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  • Saeed Noori asked a question in Monitoring:
    Domain control and monitor the performance of diesel What is ?

    Domain control and monitor the performance of diesel What is ?

  • Saeed Noori asked a question in Fuel:
    Classification engine generators in terms of fuel consumption What is ?

    Classification engine generators in terms of fuel consumption What is ?

  • Luis G. Castillo added an answer in Hydraulics:
    Does anyone know any CFD modeling software that can be used for hydraulic computation purpose?

    Does anyone know any CFD modeling software that can be used for hydraulic computation purpose?

    Luis G. Castillo · Universidad Politécnica de Cartagena

    HEC-RAS, Mike Mike 11 and 21 are not programs Computational Fluid Dynamics.

  • Isaac Mehboodi added an answer in FLUENT:
    How can I calculate inertial and viscous resistance coefficients in porous media?

    I want model flow through porous media by fluent.

    Isaac Mehboodi · Islamic Azad University, Science and Research

    hi dear

    tnx for all your advise

    i think  ergun equation use for gas flow through porous media but in my case i  want to model nano fluid through porous media so i understood from all of your comment  i can use thise(inertial resistance=0 and viscous resistance=1/a where a is permeability) for laminar flow through porous.is this correct?

  • Niranjan Biswal added an answer in Religion:
    Can we correlate science with religion?

    Science and religion...

    Niranjan Biswal · Technion - Israel Institute of Technology

    Agree with Miranda and Sudev

  • Louis Brassard added an answer in Foundations of Physics:
    Do the effects of mind on matter as demonstrated in the experiments of Radin et al (Physics essays 2012 & 2013) herald a new scientific paradigm ?

    This refers to the recent experiments of Radin et al :

    1) D. Radin, L. Michel, K. Galdamez, P. Wendland, R Rickenbach and A. Delorme
    Physics Essays, 25, 2, 157 (2012).
    2)  D. Radin, L. Michel, J. Johnston and A. Delorme, Physics Essays, 26, 4, 553 (2013).

    These experiments show that observers can affect the outcome of a double slit experiments as evidenced by a definite change in the interference pattern.

    It requires urgent attention from the scientific community, especially Physicists.

    If these observed effects are real, then we must have a scientific theory that can account for them.

    Louis Brassard ·

    Dear Jürg Martin Fröhlich ,

    Science is limited to provide models with some reference to aspects of the world we can measured. I am saying that Mind, Experience, Consciousness, Awareness  are not conceptually describable by such models.  We cannot and will never  come up with a concept of what is redness. If someone would never had eye, no knowledge about vision would give the person a clue about the experience of redness.  We can say a lot of thing about what are involve in colour vision and I studied this field for several years but none of it explain redness.  The robot I design to pick up mature tomatoes had no experience of redness whatesover although it was able to pick up tomotoes that you and me see/experience as red. We can even imagine and dream of red things.  Nothing in what we know about the body explain why we are aware and conscious.  

    I will now quote one of the best visual scientist of our time:

    ''Here is a basic experiment:
    Open your eyes in broad daylight, notice what happens.
    The result may hardly prove amazing to you:
    you are likely to see the scene in front of you,
    at least, when you are not blind, inattentive, hallucinating, and so forth. Yet
    this experimental result should appear amazing in view of the fact that science
    has no clue of how to account for it!
    Science can only repeat the long familiar story involving the physics of
    electromagnetic radiation and its interaction with matter, the optics of the
    eye, the neurophysiology of the brain, and so forth. Such stories allow you
    to understand causal connections between the scene in front of you, and electrochemical
    events inside you skull. This is by no means a minor feat, it took
    centuries of intellectual labor. So far so good. But beyond that anything else
    that might be said is mere mumbo jumbo to the honest scientist. The visual
    awareness of the scene in front of you is literally magick, in the sense of being
    beyond any (including future!) scientific understanding.'' jan koenderink


  • Ashwini Kumar Dubey added an answer in Endophytes:
    How can I purify and isolate antibiotic compounds?

    The antibiotic compound was observed from endophytic bacterial isolates isolated from Metroxylon sagu (sago palm)

    Ashwini Kumar Dubey · Pondicherry University

    Dear Irson Thurs Doria,

    I can give you details under following points,

    1. Grow your microorganism in suitable culture medium till the OD reach above 2.0 at 600 nm.

    2. Collect the culture supernatant and down concentrate it ten fold using rotary evaporator.

    3. Solvent extraction: Using organic solvents like acetone (ice cold), precipitate out high molecular weight compounds. Try for 40, 60, 80, 90 & 100 % acetone precipitation. Each fraction need to be screened for its activity. Generally the antibiotics are low molecular weight compounds and it would come in 80 or 90% supernatant.

    4. Remove the acetone form active fraction using rotary evaporator.

    5. The active fraction can be now passed to either ion exchange (cationic or anionic) or hydrophobic column (C18 or amberlite XAD-4 orXAD-16) followed by preparative HPLC.

  • Sarang Bhola added an answer in Business Management:
    Any scale for postgraduate (by research) students (management) performance?

    Looking for factors affecting postgraduate by research students performance. The respondent is business/management postgraduate students. Any measuring scale?

    Thank you in advance

    Sarang Bhola · Karmaveer Bhaurao Patil Institute of Management Studies and Research, Satara

    Dear Sir,

    Output of research take its own time, hence performance of student (research scholar) should be measured  owing to short run and long run perspectives. in long run quality of research publications and its utility to respective stakeholders  is performance measurement. in short run quality of work done at excelling stages of research be measured by students and research supervisor. the average ratings of student and supervisor can be termed as performance measurement.

  • Anurupa Goswami asked a question in Protein Structure:
    What are softwares to predict tertiary and quarternary protein structure from a sequence and how to validate it?

    I have the sequence of a protein and I want to predict the structure. Any suggestions

  • Abdelwadod Khiery asked a question in Lithium Chloride:
    Please, Dose of lithium chloride will affecte on brain tissues of the rats

    How  make dose of lithium Chloride for rats by body weight to effecte on the Brain >there is some equation  like Exraplaztion  or Allometric Scalling can do this but  I fail to do by it >any body can helpe me ?

  • Shivam Mishra asked a question in Box Plot:
    How to order a box-plot graph in descending order on y-axis?

    I wish to order my box plot graph in descending order on the Y-Axis. I am using PRISM 6.0 but dont know how to do it that. Any help is very welcome for this.

    Please see pic attached 

  • Anoop Kumar Srivastava added an answer in Plant Growth:
    What is the importance of calcium nitrate in plant growth ?

    i would like to know the importance of calcium nitrate to plant . i know that this fertilizer is  made up of two nutrients : nitrate and soluble calcium . a biochimical response should be appreciated  to know how green plants uses these two nutrients . thanks.

    Anoop Kumar Srivastava · Central Citrus Research Institute ( Formerly National Research Centre for Citrus )

    Thanks Maher. Another very intriguing issue regarding calcium nutrition of plant , i missed in my earlier communication , is the tripartite relation between calcium , magnesium and potassium . Potassium on one hand , is balanced by concentration of calcium and magnesium on the other hand . This relation operates at both the levels, soil and in plants system. Soils rich in exchangeable-K, especially in those soils having illitic mineralogy , excess of k has to be balanced by addition application of Ca plus Mg , if the maximum response of these nutrients has to be harnessed. 

  • Sarang Bhola added an answer in Leadership Research:
    How can I measure leadership style?

    what instruments and measures exist to measure the leadership style ? And what would you recommend ?

    Sarang Bhola · Karmaveer Bhaurao Patil Institute of Management Studies and Research, Satara

    Leadership Models proposed by Bass and Yukl are good enough to measure leadership styles.

    Bass BM, Avolio BJ (1990). Developing transformational leadership: 1992 and beyond. J. Eur. Ind. Train., 14: 21-27.

    Bass, B. (1990), Bass &Stogdill's Handbook of Leadership: Theory Research and Managerial Applications, 3rd ed., Free Press, New York, NY, .

    Bass, B.M. (1985). Leadership and Performance Beyond Expectations. New York: Free Press.

    Yukl G (2002). Leadership in Organizations. 5th Edition, Upper SaddleRiver, New Jersey, USA.

    Yukl G (2010). Leadership in Organizations, 7th Edition, New Jersey:Pearson Education.

    Yukl, G. (1989). Leadership in organizations,London, Prentice-Hall.

    Yukl, G. (1994). Leadership in organizations (3rd ed), Upper Saddle River, N.J.: Prentice-Hall.

    Yukl, G.A. (2001). Leadership in Organizations (5th Edition). Englewood Cliffs, N.J.:Prentice-Hall, Inc.

    we had made an attempt to use the said models to measure leadership styles. articles are made available on my ID at research gate.

  • Deepankar Ashish asked a question in TILLING:
    Can anyone tell me or provide paper about highest achieved strength of concrete till date?

    Can anyone tell me or provide paper about highest achieved strength of concrete till date?

  • Sivanathan Sivanathan asked a question in Swarm Robotics:
    What are the methods used for map merging in swarm robotics?

    In multirobot system, every robot(agent) explores the environment independently and creates the map of environment wherever it traversed across. Maps created by multiple robots are then merged to get the map of overall environment. To do this map-merging, I believe there are various methods used. I would appreciate if somebody explains these methods and merits and demerits of each method.

  • Martin Schulz added an answer in PVsyst:
    How can we calculate the least spacing distance between PV modules to minimize shading effects?

    I have read many papers about shading and many textbooks and handbooks in PV systems. No reference has ever given a clear procedure for such a problem. Are there any rules of thumb for this?

    Martin Schulz · Infineon Technologies

    Dear Al-Motasem,

    there is so little written about it, because it is a basic geometric task to be fulfilled.

    Input parameters are the geographic position and the PV-Module dimension.
    If you know both, it is simply calculating the height of the triangle formed by the PV-cell and the length of the shadow it throws.

    This paper:


    published 1998, has a drawing on the very first page to explain the correlation. I'm sorry it's in German only but math and figures should be helpful.

  • Daniel B Botkin added an answer in Forest:
    How the forest ecosystem related to climate change?

    Forest are the main source of the earth which support to protect biosphere. How the climate change effects the natural forest ecosystem and how can we predict impacts and mitigate those impacts? 

    Daniel B Botkin · University of Miami

    See the following publications which have to do with your question and have been the focus of my research over decades:

    Books and Software:
    Botkin, D.B., 1993, Forest Dynamics: An Ecological Model, Oxford University Press.

    Botkin, D.B.,2015 JABOWA -IV (Software and manual). Can be obtained from my website www.danielbbotkin.com

    Botkin, D.B., 2010, Powering The Future: A Scientist’s Guide to Energy Independence (FT Press, Upper Saddle River, NJ).

    Botkin, D. B., 2012, The Moon in the Nautilus Shell: Discordant Harmonies Reconsidered (Oxford University Press, New York, hardback and ebook, September 14, 2012). (One of 5 finalist in the 2013 USA Best Book Awards (Science))


    Botkin, D.B., J.F. Janak and J.R. Wallis, 1973, Estimating the effects of carbon fertilization on forest composition by ecosystem simulation, pp. 328 - 344, In: G.M. Woodwell and E.V. Pecan, eds., Carbon and the Biosphere, Brookhaven National Laboratory Symposium No. 24, Technical Information Center, U.S.A.E.C., Oak Ridge, TN.

    Botkin, D.B., 1977, Forests, lakes and the anthropogenic production of carbon dioxide, BioScience 27: 325 - 331.

    Woodwell, G.M., R.H. Whittaker, W.A. Reiners, G.E. Likens, C.A.S. Hall, C.C. Delwiche, and D.B. Botkin, 1978, The biota and the world carbon budget, Science 199: 141 - 146.

    Botkin, D.B, 1979, Status of ecological theory, pp. 101 - 102, In: M,N, Dastoor, L, Margulis, and K,H, Nealson, eds., Interaction of the Biota with the Atmosphere and Sediments, Final Report of NASA Workshop on Global Ecology, held October 18 - 20, 1979.

    Botkin , D B. B. Maguire, B. Moore, III, H.J. Morowitz and L.B. Slobodkin, 1979, Ecology, pp 105-121 in N. S. Bricker (ed.), Life Beyond the Earth's Environment: The biology of living organisms in space, NAS Space Science Board, NAS Washington, D. C. :105-121.

    Ralston, Charles W.; G. M. Woodwell; R. H. Whittaker; W. A. Reiners; G. E. Likens; C. C. Delwiche; D. B. Botkin 1979 Where has all the carbon gone? Science, New Series, Vol. 204, No. 4399. (Jun. 22, 1979), pp. 1345-1346.

    Botkin, D.B. (ed.) 1980. Life from a Planetary Perspective: Fundamental Issues in Global Ecology. Final report NASA Grant NASW-3392. 49 pp.

    Botkin, D.B. (ed.), 1980, Life from a Planetary Perspective: Fundamental Issues in Global Ecology, Final report NASA Grant NASW-3392, 49 pp.

    Botkin, D. B. and E. V. Pecan (eds.), 1982, Habitability of the Earth: Land-Air Interactions. Report to NASA, 32pp.

    Botkin, D.B., 1982, Can there be a theory of global ecology? J. of Theor. Biol. 96: 95 - 98.

    Botkin, D.B. (ed.) 1980. Life from a Planetary Perspective: Fundamental Issues in Global Ecology. Final report NASA Grant NASW-3392. 49 pp.

    Botkin, D.B., 1984, The Biosphere: The New Aerospace Engineering Challenge. Aerospace America, July 1984, p. 73-75.

    Botkin, D.B. and S.W. Running, 1984, Role of Vegetation in the Biosphere, Purdue University Machine Processing of Remotely Sensed Data (Symposium), pp. 326-332.

    Davis, M. B. and D. B. Botkin, 1985, Sensitivity of the Cool--Temperate Forests and Their Fossil Pollen to Rapid Climatic Change, Quaternary Research 23:327-340.

    Botkin, D. B., 1985, The Need for A Science of The Biosphere, Interdisciplinary Science Reviews,10(3):267-278.

    Bretherton, F.P., D. J. Baker, D.B.Botkin, K.C.A.Burke, M. Chahine, J.A. Dutton, L.A. Fisk, N.W.Hinners, D.A. Landgrebe, J.J. McCarthy, B. Moore, R.G. Prinn, C.B. Raleight, WV.H.Reis, W.F. Wee,s, P.J. Zinke, 1986, Earth Systems Science: A Program for Global Change, NASA Earth Systems Science Committee of the NASA Advisory Council, Washington, D. C. 48pp + supplements.

    Botkin, D. B. 1986 (ed.), Remote Sensing of the Biosphere, National Academy of Sciences, Washington, D.C.

    Botkin, D.B., 1989, "Science and The Global Environment," pp. 3 - 14 (Chapter 1) in
    Botkin, D.B., M. Caswell, J.E.Estes, A.Orio (eds) Man's Role in Changing The Global Environment:Perspectives on Human Involvement, Academic Press, Boston.

    Stolz, J.F. Botkin, D.B. and M.N.Dastoor, 1989, "The Integral Biosphere", pp. 31-49 (Chapter 3) in M. B. Rambler and L. Margulis (eds.), Global Ecology:Towards a Science of the Biosphere , Academic Press Pub., Boston.

    Botkin, D. B., R. A. Nisbet, and T. E. Reynales, 1989, "Effects of Climate Change on Forests of the Great Lake States, pp.2-1 to 2-31 in The Potential Effects of Global Climate Change on the United States, J. B. Smith and D. A. Tirpak (eds.) U. S. Environmental Protection Agency, Washington, D. C., EPA -203-05-89-0.

    Botkin, D. B. and R. A. Nisbet, 1990, Response of Forests to Global Warming and CO2 Fertilization, Report to EPA.

    Botkin, D. B., D. A. Woodby, and R. A. Nisbet, 1991, Kirtland's Warbler Habitats: A Possible Early Indicator of Climatic Warming, Biological Conservation 56 (1): 63-78.

    Botkin, D. B., 1991, Global Warming: What it is, What is Controversial About it, and What We Might Do In Response To It, UCLA J. of Environmental Law and Policy, 9: 119-142.

    Botkin, D. B., R. A. Nisbet, S. Bicknell, C. Woodhouse, B. Bentley, and W. Ferren, 1991, Global Climate Change and California's Natural Ecosystems, pp. 123 - 149 in J. B. Knox (ed.), Global Climate Change and California: Potential Impacts and Responses, University of California Press, Berkeley.

    Botkin, D. B., and R. A. Nisbet, 1992, Forest response to climatic change: effects of parameter estimation and choice of weather patterns on the reliability of projections, Climatic Change 20: 87-111.

    Botkin, D. B., R. A. Nisbet and L. G. Simpson, 1992, Forests and Global Climate Change, Chapter 19, pp. 274- 290 in S. K. Majumdar, L. S. Kalkstein, B. M. Yarnal, E. W. Miller, and L. M. Rosenfeld (eds.) Global Climate Change: Implications, Challenges and Mitigation Measures, Pennsylvania Academy of Sciences, Philadelphia.

    Botkin, D. B. and R. A. Nisbet, 1992, Projecting the effects of climate change on biological diversity in forests, pp. 277 - 293 in R. Peters and T. Lovejoy, (Eds.) Consequences of the Greenhouse Effect for Biological Diversity, Yale University Press, New Haven.

    Guggenheim, D. and D. B. Botkin, 1996, CO2 Offset Opportunities in Siberian Forests, Report to the Electirc Power Research Institute, Center for the Study of the Environment, Santa Barbara, CA, EPRI report # TR

    Botkin, D. B., Henrik Saxe, Miguel B. Araújo, Richard Betts, Richard H.W. Bradshaw, Tomas Cedhagen, Peter Chesson, Terry P. Dawson, Julie Etterson, Daniel P. Faith, Simon Ferrier, Antoine Guisan, Anja Skjoldborg Hansen, David W. Hilbert, Craig Loehle, Chris Margules, Mark New, Matthew J. Sobel, and David R.B. Stockwell. 2007 "Forecasting Effects of Global Warming on Biodiversity." BioScience 57(3): 227-236.

    Ngugi, Michael R. and Daniel B. Botkin, 2011, “Validation of a multispecies forest dynamics model using 50-year growth from Eucalyptus forests in eastern Australia,” Ecological Modelling. 222: 3261– 3270.

    Ngugi, M.R., Daniel B. Botkin, David Doley, Mark Cant, and Jack Kelley.2013 “Restoration and Management of Callitris Forest Ecosystems in Eastern Australia: Simulation of Attributes of Growth Dynamics, Growth Increment and Biomass Accumulation.” Ecological Modelling 263 (2013) 152– 161.

    Ngugi, M.R., D. Doley, and D.B. Botkin, 2013. “Application of a forest dynamics simulator to inform sustainable biodiversity conservation and grazing management in Australia”.20th International Congress on Modelling and Simulation(MODSIM2013). 2013: Adelaide (December 1, 2013).

    Botkin, D. B., 2013. “What Forestry Needs in the Anthropogene,” The Forestry Source. September 2013 • Vol. 18, No. 9. p. 11. http://www.nxtbook.com/nxtbooks/saf/forestrysource_201309/index.php#

    Botkin, D. B., 2014 “Adapting Forest Science, Practice, and Policy to Shifting Ground: From Steady-State Assumptions to Dynamic Change.“ Sample, V. Alaric and R. Patrick Bixler (eds.). Forest Conservation and Management in the Anthropocene. General Technical Report. Fort Collins, CO: US Department of Agriculture, Forest Service. Rocky Mountain Research Station. (Reproduced at website http://www.forestbusinessnetwork.com)

    Botkin, D.B., M.R. Ngugi, and D. Doley. 2014. “Estimates and Forecasts of Forest Biomass and Carbon Sequestration in North America and Australia: A Forty-Five Year Quest.” Drewno 2014, Vol. 57, No. 192 DOI: 10.12841

    Ngugi, Michael R., David Doley, Daniel B. Botkin, Mark Cant, Victor J. Neldner & Jack Kelley. 2014. Long-term estimates of live above-ground tree carbon stocks and net change in managed uneven-aged mixed species forests of sub-tropical Queensland, Australia Australian Forestry DOI:10.1080/00049158.2014.979979 Published online: 26 Nov 2014.

    Ngugi, Michael R., David Doley, Daniel B. Botkin, Mark Cant. 2015. "Growth rates of Eucalyptus and other Australian native tree species derived from seven decades of growth monitoring." Journal of Forestry Research (in press)
    Shoemaker, W. B., Anderson, F., Barr, J. G., Graham, S. L., and Botkin, D. B.: Carbon exchange between the atmosphere and subtropical forested cypress and pine wetlands, Biogeosciences, 12, 2285-2300, doi:10.5194/bg-12-2285-2015, 2015.

  • Felix Ladstätter added an answer in SPSS:
    Can anybody help me with cluster analysing the antibiotic profiles in SPSS?

    Here is the link of an article, with the same.

    Felix Ladstätter · Instituto de Empresa SL

    Dear Jyothy

    You could try the Hierarchical Cluster Analysis of SPSS which gives you a cluster dendrogram like the one in the article you mentioned.

    I hope this helps you to start your analysis.

    Best regards,


  • Abdalla Tallafha added an answer in Topological Spaces:
    Could we find compactification of discrete topological space having infinite elements?

    one point compactification,stone Cech compactification...

    Abdalla Tallafha · University of Jordan

    Dear Mallamma, What you write "collection of singleton sets is an open cover for infinite set X which has no subcover." Mean the discrete topology on infinite set not compact, but you conclude that  we "cannot find compactification" this is not correct. As I mentioned before you can find one point compactification of any topological space.

  • Xinling Pan asked a question in Plasmid Extraction:
    What parameter should i take when i disperse mycobacterium smegmatis with ultrasonic?

    When i extract plasmid from mycobacterium smegmatis with plasmid extract kit, i add lysozyme into Buffer I with a final concentration of 10mg/ml. But after i respend bacterium with Buffer I, most bacterium appear as clump. Could i use ultrasonic to reduce clump size? What parameter should i take?

  • Harikrishnan Jayamohan added an answer in Microfluidics:
    Anyone familiar with variation in Microfluidic mixing?

    Suppose I want to mix two fluids in a microfluidic device, both fluids having the same inflow rate. After the two fluids have thoroughly mixed and reached the equillibrium concentration, I decrease the flowrate for both fluids, at the same time, to a value much lower than the previous flowrate at which equilibrium was reached. My qs is, whether the equilibrium position will be disturbed, and mixing will vary after I change the flowrate to the lower value??

    Harikrishnan Jayamohan · University of Utah

    For first part of your question, Comsol simulation can give you an answer. But it depends on how you "switch" from high to low flow rate. There is something called ramp & step function, which defines the rate of change of your flow rate (when you go from high to low). A sharp ramp might not give you a reasonable answer since in real world situations when you ramp down flow rate there will always be a "capacitance" involved.

    Pe depends on your characteristic length (not length of channel). Usually this depends on depth/diameter of channel (average length two layers/laminae of flow have to travel to mix). So low channel length does not correspond to low Pe. So for two channels with same cross-sectional area, the Pe will be same. I could not understand last line of your question.

  • Amir Borumand asked a question in LEDs:
    Any ideas on how to couple multiple LEDs into one fiber without mixing?

    Hi All,

    I need to couple multiple LEDs (with different wavelengths) into one fiber, while I don't want any mixing. I have to be able to switch between channels/wavelengths.

    There are some commercial devices out there but very expensive. I'm looking for a solution doable in a lab with lowest possible cost.

    Any ideas or insights are appreciated.

  • Michael Sulyok added an answer in QTRAP:
    How can I remove contamination in 5500 Qtrap?

    I have very low sensitivity and see charging, but the normal source cleaning (curtain plate, oriface plate and Qjet) hasn't solved the problem.  Is there something I am missing?

    Michael Sulyok · University of Natural Resources and Life Science Vienna

    Dear Naomi,

    I would  check the ESI capillary (might be blocked - try cleaning in an ultrasonic bath) and whether all small O-Rings in the source are still there (it happened once that one of the small amber coloured O-Rings came off, which caused intense signal drop in the negative mode).

    Another issue our service technician usually checks are polarization effects. Try a Q1 scan in pos mode, quickly change to neg mode and see whether there is an initial increase and then a drop. If this is the case, you will pürobably need the service technician.

  • Nika Kalynovska asked a question in Doublecortin:
    Does triple-labeling with DAPI, BrdU, and DCX work?

    Does anyone know if it works to triple-label mouse brain tissue with DAPI, BrdU, and doublecortin (DCX)? I'm using sections of the hippocampus and the subventricular zone to examine cells proliferation and neurogenesis.

  • Christian Boissinotte added an answer in Analytical Geometry:
    Has anyone ever rigourously proven the distance formula before?

    The only proofs I ever saw relied on intuition. The proof by similar triangles did something sort of like assume without proof that distance satisfies the following conditions:

    • The distance of every nonnegative real number r is r.
    • The distance of any complex number is a nonnegative real number.
    • The distance of any complex number is equal to the distance of its complex conjugate.
    • For any 2 complex numbers, the distance of their product is equal to the product of their distances.

    The proof by area assumes without proof that a rotation never changes the area of an object where a rotation is defined to be a complex multiplication by a complex number with a distance of 1. Maybe the facts that those 2 proofs assumed have been previously proven.

    Except for the page I wrote myself at https://proofwiki.org/wiki/User:Blackbombchu/Sandbox/Complex_magnitude_is_distributive_over_multiplication, I never saw any pages that define the distance of (x, y) to be sqrt(x^2 + y^2) without justification then prove the fourth condition from it.

    I never saw any full proof in pages other people wrote: only in ones I wrote myself such as http://speedydeletion.wikia.com/wiki/Distance_and_rotation.

    Perhaps just like some mathematicians don't feel the need to understand a mathematical proof of a statement when they have a computer-assisted proof, some mathematicians don't feel the need for a proof that there exists a distance function satisfying those 4 conditions when they instead have a physical proof, which is that they never observed a rigid object make an operation other than a rotation.

    Christian Boissinotte · Université du Québec à Montréal

    Got your paper on confidence intervals and started to read. Very neat !

  • Glenn Finger asked a question in iPad:
    What are your favourite apps for early childhood?

    While there's debate about early childhood and use of digital technologies, there's growing interest in identifying apps which are appropriate, including apps which can be repurposed for specific learning experiences.

    For example, there's sites which provide the '15 Must Have iPad apps for Preschool Teachers' - see http://www.earlychildhoodeducationzone.com/best-apps-for-teachers/. What are apps which you would recommend?

  • Abdur Rahman Asari added an answer in Mathematics Education:
    Teaching Math through exercise
    Math helps us exercise smartly.

    Abdur Rahman Asari · State University of Malang

    Realistics Mathematics Education, Contextual Teaching and Learning, Problem Based Learning are among many of models of teaching that we can use to teach our students to learn mathematics. At the same time, through these models we can use daily activities, including exercises, to help students better understand mathematics. I strongly agree that maths may help us to exercise smartly. Creativity, in the teacher side, is very important in designing and implementing exercises through mathematics teaching. 

  • Deborah Wearne added an answer in Auditory Hallucinations:
    Can someone suggest a clinician rating scale for dissociation and pseudo hallucinations?

    We are inexperienced researchers and need help. We are interested in the phenomenology of pseudo hallucinations. We believe that clinicians can differentiate the experience of auditory hallucinations and pseudo hallucinations, possibly through features of dissociation. It is just hard to operationalise. Any advise would be great

    Deborah Wearne · maia house

    Sorry I need to practise my typing! We did a simple project using the PSYRAT comparing hallucinations in PTSD with dissociative features DSM 5 and schizophrenics. We found similar features in both experiences but a very significant increase in delusions in schizophrenics. We want to continue our interest in an increased but still keep the project simple. We are thinking of looking at complex PTSD and borderlines and using the PSYRAT again with an instrument that assesses dissociation. I know it is a murky area

  • Armiya Sultan added an answer in Frequency Ranges:
    How can I find no. of formants between two frequency range?

    I followed the method given in the paper " Formant Location from LPC Analysis data" by Roy C. Snell and Faustro Milinazzo. BUt i could not understand the way they are bisecting the interval .can any one  help ?

    Armiya Sultan · Pt. Ravishankar Shukla University

    Attached files may b helpful

  • Maryam Barzegar asked a question in Nano-Silica:
    Do you know articles about effects of nano silica particles on plants?

    I need some articles about effects of silica nano particles on plants, especially rice and wheat.