Q&A

ResearchGate Q&A lets scientists and researchers exchange questions and answers relating to their research expertise, including areas such as techniques and methodologies.

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  • Christer Hydén added an answer in Traffic Safety:
    What is post-encroachment time regarding Un signalized traffic intersections? what are the methods (manual methods especially) to measure this PET?

    Im looking for evaluating traffic safety at un signalized intersections by micro simulation. while reviewing related literature, I came across a term 'post-encroachment time'. So, I kindly ask for some related information.

    Christer Hydén · Lund University

    I have looked for a basic reference. However I only found the following: THE TRAUTENFELS STUDY
    A diagnosis of road safety using the Dutch conflict observation
    technique DOCTOR. You find it on http://www.swov.nl/rapport/R-85-53.pdf

    It gives a reference to the basic development of the DOCTOR technique, which combines TTC and PET (Kraay et al 1986). I can not find that one though. May be you can look further.

  • Tamara Heredia added an answer in Keratinocytes:
    If I have cultured keratinocytes expressing only K14 gene, is it possible that under certain conditions, they become activated and express K16?

    If I have cultured keratinocytes expressing only K14, treated with IL-1ß, is possible that they become activated and therefore they express K16?

    That happens in basal keratinocytes, but I am not sure if "cells that express only K14 gene" means that all the other genes are not there, or they are just inhibited  and eventually they could be activated).

    Tamara Heredia · University of Leipzig

    Thanks for your suggestions but the thing is that I am working with K14 to study the effects of interleukin1ß on it. Therefore, I wanted to understand how it works, if genes can become activated? or if my cells only have K14 genes, that means that is impossible to have an activation and thus they cannot express K16??? I am not sure about that. And I need to understand that point. Also, in case of Knock out keratinocytes is possible that genes become activared??? or if they lack all keratins there is no possibility that genes become activated???   Thank you all. All the suggestions are welcome

  • Andrew G King added an answer in Scoliosis:
    Do you routinely use antithrombotic prophylaxis in scoliosis surgery for children and adolescents ?

    This issue is very controversially or undiscussed at all in the pertinent literature. On the one hand this kind of surgery may last for hours, and on the other hand this prophylaxis is not commonly used in children. What is your approach and practical experience ?

    Andrew G King · Louisiana State University Health Sciences Center New Orleans

    Have not experienced a single case of PE or clinically obvious DVT in 35 years of scoliosis surgery with over one hundred cases a year, with quite a few cases aged late in the second decade, and with high BMI!

    so no prophylaxis apart from TED hose placed immediately before surgery and kept on for 2 days post op.

  • Mustafa A Adhab added an answer in Aphids:
    Where do turnip aphids exist?

    Hi,

    I wonder if there is anybody who could help with distribution and identification of turnip aphids. What is the most popular ID key used to identify this species? Where have turnip aphids been reported? Especially across the US. What are the suitable conditions for this species?

    Thank you in advance.

    Mustafa

    Mustafa A Adhab · University of Missouri

    @ Qasim,

    Thank you so much.

    Mustafa

  • Why all journals don't follow one universal style of research publication?

    Every journal has different rules of writing style, bibliography style, figures presentation, number of references, number of figures and number of tables, number of pages limit etc. All this is to show a "finding". Can all journal editors meet and come to a common style. It will save a lot of time of researchers when they publish in different journal.

    Subhash C. Juneja · Toronto Western Hospital

    My point is that every journal has put 30 pages instructions which waste a lot of time of people just to adhere to those instructions, just a common format will be helpful and will not waste time. Still each journal will have its own impact and having a common format.

  • Why is there vacuum in some of the high voltage power supplies of an EB welder?

    Also what is the role of insulating oil? Its somewhat obvious from name, but still need clarification.

  • How do you teach meaning in foreign/second language acquisition?

    Some teachers of English,and me too, follow the Modern Language Association Report of 2007 which promotes teaching meaning by the use of various methods and disciplines of knowledge.

    Janina Wiertlewska · Nicolaus Copernicus University

    Dear harikrishna and Pabio ,

    I'm grateful to you for expressing your opinions on teaching meaning in a foreign language. We all have differet points of view and that''s very good.

    Regarrds,

    Janina

  • Devin Hosea added an answer in Methadone:
    Combination of methadone and morphine?

    Methadone maintenance is in the patients perspective a quiet "boring" drug. We think that not only cocaine is often used in high dose maintenance, but also alcohol (carbonic acid + alcohol = "cick"). My question is:

    Does anybody know wheher there are combination maintenance programs with fast acting morphine in daytime and low methadone for the night?

    regards

    c. jellinek

    Devin Hosea · Princeton University

    Chaim,

    I meant mostly to contrast your program to the policies and procedures in most treatment centers here in the US.  You say "opioid addiction needs OST" - I agree that for some patients, that is true.  But there is also plenty of evidence that opioid use disorder can be treated successfully with (a) abstinence-based methods (b) bridging to abstinence with OST - e.g. as an intermediate term treatment and (c) even with medications like naltrexone, especially in sustained-release injections (Vivitrol, etc) which also work for alcohol.  That said, I agree that OST has a very useful role to play for many patients, and as I wrote, there are substantial risks to discontinuation of OST.

    From a pure social policy standpoint, you are right - insisting that patients discontinue all substances of misuse in order to receive OST is draconian and may cause all sorts of harm -- relapse to illicit opioids, increased risk of HIV, mortality, etc.  I am just highlighting the "culture" difference between Europe and the US on OST.  Here, the prevailing view (from dozens, if not hundreds of addiction docs I speak with) is that OST should not be administered to patients who are misusing other substances.  I am not saying that is RIGHT, I am just saying that is the policy here, and indeed, by law in the US, a patient  may not continue to receive methadone if he or she tests positive for any substance of misuse - alcohol, etc - unless it is legally prescribed by a physician.  Again, I don't necessarily agree with this policy, and I know that it is ignored in some cases by treating physicians.  

    While you correctly point out the risks of discontinuation of OST, your original question was how to treat the issue of a patient feeling "emotionally dead" while on either methadone or buprenorphine.  I still think there are only three options: (1) dosage adjustments - e.g. some patients are overmedicated on methadone, e.g. above 80mg a day there is little evidence of added relapse prevention (2) a path to abstinence of some kind or (3) additional medication to treat the emotional numbness - but this would be a stimulant of some kind, and that might be dangerous in a patient prone to addiction.

    In my view, effective OST poses challenges in terms of patient quality of life.  YES, it saves lives, and yes, it prevents HIV, and so forth.  But the tradeoff, for some patients, is that they don't like the way "it feels".  I suppose the same can be said for cancer patients on chemotherapy; they too have a chronic illness and must suffer in some ways in order to save their lives.  On the other hand, there is evidence that many patients do very well on buprenorphine - many report antidepressant effects (long term) - in fact, there is a new antidepressant drug being developed here that is based on buprenorphine.  I can find the article about buprenorphine's antidepressant effects; I read it about a year ago...let me know if you would like it.

    In any case, I wish you the very best in managing your OST patients.  You are doing noble, life-saving work.  I mostly intended to point out the differences in approach between US OST and EU/German OST. 

    Very best regards,

    Devin

  • Parviz Heidari asked a question in RNA-Seq:
    How can i find or analyze co-expression genes in RNA seq results?

    I have a data set of RNA seq and i want to find co-expression genes in this data.

    Does anyone know which software or data base is suitable for my story?

  • Unsuccessful GO prep by Tours' method, possible reasons?

    I tried to prepare GO by using the tours method, however, XRD analysis shows no presence of GO.

    I've attached both the method used and XRD results, would like to hear back from people who have successfully prepared GO using this method.

    Thank you.

    Søren Vermehren Petersen · University of Copenhagen

    Oh and another things, I noticed that you doent use very much sulfuric acid compared to what I use. For that amount of graphite I would use 92 ml koncentrated sulfuric acid. 

    Cheers, gl 

  • Stoyan Stoychev added an answer in Protein Pilot:
    What is the meaning of threshold while using protein pilot ?

    what is the meaning of threshold while using protein pilot for identification of a protein and how can it is correlated with the significance of the identification....????? please explain in detail.

    Stoyan Stoychev · Council for Scientific and Industrial Research, South Africa

    My understanding is that the threshold is what is set as the minimum value above which proteins are considered as significantly identified. It's a value that you would set within PP. The significant value (or protein confidence) is calculated from the peptide cofidences for each protein and log converted to the Unused /Total Protein Scores. The peptide confidences are in turn calculated from the corresponding peptide scores which are basically based on number of experimental MS/MS ions matching to theoretical ions. If you are performing a large scale Proteomics experiment can do an FDR analysis which will help you set your threshold appropriately. 

  • John Macken added an answer in Transfer:
    Why does a photon transfer all its energy to an electron (and disappears) rather than transferring part of its energy and continuing to exist?

    The photon CAN transfer part of its energy to the electron and continue to exist. An example of this is Compton scattering, where a gamma ray transfers enough energy to the electron to ionize and move it out of the atom's potential well, but my question is about electronic transitions in the visible spectrum.

    John Macken · Saint Mary's College of California

    Nabeel:    Your question probes the limits of our understanding of physics. Therefore an answer can be given in two different ways. One type of answer can be reduced to: What part of "quantum" don't you understand? This obviously is unsatisfactory. The other alternative is to propose a conceptually understandable answer which extends outside of mainstream physics. That is the approach that I will take.


    The paper available in the link below proposes that everything in the universe (all particles, fields and forces) are all different manifestations of 4 dimensional spacetime. This explanation eventually produces quantification of energy. We start by describing the quantum mechanical vacuum. Field theory requires that the vacuum has energy density about 10120 times greater than the “critical” energy density of the universe obtained from general relativity. This paper explains how this enormous energy density is possible. Small amplitude waves in spacetime are proposed and quantified (amplitude, frequency and impedance of spacetime). Ultimately, spacetime is pictured as a sea of small amplitude waves which lack angular momentum and collectively possess superfluid properties. All superfluids isolate angular momentum into quantized units (examples given). Fundamental particles are proposed to be ½ ħ of quantized angular momentum which exists in the superfluid spacetime field which lacks angular momentum. Photons are a different structure with ħ of quantized angular momentum.


    All of this gets to the answer to your question. Photons transfer quantized units of energy because they propagate in a superfluid medium which isolates angular momentum into quantized units. Quantized energy is a byproduct of transferring quantized angular momentum. The article goes into much more detail including the derivation of the gravitational and electrostatic forces.

  • What are guidelines to be a good entrepreneur ?

    I am planing to start a biotechnology company mainly focusing on training students to be better researchers (R&D) ,laboratory supplies and academic publishing (Three Wings).What is your advice for a beginner like me ? How I can be successful entrepreneur ? 

    Chandrasekar Raman · Kansas State University

    Here is my few suggestion may be help full:

    1. Consult with en-number people (academician, publisher, good teacher, web designer etc)

    2. Plan  (pilot project, minor  project and major project) and executes 

    3. Try to make first net work  within your local area, national level  as well as international level.

    all the best 

  • How can I analyse the frequency of any audible sound ranges from 20-20000 Hz?

    I am working with audible sound profile and want to analyse the frequency of that sound profile. So, Is there any method by which frequency could be analysed??

    Sebastià Vicenç Amengual Garí · Hochschule für Musik Detmold

    The most extended approach to analyse signals in frequency domain is the Fourier Transformation. If you are working with discrete data, then you should go for a Discrete Fourier Transform. Depending on the characteristics of your signal and your purposes you can go for several approaches: for periodic signals use FFT (an optimised implementation of the DFT), for time changing signals you can use the Short-Time Fourier Transform using a time moving window (the size of this window will depend on the requirements of time and frequency resolution).

    You can find different implementations of this algorithms on available free software. I recommend you to have a first try with Sonic Visualiser. If you use a spectrogram representation (graphical representation of the STFT) you will be able to see graphically the dominant frequencies of the analysed sound.

  • Why are people (dis)honest?

    "Rooted in the philosophies of Thomas Hobbes, Adam Smith, and the standard economic model of rational and selfish human behavior (i.e., homo economicus) is the belief that people carry out dishonest acts consciously and deliberatively by trading off the expected external benefits and costs of the dishonest act (Allingham and Sandmo 1972; Becker 1968). According to this perspective, people reach a decision that maximizes their interests and are honest or dishonest only to the extent that the planned trade-off favors a particular action (Hechter 1990; Lewicki 1984).

    From the "The Dishonesty of Honest People" one of the most cited article (see)

    http://people.duke.edu/~dandan/Papers/PI/Dishonest_JMR.pdf

    I am interested to know your opinion about

    Douglas R. Daugherty · University of New Mexico

    Dear Sayed,

    As to why, I would propose something to the effect of "a dishonest person is a person who selk-centered" meaning self first.

    1) This would include being dishonest in the questions I, Ljubomir, and Huajang posed as having a conquence to.

    2) It also would include all the other great researchers who have posed the other side of the coing which is what the dishonest person whould gain.

    3) I think the real question has been posited by Kazaros when he askes "It will be interesting to consider the case when one is punished if he acts honestly and benefits if he is dishonest without any punishment".

    4) The answer to that question is the monemt of truth between a dishonest person and an honest person don't you think"

    Douglas 

  • Md. Aminul Islam asked a question in Affymetrix:
    Choice of R/bioconductor annotation package for Affymetrix porcine gene 1.0 ST array data set ??

    Could anyone please tel me about the right choice of Bioconductor annotation package for Affymetrix porcine gene 1.0 ST array data set?

  • James Kilgore added an answer in Pichia pastoris:
    How I concentrate from 2.5 mg/mL to 90 mg/mL of Insulin precursor?

     Insulin precursor (IP) is produced by fermentation process of methylotrophic yeast Pichia pastoris. We concentrate IP by using Gigacap resin in Akta explorer.

    James Kilgore · JLK Bioorganic Services

    Since you are doing almost 50-fold concentration, precipitation is your first option.  Ultrafiltration will be extremely slow, particularly as your polypeptide solution becomes more concentrated.  Which precipitant additives are acceptable will depend largely on your downstream steps - I assume you need concentrated precursor for the peptidase steps producing mature insulin?  General purpose precipitants are naturally (NH4)2SO4 and PEG.  Ammonium sulfate could be advantageous if you can use a hydrophobic interaction bind-and-bump operation to remove most of the salt, but elution from the HIC support will likely result in too much re-dilution.  (This might, however, give material pure enough to lyophilize.)  PEG occluded in precipitates generally won't interfere with subsequent enzymatic processing, but you may have trouble removing it from the final product.  Finally, a cool low-tech method for concentration is to fill a dialysis bag (2 kD MWCO?) quite full before tying off ends, then place it in a beaker of solid PEG (use much higher MW, say PEG 20000).  Water and small molecules wick out leaving the polypeptide behind - this is good for ~ 3-fold to 10-fold concentrations, and although passive, often works faster than stirred-cell ultrafiltration. 

  • Hanno Krieger added an answer in Liquids:
    What Kind of Project you Dream to Have ?

    I am personally is, largely, Theoretician. So, I used to find Theoretical Problems within Projects I had. My superiors could not care less, as no additional money were requested for a Theory. 

    But in the year 2,000 I came with the idea of Plazma within the Liquid Chemical Reactor, for destruction of liquid poison without combustion. That was an Experimental Project, requested $250,000 to start. HAVS rejected idea to spent money for unproven technology.  But I fought hard, brought private investors, which funded 50 % of the budjet. So, the Alberta Research Council Management gave up. coming with remaining 50 %, or $125,000. Reactor worked with fliying colors, US Patent was granted and is attached. Sure, lawyers killed the text, which is hard to follow.

    Hanno Krieger · retired from Justus-Liebig-Universität Gießen

    Dear Sarwan,

    a very amazing whish. I hope you will find a chance.

  • Nashwan Yousif added an answer in Castor Oil:
    Zinc castor oil ointment BP is mentioned as cream also in the same BP monograph, why ?

    The British pharmacopeia monograph of Zinc castor oil ointment states another name which Zinc castor oil cream, although the formula stated and the method of preparation and evaluation are all clearly of an ointment. Why did the BP mention the two different names of preparations having different pharmaceutical properties for one product in the same monograph ?

    Nashwan Yousif · Ministry of Health, Iraq

    Thank you Mr. Ali

    I'm afraid I can't find a relationship between the API and the type of the pharmaceutical  preparation, as one API can be present in preparations of different pharmaceutical properties like creams, ointments, lotions, etc. and you can check that at the Drugs. com site. Note that the BP clearly differentiates between cream and ointment in other monographs for other preparations.

    Regards

  • Report impurity peaks with responses NLT that of the peak in the Reporting threshold solution (0.05%) ?

    I have A method of analysis by HPLC (assay and RLTD method ) The concentration for Assay 3mg/lm and Diluted Standard For RLTD 0.03mg/ml The method Say Report impurity peaks with responses NLT that of the peak in the Reporting threshold solution (0.05%) ?/??? 0.05 % What meaning 0.05 % From Assay concentration or RLTD concentration and why Please?

    Selva Chemist (Bio) · GreyMatterResearch Foundation, India

    Dear Salah Sadeq,

    0.03mg/mL possible to use but your instrumental condition you should need to change., because of high concentration of your sample the deduction time respond slowly so that you are receiving threshold at 0.05, your injection in higher concentration it's not required,

    Suppose you want to separate your target means you use this concentration or higher but use RP-HPLC preparative method., and your column may be not suitable for your specific analysis i feel your column is c8 so that it will take very long respond so you got this problem.,

    if you use some big diameter column and doing the same means you will feel the difference.,

    Hope you Got

    Good Luck & Regards

    R.Selva....   

  • Patrick Druggan added an answer in AST:
    What is recommended for performing AST on 5% defibrinated sheep or horse blood?

    Is AST on 5% defibrinated sheep or horse blood better for MHA?

    Is there a big difference between sheep blood and goat blood for MHA preparation? 

    What is your experience on the quality of a bacterial growth colony?

    Why?

    Patrick Druggan · Synergy Health, Chorley, United Kingdom

    There are specific organisms that enriched MHA are used for according to the EUCAST guidelines. There are differences in the blood types, for instance defibrinated horse contains a significant amount of NADH, which means this does not have to be added to the medium when growing Haemophillus. If you were using sheep blood you have to ad NADH to MHA for growing H. influenzeae. I do not know what the NADH content in goat blood is, but I would check it out with H. influenzeae.

  • Louis Brassard 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.

    In mature field of science, reworking of the frameworks are rare events but those working on bringing about these events have to think sometime decades at the philosophical level in parallel with more normal scientific activities (Kuhn).  But in immature field such cognitive science, science of consciousness these events are not rare because the foundations are not solid and are not integrated into a core theoretical framework.  These sciences are at the pre-paradigmatic stage if we use Kuhn terminology.  The field of abiogenesis is such pre-paradigmatic field.  In such field there is plenty of different approaches and it is difficult to call it a field because those pursuing one avenue have no much to say to those pursuing another avenues.  An the reasons why one choose one avenue instead of another one are often based on intuitive aesthetic philosophical considerations. In your case, the rejection of a boundary between non-life and life have been an important aesthetic philosophical consideration.

  • What are the best soft wares for primer design?

    Polymerase Chain Reaction is widely held as one of the most important inventions of the 20th century in molecular biology. Small amounts of the genetic material can now be amplified to be able to a identify, manipulate DNA, detect infectious organisms, including the viruses that cause AIDS, hepatitis, tuberculosis, detect genetic variations, including mutations, in human genes and numerous other tasks.

    Now I want to design primers for detection of cancer cells apoptosis by myself, and need help to guide me for a good soft ware. TQ

    Saumyadip Sarkar · Institute of Life Sciences

    I offen use Gene tool software for designing and Primer3 is also good. NCBI also allows you primer designing online but its better go for softwares.

    Actually Gene tool software allows primer designing along with other additional genetic tools.

  • What are the site effects using ambient vibration and the spectral ratio method?

    Using the spectral ratio method

  • Jane Err added an answer in Language Center:
    Any theory/studies in Second Language Learning at a young age ( birth to 3)?

    Not Language Acquisition, but bi-literacy or methodology

    It can be pedagogy in language centers, families, private or tutoring, community centres.

    Not academic setting (preschools or primary)

    Jane Err · City University of New York - Hunter College

    Here is a list of links provided by a professor several years ago from a course on ELL for early childhood.  I don't know if they are all applicable...but you can explore if you like.  There may be some tips within them that are helpful.  Some relate to tips for inclusive multi-cultural teaching, and others are for older children...but may also be helpful.

    As indicated in a previous response, the number one strategy is to have one parent speak in each language all the time (at least when speaking directly to the child).  That also includes, reading books in the representative language.  However, you are likely to discover that it is best not to read the same book in different languages, because with repetition they will learn what comes next (and be able to predict), which they love, but becomes irritating to them when it is not consistent...at least for a two year old, who does not understand why it is different with each parent (due to language), and perceive one as reading it "wrong."

    http://iteslj.org/Articles/Bradley-Scaffolding/ Article: Scaffolding for second language learners. 

    http://www.llas.ac.uk/resources/gpg/2175 Article: Writing in a Second Language 

    http://www.learnnc.org/lp/pages/672 Article: Writing and English as a second language 

    http://www.evergreen.edu/k12outreach/docs/2ndLangLrners.pdf  Article:  Reading and Second Language Learners 

    http://www.alliance.brown.edu/tdl/elemlit/writing.shtml Article: Writing Considerations for ELLs 

    http://www.alliance.brown.edu/tdl/elemlit/readingk3.shtml Article: Reading Considerations K-3 for ELLs 

    http://www.alliance.brown.edu/tdl/elemlit/reading46.shtml  Article: Reading Considerations 4-6 for ELLs

    http://www.alliance.brown.edu/tdl/elemlit/orallanguage.shtml#litreview  Article: Considerations for Oral Language Development 

    http://knowledgeloom.org/practices3.jsp?location=1&bpinterid=1110&spotlightid=1110  Article: What is Culturally responsive teaching 

    http://www.colorincolorado.org/article/33049 Article: Supporting ELLs in a Mainstream Classroom 

    http://www.siopinstitute.net/classroom.html SIOP Model Lesson Plan 

  • Is there any analogous protein for TGFB1 to detect in plasma through ELISA?

    I dont have kit but rather have the antibodies and OPD to detect my samples. But problem does arise based on the standard samples. Any possible outcome apart from kit based assay. Yes making recombinant protein is quite a solution but would like to know any possibilities of an analogous protein for TGFB1 standard assay 

    Saumyadip Sarkar · Institute of Life Sciences

    Dear Bassem

    Yes recombinant protein is important and will go for that.

    Dear Prakash

    Yes recombinant protein is required. What if recombinant protein is made using complement cells? Would that be cheap and efficient?

  • Sushil Kumar Sharma asked a question in Social Media:
    Do Social Media have any influence on society or its just an activity of a few technosavy geeks ?

    Do Social Media have any influence on society or its just an activity of a few technosavy geeks ? 

    A few people keep posting their view / opinions on the social media. 

    Most of the time they are unaware of ground realities. 

    Do these people really have any influence over society or its just an assumption?

  • John F Black added an answer in Fiber Optics:
    Is it possible to send electrical power through a fiber optics cable?

    Is it possible to send electrical power through fiber optics cable??

    John F Black · Start-up Company

    Yes - JDSU has this http://www.jdsu.com/en-us/power-over-fiber/Pages/default.aspx#.VJXXPl4DA 

  • Can anybody tell me how to determine Faraday efficiency of alkaline and Direct methanol fuel cells?

    Faraday efficiency is defined as ratio of observed cell current to estimated theoretical current. I am just wondering how to determine the theoretical current for for given gas by using Faraday's law.

  • Can anyone help me with the calculation of temporal patterns in an enteric methane emissions trial?

    How can I unify data from one year of measurements without making an average of averages?

    We were informed that data collection was carried out approximately one week in each of the seasons of one year.

    My experiment was done in a randomized block design with three replications. Is there a stochastic pattern that is likely to mess up this temporal analysis?

    Any feedback is welcome!

    Susantha Jayasundara · University of Guelph

    Dear Raphael,

    While searching for some literature to derive enteric CH4 emission factors for grazing beef cattle, I came across on following papers that might be useful for your question.
    Lassey, K.R., Pinares-Pati˜nob, C.S., Martina, J.R., Molanob, G. And McMillan, A.M.S. (2011) Enteric methane emission rates determined by the SF6 tracer technique: Temporal patterns and averaging periods. Animal Feed Science and Technology 166– 167 (2011) 183– 191.
    McCaughey, W. P., Wittenberg, K. and Corrigan, D. 1999. Impact of pasture type on methane production by lactating beef cows. Can. J. Anim. Sci. 79: 221–226. (attached below)

    I did not attached Lassey et al. 2011 paper since I am not sure about copyright issues. If you cannot access it, please let me know. I will send a PDF copy.

    I have not involved in measuring enteric CH4 emissions, but have read few papers as part estimating GHG intensity (carbon footprint) of milk and meat from cattle. Your question is an interesting one. From what I have read, I think grazing season may have an effect on enteric methane production (g CH4/kg DMI) since pasture quality seems to vary depending on the season (e.g. spring vs. summer).

    Susantha.