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  • Denis Efimov added an answer in Metacommunities:
    What software can be used to study the structure of a metacommunity?

    Dear colleagues, prompt software for calculation of parameters a metacommunity. It is desirable to be able to use tables Excel. How can I adequately describe the effect of spatial scale on the part of the community?

    Пакет R активно развивается и отличается от обычного софта тем, что работа ведется в консоле и все операции задаются командами. Немного не привычно, но привыкаешь быстро. В этом его главное преимущество, поскольку можно создавать и подключать модули для выполнения самых разных задач незаморачиваясь при этом с внешним интерфейсом и совместимостью форматов. Кстати он хорошо интегрирован для работы с пространственными данными, например среды ГИС.

  • How can use candoluminescence spectroscopy as flame trace element ?

    Candoluminescece is aflame technique for determination of trace elements  using hydrogen flame .It  has been used for trace nano and picogram amounts of cerium ,euoropium ,manganes ,prasidymium ,bismuth ,lead and antimony .But  now days research has been stopped ,despite the need for trace element  analysis .I encourage researchers to use such powerful tool ,as its not  expensive as ICP  and other tools .

  • Someone will have some reference (article, book) with the recommended daily intake of antioxidants (polyphenols) ?

    I know it's complicated topic, and there are many contradictions about it, but some reference value should exist...

    would appreciate your help.

    Bernhard Biersack · University of Bayreuth


    up to 8 g of curcumin (N. Dhillon et al., Clin Cancer Res 2008, 14, 4491) and 1.6 g of EGCG (U. Ullmann et al., J Int Med Res 2003, 31, 88) are safe and well tolerated.



  • Why is anaerobic digestion not used for low strength wastewater?

    anaerobic treatment is usually done for high strength wastewater but not low strength wastewater. Why?

    Christopher Andrew Buckley · University of KwaZulu-Natal

    The energy yield (for the microorganism) during anaerobic metabolism is much lower than during aerobic metabolism. This results in lower specific growth rates.

    If a continuous completely mixed reactor is used, (hydraulic residence time = solids retention time) then the flowrate of the  substrate needs to be low inorder to prevent wash-out of the microorganisms.

    However if the solids retention time is independent of the hydraulic residence time (i.e. membrane process, an anaerobic baffled reactor, a pelletisation or attached growth system) an anaerobic process can be used with dilute feed solutions.

  • Tarik Nasser added an answer in Ions:
    How do we identify ion types in a mixed solution by potentiometric method?

    I'm using 2 or 3 electrode setup for detecting pH and conductivity changes in potentiometric principle.

    Sensor is good enough to detect low amount of adding ions like salt, glucose,uric acid and many more in single phase.In a case, I add them separately. But the issue is when I add a combination of few ions to the main solution (lets say pH or PBS), the sensor response will change without knowing the particular contribution of each ion on sensor response.

    Is there any way to identify each single ion role on sensor response in a mixed solution? In another word, If I have a combination of ions as one solution, how can I list down the existing ions inside the solution?  

    Best regards,

    Tarik Nasser · Wasit University

    Its possible to  use differential  titration  using platinium electrode and reference electrode ,then by drawing  the curve you see two  inflection points ,using two  electrode  you can get  two  inflection points , using  ion chromatography is useful two  or using differential potentiometry

  • Anil Shankhwar added an answer in Himalaya:
    What is the best way?

    Field inventory method for above ground biomass calculation for Uttarakhand Himalaya?

    Anil Shankhwar · GB Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India

    The desire of non-destructive means of calculating the above ground biomass switches over to application of allometric equations. In this regard species and geographic location specific derived equations may be utilized or it may generated further through regression.   

  • Gul Nabi Khan asked a question in Citrus:
    What is the best technique to understand the embryony (Mono or poly) at the young seedling stage of citrus?

    it is easy to understand the embryony at fruit bearing stage of citrus plant but it is very important to know at young stage. 

  • M. BENDOUMIA asked a question in Powder Metallurgy:
    I need this article, is there anyone who can help me?

    Jangg, G., Šlesár, M., Besterci, M., Ďurišin, J. and Schröder, K. Influence of heat treatment during manufacturing of Al-Al4C3 materials on microstructure and properties. Powder Metallurgy Int., 1989, 5, 25–30

    thank you

  • Ankur Das Barma added an answer in Steroids:
    Which reagent use for steroid test in TLC?

    Liebermann Burchard reagent is used for steroid in TLC,but now acetic anhydride is band, so which reagent will use for steroid isolation in TLC ?

    Ankur Das Barma · Sikkim University

    Thank you Saikat Sir and Aldallal Sir.

  • Charles Francis added an answer in Galileo:
    When and by whom the Relativity Principle was first stated?

    By looking at the original publications, rather than only at the articles and books talking of them, one finds

    Galileo Galilei (1564-1642).
    Dialogo sopra i due massimi sistemi del mondo, Tolemaico e Copernicano (1632)
    Galilei states the relativity principle, without using the term, as a consequence of the experimental evidence, by stating that all possible experiments, with bodies interacting in any possible ways, performed inside a ship cannot show whether the ship is moving or not, provided the motion is uniform. The principle is stated to be valid for all the phenomena.
    After having performed a number of experiments inside a ship standing in the harbour,
    “... have the ship moving with whatever velocity, then (provided that the motion be uniform and not fluctuating in one or the other direction) you will not recognise any variation in any of the just mentioned effects, neither you will be able to recognise from any of them whether the ship is moving or standing.”

    Jules Henri Poincaré (1854-1912)
    L’état actuel et l’avenir de la Physique Mathématique (1904)
    For the first time the term “Relativity Principle” is introduced and stated, on the basis of all the experiments performed at the time, including Michelson Morley, as
    “According to the “Relativity Principle” the laws of the physical phenomena must be the same for a standing observer and for one in uniform translation motion; so that we have no means, neither we can have any, to chose whether we are or not transported in such a motion”

    Albert Einstein (1879-1955)
    Ist die Trägheit eines Körpers von seinen Energiehalt abhänging?, Ann. d. Phys, 18 (1905), 639
    Principle of Relativity: “The laws by which the states of physical systems undergo change are not affected, whether these changes of state be referred to the one or the other of two systems of co-ordinates in uniform translatory motion.”

    Hendrik Antoon Lorentz (1853-1928)
    Deux mémoires de Henri Poincaré dans la physique mathématique, Acta mathematica 38 (1921), 293-308 (written in 1914)
    “It was not me to establish the Relativity Principle as rigorously and universally valid. Poincaré on the contrary obtained the perfect invariance of the electrodynamic equations and formulated the “Relativity Principle”, a term that was first to use.”

    Does anybody understand why usually only the last one, Einstein, is quoted, and the other forgotten?

    Charles Francis · Jesus College, Cambridge

    Johan, see what I mean, Johan, you just cannot read answers. I already told you, on this very page, Einstein already answered Dingle's question 40 years before he asked it, and every real physicist since has answered it, since only an idiot or an incompetent would fail to answer it and still profess to be a physicist. Let's face it, you don't have to be very bright to understand special relativity, you just have to be very dim to criticise something you don't understand.

  • Hussin Jose Hejase added an answer in Workforce:
    Exchanging educational data: Are there any (emerging) international standards?

    Problem: More and more countries are getting involved in the globalized world, partly by strengthening such transnational communities as the European Union and the AEC (ASEAN Economic Comunity). The free movement of the workforce and of students is a fact in this regard. Besides the need for comparable transcripts there is also the need for the secure exchange of such data between national authorities. 

    What are current activities in setting up data international exchange standards (such as EDIFACT (Electronic Data Interchange For Administration, Commerce and Transport, United Nations) for educational institutions?

    Hussin Jose Hejase · American University of Science and Technology Lebanon

    Hi Michael, interesting question. However, I have no knowledge of such a project or activity. Currently, the only interchange I know about is the required public disclosure documents required for American Accreditation like AACSB and IACBE. Here, academic institutions are reflecting on their institutions improvement of outcome assessments of student learning across the different geographic locations around the world (that is, whichever, institution is undergoing the exercise).

  • Neila Ramdhani added an answer in Capacity Building:
    Any suggestions on theories appropriate fo rbuilding teachers capacity?

    Can these theories (Theory of needs, social change theory) be used to study relationship between teachers' capacity building and academic performance of students in the school system?building. Please kindly provide additional theories if you consider it appropriate. Thanks. looking forward to your quick and positive response in appropriation.

    Neila Ramdhani · Gadjah Mada University

    I did a training for improving their capacity in creating a friendly environment. I applied Reinforcement Affect Model's Clore and Byrne. You may read this article http://www.sciencedirect.com/science/article/pii/S1877042812056017

  • Bernhard Wessling added an answer in Polyaniline:
    How I can make best composite of CNT and Polyaniline in pellet form?

    please suggest me the best way

    Bernhard Wessling · BWSI, LaoWei Technology Consulting Inc.

    please do some work on your own, ok? you can enter my RG web site from here, go to my publicatios, and download whatever you think can help. In addition, you can look for my patents via google (scholar.google)

  • Chao Shen asked a question in Stress Analysis:
    In what case can the 3D stress analysis case be treated as the 2D case?

    In what case can the 3D stress analysis case be treated as the 2D case? Take the laser ablation as an example.  

  • What will be the value of active power if RL series branch is used in simulation of inverter connected to grid?

    I simulated z source inverter and connected RL series branch as load with R=10ohm and L= 5mH .Output voltage is 100 and current is 5.I am getting output active power value around 170. But what must be the actual calculated value?

    Djameleddine Bougrine · Université Amar Telidji Laghouat

    The active power is also function of the pulsation w, it is equal to I*V*cos(phi), where phi = atan(Lw/R),  I and V are respectively the RMS values of i(t) and v(t). In your case, if Vrms = 100 V, Irms = 5 A,  and let's consider w = 2*pi*50 then Pa = 5*100*cos(0.1558) = 493 W ..

  • Gyan Chandra Chauthwani asked a question in Software:
    Whether JANIS-4.0 gives the estimation of self shielded cross sections? If yes, how self shielding is taken care in this code?

    JANIS is a Java based nuclear information software, In the user manual it is given that this software takes care for self shielding factor if we give the reactor spectrum in xy format, my question is how JANIS is taking care for self shielding factor?

    Is there any document which describes the process of self shielding in JANIS?

  • Bin Jiang added an answer in Mathematics:
    Is the beauty of patterns or are the structures in patterns the most important source of mathematics?
    It was observed in an earlier thread that G.H. Hardy made the following
    observation in his 194o book A Mathematician's Apology:

    "The mathematician's patterns, like the painter's or the poet's, must be beautiful, the ideas, like the colors or the words, must fit together in a harmonious way. Beauty is the first test; there is no permanent place in the world for ugly mathematics...It may be very hard to define mathematical beauty, but that is just as true of beauty of any kind-we may not know quite what we mean by a beautiful poem, but that does not prevent us from recognizing one when we read it."

    The main issue for this thread is whether beauty or structure comes first in doing mathematics. In terms of structure, consider

    A mathematical structure is a set (or sometimes several sets) with various associated mathematical objects such as subsets, sets of subsets, operations and relations, all of which must satisfy various requirements (axioms). The collection of associated mathematical objects is called the structure and the set is called the underlying set. http://www.abstractmath.org/MM/MMMathStructure.htm

    For example, a set endowed with a proximity (nearness) relation acquires a structure, namely, collections of near sets (each collections contains all sets that are near a given set in a proximity space). Any set endowed with a relation has a structure. Then the question here is Do we first look for structures when we do mathematics?

    The question here is not whether mathematics is beautiful but rather whether beautiful patterns are the starting point of mathematics. For example, is it the painting Mona Lisa or the golden ratios in the painting that first attracts us? See the attached image.
    Bin Jiang · Högskolan i Gävle

    Very interesting thread! I believe it is the new kind of beauty, defined and discovered by Christopher Alexander in his master work The Nature of Order. Objective beauty lies in the deep structure rather than on the surface. I have two papers related to the objective beauty:



    The second paper defined a mathematical model to measure or quantify this beauty.

  • To what extent did the community at large benefit from the extensive number of scientific publications?

    There is a great pool of publications in all areas we can think about. However, one may wonder about the benefits that the community at large (the society) is getting from these. Should there be public lectures offered to raise awareness by the researchers themselves?

    Hussin Jose Hejase · American University of Science and Technology Lebanon

    Actually Cara, I have not published such an article yet, however, work is in progress. At this stage only sharing excerpts.

    Thank you for your interest.

  • What solvent (and concentration) to solve volatile oil in water (without affecting germination and plant growth)?

    Hello everyone. I am trying to solve a volatile oil in water so the question is what is the best way to solve an essential oil in water? Which solvent (DMSO,Tween 20 or 80) should I use and what concentration of it (without affecting plant germination and growth). I used 0,1% Tween 80 and I get and emulsion of the oil, so that's not good. Thanks!

    Hi Ana

    Please see attached literature, might be useful.
    Best regards

  • Mohammed F. Alsayari asked a question in Equality:
    How much does mV equal in joules?

    the energy unit of mV is equivalent to how much jouls?

  • Go J Yoshida added an answer in Insulin Signaling:
    What is the significance of serum starvation when studying molecular signalling pathways especially Insulin signalling?

    why do researchers serum starve the cells before studying the molecular event in a cell line. I am planning to look at the Insulin signalling events in skeletal muscle cell lines, should I serum starve them before stimulation with insulin?

    Go J Yoshida · Tokyo Medical and Dental University

    Serum contains numerous kinds of growth factors and cytokines which contribute to the activation of the signal pathways related to survival and proliferation of the cells of interest. For instance, if you would try to investigate into the susceptibility to EGFR activation between the different types of cells or the cells under the different conditions (e.g. hypoxia v.s. normoxia), you have to use serum-free medium and EGF-containing serum-free medium. After all, serum contains several factors to influence on EGFR signal pathway other than EGF ligand, and further, you have to note that signal pathway is always cross-talked with other signal pathways by negative feedback or compensatory activation machinery (e.g. sustained EGFR activation down-regulates the expression level of EGFR itself, while it can also activate mTOR signaling).

    That is why you have to perform serum starvation before adding insulin, otherwise you cannot obtain the exact data on the time/ concentration-dependent insulin/ IGF-1-mTOR signal activation. How long you have to put the skeletal muscle cell lines under serum starvation before adding insulin to serum-free medium, and how much concentration or how long you have to treat them with insulin, largely depends on the cell context, so that you have to perform trial and error-like experiments.     

  • How can I use/link the MATLAB optimization toolbox for my optimization problem?

    I have an optimization problem for which I need to use Matlab Optimization toolbox but I do not have sufficient idea about the toolbox. I have searched internet but still could not figure out how to link my problem to the optimization toolbox. Can anyone who has utilized the toolbox for some optimization problem tell me the procedure?

    Surya Prakash · Malaviya National Institute of Technology Jaipur

    Just try to solve a small problem with GA or other method using optimization tool box , You can find number of videos on using GA in Matlab on you tube. 

  • How does an Upward OPK affect the brain?

    What about an Upward OPK might react to this with inspiration helping them get better oxygen flow?

    Vladimir A. Kulchitsky · National Academy of Sciences of Belarus

    There are still several questions with OPK. Please, have a look some papers.

  • Can ethanol is used in the Methanol extract of medicinal plant for further analysis ?

    I have prepared, the plant extract in Methanol, but now i want put Ethanol in the residue. Will it Interrupt the experiment ?

    I understand , you have used methanol as solvent for extraction. In this respect the nature of methanol and ethanol are, for all practical purposes, similar. Boiling points of these solvents are, however, different. Please do note that ethanol is a much safer solvent compared to methanol.    

  • What is the relation between stability and tg value for polymeric composite?

    If the polymeric composite is stable than the parent compound then what will be the tg values  either it increase or decrease 

  • Please provide me a way to reconstruct the image of the object from its digital hologram captured in In line digital holography?

    Image reconstruction from hologram

    Michael Zuerch · Friedrich-Schiller-University Jena

    Hello Iftak,

    an overview and details on the numerical reconstruction can be found in the attached link. Also refer to cited references. Some of them are the standard references for digital inline holography in general and are a good read to start with.

    Please note that this is only one of many ways how to implement a DIH reconstruction.

    If you have trouble with implementing it into Matlab I can recommend the book "Contemporary Optical Image Processing with MATLAB" from Poon and Banerjee.

    Best wishes, 


  • Jeonghwan Kim added an answer in Solubility:
    Does the DMSO solvent influence the tyrosine intensity in Bovine serum albumin?

    My metal complex neither soluble in water nor Buffer. it soluble in methanol,, CHCl3 ... but for the biological convenient i  dissolved in DMSO solvent and dilution with PBS Buffer. During the fluorescence experiment (synchronous ) , in first addition i have found that the tyrosine intensity increases  but decrease in next additions. i have took 1:1 ratio concentration of metal complex and BSA (1x10-6 moL concentration ). i don't know the reason for the anomalous behavior. Should we use DMSO for protein binding study . if it possible kindly help me in this doubt and give some related articles

    Jeonghwan Kim · Okinawa Institute of Science and Technology

    I believe less than 10% of DMSO would be safe for the protein stability. For example, firstly dissolve the metal complex in 1 mL DMSO and then add up 9 mL of basic/acidic buffer in a 1/10(v/v) ratio.

  • Amirmohammad Pasdar added an answer in CloudSim:
    How can I calculate the fitness function of the chromosome?

    how i can calculate the fitness function of the chromosome in cloudlets scheduling to vms in cloudsim ???

    Amirmohammad Pasdar · Ferdowsi University Of Mashhad

    Dear Elhossiny,

    I agree with Mahboobeh, it depends on the definition of your problem. However there are some factors that you might consider and develop your fitness function based on them. For example minimum execution time or minimum completion time might be good factors for fitness function. Also you can deem resource utilization as another factor for your function.


  • Sumit Rathore asked a question in Reticulocytes:
    Is cDNA library for reticulocytes available commericially ?

    Red Blood cell or Reticulocytes RNA c DNA Library