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  • Hamed Tavasoli asked a question in PEAKS:
    Separation of benzene and cyclohexane in GC

    Dear all,

    During my tests with GC I notice that my tests are not repetitive. I mean that with the same mixture I got different peaks! the retention time for each component (Bz and Ch) is the same but the area and also heights of peaks are changed in each injection.

  • Özgür Yamin Yiğit asked a question in Graphene:
    Where we can use graphene ?

    Where we can use graphene ? Alternative ?

  • Francisca Villavicencio asked a question in DEXA:
    What is the best technique for differentiating 3T3 L1?

    the standard protocol (12K DMEM + 10% FBS + 100 mM + 1 mM IBMX + 10ul insulin DEXA) has been slow to get results, it's been eight days and still are as fibroblasts.

  • Michael Tunik added an answer in Emergency Medical Services:
    In the wake of Paris and other "soft targets" attacks what are or should healthcare facilities be doing to harden the infrastructure?

    Facility hardening

    Emergency Management preplanning and exercising

    Role of healthcare in a more broad Emergency Management local community team

    Michael Tunik

    Hi Bill all.

    IMO the question actually has 2 parts. 

    Part one is what to do about disaster (read multi casualty) related incidents in a region.

    Clearly there is a need for regional coordination of pre hospital medical care, especially triage and transport locations, matching victims to hospital capacity and capabilities.  Disaster plans at all hospitals including trauma capable and critical care are needed.  Other responders have addressed these issues.

    It is not clear to me that all regions in all countries have addressed and instituted these  measures.

    The second aspect is the issue that medical facilities are definitely soft targets.  My colleagues and I published research ( Agent of opportunity risk mitigation: people, engineering, and security efficacy. Disaster Med Public Health Prep. 2010 Dec;4(4):291-9. doi: 10.1001/dmp.2010.38. Graham ME1, Tunik MG, Farmer BM, Bendzans C, McCrillis AM, Nelson LS, Portelli I, Smith S, Goldberg JD, Zhang M, Rosenberg SD, Goldfrank LR. ) that clearly demonstrated security issues is 3 major medical facilities in a large urban center.  

    In my opinion is is not an if, but when, terrorists will target not only soft targets in a community, but also critical infrastructure (eg. hospitals) at the same time. 

    The ability to "harden" health care facilities to prevent attacks on them would be expensive, and contrary to the hospital mission.   Imagine a large trauma center with police or military security at entrances, armed with automatic weapons, and all people, patients, families and health care workers alike being screened in an airport level (metal detectors, bomb sniffers, etc) manner.  This would clearly bring most routine hospital operations to a halt due to lack of people throughput.

    I dont have an answer, but the problem should be addressed, and some planning instituted.

  • Adam B Shapiro added an answer in Solvents:
    What does it mean when blank (solvent) has intense peak in excitation spectrum, but weak one in emission (<10%) of sample intensity?

    Also, sometimes I notice the reverse where weak excitation peak and strong emission peak. For the best of my knowledge, the solvent peak should be (<10%) of sample peak in both excitation and emission measurements.

    Adam B Shapiro

    Raman scatter is the most likely explanation of the solvent peak. It is easily tested by looking for a shift in the peak wavelength in the same direction as a change in excitation wavelength. That said, there could also be fluorescent contamination of the solvent.

  • Christian Mathiszik added an answer in Hall Effect:
    What type of sensors can be used to analyze a magnetic flux density on a surface of a sample?

    I am planing to analyze magnetic flux density on a surface of samples. The material will be low alloyed steel with a ferritic microstructure. The range of the magneitc flux density will be lower than 0.2 mT. So far, I used Hall effect sensors. What other sensors can you suggest?

    Christian Mathiszik

    Thank you very much for you answers. The geometry of the samples are two or three steel plates joined by resistance spot welding. After welding the samples are magnetisized with coils perpendicular to the surface from both sides. Measuring the remanence by scanning the samples on the surface, good weld show different behavior than bad welds. So far I am using Hall effect sensors because they are very cheap and easy to set up.

    @ Kai Fauth:I would love to analyse some samples with a magnetic force microscope and discuss the results with you.

    For better understanding, why I am doing this, feel free to visit:

  • Debra Sharon Ferdinand added an answer in Classroom Research:
    I am investigating the 'Art and Social Practice' program, do any educators have experience with this either in the classroom or as researcher?

    Has anyone applied their knowledge and or experience gained from the 'Art and Social Practice' program in a post secondary education setting? Or, what would be, or is the application of this program to education, public art, higher education practices, etc.? Do any recent graduates have jobs at PSU? 

    Debra Sharon Ferdinand

    I have used the art of debating as a social practice in my higher education sessions online with much success. I am included a recent conference paper on how the latter worked and the outcomes, which I hope would be useful.

    Best regards,


    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: The Debate (i.e., arguing for or against the topic, giving reasons to support or oppose it) is a dynamic teaching tool (for both f2f and online classes) that engages high school/university students’ critical thinking, communication, collaborative, and research skills, in mastering the course content across subject disciplines (O’Mahoney, 2015). A good debate topic (moot) is topical, relating to students’ prior reading, experience, or societal/global issue in motivating students to participate to win. The debate usually has three rounds: (1) Students make an initial argument for or against the moot, clarifying key concepts; (2) Convincingly rebut their opponents’ arguments; and (3) Summarize their arguments, rebutting or defending key points. Teachers are motivated by students’ enthusiastic exchanges, noting improvements in their understanding and mastery of the course content (Akerman & Neale, 2011). Students’ debate assessment include quality of their collaborative debating strategy, debating arguments, and presentation (includes eye contact and oratory skills).
      The 16th Annual Midwest Scholarship of Teaching and Learning (SoTL) Conference, Indiana University South Bend, Indiana, U.S.A.; 04/2015
  • Shah Jahan Leghari added an answer in Oil Palm:
    How long after applying nitrogen fertilizer in soil can I sampling from leaves?

    The tree is oil palm ,and I know it depends on the age of the tree and the extend of the root ,but I want to know when is the best time for sampling leaves to determine whether the amount of fertilizers applied was enough? Do we have any role for that?

    I want to take a picture by satellite and UAV to compare between nitrogen content in aerial images and ground data that's why I want to know when is the best time for leaves sampling after applying nitrogen in soil. generally not exactly

    Thanks in advance.

    Shah Jahan Leghari

    Nitrogen usually plants response to N quickly. so after application of N to plant you can measure leaves sample within 15-30 days. But first you should study factors. plant age factor is most important.

  • Leonard Kyei asked a question in Mathematical Statistics:
    Can Someone please help me with a paper or an article on how to develop your own probability distribution?

    Statisticians and mathematical Statistics

  • Lijin George asked a question in Graphene:
    What is the reason for growing Few Layer Graphene on copper foil on CVD growth even if the growth of graphene is discussed as the self limited?

    while changing the condition I am getting FLG. But the literature says graphene growth is self limitted so what is the reason for forming FLG on SLG on copper foil.

  • Roman Kubrin added an answer in BET:
    Is there Al2O3 available as corundum nano-powder with a spec. surface higher than 15 m2/g?

    I'm looking for corundum nano powder with a BET > 15 m2/g and a particle size smaller than 200 nm to create an easy sintering pure alumina matrix at 1200 °C.

    Roman Kubrin

    In some cases, it may be possible to avoid degradation of integrity of the structure due to phase transformations of alumina even in complex geometries (or, also possible, exactly due to the special shape of the structure):


  • Srimanta Manna added an answer in Lignin:
    Which solvent can be used to dissolve lignin (dealkali) ?

    Which solvent can be used to dissolve lignin (dealkali) ?

    Srimanta Manna

    water is not good for my case ....

  • Maryna Moroz added an answer in Lipofectamine:
    How do I identify dead and live THP-1 macrophages after transfection with Lipofectamine?


    I differentiated THP-1 with 200nM PMA for transfection experiments. After transfection the cells had significant morphological changes. Most cells had bubbles inside and irregular form and some cells look like they are detached. Could anyone suggest what cells I should consider as apoptotic cells and which cells are live?

    + 2 more attachments

    Maryna Moroz

    Anton thank you very much for your help!

  • Stephen Asatsa added an answer in Attachment Theory:
    Does anyone know of a standardized questionnaire to measure the four attachment styles?

    Who has any standardized questionnaire measuring the four attachment styles?

    Stephen Asatsa

    My interest is adolescents

  • Mohd Shamsuri Md Saad added an answer in Crowdfunding:
    What is your attitude towards Crowd Funding project creators?

    Participate in my online research and you will assist me in determining what impact, if any, a Crowdfunding project creators identity has upon potential contributors. The research requires 250 respondents, so your assistance will be greatly appreciated.  Please follow this link to participate: http://crowdfundinglab.weebly.com

    Mohd Shamsuri Md Saad


  • Bimali Weerakoon asked a question in Distribution:
    What can be the limitations of the T1 quantification of Gd-DTPA concentration determination using Spin Echo in MRI ?

    If I  want to apply the coefficient of variation of signal intensity as an indicator of the distribution of Gd-DTPA over the cross sections (uniformity of the contrast distribution over the cross sections) of a fiber phantom, instead of doing the T1 quantification to find out the contrast distribution, What factors should I consider? what factors will be the limitations? and what are the positive factors (advantages)instead of T1 quantification (at least few)?

  • Roman Kubrin added an answer in Calcination:
    What are differences between calcining and sintering processes?

    In a paper, the authors talked about calcining and sintering materials. How to identify the two processes?

    Thanks for any response!

    Roman Kubrin

    Sintering is usually meant to have a goal of consolidation of powders into solid parts of certain shape without pores or at least with much lower porosity as in the initial state. Calcination is a heat treatment for changing the properties of a powder (removal of organics, change of the crystalline phase, etc.), which is not supposed to result in shaped dense parts but is intended to produce again a powder at the end.

  • Michele Di Foggia added an answer in Fourier Transform Infrared Spectroscopy:
    What is the reason of shifting FTIR curve picks to higher or lower wavenumbers?

    i have recognized the bonds which refers to any pick.but can anybody help me please to find the  reasons for picks transfer by changing the materials used for our mixture? here is a sample of FTIR analyse 

    thank you

    Michele Di Foggia

    The position of a peak is proportional to the strenght of the bond whose vibration has the same frequency of the IR photon; so if a bond is weakened after the interaction of the molecule with something else (a solvent), the vibration frequency decreases and its wavenumber decreases too. For example if carbonyl bond is coniugated, its wavenumber lower of about 30 cm-1. H-bonding has normally a huge effect on wavenumber position of NH and OH bond

  • Jose Miguel Sandoval-Gil added an answer in Plant Molecular Biology:
    Does anyone know what's the range of protein concentration in plants (mg/ml)?

    In few works I've found values between 1-4 mg/ml, but I'm not sure.

    Jose Miguel Sandoval-Gil

    Oléeee esta Beatriz! muchas gracias por tu rápida respuesta! espero que todo te esté yendo genial; seguro sí! 

  • Ronny Steen added an answer in Scripting:
    I need volunteers for testing a R-script I have written (with help from colleagues) - can someone help?

    I have used existing packages and written some functions to extract the metadata from the video files and automatically create a data frame with the date, time and image ID for each video clip, thereby avoiding the need to type in the data manually.

    Since the script will be supplied as supplementary material for a paper, I prefer that the script is tested thoroughly before handing it in.

    Let me know if you would like to test the script for me and I will give you access to the script and the folder containing the video clips. 



    Ronny Steen

    H Julia,

    Thanks for reply.

    I try to auto process a bulk of images/videos by customizing a R script. Generally it is not a problem, as most of the files are from same timezone as my local computer. Although, to make the script more general I wish to consider e.g. files from different time zones. I have just tried exiftool and made a call in R to get it integrated, and it works. Although for some files, e.g. from my Browning Strike Force (camera trap), the Exiftool doesn't read creation date, see attached file.

    If I understand it right, the modification time depend on the local computer. Further, if you change name or downloading the file from a server the modification time will change. If the file is kept, copying is okay, the modification time will be the original time. When sharing, one could omit this by using ZIP-folder. For an example see attached files, a .avi-file from Browning Strike Force (timezone "America/Toronto") and the same file enclosed in the ZIP-folder "Example". The modification time for the .avi file will most likely change to the time you download it, but the .avi-file within the ZIP-folder will stay as original (although in your time zone). The .avi-file enclosed in the zip-folder, could be conversed to original time as long as you know the original timezone. I have do hope that the script below could be used. 

    ###Read metadata of the the attached video file to get 'mtime', this will be used later###

    file.info("C:/Videos/IMG_0017.AVI") # Has to be changed, this is the path to the downloaded video file, use the one from ZIP-folder

    ###Get the timezone of the computer that you have downloaded the video file###

    local.time.system<-Sys.timezone(location = TRUE)# current timezone of the computer

    ###Specify the 'mtime' that will be converted###

    mtime<-"2015-06-10 15:11:44" #Has to be changed, enter the modification time 'mtime' that you achieved from file.info()

    #Using library(lubridate) to convert the 'mtime' to orginal time when the video was taken.

    time <- ymd_hms(mtime, tz = local.time.system)
    time.orginal<-with_tz(time,"America/Toronto")#convert mtime into the time which image or video was taken at origin location

    [1] "2015-06-10 09:11:44 EDT" # which correspondence with the time displayed on the video. I hope everyone get the same time by following my script.

    + 1 more attachment

  • Debra Sharon Ferdinand added an answer in Descriptive studies:
    What kind of checklist that i can use to assess my cross-sectional and descriptive study for quant data except CASP checklist for quant study?

    all researchers 

    Debra Sharon Ferdinand


    Here's a link to some additional guidelines that can be used to check or assess your descriptive quantitative study:


    Best regards,


  • Donggyu Jang asked a question in PEAKS:
    Could you provide me any comments for ground construction for new lab?


    Our lab has significant portion of job associated with the single-shot HV (High Voltage) gas discharge. Peak current is several hundreds amperes and rising time to peak is about ~ 100 ns. HV is up to 35 kV and considered to be further increase.

    We're going to move new lab which is 3rd floor. I mostly worry about weakening of the lab ground due to such a height with respect to soil. Current lab is in 2nd floor and has additional ground connections directly to the soil with 25 mm^2 wires, but our experience tells that this ground is not good enough for transient discharge time. Every conductors inside the lab are fluctuated with huge degree over such a short time so some of sensitive instruments becomes malfunctioned, although we've tried our best to ground all metals as much as possible.

    I guess future ground setup in new lab has to be more reliable and I am thinking that ground wires can be replaced to some sort of copper bar or plane. Could you provide me any suggestions to this new ground construction like recommended physical dimensions of ground conductor to the soil from lab? 

  • Sushilkumar A. Jadhav added an answer in Copolymerization:
    Why does a new material contain another material?

    I will buy a bottle of CMA monomer at Aldrch for co-polymerization.

    But there is a message like this

    " ≥97%, contains ~60 ppm monomethyl ether hydroquinone as inhibitor (Aldrich) "

    Why that material is in ? (why the inhibitor is required)

    And how can I use that? Sould I filter that out for polymerization?

    In the another case,

    A material is in the acetone (12 wt%).

    so, should I dry that solution and get the powder for polymer additive?

    or exactly calculte the solute's quantity?

    Sushilkumar A. Jadhav

    Some photo (light) sensitive reagents are marketed with stabilizers, as in your case they have added the stabilizer which will self oxidize from hydroquinone to quinone. If you are not using photo-polymerization technique it will not interfere considerably. Anyway you can look for purification or simply recrystallize the monomer and get rid of the stabilizer and other impurities.

    As far as the solution in acetone is considered if you do not require a solution of the monomer in acetone you should look for the powder. OR if you carry out the polymerization in acetone you can use it as it is.

  • Christophe Gibout added an answer in Cultural Anthropology:
    Which cultural studies theories would best describe the hacker subculture?

    Which Cultural Studies philosophers and which concepts would be best used to examine and analyze the Hacker subculture?

    I ask only because the hacker subculture is really vague and has been flesh out to a certain degree in graduate studies but not in undergraduate studies

    Christophe Gibout

    I am agree with the proposal of Stephanie Robert (Michel Maffesoli, time of the tribes) . He is not italian but french. Probably his later works should be more usefull, specially few articles published both in "Societé" and "Cahiers européens de l'imaginaire", both are french/english speaking sociological review.

    Concerning the use of "Outsiders" from Becker, it seems to me that it is a "classical book you need to read of course...

    Good luck for your research,

    All the best,


  • Dia Eddin Nassani asked a question in SAP2000:
    Model brick walls in the design of steel structure using Sap2000?

    what is the best way to model a brick wall in the design of steel structure with effect of seismic loading using Sap2000?

  • Jorge Cuéllar-Anjel added an answer in Fisheries Science:
    What is the required protein of siganids/rabbitfish during culture period?

    Being an herbivorous species in nature, I want to know the different protein requirement per life stage of rabbitfish (family Siganidae) for culture purposes.

    Jorge Cuéllar-Anjel

    You can have as a guide the following document:


  • Abdulhafeez Mohamed Khair added an answer in Progressive Myoclonic Epilepsies:
    Is there an effect of hippotherapy on children with dravet syndrome?

    Is there an effect of hippotherapy on children with dravet syndrome?

    Abdulhafeez Mohamed Khair


    I don't think you find much in available literature, but they are a bit more in individual forums` stories. 


    I have scanned one study though, who has found  a potential benefits of hippo therapy in another epileptic encephalopathy syndrome; which is ohtohara syndrome.

    H. Komaki, K. Sugai, M. Sasaki et al., “Surgical treatment of a case of early infantile epileptic encephalopathy with suppression-bursts associated with focal cortical dysplasia,” Epilepsia, vol. 40, no. 3, pp. 365–369, 1999

  • Damianos Christophides added an answer in Variational Linguistics:
    Can you advise me a tool for data crunching and data analysis?

    For most of my projects I use R to manage my big data and firing statistical analyses on the results. My domain of research is linguistics (computational linguistics, corpus linguistics, variational linguistics) and in this case I'm concerned with big heaps of corpus data. However, R feels sluggishly slow - and my system isn't the bottleneck: when I take a look at the task manager, R only uses 70% of one CPU core (4 cores available) and 1Gb of RAM (8Gb available). It doesn't seem to use the resources available. I have taken a look at multicore packages for R, but they seem highly restricted to some functions and I don't think I'd benefit from them. Thus, I'm looking for another tool.

    I am looking at Python. Together with Pandas it ought to be able to replace R. It should be able to crunch data (extract data from files, transform into data table, mutate, a lot of find-and-replace and so on) *and* to make statistical analyses based on the resulting final (crunched) data.

    Are there any other tools that are worth checking out to make the life of a corpus linguist easier? Note that I am looking for an all-in-one package: data crunching and data analysis.

    Damianos Christophides

    Hi Bram,

    you can also interface Python to R using a package like rpy2 (http://rpy.sourceforge.net/). 

    I mainly use Python but sometimes I would prefer to do some statistical analysis in R. For example you can use Python's sklearn to perform ROC analysis (metrics.roc_curve()) but I find the R package 'pROC' more streamlined for this purpose. 

    I believe that you are making the right choice by moving into Python. Python is a programming language with many scientific libraries that make it a complete scientific package. R is mainly dedicated to statistics and in some instances can provide functionality not easily accessible through Python.

  • Rajendra Kumar Mohapatra added an answer in PSCAD:
    How can I set supply X/R ratio, transformer R p.u and X p.u in PSCAD?

    In mathematical calculation, the MVA rating, kV and X/R ratio of the supply & the R p.u and X p.u of the transformer are used to calculate the inductance of the total source impedance. This inductance value is later on used to determine the values of capacitor banks that will cause resonance in a system with harmonics presence.

    I wanted to simulate a 3ph non-linear load system (bridge rectifier with RL load) to show the resonance problem in PSCAD hence I'm doing a reverse calculation of the required capacitor bank to cause resonance. Mathematically i have the figures required. However, I am stuck at how to set the mathematical parameters above in PSCAD. 

    Appreciate the help. Thanks.

    Rajendra Kumar Mohapatra

    The X/R ratio is dependant on the impedance and loss level of transformer.