Materials Engineering

Materials Engineering

  • Antoni Sanchez-Ferrer added an answer:
    What would be the zeta potential of polyacrylamide gel synthesized in water at different pH?

    I am looking for any article or supportive document which suggest the surface charge behaviour of polyacrylamide in water at different pH.

    Antoni Sanchez-Ferrer · ETH Zurich

    Welcome!

  • Mahmoud Abdelaal added an answer:
    How can I reduce contact angle of polystyrene nanofiber film?

    The contact angle is approx 120, I would like to reduce it. I tried cold plasma, but it is still the same. Look forward to any suggestions....

    Mahmoud Abdelaal · Northwest A & F University

    fristly olystyrene nanofiber film is wrong because no nanofiber film , nanofiber is membrane and i want to know what is the fiber diameter and and which solvent you have used 

  • Dan Rhonehouse added an answer:
    Can anyone throw some light about the oxidation states of iron in phosphate glass?

    Can anyone throw some light about the oxidation states of iron in phosphate glass? I mean in which oxidation states iron presents in phosphate glass?

    Dan Rhonehouse · NP Photonics, Inc.

    Fe oxidation state in phosphate glasses is highly dependent on concentration and  melt conditions. In ppm levels under inert or reducing atmosphere there will be substantial amounts of Fe2+ and absorption in the visible and near IR region at common laser wavelengths. Under oxidizing conditions this can be nearly completely driven to Fe3+ and absorption reduced dramatically.

    P. Ehrmann, J. H. Campbell, T. I. Suratwala, J. S. Hayden, D. Krashkevich, and
    K. Takeuchi, “Optical Loss and Nd3_ Nonradiative Relaxation by Cu, Fe and Several
    1068 Journal of the American Ceramic Society—Ehrmann and Campbell Vol. 85, No. 5
    Rare Earth Ion Impurities in Phosphate Laser Glasses,” J. Non-Cryst. Solids,
    263–264, 251–62 (2000).

    K. ZirkK. Zirkelbach and R. Bru¨ckner, “Spectroscopic Investigation of Barium Aluminophosphate Glasses Containing Vanadium, Iron and Manganese Oxides,”
    Glastech. Ber. Glass Sci. Technol., 60, 312–17 (1987).

  • Zouheir Hamdoun added an answer:
    What would be more beneficial while fabricating glass/kevlar woven hybrid laminate?

    While preparing glass/kevlar hybrid laminate, would better structural properties be obtained by placing kevlar on the top and bottom or is kevlar better in the midplane?

    Zouheir Hamdoun · Higher Institute for Applied Science and Technology

    Would you give more details about nature (almost bendingand, compression, impact, ...)  level of loading?

  • Marius Murariu added an answer:
    Can anyone assist me in designing and engineering a high pressure reactor system for the continuous production of nylon 6-12 polymers?

    I am looking for a manufacturers and/or engineering and design  of high pressure reactors for the continuous production of nylon 6-12 material. Low pressure reactors are common but there are very few producers of nylon 6-12 so there does not seem to be many sources of this equipment. It is more likely that it will need to be custom engineered.

    Marius Murariu · Materia Nova R&D Center & University of Mons

    Dear Mr. Wells,

     Because I was involved in the production of some types of polyamide, for instance my first advice is to contact some companies that have recognized experience in the production of polymerization plants (i.e. for polyamides). Of course, you need to give more details, a continue polymerization process can imply some high financial costs, but you did not specify some about the capacity of this laboratory plant (this is my assumption).

    I will give some limited examples of companies of engineering equipment /plant manufacture that can be concerned by you for a preliminary information:

    Uhde Inventa-Fischer (http://www.uhde-inventa-fischer.com/company/our-company)

    Sulzer (http://www.sulzer.com/en/Products-and-Services/Process-Technology/Polymer-Production-Technology/Other-Polymer-Applications/Polymer-Production)

    Aquafil Engineering (http://www.aquafileng.com/index.php/Polymer_Plants.html)

    etc. I will attach also some documentation, maybe helpfully in your approach.

    Finally, I will you wish you to find  ASAP the most convenient offer, so good luck and best regards,

    Marius

  • M.Nour Nashed added an answer:
    How to calculate cyclization index from FTIR data of Oxidised Polyacrylonitirle?
    Any suggestions for calculation of Cyclization index from FTIR data of oxidised PAN fibre.
    M.Nour Nashed · Aleppo University

    FTIR alone can't determine the cyclization index .

    you will be in need for more tests to detrmeine the oxidation index such as : XRD, DSC, GC

    there is an equation can help you to calculate cyclization Index according to FTIR.

    A=I/ ( I +Io )

    Io : the measured intensity of the conjugated band at 1600 cm-1,  associating with the developing structure, 

    Iv :  the nitrile band at 2240 cm-1 belonging to the unmodified PAN molecule

    I  hope it was beneficial for you

    for further details you can read the following article:

    Y.Zhu, M.A.Wilding and  S.K. Mukhopadhyay ," estimation using infrared spectroscopy , of the cyclization of polyacrylonitrile during the stabilization stage of carbon fiber production" journal of material science 31 (1996) P:3831-3837

  • Tapan Barman added an answer:
    How can I calculate the percentage of composite materials?

    The EDX analysis of any composite samples gives only a rough estimation of the elements present in the composite and the XPS gives information about surface bounding species. So, what is the way to calculate the percentage of different materials present in a particular composite?

    Tapan Barman · Institute of Advanced Study in Science and Technology

    Thanks a lots for your's valuable reply....

  • D. Martinez Krahmer added an answer:
    How many force exist for lathe tool in lathe machine?

    How many force exist for lathe tool when working on lathe machine and using lathe tool dynamometer for measuring?

    D. Martinez Krahmer · Instituto Nacional de Tecnologia Industrial

    Excuse me. In turning operations there are only 3 components: cutting force, axial force and radial force. The "others" forces, like friction and shears they are part of the same.

    You can studu the merchant circle for more explanation about this.

    A most famous manufacturers of piezoelectric dynamometers is Kistler. Your model for turning is the 9363 type (three component dynamometer)

  • Jeoung Han Kim added an answer:
    Is there a way to increase the hardness of A286 (or SUH660) steel above 34HRC?

    We are trying to manufacture fasteners made of A286 steel. The fasteners were forged and solid solution treated at 900oC for 2.5hours followed by 680, 720, or 740oC aging for 16hours, which is well-known heat-treatment process for gamma' precipitation of A286. After then, hardness in the range of 30-32HRC was obtained.

    This result is pretty much unsatisfactory to us because we need to make A286 fasteners with 34HRC or above. I heard that maximum hardness of A286 would be around 35-36HRC but our heat-treatment couldn't lead to the value.

    Can anybody suggest any heat-treatment process to improve hardness of A286 steel? Unfortunately, we cannot conduct cold rolling more after solid solution treatment due to client's request. For your information, grain size of our materials is around 12-13 micro meter.

    Any assistance would be greatly appreciated.
     
    Thank you,

    JH Kim

    Jeoung Han Kim · Hanbat National University

    Dear Pohlman, your answer sheds light on this problem. I deeply appreciate.

    Really, hardness above 34 HRC looks very difficult to achieve. I already asked my client whether cold working between solution and aging treatment could be introduced. But, they said no for some unaccountable reasons.

    I analyzed microstructure and found that raw material contains relatively large amount of TiC, which is unfavorable for gamma' particles precipitation. I think these TiC particles may cause the decrease of hardness value.

    I’ll try the aging treatment at lower temperature for longer time over 50 hours. I hope this heat-treatment can increase hardness of A286 little bit more.

    Many thanks to all of you

  • Mohammed M. Obeid added an answer:
    Suggestion of ceramic materials or topics

    Dear scientist,

    I would like to know the most recent studied ceramic materials and their applications. I am looking for your suggestions and your thoughts about ceramics topis,applications and techniques. thanks

    Mohammed M. Obeid · University of Babylon

    thank you dear mr. Mehdi for your cooperation and sharing your thoughts.... I wish you good luck in your future endeavors..

    Best regards,

  • Khalid Abdalla added an answer:
    Can I use rare earth oxides as a coating for pipes to prevent corrosion?

    I like to know if I can use rare earth oxides as a coating for pipes to prevent corrosion  

    Khalid Abdalla · University of Science Malaysia

    It is possible to get conversion coating based on REO. However this kind of coating dose not exhibit high corrosion resistance compared to other conversion coatings like zinc phosphate coating or Zn-Ca phosphate coating. These coatings could provide superior corrosion resistance if combined with organic coatings like Polyethylene (PE) or polypropylene (PP) or that coatings based on epoxy resin.

  • Nicolò Maccaferri added an answer:
    What is broken time reversal symmetry in ferro magnetism?
    I know broken time reversal symmetry is responsible for ferromagnetism. But i want to know what really a time reversal in solid systems.
    Nicolò Maccaferri · CIC nanoGUNE Consolider

    Dear Tapan, the reflected light from a magnetized sample, depending on the orientation of the magnetic with respect to the scattering plane and the sample surface, is no more linear but elliptical and rotated by an angle with respect to the direction of oscillation of the impinging electric field polarization...you can define two quantities, the Kerr ellipticity and the Kerr rotation which are the imaginary and real part, respectively, of a quantity called complex Kerr angle. An interesting introduction related to this topic can be found in the Freiser's article on IEEE Transaction on Magnetics 

    A survey of magnetooptic effects

    http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=1066210&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D1066210

  • Gerhard Leichtfried added an answer:
    What are the methods for ferro tungsten production?
    Carbothermic, aluminothermic, silicothermic.
    Gerhard Leichtfried · Plansee

    Hi Ahmed,

    the raw materials are rich ors, concentrates or scrap. Carbothermic and carbothermic-silicothermic reduction is preferred for cost reasons. Metallothermic reducion is of less importance.

    Best regards

    Gerhard

  • Kaustav Sarkar added an answer:
    Is there a simple method to prepare artificial pore solution corresponding to the cement based systems?

    Please advice on any reliable and preferably a simple technique for the synthesis of solution representing the pore solution of ordinary cement system.

    Kaustav Sarkar · Indian Institute of Technology Delhi

    Thank you Mr. Lura for your valuable advice. Yes I will like to have the data and it will be of immense help. I am messaging you mu email id. Thank you again for sharing your ideas.

  • Abdulrahman Althuwayb added an answer:
    What methods can I use to check the shape of crystals?

    Dear All

    I have analyzed the quasicrystal i have prepared by xrd, but i'm not sure if the crystallization is correct. I know that we can check it via TEM or another method. May I ask about the other method which we can check the shape of the crystal?

    BR

    Abdulrahman Althuwayb · King Fahd University of Petroleum and Minerals

    As Mr. Zwi said, the use of tomograph device might be useful.

  • Maziar Dehghani added an answer:
    Does anyone have experience with sound insulation of underfloor heating systems?

    Hi, I am looking for papers and data on impact sound insulation and dynamic stiffness of materials commonly used in these systems, in particular polystyrene.

    Maziar Dehghani · SGP co

    Search for xpe foam

    it may opens a new window to you

  • Vasiliy Triandafilidi added an answer:
    Structure relaxation and energy minimization - can anyone help?‏

    I am trying to do structure relaxation and energy minimization by using Reax, eam and meam poetntials for nanorods (you can see input and data files in attachment).

    Before I did both relaxation and minimization for very similar kind structures but for this I am not getting any results, its still running even after 30 hours.

    What could be wrong?

    I would really apperciate your comments/suggestions.

    Thanks!

    Vasiliy Triandafilidi · University of British Columbia - Vancouver

    Sometimes minimization can take very long time.

    but you can use  fix 1 nve/limit 0.01

    which won't let the system to explode for an equilibration

  • Enrico Piccinini added an answer:
    How can i simulate PCM(Phase change memory) Mushroom cell structure in Silvaco TCAD?

    I made structure using DEVEDIT and selected PCM( or GST) as phase change material. But when i run the simulation in ATLAS, i got the error " no default thermal conductivity model for PCM(or GST)".

    Enrico Piccinini · University of Bologna

    You can find it on Eric Pop's website poplab.stanford.edu

  • Does anyone know how Ni contributes on the stainless steel passivity?

    I`m working on the evaluation of localized corrosion of duplex stainless steel in H2SO4 and HCl at different concentrations and I'm confused about the effect of Ni on the corrosion resistance of these alloys?

    Marco ARTURO Garcia-renteria · Instituto de Investigacion en Metalurgia y Materiales

    Thanks

  • Kaustav Sarkar added an answer:
    Is there any model for the estimation of open porosity of concrete?

    Open porosity or water permeable porosity is known to be an important parameter in the study of liquid water ingress in concrete. Has there been any significant research in this area with any substantial general insights? Please advice on the same.

    Kaustav Sarkar · Indian Institute of Technology Delhi

    Thank you madam Jie Liu

  • Brian Prasad added an answer:
    How to apply the principles of lean startup to materials science and engineering entrepreneurship?
    Lean startup from Eric Ries' book says that the build-measure-learn loop is a way to put your product out there upfront and have it tested against actionable metrics and with real users (early adopters, at this stage). It tells you to have a minimum viable product designed with acceptable flaws but that serves to measure a certain hypotesis of value or growth. I tried to google around some startups in the materials engineering and science field, and Ries even cites one in his book. What I did not found (or thought of) is how to transpose his principles to startups dealing with materials. I myself am starting one and I find it tricky to tweak my material to have certain properties as an MVP. Does anyone have expertise in this field? How do you have your product tested? Do you ship free samples to potential customers? Do you put up a fake e-commerce just to track customer clicks and advertise the website?
    Brian Prasad · California Institute of Technology

    Here is one idea that has worked for me.

    I believe you need to create a systematic well-thought out plan based on value-based engineering and world-class measurements. You need to determine what are the characteristics that you are looking for in that product that are differentiators for the future products or to its future customers.  Then, you need to choose new ways of satisfying those characteristics (say new solutions or new strategies) via a set of possible means (such as tools and techniques), including techniques such as material substitutions.

    Then, you need to perform a value-based measurement or performance evaluations -- finally create a matrix of characteristics versus strategies.

    Rank them and evaluate what works the best.

    Based of such findings, you need to marrow down the choices to a couple that are more valuable to you and the customers.

     I followed this methodology in many novel applications. The following paper shown here describes an such a methodology presented in a generic fashion.

    Let me know if you have any questions.

    Your inputs will help others to take such bold steps.

    Thanks

    Brian

  • Nihad Ben Salah added an answer:
    Why Young's modulus is not same for gold chain and gold nanowire, even though YM is structure insensitive?

    As Young’s modulus (YM) is a structure insensitive property, size of the sample should not matter. But it does. The YM for a gold chain is not the same as YM for a gold nano-wire. Why? Thanks to Prof.S.Ranganathan sir (IISc) for posting this question in TRAERF site. I had this doubt.

    Young modulus is sensitive to grain size at the nanoscale level. It decreases when the nano-grain size decreases until the amorphous state that is the state where YM is the lowest. See: C.A. Schuh, T.C. Hufnagel, and U. Ramamurty: Acta Mater.,
    2007, vol. 55, pp. 4067–4109

  • Carlos Araújo Queiroz added an answer:
    Chemical etchant or thermal etching condition for graphite?

    I would like to know the thermal etching conditions and if there is any chemical etchant for graphite.

    Carlos Araújo Queiroz · New University of Lisbon

    Graphite can be etched (oxidized) with concentrated nitric or sulphuric acids (preferably hot), with concentrated sulphuric acid and potassium dichromate (slow attack at room temperature), or with a mixture of concentrated sulphuric and nitric acids with added potassium chlorate (relatively strong etchant): 40 ml H2SO4 + 20 ml HNO3 (~60% w/w) + 10─20 g KClO3. Alkaline etching is also possible with hot concentrated aqueous solution of KOH or NaOH (~50% w/w). 

  • Arvind Singh added an answer:
    I got surface area less than 100 m2/g. But from literature we saw that surface area was more than 1000m2/g. Is it possible?

    BET Surface Area of Grephene.

    Arvind Singh · Indian Institute of Technology (Banaras Hindu University) Varanasi

    From Raman, FTIR & XRD, I have confirmation that the product is Graphene. Thank you sir  for your suggestion  &  discussion.  Now I am trying to reduce it.

  • Gourbeyre Yannick added an answer:
    How can I perform the DL-EPR test ?

    I want come to know about the DLEPR test to check the sensitization of stainless steel.

    Gourbeyre Yannick · Veolia Environment

    This electrochemical test is performed with a potentiostat in a three electrodes configuration.
    The electrolytic solution is often a mixture of H2SO4 with KSCN whose ratio can change with the stainless steel you test and someone ads also HCl (exemple:https://online.unileoben.ac.at/mu_online/voe_main2.getVollText?pDocumentNr=26062&pCurrPk=21619) .

    The tested specimen has to be polished (some say at least a 100 grit finish).

    This method involves polarizing the specimen anodically from the corrosion potential to some preselected passive potential using a chosen scan rate (forward scan). Then, using the same scan rate, a reverse potential scan is performed to the corrosion potential (reverse scan).


    The current peak formed during the forward scan is called “activation peak” whereas the current peak formed during the reverse scan is called “reactivation peak”.
    During the forward sweep, the whole surface is active and contribute to the peak current ; during the reverse sweep, only the sensitized grain boundaries contribute to the passive-active transition


    The degree of sensitization is given by the ratio of the two peaks (some use maximum of currents density other use the charge) : higher is the peak , heavier sensitized is the tested specimen.

    Hoping it could help.

    Ther are many papers on this topic in the litterature.

  • Could you explain this paragraph related to graphene?

    Graphene is composed of sp2-bonded carbon atoms arranged in a two-dimensional honeycomb lattice.
    The lattice can be seen as consisting of two interpenetrated triangular sub-lattices, for which the atoms of one sub-lattice are at the center of the triangles defined by the other with a carbon-to-carbon interatomic length, a(C–C), of 1.42A°. The unit
    cell comprises two carbon atoms and is invariant under a rotation of 120 degree around any atom. Each atom has one s orbital and two in-plane p orbitals contributing to the mechanical stability of the carbon sheet. How they contribute to the mechanical properties?

    Mohammed Elaghdef Malainine · GREENTECH Industry

    TO: Pushpendra Singh

    First: to better understand Kien-Cuong Pham explanation, I think you need to read and understand more about Crystal structure. (wikipedia has this quick but great article.)

    Second: Graphene extraordinary physical properties are explained partly by the remaining free electron for each carbon that could be then engaged in the transport of heat and electricity, very much like other carbon based material (allotropes) like  graphite, charcoal, carbon nanotubes and fullerenes.

    But most scientists think those extraordinary properties are partly explained by the remarkable disposition (packing) of carbon atoms in the same plan, hense the study on the cristallographics (lattice unit, symmetry...)

    Regards,

    Malainine

  • Aravinda Jayawardhana added an answer:
    Can we expect any chemical reaction between coir fiber and epoxy resin?

    We are going to use coir fiber as a reinforcement to produce a plastic. So we need to know, can we expect any chemical reaction between coir fiber and epoxy resin?

    Aravinda Jayawardhana · University of Moratuwa

    Thank you for all your answers..You all have confirmed and suggested surface modification..I'm going to proceeding with surface modification. I'll let you all know how is the progress.

  • Zalita Zainuddin added an answer:
    How do I determine the dielectric constant of a material by knowing specific capacitance?

    I am working on electrochemical properties of materials, I have specific capacitance of a material. Can I determine dielectric constant of the material? Please any one help me about this.

    Zalita Zainuddin · National University of Malaysia

    I think if you have the frequency (f), AC capacitance (C') and conductance (G) data, you can convert them to real and imaginary impedance data, and plot a -Z" vs Z' graph. To determine DC capacitance, the data & impedance plot can be used for modelling using an equivalent circuit based on combination of resistor/s, R and capacitor/s, C.

  • S. N. Ojha added an answer:
    Why is aluminum not extracted from alumina by pyrometallurgical operations?
    .
    S. N. Ojha · Indian Institute of Technology (BHU), Varanasi-221005, India

    Thermodynamically, carbothermic reduction of alumina occurs around 2100 0C. At this temperature more that 30% Aluminium gets vaporized and the remaining form carbides. Consequently the recovery is extremely poor. The reduction temperature although can be lowered by using other metals but  the process will be expensive.

  • Alain Celzard added an answer:
    How does regenerated cellulose membrane filter differ from A4 paper?

    A4 sheet paper is also made from cellulose.is there any processing done to make it filter and transparent (RC membrane)as well?

    Alain Celzard · University of Lorraine

    I agree with Paavo. Not only the regenerated cellulose is pure by definition (whereas that of paper is not purified and full of fillers intentionally added for improving mechanical properties and aspect, in addition to the natural impurities of wood), but the crystal structure is also different: cellulose I for native one, cellulose II for regenerated one. Native cellulose also contains a significant amount of amorphous parts, regenerated cellulose much less.

    Alain

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