Q&A

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

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
  • Can anyone suggest how to start writing MATLAB code for multicomponent distillation system (non ideal)?
    An ideal multicomponent distillation system can be solved easily using Fenske, Underwood, Gilliland and KirkBridge Equations. But, a non-ideal system has variables like activity coefficient etc which require solving of complex equations and cannot be done on a paper. So, I need help in this matter. If software other than MATLAB would suffice, then please add details about that too.
    Salvador Tututi-Avila · Rensselaer Polytechnic Institute

    I would suggest to use an equation oriented software such as gPROMS or ACM. There is a lot of information on the web about the implementation of rigorous distillation columns.

  • Why ephedrine and pseudoepherdine should be avoided in case of Thyroid diseases.

    is that linked to vasoconstriction? what are the consequences? 

    Carlos Hernandez-Cassis · University of Miami Miller School of Medicine

    Ephedrine and pseudoephedrine are adrenergic medications and thyroid hormones have mainly a Betamimetic effect specially in the heart. The pharmacological combination of both may cause palpitations and cardiac arrhythmias. The vasoconstriction is in the peripheral vascular system. In the splacnic vascular system and in the bronchial tree they have the opposite effect (vasodilation and Broncodilation).

  • Pradip Kumar Kamat asked a question in Transgenes:
    How to make efficient transgene expression in mice brain?

    Usually when we transfect the genein organism we get some time good expression some time not. Is there any precaution or protocol to make most efficient transfection and gene expression?

  • Badoc Alain added an answer in Plant Identification:
    Does somebody know this plant?

    Please help me, Thanks

    Badoc Alain · Université Victor Segalen Bordeaux 2

    It is Euphorbia marginata. The latex of this ornamental species can be dangerous on face (Contact Dermatitis 1985 13(1)44 et 1991 24(2)155 cited by http://www.euphorbia.de/res5.htm)

  • Keat Wei Loo asked a question in Citations:
    Downlod citations from JSTAGE

    How to download citations from JSTAGE (https://www.jstage.jst.go.jp/browse/-char/ja/). There is no button, option to click on. please advise

  • Jialin Wen asked a question in Force Fields:
    About the reactive force field parameters that describes the interaction between silica and water

    I'm Jialin Wen, a PHD student in Tsinghua University, Beijing, China. I have read your paper named of "A reactive molecular dynamics simulation of the silica-water interface", but I haven't found the reactive force field parameters developed by you to describe the interaction between silica and water, so where can I get them?

  • Hao Jiang added an answer in Injections:
    Does anyone have experience working with Injectable Cyanocobalamin in rats?

    I urgently need know the dose/kg for rats. There is no literature search available.

    Kindly share your expertise.

    Hao Jiang · No.1 hospital, Guangxi University of Chinese Medicine and Pharmacology

    Vitamin B12 injection dose/conc specification is 0.1mg / 1ml / Amp, For the treatment of adults (60kg) megaloblastic anemia dose is 0.1mg / d. Rats weighing in average is 300g (0.3kg). The dose of VitB12 in rats is about 10 times of the human dose.

  • Jane Bottenstein asked a question:
    How to remove requests

    How do I remove my own requests from my list?

  • Richa Sachan added an answer in Subculturing:
    How do I overcome pc3 cell from undergoing apoptosis after thawing?

    Hello, I am new to handle pc3 cell. I have thawed two times this cell, both times after thawing, the cell grows but as I subculture it the cell undergoes apoptosis. I am using RPMI 1640 as subculture media. Please suggest how I overcome this?

    Thanks

    Richa Sachan · Sungkyunkwan University

    Thanks Michael....

    I ll follow your suggestion................

  • Larry Carlson added an answer in Philosophy:
    Can ethics be measured objectively?
    Ethics, ethical committee, ethical approval and other ethical related words are extensively used on Researchgate and other places. How to define and measure ethics in objective bases?
    Larry Carlson · United Tribes Technical College

    Francesca,
    My point was not that your definitions of morality and ethics were wrong and mine were right. My point was that all such philosophical definitions, regardless of who makes them, are, to one degree or another, artificial and arbitrary; therefore we cannot draw definitive conclusions from them. For example, you state that the Golden rule is universal because it is "compatible to the Concept of universal Ethics [the Idea that there is a universally recognized Sense of Ethics, or that the ethical Principles are Something which is internationally or, so to say, universally recognized]." 

     You give no evidence to support your claim that the Golden Rule is a universal ethical principle other than your claim that all ethical systems, by definition, universally adopt the Golden Rule. This is just stating a tautology and engaging in circular reasoning.  (I would add that you do not provide evidence that all societies adopt the Golden Rule as a principle of their ethical systems, or even clarify which particular version of the Golden Rule you are applauding.)

    By the way, yes, there is a difference between spirituality and religion.  But I fail to see what difference this makes to the discussion. Spiritually minded people have historically been ruthless and murderous as well as religious people, and indeed it is difficult to make any clear cut distinction between the two in practice.


    As for your most recent claim that you weren't talking about all mankind, well, I would say you came close enough to it: Your actual words were, “I find the masculine Side here very arrogant, which is an Attitude typically associated to the so called Western Science, if not even to the so called Western World.”


    In any case, I see no justification for you to use the “gender card,” as it were, whether speaking of male scientists in the Western world, or the males who disgruntled you. I dare say that there are plenty of female scientists in the Western world who would agree that you have done little in the way of providing evidence that would be acknowledged by most scientists or philosophers, to support your claim, for example, that the physically situated heart is the seat of good.


    You previously stated, in so many words as I recall, that there was a bunch of nerves in the heart analogous to that found in the stomach and that this somehow might constitute some sort of locus of awareness, and therefore source of ethics, as the heart “is the Seat of the so called Good.”

    Of course, I can tell from the tone of your writing that you mean well, and that your "heart is in the right place," as the saying goes, buy this is all very specious reasoning in virtually any modern scientist's or philosopher's book. Again, vague poetic speculations and biological references, as well as Panglossian allusions to childhood feelings are all rather irrelevant.

  • Geng Ouyang asked a question in Human Science:
    In front of Zeno’s Paradox, our human’s wisdom and science have nothing improving at all?

    This question has been asked for more then 2500 years since Zeno’s time with his paradox. The question never being answered scientifically so the “Infinitude Related Paradox System--------“infinitude defects syndrome group”” develop with numerous family members. The problems disclosed by paradoxes’ family members are relating to the fundamental defects of the theory system and the most difficult problem is the scientificity of the contents of human science: the “scientificity” of infinitude conception? the “scientificity” of infinitude related number forms(such as infinitesimals and variables)? The “scientificity” of treating theories and techniques of the infinitude related number forms(such as limit theory)? The “scientificity” of scientific concepts? The “scientificity” of logics? The “scientificity” of Working train of thought? …. 2500 years passed in a flash, in front of Zeno’s Paradox, our human’s wisdom and science have nothing improving at all!The problems have being there challenging we human being for more then 2500 years, we should not run away not matter how difficult and how hard they are---------human science is human’s.
    We should integrate the problems disclosed by all kinds of infinitude paradoxes and pay much attention on the very fundamental research.


    In front of Zeno’s Paradox, our human’s wisdom and science have nothing improving at all?

  • Ardalan Armin added an answer in Image Sensors:
    Does anybody know any paper regarding modeling of charge carriers and/or exciton transport in image sensors?

    Does anybody know any paper regarding modeling of charge carriers and/or exciton transport in image sensors? The physics therein is very similar to the solar cells but there are some specifics. I'm looking for the literature concerning the image sensors spesially.

    Ardalan Armin · University of Queensland

    Hi MVB,

    The difference between photodiodes (with very similar physics to solar cells) and image sensors is mostly some engineering related. So I would suggest you review the OPDs literature as well as drift-diffusion modellings previously done for OPVs.

    Some principles about the impact of charge transport properties in organic photodiodes are explained here:

     https://www.researchgate.net/publication/264428141_Thick_junction_broadband_organic_photodiodes?ev=prf_pub

    With best wishes

  • Zwi Barnea added an answer in Crystallization:
    What methods can I use to check the shape of crystals?

    Dear All

    I have analyzed the quasicrystal i have prepared by xrd, but i'm not sure if the crystallization is correct. I know that we can check it via TEM or another method. May I ask about the other method which we can check the shape of the crystal?

    BR

    Zwi Barnea · University of Melbourne

    Also, sometimes you can recognize crystallographic directions from the symmetry of a developed surface (set of planes).

  • Chandra Sekhar Singh asked a question in Fuzzy:
    Can any one help me regarding Fuzzy AHP, FUZZY ANP and FUZZY TOPSIS methodology?

    I am working on Intellectual capital (IC), Organizational learning and HRD practices in India. I am looking to establish a relationship between IC and Organisational learning.

  • David L Morgan added an answer in Design Research:
    What is the difference between embedded and nested design in researches?

    Is embedded mixed method differ from nested design?

    David L Morgan · Portland State University

    Part of the reason Nolundi and others are confused by this terminology is that these terms largely come from lists, especially those compiled by John Creswell, where the items are not necessarily mutually exclusive.

    For example, as I said earlier, nearly all "embedded" designs are actually of the form QUANT --> qual where the QUANT is dominant and the qual is used as a follow up.

    In Creswell's terms, this would be "sequential explanatory" design (where the origin of that label is from an article by Jennifer Greene et al., 1989). So, in practice, most embedded designs are also explanatory sequential designs.

    My advice would be to begin by deciding which method is your primary one. That means determining what your overall goals are and thus which kinds of methods have the core strengths that you need to meet those goals. After that, you should choose a supplementary method that makes an important contribution to your method.

  • What is the maximum tolerable humidity and oxygen level inside the glove box while annealing the P3HT:PCBM based solar cell?
    Do we really need to measure the relative humidity and oxygen level inside the glove box while annealing the sample of OSC(P3HT:PCBM)? Or is it ok just to measure the inert gas pressure inside the glove box using the pressure gauge and maintain a slight positive pressure inside the chamber? Your suggestion will be highly appreciated.
    Ardalan Armin · University of Queensland

    Dear Ravi,

    Difficult question to answer. The level of oxygen and perhaps humidity when annealing defines the doping level these devices achieve. It has been shown that such doping up to some extent is harmless for device performance as it does not change the mobility and recombination, again, up to some extent. (see https://www.researchgate.net/publication/264378517_Doping-Induced_Screening_of_the_Built-in-Field_in_Organic_Solar_Cells_Effect_on_Charge_Transport_and_Recombination?ev=prf_pub). If doping level goes too high then your devices will suffer from doping induced recombination via screening of the electric field.

    Apart from above discussion, you are definitely safe < 10 ppm and maybe < 100 ppm. If you anneal your devices after electrode deposition (post annealing), they will be less sensitive to air exposure.

    If it is difficult for you to measure and control the oxygen level I suggest you use fabrication protocols not using annealing such as slow drying. For that, you will need to take the film off the spin coater while still wet and let them dry in a closed box in few hours. That increases the degree of crystallinity. This process can be done even in the air.

    Good luck!

  • 10 authors in 1 paper

    When searching for papers in the Web of Science, found it curious to find a paper with 10 authors. Admittedly, i believe that some of these do not know the work, and had his name published only interests. What do you think about this?

  • Larry Carlson added an answer in History:
    History and Miracles: If Miracles are Possible, Could a Historian Conclude that a Miracle Occurred?

    On the belief that miracles are at least possible, is it possible for a historian to demonstrate and conclude that event X was a miracle?

    Larry Carlson · United Tribes Technical College

    Pavlov:
    Of course, there are plenty of scientists in the world who are also Christian and who will tell you that, for example, as a scientist they believe in evolution and the time spans that go with it, but as a Christian they believe, in the name of faith, that the Biblical creationist account, though at odds with current evolutionary theory, is correct. To me this is all a bit of verbal legerdemain, e.g. wanting to have one's cake and eat it too. That is fine, but again, I don't know how these scientists expect to carry on a rational dialogue with their less credulous colleagues..


    For example, it is not widely accepted within any nonreligious academic discipline that the Bible is a reliable source of history. Of course some, but not all, of the information in the Bible has been corroborated to varying degrees by various and sundry anthropological discoveries. But it seems an in-credible leap to conclude that therefore everything in the Bible can be taken literally, including accounts of miracles. Indeed, historians have written that many of the narrative accounts in the Bible are exaggerated, distorted, mythical, or downright spurious (e.g. even the historical existence or whereabouts of King Solomon's temple is a hotly debated topic among historians and archeologists).


    Every so often, for example, one comes across articles that suggest that remnants of Noah’s ark have been found. Are we thence to conclude that this proves that there is a God who miraculously created a deluge, for whatever purpose, which wiped out everything not on an ark? . I think not.


    Someone finds a shroud or chalice or whatever that might be linked to someone with the common name of Jesus who has since been referred to as Christ. Fine. But does that in anyway prove or even provide reasonable evidence that Biblical accounts of the miraculous resurrection of Christ are historical facts? I think not.
    ETC.
    My point is that science typically remains agnostic about everything as long as the “jury” is still out. Though there are a few dissidents, the jury is in with regards to the validity of evolution as far as most scientists and historians (i.e., anthropologists) are concerned. Not so regarding the miracles in the Bible, much less the literal validity of the Bible in general.


    Again, hopping back and forth across the lines of faith and science is fine as long as one keeps to the usual standards of verification set by most historians and scientists when one is claiming that religious/spiritual beliefs, e.g. miracles, are supported by science.

  • Phan Hong added an answer in Mindfulness:
    Feedback from mindfulness training?
    What were issues highlighted carrying out mindfulness training? Could you please describe the countermeasures? Were the countermeasures effective? Any weak points of the countermeasures?
    Phan Hong · University of Wisconsin - Oshkosh

    One of the most difficult things about doing mindfulness research is that there is not measure of state mindfulness, just trait mindfulness, so it difficult to know if your manipulation of mindfulness actually produced an effect.

  • Conservation. Agriculture and weed management

    How to conrol weeds in conservation agriculture without    Using herbicides. In rainfed regions in maize. And pigeonpea

  • Dejenie A. Lakew added an answer in Robotics:
    What are applications of convex sets and the notion of convexity in mathematics and science?

    In a Euclidean space, an object S is convex, provided the line segment connecting each pair of points in S is also within S. Examples of convex objects in the attached image include convex polyhedra and tilings containing convex polygons.  Can other tilings containing convex shapes be found?

    Solid cubes (not hollow cubes or cubes with dents in them) are also examples of convex objects.   However, crescent shapes (a partial circular disk containing all points inside the disk) are non-convex .   To test the non-convexity of a crescent, select a pair of points along the inner edge of a crescent and draw a line segment between the selected points.   Except for the end points, the remaining points in the line segment will not be within the crescent.  Except for the 3rd and 5th cubes, the cubes in the attached images are convex objects (all points bounded by walls of each cube are contained in the cube).

    http://en.wikipedia.org/wiki/Cube

    From left-to-right, the cresent shapes are shown in the attached image are non-convex: Nakhchivan, Azerbaijan dome, Taj Mahal, flags of Algeria, Tunisia, Turkey and Turkmenistan. For more examples of crescent objects, see

    http://en.wikipedia.org/wiki/Crescent

    Can you identify other crescent shapes in art or in architecture that are non-convex?  Going further, can you identify other non-convex objects in art or in architecture?

    The notion of convexity leads to many practical applications such as optimization

    http://www.lix.polytechnique.fr/~liberti/phdthesis.pdf

    image processing

    http://signal.ee.bilkent.edu.tr/Theses/kkoseThesis.pdf

    and antismatroids, useful in discrete event simulation, AI planning, and feasible states of learners:
    http://en.wikipedia.org/wiki/Antimatroid
    In science, convex sets provide a basis solving optimization and duality problems, e.g.,
    http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-253-convex-analysis-and-optimization-spring-2012/Syllabus/MIT6_253S12_summary.pdf
    Convex sets also appear in solving force closure in robotic grasping, e.g.,

    https://www.researchgate.net/publication/221105156_Projection_on_Convex_Set_and_Its_Application_in_Testing_Force_Closure_Properties_of_Robotic_Grasping

    Recent work has been done on decomposing 2D and 3D models into their approximate convex components. See, for example, the attached decompositions from page 6 in
    J.-M. Lien, Approximate convex decomposition and its applications, Ph.D. thesis, Texas A&M University, 2006:

    http://cs.gmu.edu/~jmlien/research/app-cd/lien-dissertation.pdf

    There are many other applications of the notion of convexity in Science. Can you suggest any?

    Dejenie A. Lakew · John Tyler Community College

    Dear James,

    Aside from the convex sets in Euclidean spaces either abstract or geometric used in applications (optimization, control theory, etc) and for the sake of abstract studies that are closed  by segment connectivity, to see that notion of being convex outside of mathematics, any matter that constantly moves, rotates and have frictions with an outside physical matter tends to become convex - as the edges or corners that pointed inward, reasons of concavity,  forced to disappear over time.

    The universe is a convex set in which no dent will exist as it rotates and moves outward constantly.  We also see that things in nature that tend to be stable are either convex or star-shaped as the existence of dents make them loose stability and eventually disappear from existence or from their original position.

  • Zeba Naqvi added an answer in Books:
    Book on microresonators

    I am looking for a book on theory of microresonators, telling everything about their modes families, their origin and all kinds of dispersion esp geometric dispersion. Something like Oraevsky's paper. A book dedicated to only microspheres will also help. Any suggestions? Thanks

    Zeba Naqvi · University of North Carolina at Charlotte

    Thanks Hossein. I have this book. I am looking for theoretical treatment of modes in different geometries explored till now. May be only theses and papers are the source. But given the fact that at least uspheres are pretty old now, there should have been a good book on that. Stratton still is the go to book. wish someone did the job of Stratton in the modern context.

  • Rubén Cereijo added an answer in Adipose Tissue:
    How can I improve hematoxylin/eosine staining of brown adipose tissue?
    We are having trouble staining mouse brown adipose tissue with this method - it is very faint and nuclei are almost unstained.That would be an hematoxylin issue, so we double-checked every possible item which could be an issue. However, the dye is ok (samples from other tissues are perfect), sample thickness is 4 mm, and every step in the dyeing process is performed correctly - as I said, we aren't experiencing any problems with tissues other than adipose. The samples are fixed in a 4% formaldehyde solution and stored in 70% ethanol.
    Rubén Cereijo · University of Barcelona

    Hi Patrick, yes, it worked. In fact we also had success with the older protocol. Apparently, the problem was with the hematoxylin, which wasn't properly prepared after we received it from the provider. With a fresh batch of hematoxylin both protocols worked perfectly.

  • What is your opinion about using FreeMedicalJournals as a source for full-text articles and a systematic review?

    Today during a training for medical residents from the clinical postgraduate courses of the university, the trainer suggest use FreeMedicalJournals as a significant source of full-text articles and a source for a systematic review. Although I strongly disagree I would like to read opinions about it.

    Alfonso J. Rodriguez-Morales · Universidad Tecnológica de Pereira

    Farhad, totally agree with you!

  • Tushar Ray added an answer in Scientific Research:
    Should studies published in ResearchGate and refereed by ResearchGate peer reviewers be counted as scholarly publications?
    Yes, in my humble opinion. Firstly because scientists have an interest in disseminating their intellectual work through an interactive, secure and free medium. Secondly, traditional journals use the same pool of academics as referees to review submitted articles. And thirdly, It allows for post publication peer review.
    Tushar Ray · State University of New York Upstate Medical University

    It should be considered scholarly if the RG publication brings out novel conclusions based on the authors prior publications (see attachment) along the same line of investigation in various reputed journals. I have included a list of experts in the field of ion-pumps, Ca-signaling and allosteric regulation who has been invited to openly discuss the problem so that the truth can come out. Currently, I have an important paper on Cytosolic regulation of Na-pump by a 170 k Da. regulatory protein, in open access F1000 that has been waiting for peer review for nearly a year; though numerous reviewers have been requested but no response so far. The papers, just mentioned (based on solid data), suffered recent rejections from "classic"-publication venues where I published earlier without any problem. 

  • What would you do if you received a report from the reviewer of your paper asking for a major revision, with which you completely disagree?
    What would be your response? Would you appeal to the editor by asking him/her to make the final decision, would you be weak and amend what you believe is right, would you argue back with facts, would you re-submit the paper to another journal?
  • Louis Brassard added an answer in NATO:
    A referendum on full Scotland's independence is in progress. How will the results of this referendum affect the European Union, NATO ...?

    Scotland's independence could bring some reflections to some European regions such as Catalonia, South Tyrol, Flanders, the Basque Country. Even some ideas of ​​new state of Kurdistan can be dangerous, especially for Turkey who would like to become a member of the European Union. What are your concerns about, if any?

    Ljubomir,

    Multiculturalism was one of response of Trudeau to the quebec national problem within Canada.  Lets accept all cultures.  I have mixed feeling about the last 25 years of the Canadian multiculturalist experience.  I live in BC since the last 23 years so in there I am one of the less important minorities of the province.  Vancouver is a very multi-cultural city.  I call the people being born here: the native because they are less than 25% of the population.  Multiculturalism has made French minorities  more accepted everywhere in Canada.  French canadian used to avoid speaking french in public and now that the chineese, the Penjaby, the vietnameese, the koriean, the philippinose can do it then it is OK for us too. I is not longer socially acceptable to call us frogs.  Because of large immigration rate and multiculturalism open racism is almost none existant although the canadian natives (amerindien) are still the less privilege minority in Canada with living condition similar to the third world.  There are a lot of positive to say about multiculturalism in Canada.  There is no major obstacle for new immigrant to find jobs and to have their own school and continue their own tradition.  In spite of all this positive, I have a sad feeling that Canada is loosing his identity and even the strenght to defend some traditional values we have when they are challenge by some minority group.  Now muslim women have win the right to vote with a veil on their face.  Ten years ago in Ontario, the muslim community almost wan the right to have a sharia for family law.  The sick wan the right to wear their traditional costume within the military and the royal police which where English canadian symbols.  In northern BC, there is a community of Mormon fundamentalism that practice exclusion of young male teenager and the marriage up to fifty woment to a single man.  Young girl of 14 get married to man in the sixties with up to fifty women.  The charter of right and the total lack of cultural affirmation in canada make it almost impossible to stop this.

  • Preetpal S. Sidhu asked a question in SNP Genotyping:
    SNP Genotyping Validation Study

    We are trying to initiate SNP DME genotyping in our test panel. Can anyone please guide me through the validation protocol?

  • Sabarish Nagarajan asked a question in mRNA:
    MRNA association with ribosomes

    When I do qRT_PCRs in my polysome fractions of Drosophila larval lysates, I see around 95% of a particular mRNA (eg. actin) associated with 2 or more ribosomes. Why is it ribosome association with 40S subunit or as a part of some mRNP complex, seen only in a very small percentage of the mRNA?

  • Why are tumor suppressor proteins down regulated in cancer cells?

    Why are tumor suppressor proteins down regulated in cancer cells even they are not mutated.

    Can some one explain signaling for this down regulation of tumor suppressor protein with any example or provide literature about this.

    Leonardo Vinícius Monteiro de Assis · University of São Paulo

    The down regulation of TS proteins and genes are crucial for cancer progression. Cancer cells also activate oncogones, which are responsible for sending growth signals, resulting in cell proliferation. 

    In fact, you don't need a mutation to render the gene inactive. You have several ways to silence a gene without having a mutation.  

    Now, how this happens is indeed complex. 

    Basically, you have to think in three ways: 

    DNA level: Epigenetics - DNA polimerase needs a sequence of DNA to start; however, this sequence can be packed (''hidden''), and thus no transcription happens. You have several enzymes that acytelates histones. In some cases, you over expression of gene that is an inhibitor of your target gene. 

    RNA level: Degradation of RNA by Rnai; splicing, RNA processing (poli A tail, CAP);

    Protein level: Phosphorylation, ubiquitination and post translatational modifications that leads to protein degradation. 

    This process is way more complex than I said - for that I recommend the following articles: 

    http://www.ncbi.nlm.nih.gov/pubmed/11932736 

    http://www.hindawi.com/journals/tswj/2014/896206/

    http://www.ncbi.nlm.nih.gov/pubmed/21802130