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  • K M Mohsin added an answer in Permittivity:
    What is dielectric constant or permittivity of graphene?

    I would like to know the dielectric constant value of graphene and graphene nanomesh.

    K M Mohsin

    Hi Gopi,

    I am not sure  you still need this information. Anyway check this following link. In this work, they showed field dependence of dielectric constant. Hoping this might help. 


    Let me know if you have trouble in downloading from this link.

  • Chandra Mouli P.V.S.S.R. added an answer in Digital Image Processing:
    How can I extract multiple numerical data from image and take the difference?

    I want to exact multiple numerical data from image 2D(from pdf file).

    and than take difference between two types of data points. eg. from same independent values let say x1 taking difference of two dependent data points(eg. y1,z1).

    I have check WebPlotDigitizer and other similar programs. They give good result for both type of data points separately. But using that type of software i could not get differences as independent value x is slightly different from  the different type of data points(y,z).

    Chandra Mouli P.V.S.S.R.

    Dear Saba Noor

    What do you mean by multiple numerical data from image 2D from pdf. Is the image in pdf format?  How do you choose two types of data points? 

    Do you mean "extract features from a pdf image1 and then extract same features from another pdf image2 and want to find similarity or dissimilarity between two features?

    Please reframe in the question that helps all to think about and give proper question.

  • Gloria Micó asked a question in Water Measurement:
    Does anyone know the molar extinction coefficient of ethanol in water measured at 1550nm wavelength?

    I want to use Ethanol for my study dissolved in water, molar extinction coefficient of which at 1550nm is not available as such. Can anyone help me with the molar extinction coeffienct of Ethanol in water?

  • Lakshmi Devaraj added an answer in Cu Foil:
    Doubt in redox peaks obtained with 2-electrode set-up in Cyclic Voltammetry?

    I am working on SnSb anode material. To check the redox activity of my system I ran CV experiment. I used 5M-aqueous LiNO3 electrolyte for testing. When I use 3 electrode set up WE+Ag/AgCl|LiNO3|Pt CE I couldn't get any peaks at any potential value (even for a wide window -1 to 3 V). Instead transparent electrolyte solution became blue in color. Then I just tested my WE vs Cu foil to see any redox activity occur. With this two electrode set up I got redox peaks. I have attached the CV graphs here. I am wondering how to interpret these values, whether they belong to my WE or any other things? If they belong to my WE how to interpret these..?

    Please clear my doubts which persist for a long period of time

    + 4 more attachments

    Lakshmi Devaraj

    Hello Sir,

    I placed it close to the WE. (to reduce the solution resistance).

    I tried both Saturated Calomel and Ag/AgCl electrode. In the graphs showed in my question I used Ag/AgCl as RE.

  • Shammi Raj added an answer in Meteorology:
    What is a method to obtain quantitative precipitation forecast for a punctual location or area?

    I am trying to evaluate the increment of a river flow in some parts of my country, that's why I need a forecast for precipitation. I tried using models like WRF and ETA, those give me a grid of possible areas where would occur precipitation  and beside it an scale of the amount of precipitable water.

    Is there another method to obtain the quantity of precipitation, as a punctual value, instead of getting a shaded grid with its scale?

    Kind regards!

    Shammi Raj

    Dear Carlos Enciso,

     Did you think of trying the procedure of Model Output Statistics for deriving a punctual value of rainfall. You adopt the stepwise regression procedure with that of any model giving outputs to a grided forecast and it is possible to get a good accuracy for the forecasts. I suggest that you can first test it with an independent data set before you apply it for any operational study.

    Thank you

  • Raju Francis added an answer in Article Writing:
    Who wants to cooperate in article writing?

    I am looking for a young scientist in the fields of organic synthesis, who writes his/her own articles and wants someone to read and comment them before publishing. I want to give you my articles 1-2 times per year as well, to see if it makes any sense for an outsider. Unfortunately, I am not English speaking person. Confidentiality guaranteed!

    Raju Francis

    This is a good idea if all keep professional ethics. We are interested.

  • Ranga Santosh added an answer in Physical Chemistry:
    Anyone knows where can I find a free pdf format of the book: "Quantum chemistry" (MCQuarrie)?
    I need 1 book: "Quantum chemistry" - MCQuarrie and solutions problems of this book. Please help me to find free pdf format of this book.
    Ranga Santosh

    Can you forward it to me .


    Thank you. 

  • Robert J Meagher added an answer in Biomedical Engineering:
    Is biomedical engineering really <engineering> or is it better to study electrical,mechanical or chemical engineering?

    the qoustion of when the biomedical engineering chose,my mind got involved,please give answer to my qoustion.

    thank you

    Robert J Meagher

    Biomedical engineering is a very broad field - it depends very much on the specific department.  Some will be more focused on medical devices which will have elements of mechanical, chemical, and materials engineering; others will have more focus on instrumentation such as imaging which will have more elements of electrical engineering.  Meanwhile if you are really interested in biomedical field, but you major in one of the more traditional engineerings you still will learn a lot of good fundamentals and applied physics, but maybe with applications that are not suited to your interests.  So for example in chemical engineering you may end up learning process control or fluid mechanics as applied to a chemical plant, as opposed to a medical device.  On the flip side, the traditional engineering fields will have wider job possibilities should you decide biomedical doesn't suit you.

  • prof V.S Muralidharan added an answer in Electrochemical Biosensors:
    Why are electrochemcial impedance spectroscopy results not stable?

    I am working on electrochemical biosensor, which measures change of charge transfer resistant for detection of protein. My problem is that the charge transfer resistant keeps changing even if the measurements are repeated on the same electrodes, i. e., after antigen is captured by antibody on working electrodes, multiple EIS measurements did not give consistent results, but kept varying significantly. [My protocol of building the sensor is: attaching antibody to gold working electrode using self-assembled monolayers, using K3Fe(CN)6 and K4Fe(CN)6 as redox probes and doing EIS measurement at formal potenital (about 0.2V) with AC (10 mv from 10kHz to 0.1Hz).]

    Does anyone have the same problem before or happen to know the reason for my problem?

    prof V.S Muralidharan

    see my ppt for stability and linearity

  • Qiang Wang asked a question in Gravitational Redshift:
    How does the gravity affect the frequency of the atomic clock?

    We know we can detect the frequency diffrence between two optical clock located in different height by beating them, known as the gravitional redshift.  And the frequency of the clock would be corrected to frequency at the sea level.  Is the orignal frequency different from clocks? Or the redshift is from the gravity difference between clock and measure point only? And does the gravity affect the transition frequency of the atoms located in different gravity potential? Thanks

  • Julie Lebreton Anberree asked a question in Dolomite:
    Looking for reference on difference between calcite vs dolomite fractionation

    Dear all,

    I am trying to understand the difference in the fractionation of calcite vs dolomite to obtain carbon and oxygen isotope values. I believe that the following reference is essential.

    Rosenbaum, J., Sheppard, S.M.F., 1986. An isotopic study of siderites, dolomites and ankerites at high temperatures. Geochim. Cosmo-chim. Acta 50 (6), 1147–1150

    Has anyone a copy of this reference?

    Thank you for your help,

    Best regards,


  • Paige Brown Jarreau asked a question in Blogging:
    Do you have research you'd like to see blogged about?

    Do you have research papers you'd like to see blogged about in the science blogosphere? I'll blogging about your research over at SciLogs.com, for my science communication research! Please check this out if you are interested:


  • Asiqur Rahaman asked a question in Brain:
    If we consider BBB (Blood-brain barrier) as a wall that protects the brain from outer brain immune stress then from which side does MS initiate?

    MS oriented researchers

  • Martin Bressler added an answer in Business:
    Why do only 13% of business meet their yearly strategic goals?

    According to a study by the Gartner Group only 13% of business meet their yearly strategic goals. What are the reasons for that? How can we improve this situation?

    Martin Bressler

    Based upon my experience (not my research), I have found that most organizations do not do a good job with regard to their strategic planning and also in some instances have found organizations developed unrealistic goals and expectations. 

  • Taher Ahmed Ghaleb added an answer in Forecasting:
    How can Neural Network series be used for forecasting ?

    Suppose i have three inputs and one output. How can I use ANN series for forecasting with my data.

    Taher Ahmed Ghaleb

    These references may help you:



    Also, this is a general reference about forecasting  using ANN


    All the best.

  • Martin Bressler added an answer in Entrepreneurship:
    Do cooperative organisations have entrepreneurial potentials?

    entrepreneurship is a key factor that stimulate economic development and am currently working on how cooperative organization can key into this potential.

    Martin Bressler

    Yes.....though it usually depends on the climate set by leadership of the organization.  If leadership supports, encourages and facilitates entrepreneurship, it will happen.  

  • 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

    Thank you so much Lucio for your excellent remarks , it is now loud and clear and I fully agree.


  • Mazhar Dhankot added an answer in SAP2000:
    With respect to modelling of a confined masonry structure is SAP2000: Can anyone suggest a method to connect the RC tie member with brick masonry?

    Joint between RC tie member and birck masonry is very critical in brick masonry structure. The toothing which is provided in confined masonry structure imparts part fixity with Brick wall. How to simulate that condition in SAP2000?

    Mazhar Dhankot

    Dear Ahmed,

    I was thinking on the same line of action i.e to go for FEM package. 

    Thanks for the your help and suggestions.


  • Anirudh Kumar Satsangi added an answer in Health Psychology:
    Can the span of life be increased?
    Yogi says yes. According to Swami Sivananda, "According to Yoga, man's life is constituted of so many breaths. The number of respiration per minute is fifteen. If you can reduce the number of breaths by the practice of Kumbhak or retention of breath, or stop the breath through Kechari Mudra you can increase your span of life."
    Anirudh Kumar Satsangi

    None has replied to this question so far.  I realize that it was a really difficult question to attempt to respond.  But, today it appeared in The Times of India, New Delhi/Agra that deleting genes could extend lifespan.  Scientists at the Buck Institute for Research on Ageing and University of Washington identified 238 genes that, when removed, increase the replicative lifespan of S cerevisiae yeast cells.  This is the first time 189 of these genes have been linked to ageing.  It provides new genomic targets which could be used to boost human lifespan.       

  • Frank Palmer added an answer in Peristaltic Pumps:
    What is the required pump pressure to handle a MF module in the MBR reactor?

    What is the required pump pressure to handle a microfiltration module in the MBR reactor?

    Can I use a peristaltic pump?

    It will be a lab scale reactor - with flow about 10 L/h.

    Frank Palmer

    It will depend on the feedwater or sludge content.

  • Frank Palmer added an answer in Reverse Osmosis:
    What are typical materials for feed spacers in reverse osmosis? Is there a connection between scaling and the polymer of the spacer?

    I deal with scaling in reverse osmosis. In a spiral wound module for desalinating municipal water we found CaCOprecipitates on the spacer even if deposits were barely visible on the membrane.

    I would be glad if someone could share experience in this area.

    Frank Palmer

    Our experience is that when fouling by CaCo3 and other foulants building on the membrane decrease performance, then after chemical cleaning of the membranes, there is little or no fouling left on the spacers.  When the membrane cartridges reach the end of their life, then they are replaced with new cartridges and new spacers.  In practice it's not an issue.

  • James Williams added an answer in Second Language Writing:
    How does the first language affect the second language writing the first level of ESL students?

    how does the first language affect the second language writing the first level of the ESLstudents?

    James Williams

    Bob Kaplan was the originator of "contrastive rhetoric"back, if I remember correctly, in 1965.  He maintained that there were specific organizational differences inherent in language types.  He described English organization as linear, Romance organization as what I suppose might be characterized as "wandering," Semitic organization a parallel, etc. I have seen several refutations of contrastive rhetoric but no studies in support.  Nevertheless, the idea has survived these many years.

  • Ilya Tsyrlov added an answer in Flavonoids:
    Does anybody know how to properly evaluate protein-flavonoid interactions?

    How can I measure the interaction between a protein and common flavonoids?

    Ilya Tsyrlov

    Hi Erick Paul,

    It’s my strong opinion that the best way to properly evaluate protein-flavonoid interactions is not limited to isothermal titration calorimetry, equilibrium dialysis, surface plasmon resonance, NMR, or the Hummel-Dreyer method. All physicochemical assessments are good but not sufficient enough without functional (enzyme-kinetic, inhibitory) characteristics of flavonoids’ interactions with biocatalytic ptoteins, such as enzymes. To this end, you might find a useful our data on inhibitory analysis of six different flavonoids on the recombinant cytochromes P450s and the P450-reductase (BIOCHIMICA ET BIOPHYSICA ACTA 1205:325-35, 1994).

    In a nutshell, structure-activity relationships indicated the importance of hydroxyl groups in the 5- and 7-positions on the A ring of the flavane nucleus. These hydroxyl groups accounted for the inhibitory potency of chrysin on each of the activities of the expressed P-450s, while presence of a hydroxyl group at the 4'-position on the B ring decreased the inhibitory potency of naringenin compared to that of chrysin. The ortho-orientation of a hydroxyl group on the B ring was of importance, inasmuch as quercetin was more potent than morin as an inhibitor of cDNA-expressed and hepatic microsomal monooxygenases.

    Best wishes,


  • Hugh Lachlan Kennedy added an answer in Tracking:
    How the individual targets states are initialized in the context of multitarget tracking?

    In many papers i have seen that the initial values
    (initial state and covariance) which are given to the estimators are correct values. can any one explain how  one can know the correct values(initial state and covariance)  in prior?

    or in otherwords, in realistic situation of multitarget tracking how can one start the estimation process(choise of initial state and covariance) .

    Hugh Lachlan Kennedy

    A lot of people 'cheat' in simulations by initializing the track state with the true values. I guess this could be justified in cases where the tracker is cued by another sensor or perhaps an operator.

    A more reasonable/realistic approach is to set the position equal to the initial measurement and other higher order time derivatives of position to zero. The initial variance of each state estimate component, if a Kalman filter is being used, is then set equal to the expected velocity, acceleration, etc, of the target. A more subtle form of cheating is when the square-root of these elements matches the actual velocity exactly (or the std. dev. of the generating distribution if an MC sim. is being run).

    I wouldn't feel too bad/guilty about using either approach, so long as it is clearly stated what has been done and why. 

  • Yannapol Sriphutkiat asked a question in Surface Acoustic Waves:
    Can I generate Surface Acoutics Waves on non-piezomaterial substrate ?

    If I have IDT electrode pattern on non-piezomaterial substrate, 
    Can I get the Surface Acoustics Wave which is enough to manipulate fluid or particles ?

    Best Regards,
    Yannapol S.

  • Jaywant Pawar added an answer in Polymer Composites:
    How can I develop the dissolution medium of poorly water soluble drugs apart from official media given in USP/BP?

    Whether it is necessary to compare my developed formulation with the innovator drug release profile in respective dissolution media?

    How to develop a dissolution media for existing API? I want to study How is the technology or polymer composition helping us to improving drug release pattern?

    Jaywant Pawar

    Thank you Vladimir and Mubashar Rehman Sir for the detailed information. 

  • Miaomiao Cheng asked a question in Elements:
    Why use labelled heavy metal elements to study the uptake and translocation of these elements in plants?

    In solution culture, why people use labelled Cd or Zn to study the uptake, translocation and distribution of these elements in plants? Is that necessary? Why? Thank you!

  • James Williams added an answer in Rhetorical Analysis:
    What is statis in Rhetorics?

    The earlier mode of Greek and Roman civilization of Rhetoric analysis.

    James Williams

    In Aristotle's Rhetoric, stasis was a discovery procedure that involved asking a series of questions to determine the point at issue.  The questions involved fact, definition, quality, and jurisdiction.

  • Constantin Polychronakos added an answer in Chromatin:
    What is the relationship between CTCF binding sites defined chromatin domain and disequlibrium linkage group?

    Does the linkage group cross the CTCF defined insulator region/loop region or overlap with the region?

    Constantin Polychronakos

    Yes, information on CTCF binging sites can help you narrow down the gene whose expression is affected by the causal SNPs. A causal SNP can modulate expression of a gene that is outside its recombination interval (LD block). The associated SNP must be within the LD block. The gene affected could be outside the LD block but must be within the interval defined by CTCF sites. However not all CTFS sites have insulator function. Read the references given by Mehreen.

  • A. Subba Rao added an answer in Manure:
    How can we elevate the crop response efficiency of organic manures?

    Organic manuring is known as  an age old agricultural practice . But ,  its relevance in modern day agriculture is proven beyond doubt in the context of iheir multiple roles, including as nutrient source and cleanser of soil contaminants, besides improving soil physico-chemical and biological properties, with the result, crop performance is holistically improved.In this background, i call upon my learned colleagues to respond to my following querries, which will go a long way in clearing some of the intricate issues related organic manuring:

    * What is the effectiveness of different organic manures,  considering their utility as nutrient source versus soil amendment?.

    * Do we need to evaluate salt index of manures to define the quality of different manures?.

    * Whether the quality criteria of agiven manure differ according to type of substrate undergoing composting/.

    * To what an extent , manures alone are effective as compared to in combination  with mineral fertilizers?.

    * Do we need to load the organic manures with PGPRs to improve their responess?.

    * How effective is organic manures in cleansing the soil contaminants/pollutants ( Sieve function of soil ) ?.

    * Which is the best method of organic manuring in perennial trees?. 

    A. Subba Rao

    Dear colleagues,there are problems with raw(dung) manures or immature(not sufficiently decomposed) composts.The acute effects(immediate response by plant) and chronic effects(symptoms slower to develop).The acute effects are due to salinity ,ammonia toxicity and organic(fermentation)acids and chronic affects due to high C:N ratio and phytotoxicity due to excess minerals.Raw poultry manure litter(fresh,wet and not composted) may have salts and  a higher quantity of N in the form of ammonia.Salt together with ammonia may cause injury to seedlings of tomato,pepper etc.High salinity weakens plants and often leads to root rot,those caused by Pythium andPhytophthora ( in crops like soy bean,rhododendron) In USA states  provide guidelines to use manure containing salts-fixing critical limits,composting  ratio of dung to bedding material,application rate,leaching /irrigation after amending the soil with manure.The following  brief note may give some idea of the problem and possible solutions. Can compost damage plants  whatcom.wsu.edu/ag/compost/Compost_Damage.htm.Reprint from Biocycle Sept200,41(9)