Q&A

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  • Ji Qing Tan added an answer in Actuators:
    Do you want to be a reviewer when I want to submit this paper to science?

    A trend of the anomaly of global land surface temperature (GLST) had been numerically simulated perfectly by me with a group of simple periodic mathematics functions, which is obtained  with a numerical-functional-analysis-modelling technique in a computer. The result means the modern climate change may be not dominated by human influences due to  the function which perfectly fits the actuate anomaly of GLST from 1880 to 2013, is periodic rather than an irreversible function.  When I ask a question" Is global climate change due to human influence?",which receive more than 341 people concerning by this topic , and there were 12 followers and 13 answers. I hope one of them can be a revierwer when I send it to science magazine, besides, anybody else had the experiences to have been a reviewer for a paper submitted to science magazine is welcome!

    Ji Qing Tan · Zhejiang University

    Dear Muchael patriksson,

            However, in China,due to our gorvenment support Global warming, experts who disagree with GW is difficult to apply for any funding even if the project is not about GW.

          The recent discovery of my work has already to give presentation, many students

    stand by my sides but the professors of our department were unwilling to be as reviewers for this paper. I told all the data can be opened to them , even calculation scheme.

          But no one are willing to be reviewer of this paper. Some good friend of mine told me that if you want to me to be reviewer of your paper, but I can't say positive words to your paper simply because I don't want to be in your stutus ,who nobady dare to cooperate with you and no fundings.

  • Is there a way to specify how many cores a program should run - in other words, can I control where the threads are mapped?

    Can I run a multi-threaded program and specify how many cores should be used: 1, 2, 4 etc. so as to enable a performance comparison?

    Parallel processing

    Multi-core systems

    Pierre Leonard · French National Institute for Agricultural Research

    Hi Ygal,

    As you see you have plenty of answers.. The question is what do you think with many cores. But good answers are here. You want to benchmark a multi-thread program. With openMp the answers are good. but be carreful. Is your server multi-socket. In that configuration the view of the memory is unified but it has a cost. You may use AFFINITY in OpenMP following is a good ans simple understanding for that : http://www.glennklockwood.com/comp/affinity.php

    Sincerely.

    Pierre Léonard

  • Do you routiunely close the peritoneum over pelvis after abdominoperineal resection for rectal cancer?

    I just started with laparoscopic abdominoperineal resections for low rectal cancer. There was a patient with rectal cancer on 1 cm, without neoadjuvant therapy. It was a thin man, and operation went smoothly. I put some sutures on peritoneum to close the pelvis, like in open procedure. But after operation patient went in ileus and I had to operate him again (laparoscopicaly) on day 8 and found cca 30cm of terminal ileum in pelvis, which slipped between sutures. Bowel was vital but affected, no perforation, no peritonitis. I closed the pelvis with dual mesh. After two days patient became more and more septic and our team decided to make laparotomy and we found diffuse peritonitis with fibrin and pus everywhere. The mesh was in situ, there was no bowel perforation. We performed only lavage and treated the abdomen with negative pressure. After two sessions we managed to close the abdomen, and the patient is now OK.

    How do you act in APR? Do you close the peritoneum over pelvis or leave it open?

    Kamal Eddin Bani-Hani · Hashemite University

    Dear All,

    Wishing all of you a Merry Christmas & A Happy New Year

  • how to compute expected PCO2 in chronic metabolic acidosis ?
    Using Winters' formula ? Delta CO2 =1.2 × Delta HCO3 ? Other formulas ?
    Marco Marano · Maria Rosaria Clinic Pompeii Italy

    Please, attached you find a letter (in english language too) summarizing my opinion on the use of Winters' formula. it runs well only if HCO3< 10-12 mmHg.

    A full paper on this topic is under revision by a Journal

    I hope it add another piece to the puzzle

  • Liu Sai added an answer in Parameter Estimation:
    What are the parameter estimation techniques for CTMCs?

    Ladies and gentlemen, I wanna know the main articles that describes the most important techniques about parameter estimation for CTMCs. Also, in a few words, what are the most used techniques?
    Thanks in advance.

    Liu Sai · Hunan University

    Sorry, I have not studied in this regard, thank you!

  • Dorota Jarecka added an answer in SciPy:
    Why are physicists stuck with Fortran and not willing to move to Python with NumPy and Scipy?

    Nowadays all of the major Fortran related numerical calculus have exactly mapped equivalent libraries in more modern language framework like Numerical Python (NumPy) and Scientific Python (SciPy). 

    What keeps physicists stuck with Fortran?

    Performance? 

    Portability?

    Scientific evidence?

    Dorota Jarecka · University of Warsaw

    Marek Wojciech Gutowsk: People write papers about fancy functions/scientific schemes and many of them are implemented in Fortan. Using them with full confidence from Fortan might be as hard (harder ?) than using from Python. 

  • Hamed Haghi added an answer in Ultrasonication:
    What is the maximum ultrasound power for nanotubes?and how about the correspondin time?

    There is one belief indicating on shortening of nanotubes under intense ultrasonication. Is there any maximum value for the ultrasound power when we apply sonication by a probe? I could not disperse my nanotubes in water by ultrasound bath which is why I am thinking of using a probe. Actually, I would pretreat nanotubes by acid treatment or the other methods fisrt.

    Hamed Haghi · University of Tehran

    Hello Ms. Raeisi;

    I have already worked with Ultrasonic irradiation in my works both indirect (Ultrasonic Bath; UB) and direct (ultrasound probe; UP) their intensity is not comparable. For UB; power intensity can not be as high as 1-3 W/cm2 but when you use UP; power intensity can be increased significantly 40-50, or over 100-150 W/cm depending model of probe and machine, selected amplitude, diameter of applied probe and so on. Frankly speaking I am not familiar with Nanotube (I have just heard the Name!); but the intensity is not comparable. Keep in mind the vital effect of power intensity (W/cm2 or W/cm3).  Also keep in mind about gradual increasing of ambient temperature by sonication.

    Regards,

    HH 

  • How can I use the reduced-order modeling methods (like proper orthogonal decomposition, Volterra series) to conduct unsteady aerodynamic analysis?

    Recently, I have read some references applying proper orthogonal decomposition to solve unsteady aerodynamic problems. I'm very interested in this topic and really want to learn more about it. For now, I'm not sure how this method works, so, can anyone who is familiar with this topic give me some advice about starting in this field? Or some recommendations for related materials (books and references that may contain necessary mathematics background)? Thanks a lot!

    PS: I'm familiar with linear algebra and basic matrix analysis, but I don't know much about control theory since I majored in aerodynamics.

    Liu Sai · Hunan University

    Sorry, I have not studied in this regard, thank you!

  • Liu Sai added an answer in Liquids:
    Which one of the SAFT EOSs is good for modeling both vapor and liquid phases?

    I do calculations with sPC-SAFT EOS for CO2/H2O system. It performed good for liquid but the results of vapor phase were not good.

    Liu Sai · Hunan University

    Sorry, I have not studied in this regard, thank you!

  • What is the maximum allowable offset for a boundary plane normal where the boundary can still be considered coherent?

    Developing an algorithm which can extract grain boundary types and coherence from atomistic simulations.

  • Salah Eldeen Gasim added an answer in Electrical:
    What will the effect be if I convert 440V AC to pulsating DC on transmission and how will the behaviour of the electrical equipment be ?

    What will be effect if i convert 440V AC to pulsecting DC on transimssion and how will be the behaviour of electrical equipment ?

    Salah Eldeen Gasim · Sudan University of Science and Technology

    Great thanks Prof. Biswas for the knowledge you share .. Your interaction and support by sharing your knowledge with the following generations is highly appreciated.

  • Pierre Leonard added an answer in Linux:
    Could someone explain more about cache-misses event of Linux perf?

    Hi all,

    As you know, Linux perf is a tool by which you can read performance counters of CPU. I executed a single-thread application on Intel Core 2 Duo. The application consists of a long int array that its size is 260000 elements. Thus, if block size is considered 64 bytes, more than 32000 LLC misses should be occurred (260000*8/64). But, number of counted misses by cache-misses event is about 7000. Could you tell me why number of counted of LLC misses is much less than cold misses assessed by Linux Perf. tool?

    Suppose "t" is the single-threaded application which I mentions before:

    >>sudo perf stat -r 500 -e cache-misses ./t
    Performance counter stats for './t' (500 runs):

    7,507 cache-misses ( +- 0.68% )

    0.004473342 seconds time elapsed ( +- 0.77% )

    Regards,

    Pierre Leonard · French National Institute for Agricultural Research

    Hi Kamid,

    The linux kernel man aged a global cache for files and virtual memory as the files are mapped in the virtual memory of the process-us states.

    My opinion is that you have to take care and produces time execution in the different states :

    • first Reading include the time to get the data in memory ;
    • the second reading can be in e  the memory cache, of your computer. That depend ad of the size of your ddr3 memory size and  your file size.  Meaning if the file size in lower of your memory size the second reading will  always be in the memory cache. ;
    • If the size of the data read and written is higher of your memory size you will have many update modification gezt-in  and get-out  in your virtual memory, and the first data read will be r-read from the origin with the time need for that ;

    So for your test that need a lot of writing , before do a sync. some time ir will take 15secondes. that could be important.

    In your test do ,parallele R/W to have a system lower, but a better cache working efficiency. and may be a good result..

    Sincerely.

    Pierre Léonard

  • Handol Lee asked a question in Gold Colloid:
    Does zeta potential value vary with colloid size in the same solution?

    If there are two different sizes of colloids (10 nm and 1 um) in the same solution (the same conditions such as the same pH, etc),  the 10-nm colloid and 1-um colloid have the same zeta potential?

    Simply say, in one solution(DI-water) + two different sizes gold particles, the gold colloids have different zeta potential values due to the size difference? 

  • Change of the orientation of substrate using C-Interpreter in Silvaco-TCAD ?

    Any one please know how exactely we can change the orientation of substrate using C-Interpreter in Silvaco-TCAD ? Thank you!

  • Has anyone attempted to quantify learned net avoidance in fish?

    I am interest if anyone has attempted to quantify, or has any evidence that fish can become accustomed to nets and 'learn' to avoid capture when sampling is undertaken at high temporal resolution (e.g. weekly).  My interest is related to field-based monitoring programs in 'closed' (e.g. river pools, wetlands) or small freshwater systems involving regular, intense sampling programs (e.g. weekly/fortnightly).

    Paul Graeme Close · University of Western Australia

    Hi Dan,  small fyke nets with a single wing - very effective for capturing small bodied fish.

  • Peter J Murray added an answer in Bone Marrow Cells:
    Is the formation of Myeloid derived suppressor cells a two signal or one signal procession?

    As DI Gabrilovich reviewed before (Nature Reviews Immunology 9, 162–174), it might be a two signal procession to induce functional MDSC (expansion-activation), now I want to ask if someone has any experience to induce MDSC from mice bone marrow cells which only bearing gr1 cd11b markers but has no immuno-suppressive function? And if we can treat these cells as the first phase of MDSC (expansion but not activation)? Thanks.

    Peter J Murray · St. Jude Children's Research Hospital

    The answers to your questions are in the Haverkamp et al. Immunity paper (with the references). In a nutshell, there is no such thing as a defined MDSC - only collections of myeloid cells that gain maturity at the inflammatory site (or in vitro through the action of T cells)

  • Hamed Haghi added an answer in Flotation:
    How calcite and silica can be depress in froth flotation of fluorite?

    How calcite and silica can be depress in froth flotation of fluorite? I have already tried sodium silicate and quebracho.

    Hamed Haghi · University of Tehran

    Hello dear Sir;

    When you are involved in flotation of Flourite (Fluorspar; CaF2); you should take care about following items from my point of view:
    1- Conditioning temperature; ambient temperature has a vital effect on conditioning procedure of Fluorspar flotation; therefore I think if you use Oleic Acid and Sodium Carbonate (Na2Co3) (or mixing with Sodium Silicate??) in hot ambient temperature you can separate Fluorspar from Quartz. Please keep in mind about pH of conditioning. Solubility of Oleic Acid in higher temperature and basic pH is increased therefore its performance as collector for floatation is more selective and better. Please keep in mind that in this flotation system sometimes you can handle the test in 50 centigrade degrees temperature or higher in some case near 80 centigrade degrees.
    2- Have you ever used mixture of Oleic Acid (OA) (or other fatty acids) with sulfonates (such as Cytec Aero 825) as auxiliary collectors? For example mixture of O.A (80%) and Aero 825 (20%)? In this case selectivity of collector in flotation of Fluorspar especially in presence of Calcite can be improved.
    3- For depressing of calcite and dolomite (using Quebracho) could be useful; and for Quartz normally Starch and Dextrin could be useful.
    4- Therefore finally I advise you following reagents:
    - Oleic Acid as collector & Aero 825 as auxiliary collector
    - Sodium Silicate and sodium carbonate as pH modifying; sodium silicate can be good dispersing and depressing agent (be careful about dosage; but I prefer this reagent) I advise pH: 8-9 for basic tests! Quebracho for depressing Calcite and Dolomite and Starch & Dextrin for depressing of Quartz and Iron oxides minerals.
    5-By increasing temperature I believe grade and recovery of Fluorspar can be improved significantly; while fluctuation of pH probably will be increased.
    I think you should handle some trial tests in order to monitor responses of your sample to combinations, sequences of conditioning time and reagent dosage.
    I believe monitoring pH and temperature and synergism effect of reagents has vital effect on results of your flotation tests.


    I hope this information could be useful for you.
    Regards,
    HH

  • Mireille Kameni added an answer in Androgens:
    How could an androgenic treatment affect the creatinine level of animals treated?

    I get higher creatinine serum levels in the treated groups receiving the androgenic compound compared to the control and untreated ones, is there is any explanation for this? Thanks you all

    Mireille Kameni · University of Yaounde I

    thank you zack your answer is exactly the one i expected to justify results i've obtained and the articles comes at  right point. thank you

  • Vitaly Voloshin added an answer in Graphs:
    How graph union has more effect if there is a change in smaller graph? Could any one explain it with set theory example?

    Please Relate the set theory to graph theory.

    Vitaly Voloshin · Troy University

    James provides an excellent example.  I could extend it. The chromatic polynomial of the union of two graphs is the product of the chromatic polynomials of the components.   So, a change in the smaller graph is like a change in one factor in the product. Chromatic polynomial gives the number of proper colorings; each coloring generates a partition of the vertex set into stable (also called independent) subsets.

  • How does the implementation of a low temperature regime (60/30 or lower) affect heat source in district heating?

    What might be necessary investments in the heat source to adapt it to low temperature regime?

    Maddali V S Murali Krishna · Chaitanya Bharathi Institute of Technology

    This information may be useful for your research

    DH is a cheaper and more efficient technology for high heat density areas, such as cities. While onthe other hand, heat pumps result more beneficial in lower heat density areas, as rural areas .

    Case studies;Belgium does not count with supporting measures for DH neither at national nor at regional level.However, some cities are taking the lead in finding the way to create and promote the heat marketin their jurisdiction while some regional initiatives have been taken to support green heatgeneration. This will, hopefully, set the example and provide the framework for the general energy planning of the region, or preferably, the country.

    Ref:Market model heating networks: Benchmark of DH markets in Sweden, Denmark, and Belgium

    www.stepupsmartcities.eu/.../Flanders%20district%20heating%20updates

  • Have I found a new way to the concept of DERIVATIVE?

    Given an algebraic system based on polarities on the sphere. A pair of opposite points and their equator constitute a basic element. (Add the equator to Riemann's unification of opposite points in elliptic geometry.) Two elements determine a resulting element of the same set. This is a partial binary operation with two axioms: ab = ba; (ab)(ac) = a. I call any set of this type a projective sphere. (Cf. Baer's finite projective planes and Devidé's plane pre-projective geometries.) From these axioms a number of important properties can be deduced. For example, if the set has at least two elements a and b, then xx cannot be properly defined for the whole set, because (ab)(ab)=a=(ba)(ba)=b contradiction. This means that in the general case xx must remain undefined, as with the case of division by zero in fields. However, if a smooth curve is given on the sphere, or an oval in a finite set, then the xx operation CAN partially be defined for the elements of the curve or of the oval as the tangent to the given point. Example: given the oval of the four reflexive (self-conjugated) elements in a 13-element finite sphere; the derivative consists of the same four elements. Another example: Given the basic elements on the sphere with homogeneous coordinates. Take the circle with center (1,0,0) and radius pi/4, given by elements (1,√(1-c^2 ),c); its derivative is the curve given by elements (-1,√(1-c^2 ),c). In this interpretation, the derivative does not represent the number indicating the slope of a straight line, but a set of the same type of geometric objects out of which the original curve is made. Also, this gives that every smooth curve evokes a geometry of its own, defined specifically for the given curve.

    István Lénárt · Eötvös Loránd University

    Dear Friends, thanks for encouraging comments from different corners of the round world... As I tried to expand in another conversation on center of mass of a spherical triangle, my approach to these questions comes from my four-decade-long experience in drawing and constructing on spherical surfaces. This experience makes certain geometric concepts more "natural" for me than for those without such background. Besides, my abilities, if any, enable me to invent basic ideas rather than elaborate their connection to past results. Lack of relevant knowledge is also a hindrance in several cases. However, extension of a concept to unexpected areas is a real challenge, and I will try to legalize, so to speak, the extension of "derivative" as referred to above. Merry Christmas and enjoyable research to all of you!

  • Sethu Saveda Suvanam added an answer in Band Gap:
    What is the relationship between a material color and its band-gap? How can we estimate the band-gap by color?

    What is the relationship between a material color and its band-gap? How can we estimate band-gap by color?

    Sethu Saveda Suvanam · KTH Royal Institute of Technology

    I agree with both Dr. Ravi and Tsvetanka that it may not be possible to estimate the bandgap by the colour of the material. And one such example is SiO2 on Si which has a thickness dependence as mentioned above.

  • Is Normality of data necessary for regression analysis?

    I am wondering is it really necessary to have normally distributed data for Enter or stepwise regression? Also if its not normally distributed than do we have to transform it before running regression? 

    Elmer Villanueva · Xi'an Jiaotong-Liverpool University

    I'm assuming that you're talking about LINEAR regression here.

    Formally, linear regression does not assume that the data (by themselves) need to be normally distributed. Rather is assumes that the errors need to be normally distributed. In practice, run a linear regression and plot the line of best fit. Then, we look to see if the scatter of points about this line is normally distributed. It seems strange that in order to test whether linear regression is a good model to run is to run linear regression, but there you go.

    This is what you do in practical terms: 

    1. Regress your dependent variable on your independent variable(s) using your favourite statistics program.

    2. Ask your program to produce residuals.

    3. Check the distribution of the residuals using visual means (eg., normal quantile plots, normal probability plots, kernel density, etc.) or more formal tests (eg., Shapiro-Wilks, Kolmogorov-Smirnov, etc.).

    If you find that there are violations to this assumption, then this may derive from a number of issues, such as

    0. There are errors in the data such that a small subset of observations have large errors. This should have been picked up during the cleaning step.

    1. The distributions of your dependent or independent variables are significantly non-normal. To be fair, if this is the case, it should come as no surprise because it would have been uncovered during exploratory data analysis.

    2. A straight line may not be the best fit to the data. That is, the assumption of linearity is violated. You may want to try using non-linear regression models.

    3. Your data may be composed of distinct subsets that require you to approach it more subtly, because you need to distinguish between or among the subgroups and fit individual regressions to each one.

    Anyway, these are just a few thoughts early on Christmas morning.

    Good luck!

  • What is and how the psyche works?

    While this is not a question, in 'PSYCHE - Structure and Function', there are many answers to questions that are commonly made in RG.

    Dear friends,

    It is my proud to present to you the first translation of PSYCHE. A hard work, that surely suffers from many imperfections, but has the sole purpose to get my ideas reaching to the large scientific community where English is current language. Beyond the errors, of which I am fully responsible, I have tried to communicate my theory in a simple way, including changing some text in Spanish, to have any chance of being discussed at other levels.
    I want to thank you for allowing me to share with you this achievement, and take the opportunity to wish you a Merry Christmas in the company of their own, and hope that all your expectations are met in the coming year.

    An affectionate hug, Dante.

    PD. The text is available on RG

  • Can anyone give me any advice about which parameters of operation I have to take into account to select a steam turbine?

    I mean, properties like temperatures, enthalpies, pressures or manufacturers are needed? I really appreciate any advice.

    Maddali V S Murali Krishna · Chaitanya Bharathi Institute of Technology

    The following information may be useful for your research

    1) Range of power in MW

    www.energy.siemens.com/hq/en/fossil-power-generation/steam-turbines/

    2) Type of the turbine like Back Pressure Controlled Extraction,Back Pressure Un-controlled Extraction,Straight Backpressure,Controlled Extraction Condensing,Straight Condensing with bleed  and ,Straight Condensing

    www.triveniturbines.com/en/products/...turbine/selection-criteria.html

    3) Pressure and temperature of main steam

    4) Tempeature range of reheat steam

    5)Details of Exhaust areas 

    www.energy.siemens.com/hq/en/fossil-power-generation/steam-turbines/

    6) Type of energy available that is imulse turbine or reaction turbine

    7) Type of compounding adopted that is pressure compounding, velosity compounding and pressure-velosity compouning

    You can also refer

    Power generation hand book; Selection and hand book

    accessengineeringlibrary.com/.../power-generation-handbook-selection-

  • What is your next step when you have a patient with an incomplete colonoscopy in the absence of large intestine stenosis?

    Considering that all the conditions for the test are fine.

    Kamal Eddin Bani-Hani · Hashemite University

    Dear All,

    Wishing all of you a Merry Christmas & A Happy New Year

  • Is there such a phenomenon as non-contact sport?

    In the literature it is quite common to see references to non-contact injuries eg anterior cruciate ligament strains/ruptures. Contact often occurs between athletes contest for or retaining possession of the ball say soccer, but are there other  factors involved?

  • B.A. Padder added an answer in Agarose Gel:
    What is the best gel to detect small dna fragment?below 250bp?

    Im doing DNA digestion and using 3% agarose gel in my experiment . Failed to get any band .Any suggestion or recommendation of what type of gel best use to detect small dna fragment?thank you very much

    B.A. Padder · Sher-e-Kashmir University of Agricultural Sciences and Technology

    Since you are digesting the DNA I will suggest you to use PAGE (6%) to resolve your fragments. If fund is available then go for metaphor agsrose and use it at 3% as such or you can combine sgarose with it At a ratio of 2:1.

  • Can I combine waves of the ELSA to look at different cognitive measures that are not asked on each wave ?

    I want to use some of the cognitive measures from the English Longitudinal Study of Ageing but many of the measures I want too look at (e.g. self reported memory) are not asked in wave 6 they are only asked in earlier waves . As I want to look at wave 6 to give the most up to date cross section, but doing so will limit me to looking at the 3 cognitive measures that were asked, I want to know is there any way I can use the self report scores from the older waves of the ELSA? or is the fact that they're data from older waves going to create too much noise? Any help or insight would be really appreciated, many thanks

    Henare Broughton · Trinity College Dublin

    I have no expertise in that area however you may wish to undertake a longitudinal study. If you do that you can compare your data from the extant literature on ageing.

  • Jason W. Moore added an answer in Geography:
    Is the anomalous status of geography helpful for the geographers in their professional field?

    Geography is not science. Nor it is an art. Geography is science and arts both. Some time I personally see it nowhere. Is it wrong justification for the discipline or discrimination in the classification of knowledge??

    Jason W. Moore · Binghamton University

    At its best, geography speaks to the potential for transcending the Two Cultures -- of the "natural" and "human" sciences -- and allows for the development of knowledges that understand humanity in the web of life. This is the thrust of world-ecology and other perspectives clustered around space, nature, and power -- and their constitutive inter-relations.