Q&A

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  • Naimish P Sardesai added an answer in EDC:
    What will the form of solution after adding 75:15 mm of EDC and NHS respectively into water?

    N-hydroxysuccinimide(NHS) and EDC(1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide) are expected to be water soluble.But my solution gave semi-ester form with  two immiscible portion of solid and water.If anyone is working with this system, please describe me the final form solution.

    Naimish P Sardesai · McGill University

    To the best of my knowledge this reaction is not temperature dependent. If you are using the Gold surface, please see this paper attached below from our group.

  • From geopolitical point of view, how real is the possibility that Iran returns on global gas market and replaces Russian gas?

    With 18 percent of total world gas reserves Iran is right behind Russia....

    Behrouz Ahmadi-Nedushan · University of Yazd

    South Pars gas field is one of the largest independent gas reservoirs in the world lying on the territorial border between Iran and the State of Qatar in the Persian Gulf. It is one of the country's main energy resources.

    This gas field covers an area of 9700 square kilometers, of which 3700 square kilometers belongs to Iran. The Iranian portion is estimated to contain some 14 TCM of gas reserves and some 18 bn bl of gas condensates. This amounts to roughly 7.5 % of the world gas reserves and approximately half of the Iran’s gas reserves.

    Presently, some precise and sophisticated projects have been designed for development of 24phases to produce 790 million cubic meters of gas per day. South Pars gas field development shall meet the growing demands of natural gas, injection into oil fields, gas and condensate export as feedstock for petrochemical industries.

    An iranian official said China, Japan, Ukraine, Russia, United Arab Emirates, India, Turkey, Iraq, Taiwan, Thailand, Malaysia, Armenia, Mozambique, Egypt, Qatar, Tanzania, Philippines, Kenya, Azerbaijan, Georgia, South Korea and Mexico are among destinations.

    He said that international sanctions have not had any impact on South Pars’ exports to European and American countries.

    South Pars exported 892,000 tons of gas condensate worth $807 million dollars in one month. Gas condensate accounted for half of the products exported from South Pars.

    Pars Special Economic Energy Zone is located in the Persian Gulf and is 105 kilometers away from the massive South Pars gas field.

  • Anush Arunachalam asked a question in Abaqus:
    Total arc length in ouput is less than input arc length in static riks analysis why???

    In Abaqus,Static riks analysis- I have to do tensile test on a composite with cohesive interface.

    1. a)Input -  Total Arc length is 0.5 , b)0.001as initial increment ,c)no of increments 500

    2. Output: No errors arise from the output but in  output the total arc length is 9.23e-2 and what may be the reason for this??

  • Is myth an essential component of political discourse and political practice?

    Even in modern times myth has served as a fundamental ingredient of politics: idealization of leaders, of historical events, of the origins of a community or a nation, are some of the most common. Myth and structured mythologies have played several essential functions in human life: 1) cognitive: myth explains the origin of all things, the reason of their existence, why is life as it is; 2) ontological: it roots human life in a cosmos and its archetypical order; 3) moral and psychological: it presents the conflicts inherent to human existence, the relation between interior conscience and the external world, offering harmonious solutions to those conflicts; 4) social and political: it creates the codes of collective identity, unifies the beliefs of social groups and legitimates social and political institutions.
    However, we should distinguish between traditional myths that have a religious character and modern myths, which are predominantly profane.

    Rafael garcia velasco · National Distance Education University

    Ok, sorry. Would you just for a general purpose and to end this spin-off the discussion: dare to give a reliable definition of culture please?

  • What are values of UNIQUAC pure component parameters r and q for 2-ethylthiophene?

    I want to correlate some experimental data by universal quasi chemical activity coefficient (UNIQUAC) model and I need UNIQUAC parameters r and q for 2-ethylthiophene. Can anybody help me to find out these values? Thanks in advanced. 

    Peyman Fasahati · Pukyong National University

    I got these numbers for UNIQUAC from Aspen V8.6 data bank (APV86.PURE32) :
    (GMUQQ = q =  3.248) molecular area parameter for UNIQUAC activity coefficient model

    (GMUQR = r = 4.24984) molecular volume parameter for UNIQUAC activity coefficient model,

  • Md Rahman asked a question in Scientific Research:
    Why should academic result of any specific stage be always the first criteria for granting fund?

    Whenever you are applying for fund for your academic or research work the first criteria becomes the academic result of either first degree. One can have difficulties during the period of that specific time of graduation for which s/he can get lower grade. S/he might be good at research and professional work. But still that result comes first as a criteria of granting fund. Moreover, how we compare result from different context and institution? 

  • Sohel S Shaikh added an answer in Designs:
    Can anyone tell me what is criteria of determination of low and high value in Plackett-Burman (PB) designs?

    What is the criteria of determination of low and high value in Plackett-Burman (PB) designs?

    Sohel S Shaikh · P S G V P Mandals ASC College, shahada

    can you please send me copy of article if you have?

  • Can you introduce me some references for values of mean and standard deviation of DG probability distribution function in a 24-h PS operation problem?

    I am going to model uncertainties exist inherently in a power system operation problem in the presence of renewable energies. Can you introduce me some papers as references for typical  values of mean and standard deviation of DGs(wind turbines, solar panels) and load probability distribution function  in a daily operation of an electric power system?

    I look forward to receiving your reply.

    Regards,

    Akbar

    Morteza Shabanzadeh · Tarbiat Modares University

    Dear Akbar,

    See the papers of Professor Seifi which are available in the following links.

    Regards,

    Morteza

  • Shridhar Kinkar added an answer in Fermentation:
    Which are the recommended hosts for a large-scale expression of human Fabs?

    I want to express the human Fabs in E. coli, the literature shows HB2151 strain is a preferred choice for the same. But I need to make Fabs at levels that should be considered good enough to take forward at production scale. I was wondering if we can use BL hosts, but for them very confusing results in the literature are reported. 

    The inputs will be very helpful in taking the experiments ahead.

    Regards

    Shridhar.

    Shridhar Kinkar · Gennova Biopharmaceuticals Ltd

    Hi Jai,

    Thank you for the reply, but the point is HB 2151 cannot be used for the large scale expression.

  • Manoj Kumar Singh added an answer in Energy Saving:
    What are the methods to evaluate the energy saving potential of a building envelope?

    Is there any particular software/ method designed to evaluate the energy saving potentials of a building envelope?

    Manoj Kumar Singh · Integrated Research and Action for Development (IRADe)

    I work in the area of building envelope optimization and thermal comfort. Building envelope is the prime factor that determines energy efficiency of the building (fluctuation in indoor thermal environment determines comfort and to restore comfort energy is used by running heaters in winter and air conditioners in summer). Its optimization must be done before constructing the building. Various software's are available to do that such as TRNSYS, IES, Energy Plus and so on. Some thumb rules and guidelines are also available related to U values, Ventilation rate, window to wall ration, Use of glass on external façade and type of glass for glazing (double or triple), internal and external insulation and so on.

    Above mentioned software's can be used to calculated the improved time of comfort in built environment and also the reduction in energy consumption to restore comfort. This way performance of building envelope can be evaluated.

    I will advise you to look into my publication to know more about role of building envelope in determining indoor thermal environment and comfort. 

  • Rosalin Sahoo added an answer in Cell Culture:
    How can I get an even spread of cells in a 24 well plate?
    Does anyone else have an issue with evenly spreading cells in a 24 well plate? No matter how careful I am, the cells (MG-63) huddle mostly in the middle of the well in the outside wells of the plate. The wells in the innermost part of the well don't appear to have the same problem. Is there anything any of you specifically do which can prevent this?
    Rosalin Sahoo · Lonza

    I find pre-incubation of the plates with little amount of media at 37degree very helpful. 

  • Daniel S Helman added an answer in Creativity:
    How can constraint contribute to creativity and formation of a personal artistic style?

    Can invention of a constraint or a set of constraints to the creative process contribute valid artistic effects? How is constraint different from a concept? I am also looking for visual artists applying the "oulipian" principle and publications which could enhance my understanding of the subject

    Daniel S Helman · Founder / Research Scientist

    I'll add an answer:

    In the painting and drawing that I've done, there often is a point at which I've made a mistake, and the work is spoiled.  It's only then that I really, really step up my efforts, in order to salvage what I've put so much work into.  And I just keep making changes until the work is again balanced.

    I'd call this an emergent creativity that follows an emergent constraint.  Yes, you can plan for this, and it's also interesting to add constraints to your art process.  This is how one's skill builds!  It is a good professional practice!

  • What is the impact of mentoring on the development of PCK of teacher candidates?

    Practical courses in teacher education programs are considered as a „bridge between theory and practice“. They are estimated to support the development of Pedagogical Content Knowledge (PCK). Especially reflective dialogues about teaching experiences – for example reflections on school lessons are considered to be useful: Dialogues with fellow students, with experienced school teachers or with their university lectors. Results that underpinned this estimation we could gather within the European project GIMMS (Lang, M. and Simmie - Mooney, G. 2013; Elster, D. 2013).

    What characterizes reflective dialogues on school lessons? Are there differences between dialogues conducted with fellow students, school teachers or university lectors? What is the contribution of these reflections for the professional development of the students? How is PCK promoted by these reflective dialogues?

    We are looking for actual research about mentoring concepts in teacher education with the goal to share experiences about mentoring approaches in preservice science teacher education in different countries.

    Jaroslav Vávra · Technical University of Liberec

    Dear Doris,
    I recommend the following reading: 
    Biggs, J., & Tang, C. (2011). Teaching for Quality Learning at University. Maidenhead: Open University Press.
    For my position as an university mentor is important applying the SOLO taxonomy.
    The Structure of Observed Learning Outcomes (SOLO) taxonomy is a model that describes levels of increasing complexity in student's understanding of subjects. It was proposed by John B. Biggs and K. Collis 1982. (en.wikipedia). It is in accordance to PCK.

  • Odontuya Davaasuren added an answer in MBBS:
    Can you help me design a CBME program for 3rd year MBBS students in diarrhea prevention and control?

    I am a student of Heath Professional Medical Education. I need to develop a community base medical education (CBME) program for 3rd year MBBS students in diarrhea prevention and control with special reference to: a. Water Supply b. Environmental Sanitation c. Availability of Health Services. I am stuck and not getting through it. Can anybody pull me out.

    Odontuya Davaasuren · Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia

    Start with reading environmental health and other articles.  You can find many information from the internet.

  • Tahir Abbas added an answer in Superconductors:
    What materials in nitrogen temperature are superconductor?What materials in helium temperature are superconductor?

    What materials in nitrogen temperature are superconductor?What materials in helium temperature are superconductor?

    Tahir Abbas · Bahauddin Zakariya University

    Classical superconductors, usually metals and alloys show superconductivity at liquid helium temperature. They form cooper pairs at that temperature and show superconductivity.

    Oxide superconductors, also called high temperature superconductors show superconductivity at liquid nitrogen temperature. The phenomenon of superconductivity in high temperature superconductors is not very well understood yet.

    A fairly comprehensive list is avaialable at: http://en.wikipedia.org/wiki/List_of_superconductors

  • Neeraj Sethiya added an answer in Herbal:
    Kindly let me know what's the best way to qualitatively and quantitatively identify Menthol in a herbal formulation (herbal tea in granular form)?

    Should it be GC-MS?

    Also, if we are testing same formulation's sample few months apart, menthol being volatile is liable to decrease with time? Yes / No

    How to maintain the stability of menthol in a granular formulation?

    Thanks in advance & Regards!

    Neeraj Sethiya · The Maharaja Sayajirao University of Baroda

    Please refer these

  • Ricardo gonzález added an answer in Hypospadias:
    How do hypospadiac boys urinate before and after repair of distal defects ?

    The voiding pattern in hypospadias cases differ from that of normal boys and the Qmax mostly around the 25th percentile. After repair shape of the curve, Qmax and Qave could be different from normal

    Ricardo gonzález · Auf der Bult-Zentrum für Kinder und Jugendliche

    Dr. Aldahshoury´s answer is the conventional wisdom, however, when you have a patient post hypospadias repair with an obstructive flow and dilate the urethra or correct the stricture, the flow becomes bell shaped, An obstructed flow (less than the fifth percentile or plateau) means obstruction. The obstruction may remain asymptomatic for years since when the repair is done before toilet training the child does not know how normal micturition should feel. This is in contrast with acquired strictures in adults who are always symptomatic. 

    Urinary flow measurement must be part of the long term follow up after hypospadias repair.

  • Emmanuel Curis added an answer in Standard Error:
    What is the difference between asymptotic standard error and standard error?

    I know about standard error, but not getting idea about the asymptotic standard error and how it is related to standard error.

    Emmanuel Curis · Université René Descartes - Paris 5

    @ Scott: the standard error of the mean computation, as σ/&sqrt;(n), does not rely on the normal approximation or the central limit theorem, it only assumes that observations are independant, identically distributed and have an expectation and a variance.

    Additionnaly, a symmetrical distribution avoids pitfalls in the intuitive interpretation of thhe standard error of the mean (nd standard error also, by the way).

    Central limit theorem (normality) is « only » required for building confidence intervals or making tests on the mean.

  • How to hook up the output of a PMT to a PC for time dependent signal analysis?

    I like to hook up the output of a PMT (R928 Hammamatsu) to a PC to see time dependent optical signal. Could you please suggest me the possible options? Any help would be really appreciated.

    Manoj Kumar Saxena · Fiber Sensors Lab., Raja Ramanna Centre for Advanced Technology

    Th output from a photo multiplier tube (PMT) is basically a current signal. It may be converted to voltage by passing it through a low noise 50 ohm resistor. The voltage is typically of negative amplitude because of use of negative (~ -1kV) dc bias to PMT. Once the voltage is available, it may be amplified using a voltage amplifier if it output is too low else voltage can directly be used.

    Instead of using 50 ohm resistor and amplifier one can also choose a trans-impedance amplifier available from Hamamatsu, Japan.

    This was how to obtain analogue voltage from a PMT. Now, this voltage  can be obtained on PC in several ways as suggested below:

    1) First method: Feed the PMT output voltage to a digital storage oscilloscope (e.g TDS 2024 from Tektronix). See the waveform on one of its channel (Ch1, say). Connect DSO to PC via RS232 link/GPIB port . Use a DSO driver on PC to view the DSO screen on PC.

    2)Feed the PMT output voltage to a digital storage oscilloscope (DSO) (e.g TDS 2024 from Tektronix). Write your own simple driver using RS232 commands to acquire sampled Ch1 (where PMT output is connected) on PC.

    3) Third Method: Use a data acquisition card (DAQ) from NI or Dynamic Signal, USA or from any brand with sufficient sampling rate, band width and vertical resolution (i.e. number of bits. e.g. 8, 12 or 16). Connect the output of PMT to DAQ's analogue channel input. Use its DAQ's driver (Lab VIEW or Matlab based) to acquire the sample in PC.

    Once the samples are available , one can easily play with these for further application development.

    Hope these suggestion help you.

    Manoj Kumar Saxena

    Scientist.

    Raja Ramanna Center for Advanced Technology. Dept. of Atomic Energy,

    Govt. of India

    Fiber Sensors Lab. Indore, India.

  • Does anyone experience citrate gold nanoparticle nonspecific binding?

    I'm trying to couple carboxylated nanoparticle with a biomolecule which has thiol group at the end, later I use that thiol group to couple with citrate gold nanoparticle to make a fluorescent quenched nanohybrid.

    But I experienced a really weird situation, that when I activated carboxylated nanoparticles with EDC/NHS (MES buffer pH 6) and then put them into citrate gold nanoparticle solution, I experienced non specific binding of citrate gold onto carboxylated nanoparticle. I tried to modify some PEG (MW 5000Da) onto gold surface to minimize this nonspecific binding but it didn't help. It's really annoying since repeated sonications still didnt work out for me.

    Any suggestion would be really appreciated,

    Rostislav Váňa · TESCAN,a.s.

    Au@Citrate particles are realy not stable, which is caused by massive non specific binding to anything, even to negatively charged surfaces (should be repelled by elstat force) - this is my experience.

    My questions to you:

    How did you measure non-specific binding of Au@cit particles to the Au@EDC/NHS ones? Are they really binding to the other particles or only they agglomerate themselves (talking about Au@cit)?

    Adam asked you very important question. Any charged molecule can enhance clustering.

    Possible solution:

    I don't reccomend PEG for passivation. Try to use some shorter easy molecule - some thioalkanes should be fine. But it will be more challenging to bind them to anything else afterwards.

    I would suggest to read our work, but since any journal haven't accepted our manuscript yet, I can't :(

  • Sagar Singh added an answer in Copyright:
    Is there an online resource that will produce simple geographic and geo-political maps for user defined areas in Jpeg or another electronic format?

    Copyright issues are a secondary concern as their principal application will fall under the terms of 'fair use'

    Sagar Singh · IIT Kharagpur

    Yes I think Generic mapping tool is best for that !

  • N. P. Badgujar asked a question in Paint:
    How can use pigment tinters for making of paint?

    charge ratio, methodology, equipment used etc.

  • Samer Semrany added an answer in Kinetics:
    Can a logistic model represent the first order kinetics of a reaction?

    I plotted a product concentration changes versus time throughout a reaction. Then I did a regression analysis and fitted the best logistic function (Y= (a / 1+EXP-k(t - b))+ Y0 ) to the recorded data. The logistic fitting model was based on a suggestion in a prestigious reference article.

    In the other hand I read somewhere else in another prestigious reference paper that the reaction follow the first order kinetics (Y= 2(Y0)(1-EXP(-kt))).

    (k: rate constant; t: time; Y0: initial concentration; Y: concentration at t; a: the range of Y variation; b: inflection point or the point at which dy/dt is maximum)

    Considering the equations, can the logistic model represent the first order kinetics? If no, which order?

    Samer Semrany · Ecole Nationale Supérieure de Chimie de Rennes

    Yes it surely can ... but the model will be less significant because logistic has three parameters to determine (a, b and k) and exponential model (first order) has only one parameter (k). So, yes logistic can fit the points even with a higher R² but with lower F-value and higher p-value.

  • Pratik Mitra asked a question in Graphs:
    How to plot p/p0 vs x/H in paraFOAM ?

    How to plot the non dimentional graph in paraFoam.

  • Dejan Dragan added an answer in Simulation Modeling:
    What are the best tools for simulation and modelling?

    Hi,

    I wanted to know what are good tools for simulation and modelling and does it really need a tool? Can't we build our own software for out own system?

    I am new to this field only thing i know is there are two parts is such system 1) mathematical modelling 2) Graphical representation ( Its my perception need not be true).

    So can we mathematical modelling implement using any object oriented language and for graphical part we can use some tool to reduce efforts and time.

    Also suggest me some material that must be required to enter into field of simulation and modelling.

    Thank you.

    Dejan Dragan · University of Maribor

    I agree with prof. Armin. For example, if you are using Matlab or Scilab, they are quite general and flexible, but probably some (programming and other) efforts would be needed to adapt them into your problem. On the ohter side, there are many less flexible softwares, but the question is if they can exactly fit into your problem by only using some parametrization.

  • Maria Kozlova added an answer in Filamentous Fungi:
    Can anyone tell me how I can get cell-free or mycelium free contents of filamentous fungi?

    I want to perform microbial transformation of some xenobiotics with intact fungal organelles, but no cell wall or cell membrane of fungi.

    So I need a way to remove the fungal cell wall and cell-membrane in a way that organelles should remain intact.
    I know that detergents can work better for removing the cell membrane but there is a chance that detergents can also destroy the membrane of the other organelles.

    Maria Kozlova · State Oceanographic Institute

    I can search for  it in my library and scan but as it takes some time I unfortunately cannot do this  too soon. 

  • Jaianand .K added an answer in Serotyping:
    Does anyone know the serorype of the E coli strain BL21?

    I cannot find the serotype of this strain. I know it is derived from E. coli B, but could not find its serotype either. I would appreciate if anyone could show me a reference where I can find this piece of information.

    Jaianand .K · Dr.M.G.R.College and Research Institutions

    As you can try to get the BL 21 strain from Dept of Mol. Bio, Syngene International Pvt. Ltd, Bangalore, on request

  • Om Prakash asked a question in Immunosensor:
    Immunosesnor vs ELISA. Can any one let me know distinguish advantages of immunosensor over ELISA?

    I have read a lot of articles and review articles regarding immunosensor, in the articles researcher compares the sensitivity of immunosensor vs ELISA. But other than this, I could not any distinguish advantage of immunosesnor over ELISA? Could anyone let me know the advantages of immunosensor over ELISA?

  • Mohit Jamwal added an answer in Social Media:
    Hi, i am looking forward to research on Social media and consumer behaviour. Any thoughts?

    Indeed, most journals and articles that i found is more likely related with social media and consumer behaviour and could not keep up with the massive information . But, alternatively, i found that "Passive & active user behaviour in social media" is more interesting. What do you think?

    Mohit Jamwal · Hemwati Nandan Bahuguna Garhwal University

    Great topic to explore... Since the purchasing media changed to digital one, thereby, boosting the companies to shifting some percentage of sales from online web portals to social media sites as these have a huge customer base. Yeah it would be a matter of good research to explore the field deeply.

    Take a look a some studies:-

    Forbes, L.P.. (2013), "Does Social Media influence consumer buying behavior? An investigation of recommendations and purchases", Journal of Business & Economics Research.

    Williams T. and Williams R., (2008). Adopting social media: Are we leaders, managers or followers? Communication World, 25(4), 34-37.

    Hope it helps..!