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  • Hamid Arabzadeh added an answer in Abaqus:
    How to connect a steel plate(used to transfer the bearing stress,no contribution to strength) to concrete in abaqus?

    1.A steel plate is used to distribute the load evenly to concrete, how to connect the plate(shell) to concrete(solid )

    2. I have to connect two parts (both solid and same material)which should behave as one integral unit.I have just assemble them and they are in physical contact, but will that alone lead to load transfer? which connector i should use


    Hamid Arabzadeh · Concordia University Montreal

    If you need a beam which has no contribution in the strength (i.g. moment strength), you can define the material to be non-isotropic and adapt the material properties in the way that some how eliminate the moment strength. However, if you define the steel part a bit small in the longitudinal direction of the beam, it's contribution in moment strength is negligible. 

  • Yvan Dutil added an answer in Spacecraft:
    Is there any public domain code from spacecraft star trackers?

    I'm looking for star tracker code (not just descriptions) that is mature and has been proven in space, to evaluate and compare performances for far-future interstellar probe missions.   In the interstellar void, parallax causes shifts in the observed inter-stellar angles as the transit progresses. That alters the optimal stellar database that the tracker should use from one position to the next.  So the ability to load or calculate new celestial maps would be needed for an evaluation.

    Yvan Dutil · Télé-université

    I agree. And if you plan an interstellar mission, you need to take account of stellar proper motion.

  • Odilza Lines de Almeida added an answer in Content Analysis:
    How should I select the meaning unit in Q.C.A correctly?

    Below is a segment of Satu Elo et al. article (Qualitative Content Analysis: A Focus on Trustworthiness) :

    It is important to fully describe the meaning unit when reporting the analysis process so that readers can evaluate the trustworthiness of the analysis (Graneheim & Lundman, 2004). However, in previous scientific articles,
    the unit of analysis has often been inadequately described,making it difficult to evaluate how successful was the meaning unit used (Kyngäs et al., 2011).

    Odilza Lines de Almeida · Universidade Estadual do Sudoeste da Bahia

    You should describe in details the units you use and how you built them. Moreover, these units should easily identifiable in your data. I suggest that you pay atention to repeated data as they can be a good unit...

  • Parviz Parvin added an answer in Refractive Index:
    Can you give me a exact equation for calculating the refractive index of a solution with respect to the refractive index of its components?

    I need to calculate the refractive index of a solution like mannose in water. How it depends on the density, temperature and ...

    Parviz Parvin · Amirkabir University of Technology

    Clausius - Mossotti equation is valid as long as no hybrid solution ( NP+ liquid ) is used. The equation  fails in highly scattering media.

  • Yvan Dutil added an answer in Satellite:
    What batteries are used in Pico Satellites ?

    Since ISRO allowing private colleges to launch Pico Satellites (Size: 10cm x 10cm x 10cm, Weight: <1000 Grams), consisting of a bus and payload, how to proceed with the selection of batteries ? The batteries should support 1 watt power and withstand vibration tests in x, y, z axes. 

    Yvan Dutil · Télé-université

    If I remember Surrey team was using standard AA lithium batteries in bundles, but were doing some screening to spot the problematic ones, They had a testing bench just for that.

  • Richard A Durst added an answer in Silver:
    How can I fabricate a Ag/AgCl reference electrode?

    In silver/silver chloride reference electrode, If electrons flow from the copper wire through the silver wire to the electrode AgCl pellet, they convert the AgCl to Ag atoms and the Cl - ions become hydrated and enter the solution. If electrons flow in the reverse direction, Ag atoms in the silver wire that is coated with AgCl give up their electrons (one electron per atom) and combine with Cl –ions that are in the solution to make insoluble AgCl. [http://www.bionanotec.org/Lectures/Membranes/Contents/IBioelectricityIonsinsolution8/ibioelectricityionsinsolution8.htm]. 

    Does it mean that I have to have an unchloridized portion of the silver wire dipped into the chloride solution of the reference electrode so that it can be converted into silver chloride when electron is flowing in the reverse direction? Or I can simply chloridize the whole silver. 

    Assuming it's okay to chloridize the whole silver wire, all the Ag/AgCl reference electrodes I have seen so far have a portion of bare silver without silver chloride coating- what is the function of this portion?

    Richard A Durst · Cornell University

    As I stated in the last sentence of my previous reply, it is not necessary to leave a portion of the Ag uncoated with AgCl. It is fine to coat the entire Ag surface with AgCl.

  • ABDULLAHI Arabi Suleiman asked a question in Drilling Fluids:
    How does iron affect the thermal stability of drilling fluid at down-hole conditions

    1. How does iron affect the thermal stability of drilling fluid at down-hole conditions

    2. I recently carried out XRD analysis of some raw and beneficiated clay samples and discovered that some of the clays ( both raw and beneficiated) contain Laumontite. Could this an additive or naturally occurred with the clays

  • Yvan Dutil added an answer in Earth:
    Can the Hill sphere be demonstrated in laboratory?

    The Hill sphere of the Earth is usually expressed as

           r≈(1-e)a(m/M)3                     (1)

    where M and m are the mass of the Sun and Earth, a and e are the semi-major axis and eccentricity of the orbit of the Earth, respectively. Eq.(1) means that in the radius of r, the Earth dominates the gravity of the Moon. And the Sun only can perturb the Moon with tidal force.

    Theoretically, we can construct a mini solar system according to the Hill sphere. From Eq.(1), the condition to construct a mini solar system on a little height above the surface of the Earth is determined with the mass and radius of a body. Therefore, the density of a material is higher, it is better for making this system.

    The mass of a ball is determined with m=4πr3d/3, where r is the radius of the ball, d is the density of the material to make up of this ball. According to Eq.(1), on a little height above the surface of the Earth, the condition for the Hill sphere of a ball is r3/R3=(4πr3d/3)/3M, where R and M are the radius and mass of the Earth respectively. It is easily calculated that, as the density of the material is larger than 16.55g/cm3, it can be used to make the balls. (Here d0=16.55g/cm3 is called the Hill density.) Because r can be offset, the value of mass of these balls in this system can be free. The densities of Tungsten, Platinum, Iridium and Osmium are 19.3g/ cm3, 21.45 g/ cm3, 22.42 g/ cm3 and 22.57 g/ cm3. Using these materials, a mini solar system could be constructed.

    But, it is noted that, in this artificial system, no small ball can orbit the large one for that the condition for the stable of the orbit is that the small ball is inside 1/2 to 1/3 of the Hill radius. But, this system can be used to test the gravity. It is very helpful to know the gravity.

    Why the Hill sphere has not been tested in laboratory?

    I had a wok based on the Hill sphere. Although it is far removed from current physic, I think, it is often useful. If you are interested, please reference:


    Should you have any comment on it?

    Yvan Dutil · Télé-université

    Interesting idea. However, I would be afraid that residual electric charge or magnetic filed would impair the measurement.

  • Ali Kermani added an answer in Coding:
    Is the run time of genetic programming increased by the increase of the number of data for regression ?

    Actually, I written a GP code for regression in Matlab !! However, due to symbolic nature of the code and the necessity of using time consuming commands like 'eval' for evaluating the fitness of each equation (to replace the input values in the function and evaluation), the run time of the algorithm increased dramatically when using large data sets (e.g. over 2000) !!??

    Is there any survey ???

    Thanks in advance !!

    Ali Kermani · Iran University of Science and Technology

    Dear Iman

    I hope that the below paper would be helpful:

    [1] Li, Zheng, Mark Harman, and Robert M. Hierons. "Search algorithms for regression test case prioritization." Software Engineering, IEEE Transactions on 33.4 (2007): 225-237.


  • Haitham Hmoud Alshibly added an answer in Masculinity:
    Myth or Science “Bald is Better”?

    recent study showed that observers believe a male’s shaved head indicates greater masculinity, dominance, and leadership potential than longer or thinning hair. Thinning hair was perceived as the least powerful look, and other studies have agreed that male-pattern baldness (where some hair remains) is not considered advantageous. Men who have shaved their heads report it can give them a business advantage whether or not it makes them look older (which is debatable). Sources: J. Misener, “Men With Shaved Heads Appear More Dominant, Study Finds,” The Huffington Post (October 1, 2012),But why is this?

    Haitham Hmoud Alshibly · Al-Balqa' Applied University


  • Mohammad Kooti added an answer in Physical Metallurgy:
    Why copper layer plated on a steel substrate in (Ar + H2) atmoshphere changes color from brick red to greyish color while heating to 1000 deg Celsius?

    Heating is done via induction method and particles of copper are also found on the quartz tube inside which sample is kept while heating.

    Mohammad Kooti · Shahid Chamran University of Ahvaz

    As there is no oxygen in the used atmosphere, it is unlikely for copper to be oxidized to any of CuO, Cu2OP, or CuO2. One possibility is that the argon gas is not 100% pure and contains some oxygen and in this case copper will be rapidly converted to CuO. So, before thinking of any other reason make sure that the used gas free of oxygen.

  • Milán Szőri added an answer in VMD:
    How to determine the NMD & VMD of droplets collected on a paper?

    In agricultural spray nozzles, the droplet sizes vary. So how to determine their sizes along with NMD & VMD?

    Milán Szőri · University of Szeged

    If I get you right, one of our paper may give you a direction:  https://www.researchgate.net/publication/24040439_Microscopic_Wetting_of_Mixed_Self-assembled_Monolayers_A_Molecular_Dynamics_Study

  • Yvan Dutil added an answer in Second Harmonic Generation:
    Anyone know of practical way to estimate the optical Second Harmonic Generation and Point Spread function generation by computer simulation?


    I want to estimate the SHG occurence from specific patterned tissues or something. (e.g. striated pattern or crystals)

    Is there any practical ways to done these jobs with computer?


    Yvan Dutil · Télé-université

    It depends of your problem. Astronomer and atmospheric scientist use phase screen and Fourier transform. You might need Monte-Carlo raytracing in your case.

  • Haitham Hmoud Alshibly added an answer in Trust:
    How do you lead people who are physically separated from you and with whom you communicate electronically?

    Today’s managers and employees are increasingly linked by networks rather than geographic proximity.
    3. We propose that online leaders have to think carefully about what actions they want their digital messages to initiate.
    a. They confront unique challenges, the greatest of which appears to be developing and maintaining trust.
    b. Identification-based trust, based on a mutual understanding of each other’s intentions and appreciation of the other’s wants and desires, is particularly difficult to achieve without face-to-face interaction.

    The questions of how do you lead people who are physically separated from you and with whom you communicate electronically? This question needs research.

    Haitham Hmoud Alshibly · Al-Balqa' Applied University

    We tentatively conclude that good leadership skills will soon include the abilities to communicate support, trust, and inspiration through keyboarded words and accurately read emotions in others’ messages.
     In electronic communication, writing skills are likely to become an extension of interpersonal skills.

  • Tom Shaw added an answer in Well Drilling Technology:
    Have anyone attempted to do correlation of cutting data of wells?

    Has anyone attempted to create a database of microscopic images (5x or 10 x) of drill cuttings of prominent formations and tried to correlate within field and then field to field?

    Tom Shaw · LK Energy

    You often have a mud logger on the well site who describes and collect cuttings at specific intervals.  In addition to the cuttings lithology they will also record florescence, mud weight and characteristics, drilling penetration rate, and note any occurrences of hydrocarbons.  It is common to record this information graphically, to facilitate correlation.  After collection, cuttings may be processed for microfossils, geochemistry, and petrology,  If wire line logs have been run, any of the parameters from the mud log can be digitized and collated with the wire line data.  To learn more, search the term "mud logging".

  • Parviz Parvin added an answer in Earthquake Engineering:
    Earthquakes: Is there any reliable technology to predict serious seismic events in advance in order to avoid the disaster?
    Many countries are located on fault lines, where the risk of occurrence is always high. In my homeland Iran we face at least a disastrous earthquake every decade. The last one took place in Bam and that destroyed the whole city with 80000 inhabitant casualties. At least , I remember other catastrophes which happened in Gilan- roodbar and in Tabas during last 30 years. The capital, Tehran, is spread over several fault lines, and it is home to more than 10 million people. We regularly hear the occurrences of such a natural disasters from all over the world, from Japan to Greece, Turkey ,Chili and California -USA.
    After the Fukushima tsunami, the impact of natural disaster on nuclear technology was tremendous and shocked the world. If there was a warning system forecasting the tsunami only 10 days before occurrence, it could hinder the nuclear aspect of catastrophe by early reactor shutdown and could save many vulnerable individuals. Therefore, we come to a resolution that the best way to overcome this vulnerability is to develop our present global technologies pertaining to seismic forecast to hinder or significantly mitigate the forthcoming catastrophes. In the meanwhile, we have published a paper entitled:
    "Novel Techniques for Safer Operation of Present Nuclear Power Plants After Fukushima Disaster", Recent Patents on Mechanical Engineering 01/2013; 6(1):58-74,
    which available on my homepage in RG too. It proposes the hybrid systems to improve the available instruments mainly based on the following facts:
    Radioactive Radon gas surge, surface temperature rise, increase of natural gases - underground effluents and higher level of ultrasonic - acoustic sounds are among the anomalies which occur prior to a severe earthquake. However, a reliable prediction is strongly dependent on the improvement of our present detectors accompanying various lidar techniques and hypersensitive satellite based IR detector arrays as well as the likelihood of complementary advanced techniques and vigorous statistical algorithms. Which physical facts and related technologies do you suggest which may contribute to enhance our abilities in this field?
    Parviz Parvin · Amirkabir University of Technology

    There are many clues to predict seismic activities such as rise of IR local  radiation, Rn surge  and Gases eminent to the atmosphere  using hyper sensitive satellites, remote sensing equipments and lidars as well as in- situ measurements.

  • Ali Kermani added an answer in Histogram:
    Can anyone suggest the approaches for detecting the partial occlusions in the image?

    I just need an idea of how to approach the problem of partial occlusion detection. The images i have are 2d images. I dont have any 3d information, otherwise i would have use depth maps. Full occlusions i have dealt by anlaysing the histogram and gradient approach. But i got stuck here for partial occlusions. Can anyone suggest me some approaches?

    Ali Kermani · Iran University of Science and Technology

    Dear Karlakunta

    I think the below reference can be useful to detect partial occlusions in the 2d image:

    [1] Zhang, Tianzhu, et al. "Partial occlusion handling for visual tracking via robust part matching." Computer Vision and Pattern Recognition (CVPR), 2014 IEEE Conference on. IEEE, 2014.

    it is novel and applicable. . If I know your application , I can help more.

    I hope to be useful.


  • Iftekhar Baloch asked a question in Malus:
    Can someone share a protocol for total RNA extraction from apple (Malus domestica) leaves?

    I tried some methods but getting low concentration and bad 280/260 and 230/260 ratios.

  • Bryan Schønecker added an answer in Internet Search:
    What is the Root Cause of Epilepsy?

    From Internet search Epilepsy is “a neurological disorder marked by sudden recurrent episodes of sensory disturbance, loss of consciousness, or convulsions, associated with abnormal electrical activity in the brain”.

    What is the root cause that trigger Epilepsy?

    Are the root cause the same for children and adult?

    Which is the best treatment for Epilepsy?

    Can we prevent Epilepsy from relapse for a person who is suffering from Epilepsy? or medical treatment is the only way?

    Can Epilepsy disappears or goes away by itself after a while or will it lasts for the whole life?  If yes how long?

    Is there any negative impact on a child e.g. confidence level, introvertedness,  slow in learning, reduction in IQ & EQ etc when s/he realized s/he has contracted with Epilepsy i.e. happen for many times / episodes of fits?

    Feel free to share your professional comments / advice.  Thanks.

  • Bernd Schmeikal added an answer in Cognitive Systems:
    Is Chalmers' so-called "hard problem" in consciousness real?

    In his 2014 book "Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts" Stanislas Dehaene wrote "Chalmers, a philosopher of the University of Arizona, is famous for introducing a distinction between the easy and the hard problems. The easy problem of consciousness, he argues, consists in explaining the many functions of the brain: how do we recognize a face, a word, or a landscape? How do we extract information form the senses and use it to guide our behavior? How do we generate sentences to describe what we feel?

    “Although all these questions are associated with consciousness,” Chalmers argues, “they all concern the objective mechanisms of the cognitive system, and consequently, we have every reason to expect that continued work in cognitive psychology and neuroscience will answer them. By contrast the hard problem is the “question of how physical processes in the brain give rise to subjective experience … the way things feel for the subject. When we see for example, we experience visual sensations, such as that of vivid blue. Or think of the ineffable sound of a distant oboe, the agony of an intense pain, the sparkle of happiness or the meditative quality of a moment lost in thought … It is these phenomena that poses the real mystery of the mind”."

    Stanislas Dehaene's opinion is "that Chalmers swapped the labels: it is the “easy” problem that is hard, while the “hard” problem just seems hard because it engages ill-defined intuitions. Once our intuition is educated by cognitive neuroscience and computer simulations, Chalmers’ “hard problem” will evaporate".

    Personally, I agree with Stanislas Dehaene's opinion.

    Bernd Schmeikal · University of Vienna

    Arnold to Tausif: "These are not our beliefs. These are our internal propositions of expectation, doubt, hypotheses, uncertainties, and confusion."

    Arnold, can you specify this difference more clearly?

  • Syed Shahan Muhammad asked a question in Heterologous Protein Expression:
    Can hetrologous expression (of membrane proteins) preturb thier integration into the membrane?

    I have expressed a human membrane protein complex in insect cells (Sf21 cells) using MultiBac expression system. At time of expression the insect cells appeared to be old- but were still growing normally. My question is whether the heterologous protein expression can perturb the membrane protein insertion- in a way that the changes the native structure? I am seeing a few bands on the gel which I think might be unfolded/misfolded forms of one of the subunits. Can anyone refer a nice review paper regarding this?

  • David Camacho-Valadez added an answer in Neuroscience:
    Does anybody suggest me a nice textbook about genetics?

    Hello, I have a bachelor on psychology and making my master on neuroscience. I am going to do my thesis in a molecular biology and genetics laboratory, however beforehand, I have to study on the basics of genetics. It would be great if you would suggest a book mainly based on vertebrates.

    Thank you in advance. 

    David Camacho-Valadez · Universidad Autónoma de Ciudad Juárez

    Hello, i recommend you the courses of "Coursera.org" there you can find a lot of currently courses for many prestigious Universities; the courses are free (if you want the certified you must pay of course).

    Also, i recommend you

    Gazzaniga, M. S. (2004). The cognitive neurosciences. MIT press.  

    Best, David

  • Martha Bargiela added an answer in Organic Matter:
    Is the OSI (Organic Sediment Index [OCwt%] × [ONwt%] )useful if I want to use it to study river sediments pollution?

    I am studying the Matanza Riachuelo River. Is a poluted water course of Argentine and its sediments are poor studied. My work is in organic matter, I study the C/N ratio just to study the origin of the organic matter but the antropogenic influence makes the results no so clear. But if I calculate the OSI it is well related to the pollution of the river.

    Martha Bargiela · University of Buenos Aires

     Tnak Sergei I will read your paper 

  • Odilza Lines de Almeida added an answer in Domestic Violence:
    What can a nurse or a physician can do to prevent domestic violence after female patient discharge?

     More than three quarters of domestic violence victims who report the incidents to police seek health care in emergency rooms, but most of them are never identified as being victims of abuse during their hospital visit. What can a nurse or a physician can do to prevent domestic after female patient discharge?

    Odilza Lines de Almeida · Universidade Estadual do Sudoeste da Bahia

    Signs os domestic violence must be reported by hospital staff to the authorities to prevent new injuries.  Offenders used to control themselves when increased the propability of imprisonment.

  • Mini Dragon added an answer in E-Prime:
    How do I merge EEG & Behavioural data?

    Hi guys,

    I know the title it quite broad, a bit complicate. I don´t really know where I should start.

    Anyway, here is the situation. I do not have marker for response, but I want to exclude the error trials (behavioural data) from EEG trials by analyzer. I don´t want to do it manually, because I also would like to exclude some other trials by changing the standard of outlayer criteria.

    I got a suggestion that I can export the stimulus markers and merge with behavioural data. I thought it would be way because both EEG marker and behavioural data can be built in excel. However, the analyzer cannot read any of the format saved from excel.....

    So, my question is how I should deal this problem? Many thanks!!

    Mini Dragon


    thanks for reply. I have triggers for stimuli, but no trigger for the response. I have no problem to segment each trial. However, when come to excluding the error trials (i know which trial should be excluded), i dont want to do that manually because there are quite many:(..

    Thus I was thinking to merge the behavioral data and eeg marker data and exclude the error trials semi-manually in excel (then the deleted markers wont be included in the eeg analysis). However, i did not find a way to import the new eeg marker data back again into Analyzer because none of the format which saved by excel can be read by Analyzer...:(

  • Mahdieh Hemati added an answer in Ornithine:
    How do I induce fast growth in LUHMES cells?

    cells have been revived but growth is not that good.

    Cells are grown in ATCC medium. And plates are also coated with Poly L ornithine.

    Mahdieh Hemati · Shahid Sadoughi University of Medical Sciences and Health Services


    for inducing fast growth in LUHMES cells you can use serums that have growth factors like FBS and FCS and increase  its percentage. 

  • Inbesat Khan added an answer in Cell Isolation:
    How can individual population of myeloid and lymphoid lineages cells can be isolated from whole blood?

    Please tell me methods other than magnetic beads, column based, Sorter Based. Please let me know about simple methods as the funds are very limited.

    Inbesat Khan · Rajiv Gandhi Proudyogiki Vishwavidyalaya

    Thanks a lot for your answers. 

  • Inbesat Khan added an answer in Acute Lymphoblastic Leukemia:
    What is the difference between MOLT-3 & MOLT-4 cell lines ?

    although the details about these cell lines are given on ATCC website but i thinks there is very minor difference between the two . please enlighten me with your answers.Thank You.

    Inbesat Khan · Rajiv Gandhi Proudyogiki Vishwavidyalaya

    Thanks a lot for your immensely valuable comments.

  • Kåre Olaussen added an answer in Gravitation:
    Can two artificial bodies be built in space and be made to orbit each other ?

    I believe this is possible from gravitational laws.

    Kåre Olaussen · Norwegian University of Science and Technology

    It becomes a matter of competition with additional forces. I.e., forces from other gravitating bodies in the environment, and electric forces due to excess charges being accumulated on the bodies.

    The obvious question is why one would undertake such an enterprise. Perhaps to measure the Newton constant of gravity to better accuracy? I suspect this has already been considered and analyzed (with a negative conclusion?).

  • Kunlin Song added an answer in Wood:
    Which is the best protocol for DNA extraction from wood?

    Hi all 

    I' d like know which is the best protocol for DNA extraction from wood (unprocessed). I'm interest in the quality and integrity of DNA extracted for studies with  molecular markers (SNP's)  

    Kunlin Song · Louisiana State University