their own, or should the government take care of them?
    Sayed Zaheen Alam · University of Delhi

    Family member, relatives,

    Institution in which whole “working/economically productive life is invested” (and his own PF account ),
    “Directive Principle of State Policy” for old age in India (http://www.archive.india.gov.in/knowindia/profile.php?id=18).
    And collective responsibility as responsible neighbor.


  • Lior Kornblum added an answer in XPS:
    Ti3+-doped TiO2. Concentration of Ti3+ states?

    Could you provide a paper in which the concentration of Ti3+ states that are  presumably responsible for the shift to the visible region, is given? As I know they are not seen by XPS. How can we measure them?

    Lior Kornblum · Yale University

    Now it is more clear that by measure you mean quantify. I addressed this in my original response as well. Good luck.

  • Yuan-Yeu Yau added an answer in DNA Extraction:
    Why some time after DNA extraction there is no band in electrophoresis?

    I extracted DNA from bacteria by using extraction Kit, by when I run the DNA on agarose gel no DNA band detected, but when I did the PCR reaction I got good result. And when I run it on agarose gel I got good bands?

    Yuan-Yeu Yau · Northeastern State University

    Hi Mushtaq,

    Yes, you can get same-sized PCR products from PCR tubes you add their genomic DNA in.

    The 'negative control' tube is set up without any DNA template. If negative control is amplified, what do you think what has happened? An 'un-intended' DNA template accidentally 'falls' into the tube. We call this 'contamination'. Since even the negative control can be amplified with an expected PCR product, can you trust the PCR bands from the other 'sample' tubes? Because they may also result from the same 'contaminant DNA template', not from your gDNA sample. So, set up a negative control in PCR experiment is very important.

  • Who is interested in helping to compile and map a global fault zone permeability database?

    I am compiling global database on fault zone permeability, in rocks, any depth. Looking for hard to find data: tunnels (engineering reports), anything not published in journal papers or not in major repository studies.  I have >1000 publications but some regions are under represented, especially anything not in English.

    Ouerdachi Lahbassi · Badji Mokhtar - Annaba University

    IT'S very difficulty for find the data. Actually, we-have Perhaps luck with
    the construction of the East-West Highway (Algeria) /
    if you'll give me more details

  • What is the use of Hessian in computational chemistry?

    Couldn't figure out the use of the Hessian matrix in computational chemistry.

  • Are you also thinking - the more knowledge is produced by mankind - the greater gets the gap between rich and poor people?

    Or do you more think like the saying from the Austrian writer Marie von Ebner-Eschenbach, who said: Who stops to try to get better, stops being good. Isnt this the human driving force of scientists and commerce and finally but the original source and gap-maker and between between rich and poor people?

    In the last years this question I am asking me always more since I am studing also philosophy and neuroscience.

    I put Marie von Ebner-Eschenbachs saying on my homepage for bettering our grassland and rangland in Austria as my driving force. But I think also, when all would do this we get a huge overproduction of milk and meat. The following consequence would be decline of milk and meat price so that nothing is gained or won. And we would find more pesticide and unused fertilzers residues in our enviroment. The agricultural intensification causes a worse environment by a reduced grassland and rangeland plant biodiversity by more monotonous culture land.

    How do think about this gap and at which side are you?

  • Cheng Wei added an answer in Gas Flow:
    How can I define and extract the side-blown jet penetration depth?

    In the side-blown flowing process, with the increasing of gas flow, the gas flow regime will be jet flow, the jet flow is shown in figure 1. However, how do you define and extract the side-blown jet penetration depth?

    Cheng Wei · Central South University

    thank you very much for you reply. the method you supported must be a excellent way to calculate it. by the way, there is another question, how can i define the very side-blown penetration depth? i can not find the theoretical support or the empircal formula. 

  • Which one of the P25 TiO2 and the ZnO is more suitable photocatalytic material from the cost and the performance point of view for water purification?

    Nano and Micro size particles of P25 TiO2and ZnO semiconductors have nearly same bandwidth and often used for their comparative studies for water purification application for hazardous heavy metals for health, such as As, Cr, dyes, and even E-Coli bacteria. Could someone kindly throw more light on this subject to clearly  understand and conclude which one of these two photo catalysts is more suitable from the points of views as follows: over all performance, health, safety, system cost, sludge management, environment friendly, material reuse life, etc. Best regards.

    Jamal Alizadeh · Amirkabir University of Technology

    In photocatalysis, TiO2 has been studied extensively because of its high activity, desirable physical and chemical properties, non toxic,low cost, and availability.

  • Alka Madaan added an answer in HaCaT:
    Has anyone studied IL-20 expression in any cell line?

    Does HaCaT secrete this cytokine? What stimulus should be used?

    Alka Madaan · Dabur Research Foundation

    thanks for the article Nurul

  • N.Subash Chandra Bose Raju asked a question in NCBI:
    Can you please suggest me Where can I get reference sequence for 16srDNA?

    I have analyzed gut flora of Helicoverpa and found out with some strain identification  by 16srDNA analysis such as B.pumilius etc. I want to check these strains via  nucleotide diversity by DNA sp software. I am looking reference sequences of  16sr DNA  of those strains. Can you please suggest me other than NCBI data base for getting reference sequences for diversity analysis of these strains.

  • Nattan Stalin added an answer in Phage:
    Could anyone suggest me a method for purifying phages particles in the SM buffer for TEM analysis ?

    I performed TEM analysis for my bacteriohage.repetitively I got only salts images how to avoid the presence of salts during TEM analysis.

    Nattan Stalin · Department of Bioinformatics

    Thank you for your help,

    Please give me detailed procedure with reference articles


  • James R Knaub added an answer in Organizations:
    When there is employee silence, no culture of respect towards the employees is observed then how the organizations retains its potential employees?

    When there is employee silence, no culture of respect towards the employees is observed, no participative management, then how the organizations retains its potential employees and become World's No.1. Kindly suggest me based on research or experience.

    James R Knaub · Energy Information Administration

    Sujata -

    If management were more concerned with retaining good employees, that would be a big improvement. But people too often find their way into management, perhaps especially in organizations that should be more scientifically oriented, who are not even familiar with the purpose of that organization, nor do they have the knowledge and skills necessary to make good decisions. I think the concept of the clueless supervisor, who is an impediment one must work around to get things done, is all too familiar.

    This real-life obstacle is common enough everywhere that it is reflected in popular fictional literature, such as the "Brunetti" series of books by Donna Leon, and the depiction of the farcical office in the "Dilbert" comic strips. This theme is found in many movies and TV series as well. A big reason for this is that it is far too often too close to the truth. Art reflects life.

    In the world today, high unemployment, caused largely by foolish/ignorant and greedy management, has made it easier for those most responsible for causing economic problems to remain those making the decisions, while many employees are working for minimum wage and trying not to join the unemployed. It is far too common that the wrong people have too much control. (This is an old theme. See Samuel L. Clemens' Connecticut Yankee in King Arthur's Court.)

    Too often, the best way for employees to get into trouble is to try to do their jobs.

    So assuming that an organization even wants to retain good employees assumes a great deal that is good about that organization. But office politics, as in governmental politics, often undermines any good sense, and can make employee retention a moot point. It often just is not a concern.


  • Prakash Dattatray Raut asked a question in BOD:
    I wish to know the relation of water parameters with each other?

    Water monitoring is becoming a very crucial task due to increasing pollution at various water sources. The parameters for various waters like drinking water, sewage water, industrial effluent are showing variations. I would like to understand the exact relationship of these parameters with respect to the source of water. The parameters are DO, BOD, COD, EC, TS, TSS, TDS, Hardness, Nitrates, Phosphates etc. I mean how DO, BOd and COD are related or how EC, TS, TDS and TDS are related.

  • How to run a meta-analysis of medians and IQR?
    I'm involved in a meta-analysis where some trials outcomes are shown in mean and standard deviation and some are shown as median and inter-quantile range. As softwares' functions require the group n, mean and SD, I looked around and found the following paper http://www.biomedcentral.com/1471-2288/5/13. However, this simulations study states that it is possible to estimate mean and SD given the median and range (min and max values), not from median and IQR. We checked again on each paper for min and max value but it was very disappointing as none informed these values. Therefore, I would like very much if any one have a tip to help me workaround this issue.
    Ahmed Negida · Faculty of medicine, Zagazig University, Egypt


    Simply to solve this problem, i calculate the HR from the 2 medians when they -only- are available. Refer to the following article:

  • Jenkins Macedo added an answer in Research Papers:
    Can we define an expiration date or useful age for our papers?
    Is it reasonable to use these terms?
    A number of papers have been published a long time ago, but still have many citations.
    If it is possible, then is it predictable?
    Is citation can be a suitable measure to judge the useful age of a paper?
    Which papers have more useful lifetime or long expire date?

    Thanks for your inputs.
    Jenkins Macedo · Clark University

    If you are doing agronomic field research, some of the methodological sound and statistical procedure papers are older. Surely, recent papers are great to cite, but older ones with grounded knowledge always have their unique role to cement your point. In my opinion, saying that papers expires makes no sense or else literature review would be totally worthless.

  • Asaad Javaid Mirza asked a question in Dental Science:
    How can vertical integration be applied in teaching of preclinical dental students?

    Vertical integration is combining knowledge of basic medical/ dental sciences with clinical sciences. Dental students go to clinics in 3rd year of their education. How can clinical knowledge be imparted to Preclinical dental students. 

  • Azimun Nahar added an answer in Food Microbiology:
    Which factors can affect the survivability of E.coli in orange juice?

    I inoculated E.coli C600 in orange juice but it can survive until 6-9 days. Why?

    Azimun Nahar · Bangladesh Agricultural University

    @ Jharna, Thank you very much for valuable suggestions and some basic questions regarding my experiment.  I am really seeking for these information to conduct my research under comparatively standard condition.I would like to inform you that 1. I used Orange juice bought from supermarket and before inoculation I checked any contamination by spreading of juice on LB plate and found no contamination. 2.  Before inoculation, I checked pH of the Juice and continued to check it every sampling time. 3. Before conducting this study ( Survival ability of E.coli 0104 and as a control O157 and C600 in orange juice, pH 4.0-5.0), I already checked one time survival ability of those three strains of E.coli in citric acid hydrogen phosphate buffer ( pH 5.0). Still do you think I need to inoculate of those 3 strains in the same time in orange juice and peptone water and  as I checked pH of orange juice before and after inoculation of bacteria, still I need to keep uninoculated  orange juice along with them. Please give me your opinion and suggestion which are really necessary for my experiment.

    Sorry for any inconvenience.

    Best regards


  • Maryam Chilan added an answer in Patch Antenna:
    What do I do for defining waveguide ports to design a patch antenna in cstmws with cpw structure?

    In cstmws it is mentioned that we have to use pick points on outward conductor but it shows error. How exactly do you feed this type of antenna structure?

    Maryam Chilan · Tarbiat Modares University

    would you please describe the error?

  • How can one solve the inhomogeneous complex nonlinear equation?

    I am attempting to solve the complex nonlinear equation with space dependent variable coefficients. The usual algebraic methods say jacobi elliptic, tanh, sine-cosine etc couldn't work for this equation and also many variable coefficient nonlinear equations I came across so far are time dependent which can be easily solvable and methods are available. I do no have knowledge on Lie symmetries. (See the file attached). Thanks in well advance.

    Saravanan Manickam · Saveetha University

    yes  generalized solution. In case if possible for solution through expansion or perturbation, that too I acept. The equation I shown is first order perturbed fields of magnetization for a ferromagnetic medium. I am expecting soliton solutions because this eq is just extended form of integrable derivative NLS equation when the variable coefficient f and h are zero.

  • Emil Björnson added an answer in LTE:
    How can the channel capacity be equalized along the radius of the cell in LTE?

    The channel capacity decreases with distance from the base station as a consequence of the the decreasing the signal to noise ratio in LTE systems. At the cell boundary, normally Bpsk modulation is used while the order of modulation may increase to 64 QAM or more near the center of the cell. This means a bandwidth efficiency increase of about five times from the cell boundary to the cell center.

    So, the subscribers at the cell center are better served than those at the cell boundary. My question is how would the channel capacity be equalized among the the distance from the cell center? 

    Emil Björnson · Linköping University

    I would say that relays are good at providing range expansion, but less suited to equalize the throughput over the cell. This is because the two-hop transmission in relaying cuts the throughput in half. Hence, even if you can give the same SINR everywhere, you will get a data rate at the cell edge that is only 50% of the cell center.

  • Sayed Zaheen Alam added an answer in Universities:
    If you are a university leader, what you will do to promote your university?
    There are many challenges issues faces university leaders to promote their university. These challenges are local, regional and international
    Sayed Zaheen Alam · University of Delhi

    Listening, dialogue, encouragement without any personal political motive/affiliations/pressure/interests  in my University (infrastructure, publications and staff is already one of the best).


  • Vladimir K Ivanov added an answer in Cerium:
    Can we obtain cerium oxide nanopaticle with the addition of hydrogen peroxide to cerium nitrate? is it essential to use a base like ammonia ?

    chemistry,chemical engineering,nanomaterial

    Vladimir K Ivanov · Russian Academy of Sciences

    Dear Sridhar,

    ammonia is NOT a reducing agent. Moreover, to obtain CeO2 from Ce(NO3)3 you need to use an OXIDIZNG, not a REDUCING agent. You can find this information in any  textbook on chemistry.

  • Salam Nazhan Ahmed added an answer in Laser:
    Why we have increase in output power by increasing pump current in diode laser?

    By increasing the pump current in diode laser, we see increasing in output power.

    This relation is linear.

    Why we have this?

    Salam Nazhan Ahmed · Northumbria University

    Dear Parviz Parvin, you are absolutely right, however, these effects causes distortion in the laser beam and then efficiency factor

  • Raghu Ram Achar added an answer in Catalase:
    Why can I not detect a catalase-peroxidase by zymography that I can detect phenotypically?

    I'm able to detect phenotypic differences among mutant strains lacking one or two catalases, but when I try to detect individual catalase activities by zymography after native PAGE, I'm only detecting one band, corresponding to one of the catalases. The other one has been annotated as a catalase-peroxidase, but I'm not able to detect either the catalase or the peroxidase activity after native PAGE. To develop peroxidase activity I've tried different substrates, including DAB, ABTS, TMB and 3-amino-9-ethylcarbazole. but I only detect the positive control (HRP), regardless the substrate employed. Anyone has a clue what's happening?

    Raghu Ram Achar · Sri Jayachamarajendra College of Engineering

    I suggest you to incubate the gels in different buffers to get activity.