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  • Abdul aziz Jaafar added an answer in Abaqus:
    What are the difference constitutive models available for bone which can be directly used in abaqus ?

    Currently most of the material models available for bone are linear elastic with E nd v. Are there any better models available for representing bone in Abaqus like concrete damage plasticity etc.

    Do all bones have same material properties or are these very site specific.

    Abdul aziz Jaafar

    Dear Visky

    Most of bone is difficult to break.. and linear elastic material model may be suitable.. havent heard  any bone behave like rubber.. If there is that kind of bone.. hyperelastic material model may be suitable...   What kind of bone that you are looking at and when you find the bone depart from the behaviour of linear elastic material


  • Prashant Sahu asked a question in Software Programming:
    How to make a low cost switching device ?

    I have a high-precision single DC source, with which I want to power 4 external devices/circuits in a (software) programmed fashion asynchronously (ofcourse, one-by-one). The switching circuit/device must not change the current (or introduce noise) too much while giving/switching power to those 4 external devices. Please suggest a low cost solution. I am not looking for professional Swithcing cards available commercially.

    Thanks and Regards,

  • Tarik Ömer Oğurtani added an answer in Metallic Glasses:
    Why fracture angle of metallic glass wire is different with different size?

    Recently, i have did tension test of metallic glass wires with two different samples.  the fracture angle of different size metallic glass wire is different like 

    the fracture angle of 130mm metallic glass wire is 48 where as the fracture angle of 136mm metallic glass wire is 51 why

    Tarik Ömer Oğurtani

    Dear Ishtıaq finally I found a very compheresive article written by ZF Zhang J. Eckert and Schultz in Acta Mat. 51, (2003) 1167-1179, where difference in compressive and tensile fracture mechanism of Zr59Cu20Al10 Ni8 Ti3  bulk metallic glas was investigated. In the discussion section these authors mentioned that '' The shapes of the two kinds of specimens might affect the critical shear fracture stresses of the metallic glass calculated from the measured fracture angles and the known fracture stresses for both compression and tension.'' They had found 54o for compression where 3 mm dimater wire was  used, and 43o for tension in connection with test piece of  6mm x 3 mm x 1.5 mm specimen was employed.''  They found the following the critical facture stresses such as:  0.8 GPa for compression and 1.1 GPa for tensile specimens Where the applied fractures were  1.69 GPa and 1.58 GPa, respectively.

    Best Regards

  • Gordon Böer added an answer in Imaging Software:
    Any one can suggest medical imaging softwares?

    Can anyone suggest medical imaging softwares that deal with the medical imaging formats. 

    Gordon Böer

    A popular free framework for medical image processing is ITK often in combination with VTK. In general it is a C++ library but Python wrappers are also available.

    A graphical environment which is mainly build upon ITK/VTK is called MevisLab.

    See the attached links für more details.

    + 2 more attachments

  • Shankar Subramanian added an answer in Molecular Diagnostics:
    Is it possible to calculate the force constant for a molecule ?

    Usually we calculate the force constants for bond length, bond angle and dihedral angle. I want to calculate the force constant for entire molecule.

    Shankar Subramanian

    Dear Chandrashekar,

    I am a medical Doctor and not an expert in this field. But your question was interesting and I am attempting to answer the same.

    Force constant of a bond is a reflection of its bond strength. It takes more strength to stretch a bond and break it than to bend it. Lots of paper out there that have calculated force constants of a bond between 2 atoms.

    In a molecule has n bonds, then most papers seem to say that the total force constant is not simple addition of each of the bonds. There is some variation on which many people have made models.

    So, the answer to your question might be this. Yes, you can figure out the force constant for a molecule if you know the force constant for each individual bond. Simple addition might give you a rough idea but you will need a bit more complex modeling than just addition.

    I am attaching a couple of references

    a. D.Michael Byler, Heino Susi, William C. Damert. Relation between force constant and bond length for carbon—nitrogen bonds. Spectrochimica Acta Part A: Molecular Spectroscopy Volume 43, Issue 6, 1987, Pages 861–863

    b. attached as an article

    Hope it has helped in some way.


  • Park Bokuk asked a question in Intersectionality:
    My application predicts only positive class. How to calculate precision recall?


    I want to know how to determine the precision and recall or sensitivity and specificity.

    My application predicts only location of intersections on the road. So, there are no negative predictions such as FN and True negative (predicted condition is negative and the condition is true) since my application only predicts intersections.

    In this case, how to evaluate the performance of my application?

    TP : predicted intersection and it is true.
    TN : predicted intersection and it is false.
    FN : predicted there's no intersection and it is false.
    FP : predicted there's no intersection and it is true.


  • Karl-Heinz Enderle added an answer in Evaporation:
    How do I use evaporation and condensation model using CFX?
    • I am facing problem in vapor fraction conversion in evaporation and condensation in solar still. How use evaporation and condensation model for my solar still problem?
    Karl-Heinz Enderle

    for calculation of Saturation pressure in dependency of the temperature have a look on http://cires1.colorado.edu/~voemel/vp.html. Hope this is a bit helpful.

  • Ariel Turcios added an answer in Water Sampling:
    Why HNO3 should be added in waste water sample before heavy metal determination by AAS?

    Few drops of HNO3 are added in waste water sample before heavy metal determination by AAS. Why it should be added? If not, what problem might be arised?

    Ariel Turcios

    In addition to maintaining a low pH (for reasons already mentioned in previous answers), nitric acid is used and no sulfuric acid for example or other acid, because nitric acid only contains H, O and N and these elements are not quantified.

  • Anil Kumar added an answer in Conventional PCR:
    Why Taq enzyme cannot be stored at room temperature ?

    During PCR reaction temperature will be high as 90oC. But it is usual practice to store Taq at freezing temperatures. Why it is done so ? Why we cant store it at room temperature ?

    Anil Kumar

    At room temperature the efficiency of enzyme will decrease and it will be not useful for long term. but if we store it in refrigerated condition, then we can use it for long time.

  • Huei-Yu Chou added an answer in Polypyrrole:
    How to electrodeposit graphene oxide polymer o electrode?

    polymers like polypyrrole...I need a detailed procedure ...most of articles do not explain in detail I would be thankful if you coud advise me on some thesis about the subject. 

    graphene oxide/polypyrrole electrodeposition

    Huei-Yu Chou

    Pyrrole needs to be an ionic solution before conducting an electrochemical deposition because it belongs to a neutral molecular instead of cation or anion.  In my lab, We didn't use polypyrrole due to its huge weight of molecules, which may not be dragged easily under electrodeposition.   You may add few iron chloride into an electrodeposition bath to dissociate pyrrole. You can find out the condition of electrochemical deposition (ECD) by linear scanning Voltammetry. Hope these helpful.

  • Mirabbos Hojamberdiev added an answer in Halogens:
    Can someone offer CIGS data exchange for the reference in the article?

    Dear colleagues, I am not able to produce and analyse CIGS cells at the place where I work now. I can only measure IV characteristics of my sells. Provide me data on spectral response of your CIGS cells, I want to compare the light energy, halogen and CIGS to simulate how much energy will be “missed” if I use the halogen lamp. I will mention in my publication that I received the data from you.

    Mirabbos Hojamberdiev

    Assalomu alaykum Asliddin aka, mani emailmga hat yozvoring, kegin sizni emailiyzga maqolani jonatvoraman. Mani emailim: hmirabbos@gmail.com

  • Vijay Renigunta added an answer in CRISPR/Cas:
    I am trying to use CRISPR/cas to create a genetic mutant but have never used this system before; how do I design and clone my gRNAs?

    I have never used CRISPR before and I am stuck on the first step! How do I design my gRNAs? Do i need to make primers for my gRNA or just use the complementary sequence to my target sequence?

    Vijay Renigunta

    Genscript  can generate or custom make plasmids ( only for wt cas9) for the desired gene from their Genome-wide gRNA database based on Sanjana et al 2014. Its relatively cheap and mostly works ( approx 200 $). Click the link below


  • Laura O'Connor added an answer in Med:
    What should be the appropriate statistical test to conduct if investigating dietary intake and Mediterranean diet intake of a cohort using FFQ?

    I used the EPIC FFQ to collect data on food intake. FETA software was then used for nutrient analysis and food group analysis. I also used the 14 - item med diet short screener to collect data on med diet intake. I am trying to find out if their reported dietary intake is consistent with reported med dietary pattern.

    Laura O'Connor

    For the statistics I think you should use measurement of agreement statistics for example bland-altman graphs or Kappa measurement of agreement for categorisation. As to whether you use the nutrient or the food group output if you are matching to a scoring system (which you should) then it will call for the food group output as most of the systems use intakes of  vegetables, fruits and nuts, legumes, unprocessed cereals, meat and meat products and  dairy products or some variation of this to characterise the Mediterranean diet.

  • Kleomenis Kalogeropoulos added an answer in SWAT model:
    Which method do you recommend for estimating the daily percipitation missing data with a continous range of gaps?

    Dear Researchers,

    I am working on a rainfall-runoff model which needs daily percipitation namely SWAT model.

    I run my model using observed precipitation data and the missing data were filled SWAT automated statistical method called but I didn't get the good result in the calibration. I also tried Multiple imputation method using SPSS but the results weren't acceptable while the data gaps are sometimes contionous for one or more years. You can see the percipitation analysis data in the attachment.

    As the input quality especially precipitation has an undeniable effect on model output I am looking for an efficient and reliable method to estimate the missing data. As the rainfall-runoff model is just a part of my thesis, the model development time is an important factor for me as same as accuracy.

    I have found a wide range of methods such as singular spectrum analysis, modified multi- linear regression, improved weighting methods, geostatistical approaches (conventional centroid method or voronoi tesselation) and so on.

    It can be mentioned that I am working on river  watershed scale which is totally 22000 km2.

    I gathered data for simulated rainfall data (Climate Research Unit (CRU) rainfall dataset, 12 stations ) and the observed dataset (32 stations) as my available dataset options. As I tested the SWAT model with various precipitation dataset alternatives the results shows that the model works better when I gave it the simulated and observed stations all together. So I am looking for a suitable method to improve the quality of observed ones.

    I would appreciate if you consult me which efficient method you recommend in this case.

    Best Regards,


    Kleomenis Kalogeropoulos

    Also you can create an artificial statistic weather station in order to use it in SWAT model by modifying SWAT database

  • Wazeera Abdullah asked a question in Rhizoctonia:
    What is good way for culture rhizoctoniafrom root tissue?

    I tried to culture root tissue of orchid plant to get rhizoctonia fungi from it, but it not successfull.

  • Bramhaiah Kommula asked a question in ZnO:
    How to prepare sampling for ICP OES measurement, i have Ag and ZnO on carbon film?

    i have a sample, which is containing Ag, ZnO on carbon film. how to make sampling for ICP OES measurement.

  • Tudor-Cristian Stan added an answer in Abaqus:
    How do I apply end moments to an I beam modelled with shell elements in Abaqus?

    I am modelling a simply supported I beam in Abaqus using shell elements and I am considering a load case with end moments. I would like to apply an end moment as accurately as possible. Until now, I have applied shell edge loads (with a linear distribution along the web), which worked quite well. It is not entirely valid however once the distribution of stresses is no longer elastic. I have also tried applying a bending moment or rotation, using kinematic and distributing coupling, with a reference point outside the beam, but without success. At the moment, I am appying a displacement with a linear distribution along the height of the beam (similar to the stress distribution mentioned earlier), but I was wondering if anybody would have a more accurate / simple idea.

    Tudor-Cristian Stan

    Hi Mohsen!

    Thanks so much for your reply. I used a distributing coupling constraint as you suggested and it seems to work perfectly. I Applied the boundary conditions to the master node, along with the loads (bending moment and axial force) and the results seem accurate.

  • Ken Alexander Penaso Bautro asked a question in Glycemic Index:
    Do you have a copy of this article, "Slowly Digestible Starch: Concept, Mechanism, and Proposed Extended Glycemic Index"?


    Critical Reviews in Food Science and Nutrition

    Volume 49, Issue 10, 2009

    Genyi Zhang & Bruce R. Hamaker
    pages 852-867
    Publishing models and article dates explained
    Published online: 02 Dec 2009

    :: I can't access it for free. Thanks ahead for your generosity! 

  • José Avila-Peltroche added an answer in Microalgae:
    What would be the best method for harvesting microalgae culture?

    I have worked with microalgae recently and centrifugation was the best way to harvest the culture. However, it is known to be a costly process and very lengthy one, but suitable for lab-scale (still depends on culture volume and the centrifuge itself). What would be the most cost effective and rapid method for harvesting microalgae cells?

    Any suggestion would be much appreciated!

    José Avila-Peltroche

    Why don't you try immobilization techniques?

  • Ramnath Takiar added an answer in Quantitative Methods:
    Could anyone please help me in VIC model calibration for hilly basin?

    I am trying to calibrate VIC model (0.25 degree resolution)  for KOSI basin in India, but my model results is below the observed value by 1500 cumecs throughout the year even though the model could predict the peak. I had already tried with VIC and routing parameters which could only increase stream flow values by a maximum of 100 cumecs. Can anybody give suggestions to improve the result.

    Data sets used: IMD Scheffield forcing data

    Observed Data at Chatara gauge point from ICIMOD

    Thanks in advance

    Ramnath Takiar

    The model fitted may not be a good model. Hence, it is giving consistently low values as compared to observed values. Going by your statement, if the model if giving consistently low values by 1500 cumecs, probably a correction of 1500 to your model value may do the trick. 

  • Constantin D Athanassas added an answer in Radioactivity:
    Are there any known rocks with negligible radioactivity?

    Which chemogenic or clastic deposits (type and locality) would have the most negligible -practically zero-radioactivity? I would expect halite and gypsum to have very low radioactivity, if they are pure (no clay or detrital minerals). With the same restriction, sandstones (quartzite) should do it too? Are there any known deposits with almost zero radioactivity?

    Constantin D Athanassas

    Thank you, Ludo. I will note down this piece of information.

  • Mansoor Siyal asked a question in Attachment:
    What's the problem with the model attached below??

    Hi everyone..
    Anyone please help me with the model (figure attached below), why i can't connect the sequence analyzer(phasor) there at that point.? 

  • Serge V. Shil’ko added an answer in Heat Treatment:
    Any possible condition to improve the fatigue strength of Al 6063 by using Age Hardening (heat treatment)?

    I doing project of improve the fatigue strength of Al 6063 using by age hardening.

    Serge V. Shil’ko

    One method of improving of fatigue strength presumes age hardening as a prolong insolation of issiues by temperature 250-300° С. This heat treatment reduces the distortion of crystal lattice and promote to coagulation of secondary phases which forming after desintegration of solid solution. These processes allow us to reduce residul stresses and to improve plasticity of issues. 

  • Paola Di Bonito added an answer in Trypsin:
    How can I trypsinize sHela?

    I have two questions, I am trying to trypsinize my sHela with trypsin 2 ml for 5 minutes in the incubator, then after checking the percentage of detaching cells under the microscope, It is always low as 30% or less, so how to do a perfect trypsinization to get as much cells. Second question, If I am incubating several 10-cm culture plates, can I put them over each other, like 4 plates over each other, I am afraid they get suffocated

    thanks in advance

    Paola Di Bonito

    FBS contains trypsin inhibitors, use to wash with PBS Ca++ and Mg++ free or medium w/o serum your cell monolayer  before trypsin treatment. 

  • Arno Gorgels added an answer in Foundations of Physics:
    Do you agree with Stephen Hawking's recent conclusion that black holes don't exist?
    Black holes don't exist. I published this many years ago. Cantor's Universe doesn't allow the concept.

    Stephen Hawking now came up with the same conclusion. Read: http://www.spektrum.de/news/es-gibt-keine-schwarzen-loecher/1222059

    In my opinion he is right this time. What is your opinion? Was he right then or is he correct now?
    Arno Gorgels

    Well, dear downvoter who probably had no answer to my question above other than Higgs,... in algebraic physics, gravity (not-magnetic attraction of particles) is the outer cohesion of quanta based upon their origin within the well-ordered original space. Kindly, dear down voter, leave the twentieth century and start thinking in spaces. 

    Btw, dear Victor, I don't see your elaboration other than highly speculative. Why? Imho the space of each galaxy extends to the whole of the universe. 

  • Julieth Vanessa Prieto Sandoval asked a question in Development Models:
    What is the difference between "Circular Economy" and "Eco-industry" o the " eco-industrial development model"?

    What is the difference between "Circular Economy" and "Eco-industry" o the " eco-industrial development model"? Taking into account that both concepts are linked with close the loop in the economy.

    Thanks for your time!

  • Francesco Elia Marino added an answer in Urology:
    Testicular cancer: risk age 18-39. Any explanation?
    I recently gave a talk on testicular cancer, and I received a very interesting question about the risk age. We don't actually know why testicular cancer affects, mostly young men. In the literature, there is not a main hypothesis about that. I am asking this question to an experienced researcher in this field. Do you have any possible explanation or hypothesis?
    Francesco Elia Marino

    That could be because of the young age, and because smoking is marijuana is more common in young people.......maybe?

  • Soumya Ghosh asked a question in Wave Energy:
    Parameter data required for wave energy converter?

    Instead of "Following are my parameters requirement" write
    "The data or source of data for the following parameters are urgently required:
    Parameter Name:
    1. Number of WEC
    2. Distance between WEC
    3. Wave incidence direction
    4. Array layout
    5. Length of cable connecting to shore
    6. Buoy Diameter
    7. Rated power
    8. Plant size
    9. Efficiency of storage
    10. Converter efficiency
    11. Unit Cost
    12. Operating & Maintenance cost
    13. Capital cost
    14. Generating cost
    15. Rate of Energy charge per unit
    16. Pre-installation cost

    Your contributions in this regard will be highly acknowledged."

  • Hadil Kathom added an answer in Maternal Phenylketonuria:
    How long might a child with maternal PKU have elevated Phe?
    A child with maternal PKU, with detected only one mutation, is following a standard PKU diet because of elevated levels of PKU. The clinical presentation is the same as in PKU and still the child is a carrier of one mutation only.
    Hadil Kathom

    We made standard sequencing of the PAH gene and we found only one mutation. He has maternal PKU syndrome plus he presents biochemical changes as a classical PKU patient. He is 3y 6mo old now.