Science topics: ChemistryCarbon
Science topic

Carbon - Science topic

A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight 12.011. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.
Questions related to Carbon
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How can I obtain a pyrolytic graphite (pyrographite) film or bulk from pyrolytic carbon (pyrocarbon) film or bulk?
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Read the paper (link mentioned below). Let me know if still its not clear.
Thanks.
Shahi Riaz
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How can I connect a carbon paper electrode to a platinum wire in the open air-cathode MFCs?
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Dear chandrasekhar
may be you can use a conductive epoxy to bind the carbon paper and platinum wire as the conductive epoxy may not effect the carbon paper resistance and conductivity. :)
 
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How we can generate Graphyne and Graphdiyne structures? Is there any web for it ? (as like tubegen for CNT)
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Here is a recent article entitled "New materials graphyne, graphdiyne, graphone, and graphane: review of properties, synthesis, and application in nanotechnology".
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I am looking for a laboratory that can perform chemical analysis of austenitic stainless steel samples to determine total and insoluble carbon and nitrogen.  Please suggest a best techniques and suitable laboratories. 
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I have been asked about this analysis. Any day now I will get information. Send email adress via RG.  
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I'd need to purchase some activated carbons. Ideally, I would need two different type of products, a carbon having high micropore volume (d<2nm) but possibly with most of pores having diameter lower than 0.7 nm (ultramicropore volume), and a second one mainly mesoporous (with most of pores having 2 nm<d<50 nm).
I would like to test their CO2 adsorption capacities and compare them with those achieved by using my carbons.
Could you recommend any companies (possibly in UK) which might provide suitable products?
Thanks,
Antonio
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AAC Eurovent Ltd
Registered Company Address
Unit K, Maybrook Industrial Estate, Maybrook
Road, Brownhills, WS8 7DG, England
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Some people use, in three cell electrode, electrodes made from the same material? For example carbon steel is used as working, counter and reference electrodes rather than using carbon steel as a working electrode and using Ag/AgCl as counter and reference electrodes.  How does this effect the corrosion measurement? Will the corrosion rate be the same in both cases?
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If you don't care about the actual value of the measured potential it is OK to use carbon steel as your reference electrode since in general most of your measurements are start at a potential with respect to the open circuit potential.  You just need to assume that your carbon steel reference does not shift significantly during the experiment.  This can be a problem if the solution composition changes drastically due to corrosion products.
That said for the best measurements (including for publication) you should use a proper reference electrode
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See above
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Hi, Nima,
Typically, the EDS overall accuracy is approximately 1wt% and the sensitivity is approximately 0.1wt% for all elements it is capable of detecting. However, from my experience at least, there is a lot of inconsistency when you try to measure C content on steels, especially low carbon steels. In many SEMs there appears to be an unavoidable contamination of the internal walls of the vacuum chamber with carbon, especially if you inspect organic material as well. You can get carbon peaks on everything, including aluminum alloys, etc. I know a lot of people just disregarding the carbon data (some just put “sample coated with carbon” by default), or account for a known bias (the bias can be of a few percents sometimes). Of course it all depends on what type of SEM you have, with or without vacuumed antechamber, etc. There are instruments that can clean the chamber and therefore make your measurements more accurate, but after a relatively short while you need to clean it again.
Fluorine and sodium don’t have the same problem as carbon, but be aware of the F K alpha overlap with Mn L alpha and Fe L alpha. Sodium overlaps with Zn, but since you don’t have Zn in the steel composition, you don’t have to worry about.
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I am working on the carbon export in the equatorial Indian Ocean and want to know the proper definition for both 
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In my opinion one should refer to the SCM in the upper surface waters occurring at 1-5 m depths, because right at the surface light intensity and temperatures can be too strong/high (too much UV, radical stress). In this case one can recognize in the upper water layer just below the surface a minor small increase in algal biomass and therefore increased fluorescence in the subsurface. In contrast the DCM usually refers to deeper water layers, where light intensity is much lower and then the DCM approximately coincides with the physical/abiotic features such as the pycno, thermo-, and nutricline. In (sub-)tropical oceans the DCM is often found between 40-100 m depths. However, both terms appear to be referring to the maxima in fluorescence at depths. I guess it is boiling down to a semantic differentiation and discourse.
Why has polymer grafted on the glassy carbon surface detached after continuous scans using CV?
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Hello everyone. I have a question about glassy carbon surface modification. I had successfully immobilized the Zn porphyrin complex onto GC surface. However, when I tested the stability of the polymer using CV (modified GC in TBAP for 50 cycles), all the polymer detached from GC surface.Please help me solve this problem. Thanks in advance
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Could you please let me know what is your electrochemical window?
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I would like to know the about  the recent research on Hyperfullerenes with highest number of elements ( be it Carbon or any other)
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Do you mean atoms at the vertices or also endohedral trapped atoms within?
Anyway it seems theoretically there should be no limit- if you increase the radius you can make any number of C atoms at vertices. But whether in practices such higher fullerenes remain stable or self sustained above say C=84 or somewhat larger is the question. The cage will no longer remain spherical or semi-spherical but will flatten like a normal 3-D stuff if you increase the number. What critical number will sustain a cage like structure depends upon apart from atom-atom interactions, but also masses of atoms involved.
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I have measured the scattering parameters of carbon matrix in GHz frequencies, results indicate the dielectric constant is very high
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M. ESSONE MEZEME, S. EL BOUAZZAOUI, M. E. ACHOUR, C. BROSSEAU, Dear Hong, See my paper
"Uncovering the intrinsic permittivity of the carbonaceous phase in carbon black filled polymers from broadband dielectric relaxation", J.Appl.Phys., 109, 2011, 074107(1)-074107(11).
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Kindly let me know of any revised version of these methods since am citing it and am told its too old.
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Dear Vincent,
take a look to the recently published papers
Jha et al (2014) Predicting Total Organic Carbon Content of Soils from Walkley and Black Analysis. Comunications in Soil Science and Plant Analysis, 45:713–725.
Lettens et al (2007) Variable carbon recovery of Walkley–Black analysis and implications for national soil organic carbon accounting. European Journal of Soil Science 58:1244–1253.
Hope this is of use to you.
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Except chemical vapour deposition method.
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we had used extrusion method to produce the lead coating on glass fiber and carbon fiber,about electrodeposition, I rearly do not know. 
Can anyone suggest a method that selectively adsorbs urea from human urine?
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Currently I employ bio-sorption using coconut shells which have given me very promising results; however, if one has to increase selectivity of urea in the process of nutrient recovery from urine, bio-sorption/adsorption would become redundant and unusable as it is non-specific. The internal structure of the coconut shells after characterization studies revealed a large number of compounds to be adsorbed on the sorbent surface. Could anyone suggest methods other than biosorption or any method that increases the specificity of the biosorption process?
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Yes. The property of biosorbent is to remove any solid particles so that coconut shells remove not only urea but also others. This work can be extended to other biosorbents whose biosorption is specific to urea. Also, extensive research on biosorbents is required to conclude this work. Everybody knows that research is continuous searching for knowledge.
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I think graphene is converted to GO in alkaline solutions.
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Dear Sridhar
thanks for your answer.
regards
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Is there an equation that allows you to estimate this parameter?
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 I assume that you are referring to soil organic carbon stored in peat. There are several approaches to calculating peatland carbon pools depending on the spatial scale and purpose of the estimate.  The peat C pool is calculated: peat volume (V)  x carbon density (CD), where V=area x thickness (usually expressed in m3) and CD= bulk density (BD; expressed as g/cm3 or kg/m3 ) x Carbon fraction  (i.e. 50% C = 0.5 carbon fraction).  Field measurements include peat thickness to determine volume and peat soil sampling to determine BD and %C in a laboratory. C stocks are usually expressed as MgC/ha.  Depending on the system you are working in, there could be enough information available to use default values for CD, and all you would need is an estimation of peat volume to estimate C stock- although this would be considered a less precise estimate. Land use history and biophysical factors can have a large influence on both BD and %C, so it is important to recognize the limitations of default values.  Please see attached paper and references within for more information. Though it pertains to tropical peat, the principles are the same for higher latitude peatlands. There is also a rich body of literature for higher latitude peatlands which covers different aspects of this topic.
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Some of my received MWCNT showed 2G and D+G band in their Raman spectra? Is that normal? Or those MWCNT have already been damaged somehow?
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The D+G band is a defect activated process as the D-band is. There you notice a correlation between the D-band intensity and the D+G intensity as it requires a defect for an elastic scattering event to provide momentum conservation in the Raman-process. The 2D-band however is a fully allowed process in graphene as it utilizes the same phonon twice (forward/backward scattering) to provide momentum conservation and hence will not require a defect for its activation. I am not an expert in multiwalled CNTs but I would assume that similar effects as we known them from graphite/few layer graphene are in place. Here the amount of interacting walles will have a great influence on the possible transitions and hence will dampen the signal intensity the "thicker" your MWCNTs get. This picture is a little simplified though as for CNTs due to their curvature you will have a lot more possible bands for electrons to scatter to from the beginning.
Another aspect that will reduce 2D-band intensity is destruction of the bandstructure by introduction of defects and hence amorphization. This is well studied in the breakdown of the 2nd order spectrum of graphene upon ion-bombardment, covalent functionalization or just oxidation. The more sp3-centers you incorporate, the more defects you have, the higher the D-band - up to a certain point (approx. 3 nm mean free path between 2 defects). Beyond this critical density the whole spectrum breaks down, signals broaden, 2nd order spectrum vanishes and the spectrum you will obtain mimics that of amorphous charcoal.
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I have a "carbon powder" and I want to know if it is carbon or graphite. How can I check it?
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All forms of carbon (except pure sp3 like diamond) contain some fraction of sp2 carbon, i.e., graphite. This graphite may however only be arranged in a 2D sheet like geometry, not in a 3D crystal. X-ray diffraction and Raman spectroscopy give you an average value of G and D forms, but you can use crystallographic interpretations to calculate the crystallite size. If you have access to HR-TEM, image your nano particles. Yet another simple experiment is to measure the electrical conductivity of your material and see how close it is to graphite.
About keeping it in the furnace- porous/ activated carbons (often with some impurities) react with O and burn- pure graphite is highly inert so doesn't burn. But if it has other materials mixed into it (for example polymers that may contain O or react with O) it may burn/ melt.
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I am looking for the database about herbs biomass. I need some average data about biomass (C and N) sequestered in entire plant, roots and shoots.
e.g.
Achillea millefolium
Alchemilla vulgaris
Anemone nemorosa
Angelica sylvestris
Anthriscus sylvestris
Asarum europaeum
Asperula odorata
Blackcurrant
Bryophytes
Vaccinium myrtillus
etc.
I need it to evaluate "plant biomass" of different sites, according to counted "plant units".
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This publication may help you:
also check if your library has the book:
Root Demographics and Their Efficiencies in Sustainable Agriculture, Grasslands and Forest Ecosystems
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Is this about steric factors?
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A bond between sp3 and sp2 is stronger than a bond between sp3 and sp3 because sp2 hybridized orbitals contains 33.33% s-character while sp3 contains 25% s-character. A general rule, the more s-character in a hybridized orbital, the stronger a bond it will form. Thus a bond between sp3 and sp2 with 33.33% + 25% % s-character will be more strong than a bond between sp3 and sp3 with 25% + 25% s-character.
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This is related to castings and why maximum operating temperature is limited to + 800 F.
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Perhaps this paper could be of some help.
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I have a 300 nm film of colloidal nanocrystal (ZrO2) with ligands (C24H51PO - TOPO) attached to it. I have done a different length of treatment on it to remove the organic part. Now I wish to measure the amount of carbon (average) left in the film, ideally I would like to have a depth profile of carbon.
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Dear Santosh, I am working in the field of hard protective coatings. If we need a precise chemical analysis we usually use ERDA (elastic recoil detection analysis). This method allows for a quantitative analysis with an error of ~1 at%.
Moreover you can perform depth analysis.
Another possibility for depth analysis would be SIMS (secondary ion mass spectroscopy). However for quantitative analysis by SIMS you need standards.
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See above.
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Dear amit
You can find it in reference book, but bellow link is useful
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A supplier for Pt and for Pt on carbon cathode for MFC/MEC.
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pCO2 indirectly calculated by total alkalinity, pH and Dissolved inorganic carbon. so based on these carbon species, can any one  suggest in this topic
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Hi!
I can also recommend the CO2calc software http://pubs.usgs.gov/of/2010/1280/
It has similar features and is free and user friendly!
Best Regards,
Leon
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The reason I ask is that we have a sample of pure C and I would like to compare.
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I don't have, but for sure this is something rather uncommon, as there is just nothing to see !! FT-IR spectroscopy allows to evidence surface functions, which are almost absent in pure graphite. Only C-H bonds exist at the carbon edges, but in negligible amounts compared to the amounts of C-C/C=C bonds in the bulk. So if your spectrum shows well-identified bands, you can be sure that it is definitely not graphite but a disordered (and probably porous) carbon full of surface functions. In the latter case only, FT-IR is a relevant method. For other cases, Ramal spectroscopy is far better and useful.
Alain
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I want to calculate the kinetics for my electrodes via CV, but the equations look very difficult. Is there anybody to help me out? Secondly, can you let me know about how could we know about the mass transport of the reaction, diffusion, migration etc using CV?
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@Gustav Karl Henrik Wiberg, I am interested in redox reaction for the analysis of Pb (II) ions in aqueous medium.
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Carbon sources
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I think you could try M9 minimal medium supplemented with different carbon sources (filtered stock solution). Good luck!
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I want to try to determine what is the content of free carbon in metal carbides powders, like TiC, B4C. Could anyone suggest what will be the best method to do this? Total carbon analysis (TCA) is not suitable, because I get whole amount of C. Any hints will be welcome.
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You can find the full description of non-combined carbon contents analysis especially for TiCx in the book: Samsonov GV (1962) Analiz tugoplavkikh soedinenii (The analysis of refractory compounds). Metallurgizdat, Moscow (in Russian), pp. 146-147. If you need it I can e-mail it to you in the form of .djvu-file.
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What am I generating at -4 V and NaCl (aq) solution using carbon (working electrode and counter electrode) and Ag-AgCl-KCl(sat) as reference electrode?
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Dear Almeshal ,
I just now realized that this questions is 4 year old, sorry
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In my gc ms experiment I have got long chain monomers  c15 to c19 while using linoleic acid as a carbon source in pseudomonas putida .Can p.putida capable synthesize long chain polymers?
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Dear  Dr. Ahil;
I hope it is not too late. The following attached book is an extremely important one in the area you are working in. Regards
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I want to optimize four carbon and nitrogen sources along with pH, Temp, incubation time and size of inoculum. I am using design expert version 9. Is there any option through which all of these can be optimized at one time. Kindly help me with this.
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As Dr JK Saini said it is better to be optimize the physical parameters like pH and temperature should be done by one-factor-at-a-time method. Then use PBD for the carbon, nitrogen sources or mineral salts etc. There are rules for PBD matrix making, which can be downloaded from net n u can do the matrix by own also by preferring the rules. All d best.
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I am learning about graphene and graphite formation.
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In no way, unless you expect conscious behavior of carbon atoms :)
I would look on the problem from the other side: C atoms can have 2 (linear), 3 (flat with 120 deg between bonds) or 4 (tetrahedra) fold coordination and thus can sit in the line, in the flat or in the volume. When 3-fold coordinated atoms occasionally happen to be in a large quantity we call it graphene.
People have invented a number of methods to increase the probability of this process, CVD on Cu for example.
How can I determine the value of SIC?
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Can I get the soil inorganic carbon data by substracting soil organic data (measured following the Walkley and Black method) from carbon data which are analyzed using an elemental analyzer? 
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I would suggest to determine firstly the total carbon with elemental analyzer then destroy the mineral carbon using acid (I suppose that your inorganic carbon is basically carbonate. Then analysis the samples (or subsamples) again and you will get SOC. The difference will be the SIC between total C and SOC will give you SIC. 
Why electrical properties of CNT differ along zigzag, chiral and armchair?
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CNT consists of all carbons, then why depending on direction of rolling, electrical properties gets changed? 
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In simple form, we can understand Electrical property on any material is depended on the position of atoms due to that band formation are changed. All three types of CNTs have different position of atoms hence the different band formation.
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Currently, we are working in heterogeneous catalysis for biodiesel production using sonochemistry as energy source for transesterification reaction from jatropha oil, but what happen with the catalyst structure specifically mesoporous carbon used as support of La and Zn oxides? Anyone has investigated this topic?
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Dear Guerrero, F.,
Please refer the following literature for biodiesel production methods
Biodiesel Production with Solid Catalysts
Feng Guo and Zhen Fang ; Biodiesel – Feedstocks and Processing Technologies; 339-359  Edited by Dr. Margarita Stoytcheva; 2011
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Say, targeting carbon/ nitrogen cycling at watershed/hillslope scales?
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Can anyone give me some suggestions how can I measure the black carbon, organic carbon and elemental carbon from particulate matter with reference? How the black smoke carbon can be different from the black carbon?
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Whatever definition you use, be it black carbon, elemental carbon, or black smoke, depends on the way you are about to measure. Although each measuring method attempts to measure the same fraction of PM, it is the physical principles behind them which defer and make the results incomparable. If you use an aethalometer, the carbon is measured in terms of blackness on a filter material through absorption (hence it is defined as black carbon), while a themal/optical analyzer measures the carbon indirectly by combusting it and measuring the CO2 (hence elemental carbon).
I agree with Celzard that Raman spectroscopy could give you valuable information on the molecular structure of the carbon particles, but it wouldn't give you a way to express the fraction in a quantitative way.
If you have no aethalometer or thermal/optical device to your disposal, you can also measure the reflectance of the aerosol loaded filter and compare it with a blank one. This method was used in earlier times to measure the 'black smoke index' (hence another definition) and can be easily converted in units of black carbon. I recommend you read the article of P. Quicey at following url: http://www.sciencedirect.com/science/article/pii/S1352231007008187
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I would like generate amino functional groups on the surface of the carbon nanofibers, for increase the compatibility between epoxy matrix and carbon fiber.
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I don't know if it'll work, but the most obvious would be to use ammonia diluted in argon as the gas mixture for plasma treatment. Another possibility for creating amine groups, is creating as much as -OH groups as possible, through an oxidation followed by selective reduction, and treat the material in concentrated aqueous ammonia.
Alain
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Hi,
I want to measure total Carbon and Nitrogen in soil cores and was wondering how much this analysis costs. Any approximate number would be helpful.
Best wishes
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The costs of biogeochemical analyis depends on what specifically you want to do with the results, ie. how comlete you need the anaysis and it depends if you want this information for solids or liquids. So you need to be a bit more precice.  You can have a geochemical analysis of all of the elements ..  and if you have the sample of soil just the way you collected it , your costs would run between  400 to 600 , but you only have the major  constituents - on the other hand if you just want a rough idea of what is contained in a sample XRF analyis is much cheaper. If you want the microbial compents then you are looking at higher costs. Go to an analytical laboraotry site, and have a look , you will see what I mean for example Bachema or Sakatchewan Research council, analytical laboratory  http://www.swisstestinglabs.ch/en/companies/adressliste/bachema-ag.html   http://www.src.sk.ca/facilities/pages/environmental-analytical-laboratories.aspx
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My student found this feature in the Cretaceous clayey paleosol. The outer shell is rich in carbon and the inner part is composed of pure clay. As a clay scientist I have no experience with this kind of features and can only guess that it is of biological origin. If someone has experience any suggestion is highly appreciated.
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It looks to me like soot coating clay particles. These are common on the Cretaceous- Tertiary boundary the result of the huge forest fires after the meteorites hit the Earth. It is a great finding!
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Can anyone give me the details of fatigue properties (S-N table or diagram) for Medium Carbon Steel AISI 1037?
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The suggestion (attachment)  from Manohar Sehgal is covering low to high cycle fatigue data on smooth and notch samples in bending fatigue (as far as I can read from his attachment). Please be aware that fatigue S-N curves data for low-medium carbon steels are  dependent on:
- test method (bending, axial..). The data given by Manohar is only valid for bending with given notch factors/smooth specimen data. Axial S-N curves will be different.
- Severity of the notch (e.g. notch sensitivity/stress concentration).
- Load frequency (usually lower level of the S-N curves at lower
frequencies due to the influence of corrosion fatigue).
- Ambient air humidity. High humidity combined with lower frequencies give lower S-N curves. If the notch is relatively sharp, the negative effects of low load frequency and high humidity can give un-normal data because the S-N curves are dominated by Stage II crack growth and adjoining crack closure..
- load ratio (R- ratio)!!!
- Processing condition of the actual steel, e,g. what temper condition, what microstructure and grain sizes, what inclusion size distribution level, etc.
Good luck and best regards,
Hans
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I have carbon and oxygen isotope data from a Proterozoic sedimentary carbonate section that shows a negative correlation. I wonder which process/es or factors can introduce this relationship between carbon and oxygen isotope. Any idea?
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The simplest answer is mixing diagenetic effects. A high-t fluid flow from organic-poor sedimentary carbonate (low d18O, normal marine d13C) and a low-T meteoric water influx (high d18O, low d13C). Bulk analyses would mix the two with varying mixing ratios in different samples, so you'll see a negative correlation.
The interpretation would also depend on the actual isotopic compositions.
Attila Demeny
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Biochars are thought to be a very stable form of carbon, yet normal CEC measurement (e.g., Neutral 1 M ammonium acetate) would yield very high CEC values (ranging from 15 - 40 cmolc/kg). Where are the sources of this CEC? Some people suggest that  the surface, oxidized carboxylate and phenolate groups are the probable source, but I am not quite convinced!
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The reason for high cation exchange capacity on biochars is twofold: Firstly, there is an increase in the surface area after pyrolysis. Secondly there is an increase in charge density on the surface. Generally, the higher the pyrolysis temperature the higher the biochar surface area. This high surface area is in the form of micro/nanopores as you correctly suggest.
However, it is not true to say that the ions (e.g. NH4+) are tightly trapped so that they cannot be flushed out. For the ammonium ethanoate method of measuring CEC to work the NH4+ ions must be flushed out with NaCl.If the ions are not exchanged with Na+ then they are not included in the CEC measurement. I see no reason why a physical trapping of ions that prevents flushing with alcohol or water would allow flushing with NaCl. Therefore, any elevated CEC measurement on a biochar must be due to adsorption on the biochar surface.
Biochars produced at low pyrolysis temperatures have a high number of oxygenated functional groups (carboxyl, hydroxyl, phenol etc) and dorption primarily occurs by chemisorption. However, biochars produced at higher temperatures have a higher C:O ratio and a higher degree of aromaticity. Sorption of metal cations to high temp biochars occurs primarily due to electrostatic physisorption (carion-pi interactions).
For further reading see:
Gomez-Eyles, J., L. Beesley, E. Moreno-Jiménez, U. Ghosh and T. Sizmur. 2013. The potential of biochar amendments to remediate contaminated soils. In: N. Ladygina and F. Rineau, editors, Biochar and Soil Biota. CRC Press, Boca Raton, FL
Does anyone have any article or review regarding effects of acidifying biochar on the biochar characteristics itself?
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I am currently working on using acidified biochar on agriculture, however, I have a difficulty in looking for articles regarding my research interest.
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I have my friend who has been working his PhD on biochar at Cornell University. He is now completing his research and hope he can help you. His email: hkb24@cornell.edu
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The gromacs manual says that the order parameter is calculated by inputting the angle between a vector and the z axis into an equation. So, if I would like to calculate the order parameter of the carbon backbone of polystyrene, is it true that I have to create two separate groups containing two different types of carbon atoms in the index file (because in one repeat unit of PS, there are two different carbon atoms)? And if it is so, will the final result show a plot of the order parameter as a function of distance in the z direction?
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You need as many index groups as you have carbons in the chain.  That will be many more than just two.  The order parameter for carbon N in the chain is determined from a local axis of the carbon at positions (N-1) and (N+1).  Thus every carbon in a chain is unique, even if they have the same atom name.  Name is irrelevant; chain position is what matters.
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An implication of this modelling study is that the net export of carbon at intermediate depths to the open ocean increases as the shelf seas grow and in particular as the area of the stratified shelf seas increases.
Is there a proxy which could be used, possibly from the sediments across the shelf break to test this idea?  
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Many thanks for your prompt response. Excuse a Physical Oceanographers ignorance - but how well is the ratio preserved on glacial-interglacial timescales?
I'd guess a good test of the idea put forward in our GRL paper would be to look at ratios in cores at the shelf break and see if they change as the shelves flood, and so test the idea that carbon export to the ocean increases as region subject to seasonal stratification grows.
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We have obtained a shoulder peak at high energy beside C-C bond peak from the XPS. We are assuming that it came from the bonding between Fe and C where C is sitting in the interstitial positions. I would appreciate your comment about our assumption.
Can we differentiate amorphous and crystalline carbon in iron lattice by any other method?
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By using XPS or other electron spectroscopies it is impossible to distinguish between crystalline and amorphous carbon. However, from the shape of carbon Auger peak C KVV (D parameter) it is possible to determine the ratio of sp2 : sp3 carbon, i.e. the ratio of graphitic and diamond-like carbon bonds. 
You can read more about this technique:
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Cities play an important role in social and economic activities. Cities generally perform poorly in terms of environmental performance (compared to social and economic activities). One of the main reasons behind this poor environmental performance appears to be due to population pressure and its impacts on the environment. Currently, about 50% population live in cities which is projected to rise in the coming years (by 2050 it could 6 out of 10 people will live in cities). Most of world megacities (> 10 million people) are in developing countries (e.g. Guangzhou, Shanghai, Jakarta, Seoul, Delhi, Mexico, Karachi, Manila, Sao Paulo, Mumbai, Beijing, Moscow, Dhaka, Cairo, Kolkata, Buenos Aires, Bangkok, Istanbul, Lagos, Tehran, Rio de Janeiro, Shenzhen and Tanjin) and few are in developed countries (Tokyo, New York, Los Angeles, Osaka, London, Rhine-Ruhr, Paris). The dense population in cities generate huge volume of solid and soluble wastes, the demand for electricity, water and traffic in cities will cause significant carbon footprints and water footprints. What measures would be needed so that cities remain a healthy place to live on in terms of managing carbon pollution and water pollution in the future?
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Dear Rogerio,
it is also my opinion, that the agriculture in industrial countries is not social and not sustainable , therefore I cited the tiny group of organic farmers who are often opposed and get difficulties.
The western lifestyle uses resources of more than one planet.
Moreover, cities perform badly in many repects.
Nearly half the world population are small farmers mainly in Asia and Africa. Education and health services for them are more difficult to establish, but not impossible and need not increase the low GHG emissions in these countries.
The Global Report (Agriculture at the Crossroads) critisizes inappropriate policy interventions, socioeconomic exclusion and the failure to address the real needs of poor people, recommending agro-ecological small-scalle farming, balancing beetwen economy and ecology - scaling up socially and environmentally sustainable practices.
Large cities are also more vulnerable, if the supply should be interrupted.
Their rapid growth is not well planned. Why not favor cities of more moderate extension ?
If cities are planned completely, they may perform perfectly for a while ecologically, but only for the period of time, where the planning conditions are not changed to much.
Thus, many aspects are important - also the balance between a sufficient size of the population and the impact on the environment.
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Activated carbon is treated with gaseous ammonia at 800C for 8 h. Elemental analysis showed an increase in nitrogen content from 0.5 to 2%. The BET surface area decreased form 1400 to 1320 cm3/g after treatment.The CO2 adsorption capacity was measured at atmospheric pressure, 25°C and 30% CO2 in nitrogen gas using a fixed bed reactor.
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Smaller adsorption capacity: in the gaseous phase, I presume ? This is indeed related to the correspondin decrease of surface area, although such decrease is rather poor. However, adsorption in the liquid phase may change significantly, as the impact of surface chemistry is much higher in such a case. I expect that adsorption of weak acids, such as phenols, will be enhanced because of the increased basic character of the surface.
Alain
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I know that a mixture nitric/sulfuric (3:2) can be used, but how long should I immerse the sample in the solution? Is the temperature important? Is there any other method?
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I think Honoria Gorgulho offered the most effective option. In principle this can be done in the air. The removing of graphite at temperatures of 400-500 ° C will be more effective. You can also use hydrogen plasma. Сhemical methods are not very effective.
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I will use a pump to evacuate the furnace, here is the problem.
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You can use 5% H with 95% Ar. That's much safer.
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I want to pass 150 kg/hr chlorine gas from activated carbon so what diameter column will do ?
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I am currently doing my project on something similar and have found that if you use volumetric flow rate and interstitial velocity to calculate area then you can deduce the column diameter from this area.
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Or how to make carbon cloth? I would like to prepare carbon paper.
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To deposit carbon on cloth you can try filtration of a carbon black ink on a carbon cloth. Or screen-printing as well.
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Seeking to functionalize N- & S- groups on activated carbon surface with strong bond give reference
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Dear Senu,
Concerning N-groups I recommend you AC reaction with urea at 623K under air atmosphere.
Please, see the paper 'Hydrogen uptake of high surface area-activated carbons doped with nitrogen' in my RG profile.
V
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I am planning to simulate carbon electrodes and cyclic voltammograms. What are all all the software commercially available to simulate electrodes
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Thank you sir
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While carbon nanotubes (CNT) and carbon nanofibers (CNF) are both hollow (in case of hollow carbon fibers), nanometer in scale, and produced in a similar manner, there are distinct differences which significantly impact their performance and ability to be processed.
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This is a question of size. Carbon nanotubes can be single-walled, but also multi-walled, but are those having the lowest diameter and the most defectless structure. Carbon nanofibres are much bigger, thus sometimes loose the concentrical structure, and also they can have a number of defects which are mostly absent from nanotubes. Hence the outstanding mechanical properties of nanotubes, especially the single-walled ones. Carbon fibres are even bigger (diameters of a few microns), are thus more disordered, less oriented, with more defects, etc., hence their lower mechanical properties (which can remain quite high though).
Alain
Where can I buy carbon fibres with a small diameter (less than 1 µm)?
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Does anyone know a supplier of carbon fibres who can deliver fibers or fibre fabrics with a diameter of less than 1 µm?
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Hi Falko, I would be very happy if you contact our lab to get your desire carbon nano/micro-fibers. We (our research family) have also a company called 'Espin Nanotech' for electrospinning machine by which you can produce tons of fibers of your need. you can log on to the link below: http://www.espinnanotech.com/
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Are there any sample preparation for specific surface area measurement?
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I wonder BET analysis can measure graphene
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Carbon at different altitudes.
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As altitude effect biomass so c stocks effected
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I've browsed some publications, but few mention the details like the concentration of the agent, temperature, etc. Can anyone provide suggestions or a protocol?
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Hi,
These functional groups are formed in more or less severe conditions, as they are more or less stable. I would not prepare them directly by electrochemical oxidation, as the potential for forming them is indeed prone to change, depending on the carbon texture. I would instead oxidise as much as possible, thus forming all possible oxidised functions. For that purpose, concentrated H2O2, HClO or HNO3 in water all work well. Then, a heat-treatment in nitrogen at increasingly high temperatures first makes carboxylic acids evolve, followed by carbonyls at higher temperature, followed by hydroxyls at the highest temperature. But it is extremely difficult to have one single kind of moiety remaining at the surface. Except for -OH groups, for which oxidation, evolution of carboxylic acid, and selective reduction by NaBH4 in dry solvent works very well (see attachement).
Alain
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Yah i gave already tried but its not working with keto enol tautomer so still looking for another option ,thanks
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I know that there will be temperature dependence and possible dependence on which Cp based precursors you are using, but in general if you start with a -OH surface and pulse a cyclopentadienyl precursor will and how does it react with the surface group? What would the by-products be? CO CO2?
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Hello Keith,
While the reaction products will depend on the thermodynamic parameters at given experimental conditions (temperature, pressure, etc), I believe the product after an exposure of Cyclopentadienyl (Cp) precursors to a substrate with surface hydroxyl (-OH) group, will generally be CpH.
One of the good references to look into will be 'Atomic layer deposition of MnO using Bis(ethylcyclopentadienyl)manganese and H2O' by Burton et al. (http://goo.gl/sh06rU) which includes a thermodynamical calculation as well as FTIR study to study the ALD reaction mechanism of MnO from Mn(CpEt)2 and H2O.
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I am trying to prepare carbon from polymers by the carbonization technique. On carbonization, I am getting ashes on the top of the carbon. Is there any method to avoid it or how can I separate this ash from the carbon?
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Dear Ajit,...
the comments of Palash are correct.
Every polymer, when carbonized at temperatures higher than 1000°C within inert atmoshere, does show a carbon yield in between nearly zero and up to 50-70% of original starting weight. This yield normally is in between 10 and 80 % of the theoretical carbon content of the polymer structure (amount of carbon atoms).
Polyacrylonitril has about 50% carbon yield and phenolic resin about 80%.....
There are some possibilities in pretreatment (Polyacrylonitrile p.e. treatment in oxygen in between 200 and 300°C) to stabilize the polymer structure...which is important to get a good carbon structure.
Here my question:
What is the goal of your scientific work?
Which kind of carbon structure you want to get?
Which polymers you have tested up to now?
What is your carbonization procedure (temperature, residence time, atmoshere)?
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I want to prepare activated carbon with high surface area from coconut shell by chemical activation.
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This is very easy and well documented: just use alkali hydroxides, not H3PO4. KOH is generally more efficient than NaOH. The most important parameter is the KOH/precursor weight ratio, followed by activation temperature. Probably values of 3 - 4, and 750 - 800°C, respectively, will be OK. Take a look at our publications in my RG profile.
However, pay attention to the literature: this has been done for long, as coconut shell is a very popular activated carbon precursor. Publishing that might be very difficult.
Alain
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Purification of cellulase from a source
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There are many c-sources like u can use banana peels, banana leaf, sugarcane bagasse, ground nut shell, wood chips, corn cob, wheat straw, coconut coir etc. I am working on all the above substrates and the best one is banana peels for bacteria and sugarcane bagasse for fungi. Hope u will be benefited from this.
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How do you calculate fixed carbon in biomass?
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According to ASTM D3172 method, proximate analysis is~
Moisture content: 105 degree C for 2~3 hr using an oven
Volatile content: 925 degree C for 7 min using a furnace
Fixed carbon: 800 degree C for 3hr using a furnace
100 (%) - M.C (%) - V.C (%) - F.C (%) = Ash content (%)
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Previous studies by Wattel-Koekkoek and Buurman (2004) on carbon turn-over rate and mineral association revealed that Kaolinite-associated SOM had a relatively fast turnover time of 360 yr on average while smectite-associated SOM had a slower turnover with an average mean residence time (MRT) for the whole clay-size fraction of 1100 yr. Differences in turnover time were significant and were associated to the clay mineralogy. However, structural characteristics of organic matter in whole clay fractions can vary between different soil types (Balesdent and Mariotti, 1996; Wattel-Koekkoek and Buurman, 2004; Kögel-Knabner, 1997).
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This is a tricky question because the answer involves the consideration of several variables. The first two variables:
(i) if it is a 2:1 or 1:1 type of clay and
(ii) if you are considering humus, humic acids or fulvic acids.
Clays are mostly made of silica and aluminum hydroxide. If its configurantion is one to one of the former compounds you have a 1:1 type of clay. If you have two layers of silica around 1 layer of aluminum hydroxide you have the 2:1 type, which is the most likely to retain more organic material on the soil. The degree of “organic” retention will depend on the nature of the compounds (humus, humic or fulvic acids) and the structure of the soil. Humus is better retained in blocky soils and humic and fulvic acids on granular soil.
All this is the fundamental knowledge, but you need to build some practice to understand the effect of secondary variables such as water movements and surface dynamics.
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Since last one year I have been using 0.5 N FeSO4 titration method for detection of organic carbon from any organic material, but this method does not give accuracy or appropriate results. Does anyone know a new method for detection of organic carbon?
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Combustion and then stoichiometry.
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I am interested in calculating graphene domain size values. I have reading that the D and G Raman band intensities ratio (ID/IG) can be used to calculate it.
What are the limitations of this calculation? What we have to consider on using it? Are there other kind of characterization techniques that provide similar approach?
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Yes, Raman is quite easy and you can also find online tools for that. You can also try e.g. XRD line profile analysis: the peak width give you an order of magnitude estimate and a modern technique like the Whole Powder Pattern Modelling can in principle give you some information on the domain size distribution
How does compare redox protein electrochemistry (i.e., cytochromes) on boron-doped diamond as compared to graphene-based electrodes?
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Problems of protein adsorption on electrode surfaces and inhibition of electron-transfer reactions.
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Due to conductivity of boron-doped diamond it should be no principal difference between carbon and boron-doped diamond? There is Review on HEME based redox proteins in biosensor and bio-fuel cell design:
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like VNSS medium contains 1.0g peptone, 0.5g yeast extract, 0.5g glucose per liter
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I think it is around 500mg/l. am I correct?
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Collodial carbon that goes to the lungs
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I've bought materials from Skyspring Nanomaterials and they were are able to disperse the particles I purchased. They produce both diamond and graphite nanoparticles. http://ssnano.com/inc/sdetail/graphite_nanoparticles/303
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I'm making a counter electrode using black carbon and Teflon® (9:1) using the brush painting technique onto a metal surface. I don´t know if this method is a good way to make high efficient DSSC and If it is a good alternative,
what do you suggest?
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I dont suggest brush coating technique for coating carbon films on metal. Doctor blade technique or even squege method (using glass rod) will give far better results. However, the slurry should be viscous enough. PVDF(Teflon)/Carbon is generally used for making electrodes for lithium ion batteries and is being recently adopted for DSSCs also. So, I think it is a good combination. In my work, I have used other solvents such as ethanol or ethanol:Nafion but CNTs/graphene had to be functionalized in order to be dispersed.
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This a reviewer question on an article of mine. The question was: "Even though the carbon is a major element, why its intensity of C247 nm much lower than that of Na 588, 589 nm lines (minor element) in the observed LIBS spectrum"?
My answer is; "Neutral carbon is usually not easily detected because of its low transition probability values compared to sodium. Moreover, carbon has much higher ionisation potential 11.26 ev and melting point 3773K compared to sodium (5.139 EV, 371K). So sodium is more easy to be represented in LIBS spectrum with much lower laser beam intensities than carbon."
Do you agree with my answer or do you have any other suggestions?
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Do you agree with my answer?
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In my opinion, dry ashing of the charcoal pellet is the best option and can be completed in 1 hr. As far as possible, toxic acids fuming should be avoided and is a health hazard. Perchloric acid (HClO4) is an extremely reactive liquid. It is clearly stated in ASTM document, Designation: C 25-06, Section: Procedure: Warning, page no. 6. quote “When using HClO4, there are precautions to be followed which, if unheeded, may lead to serious explosions. Contact of the hot concentrated acid with organic matter (AC in this case) must be absolutely avoided. Any organic matter in the sample must first be destroyed by the addition of nitric acid (HNO3) to the sample prior to fuming with HClO4. If proper care is not taken, wet-ashing treatment of charcoal pellet with HNO3 and HClO4 may result in a blast.
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The REEs are desorbed quantiatively from activated carbon, by completely oxidizing and solubilizing AC by wet digestion (HNO3 and HClO4 treatment ).
Thus the time consuming and tedious method of ignition of charcoal to ashes is avoided, to increase the sample throughput in geochemical exploration studies .
http://www.indianchemsoc.org/jour2013.htm, Abstracts of Journal of Indian Chemical Society Vol.90, November 2013, pp. 1919-2156 , V. V. Hanuman and G. Chakrapani, J. Indian Chem. Soc., Vol. 90, November 2013, pp. 1919-1924.This statement of the authors is absolutely wrong and highly misleading.
In my opinion, dry ashing of the charcoal pellet is the best option and can be completed in 1 hr.
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The RBM is only supposed to be for single-walled CNT.
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In order to understand the problem, could you present here the spectrum in the range ca. 100-1700 cm^(-1) and laser wavelength used in Raman spectrometer?
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There is a confocal Raman equipment at our lab. The full laser (633 nm) power is 25 mW. I am worried that too intensive laser would damage the tubes. According to experience, what are the appropriate parameters such as laser power and exposure time for CNTs.
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Really this can depend on the thermal contact to the substrate. In general, you can ease the thermal load for raman measurement by for example embedding the sample in a KBr disk, as is commonly used for FTIR spectroscopy
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Bitcoins and similar digital currencies have taken off recently because of an advance in Computer Science regarding how to do secure bookkeeping regarding the origin of a coin and all its transactions. The crowd maintains a record of who owns the coin so you can't cheat forge the currency and still participate in the market because your records will be out of sync with everyone else's. Coins can also be mined, or created, by performing complex computations to keep them scarce. The idea of carbon credit markets is to give countries and companies a certain amount of credits relating to the amount of carbon they are allowed to burn. To go over that limit without fines they would need to buy credits off countries that have a surplus because their energy is produced sustainably.
I wonder if the ideas behind digital currencies could be used to make carbon credit markets more dynamic and more liable to be used on a large scale. For example, what if a new digital currency was created for everyday use on the internet but is also tied to carbon credits. Countries could mine new coins in this currency via a combination of their percentage sustainable energy production and total carbon emmisions. I'm not sure if you'd need the algorithmic mining component at all. You just use the bookkeeping aspect of bitcoin and replace "Country has produced x% of their energy sustainably" as the "hard" function needed to mine coins.
Greener developed countries like Germany would be relatively richer in this currency but it would also be easier for developing countries to generate because their absolute pollution levels would be much lower. These countries could then sell these credits to other countries or individuals for use on the internet. They could give or sell at a discount to their own citizens thus rewarding them with some virtual income. This would essentially create a new economy that creates wealth where it is needed most while rewarding those who are making the world more sustainable.
I'm not sure if that is useful, but it seems to me there might be something there.
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Dear Mark! Your idea proves once again the development of the whole world in a spiral. I specify my idea. At some stage of the commodity exchange moved to intermediaries in the form of money. Now once again invited to the transition to a carbon form of goods. Sometimes in virtual form. And it is unpredictable in reality.
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See above
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Basically any carbon containing precursor can be used for the prepration of activated carbon. There are two main methods, which can be classified as the chemical and physical, both using high tempertures (>500 oC). The chemical method can use adsorption of phosphoric, acid, zinc chloide, KOH, etc. while the physical can use water vapor, CO2, etc. In order to Control the burn-off protective attmsophere is used. After the thermal treatmentas, the chrred residue should be washed by dilute acids in order to remove ash componenets. If you want to prepare activated carbons it is better to follow the steps, which are well-explained in the literature.
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I have read about synthesis of carbon dots by various means like thermal and microwave mediated. Does anyone know a reliable method to synthesize carbon dots which have absorption maxima around or above 405nm?
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In my experiments, I am directly pyrolyzing photoresist (PR) in an inert or reducing gas to form a C film. I have deposited Cu via thermal evaporation (50 or 300 nm), before spin-coating the PR in order to ensure good electrical conductivity for later measurements. I've confirmed that, regardless of modifying pyrolysis temperature (700-900C), heating cycle during pyrolysis, Cu film thickness, or substrate (fused silica or single crystal quartz), the Cu film has de-wet from the substrate to form small spherical droplets after the pyrolysis has finished. How can I prevent the de-wetting of the Cu film? I'd prefer not to increase the Cu film thickness if possible
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It is a commonly observed phenomenon that metal films dewet from a silica or quartz substrate if heated above a certain temperature. This is due to the small attractive forces between the substrate and the metal, and the strong interaction between the metal atoms on the other hand. So at elevated temperatures, where the atoms get more and more mobile, the dewetted state is thermodynamically favoured compared to a thin film on the substrate.
What you may try to prevent this is to coat the substrate with a metal of a high melting point such as Cr or Ti, these metals are used to promote the adhesion of thin films on glass or silicon. If you deposit a film of about 5-10 nm, then this underlayer should stuck the substrate, and the Cu adlayer on top will be adherend to this basal layer.
I cannot guarantee, but I think that this may improve the dewetting properties of the Cu, good luck, and keep us updated about the progress!
Dirk
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I have a 400 nm carbon film deposited via chemical vapor deposition on a fused quartz substrate. I need to remove half of the film to expose the underlying quartz substrate. Any suggestions would be much appreciated.
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Hi Megan,
In my experience, the most efficient way to remove carbon film would be to etch it in a high-density oxygen plasma using aluminium film as a mask. The high-density plasma is generated by ECR or ICP plasma sources with rather high radiation power (few hundreds Watts). Also, some small (10-20 Watts) of additional RF substrate bias will be needed to activate the etching process.
Unfortunately, this sort of plasma systems are not always available in a lab, so alternatively, you can try a good old ion milling with argon ions. This methods is more crude and can potentially cause defects in you substrate and/or film.
A regular capacitively coupled RF oxygen plasma has a very low etching rates for carbon films, and would take too long to remove all 400 nm of your film.
Good luck,
Andy
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There are hundreds of papers about Raman spectroscopy of carbon materials, whether the latter are graphites, disordered or diamond-like carbons, CNTs, graphene, etc. Therefore, to avoid missing important papers, I am looking for the very best, up-to-date, reviews, in which the most important things to know have been well explained and summarized.
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For the disorder and amorphous carbon I would suggest to follow A.C. Ferrari's papers. The following is the most cited one:
Ferrari, A. C.; Robertson, J., Interpretation of Raman spectra of disordered and amorphous carbon, Physical Review B (Condensed Matter and Materials Physics), Volume 61, Issue 20, May 15, 2000, pp.14095-14107. DOI: 10.1103/PhysRevB.61.14095.
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No matter what kind of carbon structures, I want to achieve to a carbon structure which can show hydrophilic behavior.
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Carbon is hydrophobic only if pure aromatic carbon layers are considered, such as graphite is made of. But the edges of carbon layers need to satisfy their valence, therefore many moieties can be found there. As far as these moieties are oxygenated, the carbon support becomes hydrophilic. And the effect increases with the number of edges bearing moieties, in other words, increases with the surface area. This is the reason why all activated carbons are hydrophilic and spontaneoulsy adsorb moisture at a leval equal to 5 - 15 % of their weight. So any carbon structure can be made more hydrophylic (or less hydrophobic) by oxidation. Treatment of carbon in hot concentrated nitric acid is very efficient, but also in concentrated hydrogen peroxide, in permanganate, or even in sodium hypochlorite. You can observe the efficiency of the oxidation by weighing the material before and after treatment. Oxidation leads to a significant weight increase.
Alain
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C12A7 transparent glass is an insulator. Thermal treatment in a carbon atmosphere can reduce this resistivity. I made this material with CS and heated it at a high temperature to transform it to a green-brown glass, probably with a great amount of clustered carbon.
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Carbon deposited by cracking a hydrocarbon atmosphere may indeed form a conductive film at the surface of any substrate. For removing it, simple calcination is the best method. Only heat in air your substrate, and the carbon will be oxidised in air in the form of CO (so doing inside a fume hood is required). 900°C should be high enough. I do the same for cleaning the ceramic tubes in which pyrolyses are carried out, and the tubes recover their white and clean aspect.
Alain
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.
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LFP is used for High Energy Lithium Ion Batteries for Automobile Applications since they have higher cycle life.
Basically 80-85 % of LFP is used and rest is PVDF and Activated carbon
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We need to realize a cylindrical capillary to validate reactive silicon infiltration simulations with experimental data.
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If you need just one or a few capillaries, you could try to use a focused ion beam (FIB) (it usually comes with a SEM, and allows micromachinning of your samples and SEM observations at the same time).
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I want to use methane as a starting precursor for graphene growth. At the same time, waste palm oil is utilized as a starting source for the formation of methane.
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Malaysia, a tropical palm tree growing country, generates millions of tons of waste palm biomass from its numereous palm oil mills.The Palm Oil Mill Effulent (POME),like municiple waste also produces CH4 which is used as a source for electrical/ thermal energy. Depending upon the concentrations of CH4 in the POME samples, the details of the methods applied are given in:
Science of the Total Environment, 366 (2006) 187-196.
Click:
Baseline study of methane emission from anaerobic ponds of ...
Starting from CH4, graphene can be obtained by:
“Graphene Synthesis and band gap opening”
By
Deep Jariwala, Anchal Srivastava and Pulickel M.Ajayan
Specially concentrate on the last paragraph of 9/33 page.
Click:
Graphene synthesis and band gap opening Table of contents:
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NB these are semiconductors.
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'Graphene quantum dots, also recognized as GQDs are disk of graphene in the size range of 2- 20 nm. They are fluorescent due to quantum confinement, surface defects and zigzag edges. GQDs are composed mainly of Sp2 hybridized carbon and they are crystalline. On the hand, Carbon dots (C-dots) are spherical carbon particles with a size less than 10 nm. They are composed mainly of Sp3 hybridized carbon, usually amorphous and they can show in XRD the (100) plane of the basal planar of graphite. Luminescence in C-Dots is due to surface defects, which explains why they quench in some medium. Also for my knowledge the difference is not much clear, if you want more information. Moreover, a lot of researcher confuse GQDs with C-Dots and other consider GQDs as a type of C-Dots. Therefore, you can consider them family of quantum dots made of carbon. Their quantum confinement is still not understood well and is not completely the same as for semiconductor quantum dots such as: CdS or CdSe. Because GQDs can have different size and same bandgap energy (i.e 3.4 eV), however, pristine graphene is 0 eV or close from 0 eV, that's why they are named as quantum dots when compared to graphene.
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Citations would be helpful, as I have been unable to find any papers which do not refer to the half-life of C-14 as "known", even though estimates vary, and the current consensus seems to have been determined by a committee.
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Many informations here :
doi:10.1126/science.140.3567.584
and there :
doi:10.1038/195984a0
Alain
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Using micromeritics surface area and porosity analyzer (ASAP-2020).
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Let's refocus: The question was "How to measure pore size distribtion of microporous carbons ?".
Measurements of BET surface area is not equivalent with measuring the pore size distribution. Moreover, the premises of BET calculation do not apply to microporous materials, because the mechanism of multilayer adsorption on random surface patches does not apply in micropores. For this reason, BET method for calculation of surface area from adsorption isotherms overestimates the results for microporous materials, However, the BET method is still used with these materials for the lack of a better method. It only gives a number (m^2/g) that is useful for comparative purposes for microporous materials (and others). But if the goal is to determine pore size distribution, then the DFT methods are regarded as the best choice available today. When using DFT (in any of its current variants, NLDFT or QSDFT) it is the researchers's task to select the geometry of pores (slit, cylindrical, or combinations of both, or others) in ther carbon. Moreover, the routines available for DFT calculationas are limited to a number of gas, material, and pore geometry combinations.
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How can doping of Ni and Pd affect intensity of G and 2D band in spectra?
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HI, yes one can dope graphene with metals. Depending on work function of metal graphene gets p or n-type. Signature of dopoing is shift in G and 2D peaks and it doesn't matter how its get doped; by means of organic or inorganic components. Even the shift in these two peaks is same for doping by transverse electric field. The following paper is more helpful:
Best luck
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I attached the supporting infomation detailing the fabrication of flexible supercapacitor using flexible carbon substrate. What is the difference between carbon fabric and carbon substrate in terms of their electrical conductivity?
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Hi,
The electrical conductivity dramatically depends on the carbon texture and on its porosity. At similar carbon texture, then the higher the density, the higher the conductivity. A fabric is a highly porous material, whose conductivity also depends on quality and number of contacts between the carbon fibres. The conductivity is thus strongly dependent on the pressure applied during the measurement. In contrast, the substrate is much less porous, maybe not at all, so its conductivity is expected to be much higher than that oif the fabric.
Hope it helps,
Alain
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I prepared a metal/carbon network via a solid state reaction. I want to remove the carbon (amorphous graphite) and leave the pure metal network. However, the melting point of the metal is lower, and the nano-scale microstructure of the metal is easily to be destroyed via a thermal treatment. So I really hope there is the way to remove the carbon mildly (under room temperature is the best, lol ).
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Well, it depends on how your metal network can resist oxidation. Carbon can be oxidised, but metal also. What is your metal ? I have seen in a paper amorphous carbon removal by treatment in H2O2 near room temperature, but I have not experienced it myself, so I am not sure it'll work in your case. And of course, depending on the nature of your metal, this way of doing can be inappropriate. Better checking the redox potential of your metal and compare it with the H2O2/H2O system, which also depends on the pH.
Alain
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Also, is there a difference between CNT, graphite and graphene based on Raman analysis? I am dealing with carbon nanomaterials.
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One of the way is to compare G and 2D band intensities- for graphene 2D band is much higher than G. The other way is to observe and calculate FWHM of 2D band. For graphene 2D band is sharp single line, for more layer 2D band become wider.
All is presented in Ferrari at al. Phys. Rev. Lett. 97, 187401 (2006) . In this article is also shown the difference between graphene and graphite.
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Especially I'm looking for solvothermal or a simple chemical method. I can't find any research paper about this.
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Here is a theoretical paper on K doping on CNT: Strain effects on work functions of pristine and potassium-decorated carbon nanotubes, J. Chem. Phys. 131, 224701 (2009);
The references and results in this paper may give you some ints on Li doping in CNT.
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I need information on the calculation of conversion of fossil fuels in carbon. Furthermore, I also need information on converting biomass of fish in carbon. Can anyone help me?
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For a rough estimate about emissions factors related to fossil fuels (oil, gas and coal) you can use the estimate of "Statistical Review of World Energy 2013" of BP (http://www.bp.com/en/global/corporate/about-bp/statistical-review-of-world-energy-2013.html)
However, these are for conventional fuels, if you want to assess also unconventionals you would need to make a deeper research. I recommend [Koppelaar 2009] (http://www.peakoil.nl/wp-content/uploads/2009/05/april_2009_less_oil_more_co2_aspo_netherlands.pdf)
good luck! hope it helps,
iñigo
Why does the SOC level affect Q10 for labile C pool?
Question
20 answers
My experiment showed that SOC level affected temperature sensitivity (Q10) for labile C pool. And for labile pool, the Q10 was higher for high-SOC soils than low-SOC soils. But I don't know how to explain the result. Could you help me? Thanks, Lujun
Relevant answer
Answer
This is almost impossible to answer without seeing details about setup and data. However, many potential problems may arise when determining the Q10 by incubation studies. This is well described in Davidson (2006). You may also take a look in my publication from 2012 "Processes of soil carbon dynamics", where you can find examples for what happens to Q10 calculations during incubations. Depending on the incubation time, the apparent Q10 may be lower due to depletion of this pool. This might be the case for your low SOC samples. However, pool-determination via curve fitting should solve the problem. If this is feasible also depends on your specific setup. Hope, this helps a bit.