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  • How can I do soil amplification and absolute acceleration to vary with material non-linearity?

    What is the global trend of results while comparing linear, equivalent-linear and nonlinear site response analysis? For alluvial valley of Kathmandu valley I found more amplification in case of nonlinear analysis in comparison to equivalent linear analysis. Similarly, the spectral acceleration is found to be more in case of equivalent linear analysis. Does this sound logical in global practice?

    Govind Singh Bhardwaj · College of Technology and Engineering Udaipur

    Soil amplification factors can be determined using distance-corrected spectral ratios between horizontal component ground-motion recordings from soil sites. I think this is authenticated one. 

  • Andrei Gavryushin added an answer in Amines:
    Why do some chemists prefer to perform N-formylation for the free amine before coupling reactions rather than reacting the free amine directly?

    Recently, I've seen in a patent a simple N-alkylation reaction of 2-aminobenzothiazole with ethyl bromoacetate. The inventors have carried out N-formylation reaction first followed by coupling with ethyl bromoacetate. So, I wonder why they did not react the free amino group directly with ethyl bromoacetate? Were they afraid of another side cyclization reaction? If so, what is the role of formyl group in this reaction and also to prevent this side reaction?

    Many thanks and sorry for that long question...!!!

    Andrei Gavryushin · Nanoscape AG


    there is a reference to Organic Syntheses.

  • Jennifer EMELDA asked a question in Solvent Extraction:
    Does enzyme degrade through solvent extraction?

    can anyone explain me the interaction between enzymes and solvent?

  • Yuri Rylov added an answer in Euclidean Geometry:
    Is the Riemannian geometry consistent?

    In the Riemannian geometry the distance between any two points is defined as an integral along the shortest curve (geodesic), connecting the two points. Let the Euclidean geometry be defined on two-dimensional plane L as a Riemannian geometry. Let now we make a hole in L and obtain the plane Lh with a hole. Then the plane Lh will not be imbedded in L isometrically. Does it mean, that the Riemannian geometry is inconsistent? Or following mathematicians, one should consider the Riemannian geometry as a consistent geometry, provided one considers only convex pointsets.

    Yuri Rylov · Russian Academy of Sciences

    Dear Yuriy,

    Do you think, that topology is something external with respect to Riemannian geometry?

  • Haris Hussain asked a question in Fluid:
    I want to design of water(cold fluid) to air(hot fluid) cross flow compact heat exchanger guide the best set of equations for theoretical calculation?

    a water to air heat exchanger is to be designed 

    water temperature is 20C and air is at 40C air is to be cooled with the help of compact cross flow heat exchanger by water.

  • Remi Cornwall added an answer in Maxwell:
    Is electromagnetic radiation produced by the electron's acceleration or a Flip-Flop?

    Since Maxwell suggested that Electromagnetic Radiation (EM-R) is produced due to electrons acceleration, a new mechanism based on the Flip-Flop of electron is recently suggested with comparison to Maxwell mechanism, in a paper title “The Electromagnetic Radiation Mechanism” at: http://fundamentaljournals.org/ijfps/downloads/68_IJFPS_Sept_2014_72_79.pdf

    Do you think the Flip-Flop mechanism offer better explanation?

  • Chandrashekhar Dharankar added an answer in Torque:
    How can we calculate the required torque to rotate 1200 kg of mass?

    I would like to calculate torque to rotate 1200 kg of mass which is attached in 1.5" dia shaft. Shaft is supported by 2 bearings at its end. Neglect bearing frication. Please help.

    Chandrashekhar Dharankar · AISSMS-All India Shri Shivaji Memorial Society

    It depends on the angular acceleration alpha (rad/s) with which the shaft is to be rotated and the mass moment of inertia J (kg-m^2) of the shaft about its axis of rotation. Then use the formula suggested by Sascha Duczek,

    In your case J = Ms*D^2/8 + 1200*r^2 + Jg,

    D = Shaft dia, Ms = mass of shaft,

    r = distance of CG of the attached mass from the centre of rotation,

    Jg = MI of the attached mass about an axis through its CG and parallel to the axis of rotation.

    Hope this will help.


  • What is the impact of political violence on individuals and groups personality and behaviors?

    Dear friends ,

    any information that may help in my research? 



    Mary Abu-Rakabeh · University of Liverpool

    Many thanks dear Steven. very useful and much appreciated 

  • Philia Wang asked a question in FRAGSTATS:
    How does "Spatial Statistics (by Regions)" work in arcGIS?

    How does "Spatial Statistics (by Regions)" work in arcGIS? 
    I don't really understand what "class layer" and "regional layer" means?
    Why I can only choose raster files in "class layer" and shp files only in "regional layer"?

    I have several sites in format of shp files. I want to calculate every site's area metrics, proximity metrics and several...(both in landscape and class level).

    Actually, I have tried to calculate in "Spatial Statistics (Fragstats Interface)"...but it didn't work. 
    And now, I found (By Regions) can work!

    How to make sure the coming out metric numbers are correct?

  • Mathias Schlögl added an answer in Anti Obesity:
    Is there any human study on Irisin hormone?
    See above
    Mathias Schlögl · University Hospital Zürich

    There are many already, here my latest one on irisin and food intake in humans:


  • Is the electron mass strictly of electromagnetic origin?

    There exist   theoretical evidences that this hipothesis is true, especially, it is strongly supported by the Casimir type electron stability mechanism suggested by Prof. hal Puthoff in his nice work: Putho¤ H.E. "Casimir vacuum energy and the semicalssical electron". Int J Theor Phys, 46, 2007, p. 3005-3008, as well as in the work by Valerii B Morozov,  2011 Phys.-Usp. 54 371 doi:10.3367/UFNe.0181.201104c.0389
    "On the question of the electromagnetic momentum of a charged body"

    Anatolij K. Prykarpatski · AGH University of Science and Technology in Kraków

    dear Eugene,

    really, - your remark above  is looking here geometrically substantial concerning manipulations with  true fundamental constants.


  • Mere Vadei added an answer in Likert Scale:
    What is the problem with using only 4 categories in a Likert scale (Strongly disagree, Disagree, Agree, Strongly agree)?

    I am trying to develop an instrument (a survey questionnaire) to measure teachers perceptions about use of assessment data.

    Mere Vadei · Secretariat of the Pacific Community

    Indeed, thanks for the practical comments. Appreciated truly.

  • Nalin Sharma asked a question in CAx:
    How to find a partial derivative with respect to a matrix?

    Let we have a 2x2 matrix A= [a1 a2;a3 a4], 1x2 matrix C, 2X1 matrix x. How can we calculate derivative of (CAX) with respect to matrix A.

  • Sanjay Kumar added an answer in Peer Reviewed Journals:
    Could you please suggest me few reputed referred journals to publish research article on SME Cluster Development Issues without processing fee?

    Please suggest me name and website address of few reputed referred journals to publish research article relevant to SME Cluster Development without processing fee. 

    Sanjay Kumar · IITM, MURTHAL

    Dear Professor,

    You may have some journals at DOAJ- Directory of Open Access Journals.


    Thanking you with warm regards.

    Dr Sanjay Kumar.

  • Galinoma Lubawa added an answer in E.G:
    Suppose am analyzing the data collected on "Factors influencing consumers to purchasing online; what will be the appropriate data analysis?

    My aim is to know  technique  for data analysis, e.g ANOVA,CHI-SQUARE or multivariate regression, MANOVA or ........... help me please

    Galinoma Lubawa · Institute of Rural Development Planning

    Thanks you all for tremendously contribution. 

  • Waleed Ahmad added an answer in GRAMS:
    Cobalt nitrate hexahydrate to cobalt oxide?

    I want to know 1 mole or gram of cobalt nitrate hexahydrate gives how many grams or moles of Cobalt oxide. is there any kind of equation for that? or is there any general rule? I found in literature if we heat the cobalt nitrate it would eventually gives cobalt oxide but i want to know mathematical relation?

    As i need 2 grams of cobalt oxide so how many grams of cobalt nitrate hexahydate would be used which ultimately would give me 2 grams of Cobalt oxide. I will heat it till 450 degree centigrade 

    Waleed Ahmad · National University of Science and Technology

    Really thanks a lot i got my answer 

  • Shiwei Mo asked a question in Injury Prevention:
    How can I test the proprioception under a dynamic posture condition, like walking or running?

    About proprioception, many researches have reported that it is very important for injury prevention, and they are variety of tests and loads of measure devices and methods. However, all proprioception data in these related papers I read are attained under static posture condition, e.g. sit on a chair, stand without any movement. All these data is very useful for further understanding proprioception, but if I want to know more about how the proprioception work under a dymatc posture condition, for example how the proprioception work for preventing running injuries?

    So I just want to ask how can I get the proprioception data when I am running but sitting on a chair? Is it possible to measure the proprioception under dynamic posture condition as there are too many influence factors, how can I do it?

  • Sankit Kassa asked a question in CMOS:
    How to find Static Power for a simple CMOS NAND gate?

    When we give constant input (eg. either 0 or 1), its called Static Power dissipation. So how to find total static power dissipation? for NAND2 gate, is it the average of all this different combination (0,0), (0,1), (1,0), (1,1) or we should take the minimum/ maximum out of one of all this inputs as a static power dissipation?

  • Natalia S Duxbury asked a question in Chemical Physics:
    Is the effect of "BUBSTONES" well known in chemical physics?

    "BUBSTONES"= Bubbles stabilized by ions

  • When it comes to simultaneity is Einstein correct or is Dingle correct?

    Albert Einstein claimed in 1905 that a single event can occur simultaneously at different times within two inertial reference frames moving relative to one another. In 1950 Herbert Dingle argued that different times cannot be simultaneous. I have analysed this conflict by deriving the Lorentz equations using both points of view. According to this analysis Dingle must be correct. See youtube presentation of this analysis at  https://youtu.be/4XLYzhHQ64Y

    Charles Francis · Jesus College, Cambridge

    "Funnily enough, remote means they do not co-exist together."

    That was not my full explanation, just the summary of it. You just took it out of the context with the actual explanation, which followed. 

    No, your full explanation was that you had a magical way of synchronising clocks, which no one has been able to observe, and which is in direct contradiction with what has been observed. 

    "You also claim to synchronise clocks by instantaneous messaging."

    "No I never claimed such a thing."

    You did, valentine, since every method using light or the physical behaviour of matter obeys laws of physics governed by the Lorentz transform. Even if there were such a thing as "transversal communication between frames" you could not use it to establish an absolute synchronisation without instantaneous messaging. As it is, you are just making up words to describe something which does not even exist.

  • What is the molar extinction coefficient for polyphenol oxidase?

    Kindly give me inputs on this.

  • Martin Schulz added an answer in Motor:
    What is the ratio of energy efficiency of BLDC motor to the Permanent Magnet motor and induction motor?

    Brush Less DC Motor is more energy efficient then the Permanent magnet motor and induction motor.

    Martin Schulz · Infineon Technologies

    Dear Mostafa,
    giving a Wikipedia number always is a dangerous thing to do :-)

    Especially if general statements like "P=VI" are given which scares me quite heavily :-)

    To my knowledge, the electric power should be Pel=Uline-to-line*I*cos(phi)*sqrt(3)

    Correct me if I'm wrong...

  • Babak Nouri-Moghaddam asked a question in SNA:
    What are the new areas in Social network analysis?

    I want to start my research for my thesis, and looking for new subjects in SNA. I've basic knowledge of SNA, and complete understanding of Data mining and meta-Heuristic topics.

  • Data Fitting Procedure in Electrochemical Impedance Spectroscopy to find Resistance and Capacitance?

    I have data for my EIS experiments. I have already copied data into excel sheet. Most of the papers mentioned that they performed data fitting procedure to find resistance and capacitance. In my understanding, we can NOT report resistance and capacitance directly from experiment. Anyone up to help me in this?

  • Critical Literacy in the 21st Century: Why it is so important?

    Critical literacy is the ability to actively read text in a manner that promotes a deeper understanding of socially constructed concepts; such as power, inequality, and injustice in human relationships. Critical literacy encourages individuals to understand and question the attitudes, values, and beliefs of written texts, visual applications, and spoken words.

    The development of critical literacy pushes students to question issues of power; in essence, to become thoughtful, active citizens. Becoming critically literate means that students have developed and mastered the ability to read, analyze, critique, and question the messages inherently present within any form of text. Your inputs will be highly appreciated. 

    Paul Louangrath · Bangkok University

    In every age, literacy always aims to build critical thinkers for society---hence the aim of education. How much of this aim had been achieved is a matter of social conditions and availability of resources (or accessibility) of the particular society. Although critical thinking seems to be more "critically needed" in the 21st century because of the complexity of the current human society, yet the aim of literacy (education) remains the same: uplifting the human spirit.

  • Nalin Sharma added an answer in State Space:
    How to find a valid steering actuator model (state space or transfer function) for a car like ground vehicle?

    I want to control the lateral dynamics of a car like ground vehicle for implementing automatic behavior (such as lane change, side slip control). please suggest me how to find or develop a steering actuator model in terms of state space or transfer function. How to design a genuine actuator for steering?
    Any help will be appreciated.

    Nalin Sharma · Indian Institute of Technology Delhi

    Though there are techniques of modelling of actuator, but as your main objective is to control the dynamics of car, you need not to know model of steering actuator. First of all you must know the dynamics of ground vehicle. According to your control objective you design a control technique, you damp it in controller, on the basis of control algorithm controller gives output to the steering actuator in voltage. The relation between voltage and steering is given in the data-sheet of a particular actuator. Later you can set the voltage of controller according to your steering demand. Once i used the same procedure for controlling passenger car and it worked.

  • Dino Aquilano added an answer in Calcium Sulfate:
    Can I use X-ray photoelectron spectroscopy XPS to analyse surface properties of gypsum (calcium sulfate dihydrate) crystal?

    Hi all,

    I want to analyze adsorption of phosphonate on gypsum  (CaSO4.2H2O) crystal. I want to know if I can use XPS or not. Someone told me as XPS performs in vacuum then gypsum might dehydrate. what is your opinion.



    Dino Aquilano · Università degli Studi di Torino

    Dear Taher,

    CaSO4x2H2O (gypsum) is a stable compound, at room temperature and pressure, since the two water molecules are strongly bound to the crystal structure.

    We carefully observed its growth morphology under the vacuum of SEM (Scanning Electron Microscope), along with its structure (with  the TEM vacuum) and no transformation occurred to the other hemi-hydrated phase. 

    Then you must control the temperature; obviously, when working under vacuum and the temperature rises to 120°C, this may be dangerous. But, I suppose, this is not your case.

    All the best

    Dino Aquilano

  • Could anybody give a reference to the online full text of this publication (see below)?

    This is the reference to the publication that is needed online:


    Buryak, Aleksey K.

    Успехи наук о жизни. 2013. № 6. С. 84-86.

  • How to define cyclic frequency for cyclostationary signal in terms of signal parametrs?

    I am trying to detect cyclostationary signal. For that it is required to know its cyclic frequency. But I am unable to figure out how it can be related to signal parameter. Is it possible to define exact value of cyclic frequency or its a range of value in which it can exist.

    Suppose we have amplitude modulated signal

    • dt=0.01;
    • fs=1/dt;
    • fm=1;
    • fc=30;
    • t=0:dt:1-0.01;
    • A=2;
    • n=length(t);
    • mt=sqrt(2)*cos(2*pi*fm*t);
    • S=(A+mt).*cos(2*pi*fc*t);

    Now I want to know how to define cyclic frequency suppose alpha for the above signal in terms of signal parameters.

    Vincent Savaux · École Supérieure d'Electricité


    even most of the techniques of the literature require the cyclic frequency, it is not mendatory. Some methods perform blind detection and also blind estimation of the cyclic frequency as :

    Z. Khalaf et J. Palicot On the Use of the Sparse Property of the Cyclic Autocorrelation
    Function to Blindly Estimate the Cyclostationarity , Frequenz, issn
    2191-6349 vol. 66, issue 9-10, pp. 279-292, 2012.

    Z. Khalaf, A.Nafkha et J. Palicot Blind cyclostationary feature detector based on
    sparsity hypotheses for cognitive radio equipment , The 54th IEEE International
    Midwest Symposium on Circuits and Systems, Seoul, Korea, Ao^ut 2011

    Z. Khalaf, A.Nafkha et J. Palicot Blind Spectrum Detector using Compressed
    Sensing , IEEE GLOBECOM 2011 Houston, Texas, USA.