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  • Mansour Mededjel asked a question in Internet of Things:
    How can we use Internet of things and physical Internet to develop logistics solutions ?

    The problem is to provide a solution to logistics problems using emerging technology such as IoT, IP.

  • Reza Hoseinpour added an answer in Column Chromatography:
    Is it possible to separate an analyte and its salt simultaneously by HPLC?

    I am asking about the possibility of separation of an analyte like pseudophedrine and its salt pseudophedrine hydrochloride using HPLC simultaneously i.e using the same method?

    If it is not possible, any suggestions for determination of the two compounds in one sample?.

    Reza Hoseinpour

    To do this it is best that the electrochemical method is used, the salt remains on the HPLC column.

  • Jarrod G. added an answer in Dentistry:
    How can tartar and plaque be removed from teeth without grinding? is there any paste, etc. for it?
    How can tartar and plaque be removed from teeth without grinding? is there any paste, etc. for it?
    Jarrod G.

    I believe I have the solution to this.

    I have combined two products that are currently on the market, that when taken orally, will remove tar from your teeth. This will eliminate the need to go to the Dentist to have your teeth scraped. The problem is, I need advice where to go next. I need to have the ingredients evaluated to figure out which ones are the cause, and then make a whole new product from A+B, and make it available to consumers. Im kind of lost at this point.

    Can anyone point me in the right direction? - ResearchGate. Available from: https://www.researchgate.net/post/Can_anyone_point_me_in_the_right_direction [accessed Oct 13, 2015].

  • Erik B. Melchiorre asked a question in Mineralogy:
    Alpine Serpentinites: Can You Suggest a good overview article?

    Can anyone suggest a good overview article on what makes Alpine Type serpentinites different from others? I know that plots of Cr# vs Mg# have different fields, but what else is different and why? Mineralogy? Any estimates of P-T conditions, or are they variable?

  • Erin Dobrinen added an answer in Flow Cytometry:
    Did anyone virus titration via flow cytometry?
    I want to titer my adenovirus stock (Ad-GFP) via flow cytometery instead of plaque assay does anybody to do this?
    thanks in advance
    Erin Dobrinen

    It's also been done this without an antibody by measuring the size of the cells.  I don't know which viruses produce a measurable swelling in cells though. 

    Estimation of baculovirus titer based on viable cell size
    Vasantharajan Janakiraman1,3, William F Forrest2,3 & Somasekar Seshagiri1Nature Protocols 1, - 2271 - 2276 (2006)

  • Gregory M Zarus added an answer in Wastewater Treatment Plant:
    What could be the relation between odours units and concentrations of several wastewater compounds? Works for comparing results?

    I am trying to related the odour units with the hydrogen sulphide and ammonia concentrations levels measured with passive sampling.

    I'm publishing emmissions rates (in g/s) of several wastewater treatment plants and I like compare my results with others works!.

    Gregory M Zarus

    I would add, that the averaging time is a key issue between odor detection and chemical measurement.  I was surprised to be able to smell H2S downwind at a concentration < 2 ppb using one instrument with a 5 min averaging time.  I never smelled it in the lab so low.  But when using a method that was nearly instantaneous, I observed that the true downwind value fluctuated to levels above 10 ppb for short times --well within my ability to smell. 

    A report about chemicals found at this site are at:

  • Kathe Akaija added an answer in Anthropology:
    Who would like to cooperate with us in a large-scale cross-populational research project?

    Dear Colleague,
    We would like to invite you to our new, large-scale cross-cultural research project.
    Our previous research projects, conducted in 53 study sites, turned out to be a great success. One of our manuscripts (from a first project) was published in Journal of Cross-Cultural Psychology, other from the new project is currently under review in the same journal, one will soon be submitted to the Journal of Marriage and Family, and three more papers are in the final stages of preparations. Thanks to our efficient team work we now collaborate with, e.g., David Buss.

    It is more or less psychological study, bu we would like to invite to coopaeration scientists from all fields of social or biological sciences.

    This time, we plan to conduct six studies.
    a) Sexual Morality Project
    b) Comparison of daily life touch between countries
    c) Creativity study
    d) Love study
    e) Mate study
    f) Facebook study

    Now, we have collaborators from +- 60 countries (see list below). New collaborators from                                   - O T H E R - countries are WELCOME!

    Algieria, Argentina, Australia, Austria, Belgium, Brazil, Canada, Chile, China, Costa Rica Croatia Cuba Czech Rep Denmark Estonia Etiopia France Georgia Germany Ghana Greece Hong Kong Hugary India Iran Ireland Italy Japan Kenya Korea Latvia Lebanon Lithuania Macedonia Malaysia Malta Mauritius Mexico Nepal Netherlands New Zealand Nigeria Norway Pakistan Peru Philippines Poland Portugal Romania Russia Salvador Slovakia Slovenia
    South Africa Spain Sweden Switzerland Turkey Uganda UK Ukraine Uruguay

    Kathe Akaija

    I would be interested in participating.  I am a single, hetero-sexual, 58 yr old female living in Calif., USA.  Working on my M.S. in Psychology, on-line, and raising my eight year old granddaughter. Feel free to contact me at kathe.akaija@snhu.edu

  • Nrip Kishore Pankaj asked a question in Plant Extracts:
    Can any body suggest the cell lines to be considered for insulinomimetic activity of some crude plant extracts?

    Can any body suggest the cell lines to be considered for insulinomimetic activity of some crude plant extracts as well as estimation of glucose consumption?

  • Jarrod G. asked a question in Teeth:
    Can anyone point me in the right direction?

    I have combined two products that are currently on the market, that when taken orally, will remove tar from your teeth. This will eliminate the need to go to the Dentist to have your teeth scraped. I need to figure out what ingredients are the cause of this, to create one product. A product that I believe needs to be available to consumers. Can anyone point me in the right direction?

  • Shailendhra Karthikeyan asked a question in Pulsatile Flow:
    Is there anyone who has worked on pulsatile flow through tube of elliptic cross section and hanled the complexity of Mathieu functions? ylinder

    .  I am working on pulsatile flow of blood in an artery with slightly elliptic cross section and landed up with Mathieu Functions.  The computational complexity of dealing with continued fractions and recurrence relations poses a great threat.  There are some classical work on these lines way back in 1950's but due to poor computational facility at that time, the authors have just provided mathematical solutions without carrying out any computational work to understand the flow characteristics.  Any comments on this? References?

  • Ademola Adekunle asked a question in Microbial Electrolysis Cell:
    Software for 3D schematics of Microbial Fuel Cells or Microbial Electrolysis Cells?

    I have seen some very nice 3D schematics of electrochemical systems representing microbial fuel cells...does anyone know in particular what software does this best? I am trying to make a custom one for my research...any pointers will be appreciated.

  • Bikash Sharma added an answer in Green IT:
    Is green economy really old wine in green bottles or a new paradigm?

    In recent years, the concept of green economy is increasingly used as pathway to sustainable development (SD).  Also the concept of inclusive green growth is now commonly used similar to the concept of green economy. Since both these concepts are rooted in the same three pillars/dimensions of SD (social, economic and environmental), it makes little sense for me to differentiate these concepts as new paradigm from the very notion of SD, perhaps coined/driven by the failure of actual implementation of SD since its inception in 1987 (Brundtland report) despite rhetoric on its conceptualization. What do you think?  

    Bikash Sharma

    Dear Bachir and Lucio,

    Most respectfully I very much appreciate your explanations of the why and how of green economy with supporting materials. Thank you very much. 

    Yet the pertinent question I raised is not about its concept and principle as an alternative strategy but whether this vision might achieve sustainable development or fall again into the trap of placing economic growth paradigm.

    The discourse of unavoidable technological progress will severely limit our capacity to conceive of solutions outside of the economic sphere. Further  the weak sustainability approach advocated by UNEP green economy becomes redundant if we cannot substitute natural capital with physical capital. And strong sustainability approach will requires another paradigm shift in thinking globally and acting locally.  

    As Albert Einstein rightly said, “the significant problems we face cannot be solved at the same level of thinking we were at when we created them”.

    It is therefore yet to be seen how this green economy vision including those enshrined in the post 15 + SDGs agenda will withstand the test of time.  If not, who knows another alternative paradigm say bio- economy  may emerge to achieve the very goal of SD !

    These are just my stray thoughts seeking your further insights and reactions if any.

    Best regards,


  • Arikkath Mana Kunhan Namboodiri Vasudevan added an answer in Soil:
    What will be the immediate solution to strengthen foundation when sinkhole occurs below it? How can prevent further advancement of sinkhole?

    The unconsolidated soil when becomes fully saturated by rainwater and carried away underground, the soil gently slumps or erodes into the developing underground large voids (sinkhole). It is further extended below the footing of building which is located at the top of slope. In this context, what will be the appropriate cost-effective action to strengthen foundation and what materials/techniques would be useful to fill holes and stabilize foundation soil?

    Arikkath Mana Kunhan Namboodiri Vasudevan

    Grouting is the best method to fill the holes, and which will also prevent further  advancement of  sink holes.

  • Anouk A J Hamers added an answer in mTOR:
    How to make sure rapamycin completely dissolve in medium?

    Hi, all,

    I prepared the rapamycin in DMSO (5mg in 5 mL, that is roughly 1 mM), then aliquot to 100 ul, I diluted it in serum free DMEM before use (10-fold serial dilution), then treated the cells 1h/6h. But neither my target protein nor mTOR phosphorylation is affected. The concentration I used are 20nM, 50nM, 100nM, 200nM.

    There is not possible I did the cells harvest or WB wrong I have other treatments along with it. So I thought something is wrong with the preparation of rapa. Someone said I should let the rapamycin dissolve more completely by putting it at a shaker for hours, covering with foil paper. What I did just vortex several time and make sure it is clear in DMSO then aliquot directly. 

    Someone said I should warm up to 37C (both of DMEM and rapa solution) when I did the serial dilution. What I did just add 900ul DMEM (right out from refrigerator) and pipette to ensure it is aqueous. I DIDNOT notice any precipitation. Not I did not see it but I didnot notice it will be a problem back then.

    I repeated the experiment 4 times but it is just numerical difference,  now I am running out of clues. If you have any suggestions I will be really appreciated!

    Thanks for your help in advance!

    Anouk A J Hamers

    Hi Liang,

    That sound like a really good plan ;-)

    Good luck and let me know if it works!

  • Sherif Moussa added an answer in Metal Oxides:
    In which case the TEM and XRD can not identify supported metal or metal oxides?

    I have prepared Manganese oxides insitu grown during the synthesis of silica nano spheres with fibrous morphology by one step hydrothermal process. MnOxides concentration shown by XPS is 0.13% while by ICP-AES is 1.1%. EDS also give the peak. XRD only gives the standard peak for Silica at 22 but there is no peak of Mn-Oxides. If compare the pure Silica TEM with Mn oxides incoporated Silica, there is only a little distortion in the samples but no Mn oxides can be observed. so i believe that Mnoxides may be well dispersed or embedded or  without any aggregation to be visible by TEM or detected by XRD. Please anyone can comment that TEM and XRD results are mutually consistent or not?

    Sherif Moussa

    Your MnOx contents is below the XRD-detection limit, and most likely will not show up on the TEM either. You need HRTEM as other researchers suggested. Also, you need to increase your MnOx contents to accurately identify the phase present and morphology.

  • Reena Singhal added an answer in Hydrogel:
    What is the maximum swelling ratios obtained from new generation cellulosic based hydrogels?ref. if possble.

    cellulosic hydrogels for agriculture: What is the maximum swelling ratios obtained from new generation cellulosic based hydrogels?ref. if possble.

    Reena Singhal

    Thanks PAM is not biodegradable ,while cellulose based hydrogels can be biodegradable.

  • Tessa Abigail van Walsum added an answer in Behavioral Experiment:
    How should we train a bird (pigeon, crow, chicken, ...) to do a same or different visual task?

    We want to train some kind of birds to recognize similar object in a match/non-match behavioral experiment. We have no previous experience in animal experiments. Our main question is about the existing methods to train these animals to do the desired task.  

    Tessa Abigail van Walsum

    Dear Saeed,

    I'm not entirely sure what you would like to do, but I remember reading literature on homing pigeons and how they learned a specific route - which then varied with other individuals. In this case the study relied on the pigeons themselves to 'teach' each other. Maybe this is of interest to you?

    Best wishes,


    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: Travelling in groups gives animals opportunities to share route information by following cues from each other's movement. The outcome of group navigation will depend on how individuals respond to each other within a flock, school, swarm or herd. Despite the abundance of modelling studies, only recently have researchers developed techniques to determine the interaction rules among real animals. Here, we use high-resolution GPS (global positioning system) tracking to study these interactions in pairs of pigeons flying home from a familiar site. Momentary changes in velocity indicate alignment with the neighbour's direction, as well as attraction or avoidance depending on distance. Responses were stronger when the neighbour was in front. From the flocking behaviour, we develop a model to predict features of group navigation. Specifically, we show that the interactions between pigeons stabilize a side-by-side configuration, promoting bidirectional information transfer and reducing the risk of separation. However, if one bird gets in front it will lead directional choices. Our model further predicts, and observations confirm, that a faster bird (as measured from solo flights) will fly slightly in front and thus dominate the choice of homing route. Our results explain how group decisions emerge from individual differences in homing flight behaviour.
      Journal of The Royal Society Interface 09/2013; 10(89):20130529. DOI:10.1098/rsif.2013.0529
  • Abdul-Kadri Yahaya asked a question in Descriptive Statistics:
    How useful is descriptive statistics?

    Data Analysis in instrumental in research. Descriptive statistics is used in the analysis of quantitative data.

  • David Thornton added an answer in Gravitation:
    In GR, can we always choose the local speed of light to be everywhere smaller that the coordinate speed of light? Can this be used in a theory?

    It seems that many, if not all, solutions of Einstein's equations, such as black holes and grav. waves, can be given coordinates x\mu in such a way that the local speed of light is always slower than the coordinate speed of light. Think of gravitational lensing: the index of refraction of a gravitational potential always seems to be >1, in practical examples, so a gravitational potential slows light down, and never speeds it up (if coordinates are chosen carefully). This wouldn't be true for a negative-mass Schwarzschild solution, but that seems to be outlawed in nature.

     Now this was only a conjecture, I have not attempted to prove it. How would a rigorous mathematical theorem be formulated? And did anybody - and here I mean a wise person, not the average blogger - ever try to do something interesting with this observation? Like constructing a “hidden medium” for curved space-time?

    David Thornton

    Thierry De Mees, surely Gravitomagnetism is only the GR Field Equations in the weak-field, low-velocity limit......?

  • Shailendhra Karthikeyan added an answer in Fluid Flow:
    What are physical applications of MHD Maxwell fluid in circular cylinder or pipes?

    I want to know real life or Industrial application of Maxwell fluid and its flow in cylinderical domain.

    Shailendhra Karthikeyan

    Many authors just convert every Ordinary Fluid Dynamics Problem into a corresponding MHD problem by just adding the Lorentz force in the momentum equation and using appropriate electromagnetic (Maxwell's equation).  When this method is followed, you are solving a MHD and trying to fix an application.  I think this is not a right method.  Choose a practical problem which demands MHD equations and try to find a method to solve.  Estimate the parameter like Hartmann number and check if Lorentz force is sufficient enough to modify the flow.  Good luck. 

  • Rudolph E. Schild added an answer in Foundations of Physics:
    Do you agree with Stephen Hawking's recent conclusion that black holes don't exist?
    Black holes don't exist. I published this many years ago. Cantor's Universe doesn't allow the concept.

    Stephen Hawking now came up with the same conclusion. Read: http://www.spektrum.de/news/es-gibt-keine-schwarzen-loecher/1222059

    In my opinion he is right this time. What is your opinion? Was he right then or is he correct now?
    Rudolph E. Schild

    Please permit me to support the realization by Kali Charan that Prof Abhas Mitra of India has made the breakthrough discovery that the Hawking black hole with infinitely dense event horizon does not exist in nature. This discovery was actually the discovery that an Eternally Collapsing Object (ECO) is a correct solution to the Einstein-Maxwell equations that has instead a surface of extremely large but finite density. As was later demonstrated by Darryl Leiter and Stanley Robertson, this solves two major problems in black hole theory. The first is the problem of the unitarity of wave functions, where quantum wave functions are cut off at the event horizon if it has infinite density. A long controversey by Leonard Susskind and Steven Hawking is completely sidestepped if the objects do not have infinite density surfaces.

    The second problem is that the Einstein GR theory requires that all physical processes must join space in a general relativistic time-like coordinate transformation, and there is no possible such transformation connecting the space between the inside and outside of the Hawking black hole. This is sometimes called the Strong Principle of Equivalence. These assertions are treated mathematically in the appendicies of the paper by Schild, Leiter, and Robertson (2006) AJ, v132 p420 = astro/ph:0505518

    Taking off from where Indian Physicist Abhas Mitra left off, Darryl Leiter showed that from relativistic quantum electrodynamics pair creation would cause spontaneous pair production at a tremendous rate that stops the infall, and they go on to discover the equation of state for the black hole structure, which is now called a MECO. Steven Hawking conceded that there could be such a "meta-stable quantum state" but forgot to give credit to the people who discovered it, possibly because it is a somewhat complex story. It took a complex team of experts in GR, relativistic quantum electrodynamics, and relativistic E-M theory. Understand thatSteven Hawking made a profound concession that all of his life's work, based upon the old black hole paradigm, may be wrong, including his theory of black hole evaporation.

    I recommend that Kali Charan study with Abhas Mitra immediately.

  • George Stoica added an answer in Arts Research:
    Which theatre practitioners or performance artists use archival material in their work?

    I am loking for artists who incorporate visual arts research into their theatre-making process. I am interested in the relationship between the document and the artist: What is it they are looking for? How do they approach these materials - as artefacts, as stimuli, as traces, as collaborators? I have a good understanding of the theoretical background to this debate and of the various innovations in performance documentation, but I want to learn about the ways archival material circulates in professional theatre as active tools.

    George Stoica

    Erick von Stroheim was a perfectionist as a director as well as an actor. Remember him in Sunset Boulevard...

  • Arikkath Mana Kunhan Namboodiri Vasudevan added an answer in Soil Quality:
    What are the three most important soil properties (physical, chemical, biological) that can be used to construct a 'Soil quality/health indicator'?

    Soil Scientists

    Arikkath Mana Kunhan Namboodiri Vasudevan

    It is not clear from the question, the objective of  knowing/understanding the soil properties.

    If the soil is using as a foundation material (as the main application from the Engineering point of view) Strength, Compressibility , Permeability, Resistance against liquefacton are Stiffness are the main properties to be considered.The physical properties(particle size, gradation, void ratio, Atterberg's limits,density etc) will give indication about the Engineering properties. Similarly when the soil is used as a construction material for making bricks, compressive strength is of main concern. Further when the soil is used for the construction of Embankments for highways, Railways, then shear strength is needed. Hence soil quality /health indicator should address these properties depending on the type of application.

    On the other hand, if the soil is using for agricultural purposes, then chemical,physical and biological properties are necessary to know. .However Atterberg's limits ,porosity, density, moisture content etc are also required to be considered which are also index properties in these cases.Fertility is the main concern in such cases and the soil quality/health indicator should address these properties.

  • Anouk A J Hamers added an answer in Endothelial Cells:
    Why do endothelial cells fall off coverslips upon PBS wash?

    Dear All,

    I am growing my endothelial cells on 1% collagen coated glass coverslips. I noticed that occasionally some of the cells fall off and no longer retain their normal morphology straight after I wash the coverslips with non-sterile PBS. I've also tried with sterile PBS but there isn't much difference.

    Will really appreciate any answers.


    Anouk A J Hamers

    Hi Tommy,

    I have experienced the same problems in the past and am now washing with warm medium (no additives). And this seems to work quite well. i think it has to do with the salt concentrations in the PBS. You can perhaps try a milder method by using warm HBSS.

    Also endothelial cells tend to adhere more to a fibronectin coating than to collagen.


  • Subramanian Jeevanantham asked a question in Automobile:
    Engine efficiency monitoring using exhausted smoke ? please tell me possible method ?

    using co2 sensor we can able to measure output of exhaust gas of automobile : how it combustion occur in engine whether it is fully or 80%. depends on that we have to find problem of automobile. please help develop a paper.   

  • Sofia D. Wechsler added an answer in Quantum Mechanics:
    How much time does an electron need for impressing a photographic plate? Does this datum speak in favor of full/empty waves?

    Consider the following experiment: a source of slow electrons emits in the direction z wave-packets with a group velocity 1000Km/s. The wave-packets are of Gaussian form in all three dimensions, with 0.1cm width. We pass the beam through a beam-splitter with such a small transmission coefficient that there remains on average 1 electron per wave-packet. The transmitted part of the wave-packets illuminates a photographic plate.

    From these data there results that the wavelength of the electrons is of the order of 10-7cm=10Å, and that a wave-packet crosses the photographic plate in 10-9s.

    The question is: how much time is needed for an electron of such a velocity to destroy a molecule of the photographic plate? Probably much less by orders of magnitude. Then, could it be that this fact tells us that the wave-packet is mostly ineffective (empty wave) and only a small part inside it (full wave) impresses the plate?

    Sofia D. Wechsler


    the concept of full/empty waves is discussed for a long time, and it is basic in the de Broglie - Bohm mechanics. An empty wave, in the de Broglie-Bohm mechanics, passes through fields, beam-splitters, is deflected, etc., according to the properties of the particle, however, does not impress a detector. A full wave behaves in the same way, but impresses a detector.

    So, please first of all get familiar with these things.

    Also, you ask,

    "But you are no more concerned by the spatial characteristics of the original bunch of electrons"

    READ my question, I said that the wave-packet is Gaussian. As to your question

    "Are you deceived by the cross section of your photographic emulsion ?"

    my question is about full/empty waves, not about deceptions.

  • Nrip Kishore Pankaj asked a question in Plant Extracts:
    Can any body suggest the cell lines to be considered to study insulinomimetic activity of a plant's crude extract ?

    I want to see the insulin secreting action of the crude plants extract over cell line as well as consumption of glucose by the cell lines.

  • Ahmed Ebid added an answer in Piles:
    Is there a relation between experimental results in compression, tension, and lateral loads on screw disk micro piles in cohesive soil from SAP2000 ?

    is there a relation between experimental results in compression, tension, and lateral loads on screw disk micro piles in cohesive soil and theoretical results found from SAP2000 or any theoretical program.

    Ahmed Ebid

    Dear Ahmed,

    I hope the attached book will help

    best regards

  • Kapil Khadka asked a question in Conservation Genetics:
    Is inbreeding the result of reduced population size or is the cause ?

    In conservation genetics, small population size and inbreeding are often the terminology we come across. I am kind of interested to know a better explanation and relationship of inbreeding and small population.

  • Nae Esh asked a question in Introduction: