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  • Hersh Khizir added an answer in Spray Pyrolysis:
    Does the thin film thickness effect optical band gab?

    For during my work I observed that effect of the thickness on the band gap of Zn0.2Cd0.8S films decreases with the increase of the film thickness from 260 nm to 480 nm?

    Hersh Khizir

    Yes, This decrease of band gap may be attributed to the presence of unstructured defects, which increase the density of localized states in the band gap and consequently decrease the energy gap

    thanks for all

  • Eyad Abushandi added an answer in Rainfall Simulation:
    How can doing a comparison between TRMM and GSMAP rainfall datasets without any ground data?

    I need to know a method to compare between TRMM and GSMAP in any area without any information about ground data.

    Eyad Abushandi

    In my opinion, having ground truthing dataset is a must for the two products you mentioned. Saying no ground data for a particular catchment (hourly, daily, or even monthly) is not fully justified. Instead, you could find limited rainfall records to be optimized for your case. Alternatively, you could find a similar climatic zone (e.g. arid) which have enough record and use it for your purpose.

    However, plotting TRMM and GSMAP or finding correlations will give you a great idea on the behavior of the two against each other but not representing the conditions on the ground.

    Good luck

  • Ljubomir Jacić added an answer in Information Security:
    What is information security?

    Dear collegues. Your answer is highly appreciated. I think the points that you mentioned, have been prolific for me and many of RG members.

    Information security - the state of preservation of information resources and protection of the legitimate rights of the individual and society in the information sphere. Information Security - is the process of ensuring the confidentiality, integrity and availability of information.

    With kind regards, Shafagat

    Ljubomir Jacić

    Dear @Shafagat, this resource might be very interesting for the followers of this thread, as we do use cloud services like Dropbox, Googl Drive...

    Three ways encryption can safeguard your cloud files!

    "Cloud file storage is one of the wonders of the modern world.

    By storing your files in a cloud-based datacenter, you have access to them anytime and anywhere--as long as you have an internet connection. And letting someone else run that datacenter means you don't have to worry about the cost or complexity of running your own file servers with remote access.

    But putting your files in the cloud also means putting your trust in a cloud provider.

    The downside of cloud storage is that it represents yet another way for outsiders to attack your organization's intellectual assets. If you manage those assets for a law firm, a government contractor, or a company in an industry that's highly regulated (such as healthcare or financial services), you have every right to be worried about cloud file storage.

    End-to-end encryption protects you from bad guys who might try to intercept files in transit. But those files can be at significant risk when they're sitting in the cloud. Those "at rest" files are vulnerable to theft by a rogue employee, someone working on behalf of foreign governments, or unscrupulous competitors. They're also at risk if someone shows up at the cloud provider's office with a subpoena.

    The solution is "zero-knowledge" encryption, where you (and only you) hold the encryption keys. In that configuration, the cloud provider (or someone who succeeds in breaking into its servers) sees only encrypted files, with no way to decrypt them..."

    The second link bring the readers to A roundup of cybersecurity predictions for 2016!

    + 1 more attachment

  • Nils Wagner added an answer in Structural Mechanics:
    COMSOL Rotating Machinery model?

    I am trying to simulate a water turbine with rotating blades and a stationary duct around it, using the COMSOL Rotating Machinery module. Can anyone explain how to define the fluid domain and the rotating region? Thank you.

    Nils Wagner

    Regardless of the software, the matrices are time variant in your case.

    However, if you neglect the non-rotating part (i.e. stationary duct) you might use a co-rotating coordinate system for your cyclic symmetric water turbine.

  • G. G. J. Ernst added an answer in Ash aggregation:
    Has anyone managed to make fully spherical dense ash aggregates in the lab ?

    Hello everyone,

    My question relates to ash aggregation and so-called accretionary lapilli (dense ash aggreegates).

    These have been documented from fieldwork by various researchers including Sigurdur Thorarinsson, Jim Moore, Hans Schmincke, Ralf Schumacher, Jennie Gilbert and Steve Lane, Mauro Rosi, Mike James, Steve Self, Bill Rose, Adam Durant, Costanza Bonadonna....

    In a milestone study, Mike James studied how loose and low density ash aggregates can be made in the lab, illustrating the crucial role of electrostatic attraction in the making of those (matching some "field" observations by George Walker, Bill Rose,  Sorem 1982, Jennie Gilbert and Steve Lane 1991, etc...).

    In another milestone study, Ralf Schumacher (1991) (Hans Schmincke Group) made some dense roundish ash aggregates in a rotating pan where ash and water were mixed (ie. in the lab).

    In yet another milestone study, Jennie Gilbert and Steve Lane (BV, 1994) managed to make accretionary lapilli in a vertical Wind tunnel in the lab. These were not fully spherical though. They were sort of up to half-spherical. They could only make fully spherical acc-laps if they first introduced (polystyrene) spheres in the wind-tunnel so that ash would accrete around it.

    Durant et al (JGR, 2008) illustrated  that freezing was essential in the formation of fully sub-spherical dense ash agggregates; they mostly focused on ice nucleation temperature measurements on different sort of ash though. However, aggregation of ash in the lab was not from a suspension in a cloud, in the lab.

    I am wondering if anyone actually succeeded yet in making fully near-spherical (or  spheroïdal/ellipsoïdal) dense ash aggreagates (ie. accretionary lapilli) in a wind tunnel in the lab ?

    Many thanks for any information on this.

    Best wishes and greetings,


    G. G. J. Ernst

    Hello Alexa, Ulli, Volker and everyone,

    Alexa, thank you for your suggestions and passing on the PDFs of your papers. As George Walker would have said, I believe, these are very fine papers because the work is anchored on a very large amount of fundamental systematic and systemic observations and measurements, ie. providing significant constraints for inverse modelling. Such studies are not so common so that it seems to me that they are particularly valuable and insightful. George, like Sherlock Holmes, never ignored any clue, and this is why such an approach can ultimately lead one to be left with only one possible model admissible with all the data collected from all possible angles.

    I think that there is some confusion about acclaps in the sense that they can form in at least 3 different contexts and that we often see them in deposits the origin of which is not always 100% clear in publications.

    1. One context is dense fluidized pyroclastic density currents. In such a context, rapid steam (or water if PDC is submarine one fluidized by seawater) streaming up through degassing channels can lead to the formation of some very large accretionary balls around a crystal or lithic (Ulli's experiments are also more pertinent to investigate those). It is not clear what may be the maximum size limit of these but one may readily imagine that it is degassing channel width. One may get insights into these by revisiting the milestone experiments by Colin (Colin Wilson) on fluidization of pyroclastic flow material and Colin or Steve Self or Richard Brown have seen/reported numerous examples of these in classic PDC deposits from New Zealand (Taupo, Oruanui...), the Philippines (eg. Taal) or PDC deposits from Tenerife. If I recall right, Bill Rose and friends have also seen good examples of those in PDC deposits from El Salvador (Ilopango ?).

    A key point about these is that they do not fall through the air or experience recycling within eruption columns (eg. Ernst et al 1996, JGR) before leaving the umbrella base or eruption column side to then fall for say 10+ km to the ground. Of course, it seems likely that some airfall acclaps can also fall through PDC deposits (eg. Rich Brown work at Tenerife).

    2. In the latter case (strictly airfall acclaps), there is just no way the acc-laps can grow to larger than the drop break-up limit, which for pure water is 6-8mm diameter (RA Houze, 1993, p80; Fig 3.6). Having an ash-filled drop does not affect the break-up limit very much based on a unpublished detailed study that Adam Durant and I conducted at Santorini on the US1 airfall deposits and which is quantitatively consistent with a wet accretion growth up to a break-up limit of 6mm (above such a limit size, probability of drop break-up soars exponentially rapidly so that 8mm ones formed purely by wet accretion are unlikely). So in the absence of freezing (and further growth by riming), airfall acclaps cannot exceed such a size (most of the acclaps observed by Costanza at SHV or those observed at Sakurajima in 1991 by Jenni Gilbert and Steve Lane typically do not exceeed this size of 6-7mm or so). Again, Ulli's expts at LMU can provide insights on growth and binding of acacclaps before freezing sets in.

    If one produces SEM High Resolution maps of complete acclaps from such a context, all qualitative and quantitative parameters are consistent with further growth by accretion of ash-filled supercooled drops (with a characteristic size of 1-3mm or so; again this is constrained by the drop break-up limit).

    I have made systematic and systemic observations of such acclaps and compared them with hailstones and there is little doubt that these acclaps form as volcanogenic hailstones. 

    During hailstone fall, the stones undergo partial melting so that the largest balls may not melt due to rapid fall (10-30m/s say) but as they are brittle solids some will break upon impact (as in pumice breakage)...the majority of smaller balls melt and will produce mud rain but as partial melting is a stochastic process not all the balls will have melted, most will have partially melted and reverted to a partially frozen and partially ash-filled liquid drop like state so that upon impact all intermediates are observed between splashing (to make up the matrix of the acclap tuff bed), plastic deformation of a soft ball or brittle cracking or no breakage at all (soft landing upon mud-rain matrix made up of those acclaps that have melted before reaching the ground or would have splashed upon landing).

    So the field association of all these types of features can indicate that one is dealing with airfall acclaps and not with PDC acclaps for example.  As these beds are dominantly mud-rain beds, slurry, slumping and secondary flood or lahar  erosion channels will also be seen, especially in near-vent/proximal deposits.

    Further work on such airfall acclaps also leads to a quantitative relationship between maximum acclap size in a given acclap horizon and eruption column height which seems to be as helpful as the Carey and Sparks 1986 method to reconstruct Ht from deposit characteristics (unpublished data). This is great for phreatoplinian or phreatosubplinian past deposits to reconstruct Ht as these typically do not allow to apply the CS86 method and one only have thickness decay data to inverse model (eg. Bonadonna et al 1998).

    For airfall  acclaps, the larger they are the higher column height; clearly this does not extend to the case of acclaps that form within degassing pipes in PDC deposits in a completely different way.

    For airfall acclaps, the more severe the thunderstorm generated by the eruption (in this case, the eruption column is at the same time a severe thunderstorm), the more numerous the acclap horizons accumulate in rapid succession. In severe storms, numerous hailfall events occur whereas your small normal thunderstorm will only produce a single horizon of hailstones, perhaps 2 (this is also related to the lifetime of the thunderstorm which is short, but significantly  longer for a severe storm). So one expectation is that a sustained phreato(sub)plinian eruption may produce numerous acclap horizons in rapid succession whereas a weaker or short-lived event may produce a single acclap horizon per eruption burst event (eg. vulcanian).

    3. A third context is that of eruptions producing maar-tuff-ring-tuff cone associations where large clast accumulating on a near vent ring avalanche into a slurry filling the vent (eg. see Pete Kokelaar; Jim Moore, Volker Lorenz). Multiple ejection-recycling -ejection-recycling into the vent (Surtseyan style eruptions) can form splendid armoured lapilli textures. Some great examples from Irazú 1963-65, Surtsey 1965 or so for example (classic papers by Guillermo Alvarado, and by Volker Lorenz for example). I am not saying that some of the other types were not also observed at Surtsey for example....they were: eruption plumes were also generated there....some acclaps were just like the US1 airfall acclaps (based on S Thorarinsson and by Jim Moore observations for example).

    Finally, type 2, the partially melting frozen airfall acclap balls often fall not through clean air but through a lower air column filled with fine (most of it 20-40 microns) ash elutriated from base surges or denser PDC flows. Hence the last accreted ash layer on a falling acclap often  results from outer layer partial melting, shedding of most of that water due to shear during fast fall and size-selective wet accretion of very fine elutriated ash into an outer typically very thin water film (thickness of order of 1-2mm). These observations are for example consistent with the unpublished US1 study at Santorini.

    Hoping this may help a little. and with comparing to your own observations and measurements relating to formation of dense ash aggregates (ie. acclaps).

    Best wishes and kindest regards to all,


  • Yonggang Wang added an answer in Repeated Measures:
    How can we use a repeated measured Anova to examine the effects of driving time and age on driver’s visual behaviors?

    We have collected drivers eye moment data (four groups: ‘<30’, 7drivers; ’30-40’, 14 drivers; ’40-50’, 10drivers; ‘>50’, 5 drivers) after 2, 3 and 4h continuous driving. I have attached a visual variable.

    Yonggang Wang
    Dear Bettina, thank you very much for your answer, but I do not konw clearly how to prepare the input data in SPSS. Taking the data of '<30' drivers for example, should I use the average value of 7 drivers or take each driver's data as a row?
  • Nithyanandan Manickam added an answer in Aquatic Ecology:
    Pipe fish from Arabian Gulf


    Can anyone help me with the identification of these pipe fishes collected in Kuwait, Arabian Gulf.

    Best Regards,

    M. Nithyanandan

    + 1 more attachment

    Nithyanandan Manickam

    Dear Dr. Fareed,

    I collected the specimen and preserved it in absolute alcohol. Total length is 4.7cm.

    Best Regards,


  • Richard Omoregie asked a question in Bioedit Software:
    Using Bioedit software, which do I delete in the alligned fotward and reverse sequences - the coloured identical or uncoloured sequences?

    I am trying to edit my sequences before performing a BLASTn

  • Hossein Soleimani added an answer in Copolymerization:
    If the percent of third monomer in terpolymer be very low is it possible using copolymerization kinetics?

    Recation follows copolymer kinetic or no?

    Hossein Soleimani

    dr. Leonid V Vladimirov 

    mma/aa have 0.4 and 1.8 are not very big!?

  • Tim Woolliscroft asked a question in Academic Writing:
    Writing in active or passive voice - does epistomology matter ?

    I am currently working on a PhD and have been encouraged to write in the passive voice, I know this is not uncommon.  There however seems to be some tension between the subjective epistemology and reflexivity in the methodology and this approach to writing.  Given this I feel that writing in the first person would be more authentic.  Am I being naïve or are there arguments in favour of academic writing in the first person.  Also is it true that it is difficult to get articles published if they are written in the first person?

    The discipline is business / organisational development.  Any advice or recommended research on this area would be very much appreciated. 

  • Nihad Ayub added an answer in Physical Activity:
    Does the Physical Activity Vital Sign improve patient physical activity levels?

    is there research for the question " does the Exercise Vital Sign improve patient's level of activity?"

    Nihad Ayub

    Any exercise should be depending on the level of the individual, so the patient must be exercise by him down and must be adequately with his illness and should be placed Testing tribal patient

  • Alfredo Pereira Junior 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.

    Alfredo Pereira Junior

    Dear Arnold, considering that feelings are always conscious and that subjectivity has a large unconscious basis (Freud), I cannot agree that subjectivity is sufficient to produce or explain feeling. "Feeling" for me is a precise term to denote conscious expreinces or the "what it is like to be". Subjectivity is an ambiguous term that does not help much to a scientific approach of consciousness.

  • Han Ping Fung added an answer in Fitness:
    What is your definition of 'fitness'?

    It's all in the question


    Han Ping Fung

    What is your definition of 'fitness'?

    To me fitness is defined as fit for the purpose whether the purpose is from the perspective of physical, mental, emotional, spiritual etc.

  • Saranya Bharathi added an answer in Accelerometer:
    Has anyone attempted Principal component analysis on time series and acceleration data(ie. data from accelerometer)?

    Has anyone attempted Principal component analysis on time series and acceleration data(ie. data from accelerometer and sensors) and tried compressing it as well as regenerating back the data with minimum error?

    I wanted to know if this is possible using PCA.

    Saranya Bharathi

    Can you suggest some methods for processing data from sensor?

  • Hossein Soleimani added an answer in Images:
    Can entropy of contrast enhanced image be greater than the original image?

    Can histogram equalization increase the entropy of an image?

    Hossein Soleimani

    Yes. when you equalize the histogram,  fill some empty bins in histogram.for example, the original image may not have intensity greater than 240, while after histogram equalization, the resulted image has intensity almost in all bins. this means that you have a histogram(or probability distribution function) in which intensities are distributed uni-formally and  as a result the entropy( uncertainty) will increase.

  • Fernando Mancebo Rodriguez added an answer in Heat Transfer:
    What is the speed of heat transfer between elements in a system or between two systems?

    Heat transfer by thermal radiation

    All bodies radiate energy in the form of photons moving in a random direction, with random phase and frequency. When radiated photons reach another surface, they may either be absorbed, reflected or transmitted.


    Every system emits heat energy; in fact a system works on itself continuously that is positive work on the environment. Let's name it the "Inherent power of system". So, every system has an inherent power that is greater than zero P>0.

    We give heat to a system, in fact k photons with speed c enter the system, and particles of system absorb them. In a real environment the inherent power of a system cannot be zero, even in space, because there is cosmic background radiation in space.


    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: In classical mechanics, time is something that passes uniformly regardless of whatever happens in the world. For this reason Newton spoke of absolute space and absolute time. On the other hand, Einstein's Special Theory of Relativity predicted that time does not flow at a fixed rate: moving clocks appear to tick more slowly relative to their stationary counterparts. Quantum mechanics does not neglect the time either. In standard model, photon does not experience time. Some new theories suggest that time does not exist at the quantum level. The study of the quantum universe shows us that time does not exist. It shows us that time is a function of relativity only and exists relative to some arbitrary point of reference [1]. Whatever else may be said about time, one thing is certain. It defies definition. The best we can say is that we all know what time is, intuitively. The Seventh Edition of Webster's Collegiate Dictionary tells us that time is "the measured or measurable period during which an action, process, or condition exists or continues." Of course, what the lexicographer has done here is to tell us that time is defined by its measurement and that measurement is of a period during which something occurs. He has not told us what time really is [2]. In fact it is the definition of a clock. What is the nature of physical time, really? In this paper, I have tried to answer this question.
      Full-text · Article · Aug 2015
    Fernando Mancebo Rodriguez

    I think these parameters (molecular movement, temperature, heat and speed of transmission of heat) don’t follow a strict and general interrelation among elements because each element or type of molecules should have different behavior regarding to heat.
    On the other hand, I think heat represents a modality of potential energy, but not a direct inertial energy to be measured directly with relation to momentums.
    Off course, I can be wrong surely.

  • Alfredo Pereira Junior added an answer in God:
    What is the origin of the laws and principles of nature?

    More precisely, "what is the origin of the regularities in nature which are represented (or purported to be represented) in our various recognized or accepted laws and principles regarding nature and natural events?" (this is H.G. Callaway's formulation of the original question). Such a philosophical question should be of interest to all scientists. 

    In classical philosophy, there are two ways of answering it:

    a) Looking for an explanation outside nature. The concept of a transcendent God, the creator of nature and its order, explicitly appeared in Thomas Aquinae (the world comes from God and returns to God), Modern philosophers and scientists. It reappeared in the Contemporary epoch as a refusal of Darwinism, and/or related to some interpretations of Quantum Theory;

    b) Looking for an explanation inside nature. Nature itself, being composed of both Form and Matter (Aristotle´s Hylomorphism) produces its order, in a process that has been currently called "self-organizing". In this view, God is not the creator of Nature, but - as in Aristotle´s concept of a First Mover - an ideal of perfection projected by natural beings.

    It is clear that in spite of Aquinae´s affiliation with Aristotle, their philosophies are in opposite position in regard to the question about the origin of nature´s order. 

    Spinoza tried to conciliate both approaches, by equating God and Nature. In this case, God is not conceived as a transcendent being who creates Nature from nothingness, but as a being who is somehow immanent to Nature.

    Plato, before Aristotle, presented a combined solution, assuming both the autonomy of natural principles (Ideas) and a Demiurge who prompts the manifestation of the principles into the world of appearances.

    There is a possible third alternative, advanced by Kant in his cognitive approach to philosophical issues: to assume that laws and principles of nature are 'a priori' forms that the human mind imposes to sensory "matter". However, this alternative is actually reducible to the others. Cognitive forms should be natural or created by God (both possibilities are compatible in Spinoza's approach). For instance, the Piagetian version of Kantism assumes that these forms are biological, deriving from processes of interaction with the physical and social environment - therefore, he was committed to the self-organizing view.

    Alfredo Pereira Junior

    Dear Louis,

    I appreciate your explicit assumption of a Creator God, although - as you know - I do not share this belief.

    There are many controversies about Aristotle's concepts of God, Formal and Final causes, and I think there is no explicit concept of consciousness in his books.

    My view is that the Final Cause (the First Mover, later in history related to the Christian concept of God) is a product of human mental activity. More precisely, the First Mover is the object of desire of human minds in search of perfection. Therefore, for Aristotle God would not be the creator of reality, but the desired destiny of the world if ethical actions are successful. 

  • Rajinder Singh Brar added an answer in Vitamin D Deficiency:
    Is there any survey or research world wide that reflects co relation of vitamin D deficiency and number of children?

    Is there any survey or research world wide that reflects co relation of vitamin D deficiency and number of children?

    Rajinder Singh Brar

    Vitamin D deficiency is prevalent among subfertile women.

    Gynecol Endocrinol. 2015

  • Przemysław Tomczyk added an answer in Customer Relationship Management:
    Are there any available data sets that can be used on E-CRM ?

    Hello everyone, I look for data sets on E-CRM. I want to test my framework for improving data quality on E-CRM.

    Przemysław Tomczyk

    I recommend a contact with an enterprise, which is marketing automation system user and propose a cooperation in the field of customer data analysis. If you have a database, you can modify it and perform simulations according to your needs. The profile of the enterprise should be consistent with your research objectives, of course.

  • Najamuddin Najamuddin asked a question in Fishing Technology:
    Why sustainable fishing technology are very difficult to implement in Indonesia ?

    In order to answer this question, need many research such as

    - Evaluation of all fishing gear design and their selectivity

    - Evaluation of fisheries resources around fishermen village

  • Armand Seraphin Nkwescheu added an answer in Public Health:
    Should people from Zikka virus affected countries be initially quarantined??

    Zikka virus is spreading across south america and the US and this is not a good sign for global public health. During the ebola outbreak in 2014 people coming from countries where the ebola outbreak occurred were isolated until cleared for the virus. should people from Zikka virus affected countries be initially quarantine??

    Armand Seraphin Nkwescheu

    Just as the former responders, i will not advocate for the quarantine policy. Quarantine should be a least a partial solution to  a problem. In the case of Zika virus i don't see how this option could help. The NIH of USA has launched a call for research for a vaccine and certainly this will be a way out.

  • Stefano Quattrini added an answer in Gravitational Field:
    Is the clock rate of free falling clocks the same?

    In a gravitational field of a homogeneous spherical mass M, a sufficiently small mass B, compared to M,  is left free in the gravitational field of M at a certain distance H from the center of mass, outside his surface. B gains speed, relative to the center of mass M, because of gravitational attraction. Many small objects like B free fall from different heights or from the same height at different instants.

    Every object has an atomic clock on board. Would these clocks have the same clock-rates during the free fall?

    A reference, master clock has to be adopted, otherwise the problem is ill posed. Clock-rates are refererred to an atomic clock on the surface of M for example (negligible M  rotation speed).

    The time elapsed for each body to go from the same starting and ending point counted by the atomic clocks on board is certainly the same (UFF).

    Their clock rate should be different, in general, unless they start from the same position and instant. Not because  light takes less time to reach the closest, since they are in different positions, but  because there exists a  relation between the very small object and the massive object.

    I would like your opinion regarding this problem.

    Stefano Quattrini


    "They run at exactly the same rate. Yet, somehow, they become unsynchronised. Then, I am to believe that all clocks are subject to the same physics, regardless of differences in their proximity to a gravitating mass."

    infact there is an intrinsc contradiction. It seems that the oscillators  should behave in the same way but then they should not, since is argued that they went for different paths. I don't see different paths in gravitational time dilation, and there is no need to rejoin or move the clocks for the static positions, in order to spot their unsync.

  • Rajinder Singh Brar added an answer in Poultry:
    What are the possible ways to treat poultry litter wastes?

    How can we manage poultry litter for betterment of environment and agriculture?

    Rajinder Singh Brar

    Worth reading

    A Practical Guide for Composting Poultry Litterhttps://www.researchgate.net/post/What_are_the_possible_ways_to_treat_poultry_litter_wastes 

  • Darren Protulipac added an answer in Permeability:
    Permeability Coefficient (K)

    Hello, dear my colleagues
    I am working on my dissertation. My dissertation is about engineering geological study of a dam. About fifty percent works of dam are completed. Type of dam is Roller Compacted Concrete. The foundation abutment of dam was conducted grouting. Now, I want to analysis the seepage of dam. Please kindly let me know how can I find the permeability coefficient and which software are most comment for seepage analysis.
    Thanks and advance

    Darren Protulipac

    Suggest looking at the grout takes or rather injection rates. Use the higher w:c ratios to determine lugeon values - this will give you a starting point in your analysis. Assume this to be the equivalent hydraulic conductivity prior to grouting. You'll need to break the rock mass into similar lugeon zones. As per the grout curtain efficiency - you'll need to ascertain how the grouting was done, closure criteria and desired final permeabilty.

  • Jay Bergi added an answer in Bacterial Cell Culture:
    What is a need of adding base agar in Bioassay of Antibiotic?

    If we work with only top agar and prepared well in it and add antibiotic...Do we get result? or it is necessary to add first base agar and later top agar with bacterial culture?

    Jay Bergi
    The original method of bioassay was developed for penicillin (of course because it was the first antibiotic). Research on penicillin was pioneered at Oxford University and so here the first method was designed. This was done by Abraham and Chain in 1941.

    This original method didn't used two layers of agar.

    However many modifications of Abraham's Cylinder Plate method were proposed later. Most significant work was by SCHMIDT and MOYER. They presumably were the first to to suggest use of two layers in 1943.

    There are plenty of reasons to use two layers.
    1. They used different media for supporting growth (base) and to have sharp boundaries of zone of inhibition (top agar with more salts).

    2. On those days workers used to prepare large number of plates and it was common practice in their laboratory to prepare base agar 24 hrs earlier (probably to have uniformly dried plates) and add top agar for assay on next day.

    3. They were aware of many factors that influence size of the zone of inhibition and thus final result. One of these factors is depth of agar that increases/decreases diffusion of antibiotic solution and changing the diameter of zone. In order to standardise this they had a regular practice of having 22 ml of base agar prepared early overlaid with 3 ml of top agar on the day of assay.

    Original paper can be found on following link, a strongly recommended reading. :)

  • Ayman Ahmed added an answer in Entomology:
    Does anyone know a good place in Africa where I could still observe a good swarm of Anopheles gambiae mosquitoes in the wild?
    I am interested in the timing, sizes, variations in geographical location, and other aspects of swarms of Anopheles gambiae. My main reason for this is to observe first hand and verify some earlier observations and publications on this topic. I want to understand the sequence of events that define a swarm.
    Ayman Ahmed

    You can do that in any country with high density of mosquito of interest such as Sudan, Tanzania  .... etc.

  • Martin Kamprath added an answer in Technological Change:
    Do you know technology classifications or categories?

    I want to describe on a generall level how technological change impact on different technologies of an organization. I hope, there exist a kind of categorization schema for various kinds of technologies independently from any industry affiliation.

    Martin Kamprath

    Dear Aleksandr, thank you for your comment. I totally agree with you that the basis of all categorizations (typologies and taxonomies) is the criteria or indicator. And exactly in this direction aims my questions. What categories exist and which are their underlying criteria? As one major task of science is to study phenomena and categorization is one major element, I was wondering how other researchers operationalise such technological change e.g. in an industry. I mean we have plenty categories of resources or capabilities and dozens of categories for firms and their strategies. So, do we have categories of technologies, e.g. to compare changes in industries?

  • Ladi Sandeep Kumar asked a question in Hyperspectral Imaging:
    Can anyone suggest any useful link where we can get a survey on Hyperspectral image processing Processing in Agriculture.

    Research Scholars,Faculties

  • Alan P Newman added an answer in Water Quality:
    What are the impacts of cement industries on Waterbodies?

    i have searched lot through internet  regarding impact of cement industries on water quality, but not much information available, only pH and alkalinity changes. just i wanted to known any other effect on water quality.

    Alan P Newman


    Please remember that the cement industry uses a lot of fuel and in the UK at least this can include waste oils and other organic wastes. If I were investigating pollution from a cement plant I would be looking for such components in the storm water runoff.

    Also the minerals associated with limestone deposits such as lead ,zinc and cadmium sulphides.The metals can be released from stockpiles. Obviously not an issue if using shell as the source of calcium carbonate.


  • Sebastian Schmitt added an answer in Protein Purification:
    Isolation of highly reactive protein?

    Hello, I need some help from protein-purification experts out there.

    We are trying to isolate a protein suggested by a predicted amino acid sequence. This protein is believed to be highly reactive and expressed in low amounts in vivo. We are trying to study its expression in the natural system and we have antibodies designed to target this protein. We have tried a lot of things like immunoprecipitation and enrichment methods from crude homogenates and isolated a protein which seems to be recognized by one of our antibodies.

    However, after analysis from mass spec, it turns out that the isolated protein is NOT the protein we hoped for it to be. So I wonder if you have any suggestions as to where to restart again?? Should I look at transcription first? I would greatly appreciate your help.