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  • Can anyone help with catalytic cracking of polyethylene using aluminum dross as a catalyst?


    I am using al dross as a catalyst  cracking of polyethylene. How can I activate it because I run TGA the peak was not shifted. can any one suggest way to make it active 

    thanks alot 

    Abdulkreem Ghassan Alsultan · Putra University, Malaysia

    thank you Hamida Mohammed Bakr Darwish

    my problem with catalyst activation can you advice me a way to activate it 

  • Why exactly diamagnetic materials have no initial magnetic moment in absence of external magnetic field?

    What is going on the electron level? or molecular level? or atomic level? why all the materials have this property? is a ferro, para magnetic materials are also have some partly diamagnetic properties? what changes happens to the structure of a diamagnetic material when subjected to a magnetic field? what the magnetic moment actually means in a material?

    Manjunath Nayak · Goa University

    Well, That requires quantum mechanical explanation, I would suggest you to read book on Introduction to Magnetism and Magnetic Materials By Jiles, David

  • How can I increase my 260/230 ratio- Qiagen RNeasy Mini Kit?

    Hi everyone, I'm looking to extract high quality RNA from frozen PBMCs (~400,000 - 1 million cells) in order to look at gene expression using qPCR. My RNA yield has been around 100ng/ul and the 260/280 ratio around 1.90. However the 260/230 ratio is very variable from 0.28-1.75 .. I believe this number needs to be >1.85 in order to perform reliable qPCR analysis. Has anyone had this experience and has any tips/protocols/recommendations? As well, I've heard that the RNA yield could be higher ~300ng/ul, do you have any recommendations for increasing the yield?


  • Nizar Matar added an answer in Replication Origin:
    How important is Biology-based knowledge in Art Education?

    If one asks 10 artists to copy the famous painting using the same material, the 10 copies will most probably differ in at least one scale of analysis or perception. Different copy artists evidently differ in how they perceive originals. They also differ in use of colors. Copy artists also differ in how a paint brush is held, reflected for instance in orientation, strength at the time brushes touch support, or the angle or distance of observation. If one painting requires >1000 brush touches, what is the probability that two artists replicating an original painting produce exactly same series of brush touches? Do differences between originals and replicates exist because of artistic liberty (e.g. differences were wanted), logistic constraints (e.g. availability of material), biological constraints (e.g. arm and hand design holding the brush, eye characteristics influencing perception), or environmental (e.g. light) conditions at the time of creation? Historical data will never be able to identify the exact origin of paint or the exact proportions of the different colors that were applied by the original artist. Scientists or history experts also do not have access to details of biology that influenced how original artists made artistic creations. Moreover, if an artist makes without so-called conscious acts a close match of another painting should the painting be called a replicate, a copy, or an original?

    Nizar Matar · An-Najah National University

    It is very difficult for 10 artists to copy a famous painting and then produce exactly identical pieces of art or one which is 100% paste of the original. Slight differences will be found by those who are experienced & these differences are not necessarily negative. Sometimes, they may look better! in the eyes of some appreciative persons. I really understand the biological constraints because I am interested in paintings & calligraphy myself. As one proceeds in age, the hands will "shake" a little bit & the vision will become less sharp. Even the focus of interest may change due to a change in the mood ,e.g. I gave up drawing funny pictures moving into more ornamental scientific ones.

  • Andrés Pavas added an answer in Harmonics:
    What are the existing methods for non-sinusoidal and non-linear current compensation?

    What are the existing methods for nonlinear, non-sinusoidal, and non-periodic load current compensation? what are the existing challenges? Is there any verified method for the compensation of a large harmonic generating load (such as arc furnace)? 

    It would be really appreciated if some papers or dissertations are provided.

    Andrés Pavas · National University of Colombia

    I would suggest to track the publictions of Volker Staudt (Germany), Alexander Emanuel (USA), Paolo Tenti (Italy), Mauricio Aredes (Brazil) and Leszek Czarnecki (USA). They are the most acknowledged researchers on Electric Power Theories and work in compensation issues (measurement, decomposition, analysis, compensation, etc.).


  • Can e-waste be recycled?

    Electronic waste or e-waste means discarded electrical or electronic devices. They are needed to be recycled in order to make the environment clean and better for us.

  • Morteza Amjadi asked a question in Graphene:
    How to measure the amount of produced graphene via exfoliation process?

    I am producing graphene solution by exfoliation process. I am wondering how we can measure the amount (weight or concentration) of produced graphene? 

  • Pankaj Roy added an answer in River Engineering:
    Can anyone suggest any open source user-friendly software?

    I need to draw some diagrams to show horizontal and vertical distribution of flow velocity. I will be grateful if some one suggests for it! Thank you!!

    Pankaj Roy · North Eastern Hill University

    What I need to develop/draw is something looking like this...if anybody can do a favour! 

  • Does the immune response contribute to the brain damage in Primary Amoebic Encephalitis more than the cytotoxicity induced by the Naegleria itself?
    Re: Naegleria Brain damage.
    Abdul Mannan Baig · Aga Khan University, Pakistan

    See the article below. Review on the subject

    Baig AM. Pathogenesis Amoebic Encephalitis: Are the Amoebas being credited to
    an 'Inside job' done by the Host Immune response? Acta Trop. 2015 Apr 27. pii:
    S0001-706X(15)00119-9. doi: 10.1016/j.actatropica.2015.04.022. [Epub ahead of
    print] Review. PubMed PMID: 25930186.

  • Paul Finn added an answer in Toluene:
    Is anyone familiar with waters 501 HPLC solvent compatibility?

    I have an old "Waters 501 HPLC Pump" - I wanted to know what solvents this system is compatible with? I don't want to use it for LC, I want to use it as a pump for some organic chemistry flow reactions. Any ideas or a good website/reference?

    I assume it can be used for normal phase, so organic solvents should be ok, but I really wanted to know about toluene.


    Paul Finn · Temple University

    Thanks all, The pump is working great. I have one last question.  I Have it set up to flow thru a photoreactor.  One thing that i'm noticing is i'm getting a lot of bubbles coming out of the pump.  No bubbles are being sucked in from the solvent reservoir, but air bubbles are coming out.  any thoughts?  

  • Mohammad Shirdel added an answer in Martensite:
    Which chemical attacks can reveal the morphology of the different phases present and the joints of martensitic grains in the alloy Fe-10Cr?

    Which chemical attacks can reveal the morphology of the different phases present and the joints of martensitic grains in the alloy Fe-10Cr?

    Mohammad Shirdel · University of Tehran


    You can use the following articles for acquiring an acceptable etching solution for martensite/austenite matrix:

    Nano/Ultrafine Grained Austenitic Stainless Steel through the Formation and Reversion of Deformation-Induced Martensite: Mechanisms, Microstructure, Mechanical Properties, and TRIP Effect

    Microstructural Evolution During Normal/Abnormal Grain Growth in Austenitic Stainless Steel

  • Renzo Bianchi added an answer in Self-Report:
    Do you have any suggestions for pre- and post-stimuli state anxiety measures?

    For my Master's thesis, I need to measure participants' state anxiety before the presented stimuli (synonyms of the same word) and immediately after. There will be very little time, less than 5 minutes between the measures.  Because of the short time frame, I would rather not use the same self-report measure both times. However, I need to be able to compare the two so they have to be comparable measures or different versions of the same measure. This is not my primary DV, but one that I believe will be a moderating factor. Does anyone have any suggestions? I could really use your help. Thank you.

  • I have aqueous , and i will be use it in the extraction of plant leaves by hot and cold method.please i need information about hot and cold methods?

    i have aqueous , and i will be use it in the extraction of plant leaves by hot and cold methods.please i need information about hot and cold methods?

    Raghed IBRAHIM Esmaeel · Universiti Teknologi Malaysia

     thank you so much 

  • Akira Kanda added an answer in Orthogonalization:
    Can rotation in Minkowski space-time be the product of two rotations about two lightlike planes?

    It is known that rotation in Minkowski space-time is product of two rotations about spacelike and timelike mutually orthogonal planes. Can we represent  rotation in Minkowski space-time as a product of two rotations about two lightlike planes?

    Akira Kanda · University of Toronto

    BTW, in geometry, we do not consider "motion". We consider "geometric transformation" however. They are entirely different things. It is regretful that in the community of mathematical physics, mathematics is abused in this way.

    Let me point out that among physicists, similar criticism on mathematical physics is mounting. For example, theoretical and mathematical physicist ignore the dimensional analysis which is the most important but simple theory of Physics. In Physics, the most fundamental dimension is [length] and [time]. They are undefinable dimension. Out of it we define new dimensions such as [speed]=[length]/[time] and [acceleration]=[speed]/[time].

    In relativity theory, [time] is defined by [speed] and [length] is defined by speed too.

    No mathematicians do this kind of nonsense. It is called shooting your own feet. May god bless time dilation and length contraction.

  • Renzo Bianchi added an answer in Visual Stimuli:
    Has anyone come across any research of association between colors and behaviors/moods?

    Any correlation between colors (visual stimuli) and behavior/mood (brain activity)?

  • Kiran Bhatreja asked a question:
    I want to have more inofrmation and content of this topic:Deisgning the perfect drillinfluid additive:can it be done?

    I want to have more inofrmation and content of this topic:Deisgning the perfect drillinfluid additive:can it be done?

  • Andrés Pavas added an answer in Power Quality:
    Can this method be used in voltage related problems?

    Whether this method is able to use in voltage related problems  because you had mention voltage sensorless algorithm and without sensing voltage how can we mitigate the voltage related problems in the network?

    Andrés Pavas · National University of Colombia

    Resorting to estimators to control a power quality compensation device (it doesn't matter whether voltage or current is the target) faces several difficulties related to uncertainties in: system parameters, load, system dynamic behaviour, actual compensator response, etc. All these uncertainties do not imply that estimators should not be employed, it means that uncertainty management techniques need to be used.

    For low frequency phenomena, e.g. unbalance, rms voltage fluctuations, load changes, etc., estimators can be quite accurate, even for some low frequency harmonics. But higher order or time varying harmonics, interharmonics, supraharmonics and random events (transients, voltage dips, etc.), the system existing devices behave different to ideal expected conditions, thus the model can be expected to be inaccurate. In addition, harmonic generating loads interact with each other in difficult to forecast ways, therefore measurements are always more reliable to control compensating devices.

    Hopefully this short comment might be helpful.

  • 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.

    Ravinder Jerath · Augusta Women's Center


    Subjectivity -- a perspectival locus of origin within a brain representation of our surrounding space -- is the hallmark of consciousness. 

    1. What brain mechanism in your model gives us our subjectivity?

    I believe it is entire brain and body that forms a space that our thalamus perceives  as external space. It has two components 1) visual 2) non visual .

    2. How does it do the job?

     The way it does the job is that just like striate cortex provides distance of the space to retina and LGN , the right parietal cortex  does to rest of body . Stroke and lesions  Right parietal cortex makes a person essentially blind on the left visual and non visual space. 

    This is a question that should be asked of all candidate models of consciousness.

    Is Chalmers' so-called "hard problem" in consciousness real?. Available from: https://www.researchgate.net/post/Is_Chalmers_so-called_hard_problem_in_consciousness_real [accessed May 3, 2015].

  • Luis Quirós asked a question in ESI-MS/MS:
    Does anyone know if there are fragmentation mechanisms for molecules in negative mode detected by ESI-MS/MS?

    with mechanismo i mean, like a reaction mechanism that involves arrows and charges, they are common in positive mode but i need them in negative mode.


  • Yosef Jabareen added an answer in Urban Environment:
    Can anyone suggest VRP data sets defined in urban environments?

    Can anyone suggest me VRP data sets defined in urban environments (big cities), with locations given in terms of latitude and longitude?

    Yosef Jabareen · Technion - Israel Institute of Technology

    I will try the Big Data

  • Robotics: Which Journal for Publication of a non-technical paper ?


    I am preparing a paper for a company. The paper describes the company's commercially available robots that are used by researchers.

    The paper describes the robots, their specifications and their features in order to allow researchers to cite this paper as a reference in their own papers.

    The paper is not very technical. The control architecture, design and functionalities are presented but not in deep details with equations.

    I thought submitting to IEEE Robotics & Automation Magazine but I wasn't sure if it would fit with their scope.

    What do you think for IEEE Robotics & Automation Magazine ?

    Any other suggestions ?

    Thank you very much !

  • Carbon conversion of biomass gasification?

    I am working on gasification of biomass...currently facing problems in calculating carbon conversion for each experiment from out put gas..

    For explanation: CHNS analysis of biomass is C = 50%, H2 = 6 %, O = 22, N = 14 %, S is 6 %.

    Following are the results from one of my experiment in mol %.

    H = 30 mol%

    CO = 22 mol %

    CO2 = 40 mol %

    CH4 = 8 mol % 

    Now, how i can calculate carbon conversion please help me, Thankyou

    Vanessa Meloni Massara · University of São Paulo

    Dear Abdul,

    Please see these material. I believe will help:




    and this book:

    Carbon Conversion During Bubbling Fluidized Bed Gasification of Biomass
     by Kevin Jay Timmer



  • Yosef Jabareen added an answer in SAN:
    Can someone provide a reference research paper for zoning in SAN?

    Zoning implementation in SAN

    Yosef Jabareen · Technion - Israel Institute of Technology

    The best resource is at the website of APA

    The American planners association

  • Yue chun Li asked a question in Arterial Stiffness:
    What are the reasons for the non-linear progression between arterial stiffness and thickness?

    Hi, everyone, the paper below reported that the IMT of common carotid artery had a poor correlation with pressure-strain elastic modulus at lower thickness value (CIMT<0.88mm, r=0.24, p=0.08), but this association became stronger with increasing thickness (CIMT>0.88mm, r=0.62, p<0.001) .

    I want to know the physiological mechanism behind this phenomenon. Could you please recommend some papers about this field to me ?

    Thank you very much!

  • Ahmad Bazzi added an answer in DOA:
    How can I resolve the coherent DOA estimation problem?

    How to resolve the coherent DOA estimation problem? i need brief answer asap.

    Ahmad Bazzi · Institut Mines-Télécom

    But Bartlett could estimate only one DoA, no ? 

  • Do I report descriptive statistics and correlations of variables before or after their transformation (log and sqrt)?

    I transformed some of my variables (logarithmic and squareroot) to reduce skewness and improve normality. My question: Which variables should I use in the 'Results' section to report Descriptives and Correlations? The original variables or the variables after transformation?

    Thanks a lot in advance!

  • Andrés Pavas added an answer in Harmonic Analysis:
    Starting from what length (and frequency) should we consider distributed line model for power distribution lines?

    As a rule of thumb for transmission lines, we know that short lines (shorter than 80 km) are modeled as series impedance, medium lines (80-250 km) are modeled as PI section, and long lines (>250km) are modeled using distributed line models.

    Now, when we perform harmonic (higher frequency) analysis on distribution network with underground cables (which have large parasitic shunt capacitance), the wavelength dramatically decreases. 

    Is there any study to estimate in what frequency or line length (or in general in what multiplication of the wavelength) we consider distributed model for distribution lines for harmonic analysis? 

    Andrés Pavas · National University of Colombia

    Dear Amin,

    both models, lumped and distributed parameters, are accurate and reliable depending on the wavelengths, as the other comments have already noted. You can get accurate results using lumped parameter models if the wavelength is at least 10 times the line length. The same thumb rule can be applied for choosing the distributed parameters model, if the signals have wavelengths below one tenth of the line length, you should employ a distributed model.

  • How might I use the B&K Pulse Labshop for modal analysis ?
    I want to do my experiment by using Bruel & Kjaer Pulse Labshop for calculating natural frequencies of beam. Experiment set up is there, but there is no tutorial or user manual. Anyone have a user manual or tutorial for this experiment? Please inform me .
    Abdelghani Mansouri · The Robert Gordon University

    I am also working on the same experiment but I am using an impact hammer. Me too am suffering from the same problem as Mr Ranjan Kumar. If any one can help, I will be really grateful.