WorldWideScience

Sample records for high carbonate content

  1. Method for creating high carbon content products from biomass oil

    Science.gov (United States)

    Parker, Reginald; Seames, Wayne

    2012-12-18

    In a method for producing high carbon content products from biomass, a biomass oil is added to a cracking reactor vessel. The biomass oil is heated to a temperature ranging from about 100.degree. C. to about 800.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to crack the biomass oil. Tar is separated from the cracked biomass oil. The tar is heated to a temperature ranging from about 200.degree. C. to about 1500.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to reduce the tar to a high carbon content product containing at least about 50% carbon by weight.

  2. Denuded zone in Czochralski silicon wafer with high carbon content

    International Nuclear Information System (INIS)

    Chen Jiahe; Yang Deren; Ma Xiangyang; Que Duanlin

    2006-01-01

    The thermal stability of the denuded zone (DZ) created by high-low-high-temperature annealing in high carbon content (H[C]) and low carbon content (L[C]) Czochralski silicon (Cz-Si) has been investigated in a subsequent ramping and isothermal 1050 deg. C annealing. The tiny oxygen precipitates which might occur in the DZ were checked. It was found in the L[C] Cz-Si that the DZ shrank and the density of bulk micro-defects (BMDs) reduced with the increase of time spent at 1050 deg. C. Also, the DZs above 15 μm of thickness present in the H[C] Cz-Si wafers continuously and the density and total volume of BMDs first decreased then increased and finally decreased again during the treatments. Moreover, tiny oxygen precipitates were hardly generated inside the DZs, indicating that H[C] Cz-Si wafers could support the fabrication of integrated circuits

  3. Denuded zone in Czochralski silicon wafer with high carbon content

    Science.gov (United States)

    Chen, Jiahe; Yang, Deren; Ma, Xiangyang; Que, Duanlin

    2006-12-01

    The thermal stability of the denuded zone (DZ) created by high-low-high-temperature annealing in high carbon content (H[C]) and low carbon content (L[C]) Czochralski silicon (Cz-Si) has been investigated in a subsequent ramping and isothermal 1050 °C annealing. The tiny oxygen precipitates which might occur in the DZ were checked. It was found in the L[C] Cz-Si that the DZ shrank and the density of bulk micro-defects (BMDs) reduced with the increase of time spent at 1050 °C. Also, the DZs above 15 µm of thickness present in the H[C] Cz-Si wafers continuously and the density and total volume of BMDs first decreased then increased and finally decreased again during the treatments. Moreover, tiny oxygen precipitates were hardly generated inside the DZs, indicating that H[C] Cz-Si wafers could support the fabrication of integrated circuits.

  4. Effect of alkali metal content of carbon on retention of iodine at high temperatures

    International Nuclear Information System (INIS)

    Evans, A.G.

    1975-01-01

    Activated carbon for filters in reactor confinement systems is intentionally impregnated with iodine salts to enhance the removal of radioiodine from air streams containing organic iodides. When a variety of commercial impregnated carbons were evaluated for iodine retention at elevated temperatures (4 hours at 180 0 C), wide variations in iodine penetration were observed. The alkali metal and iodine content of carbon samples was determined by neutron activation analysis, and a strong correlation was shown between the atom ratio of iodine to alkali metals in the carbons and the high-temperature retention performance. Carbons containing excess alkali (especially potassium) have iodine penetration values 10 to 100 times lower than carbons containing excess iodine. Both low I/K ratios and high pH values were shown essential to high efficiency iodine retention; therefore, conversion of elemental iodine to ionic iodine is the basic reaction mechanism. The natural high K + content and high pH coconut carbons make coconut the preferred natural base material for nuclear air cleaning applications. Studies show, however, that treatment of low potassium carbons with a mixture of KOH and I 2 may produce a product equal to or better than I 2 -impregnated coconut carbons at a lower cost. (U.S.)

  5. Highly ordered macroporous woody biochar with ultra-high carbon content as supercapacitor electrodes

    International Nuclear Information System (INIS)

    Jiang, Junhua; Zhang, Lei; Wang, Xinying; Holm, Nancy; Rajagopalan, Kishore; Chen, Fanglin; Ma, Shuguo

    2013-01-01

    Woody biochar monolith with ultra-high carbon content and highly ordered macropores has been prepared via one-pot pyrolysis and carbonization of red cedar wood at 750 °C without the need of post-treatment. Energy-dispersive spectroscope (EDX) and scanning electron microscope (SEM) studies show that the original biochar has a carbon content of 98 wt% with oxygen as the only detectable impurity and highly ordered macroporous texture characterized by alternating regular macroporous regions and narrow porous regions. Moreover, the hierarchically porous biochar monolith has a high BET specific surface area of approximately 400 m 2 g −1 . We have studied the monolith material as supercapacitor electrodes under acidic environment using electrochemical and surface characterization techniques. Electrochemical measurements show that the original biochar electrodes have a potential window of about 1.3 V and exhibit typical rectangular-shape voltammetric responses and fast charging–discharging behavior with a gravimetric capacitance of about 14 F g −1 . Simple activation of biochar in diluted nitric acid at room temperature leads to 7 times increase in the capacitance (115 F g −1 ). Because the HNO 3 -activation slightly decreases rather than increases the BET surface area of the biochar, an increase in the coverage of surface oxygen groups is the most likely origin of the substantial capacitance improvement. This is supported by EDX, X-ray photoelectron spectroscopy (XPS), and Raman measurements. Preliminary life-time studies show that biochar supercapacitors using the original and HNO 3 -activated electrodes are stable over 5000 cycles without performance decays. These facts indicate that the use of woody biochar is promising for its low cost and it can be a good performance electrode with low environmental impacts for supercapacitor applications

  6. Growth Mechanism and Origin of High s p3 Content in Tetrahedral Amorphous Carbon

    Science.gov (United States)

    Caro, Miguel A.; Deringer, Volker L.; Koskinen, Jari; Laurila, Tomi; Csányi, Gábor

    2018-04-01

    We study the deposition of tetrahedral amorphous carbon (ta-C) films from molecular dynamics simulations based on a machine-learned interatomic potential trained from density-functional theory data. For the first time, the high s p3 fractions in excess of 85% observed experimentally are reproduced by means of computational simulation, and the deposition energy dependence of the film's characteristics is also accurately described. High confidence in the potential and direct access to the atomic interactions allow us to infer the microscopic growth mechanism in this material. While the widespread view is that ta-C grows by "subplantation," we show that the so-called "peening" model is actually the dominant mechanism responsible for the high s p3 content. We show that pressure waves lead to bond rearrangement away from the impact site of the incident ion, and high s p3 fractions arise from a delicate balance of transitions between three- and fourfold coordinated carbon atoms. These results open the door for a microscopic understanding of carbon nanostructure formation with an unprecedented level of predictive power.

  7. Element fractionation by sequential extraction in a soil with high carbonate content

    International Nuclear Information System (INIS)

    Sulkowski, Margareta; Hirner, Alfred V.

    2006-01-01

    The influence of carbonate and other buffering substances in soils on the results of a 3-step sequential extraction procedure (BCR) used for metal fractionation was investigated. Deviating from the original extraction scheme, where the extracts are analysed only for a limited number of metals, almost all elements in the soils were quantified by X-ray fluorescence spectroscopy, in the initial samples as well as in the residues of all extraction steps. Additionally, the mineral contents were determined by X-ray diffractometry. Using this methodology, it was possible to correlate changes in soil composition caused by the extraction procedure with the release of elements. Furthermore, the pH values of all extracts were monitored, and certain extraction steps were repeated until no significant pH-rise occurred. A soil with high dolomite content (27%) and a carbonate free soil were extracted. Applying the original BCR-sequence to the calcareous soil, carbonate was found in the residues of the first two steps and extract pH-values rose by around two units in the first and second step, caused mainly by carbonate dissolution. This led to wrong assignment of the carbonate elements Ca, Mg, Sr, Ba, and also to decreased desorption and increased re-adsorption of ions in those steps. After repetition of the acetic acid step until extract pH remained low, the carbonate was completely destroyed and the distributions of the elements Ca, Mg, Sr, Ba as well as those of Co, Ni, Cu, Zn and Pb were found to be quite different to those determined in the original extraction. Furthermore, it could be shown that the effectiveness of the reduction process in step two was reduced by increasing pH: Fe oxides were not significantly attacked by the repeated acetic acid treatments, but a 10-fold amount of Fe was mobilized by hydroxylamine hydrochloride after complete carbonate destruction. On the other hand, only small amounts of Fe were released anyway. Even repeated reduction steps did not

  8. Effects of carbon content on high-temperature mechanical and thermal fatigue properties of high-boron austenitic steels

    Directory of Open Access Journals (Sweden)

    Xiang Chen

    2016-01-01

    Full Text Available High-temperature mechanical properties of high-boron austenitic steels (HBASs were studied at 850 °C using a dynamic thermal-mechanical simulation testing machine. In addition, the thermal fatigue properties of the alloys were investigated using the self-restraint Uddeholm thermal fatigue test, during which the alloy specimens were cycled between room temperature and 800°C. Stereomicroscopy and scanning electron microscopy were used to study the surface cracks and cross-sectional microstructure of the alloy specimens after the thermal fatigue tests. The effects of carbon content on the mechanical properties at room temperature and high-temperature as well as thermal fatigue properties of the HBASs were also studied. The experimental results show that increasing carbon content induces changes in the microstructure and mechanical properties of the HBASs. The boride phase within the HBAS matrix exhibits a round and smooth morphology, and they are distributed in a discrete manner. The hardness of the alloys increases from 239 (0.19wt.% C to 302 (0.29wt.% C and 312 HV (0.37wt.% C; the tensile yield strength at 850 °C increases from 165.1 to 190.3 and 197.1 MPa; and the compressive yield strength increases from 166.1 to 167.9 and 184.4 MPa. The results of the thermal fatigue tests (performed for 300 cycles from room temperature to 800 °C indicate that the degree of thermal fatigue of the HBAS with 0.29wt.% C (rating of 2–3 is superior to those of the alloys with 0.19wt.% (rating of 4–5 and 0.37wt.% (rating of 3–4 carbon. The main cause of this difference is the ready precipitation of M23(C,B6-type borocarbides in the alloys with high carbon content during thermal fatigue testing. The precipitation and aggregation of borocarbide particles at the grain boundaries result in the deterioration of the thermal fatigue properties of the alloys.

  9. Optimisation of the microporous layer for a polybenzimidazole-based high temperature PEMFC - effect of carbon content

    Energy Technology Data Exchange (ETDEWEB)

    Lobato, J.; Canizares, P.; Rodrigo, M.A.; Ubeda, D.; Pinar, F.J.; Linares, J.J. [Department of Chemical Engineering, University of Castilla-La Mancha, Av. Camilo Jose Cela, n 12. 13071, Ciudad Real (Spain)

    2010-10-15

    This work aims at studying the role of the microporous layer (MPL) in electrodes prepared for high temperature PBI-based PEMFC. The two main components of this layer are carbon black and a polymeric binder (Teflon). This work addresses the effect of the MPL carbon amount on the performance of a high temperature PEMFC. Thus, gas diffusion layers (GDLs) containing MPL with different carbon contents (from 0.5 to 4 mg cm{sup -2}) were prepared. Firstly, they were physically characterised by Hg-porosimetry measuring pore size distribution, porosity, tortuosity and mean pore size. Permeability measurements were also performed. The higher the carbon content was the lower both porosity and permeability were. Afterwards, electrodes were prepared with these GDLs and were electrochemically characterised. Electrochemical surface area (ESA) was determined and fuel cell performance was evaluated under different fuel and comburent stoichiometries, supporting these results with impedance spectra. This made it possible to see the benefits of the MPL inclusion in the electrode structure, with a significant increase in the fuel cell performance and ESA. Once the goodness of the MPL was confirmed, result analysis led to an optimum MPL composition of 2 mg cm{sup -2} of carbon for both electrodes, anode and cathode. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  10. Low carbon content and carbon-free refractory materials with high thermal shock resistance; Thermoschockbestaendige feuerfeste Erzeugnisse mit geringerem Kohlenstoffgehalt bzw. kohlenstofffreie Erzeugnisse

    Energy Technology Data Exchange (ETDEWEB)

    Brachhold, Nora; Aneziris, C.G.; Stein, Volker; Roungos, Vasileios; Moritz, Kirsten [TU Bergakademie Freiberg (TUBAF) (DE). Inst. fuer Keramik, Glas- und Baustofftechnik (IKGB)

    2012-07-01

    Carbon bonded refractories are essential for steelmaking due to their excellent thermal shock resistance. The research on carbon reduced and carbon-free materials is necessary to manufacture high quality stainless steels tending carbon pick-up in contact to conventional refractory materials. Further advantages are reduced emissions of CO{sub 2} and energy saving potentials due to better heat insulation properties. The challenge is to develop alternative materials with lower carbon contents but with the necessary thermal shock resistance. The Priority Programme 1418 funded by the German Research Foundation (DFG) concentrates on this problem. In this article two materials are presented. First, the carbon content could be reduced by nanoscaled additives resulting in better bonding between matrix and oxidic components. Second, an AL{sub 2}O{sub 3}-rich carbon-free material is presented showing a very good thermal shock resistance due to its designed microstructure. Finally, a steel casting simulator is introduced to test the new materials under nearly real conditions. (orig.)

  11. High-performance supercapacitors of carboxylate-modified hollow carbon nanospheres coated on flexible carbon fibre paper: Effects of oxygen-containing group contents, electrolytes and operating temperature

    International Nuclear Information System (INIS)

    Phattharasupakun, Nutthaphon; Wutthiprom, Juthaporn; Suktha, Phansiri; Iamprasertkun, Pawin; Chanlek, Narong; Shepherd, Celine; Hadzifejzovic, Emina; Moloney, Mark G.; Foord, John S.; Sawangphruk, Montree

    2017-01-01

    Although functionalized carbon-based materials have been widely used as the supercapacitor electrodes, the optimum contents of the functional groups, the charge storage mechanisms, and the effects of electrolytes and operating temperature have not yet been clearly investigated. In this work, carboxylate-modified hollow carbon nanospheres (c-HCN) with different functional group contents synthesized by an oxidation process of carbon nanospheres with nitric acid were coated on flexible carbon fibre paper and used as the supercapacitor electrodes. An as-fabricated supercapacitor of the c-HCN with a finely tuned 6.2 atomic % of oxygen of the oxygen-containing groups in an ionic liquid electrolyte exhibits a specific capacitance of 390 F g"−"1, a specific energy of 115 Wh kg"−"1, and a maximum specific power of 13548 W kg"−"1 at 70 °C. The charge storage mechanism investigated is based on the chemical adsorption of the ionic liquid electrolyte on the c-HCN electrode. This process is highly reversible leading to high capacity retention. The supercapacitor in this work may be practically used in many high energy and power applications.

  12. Chromium Extraction via Chemical Processing of Fe-Cr Alloys Fine Powder with High Carbon Content

    Science.gov (United States)

    Torres, D. M.; Navarro, R. C. S.; Souza, R. F. M.; Brocchi, E. A.

    2017-06-01

    Ferrous alloys are important raw materials for special steel production. In this context, alloys from the Fe-Cr system, with typical Cr weight fraction ranging from 0.45 to 0.95, are prominent, particularly for the stainless steel industry. During the process in which these alloys are obtained, there is considerable production of fine powder, which could be reused after suitable chemical treatment, for example, through coupling pyrometallurgical and hydrometallurgical processes. In the present study, the extraction of chromium from fine powder generated during the production of a Fe-Cr alloy with high C content was investigated. Roasting reactions were performed at 1073 K, 1173 K, and 1273 K (800 °C, 900 °C, and 1000 °C) with 300 pct (w/w) excess NaOH in an oxidizing atmosphere (air), followed by solubilization in deionized water, selective precipitation, and subsequent calcination at 1173 K (900 °C) in order to convert the obtained chromium hydroxide to Cr2O3. The maximum achieved Cr recovery was around 86 pct, suggesting that the proposed chemical route was satisfactory regarding the extraction of the chromium initially present. Moreover, after X-ray diffraction analysis, the final produced oxide has proven to be pure Cr2O3 with a mean crystallite size of 200 nm.

  13. Carbon fiber content measurement in composite

    Science.gov (United States)

    Wang, Qiushi

    Carbon fiber reinforced polymers (CFRPs) have been widely used in various structural applications in industries such as aerospace and automotive because of their high specific stiffness and specific strength. Their mechanical properties are strongly influenced by the carbon fiber content in the composites. Measurement of the carbon fiber content in CFRPs is essential for product quality control and process optimization. In this work, a novel carbonization-in-nitrogen method (CIN) is developed to characterize the fiber content in carbon fiber reinforced thermoset and thermoplastic composites. In this method, a carbon fiber composite sample is carbonized in a nitrogen environment at elevated temperatures, alongside a neat resin sample. The carbon fibers are protected from oxidization while the resin (the neat resin and the resin matrix in the composite sample) is carbonized under the nitrogen environment. The residue of the carbonized neat resin sample is used to calibrate the resin carbonization rate and calculate the amount of the resin matrix in the composite sample. The new method has been validated on several thermoset and thermoplastic resin systems and found to yield an accurate measurement of fiber content in carbon fiber polymer composites. In order to further understand the thermal degradation behavior of the high temperature thermoplastic polymer during the carbonization process, the mechanism and the kinetic model of thermal degradation behavior of carbon fiber reinforced poly (phenylene sulfide) (CPPS) are studied using thermogravimetry analysis (TGA). The CPPS is subjected to TGA in an air and nitrogen atmosphere at heating rates from 5 to 40°C min--1. The TGA curves obtained in air are different from those in nitrogen. This demonstrates that weight loss occurs in a single stage in nitrogen but in two stages in air. To elucidate this difference, thermal decomposition kinetics is analyzed by applying the Kissinger, Flynn-Wall-Ozawa, Coat-Redfern and

  14. Gel spinning of PVA composite fibers with high content of multi-walled carbon nanotubes and graphene oxide hybrids

    International Nuclear Information System (INIS)

    Wei, Yizhe; Lai, Dengpan; Zou, Liming; Ling, Xinlong; Lu, Hongwei; Xu, Yongjing

    2015-01-01

    In this report, poly (vinyl alcohol) (PVA) composite fibers with high content of multi-walled carbon nanotubes and graphene oxide (MWCNTs-GO) hybrids were prepared by gel spinning, and were characterized by TGA, DSC, SEM, XL-2 yarn strength tester and electrical conductivity measurement. The total content of MWCNTs-GO hybrids in the PVA composite fibers, which is up to 25 wt%, was confirmed by TGA analysis. The DSC measurement shows that the melting and crystallization peaks decreased after the addition of nano-fillers. This is due to the reason that the motion of PVA chains is completely confined by strong hydrogen bonding interaction between PVA and nano-fillers. After the addtion of GO, the dispersibility of MWCNTs in composite fibers improved slightly. And the tensile strength and Young's modulus increased by 38% and 67%, respectively. This is caused by the increased hydrogen bonding interaction and synergistic effect through hybridization of MWCNTs and GO. More significantly, the electrical conductivity of PVA/MWCNTs/GO composite fibers enhanced by three orders of magnitude with the addition of GO. (paper)

  15. High-temperature oxidation behavior of dense SiBCN monoliths: Carbon-content dependent oxidation structure, kinetics and mechanisms

    International Nuclear Information System (INIS)

    Li, Daxin; Yang, Zhihua; Jia, Dechang; Wang, Shengjin; Duan, Xiaoming; Zhu, Qishuai; Miao, Yang; Rao, Jiancun; Zhou, Yu

    2017-01-01

    Highlights: •The scale growth for all investigated monoliths at 1500 °C cannot be depicted by a linear or parabolic rate law. •The carbon-rich monoliths oxidize at 1500 °C according to a approximately linear weight loss equation. •The excessive carbon in SiBCN monoliths deteriorates the oxidation resistance. •The oxidation resistance stems from the characteristic oxide structures and increased oxidation resistance of BN(C). -- Abstract: The high temperature oxidation behavior of three SiBCN monoliths: carbon-lean SiBCN with substantial Si metal, carbon-moderate SiBCN and carbon-rich SiBCN with excessive carbon, was investigated at 1500 °C for times up to15 h. Scale growth for carbon-lean and −moderate monoliths at 1500 °C cannot be described by a linear or parabolic rate law, while the carbon-rich monoliths oxidize according to a approximately linear weight loss equation. The microstructures of the oxide scale compose of three distinct layers. The passivating layer of carbon and boron containing amorphous SiO 2 and increased oxidation resistance of BN(C) both benefit the oxidation resistance.

  16. Organic carbon content of tropical zooplankton

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, V.R.

    In the Zuari and Mandovi estuaries variations in organic carbon of zooplankton are 26.4-38.8 and 24-39.9% of dry weight respectively. Maximum carbon content of estuarine zooplankton is observed in November. Organic carbon in nearshore and oceanic...

  17. Effect of organic carbon content of the domestic bentonite on the performance of buffer material in a high-level waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Won Jin; Lee, Jae Owan; Kang, Chul Hyung [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-12-01

    The organic carbon content of the domestic bentonite have been measured, and its effects on the performance of buffer are analyzed. The total carbon content and the organic carbon content were in the range of 3160 to 3600 and 2400 to 2800 ppm, respectively. The aqueous phase equilibrium concentrations of total carbon and organic carbon in bentonite-water mixture were in the range of 25 to 50 ppm and 4 to 18 ppm, respectively. The results indicate that the effect of organic matter in the domestic bentonite on the performance of buffer material were insignificant. 33 refs., 15 figs., 10 tabs. (Author)

  18. One-Step Synthesis of Microporous Carbon Monoliths Derived from Biomass with High Nitrogen Doping Content for Highly Selective CO2 Capture

    OpenAIRE

    Geng, Zhen; Xiao, Qiangfeng; Lv, Hong; Li, Bing; Wu, Haobin; Lu, Yunfeng; Zhang, Cunman

    2016-01-01

    The one-step synthesis method of nitrogen doped microporous carbon monoliths derived from biomass with high-efficiency is developed using a novel ammonia (NH3)-assisted activation process, where NH3 serves as both activating agent and nitrogen source. Both pore forming and nitrogen doping simultaneously proceed during the process, obviously superior to conventional chemical activation. The as-prepared nitrogen-doped active carbons exhibit rich micropores with high surface area and high nitrog...

  19. High content of pyridinic- and pyrrolic-nitrogen-modified carbon nanotubes derived from blood biomass for the electrocatalysis of oxygen reduction reaction in alkaline medium

    International Nuclear Information System (INIS)

    Zheng, Jie; Guo, Chaozhong; Chen, Chunyan; Fan, Mingzhi; Gong, Jianping; Zhang, Yanfang; Zhao, Tianxin; Sun, Yuelin; Xu, Xiaofan; Li, Mengmeng; Wang, Ran; Luo, Zhongli; Chen, Changguo

    2015-01-01

    Graphical abstract: Display Omitted -- Highlights: •An ORR electrocatalyst was fabricated from blood biomass and carbon nanotube. •The N-CNT catalyst exhibits good ORR activity, methanol resistance and stability. •The pyrolysis process produces high contents of pyridinic and pyrrolic N species. •The pyridinic-N group may play more important role in the active sites for ORR. -- Abstract: Here we present a facile synthetic route to design nitrogen-doped nanostructured carbon-based electrocatalyst for oxygen reduction reaction (ORR) by the copyrolysis of blood biomass from pig and carbon nanotubes (CNTs) at high temperatures. The nitrogen-doped CNTs obtained at 800 °C not only results in excellent ORR activity with four-electron transfer selectivity in alkaline medium, but also exhibits superior methanol-tolerant property and long-term stability. It is confirmed that high-temperature pyrolysis processes can facilitate to produce higher contents of pyridinic- and pyrrolic-N binding groups in electrocatalysts, contributing to the enhancement of ORR performance in terms of onset potential, half-wave potential, and limited current density. We also propose that the planar-N configuration may be the active site that is responsible for the improved ORR electrocatalytic performance. The straight-forward and cheap synthesis of the active and stable electrocatalyst makes it a promising candidate for electrochemical power sources such as fuel cells or metal-air batteries

  20. Determination of low carbon content in uranium

    International Nuclear Information System (INIS)

    Champeix, L.; Chevilliard, H.; Ponty, J.

    1960-01-01

    The method of carbon determination previously used for low carbon steels has been applied to uranium. Carbon contents down to a few tens p.p.m. and probably to a few p.p.m., can be determined with satisfactory precision, sensibility and accuracy. Reprint of a paper published in 'Memoires Scientifiques Rev. Metallurg.', LVI, n. 7, 1959, p. 657-662 [fr

  1. Carbon, chromium and molybdenum contents

    International Nuclear Information System (INIS)

    Sinatora, A; Goldenstein, H.; Mei, P.R.; Albertin, E.; Fuoco, R.; Mariotto, C.L.

    1992-01-01

    This work describes solidification experiments on white cast iron, with 15 and 20% of chromium, 2.3, 3.0 and 3.6 % of carbon and 0.0, 1.5 and 2.5 % of molybdenum in test de samples with 30 mm diameter. Measurements were performed on the austenite and eutectic formation arrests, the number of the eutectic carbide particles relative to the total and the eutectic volumes, and the volume fraction of the primary austenite

  2. Methodological comparison for quantitative analysis of fossil and recently derived carbon in mine soils with high content of aliphatic kerogen

    Czech Academy of Sciences Publication Activity Database

    Vindušková, O.; Sebag, D.; Cailleau, G.; Brus, Jiří; Frouz, J.

    89-90, December (2015), s. 14-22 ISSN 0146-6380 Institutional support: RVO:61389013 Keywords : kerogen * geogenic carbon * soil organic matter Subject RIV: DD - Geochemistry Impact factor: 2.990, year: 2015

  3. Versatile and biomass synthesis of iron-based nanoparticles supported on carbon matrix with high iron content and tunable reactivity

    International Nuclear Information System (INIS)

    Zhang Dongmao; Shi, Sheldon Q.; Pittman, Charles U.; Jiang Dongping; Che Wen; Gai Zheng; Howe, Jane Y.; More, Karren L.; Antonyraj, Arockiasamy

    2012-01-01

    Iron-based nanoparticles supported on carbon (FeNPs-C) have enormous potential for environmental applications. Reported is a biomass-based method for FeNP-C synthesis that involves pyrolysis of bleached wood fiber pre-mixed with Fe 3 O 4 nanoparticles. This method allows synthesis of iron-based nanoparticles with tunable chemical reactivity by changing the pyrolysis temperature. The FeNP-C synthesized at a pyrolysis temperature of 500 °C (FeNP-C-500) reacts violently (pyrophoric) when exposed to air, while FeNP-C prepared at 800 °C (FeNP-C-800) remains stable in ambient condition for at least 3 months. The FeNPs in FeNP-C-800 are mostly below 50 nm in diameter and are surrounded by carbon. The immediate carbon layer (within 5–15 nm radius) on the FeNPs is graphitized. Proof-of-concept environmental applications of FeNPs-C-800 were demonstrated by Rhodamine 6G and arsenate (V) removal from water. This biomass-based method provides an effective way for iron-based nanoparticle fabrication and biomass utilization.

  4. Validity of estimating the organic carbon content of basin sediment using color measurements

    International Nuclear Information System (INIS)

    Sasaki, Toshinori; Sugai, Toshihiko; Ogami, Takashi; Yanagida, Makoto; Yasue, Ken-ichi

    2010-01-01

    Psychometric lightness (L* value) measured by a colorimeter offers a rapid means of obtaining the organic carbon content of sediment. We measured peat and lacustrine sediments covering the past 300 ka - 106 samples for L* value and 197 samples for organic carbon content. L* values are highly correlated with organic carbon contents. Therefore, L* values are a convenient alternative to measuring organic carbon contents. (author)

  5. Highly stretchable carbon aerogels.

    Science.gov (United States)

    Guo, Fan; Jiang, Yanqiu; Xu, Zhen; Xiao, Youhua; Fang, Bo; Liu, Yingjun; Gao, Weiwei; Zhao, Pei; Wang, Hongtao; Gao, Chao

    2018-02-28

    Carbon aerogels demonstrate wide applications for their ultralow density, rich porosity, and multifunctionalities. Their compressive elasticity has been achieved by different carbons. However, reversibly high stretchability of neat carbon aerogels is still a great challenge owing to their extremely dilute brittle interconnections and poorly ductile cells. Here we report highly stretchable neat carbon aerogels with a retractable 200% elongation through hierarchical synergistic assembly. The hierarchical buckled structures and synergistic reinforcement between graphene and carbon nanotubes enable a temperature-invariable, recoverable stretching elasticity with small energy dissipation (~0.1, 100% strain) and high fatigue resistance more than 10 6 cycles. The ultralight carbon aerogels with both stretchability and compressibility were designed as strain sensors for logic identification of sophisticated shape conversions. Our methodology paves the way to highly stretchable carbon and neat inorganic materials with extensive applications in aerospace, smart robots, and wearable devices.

  6. The use of coal-tar pitches of very high softening point and low carcinogen content as binders for industrial carbon

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    It has been demonstrated that the content of known carcinogenic polynuclear aromatic hydrocarbons (PAH) in coal-tar pitches may be reduced to levels which comply with existing and/or proposed environmental legislation, typically by distillation at low pressures, and preferably using a form of thin-film evaporation apparatus. However, the immediate products of such distillations usually have very high softening points, typically above 200{degree}C, and are unsuitable for direct utilization in conventional commercial carbon manufacturing processes as a result of the need for very high mixing temperatures. Advantage has been taken of the of a low-PAH coal-tar pitch, supplied in powder form, which has a softening point above 200{degree}C. Methods were examined which might allow mixing and forming of the hard pitch and a petroleum coke aggregate blend either at room temperature or at conventional processing temperature, and hot-pressuring or sintering procedures in which mixtures of the hard pitch and petroleum coke aggregate were formed at or above the softening temperature of the pitch. All the formed products were baked to give carbons which were evaluated for the major properties of density, electrical resistivity and strength. A comparison was also made between the volatiles evolved during the baking of products made with the low-PAH pitch and those made with a conventional coal-tar binder pitch.

  7. Limitations of using Raman microscopy for the analysis of high-content-carbon-filled ethylene propylene diene monomer rubber

    DEFF Research Database (Denmark)

    Ghanbari-Siahkali, A.; Almdal, K.; Kingshott, P.

    2003-01-01

    The effects of laser irradiation on changes to the surface chemistry and structure of a commercially available ethylene propylene diene monomer (EPDM) rubber sample after Raman microscopy analysis was investigated. The Raman measurements were carried out with different levels of laser power...... on the sample, ranging from 4.55 mW to 0.09 mW. The surface of the EPDM was analyzed before and after laser exposure using X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The techniques have surface probe depths of approximately less...... than or equal to10 nm and 1 mum, respectively. Both sets of analysis show that ingredients of the blended EPDM rubber "bloom" to the surface as a result of local heating that takes place due to the absorption of laser by carbon black during the Raman analysis. Scanning electron microscopy (SEM...

  8. Determination of free carbon content in boron carbide ceramic powders

    International Nuclear Information System (INIS)

    Castro, A.R.M. de; Lima, N.B. de; Paschoal, J.O.A.

    1990-01-01

    Boron carbide is a ceramic material of technological importance due to its hardness and high chemical and thermal stabilities. Free carbon is always found as a process dependent impurity in boron carbide. The development of procedures for its detection is required because its presence leads to a degradation of the boron carbide properties. In this work, several procedures for determining free carbon content in boron carbide specimens are reported and discussed for comparison purposes. (author) [pt

  9. Characterization of sp3 bond content of carbon films deposited by high power gas injection magnetron sputtering method by UV and VIS Raman spectroscopy

    Science.gov (United States)

    Zdunek, Krzysztof; Chodun, Rafał; Wicher, Bartosz; Nowakowska-Langier, Katarzyna; Okrasa, Sebastian

    2018-04-01

    This paper presents the results of investigations of carbon films deposited by a modified version of the magnetron sputtering method - HiPGIMS (High Power Gas Injection Magnetron Sputtering). In this experiment, the magnetron system with inversely polarized electrodes (sputtered cathode at ground potential and positively biased, spatially separated anode) was used. This arrangement allowed us to conduct the experiment using voltages ranging from 1 to 2 kV and a power supply system equipped with 25/50 μF capacitor battery. Carbon films were investigated by VIS/UV Raman spectroscopy. Sp3/sp2 bonding ratio was evaluated basing the elementary components of registered spectra. Our investigation showed that sp3 bond content increases with discharge power but up to specific value only. In extreme conditions of generating plasma impulses, we detected a reversed relation of the sp3/sp2 ratio. In our opinion, a energy of plasma pulse favors nucleation of a sp3 phase because of a relatively higher ionization state but in extreme cases the influence of energy is reversed.

  10. Characterization of sp3 bond content of carbon films deposited by high power gas injection magnetron sputtering method by UV and VIS Raman spectroscopy.

    Science.gov (United States)

    Zdunek, Krzysztof; Chodun, Rafał; Wicher, Bartosz; Nowakowska-Langier, Katarzyna; Okrasa, Sebastian

    2018-04-05

    This paper presents the results of investigations of carbon films deposited by a modified version of the magnetron sputtering method - HiPGIMS (High Power Gas Injection Magnetron Sputtering). In this experiment, the magnetron system with inversely polarized electrodes (sputtered cathode at ground potential and positively biased, spatially separated anode) was used. This arrangement allowed us to conduct the experiment using voltages ranging from 1 to 2kV and a power supply system equipped with 25/50μF capacitor battery. Carbon films were investigated by VIS/UV Raman spectroscopy. Sp 3 /sp 2 bonding ratio was evaluated basing the elementary components of registered spectra. Our investigation showed that sp 3 bond content increases with discharge power but up to specific value only. In extreme conditions of generating plasma impulses, we detected a reversed relation of the sp 3 /sp 2 ratio. In our opinion, a energy of plasma pulse favors nucleation of a sp 3 phase because of a relatively higher ionization state but in extreme cases the influence of energy is reversed. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Content of nitrogen in waste petroleum carbon for steel industries

    International Nuclear Information System (INIS)

    Rios, R.O; Jimenez, A.F; Szieber, C.W; Banchik, A.D

    2004-01-01

    Steel industries use refined carbon as an alloy for steel production. This alloy is produced from waste carbon from the distillation of the petroleum. The refined carbon, called recarburizer, is obtained by calcination at high temperature. Under these thermal conditions the organic molecules decompose and a fraction of the N 2 , S and H 2 , volatile material and moisture are released; while the carbon tends to develop a crystalline structure similar to graphite's. The right combination of calcinations temperature and time in the furnace can optimize the quality of the resulting product. The content of S and N 2 has to be minimized for the use of calcined carbon in the steel industry. Nitrogen content should be reduced by two orders of magnitude, from 1% - 2% down to hundreds of ppm by weight. This work describes the activities undertaken to obtain calcined coke from petroleum from crude oil carbon that satisfies the requirements of the Mercosur standard 02:00-169 (Pending) for use as a carborizer in steels industries. To satisfy the requirements of the Mercosur standards NM 236:00 IRAM-IAS-NM so that graphite is used as a carburizer a content of 300 ppm maximum weight of nitrogen has to be obtained. So the first stage in this development is to define a production process for supplying calcined coke in the range of nitrogen concentrations required by the Mercosur standards (CW)

  12. Determination of contents of carbonate and hydrogen carbonate in solutions for alkaline leading of uranium ores

    International Nuclear Information System (INIS)

    Radil, V.

    1988-01-01

    The new analytical method is based on the determination of the molar ratio carbonate - hydrogen carbonate using the measured concentration of hydrogen ions, the determination of the dissociation constant of carbonic acid for different values of ionic strength. The concentration of hydrogen ions was measured with a Metrohm 632 pH meter with the use of a combined glass electrode. The content of total carbonate carbon was determined coulometrically and the uranium content was determined by extraction with tributyl phosphate and by spectrometry of the complex of uranyl ions with Arsenazo III. Model solutions were used for the experiments which contained a high concentration of sulfate ions, thiosulfate ions, uranium and various proportions of carbonate and hydrogen carbonate. The composition of the individual samples of the extraction solutions are tabulated. The calibration was made of the glass combined electrode at different ionic strength, the values determined of dissociation constants of carbonic acid for different ionic strength. The mathematical procedure is described for the calculation of molar concentrations of carbonate and hudrogen carbonate and the results are presented of the analysis of model solutions. (E.S.). 5 tabs., 1 fig., 5 refs

  13. Biodiesel production from Silybum marianum L. seed oil with high FFA content using sulfonated carbon catalyst for esterification and base catalyst for transesterification

    International Nuclear Information System (INIS)

    Fadhil, Abdelrahman B.; Aziz, Akram M.; Al-Tamer, Marwa H.

    2016-01-01

    Highlights: • PET was converted to activated carbon and then sulfonated to prepare carbon acid catalyst. • Carbon acid catalyst was used for esterification of high acid value Silybum marianum L. seed oil. • Biodiesel was obtained with 96.98% efficiency. - Abstract: In this research work, waste of polyethylene terephthalate (PET) was converted into activated carbon and the latter was used in the preparation of a carbon acid catalyst. Waste of PET was converted into activated carbon via carbonization and steam activation, then the activated carbon was sulfonated using fuming sulfuric acid in order to produce the carbon acid catalyst. The prepared carbon acid catalyst was tested for esterification of high acid value non-edible oil, Silybum marianum L. seed oil (SMSO) via optimized protocol. Amount of the carbon acid catalyst, methanol to oil molar ratio, temperature and time were the experimental variables optimized. Esterification of SMSO with methanol using the prepared carbon acid catalyst reduced its parent acid value (20.0 mg KOH/g) to the acceptable limits for base-catalyzed transesterification (<2.0 mg KOH/g) using 6.0% w/w of the catalyst, 15:1 methanol to oil molar ratio, 68 °C reaction temperature and 180 min of reaction. The performance of the catalyst was reduced gradually during its recycling and reached to 60.0% at the 5th cycle. Kinetics of esterification of SMSO using the prepared carbon acid catalyst followed pseudo first order kinetics, and the activation energy was found to be 70.98 kJ/mol. The esterified oil was converted to biodiesel through optimized base-catalyzed transesterification with methanol. Biodiesel with (96.98% yield and purity of 96.69% w/w) yield was obtained using 0.80% KOH w/w, 6:1 methanol to oil molar ratio, 60 °C reaction temperature, 75 min of reaction and 600 rpm rate of stirring. The biodiesel properties were within the recommended biodiesel standards as prescribed by ASTM D 6751 and EN 14214. Transesterification of

  14. The Effects of Earth Science Textbook Contents on High School Students' Knowledge of, Attitude toward, and Behavior of Energy Saving and Carbon Reduction

    Science.gov (United States)

    Chao, Yu-Long; Chou, Ying-Chyi; Yen, Hsin-Yi; Chen, Shr-Jya

    2017-01-01

    As science textbooks are considered as one of the major source of climate change information of students, this study aims to examine the differences in energy saving and carbon reduction knowledge, attitude, and behavior between two groups of Taiwan's high school students using earth science textbooks of two different publishers. Some items of…

  15. Estimation of cerium and lanthanum content in core material of high intensity carbon arc electrodes by x-ray fluorescence method

    International Nuclear Information System (INIS)

    Nagpal, K.C.; Bhavalkar, R.H.

    1977-01-01

    The X-ray fluorescence method has been used to determine the weight percentages of cerium and lanthanum in the core material of high intensity carbon arc electrodes from the calibration curves plotted between the weight percentages of these elements and the peak-intensity ratios of CeLsub(α1), and LaLsub(α1) peaks to the neighbouring peak SnLsub(α1) due to an internal standard element. (author)

  16. Interfaces between Model Co-W-C Alloys with Various Carbon Contents and Tungsten Carbide

    Directory of Open Access Journals (Sweden)

    Igor Konyashin

    2018-03-01

    Full Text Available Interfaces between alloys simulating binders in WC-Co cemented carbides and tungsten carbide were examined on the micro-, nano-, and atomic-scale. The precipitation of fine WC grains and η-phase occurs at the interface of the alloy with the low carbon content. The precipitation of such grains almost does not occur in the alloy with the medium-low carbon content and does not take place in the alloy with the high carbon content. The formation of Co nanoparticles in the binder alloy with the medium-low carbon content was established. Interfaces in the alloy with the medium-low carbon content characterized by complete wetting with respect to WC and with the high carbon content characterized by incomplete wetting were examined at an atomic scale. The absence of any additional phases or carbon segregations at both of the interfaces was established. Thus, the phenomenon of incomplete wetting of WC by liquid binders with high carbon contents is presumably related to special features of the Co-based binder alloys oversaturated with carbon at sintering temperatures.

  17. Modelling and mapping the topsoil organic carbon content for Tanzania

    Science.gov (United States)

    Kempen, Bas; Kaaya, Abel; Ngonyani Mhaiki, Consolatha; Kiluvia, Shani; Ruiperez-Gonzalez, Maria; Batjes, Niels; Dalsgaard, Soren

    2014-05-01

    Soil organic carbon (SOC), held in soil organic matter, is a key indicator of soil health and plays an important role in the global carbon cycle. The soil can act as a net source or sink of carbon depending on land use and management. Deforestation and forest degradation lead to the release of vast amounts of carbon from the soil in the form of greenhouse gasses, especially in tropical countries. Tanzania has a high deforestation rate: it is estimated that the country loses 1.1% of its total forested area annually. During 2010-2013 Tanzania has been a pilot country under the UN-REDD programme. This programme has supported Tanzania in its initial efforts towards reducing greenhouse gas emission from forest degradation and deforestation and towards preserving soil carbon stocks. Formulation and implementation of the national REDD strategy requires detailed information on the five carbon pools among these the SOC pool. The spatial distribution of SOC contents and stocks was not available for Tanzania. The initial aim of this research, was therefore to develop high-resolution maps of the SOC content for the country. The mapping exercise was carried out in a collaborative effort with four Tanzanian institutes and data from the Africa Soil Information Service initiative (AfSIS). The mapping exercise was provided with over 3200 field observations on SOC from four sources; this is the most comprehensive soil dataset collected in Tanzania so far. The main source of soil samples was the National Forest Monitoring and Assessment (NAFORMA). The carbon maps were generated by means of digital soil mapping using regression-kriging. Maps at 250 m spatial resolution were developed for four depth layers: 0-10 cm, 10-20 cm, 20-30 cm, and 0-30 cm. A total of 37 environmental GIS data layers were prepared for use as covariates in the regression model. These included vegetation indices, terrain parameters, surface temperature, spectral reflectances, a land cover map and a small

  18. High capacity carbon dioxide sorbent

    Science.gov (United States)

    Dietz, Steven Dean; Alptekin, Gokhan; Jayaraman, Ambalavanan

    2015-09-01

    The present invention provides a sorbent for the removal of carbon dioxide from gas streams, comprising: a CO.sub.2 capacity of at least 9 weight percent when measured at 22.degree. C. and 1 atmosphere; an H.sub.2O capacity of at most 15 weight percent when measured at 25.degree. C. and 1 atmosphere; and an isosteric heat of adsorption of from 5 to 8.5 kilocalories per mole of CO.sub.2. The invention also provides a carbon sorbent in a powder, a granular or a pellet form for the removal of carbon dioxide from gas streams, comprising: a carbon content of at least 90 weight percent; a nitrogen content of at least 1 weight percent; an oxygen content of at most 3 weight percent; a BET surface area from 50 to 2600 m.sup.2/g; and a DFT micropore volume from 0.04 to 0.8 cc/g.

  19. Extraction efficiency of water, ethanol and supereritical carbon dioxide for amide content from fruit of piper sarmentosum using colorimetry and high performance liquid chromatography

    International Nuclear Information System (INIS)

    Hussain, K.; Ismail, Z.; Ibrahim, P.

    2010-01-01

    Extraction is important for both natural product research and preparation of extracts to be used as raw materials for phytopharamaceuticals. Selection of a suitable solvent as well as type of extraction is prerequisite to prepare extracts enriched with particular type of compounds with peculiar activities. Therefore, the present study aimed to evaluate the extraction efficiency of water, ethanol and supercritical CO/sub 2/ for amides from fruit of Piper sarmentosum using colorimetry and high performance liquid chromatography (HPLC). The pulverized fruit material was extracted by reflux using water and ethanol, and supercritical CO/sub 2/ at 60 degree c and operating pressure of 3000,4 000, 6000, 7000 and 8000 psi. The colorimetric analysis indicated that except the water extracts, total amide content in different extracts was not significantly different (P<0.05). Similarly, HPLC analysis using pellitorine, sarmentine and sarrnentosine as markers indicated that except water extracts, total content of the markers in different extracts was not significantly different (P<0.05). These results indicate that extraction efficiency of ethanol for amides is comparable to that of supercritical CO/sub 2/. Hence, ethanol may be used to prepare amide enriched extracts without using costly equipment and operating expertise. (author)

  20. Organic carbon, nitrogen and phosphorus contents of some tea soils

    International Nuclear Information System (INIS)

    Ahmed, M.S.; Zamir, M.R.; Sanauallah, A.F.M.

    2005-01-01

    Soil samples were collected from Rungicherra Tea-Estate of Moulvibazar district, Bangladesh. Organic carbon, organic matter, total nitrogen and available phosphorus content of the collected soil of different topographic positions have been determined. The experimental data have been analyzed statistically and plotted against topography and soil depth. Organic carbon and organic matter content varied from 0.79 to 1.24% and 1.37 to 2.14%. respectively. Total nitrogen and available phosphorus content of these soils varied respectively from 0.095 to 0.13% and 2.31 to 4.02 ppm. (author)

  1. Effects of carbon nanotube content and annealing temperature on the hardness of CNT reinforced aluminum nanocomposites processed by the high pressure torsion technique

    Energy Technology Data Exchange (ETDEWEB)

    Phuong, Doan Dinh, E-mail: phuongdd@ims.vast.ac.vn [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Str., Cau Giay Distr., Hanoi (Viet Nam); Trinh, Pham Van; An, Nguyen Van; Luan, Nguyen Van; Minh, Phan Ngoc [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Str., Cau Giay Distr., Hanoi (Viet Nam); Khisamov, Rinat Kh.; Nazarov, Konstantin S.; Zubairov, Linar R.; Mulyukov, Radik R.; Nazarov, Ayrat A. [Institute for Metals Superplasticity Problems, Russian Academy of Sciences 39, Stepan Khalturin Str., Ufa 450001 (Russian Federation)

    2014-11-15

    Highlights: • CNT/Al nanocomposites were consolidated by HIP and subsequently processed by the high pressure torsion technique. • High pressure torsion processing was unable to break apart or disperse the CNT agglomerates persisted in powder preparation. • HPT-processed CNT/Al nanocomposites exhibited secondary hardening during annealing at temperatures below 150 °C. - Abstract: In this paper, the microstructure and hardness of CNT reinforced aluminium (CNT/Al) nanocomposites prepared by the advanced powder metallurgy method and subsequently processed by the high pressure torsion (HPT) technique are studied. The effects of CNT content and annealing temperature on the hardness of the nanocomposites are investigated. The results show that annealing materials at temperatures below 150 °C leads to secondary hardening, while annealing at higher temperatures soften the nanocomposites. HPT-processed CNT/Al nanocomposites with 1.5 wt.% of CNTs are shown to have the highest hardness in comparison with other composites containing CNTs from 0 up to 2 wt.%. Microstructures, CNT distribution and the phase composition of CNT/Al nanocomposites are investigated by transmission and scanning electron microscopy and X-ray diffraction techniques.

  2. Determination of carbon content of UO2, (U, Gd)O2 and (U, Pu)O2 powders and sintered pellets - Combustion in a high-frequency induction furnace -Infrared absorption spectrometry

    International Nuclear Information System (INIS)

    2008-01-01

    This International Standard describes a method for determining the carbon content in UO 2 , (U,Gd)O 2 and (U,Pu)O 2 powder and sintered pellets by combustion in an induction furnace and infrared absorption spectroscopy measurement. It is applicable for determining 10 μg/g to 500 μg/g of carbon in UO 2 , (U,Gd)O 2 and (U,Pu)O 2 powder and pellets. The sample is heated to a temperature above 1500 deg. C in an induction furnace, under pure oxygen atmosphere, to convert any carbon compounds to carbon dioxide gas. The resulting carbon dioxide gas is filtered and dried before measurement using infrared spectroscopy to measure the carbon dioxide signal at 2350 cm -1 . The result is converted into the carbon content of the material analysed

  3. Investigate of analysis for hydrogen contents in carbon films

    International Nuclear Information System (INIS)

    Yasui, Haruyuki; Hirose, Yukio; Sasaki, Toshihiko; Awazu, Kaoru; Naramoto, Hiroshi

    2001-01-01

    Hydrogen is a very common contaminant in carbon films. It can strongly influences on mechanical, physical and chemical properties of the films. The analysis of hydrogen is therefore a crucial problem to prepare the films with the reproducible property. We were measured two kinds of methods. Ion beam techniques using nuclear reactions are established methods for the quantitative determination of hydrogen concentration. A spectrometer has been constructed for the determination of hydrogen concentrations by detecting 4.43 MeV γ-rays from the resonant nuclear reactions 1 H( 15 N, α γ) 12 C at the 6.385 MeV. And the other measurement of hydrogen is GDOES (Glow Discharge Optical Emission Spectroscopy), with its high sputtering rates, had been used previously for depth profiling analysis of thin films. The depth profiling analysis was carried out at an argon atmosphere by applying an RF of 13.56 MHz. The sampling time interval was 0.1 sec. The detailed hydrogen analysis was made on BCN (Boron Carbonitride) and DLC (Diamond-like Carbon) thin films. The BCN films were prepared by ion beam assisted deposition, in which boron and carbon were deposited by electron beam heating of B 4 C solid and nitrogen was supplied by implantation simultaneously. The DLC films were prepared by HPPC (Hybrid-pulse plasma coating) system. It was a new coating system that we developed which consists fundamentally of plasma CVD (chemical vapor deposition) and ion-mixing. In this paper, we reported the comparison of analysis for hydrogen contents between RNRA and GDOES. (author)

  4. Investigate of analysis for hydrogen contents in carbon films

    Energy Technology Data Exchange (ETDEWEB)

    Yasui, Haruyuki; Hirose, Yukio; Sasaki, Toshihiko [Kanazawa Univ., Kanazawa, Ishikawa (Japan); Awazu, Kaoru [Industrial Research Institute of Ishikawa, Kanazawa, Ishikawa (Japan); Naramoto, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2001-07-01

    Hydrogen is a very common contaminant in carbon films. It can strongly influences on mechanical, physical and chemical properties of the films. The analysis of hydrogen is therefore a crucial problem to prepare the films with the reproducible property. We were measured two kinds of methods. Ion beam techniques using nuclear reactions are established methods for the quantitative determination of hydrogen concentration. A spectrometer has been constructed for the determination of hydrogen concentrations by detecting 4.43 MeV {gamma}-rays from the resonant nuclear reactions {sup 1}H({sup 15}N, {alpha} {gamma}){sup 12}C at the 6.385 MeV. And the other measurement of hydrogen is GDOES (Glow Discharge Optical Emission Spectroscopy), with its high sputtering rates, had been used previously for depth profiling analysis of thin films. The depth profiling analysis was carried out at an argon atmosphere by applying an RF of 13.56 MHz. The sampling time interval was 0.1 sec. The detailed hydrogen analysis was made on BCN (Boron Carbonitride) and DLC (Diamond-like Carbon) thin films. The BCN films were prepared by ion beam assisted deposition, in which boron and carbon were deposited by electron beam heating of B{sub 4}C solid and nitrogen was supplied by implantation simultaneously. The DLC films were prepared by HPPC (Hybrid-pulse plasma coating) system. It was a new coating system that we developed which consists fundamentally of plasma CVD (chemical vapor deposition) and ion-mixing. In this paper, we reported the comparison of analysis for hydrogen contents between RNRA and GDOES. (author)

  5. Stable isotope compositions of organic carbon and contents of ...

    African Journals Online (AJOL)

    The stable isotope compositions of organic carbon (OC), and contents of OC and nitrogen for four sediment cores recovered from lakes Makat (located in the Ngorongoro Crater), Ndutu and Masek (located in the Serengeti Plains) are used to document sources of organic matter (OM) and climatic changes in sub-arid ...

  6. Properties of welded joints of 2,25Cr-1Mo steel with various carbon content

    International Nuclear Information System (INIS)

    Vornovitskij, I.N.; Brodetskaya, E.Z.; Pozdnyakova, A.S.

    1980-01-01

    Properties of welded joints of 2,25 Cr - 1 Mo steel pipelines with different carbon content are considered. It is shown that application of electrodes developed in some countries for welding permits in many cases to exclude heat treatment of welded joints owing to high ductility of weld deposited metal. To improve the ductility, it is necessary to limit both carbon content down to 0,03-0,06% and detrimental elements (sulfur, phosphorus). Heat affected zone hardness may be increased at the expense of carbon. Weld deposited metal possesses the highest long-term strength at the given test temperature; in this case long-term strength of welded joints and base metal is practically the same. The long-term strength of high-carbon steel is higher at the test temperature of 565 deg C as compared to mean-carbon and low-carbon steels, whose long-term strength is practically equal at this temperature. The long-term strength of high-carbon and mean-carbon steels is practically the same and higher as compared with low-carbon one at the test temperature of 510 deg C

  7. Inferring absorbing organic carbon content from AERONET data

    Directory of Open Access Journals (Sweden)

    A. Arola

    2011-01-01

    Full Text Available Black carbon, light-absorbing organic carbon (often called "brown carbon" and mineral dust are the major light-absorbing aerosols. Currently the sources and formation of brown carbon aerosol in particular are not well understood. In this study we estimated the amount of light–absorbing organic carbon and black carbon from AERONET measurements. We find that the columnar absorbing organic carbon (brown carbon levels in biomass burning regions of South America and Africa are relatively high (about 15–20 mg m−2 during biomass burning season, while the concentrations are significantly lower in urban areas in US and Europe. However, we estimated significant absorbing organic carbon amounts from the data of megacities of newly industrialized countries, particularly in India and China, showing also clear seasonality with peak values up to 30–35 mg m−2 during the coldest season, likely caused by the coal and biofuel burning used for heating. We also compared our retrievals with the modeled organic carbon by the global Oslo CTM for several sites. Model values are higher in biomass burning regions than AERONET-based retrievals, while the opposite is true in urban areas in India and China.

  8. Inferring absorbing organic carbon content from AERONET data

    Science.gov (United States)

    Arola, A.; Schuster, G.; Myhre, G.; Kazadzis, S.; Dey, S.; Tripathi, S. N.

    2011-01-01

    Black carbon, light-absorbing organic carbon (often called "brown carbon") and mineral dust are the major light-absorbing aerosols. Currently the sources and formation of brown carbon aerosol in particular are not well understood. In this study we estimated the amount of light-absorbing organic carbon and black carbon from AERONET measurements. We find that the columnar absorbing organic carbon (brown carbon) levels in biomass burning regions of South America and Africa are relatively high (about 15-20 mg m-2 during biomass burning season), while the concentrations are significantly lower in urban areas in US and Europe. However, we estimated significant absorbing organic carbon amounts from the data of megacities of newly industrialized countries, particularly in India and China, showing also clear seasonality with peak values up to 30-35 mg m-2 during the coldest season, likely caused by the coal and biofuel burning used for heating. We also compared our retrievals with the modeled organic carbon by the global Oslo CTM for several sites. Model values are higher in biomass burning regions than AERONET-based retrievals, while the opposite is true in urban areas in India and China.

  9. Estimation of black carbon content for biomass burning aerosols from multi-channel Raman lidar data

    Science.gov (United States)

    Talianu, Camelia; Marmureanu, Luminita; Nicolae, Doina

    2015-04-01

    Biomass burning due to natural processes (forest fires) or anthropical activities (agriculture, thermal power stations, domestic heating) is an important source of aerosols with a high content of carbon components (black carbon and organic carbon). Multi-channel Raman lidars provide information on the spectral dependence of the backscatter and extinction coefficients, embedding information on the black carbon content. Aerosols with a high content of black carbon have large extinction coefficients and small backscatter coefficients (strong absorption), while aerosols with high content of organic carbon have large backscatter coefficients (weak absorption). This paper presents a method based on radiative calculations to estimate the black carbon content of biomass burning aerosols from 3b+2a+1d lidar signals. Data is collected at Magurele, Romania, at the cross-road of air masses coming from Ukraine, Russia and Greece, where burning events are frequent during both cold and hot seasons. Aerosols are transported in the free troposphere, generally in the 2-4 km altitude range, and reaches the lidar location after 2-3 days. Optical data are collected between 2011-2012 by a multi-channel Raman lidar and follows the quality assurance program of EARLINET. Radiative calculations are made with libRadTran, an open source radiative model developed by ESA. Validation of the retrievals is made by comparison to a co-located C-ToF Aerosol Mass Spectrometer. Keywords: Lidar, aerosols, biomass burning, radiative model, black carbon Acknowledgment: This work has been supported by grants of the Romanian National Authority for Scientific Research, Programme for Research- Space Technology and Advanced Research - STAR, project no. 39/2012 - SIAFIM, and by Romanian Partnerships in priority areas PNII implemented with MEN-UEFISCDI support, project no. 309/2014 - MOBBE

  10. Blue carbon content of mangrove vegetation in Subang district

    Science.gov (United States)

    Nurruhwati, I.; Purwita, S. D.; Sunarto; Zahidah

    2018-04-01

    The purpose of this research was to know the carbon content of mangrove parts such as leave, stems and roots and to know its ability to absorb carbondioxide (CO2). The research was conducted in 27th April until 16th May 2017 in Blanakan Village, Langensari Village and Jayamukti Village. The samples are dried at Pilotplane Laboratory Faculty of Industrial Engineering Padjadjaran University. The method in this research is explorative survey method. The results showed that there were two dominant mangroves species in three research stations, they are Avicennia marina and Rhizophora mucronata. Index of Important value of each mangrove type on the three stations in the medium criterion with a range of values is 106,86 %- 193,13 %. The highest carbon content was found in Rhizophora mucronata at station 1 (93,43 %) which was equivalent with 342,87 % absorption of CO2 which was The lowest carbon content was in Avicennia marina at station 1 (67,49 %) which was equivalent with 247,70 % absorption of CO2.

  11. Argon laser induced changes to the carbonate content of enamel

    International Nuclear Information System (INIS)

    Ziglo, M.J.; Nelson, A.E.; Heo, G.; Major, P.W.

    2009-01-01

    Argon laser irradiation can be used to cure orthodontic brackets onto teeth in significantly less time than conventional curing lights. In addition, it has been shown that the argon laser seems to impart a demineralization resistance to the enamel. The purpose of this study was to use surface science techniques to ascertain if this demineralization resistance is possibly a result of a decrease in the carbonate content of enamel. Eleven mandibular third molars previously scheduled for extraction were collected and used in the present study. The teeth were sectioned in two and randomly assigned to either the argon laser (457-502 nm; 250 mW cm -2 ) or the control (no treatment) group. The sections assigned to the argon laser group were cured for 10 s and analyzed. To exaggerate any potential changes the experimental sections were then exposed to a further 110 s of argon laser irradiation. Surface analysis was performed using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The results showed no statistically significant change in the carbonate content of enamel after argon laser irradiation (p > 0.05). Thus, it is suggested that any demineralization resistance imparted to the enamel surface by argon laser irradiation is not due to alterations in carbonate content.

  12. Argon laser induced changes to the carbonate content of enamel

    Energy Technology Data Exchange (ETDEWEB)

    Ziglo, M.J. [Orthodontic Graduate Program, Faculty of Medicine and Dentistry, University of Alberta, Private Practice, Regina, Saskatchewan (Canada); Nelson, A.E., E-mail: aenelson@dow.com [Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta (Canada); Heo, G.; Major, P.W. [Orthodontic Graduate Program, Faculty of Medicine and Dentistry, University of Alberta (Canada)

    2009-05-15

    Argon laser irradiation can be used to cure orthodontic brackets onto teeth in significantly less time than conventional curing lights. In addition, it has been shown that the argon laser seems to impart a demineralization resistance to the enamel. The purpose of this study was to use surface science techniques to ascertain if this demineralization resistance is possibly a result of a decrease in the carbonate content of enamel. Eleven mandibular third molars previously scheduled for extraction were collected and used in the present study. The teeth were sectioned in two and randomly assigned to either the argon laser (457-502 nm; 250 mW cm{sup -2}) or the control (no treatment) group. The sections assigned to the argon laser group were cured for 10 s and analyzed. To exaggerate any potential changes the experimental sections were then exposed to a further 110 s of argon laser irradiation. Surface analysis was performed using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The results showed no statistically significant change in the carbonate content of enamel after argon laser irradiation (p > 0.05). Thus, it is suggested that any demineralization resistance imparted to the enamel surface by argon laser irradiation is not due to alterations in carbonate content.

  13. Argon laser induced changes to the carbonate content of enamel

    Science.gov (United States)

    Ziglo, M. J.; Nelson, A. E.; Heo, G.; Major, P. W.

    2009-05-01

    Argon laser irradiation can be used to cure orthodontic brackets onto teeth in significantly less time than conventional curing lights. In addition, it has been shown that the argon laser seems to impart a demineralization resistance to the enamel. The purpose of this study was to use surface science techniques to ascertain if this demineralization resistance is possibly a result of a decrease in the carbonate content of enamel. Eleven mandibular third molars previously scheduled for extraction were collected and used in the present study. The teeth were sectioned in two and randomly assigned to either the argon laser (457-502 nm; 250 mW cm -2) or the control (no treatment) group. The sections assigned to the argon laser group were cured for 10 s and analyzed. To exaggerate any potential changes the experimental sections were then exposed to a further 110 s of argon laser irradiation. Surface analysis was performed using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The results showed no statistically significant change in the carbonate content of enamel after argon laser irradiation ( p > 0.05). Thus, it is suggested that any demineralization resistance imparted to the enamel surface by argon laser irradiation is not due to alterations in carbonate content.

  14. Soil carbon content and relative abundance of high affinity H2-oxidizing bacteria predict atmospheric H2 soil uptake activity better than soil microbial community composition

    NARCIS (Netherlands)

    Khdhiri, Mondher; Hesse, Laura; Popa, Maria Elena; Quiza, Liliana; Lalonde, Isabelle; Meredith, Laura K.; Röckmann, Thomas; Constant, Philippe

    2015-01-01

    Soil-atmosphere exchange of H2 is controlled by gas diffusion and the microbial production and oxidation activities in soil. Among these parameters, the H2 oxidation activity catalyzed by soil microorganisms harboring high affinity hydrogenase is the most difficult variable to parameterize because

  15. Physical and chemical protection of soil organic carbon in three agricultural soils with different contents of calcium carbonate

    International Nuclear Information System (INIS)

    Clough, A.; Skjemstad, J.O.

    2000-01-01

    The amount of organic carbon physically protected by entrapment within aggregates and through polyvalent cation organic matter bridging was determined on non-calcareous and calcareous soils. The composition of organic carbon in whole soils and 13 C NMR analysis. High energy photo-oxidation was carried out on <53 μm fractions and results from the NMR spectra showed 17-40% of organic carbon was in a condensed aromatic form, most likely charcoal (char). The concept that organic material remaining after photo-oxidation may be physically protected within aggregates was investigated by treating soils with a mild acid prior to photo-oxidation. More organic material was protected in the calcareous than the non-calcareous soils, regardless of whether the calcium occurred naturally or was an amendment. Acid treatment indicated that the presence of exchangeable calcium reduced losses of organic material upon photo-oxidation by about 7% due to calcium bridging. These results have implications for N fertiliser recommendations based upon organic carbon content. Firstly, calcium does not impact upon degradability of organic material to an extent likely to affect N fertiliser recommendations. Secondly, standard assessment techniques overestimate active organic carbon content in soils with high char content. Copyright (2000) CSIRO Publishing

  16. Activated carbon oxygen content influence on water and surfactant adsorption.

    Science.gov (United States)

    Pendleton, Phillip; Wu, Sophie Hua; Badalyan, Alexander

    2002-02-15

    This research investigates the adsorption properties of three activated carbons (AC) derived from coconut, coal, and wood origin. Each carbon demonstrates different levels of resistance to 2 M NaOH treatment. The coconut AC offers the greatest and wood AC the least resistance. The influence of base treatment is mapped in terms of its effects on specific surface area, micropore volume, water adsorption, and dodecanoic acid adsorption from both water and 2 M NaOH solution. A linear relationship exists between the number of water molecules adsorbed at the B-point of the water adsorption isotherm and the oxygen content determined from elemental analysis. Surfactant adsorption isotherms from water and 2 M NaOH indicate that the AC oxygen content effects a greater dependence on affinity for surfactant than specific surface area and micropore volume. We show a linear relationship between the plateau amount of surfactant adsorbed and the AC oxygen content in both water and NaOH phases. The higher the AC oxygen content, the lower the amount of surfactant adsorbed. In contrast, no obvious relationship could be drawn between the surfactant amount adsorbed and the surface area.

  17. FP corrosion dependence on carbon and chromium content in Fe-Cr steel

    International Nuclear Information System (INIS)

    Sasaki, Koei; Tanigaki, Takanori; Fukumoto, Ken-ichi; Uno, Masayoshi

    2015-01-01

    In an attempt to investigate Cs or Cs-Te corrosion dependence on chromium or carbon content in Fe-Cr steel, cesium and Cs-Te corrosion test were performed to three specimens, Fe-9Cr-0C, Fe-9Cr-0.14C and Fe-13Cr-0.14C, for 100 hours at 973K in simulated high burn-up fuel pin environment. Cesium corrosion depth has no dependence on chromium or carbon content in Fe-Cr steel. Cs-Te corrosion was appeared in only Fe-13Cr-0.14C which has chromium carbides ranged along grain boundary. Appearance of the Cs-Te corrosion was determined by distribution or arrangement of chromium carbides which depends on chromium and carbon content. (author)

  18. Effect of carbon content on microstructure and mechanical properties of hot-rolled low carbon 12Cr-Ni stainless steel

    International Nuclear Information System (INIS)

    Zheng, H.; Ye, X.N.; Li, J.D.; Jiang, L.Z.; Liu, Z.Y.; Wang, G.D.; Wang, B.S.

    2010-01-01

    Research highlights: → Hot-rolled ultra low carbon martensite is characterized by dislocation cells substructure. → The formation of dislocation cells is attributed to high Ms and low interstitial atoms content. → Hot-rolled ultra low carbon 12Cr-Ni stainless steel has excellent impact toughness. → Delta ferrite deteriorates the impact toughness of hot-rolled 12Cr-Ni stainless steel. - Abstract: 12Cr-Ni stainless steels containing different carbon contents from 0.004 wt.% to 0.034 wt.% were hot-rolled and air-cooled. Their corresponding microstructures were observed with optical microscope and transmission electron microscope, and the Vickers hardness, tensile and impact tests were also carried out. It was found that the martensitic morphology was significantly influenced by carbon content. The as-received ultra low carbon martensite in the steel containing 0.004 wt.% C is characterized by dislocation cells substructure. The formation of dislocation cells is attributed to high martensite finishing point (above 400 deg. C) and low interstitial atoms content. On the other hand, the martensite in the steel containing 0.034 wt.% C consists mainly of typical martensite laths because of low martensite finishing point and high interstitial atoms content which hinder dislocation motion. Furthermore, carbon content has an evident effect on the mechanical properties of 12Cr-Ni steels. The hardness and strength of the as-received steels increase with an increase in carbon content, but their elongation and impact toughness decrease with the carbon content. The steel containing 0.004 wt.% C has excellent impact toughness due to the ultra low carbon content in the martensite composed of dislocation cells.

  19. Carbon and nitrogen in Danish forest soils - Contents and distribution determined by soil order

    DEFF Research Database (Denmark)

    Vejre, Henrik; Callesen, Ingeborg; Vesterdal, Lars

    2003-01-01

    ). The average total organic C and N contents were 12.5 and 0.61 kg m(-2) respectively. There were large differences in total C and N among soil orders. Spodosols had the greatest C content (14.6 kg m(-2)), and Alfisols the least (8.8 kg m(-2)), while the N content was highest in Alfisols (0.75 kg m(-2......)) and least in Spodosols (0.51 kg m(-2)). The main contributor to the high C content in Spodosols is the spodic horizons containing illuvial humus, and thick organic horizons. Carbon and N concentrations decreased with soil depth. Soil clay content was negatively correlated to C content and positively...

  20. Magnetism as indirect tool for carbon content assessment in nickel nanoparticles

    Science.gov (United States)

    Oumellal, Y.; Magnin, Y.; Martínez de Yuso, A.; Aguiar Hualde, J. M.; Amara, H.; Paul-Boncour, V.; Matei Ghimbeu, C.; Malouche, A.; Bichara, C.; Pellenq, R.; Zlotea, C.

    2017-12-01

    We report a combined experimental and theoretical study to ascertain carbon solubility in nickel nanoparticles embedded into a carbon matrix via the one-pot method. This original approach is based on the experimental characterization of the magnetic properties of Ni at room temperature and Monte Carlo simulations used to calculate the magnetization as a function of C content in Ni nanoparticles. Other commonly used experimental methods fail to accurately determine the chemical analysis of these types of nanoparticles. Thus, we could assess the C content within Ni nanoparticles and it decreases from 8 to around 4 at. % with increasing temperature during the synthesis. This behavior could be related to the catalytic transformation of dissolved C in the Ni particles into graphite layers surrounding the particles at high temperature. The proposed approach is original and easy to implement experimentally since only magnetization measurements at room temperature are needed. Moreover, it can be extended to other types of magnetic nanoparticles dissolving carbon.

  1. High dielectric permittivity and improved mechanical and thermal properties of poly(vinylidene fluoride) composites with low carbon nanotube content: effect of composite processing on phase behavior and dielectric properties.

    Science.gov (United States)

    Kumar, G Sudheer; Vishnupriya, D; Chary, K Suresh; Patro, T Umasankar

    2016-09-23

    The composite processing technique and nanofiller concentration and its functionalization significantly alter the properties of polymer nanocomposites. To realize this, multi-walled carbon nanotubes (CNT) were dispersed in a poly(vinylidene fluoride) (PVDF) matrix at carefully selected CNT concentrations by two illustrious methods, such as solution-cast and melt-mixing. Notwithstanding the processing method, CNTs induced predominantly the γ-phase in PVDF, instead of the commonly obtained β-phase upon nanofiller incorporation, and imparted significant improvements in dielectric properties. Acid-treatment of CNT improved its dispersion and interfacial adhesion significantly with PVDF, and induced a higher γ-phase content and better dielectric properties in PVDF as compared to pristine CNT. Further, the γ-phase content was found to be higher in solution-cast composites than that in melt-mixed counterparts, most likely due to solvent-induced crystallization in a controlled environment and slow solvent evaporation in the former case. However, interestingly, the melt-mixed composites showed a significantly higher dielectric constant at the onset of the CNT networked-structure as compared to the solution-cast composites. This suggests the possible role of CNT breakage during melt-mixing, which might lead to higher space-charge polarization at the polymer-CNT interface, and in turn an increased number of pseudo-microcapacitors in these composites than the solution-cast counterparts. Notably, PVDF with 0.13 vol% (volume fraction, f c  = 0.0013) of acid-treated CNTs, prepared by melt-mixing, displayed the relative permittivity of ∼217 and capacitance of ∼5430 pF, loss tangent of ∼0.4 at 1 kHz and an unprecedented figure of merit of ∼10(5). We suggest a simple hypothesis for the γ-phase formation and evolution of the high dielectric constant in these composites. Further, the high-dielectric composite film showed marked improvements in mechanical and thermal

  2. Fast analysis of carbon content by inelastic scattering of neutrons

    International Nuclear Information System (INIS)

    Heinrich, B.; Irmer, K.; Poetschke, R.

    1986-01-01

    The direct measurement of carbon concentration of conveyor belts is a difficult problem. The great penetration depth by the fast neutrons and the 4.43 MeV γ-radiation gives an especially suitable method. The measurement were performed by the following methods: excitation of γ-radiation by a Pu-Be neutron source, excitation of γ-radiation by DT-neutron generator in stationary regime, in pulse regime, or coupled with time correlated associated particle method. Furthermore, a special Monte Carlo code in which the geometry of the measuring equipment could be specified, was written to calculate the 4.43 MeV γ counting rate for backscatter geometries and for penetration geometries. The influence of conveyor belt, of content of H, O, Fe and of mass by surface for 4.43 MeV γ-radiation was calculated for application brown coal in industry. (author)

  3. Characterization and observation of water-based nanofluids quench medium with carbon particle content variation

    Science.gov (United States)

    Yahya, S. S.; Harjanto, S.; Putra, W. N.; Ramahdita, G.; Kresnodrianto, Mahiswara, E. P.

    2018-05-01

    Recently, nanofluids have been widely used in heat treatment industries as quench medium with better quenching performance. The thermal conductivity of nanofluids is higher compared to conventional quench medium such as polymer, water, brine, and petroleum-based oil. This characteristic can be achieved by mixing high thermal conductivity particles in nanometer scale with a fluid as base. In this research, carbon powder and distilled water were used as nanoparticles and base respectively. The carbon source used in this research was laboratory grade carbon powder, and activated carbon as a cheaper alternative source. By adjusting the percentage of dispersed carbon particles, thermal conductivity of nanofluids could be controlled as needed. To obtain nanoscale carbon particles, planetary ball mill was used to grind laboratory-grade carbon and active carbon powder to further decrease its particle size. This milling method will provide nanoparticles with lower production cost. Milling speed and duration were set at 500 rpm and 15 hours. Scanning electron microscope (SEM) and Energy Dispersive X-Ray (EDX) were carried out respectively to determine the particle size, material identification, particle morphology. The carbon nanoparticle content in nanofluids quench mediums for this research were varied at 0.1, 0.3, and 0.5 % vol. Furthermore, these mediums were used to quench AISI 1045 carbon steel samples which had been annealed at 1000 °C. Hardness testing and metallography observation were then conducted to check the effect of different quench medium in steel samples. Preliminary characterizations showed that the carbon particle dimension after milling was hundreds of nanometers, or still in sub-micron range. Therefore, the milling process parameters are need to be optimized further. EDX observation in laboratory-grade carbon powder showed that the powder was pure carbon as expected for, but in activated carbon has some impurities. The nanofluid itself, however, was

  4. High Content Screening: Understanding Cellular Pathway

    International Nuclear Information System (INIS)

    Mohamed Zaffar Ali Mohamed Amiroudine; Daryl Jesus Arapoc; Zainah Adam; Shafii Khamis

    2015-01-01

    High content screening (HCS) is the convergence between cell-based assays, high-resolution fluorescence imaging, phase-contrast imaging of fixed- or live-cell assays, tissues and small organisms. It has been widely adopted in the pharmaceutical and biotech industries for target identification and validation and as secondary screens to reveal potential toxicities or to elucidate a drugs mechanism of action. By using the ImageXpress® Micro XLS System HCS, the complex network of key players controlling proliferation and apoptosis can be reduced to several sentinel markers for analysis. Cell proliferation and apoptosis are two key areas in cell biology and drug discovery research. Understanding the signaling pathways in cell proliferation and apoptosis is important for new therapeutic discovery because the imbalance between these two events is predominant in the progression of many human diseases, including cancer. The DNA binding dye DAPI is used to determine the nuclear size and nuclear morphology as well as cell cycle phases by DNA content. Images together with MetaXpress® analysis results provide a convenient and easy to use solution to high volume image management. In particular, HCS platform is beginning to have an important impact on early drug discovery, basic research in systems cell biology, and is expected to play a role in personalized medicine or revealing off-target drug effects. (author)

  5. Diurnal fluctuations in cotton leaf carbon export, carbohydrate content, and sucrose synthesizing enzymes.

    Science.gov (United States)

    Hendrix, D L; Huber, S C

    1986-06-01

    In fully expanded leaves of greenhouse-grown cotton (Gossypium hirsutum L., cv Coker 100) plants, carbon export, starch accumulation rate, and carbon exchange rate exhibited different behavior during the light period. Starch accumulation rates were relatively constant during the light period, whereas carbon export rate was greater in the afternoon than in the morning even though the carbon exchange rate peaked about noon. Sucrose levels increased throughout the light period and dropped sharply with the onset of darkness; hexose levels were relatively constant except for a slight peak in the early morning. Sucrose synthase, usually thought to be a degradative enzyme, was found in unusually high activities in cotton leaf. Both sucrose synthase and sucrose phosphate synthetase activities were found to fluctuate diurnally in cotton leaves but with different rhythms. Diurnal fluctuations in the rate of sucrose export were generally aligned with sucrose phosphate synthase activity during the light period but not with sucrose synthase activity; neither enzyme activity correlated with carbon export during the dark. Cotton leaf sucrose phosphate synthase activity was sufficient to account for the observed carbon export rates; there is no need to invoke sucrose synthase as a synthetic enzyme in mature cotton leaves. During the dark a significant correlation was found between starch degradation rate and leaf carbon export. These results indicate that carbon partitioning in cotton leaf is somewhat independent of the carbon exchange rate and that leaf carbon export rate may be linked to sucrose formation and content during the light period and to starch breakdown in the dark.

  6. Digital Mapping of Soil Organic Carbon Contents and Stocks in Denmark

    DEFF Research Database (Denmark)

    Adhikari, Kabindra; Hartemink, Alfred E.; Minasny, Budiman

    2014-01-01

    Estimation of carbon contents and stocks are important for carbon sequestration, greenhouse gas emissions and national carbon balance inventories. For Denmark, we modeled the vertical distribution of soil organic carbon (SOC) and bulk density, and mapped its spatial distribution at five standard ...

  7. Carbon content and C:N ratio of transparent exopolymeric particles (TEP) produced by bubbling exudates of diatoms

    DEFF Research Database (Denmark)

    Mari, Xavier

    1999-01-01

    The carbon content of transparent exopolymeric particles (TEP) was measured in the laboratory in particles produced by bubbling exudates of the diatom Thalassiosira weissflogii, grown under nitrogen non-limited conditions (N:P = 7). The carbon content of these particles (TEP-C) appears to vary...... a coastal area (Kattegat, Denmark), TEP carbon concentration in the surface mixed layer was on the order of 230 ± 150 µg C l-1. This is high relative to other sources of particulate organic carbon (e.g. phytoplankton) and depending on TEP turnover rates, suggests that TEP is an important pathway...... for dissolved organic carbon in coastal seas. The carbon to nitrogen ratio of TEP was measured from particles formed by bubbling exudates of the diatoms T. weissflogii, Skeletonema costatum, Chaetoceros neogracile and C. affinis. Each of these diatom species was grown under various N:P ratios, from N...

  8. Considering Organic Carbon for Improved Predictions of Clay Content from Water Vapor Sorption

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Tuller, Markus; Moldrup, Per

    2014-01-01

    Accurate determination of the soil clay fraction (CF) is of crucial importance for characterization of numerous environmental, agricultural, and engineering processes. Because traditional methods for measurement of the CF are laborious and susceptible to errors, regression models relating the CF...... to water vapor sorption isotherms that can be rapidly measured with a fully automated vapor sorption analyzer are a viable alternative. In this presentation we evaluate the performance of recently developed regression models based on comparison with standard CF measurements for soils with high organic...... carbon (OC) content and propose a modification to improve prediction accuracy. Evaluation of the CF prediction accuracy for 29 soils with clay contents ranging from 6 to 25% and with OC contents from 2.0 to 8.4% showed that the models worked reasonably well for all soils when the OC content was below 2...

  9. Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests

    Science.gov (United States)

    Talhelm, Alan F; Pregitzer, Kurt S; Kubiske, Mark E; Zak, Donald R; Campany, Courtney E; Burton, Andrew J; Dickson, Richard E; Hendrey, George R; Isebrands, J G; Lewin, Keith F; Nagy, John; Karnosky, David F

    2014-01-01

    Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2) and tropospheric ozone (O3) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity (NPP). Elevated CO2 enhanced ecosystem C content by 11%, whereas elevated O3 decreased ecosystem C content by 9%. There was little variation in treatment effects on C content across communities and no meaningful interactions between CO2 and O3. Treatment effects on ecosystem C content resulted primarily from changes in the near-surface mineral soil and tree C, particularly differences in woody tissues. Excluding the mineral soil, cumulative NPP was a strong predictor of ecosystem C content (r2 = 0.96). Elevated CO2 enhanced cumulative NPP by 39%, a consequence of a 28% increase in canopy nitrogen (N) content (g N m−2) and a 28% increase in N productivity (NPP/canopy N). In contrast, elevated O3 lowered NPP by 10% because of a 21% decrease in canopy N, but did not impact N productivity. Consequently, as the marginal impact of canopy N on NPP (ΔNPP/ΔN) decreased through time with further canopy development, the O3 effect on NPP dissipated. Within the mineral soil, there was less C in the top 0.1 m of soil under elevated O3 and less soil C from 0.1 to 0.2 m in depth under elevated CO2. Overall, these results suggest that elevated CO2 may create a sustained increase in NPP, whereas the long-term effect of elevated O3 on NPP will be smaller than expected. However, changes in soil C are not well-understood and limit our ability to predict changes in ecosystem C content. PMID:24604779

  10. Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests.

    Science.gov (United States)

    Talhelm, Alan F; Pregitzer, Kurt S; Kubiske, Mark E; Zak, Donald R; Campany, Courtney E; Burton, Andrew J; Dickson, Richard E; Hendrey, George R; Isebrands, J G; Lewin, Keith F; Nagy, John; Karnosky, David F

    2014-08-01

    Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2 ) and tropospheric ozone (O3 ) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity (NPP). Elevated CO2 enhanced ecosystem C content by 11%, whereas elevated O3 decreased ecosystem C content by 9%. There was little variation in treatment effects on C content across communities and no meaningful interactions between CO2 and O3 . Treatment effects on ecosystem C content resulted primarily from changes in the near-surface mineral soil and tree C, particularly differences in woody tissues. Excluding the mineral soil, cumulative NPP was a strong predictor of ecosystem C content (r(2) = 0.96). Elevated CO2 enhanced cumulative NPP by 39%, a consequence of a 28% increase in canopy nitrogen (N) content (g N m(-2) ) and a 28% increase in N productivity (NPP/canopy N). In contrast, elevated O3 lowered NPP by 10% because of a 21% decrease in canopy N, but did not impact N productivity. Consequently, as the marginal impact of canopy N on NPP (∆NPP/∆N) decreased through time with further canopy development, the O3 effect on NPP dissipated. Within the mineral soil, there was less C in the top 0.1 m of soil under elevated O3 and less soil C from 0.1 to 0.2 m in depth under elevated CO2 . Overall, these results suggest that elevated CO2 may create a sustained increase in NPP, whereas the long-term effect of elevated O3 on NPP will be smaller than expected. However, changes in soil C are not well-understood and limit our ability to predict changes in ecosystem C content. © 2014 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

  11. Influence of moisture content and temperature on degree of carbonation and the effect on Cu and Cr leaching from incineration bottom ash.

    Science.gov (United States)

    Lin, Wenlin Yvonne; Heng, Kim Soon; Sun, Xiaolong; Wang, Jing-Yuan

    2015-09-01

    This study investigated the influence of moisture content and temperature on the degree of carbonation of municipal solid waste (MSW) incineration bottom ash (IBA) from two different incineration plants in Singapore. The initial rate of carbonation was affected by the nominal moisture content used. Carbonation temperature seemed to play a part in changing the actual moisture content of IBA during carbonation, which in turn affected the degree of carbonation. Results showed that 2h of carbonation was sufficient for the samples to reach a relatively high degree of carbonation that was close to the degree of carbonation observed after 1week of carbonation. Both Cu and Cr leaching also showed significant reduction after only 2h of carbonation. Therefore, the optimum moisture content and temperature were selected based on 2h of carbonation. The optimum moisture content was 15% for both incineration plants while the optimum temperature was different for the two incineration plants, at 35°C and 50°C. The effect on Cu and Cr leaching from IBA after accelerated carbonation was evaluated as a function of carbonation time. Correlation coefficient, Pearson's R, was used to determine the dominant leaching mechanism. The reduction in Cu leaching was found to be contributed by both formation of carbonate mineral and reduction of DOC leaching. On the other hand, Cr leaching seemed to be dominantly controlled by pH. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. High content screening in microfluidic devices

    Science.gov (United States)

    Cheong, Raymond; Paliwal, Saurabh; Levchenko, Andre

    2011-01-01

    Importance of the field Miniaturization is key to advancing the state-of-the-art in high content screening (HCS), in order to enable dramatic cost savings through reduced usage of expensive biochemical reagents and to enable large-scale screening on primary cells. Microfluidic technology offers the potential to enable HCS to be performed with an unprecedented degree of miniaturization. Areas covered in this review This perspective highlights a real-world example from the authors’ work of HCS assays implemented in a highly miniaturized microfluidic format. Advantages of this technology are discussed, including cost savings, high throughput screening on primary cells, improved accuracy, the ability to study complex time-varying stimuli, and ease of automation, integration, and scaling. What the reader will gain The reader will understand the capabilities of a new microfluidics-based platform for HCS, and the advantages it provides over conventional plate-based HCS. Take home message Microfluidics technology will drive significant advancements and broader usage and applicability of HCS in drug discovery. PMID:21852997

  13. Facile synthesis of cellulose-based carbon with tunable N content for potential supercapacitor application.

    Science.gov (United States)

    Chen, Zehong; Peng, Xinwen; Zhang, Xiaoting; Jing, Shuangshuang; Zhong, Linxin; Sun, Runcang

    2017-08-15

    Producing hierarchical porous N-doped carbon from renewable biomass is an essential and sustainable way for future electrochemical energy storage. Herein we cost-efficiently synthesized N-doped porous carbon from renewable cellulose by using urea as a low-cost N source, without any activation process. The as-prepared N-doped porous carbon (N-doped PC) had a hierarchical porous structure with abundant macropores, mesopores and micropores. The doping N resulted in more disordered structure, and the doping N content in N-doped PC could be easily tunable (0.68-7.64%). The doping N functionalities could significantly improve the supercapacitance of porous carbon, and even a little amount of doping N (e.g. 0.68%) could remarkably improve the supercapacitance. The as-prepared N-doped PC with a specific surface area of 471.7m 2 g -1 exhibited a high specific capacitance of 193Fg -1 and a better rate capability, as well as an outstanding cycling stability with a capacitance retention of 107% after 5000 cycles. Moreover, the N-doped porous carbon had a high energy density of 17.1Whkg -1 at a power density of 400Wkg -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. High-Melt Carbon-Carbon Coating for Nozzle Extensions

    Science.gov (United States)

    Thompson, James

    2015-01-01

    Carbon-Carbon Advanced Technologies, Inc. (C-CAT), has developed a high-melt coating for use in nozzle extensions in next-generation spacecraft. The coating is composed primarily of carbon-carbon, a carbon-fiber and carbon-matrix composite material that has gained a spaceworthy reputation due to its ability to withstand ultrahigh temperatures. C-CAT's high-melt coating embeds hafnium carbide (HfC) and zirconium diboride (ZrB2) within the outer layers of a carbon-carbon structure. The coating demonstrated enhanced high-temperature durability and suffered no erosion during a test in NASA's Arc Jet Complex. (Test parameters: stagnation heat flux=198 BTD/sq ft-sec; pressure=.265 atm; temperature=3,100 F; four cycles totaling 28 minutes) In Phase I of the project, C-CAT successfully demonstrated large-scale manufacturability with a 40-inch cylinder representing the end of a nozzle extension and a 16-inch flanged cylinder representing the attach flange of a nozzle extension. These demonstrators were manufactured without spalling or delaminations. In Phase II, C-CAT worked with engine designers to develop a nozzle extension stub skirt interfaced with an Aerojet Rocketdyne RL10 engine. All objectives for Phase II were successfully met. Additional nonengine applications for the coating include thermal protection systems (TPS) for next-generation spacecraft and hypersonic aircraft.

  15. Texture and organic carbon contents do not impact amount of carbon protected in Malagasy soils

    Directory of Open Access Journals (Sweden)

    Tantely Razafimbelo

    2013-06-01

    Full Text Available Soil organic carbon (SOC is usually said to be well correlated with soil texture and soil aggregation. These relations generally suggest a physical and physicochemical protection of SOC within soil aggregates and on soil fine particles, respectively. Because there are few experimental evidences of these relations on tropical soils, we tested the relations of soil variables (SOC and soil aggregate contents, and soil texture with the amount of SOC physically protected in aggregates on a set of 15 Malagasy soils. The soil texture, the SOC and water stable macroaggregate (MA contents and the amount of SOC physically protected inside aggregates, calculated as the difference of C mineralized by crushed and intact aggregates, were characterized. The relation between these variables was established. SOC content was significantly correlated with soil texture (clay+fine silt fraction and with soil MA amount while protected SOC content was not correlated with soil MA amount. This lack of correlation might be attributed to the highest importance of physicochemical protection of SOC which is demonstrated by the positive relation between SOC and clay+fine silt fraction.

  16. High performance carbon nanocomposites for ultracapacitors

    Science.gov (United States)

    Lu, Wen

    2012-10-02

    The present invention relates to composite electrodes for electrochemical devices, particularly to carbon nanotube composite electrodes for high performance electrochemical devices, such as ultracapacitors.

  17. Relating black carbon content to reduction of snow albedo

    Science.gov (United States)

    Brandt, R. E.; Warren, S. G.; Clarke, A. D.

    2011-12-01

    In remote snow of the Northern Hemisphere, the levels of soot pollution are in the parts-per-billion (ppb) range, where the effect on albedo is at the level of a few percent. A reduction of albedo by 1-2% is significant for climate but is difficult to detect experimentally, because snow albedo depends on several other variables. In our work to quantify the climatic effect of black carbon (BC) in snow, we therefore do not directly measure the albedo reduction. Instead, we use a two-step procedure: (1) We collect snow samples, melt and filter them, and analyze the filters spectrophotometrically for BC concentration. (2) We use the BC amount from the filter measurement, together with snow grain size, in a radiative transfer model to compute the albedo reduction. Our radiative transfer model uses the discrete ordinates algorithm DISORT 2.0. We have chosen a representative BC size distribution and optical constants, and have incorporated those of mineral dust as well. While a given mass of BC causes over an order of magnitude more snow albedo reduction compared to dust, a snowpack containing dust mutes the albedo-reducing effect of BC. Because the computed reduction of snow albedo is model-based, it requires experimental verification. We doubt that direct measurement of albedo-reduction will be feasible in nature, because of the vertical variation of both snow grain size and soot content, and because the natural soot content is small. We conclude that what is needed is an artificial snowpack, with uniform grain size and large uniform soot content (ppm not ppb), to produce a large signal on albedo. We have chosen to pursue this experiment outdoors rather than in the laboratory, for the following reasons: (1) The snowpack in the field of view is uniformly illuminated if the source of radiation is the Sun. (2) Visible radiation penetrates into the snow, so photons emerge horizontally distant from where they entered. In the limited width of a laboratory snowpack, radiation

  18. Effect of carbon content on the microstructure and mechanical properties of superfine Ti(C, N)-based cermets

    International Nuclear Information System (INIS)

    Liu Ning; Liu Xuesong; Zhang Xiaobo; Zhu Longwei

    2008-01-01

    As a new kind of tool materials which appeared in the seventies last century, the Ti (C, N)-based cermets have been widely used in recent years due to many of its good properties. The microstructure of Ti(C, N)-based cermets with various carbon content were studied using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffractometry (XRD). Vickers hardness and transverse rupture strength (TRS) were also measured. An increased carbon content resulted in the finer grain size, decreased solution strength of tungsten and molybdenum in the binder phase, and a higher volume fraction of heavy (Ti, Mo, W)(C,N) cores. If the addition of carbon content is too little or too much, the phase composition of material will deviate from the normal dual phase section and lead to the formation of the third phase: η-phase if the carbon content is too low or dissociative carbon if the carbon content is too high. And the formation of the third phase will remarkably deteriorate the mechanical properties of cermets

  19. Biomass Carbon Content in Schima- Castanopsis Forest of Midhills of Nepal: A Case Study from Jaisikuna Community Forest, Kaski

    Directory of Open Access Journals (Sweden)

    Sushma Tripathi

    2018-01-01

    Full Text Available Community forests of Nepal’s midhills have high potentiality to sequester carbon. This paper tries to analyze the biomass carbon stock in Schima-Castanopsis forest of Jaisikuna community forests of Kaski district, Nepal. Forest area was divided into two blocks and 18 sample plots (9 in each block which were laid randomly. Diameter at Breast Height (DBH and height of trees (DBH≥5cm were measured using the DBH tape and clinometer. Leaf litter, herbs, grasses and seedlings were collected from 1*1m2 plot and fresh weight was taken. For calculating carbon biomass is multiplied by default value 0.47. The AGTB carbon content of Chilaune, Katus and other species were found 19.56 t/ha, 18.66 t/ha and 3.59 t/ha respectively. The AGTB of Chilaune dominated, Katus dominated and whole forest was found 43.78 t/ha, 39.83 t/ha and 41.81 t/ha respectively. Carbon content at leaf litter, herbs, grasses and seedlings was found 2.73 t/ha. Below ground biomass carbon at whole forest was found 6.27 t/ha. Total biomass and carbon of the forest was found 108.09 t/ha and 50.80 t/ha respectively. Difference in biomass and carbon content at Chilaune dominated block and Katus dominated block was found insignificant. This study record very low biomass carbon content than average of Nepal's forest but this variation in carbon stock is not necessarily due to dominant species present in the forest. Carbon estimation at forest of different elevation, aspect and location are recommended for further research. International Journal of EnvironmentVolume-6, Issue-4, Sep-Nov 2017, page: 72-84

  20. Digital mapping of soil organic carbon contents and stocks in Denmark.

    Science.gov (United States)

    Adhikari, Kabindra; Hartemink, Alfred E; Minasny, Budiman; Bou Kheir, Rania; Greve, Mette B; Greve, Mogens H

    2014-01-01

    Estimation of carbon contents and stocks are important for carbon sequestration, greenhouse gas emissions and national carbon balance inventories. For Denmark, we modeled the vertical distribution of soil organic carbon (SOC) and bulk density, and mapped its spatial distribution at five standard soil depth intervals (0-5, 5-15, 15-30, 30-60 and 60-100 cm) using 18 environmental variables as predictors. SOC distribution was influenced by precipitation, land use, soil type, wetland, elevation, wetness index, and multi-resolution index of valley bottom flatness. The highest average SOC content of 20 g kg(-1) was reported for 0-5 cm soil, whereas there was on average 2.2 g SOC kg(-1) at 60-100 cm depth. For SOC and bulk density prediction precision decreased with soil depth, and a standard error of 2.8 g kg(-1) was found at 60-100 cm soil depth. Average SOC stock for 0-30 cm was 72 t ha(-1) and in the top 1 m there was 120 t SOC ha(-1). In total, the soils stored approximately 570 Tg C within the top 1 m. The soils under agriculture had the highest amount of carbon (444 Tg) followed by forest and semi-natural vegetation that contributed 11% of the total SOC stock. More than 60% of the total SOC stock was present in Podzols and Luvisols. Compared to previous estimates, our approach is more reliable as we adopted a robust quantification technique and mapped the spatial distribution of SOC stock and prediction uncertainty. The estimation was validated using common statistical indices and the data and high-resolution maps could be used for future soil carbon assessment and inventories.

  1. Contents

    Directory of Open Access Journals (Sweden)

    Editor IJRED

    2012-11-01

    Full Text Available International Journal of Renewable Energy Development www.ijred.com Volume 1             Number 3            October 2012                ISSN 2252- 4940   CONTENTS OF ARTICLES page Design and Economic Analysis of a Photovoltaic System: A Case Study 65-73 C.O.C. Oko , E.O. Diemuodeke, N.F. Omunakwe, and E. Nnamdi     Development of Formaldehyde Adsorption using Modified Activated Carbon – A Review 75-80 W.D.P Rengga , M. Sudibandriyo and M. Nasikin     Process Optimization for Ethyl Ester Production in Fixed Bed Reactor Using Calcium Oxide Impregnated Palm Shell Activated Carbon (CaO/PSAC 81-86 A. Buasri , B. Ksapabutr, M. Panapoy and N. Chaiyut     Wind Resource Assessment in Abadan Airport in Iran 87-97 Mojtaba Nedaei       The Energy Processing by Power Electronics and its Impact on Power Quality 99-105 J. E. Rocha and B. W. D. C. Sanchez       First Aspect of Conventional Power System Assessment for High Wind Power Plants Penetration 107-113 A. Merzic , M. Music, and M. Rascic   Experimental Study on the Production of Karanja Oil Methyl Ester and Its Effect on Diesel Engine 115-122 N. Shrivastava,  , S.N. Varma and M. Pandey  

  2. Organic carbon, nitrogen and phosphorus contents of some soils of kaliti tea-estate, Bangladesh

    International Nuclear Information System (INIS)

    Ahmed, M. S.; Shahin, M. M. H.; Sanaullah, A. F. M.

    2005-01-01

    Some soil samples were collected from Kaliti Tea-Estate of Moulvibazar district, Bangladesh. Total nitrogen, organic carbon, organic matter, carbon-nitrogen ratio and available phosphorus content of the collected soil samples of different depths and of different topographic positions have been determined. Total nitrogen was found 0.07 to 0.12 % organic carbon and organic matter content found to vary from 0.79 to 1.25 and 1.36 to 2.15 % respectively. Carbon-nitrogen ratio of these soils varied from 9.84 to 10.69, while available phosphorus content varied from 2.11 to 4.13 ppm. (author)

  3. Optimization of supercritical carbon dioxide extraction of Piper Betel Linn leaves oil and total phenolic content

    Science.gov (United States)

    Aziz, A. H. A.; Yunus, M. A. C.; Arsad, N. H.; Lee, N. Y.; Idham, Z.; Razak, A. Q. A.

    2016-11-01

    Supercritical Carbon Dioxide (SC-CO2) Extraction was applied to extract piper betel linn leaves. The piper betel leaves oil was used antioxidant, anti-diabetic, anticancer and antistroke. The aim of this study was to optimize the conditions of pressure, temperature and flowrate for oil yield and total phenolic content. The operational conditions of SC-CO2 studied were pressure (10, 20, 30 MPa), temperature (40, 60, 80 °C) and flowrate carbon dioxide (4, 6, 8 mL/min). The constant parameters were average particle size and extraction regime, 355pm and 3.5 hours respectively. First order polynomial expression was used to express the extracted oil while second order polynomial expression was used to express the total phenolic content and the both results were satisfactory. The best conditions to maximize the total extraction oil yields and total phenolic content were 30 MPa, 80 °C and 4.42 mL/min leading to 7.32% of oil and 29.72 MPa, 67.53 °C and 7.98 mL/min leading to 845.085 mg GAE/g sample. In terms of optimum condition with high extraction yield and high total phenolic content in the extracts, the best operating conditions were 30 MPa, 78 °C and 8 mL/min with 7.05% yield and 791.709 mg gallic acid equivalent (GAE)/g sample. The most dominant condition for extraction of oil yield and phenolic content were pressure and CO2 flowrate. The results show a good fit to the proposed model and the optimal conditions obtained were within the experimental range with the value of R2 was 96.13% for percentage yield and 98.52% for total phenolic content.

  4. Novel porous carbon materials with ultrahigh nitrogen contents for selective CO 2 capture

    KAUST Repository

    Zhao, Yunfeng; Zhao, Lan; Yao, Kexin; Yang, Yang; Zhang, Qiang; Han, Yu

    2012-01-01

    Nitrogen-doped carbon materials were prepared by a nanocasting route using tri-continuous mesoporous silica IBN-9 as a hard template. Rationally choosing carbon precursors and carefully controlling activation conditions result in an optimized material denoted as IBN9-NC1-A, which possesses a very high nitrogen doping concentration (∼13 wt%) and a large surface area of 890 m 2 g -1 arising from micropores (<1 nm). It exhibits an excellent performance for CO 2 adsorption over a wide range of CO 2 pressures. Specifically, its equilibrium CO 2 adsorption capacity at 25 °C reaches up to 4.50 mmol g -1 at 1 bar and 10.53 mmol g -1 at 8 bar. In particular, it shows a much higher CO 2 uptake at low pressure (e.g. 1.75 mmol g -1 at 25 °C and 0.2 bar) than any reported carbon-based materials, owing to its unprecedented nitrogen doping level. The high nitrogen contents also give rise to significantly enhanced CO 2/N 2 selectivities (up to 42), which combined with the high adsorption capacities, make these new carbon materials promising sorbents for selective CO 2 capture from power plant flue gas and other relevant applications. © 2012 The Royal Society of Chemistry.

  5. Molecular indicators for palaeoenvironmental change in a Messinian evaporitic sequence (Vena del Gesso, Italy). II: High-resolution variations in abundances and 13C contents of free and sulphur-bound carbon skeletons in a single marl bed

    Science.gov (United States)

    Kenig, F.; Damste, J. S.; Frewin, N. L.; Hayes, J. M.; De Leeuw, J. W.

    1995-01-01

    The extractable organic matter of 10 immature samples from a marl bed of one evaporitic cycle of the Vena del Gesso sediments (Gessoso-solfifera Fm., Messinian, Italy) was analyzed quantitatively for free hydrocarbons and organic sulphur compounds. Nickel boride was used as a desulphurizing agent to recover sulphur-bound lipids from the polar and asphaltene fractions. Carbon isotopic compositions (delta vs PDB) of free hydrocarbons and of S-bound hydrocarbons were also measured. Relationships between these carbon skeletons, precursor biolipids, and the organisms producing them could then be examined. Concentrations of S-bound lipids and free hydrocarbons and their delta values were plotted vs depth in the marl bed and the profiles were interpreted in terms of variations in source organisms, 13 C contents of the carbon source, and environmentally induced changes in isotopic fractionation. The overall range of delta values measured was 24.7%, from -11.6% for a component derived from green sulphur bacteria (Chlorobiaceae) to -36.3% for a lipid derived from purple sulphur bacteria (Chromatiaceae). Deconvolution of mixtures of components deriving from multiple sources (green and purple sulphur bacteria, coccolithophorids, microalgae and higher plants) was sometimes possible because both quantitative and isotopic data were available and because either the free or S-bound pool sometimes appeared to contain material from a single source. Several free n-alkanes and S-bound lipids appeared to be specific products of upper-water-column primary producers (i.e. algae and cyanobacteria). Others derived from anaerobic photoautotrophs and from heterotrophic protozoa (ciliates), which apparently fed partly on Chlorobiaceae. Four groups of n-alkanes produced by algae or cyanobacteria were also recognized based on systematic variations of abundance and isotopic composition with depth. For hydrocarbons probably derived from microalgae, isotopic variations are well correlated with

  6. Diffusion in a pure, high-vacancy-content crystal

    International Nuclear Information System (INIS)

    McKee, R.A.

    1981-01-01

    The idea that vacancies can follow a nonrandom walk in a solid has been developed and put into a quantitative form for diffusion in a pure, high-vacancy-content crystal. Intrinsic and tracer diffusion in a metal have been analyzed, and the electrical mobility in an ionic solid has been expressed in terms of the tracer diffusion coefficient and the separate correlation factors for atoms and vacancies. The description uses classical methods of diffusion theory, and generalized results that account for nonrandom vacancy walk have been shown to reduce to those obtained by Howard and Lidiard in a system where the vacancy moves randomly as an isolated point defect. Experimental data for carbon diffusion in fcc iron have been examined to illustrate an interstitial-vacancy analogy that was used in this analysis, and the general result has been applied specifically to discuss vacancy diffusion in Fe/sub 1-x/S

  7. Influence of alkali, silicate, and sulfate content of carbonated concrete pore solution on mild steel corrosion behavior

    International Nuclear Information System (INIS)

    L'Hostis, V.; Huet, B.; Tricheux, L.; Idrissi, H.

    2010-01-01

    The increase in the rebar corrosion rate due to the concrete carbonation is the major cause of reinforced concrete degradation. The aim of this study was to investigate the corrosion behavior of mild steel rebars in simulated carbonated concrete solution. For this purpose, thermodynamic calculations, electrochemical techniques, gravimetric measurements, and surface analyses were used. Thermodynamic investigations of the nature of the interstitial solution provides an estimation of the influence of sulfate (SO 4 2- ) and alkali (Na + , K + ) content on carbonate alkalinity of the CO 2 /H 2 O open system (pCO 2 =0. 3 mbar). in this system, calcium-silicate hydrates (C-S-H) remain thermodynamically unstable and amorphous silica controls silicate aqueous content at 100 ppm. Electrochemical results highlight a decrease in the corrosion rate with increasing carbonate alkalinity and the introduction of silicate. The introduction of sulfate at fixed carbonate alkalinity shows a dual effect: at high carbonate alkalinity, the corrosion rate is increased whereas at low carbonate alkalinity, corrosion rate is decreased. Those results are supported by surface analysis. Authors conclude that silicate and sulfate release from cement hydrates and fixation of alkali on carbonated hydrates are key parameters to estimate mild steel corrosion in carbonated concrete. (authors)

  8. Determination of Hydrogen and Carbon contents in crude oil and Petroleum fractions by NMR Spectroscopy

    International Nuclear Information System (INIS)

    Khadim, Mohammad A.; Wolny, R.A.; Al-Dhuwaihi, Abdullah S.; Al-Hajri, E.A.; Al-Ghamdi, M.A.

    2003-01-01

    Proton and carbon-13 NMR spectroscopic methods were developed for determining hydrogen and carbon contents in petroleum products. These methods are applicable to a wide of petroleum streams. A new reference standard, bis (trimethylsilyl) methane, BTMSM, is introduced fro both proton and carbon-13 NMR for the first time, which offers several advantages over those customarily employed. These methods are important for the calculation of the mass balance and hydrogen consumption in pilot plant studies. Unlike the ASTM D-5291 combustion method, the NMR methods also allow for the measurement of hydrogen and carbon content in low boiling fractions and those containing hydrogen as low as 1%. The NMR methods can also determine aromatic and aliphatic hydrogens carbons in a given sample without additional experimentation. The precision and accuracy of the newly developed NMR methods are compared with those of currently employed ASTM D-5291 combustion method. Using the proton NMR method, hydrogen content was determined in fifteen model compounds and sixty-eight petroleum fractions. The NMR and ASTM methods show an agreement within +5%for 48 out of a total number of 68 oil fractions. Using carbon-13 NMR, the carbon content was determined for four representative compounds and three fractions of crude oil. Both carbon-13 NMR and ASTM methods give comparable carbon content in model compounds and crude oil fractions. (author)

  9. Carbon nanomaterials for high-performance supercapacitors

    OpenAIRE

    Tao Chen; Liming Dai

    2013-01-01

    Owing to their high energy density and power density, supercapacitors exhibit great potential as high-performance energy sources for advanced technologies. Recently, carbon nanomaterials (especially, carbon nanotubes and graphene) have been widely investigated as effective electrodes in supercapacitors due to their high specific surface area, excellent electrical and mechanical properties. This article summarizes the recent progresses on the development of high-performance supercapacitors bas...

  10. Effect of water content and organic carbon on remote sensing of crop residue cover

    Science.gov (United States)

    Serbin, G.; Hunt, E. R., Jr.; Daughtry, C. S. T.; McCarty, G. W.; Brown, D. J.; Doraiswamy, P. C.

    2009-04-01

    Crop residue cover is an important indicator of tillage method. Remote sensing of crop residue cover is an attractive and efficient method when compared with traditional ground-based methods, e.g., the line-point transect or windshield survey. A number of spectral indices have been devised for residue cover estimation. Of these, the most effective are those in the shortwave infrared portion of the spectrum, situated between 1950 and 2500 nm. These indices include the hyperspectral Cellulose Absorption Index (CAI), and advanced multispectral indices, i.e., the Lignin-Cellulose Absorption (LCA) index and the Shortwave Infrared Normalized Difference Residue Index (SINDRI), which were devised for the NASA Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor. Spectra of numerous soils from U.S. Corn Belt (Indiana and Iowa) were acquired under wetness conditions varying from saturation to oven-dry conditions. The behavior of soil reflectance with water content was also dependent on the soil organic carbon content (SOC) of the soils, and the location of the spectral bands relative to significant water absorptions. High-SOC soils showed the least change in spectral index values with increase in soil water content. Low-SOC soils, on the other hand, showed measurable difference. For CAI, low-SOC soils show an initial decrease in index value followed by an increase, due to the way that water content affects CAI spectral bands. Crop residue CAI values decrease with water content. For LCA, water content increases decrease crop residue index values and increase them for soils, resulting in decreased contrast. SINDRI is also affected by SOC and water content. As such, spatial information on the distribution of surface soil water content and SOC, when used in a geographic information system (GIS), will improve the accuracy of remotely-sensed crop residue cover estimates.

  11. Analysis of Seasonal Soil Organic Carbon Content at Bukit Jeriau Forest, Fraser Hill, Pahang

    International Nuclear Information System (INIS)

    Ahmad Adnan Mohamed; Ahmad Adnan Mohamed; Sahibin Abd Rahim; David Allan Aitman; Mohd Khairul Amri Kamarudin; Mohd Khairul Amri Kamarudin

    2016-01-01

    Soil carbon is the carbon held within the soil, primarily in association with its organic content. The total soil organic carbon study was determined in a plot at Bukit Jeriau forest in Bukit Fraser, Pahang, Malaysia. The aim of this study is to determine the changing of soil organic carbon between wet season and dry season. Soil organic carbon was fined out using titrimetric determination. The soil organic carbon content in wet season is 223.24 t/ ha while dry season is 217.90 t/ ha. The soil pH range in wet season is between 4.32 to 4.45 and in dry season in 3.95 to 4.08 which is considered acidic. Correlation analysis showed that soil organic carbon value is influenced by pH value and climate. Correlation analysis between clay and soil organic carbon with depth showed positively significant differences and clay are very much influenced soil organic carbon content. Correlation analysis between electrical conductivity and soil organic carbon content showed negative significantly difference on wet season and positively significant different in dry season. (author)

  12. Calculation method for determination of carbon in the peatand moss litter of forest swamps by ash content of plant substrates

    Directory of Open Access Journals (Sweden)

    T. T. Efremova

    2016-12-01

    Full Text Available Studies were carried out in the lowmountain part of the Kuznetsk Alatau. The spruce stands were studied in the peaty valley of river Tunguzhul and swamp near Agaskyr Lake (valley of river Pechische, basin of river Black Iyus. The objects belong to the group of high ash content flood plain peat lands of cryogenicseries. We have done the evaluation of organic carbon response to physical-chemical properties – decomposition degree, ash content, and bulk density, connected together (r – 0.5–0.7, that in contrast to carbon, is easy determined analytically. Received results according to stepwise regression analysis characterize the strong conditionality predictors of carbon: multiple determination index R2 – 0.86. The highest partial correlation coefficient with the response belongs to the ash content in range (5–68 %. Partial correlation coefficient values of bulk density and decomposition degree is not significant. The determination index (R2 – 0.93, constant and negative coefficient of pair regression analysis are highly significant and evidence of the strong bond of carbon and organic substrate ash content. The relative error of approximation is in the range of 2–8 % and characterizes the high accuracy of prognosis. Including only one indicator (ash content in the calculation formula makes it convenient and simple in practical application for the carbon content prediction on the forest litter, modern peat soils, buried peat and peat-mineral formations with ash content of 5–68 %. We are the first to present the geochemical characteristics of forest swamps peat mine for the KuznetskAlatau intermountain basins.

  13. Filterability of corrosion products formed between carbon steel and water. Influence of temperature and oxygen content

    International Nuclear Information System (INIS)

    Kelen, T.; Falk, I.

    1975-09-01

    A laboratory investigation has been made for the purpose of studying the influence of temperature and oxygen content on the filterability of corrosion products formed between carbon-steel and water. The experiments were performed in a high temperature loop where the water is initially heated in a pre-heater, then cooled and finally filtered. The corrosion products were transferred to thewater from a carbon-steel surface that had previously been neutron activated and the amount of iron present was determined from measurements of the γ-radiation emitted by Fe-59. Filterability was then computed as the ratio between the total amount of iron in the water phase and the amount of iron retained on the filter. The investigation covers a series of experiments at filtering temperatures of 20, 90 and 160 dec G, pre-heater temperatures up to 300 deg C and oxygen contents of 10 and 300 ppb O 2 . In addition the extent of iron deposition in the pre-heater and heat regulator has been determined after each series of experiments. Filterability exhibited a pronounced dependence upon both the filter and pre-heater temperatures and also upon the oxygen content. Among the conclusions to which the results lead is the observation that a strict comparison of filterability values for the fraction of corrosion products in cooled water samples is impossible when these are taken from 1) different sections of a high temperature system 2) a single sampling point while the system is being run up 3) two separate systems (e.g. steam boilers) operated at different temperatures 4) two separate systems operated at different oxygen contents. It accordingly appears advizable to restrict the use of cold-filtered samples from conventional steam-raising plants to the comparison of values relating to a single sampling point under constant operating conditions. (author)

  14. Thallium and its contents in Remata carbonate rocks

    Directory of Open Access Journals (Sweden)

    Kondelová Marcela

    1996-09-01

    Full Text Available The article presents at first the list of thallium own minerals and its isomorphic content in other minerals, especially in Slovakian ore deposits. This trace element was found in numerous dolomite-rock samples from Remata massif near Handlová. An interesting level of Tl content was analyzed in nonsilicified rocks; the highest content of Tl (and Ag are along the E – W line of disturbance. The presence of thallium in some limonitic aggregates in close Kremnica-gold deposit indicate any continuous relation. Some similarities to type gold deposits Carlin ( USA are discussed, even if no gold and discrete thallium phases were in Remata determined yet.

  15. Topsoil organic carbon content of Europe, a new map based on a generalised additive model

    Science.gov (United States)

    de Brogniez, Delphine; Ballabio, Cristiano; Stevens, Antoine; Jones, Robert J. A.; Montanarella, Luca; van Wesemael, Bas

    2014-05-01

    There is an increasing demand for up-to-date spatially continuous organic carbon (OC) data for global environment and climatic modeling. Whilst the current map of topsoil organic carbon content for Europe (Jones et al., 2005) was produced by applying expert-knowledge based pedo-transfer rules on large soil mapping units, the aim of this study was to replace it by applying digital soil mapping techniques on the first European harmonised geo-referenced topsoil (0-20 cm) database, which arises from the LUCAS (land use/cover area frame statistical survey) survey. A generalized additive model (GAM) was calibrated on 85% of the dataset (ca. 17 000 soil samples) and a backward stepwise approach selected slope, land cover, temperature, net primary productivity, latitude and longitude as environmental covariates (500 m resolution). The validation of the model (applied on 15% of the dataset), gave an R2 of 0.27. We observed that most organic soils were under-predicted by the model and that soils of Scandinavia were also poorly predicted. The model showed an RMSE of 42 g kg-1 for mineral soils and of 287 g kg-1 for organic soils. The map of predicted OC content showed the lowest values in Mediterranean countries and in croplands across Europe, whereas highest OC content were predicted in wetlands, woodlands and in mountainous areas. The map of standard error of the OC model predictions showed high values in northern latitudes, wetlands, moors and heathlands, whereas low uncertainty was mostly found in croplands. A comparison of our results with the map of Jones et al. (2005) showed a general agreement on the prediction of mineral soils' OC content, most probably because the models use some common covariates, namely land cover and temperature. Our model however failed to predict values of OC content greater than 200 g kg-1, which we explain by the imposed unimodal distribution of our model, whose mean is tilted towards the majority of soils, which are mineral. Finally, average

  16. Ultrahigh Ductility, High-Carbon Martensitic Steel

    Science.gov (United States)

    Qin, Shengwei; Liu, Yu; Hao, Qingguo; Zuo, Xunwei; Rong, Yonghua; Chen, Nailu

    2016-10-01

    Based on the proposed design idea of the anti-transformation-induced plasticity effect, both the additions of the Nb element and pretreatment of the normalization process as a novel quenching-partitioning-tempering (Q-P-T) were designed for Fe-0.63C-1.52Mn-1.49Si-0.62Cr-0.036Nb hot-rolled steel. This high-carbon Q-P-T martensitic steel exhibits a tensile strength of 1890 MPa and elongation of 29 pct accompanied by the excellent product of tensile and elongation of 55 GPa pct. The origin of ultrahigh ductility for high-carbon Q-P-T martensitic steel is revealed from two aspects: one is the softening of martensitic matrix due to both the depletion of carbon in the matensitic matrix during the Q-P-T process by partitioning of carbon from supersaturated martensite to retained austenite and the reduction of the dislocation density in a martensitic matrix by dislocation absorption by retained austenite effect during deformation, which significantly enhances the deformation ability of martensitic matrix; another is the high mechanical stability of considerable carbon-enriched retained austenite, which effectively reduces the formation of brittle twin-type martensite. This work verifies the correctness of the design idea of the anti-TRIP effect and makes the third-generation advanced high-strength steels extend to the field of high-carbon steels from low- and medium-carbon steels.

  17. Conductive additive content balance in Li-ion battery cathodes: Commercial carbon blacks vs. in situ carbon from LiFePO{sub 4}/C composites

    Energy Technology Data Exchange (ETDEWEB)

    Palomares, Veronica; Goni, Aintzane; Muro, Izaskun Gil de; Rojo, Teofilo [Departamento de Quimica Inorganica, Universidad del Pais Vasco UPV/EHU, P.O. Box. 644, 48080, Bilbao (Spain); de Meatza, Iratxe; Bengoechea, Miguel [Energy Department, CIDETEC-IK4, P Miramon 196, Parque Tecnologico de San Sebastian, 20009, San Sebastian (Spain); Cantero, Igor [Departamento I+D+i Nuevas Tecnologias, CEGASA, Artapadura, 11, 01013 Vitoria-Gasteiz (Spain)

    2010-11-15

    Two samples of commercial conducting carbon black and the carbon generated in situ during LiFePO{sub 4}/C composite synthesis from citric acid are studied, with the aim of finding out whether carbon from the composite can fulfil the same function as carbon black in the electrode blend for a Li-ion battery. For this purpose, the carbon samples are analyzed by several techniques, such as X-ray diffraction, Raman spectroscopy, transmission electron microscopy, granulometry, BET specific area and conductivity measurements. Different cathode compositions and component proportions are tested for pellet and cast electrodes. Electrochemical results show that a moderate reduction of commercial carbon black content in both kinds of cathodes, by adding more LiFePO{sub 4}/C composite, enhanced the electrochemical behaviour by around 10%. In situ generated carbon can partially replace commercial conducting carbon black because its high specific surface probably enhances electrolyte penetration into the cathode, but it is always necessary to maintain a minimum amount of carbon black that provides better conductivity in order to obtain a good electrochemical response. (author)

  18. Observation of WC grain shapes determined by carbon content during liquid phase sintering of WC-Co alloys

    International Nuclear Information System (INIS)

    Sona Kim; Hyoun-Ee Kim; Seok-Hee Han; Jong-Ku Park

    2001-01-01

    In the composite materials of WC-Co alloys, the faceted WC grains as a hard phase are dispersed in the ductile matrix of cobalt. Properties of WC-Co alloys are affected by microstructural factors such as volume fraction of WC phase, size of WC grains, and carbon content (kinds of constituent phases). Although the properties of WC-Co alloys are inevitably affected by the shape of WC grains, the shape of WC grains has not been thrown light on the properties of WC-Co alloys yet, because it has been regarded to have a uniform shape regardless of alloy compositions. It is proved that the WC grains have various shapes varying reversibly with carbon content in the sintered WC-Co compacts. This dependency of grain shape on the carbon content is attributed to asymmetric atomic structure of WC crystal. The {10 1 - 0} prismatic planes are distinguished into two groups with different surface energy according to their atomic structures. The prismatic planes of high surface energy tend to disappear in the compacts with high carbon content. In addition, these high energy prismatic planes tend to split into low energy surfaces in the large WC grains. (author)

  19. Size and Carbon Content of Sub-seafloor Microbial Cells at Landsort Deep, Baltic Sea

    DEFF Research Database (Denmark)

    Braun, Stefan; Morono, Yuki; Littmann, Sten

    2016-01-01

    determined the volume and the carbon content of microbial cells from a marine sediment drill core retrieved by the Integrated Ocean Drilling Program (IODP), Expedition 347, at Landsort Deep, Baltic Sea. To determine their shape and volume, cells were separated from the sediment matrix by multi-layer density......-specific carbon content was 19–31 fg C cell−1, which is at the lower end of previous estimates that were used for global estimates of microbial biomass. The cell-specific carbon density increased with sediment depth from about 200 to 1000 fg C μm−3, suggesting that cells decrease their water content and grow...... small cell sizes as adaptation to the long-term subsistence at very low energy availability in the deep biosphere. We present for the first time depth-related data on the cell volume and carbon content of sedimentary microbial cells buried down to 60 m below the seafloor. Our data enable estimates...

  20. Relationship of subseafloor microbial diversity to sediment age and organic carbon content

    Science.gov (United States)

    Walsh, E. A.; Kirkpatrick, J. B.; Sogin, M. L.; D'Hondt, S. L.

    2013-12-01

    Our tag pyrosequencing investigation of four globally distant sites reveals sediment age and total organic carbon content to be significant components in understanding subseafloor diversity. Our sampling locations include two sites from high-productivity regions (Indian Ocean and Bering Sea) and two from moderate-productivity (eastern and central equatorial Pacific Ocean). Sediment from the high-productivity sites has much higher TOC than sediment from the moderate-productivity equatorial sites. We applied a high-resolution 16S V4-V6 tag pyrosequencing approach to 24 bacterial and 17 archaeal samples, totaling 602,502 reads. We identified1,291 archaeal and 15,910 bacterial OTUs (97%) from these reads. We analyzed bacterial samples from all four sites in addition to archaeal samples from our high productivity sites. These high productivity, high TOC sites have a pronounced methane-rich sulfate-free zone at depth from which archaea have been previously considered to dominate (Biddle et al., 2006). At all four locations, microbial diversity is highest near the seafloor and drops rapidly to low but stable values with increasing sediment depth. The depth at which diversity stabilizes varies greatly from site to site, but the age at which it stabilizes is relatively constant. At all four sites, diversity reaches low stable values a few hundred thousand years after sediment deposition. The sites with high total organic carbon (high productivity sites) generally exhibit higher diversity at each sediment age than the sites with lower total organic carbon (moderate-productivity sites). Archaeal diversity is lower than bacterial diversity at every sampled depth. Biddle, J.F., Lipp, J.S., Lever, M.A., Lloyd, K.G., Sørensen, K.B., Anderson, R. et al. (2006) Heterotrophic Archaea dominate sedimentary subsurface ecosystems off Peru. PNAS 103: 3846-3851.

  1. High-surface-area active carbon

    International Nuclear Information System (INIS)

    O'Grady, T.M.; Wennerberg, A.N.

    1986-01-01

    This paper describes the preparation and properties of a unique active carbon having exceptionally high surface areas, over 2500 m 2 /gm, and extraordinary adsorptive capacities. The carbon is made by a direct chemical activation route in which petroleum coke or other carbonaceous sources are reacted with excess potassium hydroxide at 400 0 to 500 0 C to an intermediate product that is subsequently pyrolyzed at 800 0 to 900 0 C to active carbon containing potassium salts. These are removed by water washing and the carbon is dried to produce a powdered product. A granular carbon can also be made by further processing the powdered carbon by using specialized granulation techniques. Typical properties of the carbon include Iodine Numbers of 3000 to 3600, methylene blue adsorption of 650 to 750 mg/gm, pore volumes of 2.0 to 2.6 cc/gm and less than 3.0% ash. This carbon's high adsorption capacities make it uniquely suited for numerous demanding applications in the medical area, purifications, removal of toxic substances, as catalyst carriers, etc

  2. Can mud (silt and clay) concentration be used to predict soil organic carbon content within seagrass ecosystems?

    KAUST Repository

    Serrano, Oscar

    2016-09-07

    The emerging field of blue carbon science is seeking cost-effective ways to estimate the organic carbon content of soils that are bound by coastal vegetated ecosystems. Organic carbon (C-org) content in terrestrial soils and marine sediments has been correlated with mud content (i.e., silt and clay, particle sizes <63 mu m), however, empirical tests of this theory are lacking for coastal vegetated ecosystems. Here, we compiled data (n = 1345) on the relationship between C-org and mud contents in seagrass ecosystems (79 cores) and adjacent bare sediments (21 cores) to address whether mud can be used to predict soil C-org content. We also combined these data with the delta C-13 signatures of the soil C-org to understand the sources of Corg stores. The results showed that mud is positively correlated with soil C-org content only when the contribution of seagrass-derived C-org to the sedimentary C-org pool is relatively low, such as in small and fast-growing meadows of the genera Zostera, Halodule and Halophila, and in bare sediments adjacent to seagrass ecosystems. In large and long-living seagrass meadows of the genera Posidonia and Amphibolis there was a lack of, or poor relationship between mud and soil C-org content, related to a higher contribution of seagrass-derived C-org to the sedimentary C-org pool in these meadows. The relatively high soil C-org contents with relatively low mud contents (e.g., mud-C-org saturation) in bare sediments and Zostera, Halodule and Halophila meadows was related to significant allochthonous inputs of terrestrial organic matter, while higher contribution of seagrass detritus in Amphibolis and Posidonia meadows disrupted the correlation expected between soil C-org and mud contents. This study shows that mud is not a universal proxy for blue carbon content in seagrass ecosystems, and therefore should not be applied generally across all seagrass habitats. Mud content can only be used as a proxy to estimate soil C-org content for

  3. Internal friction in iron-aluminium alloys having a high aluminium content

    International Nuclear Information System (INIS)

    Hillairet, J.; Delaplace, J.; Silvent, A.

    1966-01-01

    By using a torsion pendulum to measure the internal friction of iron-aluminium alloys containing between 25 and 50 atom per cent of aluminium, it has been possible to show the existence of three damping peaks due to interstitial carbon. Their evolution is followed as a function of the carbon content, of the thermal treatment and of the aluminium content. A model based on the preferential occupation of tetrahedral sites is proposed as an interpretation of the results. A study of the Zener peak in these substitution alloys shows also that a part of the short distance disorder existing at high temperatures can be preserved by quenching. (author) [fr

  4. On high temperature strength of carbon steels

    International Nuclear Information System (INIS)

    Ichinose, Hiroyuki; Tamura, Manabu; Kanero, Takahiro; Ihara, Yoshihito

    1977-01-01

    In the steels for high temperature use, the oxidation resistance is regarded as important, but carbon steels show enough oxidation resistance to be used continuously at the temperature up to 500 deg. C if the strength is left out of consideration, and up to 450 deg. C even when the strength is taken into account. Moreover, the production is easy, the workability and weldability are good, and the price is cheap in carbon steels as compared with alloy steels. In the boilers for large thermal power stations, 0.15-0.30% C steels are used for reheater tubes, main feed water tubes, steam headers, wall water tubes, economizer tubes, bypass pipings and others, and they account for 70% of all steel materials used for the boilers of 350 MW class and 30% in 1000 MW class. The JIS standard for the carbon steels for high temperature use and the related standards in foreign countries are shown. The high temperature strength of carbon steels changes according to the trace elements, melting and heat treatment as well as the main compositions of C, Si and Mn. Al and N affect the high temperature strength largely. The characteristics of carbon steels after the heating for hours, the factors controlling the microstructure and high temperature strength, and the measures to improve the high temperature strength of carbon steels are explained. (Kako, I.)

  5. Carbon in high-purity germanium

    International Nuclear Information System (INIS)

    Haller, E.E.; Hansen, W.L.; Luke, P.; McMurray, R.; Jarrett, B.

    1981-10-01

    Using 14 C-spiked pyrolytic graphite-coated quartz crucibles for the growth of nine ultra-pure germanium single crystals, we have determined the carbon content and distribution in these crystals. Using autoradiography, we observe a rapidly decreasing carbon cluster concentration in successively grown crystals. Nuclear radiation detectors made from the crystals measure the betas from the internally decaying 14 C nuclei with close to 100% efficiency. An average value for the total carbon concentration [ 14 C + 12 C] is approx. 2 x 10 14 cm -3 , a value substantially larger than expected from earlier metallurgical studies. Contrary to the most recent measurement, we find the shape of the beta spectrum to agree very well with the statistical shape predicted for allowed transitions

  6. High value carbon materials from PET recycling

    International Nuclear Information System (INIS)

    Parra, J.B.; Ania, C.O.; Arenillas, A.; Rubiera, F.; Pis, J.J.

    2004-01-01

    Poly(ethylene) terephthalate (PET), has become one of the major post-consumer plastic waste. In this work special attention was paid to minimising PET residues and to obtain a high value carbon material. Pyrolysis and subsequent activation of PET from post-consumer soft-drink bottles was performed. Activation was carried out at 925 deg. C under CO 2 atmosphere to different burn-off degrees. Textural characterisation of the samples was carried out by performing N 2 adsorption isotherms at -196 deg. C. The obtained carbons materials were mainly microporous, presenting low meso and macroporosity, and apparent BET surface areas of upto 2500 m 2 g -1 . The capacity of these materials for phenol adsorption and PAHs removal from aqueous solutions was measured and compared with that attained with commercial active carbons. Preliminary tests also showed high hydrogen uptake values, as good as the results obtained with high-tech carbon materials

  7. Ameliorated Austenite Carbon Content Control in Austempered Ductile Irons by Support Vector Regression

    Directory of Open Access Journals (Sweden)

    Chan-Yun Yang

    2013-01-01

    Full Text Available Austempered ductile iron has emerged as a notable material in several engineering fields, including marine applications. The initial austenite carbon content after austenization transform but before austempering process for generating bainite matrix proved critical in controlling the resulted microstructure and thus mechanical properties. In this paper, support vector regression is employed in order to establish a relationship between the initial carbon concentration in the austenite with austenization temperature and alloy contents, thereby exercising improved control in the mechanical properties of the austempered ductile irons. Particularly, the paper emphasizes a methodology tailored to deal with a limited amount of available data with intrinsically contracted and skewed distribution. The collected information from a variety of data sources presents another challenge of highly uncertain variance. The authors present a hybrid model consisting of a procedure of a histogram equalizer and a procedure of a support-vector-machine (SVM- based regression to gain a more robust relationship to respond to the challenges. The results show greatly improved accuracy of the proposed model in comparison to two former established methodologies. The sum squared error of the present model is less than one fifth of that of the two previous models.

  8. Primary Nutritional Content of Bio-Flocs Cultured with Different Organic Carbon Sources and Salinity

    Directory of Open Access Journals (Sweden)

    JULIE EKASARI

    2010-09-01

    Full Text Available Application of bio-flocs technology (BFT in aquaculture offers a solution to avoid environmental impact of high nutrient discharges and to reduce the use of artificial feed. In BFT, excess of nutrients in aquaculture systems are converted into microbial biomass, which can be consumed by the cultured animals as a food source. In this experiment, upconcentrated pond water obtained from the drum filter of a freshwater tilapia farm was used for bio-flocs reactors. Two carbon sources, sugar and glycerol, were used as the first variable, and two different levels of salinity, 0 and 30 ppt, were used as the second variable. Bio-flocs with glycerol as a carbon source had higher total n-6 PUFAs (19.1 ± 2.1 and 22.3 ± 8.6 mg/g DW at 0 and 30 ppt, respectively than that of glucose (4.0 ± 0.1 and 12.6 ± 2.5 mg/g DW at 0 and 30 ppt. However, there was no effect of carbon source or salinity on crude protein, lipid, and total n-3 PUFAs contents of the bio-flocs.

  9. Magneto-carbonization method for production of carbon fiber, and high performance carbon fibers made thereby

    Science.gov (United States)

    Naskar, Amit K.; Ozcan, Soydan; Eberle, Claude C.; Abdallah, Mohamed Gabr; Mackiewicz, Ludtka Gail; Ludtka, Gerard Michael; Paulauskas, Felix Leonard; Rivard, John Daniel Kennedy

    2017-08-08

    Method for the preparation of carbon fiber from fiber precursor, wherein the fiber precursor is subjected to a magnetic field of at least 3 Tesla during a carbonization process. The carbonization process is generally conducted at a temperature of at least 400.degree. C. and less than 2200.degree. C., wherein, in particular embodiments, the carbonization process includes a low temperature carbonization step conducted at a temperature of at least or above 400.degree. C. or 500.degree. C. and less than or up to 1000.degree. C., 1100.degree. C., or 1200.degree. C., followed by a high temperature carbonization step conducted at a temperature of at least or above 1200.degree. C. In particular embodiments, particularly in the case of a polyacrylonitrile (PAN) fiber precursor, the resulting carbon fiber may possess a minimum tensile strength of at least 600 ksi, a tensile modulus of at least 30 Msi, and an ultimate elongation of at least 1.5%.

  10. Remote Sensing of Vegetation Nitrogen Content for Spatially Explicit Carbon and Water Cycle Estimation

    Science.gov (United States)

    Zhang, Y. L.; Miller, J. R.; Chen, J. M.

    2009-05-01

    Foliage nitrogen concentration is a determinant of photosynthetic capacity of leaves, thereby an important input to ecological models for estimating terrestrial carbon and water budgets. Recently, spectrally continuous airborne hyperspectral remote sensing imagery has proven to be useful for retrieving an important related parameter, total chlorophyll content at both leaf and canopy scales. Thus remote sensing of vegetation biochemical parameters has promising potential for improving the prediction of global carbon and water balance patterns. In this research, we explored the feasibility of estimating leaf nitrogen content using hyperspectral remote sensing data for spatially explicit estimation of carbon and water budgets. Multi-year measurements of leaf biochemical contents of seven major boreal forest species were carried out in northeastern Ontario, Canada. The variation of leaf chlorophyll and nitrogen content in response to various growth conditions, and the relationship between them,were investigated. Despite differences in plant type (deciduous and evergreen), leaf age, stand growth conditions and developmental stages, leaf nitrogen content was strongly correlated with leaf chlorophyll content on a mass basis during the active growing season (r2=0.78). With this general correlation, leaf nitrogen content was estimated from leaf chlorophyll content at an accuracy of RMSE=2.2 mg/g, equivalent to 20.5% of the average measured leaf nitrogen content. Based on this correlation and a hyperspectral remote sensing algorithm for leaf chlorophyll content retrieval, the spatial variation of leaf nitrogen content was inferred from the airborne hyperspectral remote sensing imagery acquired by Compact Airborne Spectrographic Imager (CASI). A process-based ecological model Boreal Ecosystem Productivity Simulator (BEPS) was used for estimating terrestrial carbon and water budgets. In contrast to the scenario with leaf nitrogen content assigned as a constant value without

  11. Cubic martensite in high carbon steel

    Science.gov (United States)

    Chen, Yulin; Xiao, Wenlong; Jiao, Kun; Ping, Dehai; Xu, Huibin; Zhao, Xinqing; Wang, Yunzhi

    2018-05-01

    A distinguished structural characteristic of martensite in Fe-C steels is its tetragonality originating from carbon atoms occupying only one set of the three available octahedral interstitial sites in the body-centered-cubic (bcc) Fe lattice. Such a body-centered-tetragonal (bct) structure is believed to be thermodynamically stable because of elastic interactions between the interstitial carbon atoms. For such phase stability, however, there has been a lack of direct experimental evidence despite extensive studies of phase transformations in steels over one century. In this Rapid Communication, we report that the martensite formed in a high carbon Fe-8Ni-1.26C (wt%) steel at room temperature induced by applied stress/strain has actually a bcc rather than a bct crystal structure. This finding not only challenges the existing theories on the stability of bcc vs bct martensite in high carbon steels, but also provides insights into the mechanism for martensitic transformation in ferrous alloys.

  12. GENERALIZATION, FORMULATION AND HEAT CONTENTS OF SIMULATED MSW WITH HIGH MOISTURE CONTENT

    Directory of Open Access Journals (Sweden)

    A. JOHARI

    2012-12-01

    Full Text Available This paper presents a generalization technique for the formulation of simulated municipal solid waste. This technique is used for the elimination of the inconsistency in the municipal solid waste (MSW characteristics due to its heterogeneous nature. The compositions of simulated municipal solid waste were formulated from four major municipal waste streams components in Malaysia namely paper, plastic, food and yard waste. The technique produced four simplified waste generalization categories with composition of paper (19%, plastic (25%, food (27% and green waste (29% respectively. Comparative study was conducted for proximate analysis for the determination of volatile matter, fixed carbon and ash content. Ultimate analysis was performed for carbon and hydrogen content. The heat content for simulated and actual municipal solid waste showed good agreement. The moisture content of the simulated municipal solid waste and actual municipal solid waste were established at 52.34% and 61.71% respectively. Overall results were considered to be representative of the actual compositions of municipal solid waste in Malaysia.

  13. Microstructural investigations of 0.2% carbon content steel

    Science.gov (United States)

    Tollabimazraehno, Sajjad; Hingerl, Kurt

    2011-10-01

    The effect of thermal annealing to get different phases on low carbon steel was investigated. Steel sheets (0.2 wt. % C) of 900 μm thickness were heat treated to produce different structures. All the samples have the same starting point, transformation to coarse austenite at 900 degree Celsius. The nano indentation results revealed that samples have different hadness. By making conventional SEM micrographs, focus ion beam maps, and Electron backscatter diffraction (EBSD) the microstructural development and grain boundary variation of transformed phases martensite, biainte, tempered martensite and different combination of these phases were studied.

  14. Low content of Pt supported on Ni-MoCx/carbon black as a highly durable and active electrocatalyst for methanol oxidation, oxygen reduction and hydrogen evolution reactions in acidic condition

    Science.gov (United States)

    Zhang, Yan; Zang, Jianbing; Jia, Shaopei; Tian, Pengfei; Han, Chan; Wang, Yanhui

    2017-08-01

    Nickel and molybdenum carbide modified carbon black (Ni-MoCx/C) was synthesized by a two-step microwave-assisted deposition/carbonthermal reduction method and characterized by X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. The as-prepared Ni-MoCx/C supported Pt (10 wt%) electrocatalyst (10Pt/Ni-MoCx/C) was synthesized through a microwave-assisted reduction method and 10Pt/Ni-MoCx/C exhibited high electrocatalytic activity for methanol oxidation, oxygen reduction and hydrogen evolution reactions. Results showed that 10Pt/Ni-MoCx/C electrocatalyst had better electrocatalytic activity and stability performance than 20 wt% Pt/C (20Pt/C) electrocatalyst. Among them, the electrochemical surface area of 10Pt/Ni-MoCx/C reached 68.4 m2 g-1, which was higher than that of 20Pt/C (63.2 m2 g-1). The enhanced stability and activity of 10Pt/Ni-MoCx/C electrocatalyst were attributed to: (1) an anchoring effect of Ni and MoCx formed during carbonthermal reduction process; (2) a synergistic effect among Pt, Ni, MoOx and MoCx. These findings indicated that 10Pt/Ni-MoCx/C was a promising electrocatalyst for direct methanol fuel cells.

  15. Carbon nanofibers grafted on activated carbon as an electrode in high-power supercapacitors.

    Science.gov (United States)

    Gryglewicz, Grażyna; Śliwak, Agata; Béguin, François

    2013-08-01

    A hybrid electrode material for high-power supercapacitors was fabricated by grafting carbon nanofibers (CNFs) onto the surface of powdered activated carbon (AC) through catalytic chemical vapor deposition (CCVD). A uniform thin layer of disentangled CNFs with a herringbone structure was deposited on the carbon surface through the decomposition of propane at 450 °C over an AC-supported nickel catalyst. CNF coating was controlled by the reaction time and the nickel content. The superior CNF/AC composite displays excellent electrochemical performance in a 0.5 mol L(-1) solution of K2 SO4 due to its unique structure. At a high scan rate (100 mV s(-1) ) and current loading (20 A g(-1) ), the capacitance values were three- and fourfold higher than those for classical AC/carbon black composites. Owing to this feature, a high energy of 10 Wh kg(-1) was obtained over a wide power range in neutral medium at a voltage of 0.8 V. The significant enhancement of charge propagation is attributed to the presence of herringbone CNFs, which facilitate the diffusion of ions in the electrode and play the role of electronic bridges between AC particles. An in situ coating of AC with short CNFs (below 200 nm) is a very attractive method for producing the next generation of carbon composite materials with a high power performance in supercapacitors working in neutral medium. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Low content of Pt supported on Ni-MoC{sub x}/carbon black as a highly durable and active electrocatalyst for methanol oxidation, oxygen reduction and hydrogen evolution reactions in acidic condition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yan; Zang, Jianbing; Jia, Shaopei; Tian, Pengfei; Han, Chan; Wang, Yanhui, E-mail: diamond_wangyanhui@163.com

    2017-08-01

    Highlights: • Ni-MoC{sub x}/C catalyst support was synthesized by a two-step method. • 10Pt/Ni-MoC{sub x}/C was an active and durable low Pt catalyst for MOR, ORR and HER. • The high stability of 10Pt/Ni-MoC{sub x}/C was ascribed to the anchoring effect of MoC{sub x}. • High activity of 10Pt/Ni-MoC{sub x}/C was due to a synergistic of Pt, Ni, MoO{sub x} and MoC{sub x}. - Abstract: Nickel and molybdenum carbide modified carbon black (Ni-MoC{sub x}/C) was synthesized by a two-step microwave-assisted deposition/carbonthermal reduction method and characterized by X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. The as-prepared Ni-MoC{sub x}/C supported Pt (10 wt%) electrocatalyst (10Pt/Ni-MoC{sub x}/C) was synthesized through a microwave-assisted reduction method and 10Pt/Ni-MoC{sub x}/C exhibited high electrocatalytic activity for methanol oxidation, oxygen reduction and hydrogen evolution reactions. Results showed that 10Pt/Ni-MoC{sub x}/C electrocatalyst had better electrocatalytic activity and stability performance than 20 wt% Pt/C (20Pt/C) electrocatalyst. Among them, the electrochemical surface area of 10Pt/Ni-MoC{sub x}/C reached 68.4 m{sup 2} g{sup −1}, which was higher than that of 20Pt/C (63.2 m{sup 2} g{sup −1}). The enhanced stability and activity of 10Pt/Ni-MoC{sub x}/C electrocatalyst were attributed to: (1) an anchoring effect of Ni and MoC{sub x} formed during carbonthermal reduction process; (2) a synergistic effect among Pt, Ni, MoO{sub x} and MoC{sub x}. These findings indicated that 10Pt/Ni-MoC{sub x}/C was a promising electrocatalyst for direct methanol fuel cells.

  17. Relation between PAH and black carbon contents in size fractions of Norwegian harbor sediments

    International Nuclear Information System (INIS)

    Oen, Amy M.P.; Cornelissen, Gerard; Breedveld, Gijs D.

    2006-01-01

    Distributions of total organic carbon (TOC), black carbon (BC), and polycyclic aromatic hydrocarbons (PAH) were investigated in different particle size fractions for four Norwegian harbor sediments. The total PAH (16-EPA) concentrations ranged from 2 to 113 mg/kg dry weight with the greatest fraction of PAH mass in the sand fraction for three of the four sediments. TOC contents ranged from 0.84% to 14.2% and BC contents from 0.085% to 1.7%. This corresponds to organic carbon (OC = TOC - BC) contents in the range of 0.81-14% and BC:TOC ratios of 1.3-18.1%. PAH isomer ratios suggested that the PAH in all four sediments were of pyrogenic origin. Furthermore, stronger correlations between PAH versus BC (r 2 = 0.85) than versus OC (r 2 = 0.15) were found. For all size fractions and bulk sediments, the PAH-to-BC ratios for the total PAHs were on average 6 ± 3 mg PAH/g BC. These results suggest that PAH distributions were dominated by the presence of BC, rather than OC. As sorption to BC is much stronger than sorption to OC, this may result in significantly lower dissolved concentrations of PAH than expected on the basis of organic carbon partitioning alone. - PAH contents correlated better with black carbon than organic carbon for four Norwegian harbor sediments

  18. High frequency conductivity in carbon nanotubes

    Directory of Open Access Journals (Sweden)

    S. S. Abukari

    2012-12-01

    Full Text Available We report on theoretical analysis of high frequency conductivity in carbon nanotubes. Using the kinetic equation with constant relaxation time, an analytical expression for the complex conductivity is obtained. The real part of the complex conductivity is initially negative at zero frequency and become more negative with increasing frequency, until it reaches a resonance minimum at ω ∼ ωB for metallic zigzag CNs and ω < ωB for armchair CNs. This resonance enhancement is indicative for terahertz gain without the formation of current instabilities induced by negative dc conductivity. We noted that due to the high density of states of conduction electrons in metallic zigzag carbon nanotubes and the specific dispersion law inherent in hexagonal crystalline structure result in a uniquely high frequency conductivity than the corresponding values for metallic armchair carbon nanotubes. We suggest that this phenomenon can be used to suppress current instabilities that are normally associated with a negative dc differential conductivity.

  19. Sulfurized activated carbon for high energy density supercapacitors

    Science.gov (United States)

    Huang, Yunxia; Candelaria, Stephanie L.; Li, Yanwei; Li, Zhimin; Tian, Jianjun; Zhang, Lili; Cao, Guozhong

    2014-04-01

    Sulfurized activated carbon (SAC), made by coating the pore surface with thiophenic sulfur functional groups from the pyrolysis of sulfur flakes, were characterized and tested for supercapacitor applications. From X-ray photoelectron spectroscopy (XPS), the sulfur content in the SAC was found to be 2.7 at%. Electrochemical properties from potentiostatic and galvanostatic measurements, and electrochemical impedance spectroscopy (EIS) were used to evaluate the effect of sulfur on porous carbon electrodes. The SAC electrode exhibits better conductivity, and an obvious increase in specific capacitance that is almost 40% higher than plain activated carbons (ACs) electrode at a high current density of 1.4 A g-1. The proposed mechanism for improved conductivity and capacitive performance due to the sulfur functional groups on ACs will be discussed.

  20. Influence of carbon dioxide content in the biogas to nitrogen oxides emissions

    Directory of Open Access Journals (Sweden)

    Živković Marija A.

    2010-01-01

    Full Text Available Fuels derived from biomass are an alternative solution for the fossil fuel shortage. Usually this kind of fuels is called low calorific value fuels, due to the large proportion of inert components in their composition. The most common is carbon dioxide, and its proportion in biogas can be different, from 10 up to 40%, or even more. The presence of inert component in the composition of biogas causes the problems that are related with flame blow off limits. One of the possibilities for efficient combustion of biogas is the combustion in swirling flow including a pilot burner, aimed to expand the borders of stable combustion. This paper presents an analysis of the influence of the carbon dioxide content to the nitrogen oxides emissions. Laboratory biogas was used with different content of CO2 (10, 20, 30 and 40%. Investigation was carried out for different nominal powers, coefficients of excess air and carbon dioxide content. With increasing content of carbon dioxide, emission of nitrogen oxides was reduced, and this trend was the same throughout the whole range of excess air, carried out through measurements. Still, the influence of carbon dioxide content is significantly less than the influence of excess air. The coefficient of excess air greatly affects the production of radicals which are essential for the formation of nitrogen oxides, O, OH and CH. Also, the results show that the nominal power has no impact on the emission of nitrogen oxides.

  1. A one-step carbonization route towards nitrogen-doped porous carbon hollow spheres with ultrahigh nitrogen content for CO 2 adsorption

    KAUST Repository

    Wang, Yu

    2015-01-01

    © The Royal Society of Chemistry 2015. Nitrogen doped porous carbon hollow spheres (N-PCHSs) with an ultrahigh nitrogen content of 15.9 wt% and a high surface area of 775 m2 g-1 were prepared using Melamine-formaldehyde nanospheres as hard templates and nitrogen sources. The N-PCHSs were completely characterized and were found to exhibit considerable CO2 adsorption performance (4.42 mmol g-1).

  2. Cement content influence in rebar corrosion in carbonated mortars

    Directory of Open Access Journals (Sweden)

    Américo, P. O.

    2003-12-01

    Full Text Available The cement hydration products protect the concrete rebars of the reinforced concrete due to the production of Ca(OH2, NaOH, and KOH that, upon dissolving in the concrete s aqueous phase, generate a pH above 12.5. However, reinforced concrete structures are exposed to pollutant gases, such as, CO2 which upon penetrating the concrete, reacts with the alkaline components, consequently reducing the pH of the aqueous phase causing the loss of passivity by the rebar and as a consequence its corrosion when there is the presence of humidity and oxygen. The objective of the current paper is the analysis of the alkaline reserve influence, measured by the cement content, in the corrosion of rebars employing the polarization resistance technique for determining the corrosion intensity. Results for corrosion intensity of rebars embedded in prismatic mortar test specimens are produced with three cement content levels, with equal water/cement ratio. Cylindrical test specimens were also used for verification of the capillary absorption and the porosity by means of mercury porosymetry The results show that the initiation period is shorter and the corrosion intensity of the rebars is higher when the cement content is lower However, there is also an alteration in the microstructure upon altering the cement content, and far this reason one cannot conclude that the alkaline reserve alone is responsible for these results.

    Los productos de hidratación del cemento protegen las armaduras embebidas en el hormigón debido a la gran cantidad de Ca(OH2, NaOH y KOH disueltos en la fase acuosa del hormigón que proporcionan un pH mayor que 12,5. Sin embargo, las estructuras de hormigón armado están expuestas a los gases contaminantes como el CO2, que al penetrar en el hormigón reacciona con los compuestos alcalinos, se reduce el pH de la fase acuosa y provocan la despasivación de la armadura. Posteriormente, si hay

  3. Determination of Elements and Carbon Content of Stainless Steel Welded Pipeline

    Directory of Open Access Journals (Sweden)

    Pavel Hudeček

    2016-01-01

    Full Text Available Find out defects or problems of welds are not so simple from time to time. Specially, if weld has been made in rough environmental conditions like high temperature, dusty wind and humidity. It is important to assure have good conditions to realize basic step of welding. For welding, have been used welding procedures specification and procedure qualification record. However, difficult conditions, documentations rightness or human errors are always here. Common weld defects like cracks, porosity, lack of penetration and distortion can compromise the strength of the base metal, as well as the integrity of the weld. According of site inspection, there were suspicion of inclusions, leaker or segregation in root of weld. Surface treatment after welding and keep the intervals between single welds to not overheat the pipes. To recognize those suspicions, mechanical testing around weld joint, determination of carbon content and inductively coupled plasma atomic emission spectroscopy will be done.

  4. Can mud (silt and clay) concentration be used to predict soil organic carbon content within seagrass ecosystems?

    KAUST Repository

    Serrano, Oscar; Lavery, P. S.; Duarte, Carlos M.; Kendrick, Gary A.; Calafat, Antoni; York, P.; Steven, Andy; Macreadie, Peter I.

    2016-01-01

    The emerging field of blue carbon science is seeking cost-effective ways to estimate the organic carbon content of soils that are bound by coastal vegetated ecosystems. Organic carbon (C-org) content in terrestrial soils and marine sediments has

  5. Determination of the carbon content of domestic farm produces to estimate offsite C-14 ingestion dose

    International Nuclear Information System (INIS)

    Jung, Y. G.; Kim, M. J.; Lee, G. B.

    2003-01-01

    The carbon content of grains, leafy and root vegetables, and fruits which the Koreans usually eat were calculated to use in the estimation of offsite C-14 ingestion dose. With the data of food intake per day in the Report on 1998 national health and nutrition survey- dietary intake survey, 5 age-group integrate d intake of the 4 farm produce groups were extracted for food items and the amount. Intake percentage in each food group were taken as food weighing factor for the foods. Carbon content was calculated using protein, fat, and carbohydrate content of the foods, and multiplied by the corresponding food weighing factor to derive the content of the food groups. The calculated carbon content of grains, leafy and root vegetables, and fruits were 39.%, 4.2%, 8.0%, and 5.9% respectively. Grains and fruits were not much different from ODCM for carbon content, but vegetables were higher by 0.7%∼4.5%

  6. Oxy-combustion of high water content fuels

    Science.gov (United States)

    Yi, Fei

    As the issues of global warming and the energy crisis arouse extensive concern, more and more research is focused on maximizing energy efficiency and capturing CO2 in power generation. To achieve this, in this research, we propose an unconventional concept of combustion - direct combustion of high water content fuels. Due to the high water content in the fuels, they may not burn under air-fired conditions. Therefore, oxy-combustion is applied. Three applications of this concept in power generation are proposed - direct steam generation for the turbine cycle, staged oxy-combustion with zero flue gas recycle, and oxy-combustion in a low speed diesel-type engine. The proposed processes could provide alternative approaches to directly utilize fuels which intrinsically have high water content. A large amount of energy to remove the water, when the fuels are utilized in a conventional approach, is saved. The properties and difficulty in dewatering high water content fuels (e.g. bioethanol, microalgae and fine coal) are summarized. These fuels include both renewable and fossil fuels. In addition, the technique can also allow for low-cost carbon capture due to oxy-combustion. When renewable fuel is utilized, the whole process can be carbon negative. To validate and evaluate this concept, the research focused on the investigation of the flame stability and characteristics for high water content fuels. My study has demonstrated the feasibility of burning fuels that have been heavily diluted with water in a swirl-stabilized burner. Ethanol and 1-propanol were first tested as the fuels and the flame stability maps were obtained. Flame stability, as characterized by the blow-off limit -- the lowest O2 concentration when a flame could exist under a given oxidizer flow rate, was determined as a function of total oxidizer flow rate, fuel concentration and nozzle type. Furthermore, both the gas temperature contour and the overall ethanol concentration in the droplets along the

  7. Enhancing Phenolic Contents and Antioxidant Potentials of Antidesma thwaitesianum by Supercritical Carbon Dioxide Extraction

    Directory of Open Access Journals (Sweden)

    Warut Poontawee

    2015-01-01

    Full Text Available Supercritical fluid extraction (SFE has increasingly gained attention as an alternative technique for extraction of natural products without leaving toxic residues in extracts. Antidesma thwaitesianum Muell. Arg. (Phyllanthaceae, or ma mao, has been reported to exhibit antioxidant health benefits due to its phenolic constituents. To determine whether SFE technique could impact on phenolic contents and associated antioxidant potentials, ripe fruits of Antidesma thwaitesianum (Phyllanthaceae were extracted using supercritical carbon dioxide (SC-CO2 and conventional solvents (ethanol, water. The results showed that the SC-CO2 extract contained significantly higher yield, total phenolic, flavonoid, and proanthocyanidin contents than those obtained from ethanol and water. It also demonstrated the greatest antioxidant activities as assessed by ABTS radical cation decolorization, DPPH radical scavenging, and ferric reducing antioxidant power (FRAP assays. Further analysis using high-performance liquid chromatography with diode array and mass spectrometry detectors (HPLC-DAD/MSD revealed the presence of catechin as a major phenolic compound of Antidesma thwaitesianum (Phyllanthaceae, with the maximum amount detected in the SC-CO2 extract. These data indicate that SFE technology improves both quantity and quality of Antidesma thwaitesianum fruit extract. The findings added more reliability of using this technique to produce high added value products from this medicinal plant.

  8. Change of deuterium volume content in heavy water during carbon dioxide dissolution in it

    International Nuclear Information System (INIS)

    Efimova, T.I.; Kapitanov, V.F.; Levchenko, G.V.

    1985-01-01

    Carbon dioxide solution density in heavy water at increased temperature and pressure is measured and the influence of carbon dioxide solubility in heavy water on volumetric content of deuterium in it is determined. Investigations were conducted in the temperature range of 303-473 K and pressure range of 3-20 MPa by the autoclave method. Volumetric content of deuterium in heavy water decreases sufficiently with CO 2 dissolved in it in comparison with pure D 2 O under the similar conditions, and this decrease becomes more sufficient with the pressure increase. With the temperature increase the volumetric content of deuterium both for heavy water and for saturated carbon solution in heavy water decreases

  9. Black carbon content in a ponderosa pine forest of eastern Oregon with varying seasons and intervals of prescribed burns

    Science.gov (United States)

    Matosziuk, L.; Hatten, J. A.

    2016-12-01

    Soil carbon represents a significant component of the global carbon cycle. While fire-based disturbance of forest ecosystems acts as a carbon source, the increased temperatures can initiate molecular changes to forest biomass that convert fast cycling organic carbon into more stable forms such as black carbon (BC), a product of incomplete combustion that contains highly-condensed aromatic structures and very low hydrogen and oxygen content. Such forms of carbon can remain in the soil for hundred to thousands of years, effectively creating a long-term carbon sink. The goal of this project is to understand how specific characteristics of prescribed burns, specifically the season of burn and the interval between burns, affect the formation, structure, and retention of these slowly degrading forms of carbon in the soil. Both O-horizon (forest floor) and mineral soil (0-15 cm cores) samples were collected from a season and interval of burn study in Malheur National Forest. The study area is divided into six replicate units, each of which is sub-divided into four treatment areas and a control. Beginning in 1997, each treatment area was subjected to: i) spring burns at five-year intervals, ii) fall burns at five-year intervals, iii) spring burns at 15-year intervals, or iv) fall burns at 15-year intervals. The bulk density, pH, and C/N content of each soil were measured to assess the effect of the burn treatments on the soil. Additionally, the amount and molecular structure of BC in each sample was quantified using the distribution of specific molecular markers (benzene polycarboxylic acids or BPCAs) that are present in the soil following acid digestion.

  10. New sunflower seeds with high contents of phytosterols

    Directory of Open Access Journals (Sweden)

    Velasco Leonardo

    2014-11-01

    Full Text Available Dietary phytosterols have a positive nutritional impact because they contribute to reduce cholesterol levels in blood. Accordingly, foods rich in phytosterols are required in a healthy diet. Vegetable oils are the richest source of phytosterols in the diet, though sunflower oil has lower phytosterol content than other seed oils such as rapeseed and corn. Increasing phytosterol content in sunflower oil requires optimizing first selection procedures. In this way, the development of accurate methods for analyzing phytosterol content in seeds instead of oils has opened up recently the way for large-scale screening for this trait. Large variability for seed phytosterol content has been identified in sunflower germplasm, from which we have developed a line, IASP-18, with about twofold seed phytosterol content than conventional sunflower. The trait is expressed across environments. Genetic studies are underway to characterize its inheritance and assess the feasibility of introgressing genes for high phytosterol content into elite sunflower germplasm.

  11. Electrical properties of multiphase composites based on carbon nanotubes and an optimized clay content

    Science.gov (United States)

    Egiziano, Luigi; Lamberti, Patrizia; Spinelli, Giovanni; Tucci, Vincenzo; Guadagno, Liberata; Vertuccio, Luigi

    2016-05-01

    The experimental results concerning the characterization of a multiphase nanocomposite systems based on epoxy matrix, loaded with different amount of multi-walled carbon nanotubes (MWCNTs) and an optimized Hydrotalcite (HT) clay content (i.e. 0.6 wt%), duly identified by an our previous theoretical study based on Design of Experiment (DoE), are presented. Dynamic-mechanical analysis (DMA) reveal that even the introduction of higher HT loading (up to 1%wt) don't affect significantly the mechanical properties of the nanocomposites while morphological investigations show an effective synergy between clay and carbon nanotubes that leads to peculiar micro/nanostructures that favor the creation of the electrical conductive network inside the insulating resin. An electrical characterization is carried out in terms of DC electrical conductivity, percolation threshold (EPT) and frequency response in the range 10Hz-1MHz. In particular, the measurements of the DC conductivity allow to obtain the typical "percolation" curve also found for classical CNT-polymer mixtures and a value of about 2 S/m for the electrical conductivity is achieved at the highest considered CNTs concentration (i.e. 1 wt%). The results suggest that multiphase nanocomposites obtained incorporating dispersive nanofillers, in addition to the conductive one, may be a valid alternative to the polymer blends, to improve the properties of the polymeric materials thus able to meet high demands, particularly concerning their mechanical and thermal stability and electrical features required in the aircraft engineering.

  12. On the carbide formation in high-carbon stainless steel

    International Nuclear Information System (INIS)

    Mujahid, M.; Qureshi, M.I.

    1996-01-01

    Stainless steels containing high Cr as well as carbon contents in excess of 1.5 weight percent have been developed for applications which require high resistance erosion and environmental corrosion. Formation of carbides is one of important parameters for controlling properties of these materials especially erosion characteristics. Percent work includes the study of different type of carbides which from during the heat treatment of these materials. It has been found that precipitation of secondary carbides and the nature of matrix transformation plays an important role in determining the hardness characteristics of these materials. (author)

  13. High-resolution spatial patterns of Soil Organic Carbon content derived from low-altitude aerial multi-band imagery on the Broadbalk Wheat Experiment at Rothamsted,UK

    DEFF Research Database (Denmark)

    Aldana Jague, Emilien; Goulding, Keith; Heckrath, Goswin Johann

    for monitoring SOC contents in agricultural soils. Remote sensing methods based on multi-spectral images may help map SOC variation in surface soils. Recently, the costs of both Unmanned Aerial Vehicles (UAVs) and multi-spectral cameras have dropped dramatically, opening up the possibility for more widespread...... use of these tools for SOC mapping. Long-term field experiments with distinct SOC contents in adjacent plots, provide a very useful resource for systematically testing remote sensing approaches for measuring SOC. This study focusses on the Broadbalk Wheat Experiment at Rothamsted (UK). The Broadbalk......Soil organic C (SOC) contents in arable landscapes change as a function of management, climate and topography (Johnston et al, 2009). Traditional methods to measure soil C stocks are labour intensive, time consuming and expensive. Consequently, there is a need for developing low-cost methods...

  14. Synthesis of high luminescent carbon nanoparticles

    Science.gov (United States)

    Gvozdyuk, Alina A.; Petrova, Polina S.; Goryacheva, Irina Y.; Sukhorukov, Gleb B.

    2017-03-01

    In this article we report an effective and simple method for synthesis of high luminescent carbon nanodots (CDs). In our work as a carbon source sodium dextran sulfate (DS) was used because it is harmless, its analogs are used in medicine as antithrombotic compounds and blood substitutes after hemorrhage. was used as a substrate We investigated the influence of temperature parameters of hydrothermal synthesis on the photoluminescence (PL) intensity and position of emission maxima. We discovered that the PL intensity can be tuned by changing of synthesis temperature and CD concentration.

  15. Modelling the influence of carbon content on material behavior during forging

    Science.gov (United States)

    Korpała, G.; Ullmann, M.; Graf, M.; Wester, H.; Bouguecha, A.; Awiszus, B.; Behrens, B.-A.; Kawalla, R.

    2017-10-01

    Nowadays the design of single process steps and even of whole process chains is realized by the use of numerical simulation, in particular finite element (FE) based methods. A detailed numerical simulation of hot forging processes requires realistic models, which consider the relevant material-specific parameters to characterize the material behavior, the surface phenomena, the dies as well as models for the machine kinematic. This data exists partial for several materials, but general information on steel groups depending on alloying elements are not available. In order to generate the scientific input data regarding to material modelling, it is necessary to take into account the mathematical functions for deformation behavior as well as recrystallization kinetic, which depends alloying elements, initial microstructure and reheating mode. Besides the material flow characterization, a detailed description of surface changes caused by oxide scale is gaining in importance, as these phenomena affect the material flow and the component quality. Experiments to investigate the influence of only one chemical element on the oxide scale kinetic and the inner structure at high temperatures are still not available. Most data concerning these characteristics is provided for the steel grade C45, so this steel will be used as basis for the tests. In order to identify the effect of the carbon content on the material and oxidation behavior, the steel grades C15 and C60 will be investigated. This paper gives first approaches with regard to the influence of the carbon content on the oxide scale kinetic and the flow stresses combined with the initial microstructure.

  16. High value carbon materials from PET recycling

    Energy Technology Data Exchange (ETDEWEB)

    Parra, J.B.; Ania, C.O.; Arenillas, A.; Rubiera, F.; Pis, J.J

    2004-11-15

    Poly(ethylene) terephthalate (PET), has become one of the major post-consumer plastic waste. In this work special attention was paid to minimising PET residues and to obtain a high value carbon material. Pyrolysis and subsequent activation of PET from post-consumer soft-drink bottles was performed. Activation was carried out at 925 deg. C under CO{sub 2} atmosphere to different burn-off degrees. Textural characterisation of the samples was carried out by performing N{sub 2} adsorption isotherms at -196 deg. C. The obtained carbons materials were mainly microporous, presenting low meso and macroporosity, and apparent BET surface areas of upto 2500 m{sup 2} g{sup -1}. The capacity of these materials for phenol adsorption and PAHs removal from aqueous solutions was measured and compared with that attained with commercial active carbons. Preliminary tests also showed high hydrogen uptake values, as good as the results obtained with high-tech carbon materials.

  17. Risks attributable to water quality changes in shallow potable aquifers from geological carbon sequestration leakage into sediments of variable carbonate content

    DEFF Research Database (Denmark)

    Cahill, Aaron Graham; Jakobsen, Rasmus; Mathiesen, Tina Bay

    2013-01-01

    Denmark including; siliceous, carbonate and clay materials. Sediments were exposed to CO2 and hydro-geochemical effects were observed in order to improve general understanding of trace metal mobility, quantify carbonate influence, assess risks attributable to fresh water resources from a potential leak...... and aid monitoring measurement and verification (MMV) program design. Results demonstrate control of water chemistry by sediment mineralogy and most significantly carbonate content, for which a potential semi-logarithmic relationship with pH and alkalinity was observed. In addition, control of water...... changes in water chemistry with large increases in all major and trace elements coupled to minimal reductions in pH due to high buffering capacity. Silicate dominated sediments exhibited small changes in dissolved major ion concentrations and the greatest reductions in pH, therefore displaying...

  18. A reassessment of carbon content in wood: variation within and between 41 North American species

    International Nuclear Information System (INIS)

    Lamlom, S.H.; Savidge, R.A.

    2003-01-01

    At present, 50% (w/w) carbon is widely promulgated as a generic value for wood; however, the literature yields few data and indicates that very little research has actually been done. C contents in heartwood of forty-one softwood and hardwood species were determined. C in kiln-dried hardwood species ranged from 46.2% to 49.97% (w/w), in conifers from 47.21% to 55.2%. The higher C in conifers agrees with their higher lignin content (∼30%, versus ∼20% for hardwoods). Wood-meal samples drilled from discrete early wood and late wood zones of seven of the forty-one species were also investigated. C contents of early woods were invariably higher than those in corresponding late woods, again in agreement with early wood having higher lignin content. Further investigation was made into freshly harvested wood of some species to determine how much volatile C is present, comparing oven-dried wood meal with wood meal dried at ambient temperature over a desiccant. C contents of oven-dried woods were significantly lower, indicating that all past data on C content in oven-dried or kiln-dried woods may be inaccurate in relation to the true C content of forests. We conclude that C content varies substantially among species as well as within individual trees. Clearly, a 50% generic value is an oversimplification of limited application in relation to global warming and the concept of 'carbon credits'. (author)

  19. Variations and determinants of carbon content in plants: a global synthesis

    Science.gov (United States)

    Ma, Suhui; He, Feng; Tian, Di; Zou, Dongting; Yan, Zhengbing; Yang, Yulong; Zhou, Tiancheng; Huang, Kaiyue; Shen, Haihua; Fang, Jingyun

    2018-02-01

    Plant carbon (C) content is one of the most important plant traits and is critical to the assessment of global C cycle and ecological stoichiometry; however, the global variations in plant C content remain poorly understood. In this study, we conducted a global analysis of the plant C content by synthesizing data from 4318 species to document specific values and their variation of the C content across plant organs and life forms. Plant organ C contents ranged from 45.0 % in reproductive organs to 47.9 % in stems at global scales, which were significantly lower than the widely employed canonical value of 50 %. Plant C content in leaves (global mean of 46.9 %) was higher than that in roots (45.6 %). Across life forms, woody plants exhibited higher C content than herbaceous plants. Conifers, relative to broad-leaved woody species, had higher C content in roots, leaves, and stems. Plant C content tended to show a decrease with increasing latitude. The life form explained more variation of the C content than climate. Our findings suggest that specific C content values of different organs and life forms developed in our study should be incorporated into the estimations of regional and global vegetation biomass C stocks.

  20. Variations and determinants of carbon content in plants: a global synthesis

    Directory of Open Access Journals (Sweden)

    S. Ma

    2018-02-01

    Full Text Available Plant carbon (C content is one of the most important plant traits and is critical to the assessment of global C cycle and ecological stoichiometry; however, the global variations in plant C content remain poorly understood. In this study, we conducted a global analysis of the plant C content by synthesizing data from 4318 species to document specific values and their variation of the C content across plant organs and life forms. Plant organ C contents ranged from 45.0 % in reproductive organs to 47.9 % in stems at global scales, which were significantly lower than the widely employed canonical value of 50 %. Plant C content in leaves (global mean of 46.9 % was higher than that in roots (45.6 %. Across life forms, woody plants exhibited higher C content than herbaceous plants. Conifers, relative to broad-leaved woody species, had higher C content in roots, leaves, and stems. Plant C content tended to show a decrease with increasing latitude. The life form explained more variation of the C content than climate. Our findings suggest that specific C content values of different organs and life forms developed in our study should be incorporated into the estimations of regional and global vegetation biomass C stocks.

  1. The effect of carbon content on mechanical properties, failure and corrosion resistance of deposited chromium metal

    Directory of Open Access Journals (Sweden)

    Леонід Кімович Лещинськiй

    2017-06-01

    Full Text Available It has been shown that if choosing a metal composition for surfacing rolls and rollers of continuous casting machines, both the carbon impact on the mechanical and functional properties and the critical values of the chromium concentration, which determine the corrosion resistance of the metal with regard to electrochemical corrosion theory, should be considered as well. The paper studied the effect of chromium and carbon steel the X5-X12 type on the structure, technological strength, mechanical properties, fracturing resistance and corrosion resistance of the weld metal. The composition of chromium tool steels (deposited metal (X5-used for the rolls of hot rolling mills and (X12-used for continuous casting machines rollers correspond to these values. The impact of carbon on the properties of the deposited metal containing chromium was considered by comparing the data for both types of the deposited metal. It was found that for both types of the deposited metal (X5 and X12, the limiting value of the carbon content, providing an optimal combination of strength, ductility, failure resistance is the same. If the carbon content is more than the limiting value – (0,25% the technological strength and failure resistance of the deposited metal significantly reduce. With increasing carbon content from 0,18 to 0,25% the martensite structure has a mixed morphology – lath and plate. The strength and toughness of the deposited metal grow. Of particular interest is simultaneous increase in the specific work of failure resulted from crack inhibition at the boundary with far less solid and more ductile ferrite. As for the 5% chromium metal, the X12 type composition with 0,25% C, is borderline. With a further increase in the carbon content of the metal both ductility and failure resistance sharply decrease and with 0,40% C the growth rate of fatigue crack increases by almost 1,5 times

  2. Organic carbon content of zooplankton from the nearshore waters of Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, V.R.; Gajbhiye, S.N.; Sayed, F.Y.

    Organic carbon content of zooplankton in the Versova Creek and Thana Creek (polluted areas), off Versova and off Mahim, Bombay, India (relatively unpolluted areas) varied respectively from 21.4-30, 13.2-38.4, 21.6-30 and 25.8-39.6% dry weight...

  3. Properties of carbon composite paper derived from coconut coir as a function of polytetrafluoroethylene content

    Science.gov (United States)

    Destyorini, Fredina; Indriyati; Indayaningsih, Nanik; Prihandoko, Bambang; Zulfia Syahrial, Anne

    2018-03-01

    The carbon composite papers were produced by utilizing carbon materials from coconut coir. In the present work, carbon composite papers (CCP) were prepared by mixing carbon materials in the form of powder and fibre with polymer (ethylene vinyl acetate and polyethylene glycol) in xylene at 100°C. Then, polytetrafluoroethylene (PTFE) with different content was used to treat the surface of CCP. The properties of PTFE-coated CCP were analysed by means of contact angle measurement, tensile testing, porosity, density, and electrical conductivity measurements. As expected, all CCP’s surfaces treated with PTFE were found to be hydrophobic with contact angle >120° and relatively constant during 60 minutes measurement. Furthermore, water contact angle, density, and mechanical properties of CCP generally increase with increasing PTFE content. However, the porosity and electrical conductivity of CCP decrease slightly as the PTFE content increased from 0 wt% to 30 wt%. Based on the observation and analysis, the optimum PTFE content on CCP was 20 %, in which the mechanical properties and hydrophobicity behaviour were improved significantly, but it was only caused a very small drop in porosity and electrical conductivity

  4. The carbon isotope ratios and contents of mineral elements in leaves of Chinese medicinal plants

    International Nuclear Information System (INIS)

    Lin Zhifang; Sun Guchou; Wang Wei

    1989-01-01

    Leaf carbon isotope ratios and 13 kinds of mineral elements were measured on 36 species of common Chinese medicinal plants in a subtropical monsoon forest of Ding Hu Shan in Guangdong Province. The .delta.13C value were from -26.4 to -32.6%, indicating that all of the species belonged the photosynthetic C3 types. The relative lower value of δ13C was observed in the life form of shrubs. The contents of 7 elements (N, P, K, Ca, Na Mg, Si) were dependent upon the species, life form, medicinal function and medicinal part. Herb type medicine and the used medicinal part of leaves or whole plant showed higher levels of above elements than the others. Among the nine groups with different medicinal functions, it was found that more nitrogen was in the leaves of medicinal plants for hemophthisis, hypertension and stomachic troubles, more phosphorus and potassium were in the leaves for cancer and snake bite medicines, but more calcium and magnesium were in the leaves for curing rheumatics. Ferric, aluminium and manganese were the main composition of microelements in leaves. There were higher content of ferric in leaves for hemophthisis medicine, higher zinc in leaves for cold and hypertension medicine, and higher Cup in leaves of stomachic medicine. It was suggested that the pattern of mineral elements in leaves of Chinese medicinal plants reflected the different properties of absorption and accumulation. Some additional effect due to the high content of certain element might be associated with the main function of that medicine

  5. Converting biomass waste into microporous carbon with simultaneously high surface area and carbon purity as advanced electrochemical energy storage materials

    Science.gov (United States)

    Sun, Fei; Wang, Lijie; Peng, Yiting; Gao, Jihui; Pi, Xinxin; Qu, Zhibin; Zhao, Guangbo; Qin, Yukun

    2018-04-01

    Developing carbon materials featuring both high accessible surface area and high structure stability are desirable to boost the performance of constructed electrochemical electrodes and devices. Herein, we report a new type of microporous carbon (MPC) derived from biomass waste based on a simple high-temperature chemical activation procedure. The optimized MPC-900 possesses microporous structure, high surface area, partially graphitic structure, and particularly low impurity content, which are critical features for enhancing carbon-based electrochemical process. The constructed MPC-900 symmetric supercapacitor exhibits high performances in commercial organic electrolyte such as widened voltage window up to 3 V and thereby high energy/power densities (50.95 Wh kg-1 at 0.44 kW kg-1; 25.3 Wh kg-1 at 21.5 kW kg-1). Furthermore, a simple melt infiltration method has been employed to enclose SnO2 nanocrystals onto the carbon matrix of MPC-900 as a high-performance lithium storage material. The obtained SnO2-MPC composite with ultrafine SnO2 nanocrystals delivers high capacities (1115 mAh g-1 at 0.2 A g-1; 402 mAh g-1 at 10 A g-1) and high-rate cycling lifespan of over 2000 cycles. This work not only develops a microporous carbon with high carbon purity and high surface area, but also provides a general platform for combining electrochemically active materials.

  6. Utilisation of high carbon pulverised fuel ash

    OpenAIRE

    Mahmud, Maythem Naji

    2011-01-01

    Coal combustion by-products generated from coal-fired power plant and cause enormous problems for disposal unless a way can be found to utilize these by-products through resource recovery programs. The implementation of air act regulations to reduce NOx emission have resulted millions of tonnes of pulverised fuel ash (PFA) accumulated with high percentage of unburned carbon made it un-saleable for the cement industry. Moreover, alternative fuels such as biomass and import coals were suggested...

  7. Highly selective and stable carbon dioxide uptake in polyindole-derived microporous carbon materials.

    Science.gov (United States)

    Saleh, Muhammad; Tiwari, Jitendra N; Kemp, K Christain; Yousuf, Muhammad; Kim, Kwang S

    2013-05-21

    Adsorption with solid sorbents is considered to be one of the most promising methods for the capture of carbon dioxide (CO₂) from power plant flue gases. In this study, microporous carbon materials used for CO₂ capture were synthesized by the chemical activation of polyindole nanofibers (PIF) at temperatures from 500 to 800 °C using KOH, which resulted in nitrogen (N)-doped carbon materials. The N-doped carbon materials were found to be microporous with an optimal adsorption pore size for CO₂ of 0.6 nm and a maximum (Brunauer-Emmett-Teller) BET surface area of 1185 m(2) g(-1). The PIF activated at 600 °C (PIF6) has a surface area of 527 m(2) g(-1) and a maximum CO₂ storage capacity of 3.2 mmol g(-1) at 25 °C and 1 bar. This high CO₂ uptake is attributed to its highly microporous character and optimum N content. Additionally, PIF6 material displays a high CO₂ uptake at low pressure (1.81 mmol g(-1) at 0.2 bar and 25 °C), which is the best low pressure CO₂ uptake reported for carbon-based materials. The adsorption capacity of this material remained remarkably stable even after 10 cycles. The isosteric heat of adsorption was calculated to be in the range of 42.7-24.1 kJ mol(-1). Besides the excellent CO₂ uptake and stability, PIF6 also exhibits high selectivity values for CO₂ over N₂, CH₄, and H₂ of 58.9, 12.3, and 101.1 at 25 °C, respectively, and these values are significantly higher than reported values.

  8. Total carbon content and humic substances quality in selected subtypes of Cambisols

    Directory of Open Access Journals (Sweden)

    Veronika Petrášová

    2009-01-01

    Full Text Available Cambisols cover an estimated 45% of agricultural soils in the Czech Republic. We aimed our work at stabile forms of organic carbon and humic substances quality in Cambisols under different types of soil management (grassland and arable soil. Object of our study were the following subtypes of Cambisols: Eutric Cambisol (locality Vatín – arable soil, Eutric Cambisol (locality Vatín – grassland, Haplic Cambisol (locality Náměšť n/Oslavou – arable soil, Leptic Cambisol (locality Ocmanice – grassland, Haplic Cambisol (locality Nové Město na Moravě – arable soil, Haplic Cambisol (locality Přemyslov – Tři Kameny – grassland, Arenic Cambisol (locality Pocoucov – arable soil, Dystric Cambisol (locality Sněžné – arable soil, Dystric Cambisol (locality Velká Skrovnice – arable soil, Dystric Cambisol (locality Vojnův Městec – arable soil. Non-destructive spectroscopic methods such as UV-VIS spectroscopy, synchronous fluorescence spectroscopy (SFS and 13C NMR spectroscopy for humic substances (HS quality assessment were used. Total organic carbon (TOC content was determined by oxidimetric titration. Fractionation of HS was made by short fractionation method. Isolation of pure humic ­acids (HA preparation was made according to the standard IHSS method.Results showed that TOC and humus content varied from 2.70 % (grassland to 1.3 % (arable soil. Ave­ra­ge HS sum was 8.4 mg / kg in grassland and 6.4 mg / kg in arable soil. Average HA sum was 3.6 mg / kg in grassland and 3 mg / kg in arable soil. Fulvic acids (FA content was 4.7 mg / kg in grassland and 3.7 mg / kg in arable soil. HS quality was low and very similar for all studied samples. HA/FA ratio low (< 1. HS absorbance in UV-VIS spectral range was low and similar in all studied samples. Higher absorption in this spectral range was closely connected with higher HS content. Also in 2D-synchronous fluorescence scan spectra

  9. Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests

    Science.gov (United States)

    Alan F. Talhelm; Kurt S. Pregitzer; Mark E. Kubiske; Donald R. Zak; Courtney E. Campany; Andrew J. Burton; Richard E. Dickson; George R. Hendrey; J. G. Isebrands; Keith F. Lewin; John Nagy; David F. Karnosky

    2014-01-01

    Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2) and tropospheric ozone (O3) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment...

  10. Late quaternary fluctuations in carbonate and carbonate ion content in the northern Indian ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, S.S.

    -normalized carbonate ion (CO3=*) range from 90 to 125µmol kg-1 in the tropical region of the world oceans with a weight los of 0.3 ± 0.05µg mol -1kg-1 (Broecker and Clark, 201d). Botm water CO3=* concentration bathing the core tops are in the range of 88 to 13 μmolkg-1...

  11. Modelling global change impacts on soil carbon contents of agro-silvo-pastoral Mediterranean systems

    Science.gov (United States)

    Lozano-García, Beatriz; Muñoz-Rojas, Miriam; Parras-Alcántara, Luis

    2016-04-01

    total of 38 sampling points were selected under two management practices and six different land uses: (1) MEOW-dehesa (D); (2) MEOW-dehesa + some pine trees (D+P); (3) MEOW-dehesa + some cork oaks (D+C); (4) MEOW-dehesa + some gall oaks (D + G); (5) MEOW-dehesa after a clarified process and transformed to olive grove but maintaining isolated oaks (OG) and (6) MEOW-dehesa after a clarified process and transformed to cereal pasture with isolated oaks (C). Preliminary results showed a high heterogeneity of SOC contents along the soil profile for different climate and land use scenarios. The methods used here can be easily implemented in other Mediterranean areas with available information on climate, site, soil and land use. Keywords: CarboSOIL model, land use change, climate change, soil depth, dehesa References: Abd-Elmabod, S.K., Muñoz-Rojas, M., Jordán, A., Anaya-Romero, M., De la Rosa, D., 2014. Modelling soil organic carbon stocks along topographic transects under climate change scenarios using CarboSOIL. Geophys. Res. Abstr. vol. 16 EGU2014-295-1, EGU General Assembly.) Álvaro-Fuentes, J., Easter, M., Paustian, K., 2012. Climate change effects on organic carbon storage in agricultural soils of northeastern Spain. Agric. Ecosyst. Environ. 155, 87-94. Corral-Fernández, R., Parras-Alcántara, L., Lozano-García, B. 2013. Stratification ratio of soil organic C, N and C:N in Mediterranean evergreen oak woodland with conventional and organic tillage. Agric. Ecosyst. Environ. 164, 252-259. Francaviglia, R., Coleman, K., Whitmore, A.P., Doro, L., Urracci, G., Rubino, M., Ledda, L., 2012. Changes in soil organic carbon and climate change - application of the RothC model in agrosilvo-pastoral Mediterranean systems. Agric. Syst. 112, 48- 54. IPCC, 2007. Technical summary. In: Climate Change 2007. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change http://www.ipcc.ch/. Lozano-García, B., Parras-Alcántara, L

  12. High nitrogen-containing cotton derived 3D porous carbon frameworks for high-performance supercapacitors

    Science.gov (United States)

    Fan, Li-Zhen; Chen, Tian-Tian; Song, Wei-Li; Li, Xiaogang; Zhang, Shichao

    2015-10-01

    Supercapacitors fabricated by 3D porous carbon frameworks, such as graphene- and carbon nanotube (CNT)-based aerogels, have been highly attractive due to their various advantages. However, their high cost along with insufficient yield has inhibited their large-scale applications. Here we have demonstrated a facile and easily scalable approach for large-scale preparing novel 3D nitrogen-containing porous carbon frameworks using ultralow-cost commercial cotton. Electrochemical performance suggests that the optimal nitrogen-containing cotton-derived carbon frameworks with a high nitrogen content (12.1 mol%) along with low surface area 285 m2 g-1 present high specific capacities of the 308 and 200 F g-1 in KOH electrolyte at current densities of 0.1 and 10 A g-1, respectively, with very limited capacitance loss upon 10,000 cycles in both aqueous and gel electrolytes. Moreover, the electrode exhibits the highest capacitance up to 220 F g-1 at 0.1 A g-1 and excellent flexibility (with negligible capacitance loss under different bending angles) in the polyvinyl alcohol/KOH gel electrolyte. The observed excellent performance competes well with that found in the electrodes of similar 3D frameworks formed by graphene or CNTs. Therefore, the ultralow-cost and simply strategy here demonstrates great potential for scalable producing high-performance carbon-based supercapacitors in the industry.

  13. High nitrogen-containing cotton derived 3D porous carbon frameworks for high-performance supercapacitors

    Science.gov (United States)

    Fan, Li-Zhen; Chen, Tian-Tian; Song, Wei-Li; Li, Xiaogang; Zhang, Shichao

    2015-01-01

    Supercapacitors fabricated by 3D porous carbon frameworks, such as graphene- and carbon nanotube (CNT)-based aerogels, have been highly attractive due to their various advantages. However, their high cost along with insufficient yield has inhibited their large-scale applications. Here we have demonstrated a facile and easily scalable approach for large-scale preparing novel 3D nitrogen-containing porous carbon frameworks using ultralow-cost commercial cotton. Electrochemical performance suggests that the optimal nitrogen-containing cotton-derived carbon frameworks with a high nitrogen content (12.1 mol%) along with low surface area 285 m2 g−1 present high specific capacities of the 308 and 200 F g−1 in KOH electrolyte at current densities of 0.1 and 10 A g−1, respectively, with very limited capacitance loss upon 10,000 cycles in both aqueous and gel electrolytes. Moreover, the electrode exhibits the highest capacitance up to 220 F g−1 at 0.1 A g−1 and excellent flexibility (with negligible capacitance loss under different bending angles) in the polyvinyl alcohol/KOH gel electrolyte. The observed excellent performance competes well with that found in the electrodes of similar 3D frameworks formed by graphene or CNTs. Therefore, the ultralow-cost and simply strategy here demonstrates great potential for scalable producing high-performance carbon-based supercapacitors in the industry. PMID:26472144

  14. Influences of carbon content and coating carbon thickness on properties of amorphous CoSnO3@C composites as anode materials for lithium-ion batteries

    Science.gov (United States)

    Fan, Fuqiang; Fang, Guoqing; Zhang, Ruixue; Xu, Yanhui; Zheng, Junwei; Li, Decheng

    2014-08-01

    A series of core-shell carbon coated amorphous CoSnO3 (CoSnO3@C) with different carbon content are synthesized. Effects of carbon content and coating carbon thickness on the physical and electrochemical performances of the samples were studied in detail. The samples were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), galvanostatic charge-discharge and AC impedance spectroscopy, respectively. The results indicate that controlling the concentration of aqueous glucose solution influences the generation of in-situ carbon layer thickness. The optimal concentration of aqueous glucose solution, carbon content and carbon layer thickness are suggested as 0.25 M, 35.1% and 20 nm, respectively. CoSnO3@C composite prepared under the optimal conditions exhibits excellent cycling performance, whose reversible capacity could reach 491 mA h g-1 after 100 cycles.

  15. Determination of fossil carbon content in Swedish waste fuel by four different methods.

    Science.gov (United States)

    Jones, Frida C; Blomqvist, Evalena W; Bisaillon, Mattias; Lindberg, Daniel K; Hupa, Mikko

    2013-10-01

    This study aimed to determine the content of fossil carbon in waste combusted in Sweden by using four different methods at seven geographically spread combustion plants. In total, the measurement campaign included 42 solid samples, 21 flue gas samples, 3 sorting analyses and 2 investigations using the balance method. The fossil carbon content in the solid samples and in the flue gas samples was determined using (14)C-analysis. From the analyses it was concluded that about a third of the carbon in mixed Swedish waste (municipal solid waste and industrial waste collected at Swedish industry sites) is fossil. The two other methods (the balance method and calculations from sorting analyses), based on assumptions and calculations, gave similar results in the plants in which they were used. Furthermore, the results indicate that the difference between samples containing as much as 80% industrial waste and samples consisting of solely municipal solid waste was not as large as expected. Besides investigating the fossil content of the waste, the project was also established to investigate the usability of various methods. However, it is difficult to directly compare the different methods used in this project because besides the estimation of emitted fossil carbon the methods provide other information, which is valuable to the plant owner. Therefore, the choice of method can also be controlled by factors other than direct determination of the fossil fuel emissions when considering implementation in the combustion plants.

  16. High activity carbon sorbents for mercury capture

    Directory of Open Access Journals (Sweden)

    Stavropoulos George G.

    2006-01-01

    Full Text Available High efficiency activated carbons have been prepared for removing mercury from gas streams. Starting materials used were petroleum coke, lignite, charcoal and olive seed waste, and were chemically activated with KOH. Produced adsorbents were primarily characterized for their porosity by N2 adsorption at 77 K. Their mercury retention capacity was characterized based on the breakthrough curves. Compared with typical commercial carbons, they have exhibited considerably enhanced mercury adsorption capacity. An attempt has been made to correlate mercury entrapment and pore structure. It has been shown that physical surface area is increased during activation in contrast to the mercury adsorption capacity that initially increases and tends to decrease at latter stages. Desorption of active sites may be responsible for this behavior.

  17. High power density carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.; Johnsen, R.; Doyon, J.; Allen, J. [Energy Research Corp., Danbury, CT (United States)

    1996-12-31

    Carbonate fuel cell is a highly efficient and environmentally clean source of power generation. Many organizations worldwide are actively pursuing the development of the technology. Field demonstration of multi-MW size power plant has been initiated in 1996, a step toward commercialization before the turn of the century, Energy Research Corporation (ERC) is planning to introduce a 2.85MW commercial fuel cell power plant with an efficiency of 58%, which is quite attractive for distributed power generation. However, to further expand competitive edge over alternative systems and to achieve wider market penetration, ERC is exploring advanced carbonate fuel cells having significantly higher power densities. A more compact power plant would also stimulate interest in new markets such as ships and submarines where space limitations exist. The activities focused on reducing cell polarization and internal resistance as well as on advanced thin cell components.

  18. Sequestration of organochlorine pesticides in soils of distinct organic carbon content

    International Nuclear Information System (INIS)

    Zhang Na; Yang Yu; Tao Shu; Liu Yan; Shi Kelu

    2011-01-01

    In the present study, five soil samples with organic carbon contents ranging from 0.23% to 7.1% and aged with technical dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) for 15 months were incubated in a sealed chamber to investigate the dynamic changes of the OCP residues. The residues in the soils decreased over the incubation period and finally reached a plateau. Regression analysis showed that degradable fractions of OCPs were negatively correlated with soil organic carbon (SOC) except for α-HCH, while no correlation was found between degradation rate and SOC, which demonstrated that SOC content determines the OCP sequestration fraction in soil. Analysis of the ratio of DDT and its primary metabolites showed that, since it depends on differential sequestration among them, magnitude of (p,p'-DDE + p,p'-DDD)/p,p'-DDT is not a reliable criterion for the identification of new DDT sources. - Research highlights: → Soil organic carbon content determines the OCP sequestration fraction in soil. → Magnitude of (p,p'-DDE + p,p'-DDD)/p,p'-DDT is not a reliable criterion for the identification of new DDT sources. → The more hydrophobic compounds have relatively higher sequestration fractions in soils with SOC contents >2%. → DDD may have higher sorption by soil organic matter than DDE. - The effect of soil organic matter on the sequestration of organochlorine pesticides (HCHs and DDTs) in soils was investigated in an innovative microcosm chamber.

  19. Effect of sulfur content in a sulfur-activated carbon composite on the electrochemical properties of a lithium/sulfur battery

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin-Woo; Kim, Changhyeon; Ryu, Ho-Suk; Cho, Gyu-Bong; Cho, Kwon-Koo; Kim, Ki-Won [School of Materials Science and Engineering, Gyeongsang National University, Jinju (Korea, Republic of); Ahn, Jou-Hyeon [Department of Chemical & Biological Engineering, Gyeongsang National University, Jinju (Korea, Republic of); Wang, Guoxiu [School of Chemistry and Forensic Science, University of Technology Sydney, Sydney, NSW 2007 (Australia); Ahn, Jae-Pyeung [Advanced Analysis Center, Research Planning & Coordination Division, KIST, Seoul (Korea, Republic of); Ahn, Hyo-Jun, E-mail: ahj@gnu.ac.kr [School of Materials Science and Engineering, Gyeongsang National University, Jinju (Korea, Republic of)

    2015-09-15

    Highlights: • The content of sulfur in activated carbon was controlled by solution process. • The sulfur electrode with low sulfur content shows the best performance. • The Li/S battery has capacity of 1360 mAh/g at 1 C and 702 mAh/g at 10 C. - Abstract: The content of sulfur in sulfur/activated carbon composite is controlled from 32.37 wt.% to 55.33 wt.% by a one-step solution-based process. When the sulfur content is limited to 41.21 wt.%, it can be loaded into the pores of an activated carbon matrix in a highly dispersed state. On the contrary, when the sulfur content is 55.33 wt.%, crystalline sulfur can be detected on the surface of the activated carbon matrix. The best electrochemical performance can be obtained for a sulfur electrode with the lowest sulfur content. The sulfur/activated carbon composite with 32.37 wt.% sulfur afforded the highest first discharge capacity of 1360 mAh g{sup −1} at 1 C rate and a large reversible capacity of 702 mAh g{sup −1} at 10 C (16.75 A/g)

  20. High-temperature carbonates in the Stillwater Complex, Montana, USA

    Science.gov (United States)

    Aird, H. M.; Boudreau, A. E.

    2012-12-01

    The processes involved in the petrogenesis of the sulphide-hosted platinum-group-element (PGE) deposits of the Stillwater Complex are controversial, with theories ranging from the purely magmatic to those involving an aqueous fluid. To further constrain these models, we have been examining the trace phase assemblages in rocks away from the ore zones. High-temperature carbonates have been observed in association with sulphide minerals below the platiniferous J-M Reef of the Stillwater Complex. The carbonate assemblage consists of dolomite with exsolved calcite and is found in contact with sulphide minerals: chalcopyrite and pyrrhotite in the Peridotite Zone; and pyrrhotite with pentlandite, pyrite and chalcopyrite in Gabbronorite I of the Lower Banded Series. The minimal silicate alteration and the lack of greenschist minerals in association with the mineral assemblage are consistent with a high-temperature origin for the carbonates. The calcite-dolomite geothermometer [1] yields a minimum formation temperature of ~900°C for the unmixed assemblages. A reaction rim surrounds the carbonate-sulphide assemblages, showing an alteration of the host orthopyroxene to a more Ca-enriched, Fe-depleted composition. This is consistent with diffusive exchange between carbonates and pyroxenes at high temperatures, mediated by an aqueous fluid. The highly variable molar MnO/FeO ratios in both the high-temperature carbonates and their associated altered pyroxene rims also imply their interaction with a fluid. The carbonate assemblages are consistent with Stillwater fluid inclusion studies [2], showing that fluids comprising coexisting Cl-rich brine and carbonic fluid were trapped in pegmatitic quartz at 700-715°C, some of which also contained "accidental" calcite inclusions. The high Cl-content of apatite [3] found below the platiniferous J-M Reef is further evidence that a Cl-rich fluid was migrating through the rocks beneath the Reef. Carbonates have been shown to be stabilized

  1. [Study on the content and carbon isotopic composition of water dissolved inorganic carbon from rivers around Xi'an City].

    Science.gov (United States)

    Guo, Wei; Li, Xiang-Zhong; Liu, Wei-Guo

    2013-04-01

    In this study, the content and isotopic compositions of water dissolved inorganic carbon (DIC) from four typical rivers (Chanhe, Bahe, Laohe and Heihe) around Xi'an City were studied to trace the possible sources of DIC. The results of this study showed that the content of DIC in the four rivers varied from 0.34 to 5.66 mmol x L(-1) with an average value of 1.23 mmol x L(-1). In general, the content of DIC increased from the headstream to the river mouth. The delta13C(DIC) of four rivers ranged from -13.3 per thousand to -7.2 per thousand, with an average value of -10.1 per thousand. The delta13C(DIC) values of river water were all negative (average value of -12.6 per thousand) at the headstream of four rivers, but the delta13C(DIC) values of downstream water were more positive (with an average value of -9.4 per thousand). In addition, delta13C(DIC) of river water showed relatively negative values (the average value of delta13C(DIC) was -10.5 per thousand) near the estuary of the rivers. The variation of the DIC content and its carbon isotope suggested that the DIC sources of the rivers varied from the headstream to the river mouth. The negative delta13C(DIC) value indicated that the DIC may originate from the soil CO2 at the headstream of the rivers. On the other hand, the delta13C(DIC) values of river water at the middle and lower reaches of rivers were more positive, and it showed that soil CO2 produced by respiration of the C4 plants (like corn) and soil carbonates with positive delta13C values may be imported into river water. Meanwhile, the input of pollutants with low delta13C(DIC) values may result in a decrease of delta13C(DIC) values in the rivers. The study indicated that the DIC content and carbon isotope may be used to trace the sources of DIC in rivers around Xi'an City. Our study may provide some basic information for tracing the sources of DIC of rivers in the small watershed area in the Loess Plateau of China.

  2. Kirishites, a new type of natural high-carbon compounds

    Science.gov (United States)

    Marin, Yu. B.; Skublov, G. T.; Yushkin, N. P.

    2010-01-01

    On the right-hand bank of the Volkhov River, in the natural area of tektite-like glasses (Volkhovites), fragments of shungites and slags with bunches of hairlike dark brownish enclosures were found. The filament thickness ranged from 20 to 100 μm, and separate “hairlines” were 3 cm in length. The composition of shungites and “hairlines” was found to be identical, which allowed us to consider the latter as aposhungite carbon formations. The high-carbon hairline structures associated with volkhovites are called kirishites. Kirishites are a new type of high-carbon structures that formed simultaneously with volkhovites in the case of explosion-type delivery of carbon slag and shungite fragments to the daylight surface during Holocene explosive activity. Under sharply reductive conditions, the slags partially melted, the melts were segregated, and carbonaceous-silicate and carbonaceous-ferriferous glasses formed with subsequent decompression-explosive liberation of carbon-supersaturated structures, which were extruded from shungite and slag fragments in the form of a resinoid mass. The “hairlines” were found to be zonal in structure: the central axial zones are composed of high-nitrogen hydrocarbon compounds, and peripheral regions are essentially carbonaceous with a high content of organic-mineral compounds and numerous microanomalies of petrogenic, volatile, rare, and ore elements. Infrared spectroscopy identified in kirishites proteinlike compounds, diagnosed in absorption bands (in cm-1) 600-720 (Amid V), 1200-1300 (Amid III), 1480-1590 (Amid II), 1600-1700 (Amid I), 3000-3800 (vibrations in NH2 and II groups). Gas chromatography, with the possibility of differentiation of left- and right-handed forms, revealed a broad spectrum of amino acids in kirishites, with their total content found to be the absolutely highest record for natural bitumens, an order of magnitude higher than the largest amino acid concentrations ever revealed in fibrous high

  3. Electrorefining of High Carbon Ferromanganese in Molten Salts to Produce Pure Ferromanganese

    Directory of Open Access Journals (Sweden)

    Xiao S. J.

    2017-09-01

    Full Text Available High carbon ferromanganese is used as a starting material to prepare pure ferromanganese by electrorefining in molten salts. High carbon ferromanganese was applied as the anode, molybdenum was the cathode and Ag/AgCl was the reference electrode. The anodic dissolution was investigated by linear polarization in molten NaCl-KCl system. Then potentiostatic electrolysis was carried out to produce pure ferromanganese from high carbon ferromanganese. The cathodic product was determined to be a mixture of manganese and iron by x-ray diffraction (XRD. The content of carbon in the product was analyzed by carbon and sulfur analyzer. The post-electrolysis anode was characterized by scanning electron microscope (SEM. The mechanism of the anode dissolution and the distribution of the main impurity of carbon and silicon after electrolysis were discussed.

  4. Nano-micro carbon spheres anchored on porous carbon derived from dual-biomass as high rate performance supercapacitor electrodes

    Science.gov (United States)

    Liu, Shaobo; Zhao, Yang; Zhang, Baihui; Xia, Hui; Zhou, Jianfei; Xie, Wenke; Li, Hongjian

    2018-03-01

    Hierarchical nano-micro carbon spheres@rice straw-derived porous carbon composites are successfully synthesized by the in situ decoration of the porous carbon with carbon spheres from glucose under the assistance of cetyltrimethyl ammonium bromide micelles and further activated by KOH. The scanning electron microscope images clearly show the carbon spheres disperse homogeneously and orderly onto the surface and in the inner macropores of the porous carbon. The diameter of the carbon spheres varies from 475 nm to 1.6 μm, which can be easily controlled by introducing extra inducing agent. The optimal composites exhibit a large specific surface area (1122 m2 g-1), rich content of oxygen (14.2 wt %), and tunable hierarchical porous structure. When used as supercapacitor electrodes, the novel composites with abundant fruits present a high specific capacitance of 337 F g-1 at 1 A g-1, excellent rate retention of 83% from 1 to 20 A g-1 and a good cycling stability with 96% capacitance retention after 10000 cycles. In this strategy, the thought of shared ion-buffering reservoirs is proposed and the mutual promotion effects between the carbon spheres and porous carbon in the composites are also practically demonstrated to contribute the enhanced electrochemical performances.

  5. An optical method for characterizing carbon content in ceramic pot filters.

    Science.gov (United States)

    Goodwin, J Y; Elmore, A C; Salvinelli, C; Reidmeyer, Mary R

    2017-08-01

    Ceramic pot filter (CPF) technology is a relatively common means of household water treatment in developing areas, and performance characteristics of CPFs have been characterized using production CPFs, experimental CPFs fabricated in research laboratories, and ceramic disks intended to be CPF surrogates. There is evidence that CPF manufacturers do not always fire their products according to best practices and the result is incomplete combustion of the pore forming material and the creation of a carbon core in the final CPFs. Researchers seldom acknowledge the existence of potential existence of carbon cores, and at least one CPF producer has postulated that the carbon may be beneficial in terms of final water quality because of the presence of activated carbon in consumer filters marketed in the Western world. An initial step in characterizing the presence and impact of carbon cores is the characterization of those cores. An optical method which may be more viable to producers relative to off-site laboratory analysis of carbon content has been developed and verified. The use of the optical method is demonstrated via preliminary disinfection and flowrate studies, and the results of these studies indicate that the method may be of use in studying production kiln operation.

  6. Converting loss-on-ignition to organic carbon content in arable topsoil: pitfalls and proposed procedure

    DEFF Research Database (Denmark)

    Jensen, Johannes Lund; Christensen, Bent Tolstrup; Schjønning, Per

    2018-01-01

    Assessments of changes in soil organic carbon (SOC) stocks depend heavily on reliable values of SOC content obtained by automated high‐temperature C analysers. However, historical as well as current research often relies on indirect SOC estimates such as loss‐on‐ignition (LOI). In this study, we...... revisit the conversion of LOI to SOC using soil from two long‐term agricultural field experiments and one arable field with different contents of SOC, clay and particles fractions were isolated from the arable soil. Samples were analysed for texture, LOI (500...

  7. Radiocarbon Content of Dissolved Organic Carbon in the South Indian Ocean

    Science.gov (United States)

    Bercovici, S. K.; McNichol, A. P.; Xu, L.; Hansell, D. A.

    2018-01-01

    We report four profiles of the radiocarbon content of dissolved organic carbon (DOC) spanning the South Indian Ocean (SIO), ranging from the Polar Front (56°S) to the subtropics (29°S). Surface waters held mean DOC Δ14C values of -426 ± 6‰ ( 4,400 14C years) at the Polar Front and DOC Δ14C values of -252 ± 22‰ ( 2,000 14C years) in the subtropics. At depth, Circumpolar Deep Waters held DOC Δ14C values of -491 ± 13‰ ( 5,400 years), while values in Indian Deep Water were more depleted, holding DOC Δ14C values of -503 ± 8‰ ( 5,600 14C years). High-salinity North Atlantic Deep Water intruding into the deep SIO had a distinctly less depleted DOC Δ14C value of -481 ± 8‰ ( 5,100 14C years). We use multiple linear regression to assess the dynamics of DOC Δ14C values in the deep Indian Ocean, finding that their distribution is characteristic of water masses in that region.

  8. Applied Gaussian Process in Optimizing Unburned Carbon Content in Fly Ash for Boiler Combustion

    Directory of Open Access Journals (Sweden)

    Chunlin Wang

    2017-01-01

    Full Text Available Recently, Gaussian Process (GP has attracted generous attention from industry. This article focuses on the application of coal fired boiler combustion and uses GP to design a strategy for reducing Unburned Carbon Content in Fly Ash (UCC-FA which is the most important indicator of boiler combustion efficiency. With getting rid of the complicated physical mechanisms, building a data-driven model as GP is an effective way for the proposed issue. Firstly, GP is used to model the relationship between the UCC-FA and boiler combustion operation parameters. The hyperparameters of GP model are optimized via Genetic Algorithm (GA. Then, served as the objective of another GA framework, the predicted UCC-FA from GP model is utilized in searching the optimal operation plan for the boiler combustion. Based on 670 sets of real data from a high capacity tangentially fired boiler, two GP models with 21 and 13 inputs, respectively, are developed. In the experimental results, the model with 21 inputs provides better prediction performance than that of the other. Choosing the results from 21-input model, the UCC-FA decreases from 2.7% to 1.7% via optimizing some of the operational parameters, which is a reasonable achievement for the boiler combustion.

  9. Application of laser-produced-plasmas to determination of carbon content in steel

    International Nuclear Information System (INIS)

    Ortiz, M.; Aragon, C.; Aguilera, J.A.; Campos, J.

    1994-01-01

    This paper describes an analytical method to determine carbon content in solid and molten steel. It is based on the study of the emission spectrum from a Nd-YAG laser produced plasma. The light emitted from the plasma is focused to the entrance slit of a spectrometer and detected by an OMA III system. For every laser pulse an spectral range of 100 A are recorded. With the use of time-resolved spectroscopy a precision of 1.6% and a detection limit of 65 ppm of carbon content in steel have been obtained. These values are similar to those of other accurate conventional techniques but using optics fiber and laser excitation it is possible to made sample calibrations in hostile environments. Also, as the analysis are made in real time changes in sample composition can be measured without stopping production processes. (Author) 26 refs

  10. Comparative Environmental Life Cycle Assessment of Alternative Uses of Wastewater Carbon Content

    DEFF Research Database (Denmark)

    Kroghsbo, Nena; Nicolaisen, Janna; Wenzel, Henrik

    Alternative scenarios for the wastewater and sludge treatment configurations in urban wastewater treatment were studied with the aim of comparing their environmental aspects. As the reference, a conventional activated sludge treatment was chosen including a primary settling and biogas made from...... the mixed primary and secondary sludge. This reference was then compared to an alternative use of the mixed sludge for the fermentative generation of polyhydroxyalkanoates, PHA and subsequent use of the PHA to substitute polypropylene on the polymer markets. This comparison allows for assessing...... the environmental priorities between biogas and PHA formation from the carbon content of the sludge. Further, the elimination of the primary settling with the aim of using the carbon content of the wastewater for enhanced nitrogen removal in the activated sludge process was studied. This comparison allows...

  11. Application of laser-produced-plasmas to determination of carbon content in steel

    International Nuclear Information System (INIS)

    Ortiz, M.; Aragon, C.; Aguilera, J. A.; Campos, J.

    1994-01-01

    This paper describes an analytical method to determine carbon content in solid and molten steel. It is based on the study of the emission spectrum from a Nd-YAG laser produced plasma. The light emitted from the plasma is focused to the entrance slit of a spectrometer and detected by an OMA III system. For every laser pulse an spectral range of 100 A are recorded. With the use of time-resolved spectroscopy a precision of 1.6 % and a detection limit of 65 ppm of carbon content in steel have been obtained. These values are similar to those of other accurate conventional techniques but using optics fiber and laser excitation it is possible to made sample calibrations in hostile environments. Also, as the analysis are made in real time changes in sample composition can be measured without stopping production processes. (Author) 26 refs

  12. Carbon nanotubes for high-performance logic

    OpenAIRE

    Chen, Zhihong; Wong, H.S. Phillip; Mitra, Subhasish; Bol, Aggeth; Peng, Lianmao; Hills, Gage; Thissen, Nick

    2014-01-01

    Single-wall carbon nanotubes (CNTs) were discovered in 1993 and have been an area of intense research since then. They offer the right dimensions to explore material science and physical chemistry at the nanoscale and are the perfect system to study low-dimensional physics and transport. In the past decade, more attention has been shifted toward making use of this unique nanomaterial in real-world applications. In this article, we focus on potential applications of CNTs in the high-performanc...

  13. In situ one-step synthesis of hierarchical nitrogen-doped porous carbon for high-performance supercapacitors.

    Science.gov (United States)

    Jeon, Ju-Won; Sharma, Ronish; Meduri, Praveen; Arey, Bruce W; Schaef, Herbert T; Lutkenhaus, Jodie L; Lemmon, John P; Thallapally, Praveen K; Nandasiri, Manjula I; McGrail, Benard Peter; Nune, Satish K

    2014-05-28

    A hierarchically structured nitrogen-doped porous carbon is prepared from a nitrogen-containing isoreticular metal-organic framework (IRMOF-3) using a self-sacrificial templating method. IRMOF-3 itself provides the carbon and nitrogen content as well as the porous structure. For high carbonization temperatures (950 °C), the carbonized MOF required no further purification steps, thus eliminating the need for solvents or acid. Nitrogen content and surface area are easily controlled by the carbonization temperature. The nitrogen content decreases from 7 to 3.3 at % as carbonization temperature increases from 600 to 950 °C. There is a distinct trade-off between nitrogen content, porosity, and defects in the carbon structure. Carbonized IRMOFs are evaluated as supercapacitor electrodes. For a carbonization temperature of 950 °C, the nitrogen-doped porous carbon has an exceptionally high capacitance of 239 F g(-1). In comparison, an analogous nitrogen-free carbon bears a low capacitance of 24 F g(-1), demonstrating the importance of nitrogen dopants in the charge storage process. The route is scalable in that multi-gram quantities of nitrogen-doped porous carbons are easily produced.

  14. Influences of carbon content and coating carbon thickness on properties of amorphous CoSnO3@C composites as anode materials for lithium-ion batteries

    International Nuclear Information System (INIS)

    Fan, Fuqiang; Fang, Guoqing; Zhang, Ruixue; Xu, Yanhui; Zheng, Junwei; Li, Decheng

    2014-01-01

    Highlights: • The thickness of carbon coating layers can be successfully controlled through varying molar concentration of aqueous glucose solution. • Coating carbon thickness and carbon content are two important factors on the electrochemical performances of CoSnO3@C. • CoSnO 3 @C under optimized conditions exhibits the optimal balance between the volume buffering effect and reversible capacity. • As-prepared CoSnO 3 @C under optimized conditions shows excellent electrochemical performances, whose reversible capacity could reach 491 mA h g −1 after 100 cycles. - Abstract: A series of core–shell carbon coated amorphous CoSnO 3 (CoSnO 3 @C) with different carbon content are synthesized. Effects of carbon content and coating carbon thickness on the physical and electrochemical performances of the samples were studied in detail. The samples were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), galvanostatic charge–discharge and AC impedance spectroscopy, respectively. The results indicate that controlling the concentration of aqueous glucose solution influences the generation of in-situ carbon layer thickness. The optimal concentration of aqueous glucose solution, carbon content and carbon layer thickness are suggested as 0.25 M, 35.1% and 20 nm, respectively. CoSnO 3 @C composite prepared under the optimal conditions exhibits excellent cycling performance, whose reversible capacity could reach 491 mA h g −1 after 100 cycles

  15. Shedding Light on Filovirus Infection with High-Content Imaging

    Directory of Open Access Journals (Sweden)

    Rekha G. Panchal

    2012-08-01

    Full Text Available Microscopy has been instrumental in the discovery and characterization of microorganisms. Major advances in high-throughput fluorescence microscopy and automated, high-content image analysis tools are paving the way to the systematic and quantitative study of the molecular properties of cellular systems, both at the population and at the single-cell level. High-Content Imaging (HCI has been used to characterize host-virus interactions in genome-wide reverse genetic screens and to identify novel cellular factors implicated in the binding, entry, replication and egress of several pathogenic viruses. Here we present an overview of the most significant applications of HCI in the context of the cell biology of filovirus infection. HCI assays have been recently implemented to quantitatively study filoviruses in cell culture, employing either infectious viruses in a BSL-4 environment or surrogate genetic systems in a BSL-2 environment. These assays are becoming instrumental for small molecule and siRNA screens aimed at the discovery of both cellular therapeutic targets and of compounds with anti-viral properties. We discuss the current practical constraints limiting the implementation of high-throughput biology in a BSL-4 environment, and propose possible solutions to safely perform high-content, high-throughput filovirus infection assays. Finally, we discuss possible novel applications of HCI in the context of filovirus research with particular emphasis on the identification of possible cellular biomarkers of virus infection.

  16. Distribution of cesium-137 in Japanese forest soils. Correlation with the contents of organic carbon

    International Nuclear Information System (INIS)

    Takenaka, Chisato; Onda, Yuichi; Hamajima, Yasunori

    1998-01-01

    The spatial and vertical distributions of 137 Cs in surface soils were surveyed and analyzed then correlated with the contents of organic carbon in the hinoki (Chamaecyparis obtusa Sieb. et Zucc.) plantation forest and secondary forest dominated by red pine (Pinus densiflora Sieb. et Zucc.) in Japan. The spatial variation of 137 Cs activity was observed in the surface soil around the red pine. The average activity of 16 samples around the tree is 42.4 Bq/kg and the standard deviation is 25.9 Bq/kg. This finding indicates the importance in the selection of a sampling site and the number of samples from the surface soils especially around a tree. For the vertical distribution of 137 Cs activity, it was found that the concentration in the surface soil is highest, 149 Bq/kg in the hinoki stand and 101 Bq/kg in the red pine stand, and decreases with depth. The relationship between 137 Cs activity and carbon content in the forest soil was investigated in two undisturbed forest stands. The relations were more precisely expressed using an exponential equation than by a linear equation. From the same forest, similar regression equations were obtained. This indicates that the distribution of 137 Cs could be characterized by the organic carbon content in an undisturbed forest. It is also suggested that the coefficient values in the regression equation help to define the movement of 137 Cs accompanying the decomposition of organic matter

  17. Main Feedbacks Between Oxidizable Carbon Content and Selected Soil Characteristic of Chernozem

    Directory of Open Access Journals (Sweden)

    Vítězslav Vlček

    2015-01-01

    Full Text Available Anthropogenic pressure on our agricultural land is culminating last hundred years, especially after 1948, not only because of only massive application of mineral fertilizers but also because of land consolidation and subsequent accelerated water and wind erosion and use of mechanization. This article focuses on main demonstration of feedbacks especially with oxidizable carbon which can negatively affect soil as a homeostatic system. Oxidizable carbon, as the basis of soil humus, is crucial for maintaining soil fertility and for its resistance to further degradation factors affecting the soil. 35 chernozem sites were selected in South Moravia region. These soils had been probably used for their fertility and availability before the turn of the AD. Unfortunately, their long-term agricultural use has resulted in adverse impact on their quality.This way, shallower forms of erosion were often formed. These erosion forms are omitted for the purposes of our study there. For this work, locations with preserved chernic (i.e. diagnostic horizon, as the horizon with less anthropogenic influence, were selected. Relations between a grain size (clay, silt and sand particles, exchange reaction in soil, sorption capacity, oxidizable carbon content, total nitrogen content and content of selected potentially acceptable elements (Ca, Mg were monitored.

  18. Hydrogen content and density in nanocrystalline carbon films of a predominant diamond character

    International Nuclear Information System (INIS)

    Hoffman, A.; Heiman, A.; Akhvlediani, R.; Lakin, E.; Zolotoyabko, E.; Cyterman, C.

    2003-01-01

    Nanocrystalline carbon films possessing a prevailing diamond or graphite character, depending on substrate temperature, can be deposited from a methane hydrogen mixture by the direct current glow discharge plasma chemical vapor deposition method. While at a temperature of ∼880 deg. C, following the formation of a thin precursor graphitic film, diamond nucleation occurs and a nanodiamond film grows, at higher and lower deposition temperatures the films maintain their graphitic character. In this study the hydrogen content, density and nanocrystalline phase composition of films deposited at various temperatures are investigated. We aim to elucidate the role of hydrogen in nanocrystalline films with a predominant diamond character. Secondary ion mass spectroscopy revealed a considerable increase of the hydrogen concentration in the films that accompanies the growth of nanodiamond. It correlates with near edge x-ray adsorption spectroscopy measurements, that showed an appearance of spectroscopic features associated with the diamond structure, and with a substantial increase of the film density detected by x-ray reflectivity. Electron energy loss spectroscopy showed that nanocrystalline diamond films can be deposited from a CH 4 /H 2 mixture with hydrogen concentration in the 80%-95% range. For a deposition temperature of 880 deg. C, the highest diamond character of the films was found for a hydrogen concentration of 91% of H 2 . The deposition temperature plays an important role in diamond formation, strongly influencing the content of adsorbed hydrogen with an optimum at 880 deg. C. It is suggested that diamond nucleation and growth of the nanodiamond phase is driven by densification of the deposited graphitic films which results in high local compressive stresses. Nanodiamond formation is accompanied by an increase of hydrogen concentration in the films. It is suggested that hydrogen retention is critical for stabilization of nanodiamond crystallites. At lower

  19. High surface area carbon and process for its production

    Energy Technology Data Exchange (ETDEWEB)

    Romanos, Jimmy; Burress, Jacob; Pfeifer, Peter; Rash, Tyler; Shah, Parag; Suppes, Galen

    2016-12-13

    Activated carbon materials and methods of producing and using activated carbon materials are provided. In particular, biomass-derived activated carbon materials and processes of producing the activated carbon materials with prespecified surface areas and pore size distributions are provided. Activated carbon materials with preselected high specific surface areas, porosities, sub-nm (<1 nm) pore volumes, and supra-nm (1-5 nm) pore volumes may be achieved by controlling the degree of carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process.

  20. Porous carbon-coated ZnO nanoparticles derived from low carbon content formic acid-based Zn(II) metal-organic frameworks towards long cycle lithium-ion anode material

    International Nuclear Information System (INIS)

    Gao, Song; Fan, Ruiqing; Li, Bingjiang; Qiang, Liangsheng; Yang, Yulin

    2016-01-01

    Graphical abstract: The nanocomposites constructed from Zn-based MOFs exhibit low carbon content with super-high rate capability and long cycling life. - Highlights: • Novel ZnO@porous carbon matrix nanocomposites are constructed by pyrolysis of Zn-based MOFs. • The nanocomposites constructed with Zn-based MOFs show low carbon content. • The constructed nanocomposites exhibit high energy density, super-high rate capability and long cycling life. - Abstract: Single-C formic acid-based metal-organic frameworks (MOFs) are used to construct novel ZnO@porous carbon matrix nanocomposites by controlled pyrolysis. In the constructed nanocomposites, the porous carbon matrices act as a confined support to prevent agglomeration of the ZnO nanoparticles and create a rapid electron conductive network. Meanwhile, the well-defined, continuous porous structured MOFs provide a large specific surface area, which increases the contact of electrolyte-electrode and improves the penetration of electrolyte. Especially, the reasonable choice of formic acid-based MOFs construct the low carbon content composite, which contribute to the high energy density and long cycle life. The constructed nanocomposites show stable, ultrahigh rate lithium ion storage properties of 650 mAh g −1 at charge/discharge rate of 1 C even after 200 cycles.

  1. High nitrogen availability reduces polyphenol content in Sphagnum peat.

    Science.gov (United States)

    Bragazza, Luca; Freeman, Chris

    2007-05-15

    Peat mosses of the genus Sphagnum constitute the bulk of living and dead biomass in bogs. These plants contain peculiar polyphenols which hamper litter peat decomposition through their inhibitory activity on microbial breakdown. In the light of the increasing availability of biologically active nitrogen in natural ecosystems, litter derived from Sphagnum mosses is an ideal substrate to test the potential effects of increased atmospheric nitrogen deposition on polyphenol content in litter peat. To this aim, we measured total nitrogen and soluble polyphenol concentration in Sphagnum litter peat collected in 11 European bogs under a chronic gradient of atmospheric nitrogen deposition. Our results demonstrate that increasing nitrogen concentration in Sphagnum litter, as a consequence of increased exogenous nitrogen availability, is accompanied by a decreasing concentration of polyphenols. This inverse relationship is consistent with reports that in Sphagnum mosses, polyphenol and protein biosynthesis compete for the same precursor. Our observation of modified Sphagnum litter chemistry under chronic nitrogen eutrophication has implications in the context of the global carbon balance, because a lower content of decay-inhibiting polyphenols would accelerate litter peat decomposition.

  2. Electrochemical Glucose Oxidation Using Glassy Carbon Electrodes Modified with Au-Ag Nanoparticles: Influence of Ag Content

    Directory of Open Access Journals (Sweden)

    Nancy Gabriela García-Morales

    2015-01-01

    Full Text Available This paper describes the application of glassy carbon modified electrodes bearing Aux-Agy nanoparticles to catalyze the electrochemical oxidation of glucose. In particular, the paper shows the influence of the Ag content on this oxidation process. A simple method was applied to prepare the nanoparticles, which were characterized by transmission electron microscopy, Ultraviolet-Visible spectroscopy, X-ray diffraction spectroscopy, and cyclic voltammetry. These nanoparticles were used to modify glassy carbon electrodes. The effectiveness of these electrodes for electrochemical glucose oxidation was evaluated. The modified glassy carbon electrodes are highly sensitive to glucose oxidation in alkaline media, which could be attributed to the presence of Aux-Agy nanoparticles on the electrode surface. The voltammetric results suggest that the glucose oxidation speed is controlled by the glucose diffusion to the electrode surface. These results also show that the catalytic activity of the electrodes depends on the Ag content of the nanoparticles. Best results were obtained for the Au80-Ag20 nanoparticles modified electrode. This electrode could be used for Gluconic acid (GA production.

  3. Electrochemical Determination of Caffeine Content in Ethiopian Coffee Samples Using Lignin Modified Glassy Carbon Electrode

    Directory of Open Access Journals (Sweden)

    Meareg Amare

    2017-01-01

    Full Text Available Lignin film was deposited at the surface of glassy carbon electrode potentiostatically. In contrast to the unmodified glassy carbon electrode, an oxidative peak with an improved current and overpotential for caffeine at modified electrode showed catalytic activity of the modifier towards oxidation of caffeine. Linear dependence of peak current on caffeine concentration in the range 6×10-6 to 100×10-6 mol L−1 with determination coefficient and method detection limit (LoD = 3 s/slope of 0.99925 and 8.37×10-7 mol L−1, respectively, supplemented by recovery results of 93.79–102.17% validated the developed method. An attempt was made to determine the caffeine content of aqueous coffee extracts of Ethiopian coffees grown in four coffee cultivating localities (Wonbera, Wolega, Finoteselam, and Zegie and hence to evaluate the correlation between users preference and caffeine content. In agreement with reported works, caffeine contents (w/w% of 0.164 in Wonbera coffee; 0.134 in Wolega coffee; 0.097 in Finoteselam coffee; and 0.089 in Zegie coffee were detected confirming the applicability of the developed method for determination of caffeine in a complex matrix environment. The result indicated that users’ highest preference for Wonbera and least preference for Zegie cultivated coffees are in agreement with the caffeine content.

  4. Electrochemical Determination of Caffeine Content in Ethiopian Coffee Samples Using Lignin Modified Glassy Carbon Electrode.

    Science.gov (United States)

    Amare, Meareg; Aklog, Senait

    2017-01-01

    Lignin film was deposited at the surface of glassy carbon electrode potentiostatically. In contrast to the unmodified glassy carbon electrode, an oxidative peak with an improved current and overpotential for caffeine at modified electrode showed catalytic activity of the modifier towards oxidation of caffeine. Linear dependence of peak current on caffeine concentration in the range 6 × 10 -6 to 100 × 10 -6  mol L -1 with determination coefficient and method detection limit (LoD = 3 s/slope) of 0.99925 and 8.37 × 10 -7  mol L -1 , respectively, supplemented by recovery results of 93.79-102.17% validated the developed method. An attempt was made to determine the caffeine content of aqueous coffee extracts of Ethiopian coffees grown in four coffee cultivating localities (Wonbera, Wolega, Finoteselam, and Zegie) and hence to evaluate the correlation between users preference and caffeine content. In agreement with reported works, caffeine contents (w/w%) of 0.164 in Wonbera coffee; 0.134 in Wolega coffee; 0.097 in Finoteselam coffee; and 0.089 in Zegie coffee were detected confirming the applicability of the developed method for determination of caffeine in a complex matrix environment. The result indicated that users' highest preference for Wonbera and least preference for Zegie cultivated coffees are in agreement with the caffeine content.

  5. Content

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    secondary levels. In subject matter didactics, the question of content is more developed, but it is still mostly confined to teaching on lower levels. As for higher education didactics, discussions on selection of content are almost non-existent on the programmatic level. Nevertheless, teachers are forced...... curriculum, in higher education, and to generate analytical categories and criteria for selection of content, which can be used for systematic didactical reflection. The larger project also concerns reflection on and clarification of the concept of content, including the relation between content at the level......Aim, content and methods are fundamental categories of both theoretical and practical general didactics. A quick glance in recent pedagogical literature on higher education, however, reveals a strong preoccupation with methods, i.e. how teaching should be organized socially (Biggs & Tang, 2007...

  6. Nitrogen in highly crystalline carbon nanotubes

    International Nuclear Information System (INIS)

    Ducati, C; Koziol, K; Stavrinadis, A; Friedrichs, S; Windle, A H; Midgley, P A

    2006-01-01

    Multiwall carbon nanotubes (MWCNTs) with an unprecedented degree of internal order were synthesised by chemical vapour deposition (CVD) adding a nitrogen-containing compound to the hydrocarbon feedstock. Ferrocene was used as the metal catalyst precursor. The remarkable crystallinity of these nanotubes lies both in the isochirality and in the crystallographic register of their walls, as demonstrated by electron diffraction and high resolution electron microscopy experiments. High resolution transmission electron microscopy analysis shows that the walls of the nanotubes consist of truncated stacked cones, instead of perfect cylinders, with a range of apex angles that appears to be related to the nitrogen concentration in the synthesis process. The structure of armchair, zigzag and chiral nanotubes is modelled and discussed in terms of density of topological defects, providing an interesting comparison with our microscopy experiments. A growth mechanism based on the interplay of base- and tip-growth is proposed to account for our experimental observations

  7. Adsorption of ionizable organic contaminants on multi-walled carbon nanotubes with different oxygen contents

    International Nuclear Information System (INIS)

    Li Xiaona; Zhao Huimin; Quan Xie; Chen Shuo; Zhang Yaobin; Yu Hongtao

    2011-01-01

    Multi-walled carbon nanotubes (MWNTs), which are considered to be promising candidates for the adsorption of toxic organics, are released into aqueous environment with their increasing production and application. In this study, the adsorption behaviors of five structurally related ionizable organic contaminants namely perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorooctanesulfonamide (PFOSA), 2,4-dichlorophenoxyacetic acid (2,4-D) and 4-n-nonylphenol (4-NP) onto MWNTs with different oxygen contents (3.84-22.85%) were investigated. The adsorption kinetics was investigated and simulated with pseudo-second-order model. The adsorption isotherms were found to be fitted with Freundlich model and influenced by both the properties of organic chemicals and the oxygen contents of MWNTs. As adsorption capacity decreases dramatically with the increasing of oxygen contents, the MWNTs with the lowest oxygen contents possess the highest adsorption capacity among four MWNTs. For the MWNTs with the oxygen contents of 3.84%, the adsorption affinity related with hydrophobic interaction and π-electron polarizability decreased in the order of 4-NP > PFOSA > PFOS > 2,4-D > PFOA. Furthermore, the adsorption characters of five contaminants were affected by solution pH and solute pK a considering electrostatic repulse force and hydrogen bonding, which showed the adsorption of MWNTs with lower oxygen content is much sensitive to solution chemistry.

  8. Information management for high content live cell imaging

    Directory of Open Access Journals (Sweden)

    White Michael RH

    2009-07-01

    Full Text Available Abstract Background High content live cell imaging experiments are able to track the cellular localisation of labelled proteins in multiple live cells over a time course. Experiments using high content live cell imaging will generate multiple large datasets that are often stored in an ad-hoc manner. This hinders identification of previously gathered data that may be relevant to current analyses. Whilst solutions exist for managing image data, they are primarily concerned with storage and retrieval of the images themselves and not the data derived from the images. There is therefore a requirement for an information management solution that facilitates the indexing of experimental metadata and results of high content live cell imaging experiments. Results We have designed and implemented a data model and information management solution for the data gathered through high content live cell imaging experiments. Many of the experiments to be stored measure the translocation of fluorescently labelled proteins from cytoplasm to nucleus in individual cells. The functionality of this database has been enhanced by the addition of an algorithm that automatically annotates results of these experiments with the timings of translocations and periods of any oscillatory translocations as they are uploaded to the repository. Testing has shown the algorithm to perform well with a variety of previously unseen data. Conclusion Our repository is a fully functional example of how high throughput imaging data may be effectively indexed and managed to address the requirements of end users. By implementing the automated analysis of experimental results, we have provided a clear impetus for individuals to ensure that their data forms part of that which is stored in the repository. Although focused on imaging, the solution provided is sufficiently generic to be applied to other functional proteomics and genomics experiments. The software is available from: fhttp://code.google.com/p/livecellim/

  9. Enhancement of lipid accumulation by oleaginous yeast through phosphorus limitation under high content of ammonia.

    Science.gov (United States)

    Huang, Xiangfeng; Luo, Huijuan; Mu, Tianshuai; Shen, Yi; Yuan, Ming; Liu, Jia

    2018-04-18

    Low concentrations of acetic acid were used as carbon source to cultivate Cryptococcus curvatus MUCL 29819 for lipid production under high content of ammonia. Phosphorus limitation combined with initial pH regulation (pH = 6) weakened inhibition of free ammonia and promoted lipid accumulation. In batch cultivation, the produced lipid content and yield was 30.3% and 0.92 g/L, higher than those under unlimited condition (18.3% and 0.64 g/L). The content of monounsaturated fatty acid also increased from 37.3% (unlimited condition) to 45.8% (phosphorus-limited condition). During sequencing batch cultivation (SBC), the lipid content reached up to 51.02% under phosphorus-limited condition while only 31.88% under unlimited condition, which can be explained by the higher conversion efficiency of the carbon source to lipid. The total energy consumption including lipid extraction, transesterification and purification was 7.47 and 8.33 GJ under phosphorus-limited and unlimited condition, respectively. Copyright © 2018. Published by Elsevier Ltd.

  10. Carbon and nutrient contents in soils from the Kings River Experimental Watersheds, Sierra Nevada Mountains, California

    Science.gov (United States)

    D.W. Johnson; C.T. Hunsaker; D.W. Glass; B.M. Rau; B.A. Roath

    2011-01-01

    Soil C and nutrient contents were estimated for eight watersheds in two sites (one high elevation, Bull, and one low elevation, Providence) in the Kings River Experimental Watersheds in the western Sierra Nevada Mountains of California. Eighty-seven quantitative pits were dug to measure soil bulk density and total rock content, while three replicate surface samples...

  11. Failure Modes of a Unidirectional Ultra-High-Modulus Carbon-Fiber/Carbon-Matrix Composite

    National Research Council Canada - National Science Library

    Zaldivar, R

    1998-01-01

    The objective of this study was to observe the effects of various microstructural features on the in situ, room-temperature tensile fracture behavior of an ultra-high-modulus, unidirectional carbon/carbon (C/C...

  12. Exploring the multiplicity of soil-human interactions: organic carbon content, agro-forest landscapes and the Italian local communities.

    Science.gov (United States)

    Salvati, Luca; Barone, Pier Matteo; Ferrara, Carlotta

    2015-05-01

    Topsoil organic carbon (TOC) and soil organic carbon (SOC) are fundamental in the carbon cycle influencing soil functions and attributes. Many factors have effects on soil carbon content such as climate, parent material, land topography and the human action including agriculture, which sometimes caused a severe loss in soil carbon content. This has resulted in a significant differentiation in TOC or SOC at the continental scale due to the different territorial and socioeconomic conditions. The present study proposes an exploratory data analysis assessing the relationship between the spatial distribution of soil organic carbon and selected socioeconomic attributes at the local scale in Italy with the aim to provide differentiated responses for a more sustainable use of land. A strengths, weaknesses, opportunities and threats (SWOT) analysis contributed to understand the effectiveness of local communities responses for an adequate comprehension of the role of soil as carbon sink.

  13. Correlation Lengths for Estimating the Large-Scale Carbon and Heat Content of the Southern Ocean

    Science.gov (United States)

    Mazloff, M. R.; Cornuelle, B. D.; Gille, S. T.; Verdy, A.

    2018-02-01

    The spatial correlation scales of oceanic dissolved inorganic carbon, heat content, and carbon and heat exchanges with the atmosphere are estimated from a realistic numerical simulation of the Southern Ocean. Biases in the model are assessed by comparing the simulated sea surface height and temperature scales to those derived from optimally interpolated satellite measurements. While these products do not resolve all ocean scales, they are representative of the climate scale variability we aim to estimate. Results show that constraining the carbon and heat inventory between 35°S and 70°S on time-scales longer than 90 days requires approximately 100 optimally spaced measurement platforms: approximately one platform every 20° longitude by 6° latitude. Carbon flux has slightly longer zonal scales, and requires a coverage of approximately 30° by 6°. Heat flux has much longer scales, and thus a platform distribution of approximately 90° by 10° would be sufficient. Fluxes, however, have significant subseasonal variability. For all fields, and especially fluxes, sustained measurements in time are required to prevent aliasing of the eddy signals into the longer climate scale signals. Our results imply a minimum of 100 biogeochemical-Argo floats are required to monitor the Southern Ocean carbon and heat content and air-sea exchanges on time-scales longer than 90 days. However, an estimate of formal mapping error using the current Argo array implies that in practice even an array of 600 floats (a nominal float density of about 1 every 7° longitude by 3° latitude) will result in nonnegligible uncertainty in estimating climate signals.

  14. The aluminium content of infant formulas remains too high.

    Science.gov (United States)

    Chuchu, Nancy; Patel, Bhavini; Sebastian, Blaise; Exley, Christopher

    2013-10-08

    Recent research published in this journal highlighted the issue of the high content of aluminium in infant formulas. The expectation was that the findings would serve as a catalyst for manufacturers to address a significant problem of these, often necessary, components of infant nutrition. It is critically important that parents and other users have confidence in the safety of infant formulas and that they have reliable information to use in choosing a product with a lower content of aluminium. Herein, we have significantly extended the scope of the previous research and the aluminium content of 30 of the most widely available and often used infant formulas has been measured. Both ready-to-drink milks and milk powders were subjected to microwave digestion in the presence of 15.8 M HNO3 and 30% w/v H2O2 and the aluminium content of the digests was measured by TH GFAAS. Both ready-to-drink milks and milk powders were contaminated with aluminium. The concentration of aluminium across all milk products ranged from ca 100 to 430 μg/L. The concentration of aluminium in two soya-based milk products was 656 and 756 μg/L. The intake of aluminium from non-soya-based infant formulas varied from ca 100 to 300 μg per day. For soya-based milks it could be as high as 700 μg per day. All 30 infant formulas were contaminated with aluminium. There was no clear evidence that subsequent to the problem of aluminium being highlighted in a previous publication in this journal that contamination had been addressed and reduced. It is the opinion of the authors that regulatory and other non-voluntary methods are now required to reduce the aluminium content of infant formulas and thereby protect infants from chronic exposure to dietary aluminium.

  15. Controllable synthesis of carbon nanotubes by changing the Mo content in bimetallic Fe-Mo/MgO catalyst

    International Nuclear Information System (INIS)

    Xu Xiangju; Huang Shaoming; Yang Zhi; Zou Chao; Jiang Junfan; Shang Zhijie

    2011-01-01

    Research highlights: → Increasing the Mo content in the Fe-Mo/MgO catalysts resulted in an increase in wall number, diameter and growth yield of carbon nanotubes. → The Fe interacts with MgO to form complex (MgO) x (FeO) 1-x (0 4 and relative large metal Mo particles can be generated after reduction. → The avalanche-like reduction of MgMoO 4 makes the catalyst particles to be small thus enhances the utilize efficiency of Fe nanoparticles. - Abstract: A series of Fe-Mo/MgO catalysts with different Mo content were prepared by combustion method and used as catalysts for carbon nanotube (CNT) growth. Transmission electron microscopy studies of the nanotubes show that the number of the CNT walls and the CNT diameters increase with the increasing of Mo content in the bimetallic catalyst. The growth yield determined by thermogravimetric analysis also follows the trend: the higher the Mo content, the higher the yield of the CNTs. However, the increase of Mo content leads to the lower degree of graphitization of CNTs. A comparative study on the morphology and catalytic functions of Fe/MgO, Mo/MgO and Fe-Mo/MgO catalysts was carried out by scanning electron microscopy and X-ray diffraction. It is found that the Fe interacts with MgO to form complexes and is then dispersed into the MgO support uniformly, resulting in very small Fe nanoparticles after reduction. The Mo interacts with MgO to form stoichiometry compound MgMoO 4 and relative large metal Mo particles can be generated after reduction. High yield CNTs with small diameter can be generated from Fe-Mo/MgO because the avalanche-like reduction of MgMoO 4 makes the catalyst particles to be small thus enhances the utilize efficiency of Fe nanoparticles.

  16. Engineering properties for high kitchen waste content municipal solid waste

    Directory of Open Access Journals (Sweden)

    Wu Gao

    2015-12-01

    Full Text Available Engineering properties of municipal solid waste (MSW depend largely on the waste's initial composition and degree of degradation. MSWs in developing countries usually have a high kitchen waste content (called HKWC MSW. After comparing and analyzing the laboratory and field test results of physical composition, hydraulic properties, gas generation and gas permeability, and mechanical properties for HKWC MSW and low kitchen waste content MSW (called LKWC MSW, the following findings were obtained: (1 HKWC MSW has a higher initial water content (IWC than LKWC MSW, but the field capacities of decomposed HKWC and LKWC MSWs are similar; (2 the hydraulic conductivity and gas permeability for HKWC MSW are both an order of magnitude smaller than those for LKWC MSW; (3 compared with LKWC MSW, HKWC MSW has a higher landfill gas (LFG generation rate but a shorter duration and a lower potential capacity; (4 the primary compression feature for decomposed HKWC MSW is similar to that of decomposed LKWC MSW, but the compression induced by degradation of HKWC MSW is greater than that of LKWC MSW; and (5 the shear strength of HKWC MSW changes significantly with time and strain. Based on the differences of engineering properties between these two kinds of MSWs, the geo-environmental issues in HKWC MSW landfills were analyzed, including high leachate production, high leachate mounds, low LFG collection efficiency, large settlement and slope stability problem, and corresponding advice for the management and design of HKWC MSW landfills was recommended.

  17. Liquid alternative diesel fuels with high hydrogen content

    Energy Technology Data Exchange (ETDEWEB)

    Hancsok, Jenoe; Varga, Zoltan; Eller, Zoltan; Poelczmann, Gyoergy [Pannonia Univ., Veszprem (Hungary). MOL Dept. of Hydrocarbon Processing; Kasza, Tamas [MOL Hungarian Oil and Gas Plc., Szazhalombatta (Hungary)

    2013-06-01

    Mobility is a keystone of the sustainable development. In the operation of the vehicles as the tools of mobility internal combustion engines, so thus Diesel engines will play a remarkable role in the next decades. Beside fossil fuels - used for power these engines - liquid alternative fuels have higher and higher importance, because of their known advantages. During the presentation the categorization possibilities based on the chronology of their development and application will be presented. The importance of fuels with high hydrogen content will be reviewed. Research and development activity in the field of such kind of fuels will be presented. During this developed catalytic systems and main performance properties of the product will be presented which were obtained in case of biogasoils produced by special hydrocracking of natural triglycerides and in case of necessity followed by isomerization; furthermore in case of synthetic biogasoils obtained by the isomerization hydrocracking of Fischer-Tropsch paraffins produced from biomass based synthesis gas. Excellent combustion properties (cetane number > 65-75), good cold flow properties and reduced harmful material emission due to the high hydrogen content (C{sub n}H{sub 2n+2}) are highlighted. Finally production possibilities of linear and branched paraffins based on lignocelluloses are briefly reviewed. Summarizing it was concluded that liquid hydrocarbons with high isoparaffin content are the most suitable fuels regarding availability, economical and environmental aspects, namely the sustainable development. (orig.)

  18. Stable isotope compositions of organic carbon and contents of organic carbon and nitrogen of lacustrine sediments from sub-arid northern Tanzania

    International Nuclear Information System (INIS)

    Muzuka, A.N.N.

    2006-01-01

    The stable isotope compositions of organic carbon (OC), and contents of OC and nitrogen for four sediment cores recovered from lakes Makat (located in the Ngorongoro Crater), Ndutu and Masek (located in the Serengeti Plains) are used to document sources of organic matter (OM) and climatic changes in sub-arid northern Tanzania during the late Pleistocene-Holocene period. Accelerate mass spectrometer (AMS) 14 C ages on total OM for sediments collected from the Ngorongoro Crater Lake indicate that the sedimentation rate is approximately 17 cm/ka. The δ 13 C values from the 20 cm long core (short core) show a downcore increase, whereas that of 500 cm long core (long core), show two peaks enriched in 13 C and three peaks depleted in 13 C. A general downcore increase in the δ 13 C values for the short core suggests changes in the relative proportion of C 3 and C 4 fraction increasing downcore. Similarly, low and high peaks in the long core suggest changes in the relative proportion of C 3 and C 4 with low values having high proportion of C 3 type of material, probably indicating changes in precipitation and lake levels in the area. Deposition of OM depleted in 13 C took place during periods of high precipitation and high lake levels. Although high content of OC and nitrogen in some core sections are associated with elevated C/N ratio values, diagenetic alteration of isotope signature is unlikely to have caused OC and isotope enrichment in sections having high contents of OC and nitrogen. The OC isotope record from Lake Ndutu shows a general downcore decrease in δ 13 C values and contents of OC and nitrogen. (author)

  19. Climate policy and the optimal extraction of high- and low-carbon fossil fuels

    International Nuclear Information System (INIS)

    Smulders, S.; Van der Werf, E.

    2005-01-01

    We study how restricting CO2 emissions affects resource prices and depletion over time. We use a Hotelling-style model with two non- renewable fossil fuels that differ in their carbon content (e.g. coal and natural gas) and that are imperfect substitutes in final good production. We study both an unexpected constraint and an anticipated constraint. Both shocks induce intertemporal substitution of resource use. When emissions are unexpectedly restricted, it is cost-effective to use high-carbon resources relatively more (less) intensively on impact if this resource is relatively scarce (abundant). If the emission constraint is anticipated, it is cost-effective to use relatively more (less) of the low-carbon input before the constraint becomes binding, in order to conserve relatively more (less) of the high-carbon input for the period when climate policy is active in case the high-carbon resource is relatively scarce (abundant)

  20. Thermal Oxidation of a Carbon Condensate Formed in High-Frequency Carbon and Carbon-Nickel Plasma Flow

    Science.gov (United States)

    Churilov, G. N.; Nikolaev, N. S.; Cherepakhin, A. V.; Dudnik, A. I.; Tomashevich, E. V.; Trenikhin, M. V.; Bulina, N. G.

    2018-02-01

    We have reported on the comparative characteristics of thermal oxidation of a carbon condensate prepared by high-frequency arc evaporation of graphite rods and a rod with a hollow center filled with nickel powder. In the latter case, along with different forms of nanodisperse carbon, nickel particles with nickel core-carbon shell structures are formed. It has been found that the processes of the thermal oxidation of carbon condensates with and without nickel differ significantly. Nickel particles with the carbon shell exhibit catalytic properties with respect to the oxidation of nanosized carbon structures. A noticeable difference between the temperatures of the end of the oxidation process for various carbon nanoparticles and nickel particles with the carbon shell has been established. The study is aimed at investigations of the effect of nickel nanoparticles on the dynamics of carbon condensate oxidation upon heating in the argon-oxygen flow.

  1. Effect of Mo Content on Microstructure and Property of Low-Carbon Bainitic Steels

    Directory of Open Access Journals (Sweden)

    Haijiang Hu

    2016-07-01

    Full Text Available In this work, three low-carbon bainitic steels, with different Mo contents, were designed to investigate the effects of Mo addition on microstructure and mechanical properties. Two-step cooling, i.e., initial accelerated cooling and subsequent slow cooling, was used to obtain the desired bainite microstructure. The results show that the product of strength and elongation first increases and then shows no significant change with increasing Mo. Compared with Mo-free steel, bainite in the Mo-containing steel tends to have a lath-like morphology due to a decrease in the bainitic transformation temperature. More martensite transformation occurs with the increasing Mo, resulting in greater hardness of the steel. Both the strength and elongation of the steel can be enhanced by Mo addition; however, the elongation may decrease with a further increase in Mo. From a practical viewpoint, the content of Mo could be ~0.14 wt. % for the composition design of low-carbon bainitic steels in the present work. To be noted, an optimal scheme may need to consider other situations such as the role of sheet thickness, toughness behavior and so on, which could require changes in the chemistry. Nevertheless, these results provide a reference for the composition design and processing method of low-carbon bainitic steels.

  2. Influence of carbon content on the copper-telluride phase formation and on the resistive switching behavior of carbon alloyed Cu-Te conductive bridge random access memory cells

    International Nuclear Information System (INIS)

    Devulder, Wouter; De Schutter, Bob; Detavernier, Christophe; Opsomer, Karl; Franquet, Alexis; Meersschaut, Johan; Muller, Robert; Van Elshocht, Sven; Jurczak, Malgorzata; Goux, Ludovic; Belmonte, Attilio

    2014-01-01

    In this paper, we investigate the influence of the carbon content on the Cu-Te phase formation and on the resistive switching behavior in carbon alloyed Cu 0.6 Te 0.4 based conductive bridge random access memory (CBRAM) cells. Carbon alloying of copper-tellurium inhibits the crystallization, while attractive switching behavior is preserved when using the material as Cu-supply layer in CBRAM cells. The phase formation is first investigated in a combinatorial way. With increasing carbon content, an enlargement of the temperature window in which the material stays amorphous was observed. Moreover, if crystalline phases are formed, subsequent phase transformations are inhibited. The electrical switching behavior of memory cells with different carbon contents is then investigated by implementing them in 580 μm diameter dot TiN/Cu 0.6 Te 0.4 -C/Al 2 O 3 /Si memory cells. Reliable switching behavior is observed for carbon contents up to 40 at. %, with a resistive window of more than 2 orders of magnitude, whereas for 50 at. % carbon, a higher current in the off state and only a small resistive window are present after repeated cycling. This degradation can be ascribed to the higher thermal and lower drift contribution to the reset operation due to a lower Cu affinity towards the supply layer, leading cycle-after-cycle to an increasing amount of Cu in the switching layer, which contributes to the current. The thermal diffusion of Cu into Al 2 O 3 under annealing also gives an indication of the Cu affinity of the source layer. Time of flight secondary ion mass spectroscopy was used to investigate this migration depth in Al 2 O 3 before and after annealing, showing a higher Cu, Te, and C migration for high carbon contents

  3. Influence of carbon content on the copper-telluride phase formation and on the resistive switching behavior of carbon alloyed Cu-Te conductive bridge random access memory cells

    Science.gov (United States)

    Devulder, Wouter; Opsomer, Karl; Franquet, Alexis; Meersschaut, Johan; Belmonte, Attilio; Muller, Robert; De Schutter, Bob; Van Elshocht, Sven; Jurczak, Malgorzata; Goux, Ludovic; Detavernier, Christophe

    2014-02-01

    In this paper, we investigate the influence of the carbon content on the Cu-Te phase formation and on the resistive switching behavior in carbon alloyed Cu0.6Te0.4 based conductive bridge random access memory (CBRAM) cells. Carbon alloying of copper-tellurium inhibits the crystallization, while attractive switching behavior is preserved when using the material as Cu-supply layer in CBRAM cells. The phase formation is first investigated in a combinatorial way. With increasing carbon content, an enlargement of the temperature window in which the material stays amorphous was observed. Moreover, if crystalline phases are formed, subsequent phase transformations are inhibited. The electrical switching behavior of memory cells with different carbon contents is then investigated by implementing them in 580 μm diameter dot TiN/Cu0.6Te0.4-C/Al2O3/Si memory cells. Reliable switching behavior is observed for carbon contents up to 40 at. %, with a resistive window of more than 2 orders of magnitude, whereas for 50 at. % carbon, a higher current in the off state and only a small resistive window are present after repeated cycling. This degradation can be ascribed to the higher thermal and lower drift contribution to the reset operation due to a lower Cu affinity towards the supply layer, leading cycle-after-cycle to an increasing amount of Cu in the switching layer, which contributes to the current. The thermal diffusion of Cu into Al2O3 under annealing also gives an indication of the Cu affinity of the source layer. Time of flight secondary ion mass spectroscopy was used to investigate this migration depth in Al2O3 before and after annealing, showing a higher Cu, Te, and C migration for high carbon contents.

  4. Highly thermal conductive carbon fiber/boron carbide composite material

    International Nuclear Information System (INIS)

    Chiba, Akio; Suzuki, Yasutaka; Goto, Sumitaka; Saito, Yukio; Jinbo, Ryutaro; Ogiwara, Norio; Saido, Masahiro.

    1996-01-01

    In a composite member for use in walls of a thermonuclear reactor, if carbon fibers and boron carbide are mixed, since they are brought into contact with each other directly, boron is reacted with the carbon fibers to form boron carbide to lower thermal conductivity of the carbon fibers. Then, in the present invention, graphite or amorphous carbon is filled between the carbon fibers to provide a fiber bundle of not less than 500 carbon fibers. Further, the surface of the fiber bundle is coated with graphite or amorphous carbon to suppress diffusion or solid solubilization of boron to carbon fibers or reaction of them. Then, lowering of thermal conductivity of the carbon fibers is prevented, as well as the mixing amount of the carbon fiber bundles with boron carbide, a sintering temperature and orientation of carbon fiber bundles are optimized to provide a highly thermal conductive carbon fiber/boron carbide composite material. In addition, carbide or boride type short fibers, spherical graphite, and amorphous carbon are mixed in the boron carbide to prevent development of cracks. Diffusion or solid solubilization of boron to carbon fibers is reduced or reaction of them if the carbon fibers are bundled. (N.H.)

  5. Coupled Land Surface-Subsurface Hydrogeophysical Inverse Modeling to Estimate Soil Organic Carbon Content in an Arctic Tundra

    Science.gov (United States)

    Tran, A. P.; Dafflon, B.; Hubbard, S.

    2017-12-01

    Soil organic carbon (SOC) is crucial for predicting carbon climate feedbacks in the vulnerable organic-rich Arctic region. However, it is challenging to achieve this property due to the general limitations of conventional core sampling and analysis methods. In this study, we develop an inversion scheme that uses single or multiple datasets, including soil liquid water content, temperature and ERT data, to estimate the vertical profile of SOC content. Our approach relies on the fact that SOC content strongly influences soil hydrological-thermal parameters, and therefore, indirectly controls the spatiotemporal dynamics of soil liquid water content, temperature and their correlated electrical resistivity. The scheme includes several advantages. First, this is the first time SOC content is estimated by using a coupled hydrogeophysical inversion. Second, by using the Community Land Model, we can account for the land surface dynamics (evapotranspiration, snow accumulation and melting) and ice/liquid phase transition. Third, we combine a deterministic and an adaptive Markov chain Monte Carlo optimization algorithm to better estimate the posterior distributions of desired model parameters. Finally, the simulated subsurface variables are explicitly linked to soil electrical resistivity via petrophysical and geophysical models. We validate the developed scheme using synthetic experiments. The results show that compared to inversion of single dataset, joint inversion of these datasets significantly reduces parameter uncertainty. The joint inversion approach is able to estimate SOC content within the shallow active layer with high reliability. Next, we apply the scheme to estimate OC content along an intensive ERT transect in Barrow, Alaska using multiple datasets acquired in the 2013-2015 period. The preliminary results show a good agreement between modeled and measured soil temperature, thaw layer thickness and electrical resistivity. The accuracy of estimated SOC content

  6. Auto Detection For High Level Water Content For Oil Well

    Science.gov (United States)

    Janier, Josefina Barnachea; Jumaludin, Zainul Arifin B.

    2010-06-01

    Auto detection of high level water content for oil well is a system that measures the percentage of water in crude oil. This paper aims to discuss an auto detection system for measuring the content of water level in crude oil which is applicable for offshore and onshore oil operations. Data regarding water level content from wells can be determined by using automation thus, well with high water level can be determined immediately whether to be closed or not from operations. Theoretically the system measures the percentage of two- fluid mixture where the fluids have different electrical conductivities which are water and crude oil. The system made use of grid sensor which is a grid pattern like of horizontal and vertical wires. When water occupies the space at the intersection of vertical and horizontal wires, an electrical signal is detected which proved that water completed the circuit path in the system. The electrical signals are counted whereas the percentage of water is determined from the total electrical signals detected over electrical signals provided. Simulation of the system using the MultiSIM showed that the system provided the desired result.

  7. The effect of type-B carbonate content on the elasticity of fluorapatite

    Science.gov (United States)

    Cámara, Fernando; Curetti, Nadia; Benna, Piera; Abdu, Yassir A.; Hawthorne, Frank C.; Ferraris, Cristiano

    2018-03-01

    The mechanical behavior of carbonate-bearing fluorapatite (CFAP) (with up to 5.5 wt% CO3) was investigated at high pressure up to 7 GPa. The incorporation of carbonate in CFAP samples was investigated by FTIR spectroscopy. The chemical formulae and cell parameters are Ca4.90Fe0.04 (PO4)2.87 (CO3)0.13 F1.23 and a = 9.3527(1), c = 6.8752(1) Å, V = 520.83(1) Å3 for the FOW CFAP (Fowey Consols area, UK), and Ca4.97Sr0.03 (PO4)2.55 (CO3)0.45 F1.42 and a = 9.3330(1), c = 6.8984(1) Å, V = 520.38(1) Å3 for the FRA CFAP (Framont region, France). Preliminary characterization at ambient conditions was done by single-crystal X-ray diffraction study. The structure refinements, in space group P63/m, confirm a type-B substitution of the phosphate (PO4)3- group by the carbonate ion (CO3)2-. The site occupancies for the C atom are 0.04 for FOW and 0.11 for FRA CFAP, in quite good agreement with the 1.6 and 5.5 wt% CO3 amount obtained by analytical methods. Single-crystal high-pressure XRD study on the two type-B CFAP samples was performed. The FOW and FRA crystals were mounted concurrently in a ETH-type DAC and cell parameters were determined at 26 different pressures up to 6.86 GPa at room T. The variation with pressure of the unit-cell parameters and volume shows no discontinuity that could be related to any possible phase transition in the P range investigated. The linear compressibility coefficients are β a = 3.63 × 10-3 GPa-1 and β c = 2.47 × 10-3 GPa-1 for FOW, and β a = 3.67 × 10-3 GPa-1 and β c = 2.65 × 10-3 GPa-1 for FRA, giving an axial anisotropy of β a :β c = 1.47:1 and 1.38:1, respectively. The P-V data were fitted by a second-order Birch-Murnaghan EoS and the resulting BM2-EoS coefficients are V 0 = 519.81(7) Å3, K T0 = 92.1(3) GPa for FOW, and V 0 = 518.95(9) Å3, K T0 = 89.1(4) GPa for FRA CFAP. The results obtained indicate that a 5.5 wt% CO3 content (type-B) reduces the isothermal bulk modulus by about 9%.

  8. Influence of the Mg-content on ESR-signals in synthetic calcium carbonate

    International Nuclear Information System (INIS)

    Barabas, M.; Bach, A.; Mudelsee, M.; Mangini, A.

    1989-01-01

    Carbonate crystals doped with various concentrations of Mg 2+ -ions have been grown by a gel-diffusion method. An increase of the Mg/Ca-ratio to more than about 1 caused a phase change in the crystal lattice from calcite to aragonite. The properties of the ESR-signals of the synthetic carbonates were studied and compared with natural marine carbonates. The following results were derived: (a) In the presence of Mg 2+ -ions the synthetic carbonates display the same ESR-signals as natural calcites of marine origin with similar properties (thermal stability, radiation sensitivity). (b) The saturation value of the signal at g=2.0006 in synthetic calcites was found to be strongly related with the Mg-content in the crystals. (c) The signal at g=2.0036 (axial symmetry) which is present in calcite was not influenced by the Mg-concentration. Its saturation value decreases when the crystal phase changed from calcite to aragonite and in complement the signal at g=2.0031 appeared. (d) The signals at g=2.0057 and g=2.0031 are most probably not of organic origin. (author)

  9. Mapping soil organic carbon content and composition across Australia to assess vulnerability to climate change

    Science.gov (United States)

    Viscarra Rossel, R. A.

    2015-12-01

    We can effectively monitor soil condition—and develop sound policies to offset the emissions of greenhouse gases—only with accurate data from which to define baselines. Currently, estimates of soil organic C for countries or continents are either unavailable or largely uncertain because they are derived from sparse data, with large gaps over many areas of the Earth. Here, we derive spatially explicit estimates, and their uncertainty, of the distribution and stock of organic C content and composition in the soil of Australia. The composition of soil organic C may be characterized by chemical separation or physical fractionation based on either particle size or particle density (Skjemstad et al., 2004; Gregorich et al., 2006; Kelleher&Simpson, 2006; Zimmermann et al., 2007). In Australia, for example, Skjemstad et al. (2004) used physical separation of soil samples into 50-2000 and solid-state 13C nuclear magnetic resonance (NMR) spectroscopy, giving the three OC pools, particulate organic carbon (POC), humic organic carbon (HOC) and resistant organic carbon (ROC; charcoal or char-carbon). We assembled and harmonized data from several sources to produce the most comprehensive set of data on the current stock of organic C in soil of the continent. Using them, we have produced a fine spatial resolution baseline map of organic C, POC, HOC and ROC at the continental scale. In this presentation I will describe how we made the maps and how we use them to assess the vulnerability of soil organic C to for instance climate change.

  10. The hydrogen and oxygen content of self-supporting carbon foils prepared by dc glow discharge in ethylene

    International Nuclear Information System (INIS)

    Tait, N.R.S.; Tolfree, D.W.L.; John, P.; Odeh, I.M.; Thomas, M.J.K.; Tricker, M.J.; Wilson, J.J.B.; England, J.B.A.; Newton, D.

    1980-01-01

    The hydrogen and oxygen content of self-supporting carbon films produced by dc glow discharge have been determined using a precise method involving the elastic scattering of 25 MeV α-particles. The number of carbon-hydrogen bonds has been determined for similar samples using infrared spectroscopy. The results are compared with those for samples made by the carbon arc process. Assuming that the glow discharge carbon contains graphitic regions surrounded by amorphous tetrahedrally bonded material to which hydrogen can attach, a simple estimate is made of the relative numbers of carbon atoms in the two forms. (orig.)

  11. Corrosion Performance of Inconel 625 in High Sulphate Content

    Science.gov (United States)

    Ismail, Azzura

    2016-05-01

    Inconel 625 (UNS N06625) is a type of nickel-chromium-molybdenum alloy with excellent corrosion resistance in a wide range of corrosive media, being especially resistant to pitting and crevice corrosion. However, in aggressive environment, Inconel 625 will suffer corrosion attack like other metals. This research compared the corrosion performance of Inconel 625 when exposed to higher sulphate content compared to real seawater. The results reveal that Inconel 625 is excellent in resist the corrosion attack in seawater. However, at increasing temperature, the corrosion resistance of this metal decrease. The performance is same in seawater with high sulphate content at increasing temperature. It can be concluded that sulphate promote perforation on Inconel 625 and become aggressive agents that accelerate the corrosion attack.

  12. Organic carbon determination in histosols and soil horizons with high organic matter content from Brazil Determinação do carbono orgânico em organossolos e solos com horizontes com elevado conteúdo de matéria orgânica

    Directory of Open Access Journals (Sweden)

    Marcos Gervasio Pereira

    2006-04-01

    Full Text Available Soil taxonomy systems distinguish mineral soils from organic soils based on the amount of soil organic carbon. Procedures adopted in soil surveys for organic carbon measurement are therefore of major importance to classify the soils, and to correlate their properties with data from other studies. To evaluate different methods for measuring organic carbon and organic matter content in Histosols and soils with histic horizons, from different regions of Brazil, 53 soil samples were comparatively analyzed by the methods of Walkley & Black (modified, Embrapa, Yeomans & Bremner, modified Yeomans & Bremner, muffle furnace, and CHN. The modified Walkley & Black (C-W & B md and the combustion of organic matter in the muffle furnace (OM-Muffle were the most suitable for the samples with high organic carbon content. Based on regression analysis data, the OM-muffle may be estimated from C-W & B md by applying a factor that ranges from 2.00 to 2.19 with 95% of probability. The factor 2.10, the average value, is suggested to convert results obtained by these methods.Sistemas taxonômicos distinguem horizontes e/ou camadas minerais das orgânicas baseando-se na quantidade de carbono orgânico. Assim, o procedimento adotado em pesquisas para a quantificação do conteúdo de carbono orgânico é de grande importância para a classificação das terras e correlacionar as suas propriedades com dados de outros estudos. Com o objetivo de avaliar os diferentes métodos para medir o conteúdo de carbono orgânico e de matéria orgânica em Organossolo e solos com elevados teores de matéria orgânica, de diferentes regiões do Brasil, cinqüenta e três amostras de terra foram comparativamente analisadas pelos métodos de Walkley & Black (modificado, Embrapa, Yeomans & Bremner, Yeomans & Bremner modificado, forno mufla, e CHN. O método Walkley & Black modificado (C-W & B md e a combustão de matéria orgânica no forno mufla (MO-Mufla revelaram-se mais satisfat

  13. Effect of carbon content on the microstructure and creep properties of a 3rd generation single crystal nickel-base superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.W.; Liu, T. [Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Wang, L., E-mail: wangli@imr.ac.cn [Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Liu, X.G.; Lou, L.H. [Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Zhang, J. [Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2015-07-15

    Effect of carbon content on the microstructure and creep properties of a 3rd generation single crystal nickel-base superalloy has been investigated by the scanning electron microscope, X-ray computed tomography and electron probe microanalyzer. With the increase of the carbon content, MC carbides evolve from octahedral to well-developed dendrite, which promotes the formation of microporosity. Moreover, the volume fraction of porosity increases in the experimental alloys after solution heat treatment. As a result, the increase in the size of MC carbides and the porosity has a detrimental effect on the low temperature and high stress creep behavior of the alloys. The specimen crept at 850 °C and 586 MPa with the carbon content of 430 ppm shows the shortest rupture life due to the largest primary creep strain. However, the creep behavior of the alloy at 1120 °C and 140 MPa gets better as the carbon content increases from 88 to 430 ppm. TCP phase is observed near the fracture surfaces of the alloys, which explores as a potential cause for the creep rupture. However, the formation of TCP phase is effectively suppressed for decreasing segregation of the alloying elements, which results in the improvement of the creep life in the alloy with 430 ppm carbon at 1120 °C and 140 MPa.

  14. High-content profiling of cell responsiveness to graded substrates based on combinyatorially variant polymers.

    Science.gov (United States)

    Liu, Er; Treiser, Matthew D; Patel, Hiral; Sung, Hak-Joon; Roskov, Kristen E; Kohn, Joachim; Becker, Matthew L; Moghe, Prabhas V

    2009-08-01

    We have developed a novel approach combining high information and high throughput analysis to characterize cell adhesive responses to biomaterial substrates possessing gradients in surface topography. These gradients were fabricated by subjecting thin film blends of tyrosine-derived polycarbonates, i.e. poly(DTE carbonate) and poly(DTO carbonate) to a gradient temperature annealing protocol. Saos-2 cells engineered with a green fluorescent protein (GFP) reporter for farnesylation (GFP-f) were cultured on the gradient substrates to assess the effects of nanoscale surface topology and roughness that arise during the phase separation process on cell attachment and adhesion strength. The high throughput imaging approach allowed us to rapidly identify the "global" and "high content" structure-property relationships between cell adhesion and biomaterial properties such as polymer chemistry and topography. This study found that cell attachment and spreading increased monotonically with DTE content and were significantly elevated at the position with intermediate regions corresponding to the highest "gradient" of surface roughness, while GFP-f farnesylation intensity descriptors were sensitively altered by surface roughness, even in cells with comparable levels of spreading.

  15. Carbon Dioxide Mitigation Benefit of High-Speed Railway in Terms of Carbon Tax

    Directory of Open Access Journals (Sweden)

    Fu Yanbing

    2013-01-01

    Full Text Available This paper calculates the carbon dioxide mitigation benefit of high-speed railway based on the carbon dioxide tax policy. We define the carbon dioxide emission system boundary for high-speed railway in its whole life cycle and estimate the life cycle carbon dioxide inventories during its construction, application, and recovery stages. And then we establish a theoretical model to calculate the life cycle carbon dioxide mitigation quantity for high-speed railway when compared with road transport and then calculate its carbon dioxide mitigation benefit. The numerical example shows that the carbon dioxide mitigation benefit of high-speed railway is better than that of road transport from the whole life cycle perspective.

  16. High-strength porous carbon and its multifunctional applications

    Science.gov (United States)

    Wojtowicz, Marek A; Rubenstein, Eric P; Serio, Michael A; Cosgrove, Joseph E

    2013-12-31

    High-strength porous carbon and a method of its manufacture are described for multifunctional applications, such as ballistic protection, structural components, ultracapacitor electrodes, gas storage, and radiation shielding. The carbon is produced from a polymer precursor via carbonization, and optionally by surface activation and post-treatment.

  17. Robust, Reliable Low Emission Gas Turbine Combustion of High Hydrogen Content Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Wooldridge, Margaret Stacy [Univ. of Michigan, Ann Arbor, MI (United States); Im, Hong Geum [Univ. of Michigan, Ann Arbor, MI (United States)

    2016-12-16

    The effects of high hydrogen content fuels were studied using experimental, computational and theoretical approaches to understand the effects of mixture and state conditions on the ignition behavior of the fuels. A rapid compression facility (RCF) was used to measure the ignition delay time of hydrogen and carbon monoxide mixtures. The data were combined with results of previous studies to develop ignition regime criteria. Analytical theory and direct numerical simulation were used to validate and interpret the RCF ignition data. Based on the integrated information the ignition regime criteria were extended to non-dimensional metrics which enable application of the results to practical gas turbine combustion systems.

  18. Content of carbon monoxide in the tissues of rats intoxicated with carbon monoxide in various conditions of acute exposure

    Energy Technology Data Exchange (ETDEWEB)

    Sokal, J.A.; Majka, J.; Palus, J.

    1984-12-01

    Tissue carbon monoxide (CO) content was investigated in rats severely intoxicated with CO under various exposure conditions: 1% CO for 4 min, 0.4% CO for 40 min and 0.12% CO for 12 h. Extravascular CO was determined in the heart and skeletal muscles immediately after termination of exposure, and carboxymyoglobin (MbCO) percent saturation was calculated. Total brain CO was estimated immediately after termination of exposure and after the time periods of restitution. After the same exposure conditions, MbCO percent saturation was higher in the heart than in skeletal muscle. In both types of muscle, saturation on myoglobin (Mb) with CO depended on blood carboxyhemoglobin (HbCO) level and not on the duration of exposure. The time course of CO elimination was the same for blood and brain, irrespective of CO exposure conditions. The results obtained showed that acute CO intoxication induced by long duration exposures did not involve CO accumulation in the tissues.

  19. Nitrogen-doped mesoporous carbons for high performance supercapacitors

    Science.gov (United States)

    Wu, Kai; Liu, Qiming

    2016-08-01

    The mesoporous carbons have been synthesized by using α-D(+)-Glucose, D-Glucosamine hydrochloride or their mixture as carbon precursors and mesoporous silicas (SBA-15 or MCF) as hard templates. The as-prepared products show a large pore volume (0.59-0.97 cm3 g-1), high surface areas (352.72-1152.67 m2 g-1) and rational nitrogen content (ca. 2.5-3.9 wt.%). The results of electrochemical tests demonstrate that both heteroatom doping and suitable pore structure play a decisive role in the performance of supercapacitors. The representative sample of SBA-15 replica obtained using D-Glucosamine hydrochloride only exhibits high specific capacitance (212.8 F g-1 at 0.5 A g-1) and good cycle durability (86.1% of the initial capacitance after 2000 cycles) in 6 M KOH aqueous electrolyte, which is attributed to the contribution of double layer capacitance and pseudo-capacitance. The excellent electrochemical performance makes it a promising electrode material for supercapacitors.

  20. Confident methods for the evaluation of the hydrogen content in nanoporous carbon microfibers

    Science.gov (United States)

    Culebras, Mario; Madroñero, Antonio; Cantarero, Andres; Amo, José Maria; Domingo, Concepción; López, Antonio

    2012-10-01

    Nanoporous carbon microfibers were grown by chemical vapor deposition in the vapor-liquid solid mode using different fluid hydrocarbons as precursors in different proportions. The as-grown samples were further treated in argon and hydrogen atmospheres at different pressure conditions and annealed at several temperatures in order to deduce the best conditions for the incorporation and re-incorporation of hydrogen into the microfibers through the nanopores. Since there are some discrepancies in the results on the hydrogen content obtained under vacuum conditions, in this work, we have measured the hydrogen content in the microfibers using several analytical methods in ambient conditions: surface tension, mass density, and Raman measurements. A discussion on the validity of the results obtained through the correlation between them is the purpose of the present work.

  1. Effect of Carbon Content on the Microstructure and Mechanical Properties of NbC-Ni Based Cermets

    Directory of Open Access Journals (Sweden)

    Shuigen Huang

    2018-03-01

    Full Text Available The aim of this work was to correlate the overall carbon content in NbC-Ni, NbC-Ni-VC and NbC-Ni-Mo starting powders with the resulting microstructure, hardness, and fracture toughness of Ni-bonded NbC cermets. A series of NbC-Ni, NbC-Ni-VC and NbC-Ni-Mo cermets with different carbon content were prepared by conventional liquid phase sintering for 1 h at 1420 °C in vacuum. Microstructural analysis of the fully densified cermets was performed by electron probe microanalysis (EPMA to assess the effect of carbon and VC or Mo additions on the NbC grain growth and morphology. A decreased carbon content in the starting powder mixtures resulted in increased dissolution of Nb, V, and Mo in the Ni binder and a decreased C/Nb ratio in the NbC based carbide phase. The Vickers hardness (HV30 and Palmqvist indentation toughness were found to decrease significantly with an increasing carbon content in the Mo-free cermets, whereas an antagonistic correlation between hardness and toughness was obtained as a function of the Mo-content in Mo-modified NbC cermets. To obtain optimized mechanical properties, methods to control the total carbon content of NbC-Ni mixtures were proposed and the prepared cermets were investigated in detail.

  2. Determination of local carbon content in austenite during intercritical annealing of dual phase steels by PEELS analysis

    International Nuclear Information System (INIS)

    Garcia-Junceda, A.; Caballero, F.G.; Capdevila, C.; Garcia de Andres, C.

    2007-01-01

    Parallel electron energy loss spectroscopy has allowed to analyse and quantify local variations in the carbon concentration of austenite islands transformed during the intercritical annealing treatment of commercial dual-phase steels. These changes in the carbon content of different austenite regions are responsible for the different volume fractions of tempered martensite, martensite and retained austenite obtained after intercritical annealing and overaging treatment. This technique reveals how carbon distribution in austenite evolves as the transformation process advances

  3. The efficiency of different types of wood charcoal on increasing carbon content on surfaces of low carbon steel in the pack carburizing process

    Directory of Open Access Journals (Sweden)

    Narongsak Thammachot

    2014-09-01

    Full Text Available The purpose of this research is to compare the efficiency of five types of wood charcoal, eucalyptus, coconut shell, tamarind, bamboo and cassava root in increasing carbon content on surfaces of low carbon steel by the pack carburizing process. The experiment for pack carburized low carbon steel (grade AISI 1020 was conducted by using the different wood charcoals as carburizers, mixed with 10% limestone (by weight as the energizer. The carburizing temperature of 950°C, and carburizing times of 2, 4 and 6 hours were used in the experiment. After grinding, the specimens in each case were checked for carbon content by optical emission spectroscopy. Micro-Vickers hardness testing and microstructure inspections were carried out. The results of the experiment showed that the efficiency of eucalyptus charcoal as the carburizer (for increasing carbon content on surfaces of low carbon steel was higher than that of tamarind, cassava root, coconut shell and bamboo charcoals. The averages for carbon content were: 1.16, 1.06, 0.97, 0.83 and 0.77% respectively.

  4. An objective method for High Dynamic Range source content selection

    DEFF Research Database (Denmark)

    Narwaria, Manish; Mantel, Claire; Da Silva, Matthieu Perreira

    2014-01-01

    With the aim of improving the immersive experience of the end user, High Dynamic Range (HDR) imaging has been gaining popularity. Therefore, proper validation and performance benchmarking of HDR processing algorithms is a key step towards standardization and commercial deployment. A crucial...... component of such validation studies is the selection of a challenging and balanced set of source (reference) HDR content. In order to facilitate this, we present an objective method based on the premise that a more challenging HDR scene encapsulates higher contrast, and as a result will show up more...

  5. Separation and determination of high-carbon alcohols using method of column chromatographic and gas-chromatographic analysis

    International Nuclear Information System (INIS)

    Kang Zhongrong; Li Biping; Zeng Yongchang

    1988-01-01

    This paper describes the separation and determination of high-carbon alcohols from amine extractant by using the method of column chromatography of aluminium oxide and gas-chromatographic analysis. The total conent of high-carbon alcohols is determined by the method of column chromatography, while the components of the high-carbon alcohols and their relative contents are determined by the method of gas-chromatography. A simple reliable and practical method is provided for the analysis of high-carbon alcohol from the amine extractant in this paper

  6. Beyond clay - using selective extractions to improve predictions of soil carbon content

    Science.gov (United States)

    Rasmussen, C.; Berhe, A. A.; Blankinship, J. C.; Crow, S. E.; Druhan, J. L.; Heckman, K. A.; Keiluweit, M.; Lawrence, C. R.; Marin-Spiotta, E.; Plante, A. F.; Schaedel, C.; Schimel, J.; Sierra, C. A.; Thompson, A.; Wagai, R.; Wieder, W. R.

    2016-12-01

    A central component of modern soil carbon (C) models is the use of clay content to scale the relative partitioning of decomposing plant material to respiration and mineral stabilized soil C. However, numerous pedon to plot scale studies indicate that other soil mineral parameters, such as Fe- or Al-oxyhydroxide content and specific surface area, may be more effective than clay alone for predicting soil C content and stabilization. Here we directly address the following question: Are there soil physicochemical parameters that represent mineral C association and soil C content that can replace or be used in conjunction with clay content as scalars in soil C models. We explored the relationship of soil C content to a number of soil physicochemical and physiographic parameters using the National Cooperative Soil Survey database that contains horizon level data for > 62,000 pedons spanning global ecoregions and geographic areas. The data indicated significant variation in the degree of correlation among soil C, clay and Fe-/Al-oxyhydroxides with increasing moisture variability. Specifically, dry, water-limited systems (PET/MAP > 1) presented strong positive correlations between clay and soil C, that decreased significantly to little or no correlation in wet, energy-limited systems (PET/MAP soil C to oxalate extractable Al+Fe increased significantly with increasing moisture availability. This pattern was particularly well expressed for subsurface B horizons. Multivariate analyses indicated similar patterns, with clear climate and ecosystem level variation in the degree of correlation among soil C and soil physicochemical properties. The results indicate a need to modify current soil C models to incorporate additional C partitioning parameters that better account for climate and ecoregion variability in C stabilization mechanisms.

  7. Effect of small addition of Cr on stability of retained austenite in high carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, Rumana; Pahlevani, Farshid, E-mail: f.pahlevani@unsw.edu.au; Sahajwalla, Veena

    2017-03-15

    High carbon steels with dual phase structures of martensite and austenite have considerable potential for industrial application in high abrasion environments due to their hardness, strength and relatively low cost. To design cost effective high carbon steels with superior properties, it is crucial to identify the effect of Chromium (Cr) on the stability of retained austenite (RA) and to fully understand its effect on solid-state phase transition. This study addresses this important knowledge gap. Using standard compression tests on bulk material, quantitative X-ray diffraction analysis, nano-indentation on individual austenitic grains, transmission electron microscopy and electron backscatter diffraction–based orientation microscopy techniques, the authors investigated the effect of Cr on the microstructure, transformation behaviour and mechanical stability of retained austenite in high carbon steel, with varying Cr contents. The results revealed that increasing the Cr %, altered the morphology of the RA and increased its stability, consequently, increasing the critical pressure for martensitic transformation. This study has critically addressed the elastoplastic behaviour of retained austenite – and provides a deep understanding of the effect of small additions of Cr on the metastable austenite of high carbon steel from the macro- to nano-level. Consequently, it paves the way for new applications for high carbon low alloy steels. - Highlights: • Effect of small addition of Cr on metastable austenite of high carbon steel from the macro- to nano-level • A multi-scale study of elastoplastic behaviour of retained austenite in high carbon steel • The mechanical stability of retained austenite during plastic deformation increased with increasing Cr content • Effect of grain boundary misorientation angle on hardness of individual retained austenite grains in high carbon steel.

  8. Palygorskite Hybridized Carbon Nanocomposite as a High ...

    African Journals Online (AJOL)

    TEM and XRD results showed that acid treatment had an effective impact on ... The electrochemical results showed that the addition of palygorskite into the carbon facilitated the formation of OHads or Oads on the ... and cost-efficient way to improve the electrocatalytic performance of carbon ... AJOL African Journals Online.

  9. Effect of high pressurized carbon dioxide on Escherichia coli ...

    African Journals Online (AJOL)

    Carbon dioxide at high pressure can retard microbial growth and sometimes kill microorganisms depending on values of applied pressure, temperature and exposure time. In this study the effect of high pressurised carbon dioxide (HPCD) on Escherichia coli was investigated. Culture of E. coli was subjected to high ...

  10. Bonding Unidirectional Carbon Nanotube with Carbon for High Performance

    Science.gov (United States)

    2015-06-24

    samples in a dilute aqueous solution of AgNO3 and placing them under a UV lamp . After 30 minutes of UV exposure, an obvious color change from black...purposefully avoided due to the potential damages to CNTs and the uncertainty on their effect on carbonization. Millimeter-long CNTs were used to develop...inter-connected network of the sheet, which led to foam-like recovery of the structure after compression. The ACNT/C foams can be tuned by changing

  11. Influences of carbon content and coating carbon thickness on properties of amorphous CoSnO{sub 3}@C composites as anode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Fuqiang [Key Laboratory of Lithium Battery Materials of Jiangsu Province, Institute of chemical power sources, Soochow University, Suzhou 215006 (China); Fang, Guoqing [Key Laboratory of Lithium Battery Materials of Jiangsu Province, Institute of chemical power sources, Soochow University, Suzhou 215006 (China); Changzhou Institute of Energy Storage Materials and Devices, Changzhou 213000 (China); Zhang, Ruixue [Key Laboratory of Lithium Battery Materials of Jiangsu Province, Institute of chemical power sources, Soochow University, Suzhou 215006 (China); Xu, Yanhui; Zheng, Junwei [Key Laboratory of Lithium Battery Materials of Jiangsu Province, Institute of chemical power sources, Soochow University, Suzhou 215006 (China); College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006 (China); Li, Decheng, E-mail: lidecheng@suda.edu.cn [Key Laboratory of Lithium Battery Materials of Jiangsu Province, Institute of chemical power sources, Soochow University, Suzhou 215006 (China); College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006 (China)

    2014-08-30

    Highlights: • The thickness of carbon coating layers can be successfully controlled through varying molar concentration of aqueous glucose solution. • Coating carbon thickness and carbon content are two important factors on the electrochemical performances of CoSnO3@C. • CoSnO{sub 3}@C under optimized conditions exhibits the optimal balance between the volume buffering effect and reversible capacity. • As-prepared CoSnO{sub 3}@C under optimized conditions shows excellent electrochemical performances, whose reversible capacity could reach 491 mA h g{sup −1} after 100 cycles. - Abstract: A series of core–shell carbon coated amorphous CoSnO{sub 3} (CoSnO{sub 3}@C) with different carbon content are synthesized. Effects of carbon content and coating carbon thickness on the physical and electrochemical performances of the samples were studied in detail. The samples were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), galvanostatic charge–discharge and AC impedance spectroscopy, respectively. The results indicate that controlling the concentration of aqueous glucose solution influences the generation of in-situ carbon layer thickness. The optimal concentration of aqueous glucose solution, carbon content and carbon layer thickness are suggested as 0.25 M, 35.1% and 20 nm, respectively. CoSnO{sub 3}@C composite prepared under the optimal conditions exhibits excellent cycling performance, whose reversible capacity could reach 491 mA h g{sup −1} after 100 cycles.

  12. The Effect of Paved Roads on Organic Carbon Content of Soil in Taham Dam Basin

    Directory of Open Access Journals (Sweden)

    Mazyar Peyda

    2016-09-01

    Full Text Available Background: Contamination of water and soil through non-point sources such as road runoff causes environmental concern. The aim of this study is to determine the effect of Zanjan – Chavarzagh road on the total organic carbon (TOC content of sediments in tributaries and the river that lead to Taham Lake. Methods: In tributaries and the river 69 soil and sediment samples were taken and the Total organic carbon (TOC was measured according to Walkely-Black method. Also, Taham Dam Basin area and its hydrologic properties were calculated by Global Information System (GIS software. Results: Results showed that, TOC concentration has a significant negative relationship with the distance from the lake. TOC in soil samples taken from hillside of the road had significantly lower mean and median concentration ( median= 3262 , mean = 4083 ± 3461 mg/kg than the valley side ( median = 5324 , mean = 6178 ± 3980 mg/kg. The check dams across the tributaries and the river have not been effective in the reduction of TOC in sediments. Conclusion: Roads in the Taham Dam Basin, increases TOC content of soil and sediments in Taham dam basin. TOC moves toward Taham dam lake.

  13. High-Flux Carbon Molecular Sieve Membranes for Gas Separation.

    Science.gov (United States)

    Richter, Hannes; Voss, Hartwig; Kaltenborn, Nadine; Kämnitz, Susanne; Wollbrink, Alexander; Feldhoff, Armin; Caro, Jürgen; Roitsch, Stefan; Voigt, Ingolf

    2017-06-26

    Carbon membranes have great potential for highly selective and cost-efficient gas separation. Carbon is chemically stable and it is relative cheap. The controlled carbonization of a polymer coating on a porous ceramic support provides a 3D carbon material with molecular sieving permeation performance. The carbonization of the polymer blend gives turbostratic carbon domains of randomly stacked together sp 2 hybridized carbon sheets as well as sp 3 hybridized amorphous carbon. In the evaluation of the carbon molecular sieve membrane, hydrogen could be separated from propane with a selectivity of 10 000 with a hydrogen permeance of 5 m 3 (STP)/(m 2 hbar). Furthermore, by a post-synthesis oxidative treatment, the permeation fluxes are increased by widening the pores, and the molecular sieve carbon membrane is transformed from a molecular sieve carbon into a selective surface flow carbon membrane with adsorption controlled performance and becomes selective for carbon dioxide. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. SCC with high volume of fly ash content

    Directory of Open Access Journals (Sweden)

    Bakhrakh Anton

    2017-01-01

    Full Text Available Self-compacting concrete is a very perspective building material. It provides great benefits during the construction of heavily reinforced buildings. SCC has outstanding properties such as high flowability, dense structure and high strength due to specific quality of aggregates, fillers, their proportion in mix, use of polycarboxylate-based superplasticizers. Main disadvantages of SCC are high price and the difficulty of obtaining a proper mix. Use of fillers, such as fly ash type F, is a way to make SCC cheaper by replacing part of cement. Fly ash also provides some technological and operating advantages. In this paper the influence of high volume (60% from cement fly ash type F on the properties of concrete mixture and hardened concrete is investigated. The result of the work shows the possibility of reduction the cost of SCC using ordinary fillers and high amount of fly ash. The investigated SCC has low speed of hardening (7-day compressive strength at the range of 41.8 MPa and high volume of entrained air content (3.5%.

  15. High efficiency carbon nanotube thread antennas

    Science.gov (United States)

    Amram Bengio, E.; Senic, Damir; Taylor, Lauren W.; Tsentalovich, Dmitri E.; Chen, Peiyu; Holloway, Christopher L.; Babakhani, Aydin; Long, Christian J.; Novotny, David R.; Booth, James C.; Orloff, Nathan D.; Pasquali, Matteo

    2017-10-01

    Although previous research has explored the underlying theory of high-frequency behavior of carbon nanotubes (CNTs) and CNT bundles for antennas, there is a gap in the literature for direct experimental measurements of radiation efficiency. These measurements are crucial for any practical application of CNT materials in wireless communication. In this letter, we report a measurement technique to accurately characterize the radiation efficiency of λ/4 monopole antennas made from the CNT thread. We measure the highest absolute values of radiation efficiency for CNT antennas of any type, matching that of copper wire. To capture the weight savings, we propose a specific radiation efficiency metric and show that these CNT antennas exceed copper's performance by over an order of magnitude at 1 GHz and 2.4 GHz. We also report direct experimental observation that, contrary to metals, the radiation efficiency of the CNT thread improves significantly at higher frequencies. These results pave the way for practical applications of CNT thread antennas, particularly in the aerospace and wearable electronics industries where weight saving is a priority.

  16. Physical properties and organic carbon content of a Rhodic Kandiudox fertilized with pig slurry and poultry litter

    Directory of Open Access Journals (Sweden)

    Luiz Paulo Rauber

    2012-08-01

    Full Text Available The impact of pig slurry and poultry litter fertilization on soils depends on the conditions of use and the amounts applied. This study evaluated the effect of organic fertilizers after different application periods in different areas on the physical properties and organic carbon contents of a Rhodic Kandiudox, in Concordia, Santa Catarina, in Southern Brazil. The treatments consisted of different land uses and periods of pig and poultry litter fertilization: silage maize (M7 years, silage maize (M20 years, annual ryegrass pasture (P3 years, annual ryegrass pasture (P15 years, perennial pasture (PP20 years, yerba mate tea (Mt20 years, native forest (NF, and native pasture without manure application (P0. The 0-5, 5-10 and 10-20 cm soil layers were sampled and analyzed for total organic carbon, total nitrogen and soil physical properties such as density, porosity, aggregation, degree of flocculation, and penetration resistance. The organic carbon levels in the cultivated areas treated with organic fertilizer were even lower than in native forest soil. The organic fertilizers and studied management systems reduced the flocculation degree of the clay particles, and low macroporosity was observed in some areas. Despite these changes, a good soil physical structure was maintained, e.g., soil density and resistance to penetration were below the critical limits, whereas aggregate stability was high, which is important to reduce water erosion in these areas with rugged terrain in western Santa Catarina, used for pig and poultry farming.

  17. Desorption behaviors of BDE-28 and BDE-47 from natural soils with different organic carbon contents

    International Nuclear Information System (INIS)

    Liu Wenxin; Cheng Fangfang; Li Weibo; Xing Baoshan; Tao Shu

    2012-01-01

    Desorption kinetic and isothermal characteristics of BDE-28 and BDE-47 were investigated using natural soils with different organic carbon fractions. The results indicated that a two-compartment first-order model with dominant contribution of slow desorption could adequately describe the released kinetics of studied PBDEs. Desorption isotherms of different samples could be fitted well by linear distribution model or nonlinear Freundlich model. Moreover, most desorption procedures roughly exhibited hysteresis with respect to preceding sorption ones. At the statistically significant level of 0.05 or 0.1, total organic carbon content (f OC ) exhibited significant correlations with the fitted parameters by the isothermal models. The correlations of f OC and SOM fractions (e.g., fulvic acid and humin) with the single point desorption coefficients at lower aqueous concentrations of studied PBDEs were significant; while at higher aqueous concentrations, the relationships were less significant or insignificant. Our findings may facilitate a comprehensive understanding on behaviors of PBDEs in soil systems. - Highlights: ► A two-compartment first-order kinetic model for the PBDEs studied was established. ► Isotherm was fitted well by a linear distribution or a nonlinear Freundlich model. ► Desorption commonly exhibited somewhat hysteresis relative to sorption. ► Soil organic carbon fractions showed close correlations with the model parameters. - Two-compartment first-order model, and linear distribution model or nonlinear Freundlich model could well elucidate desorption kinetics and isotherms of PBDEs in natural soils, respectively.

  18. Morphology, Microstructure, and Hydrogen Content of Carbon Nanostructures Obtained by PECVD at Various Temperatures

    Directory of Open Access Journals (Sweden)

    M. Acosta Gentoiu

    2017-01-01

    Full Text Available Carbon nanostructures were obtained by acetylene injection into an argon plasma jet in the presence of hydrogen. The samples were synthesized in similar conditions, except that the substrate deposition temperatures TD were varied, ranging from 473 to 973 K. A strong dependence of morphology, structure, and graphitization upon TD was found. We obtained vertical aligned carbon nanotubes (VA-CNTs at low temperatures as 473 K, amorphous carbon nanoparticles (CNPs at temperatures from about 573 to 673 K, and carbon nanowalls (CNWs at high temperatures from 773 to 973 K. Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, elastic recoil detection analysis, X-ray photoelectron spectroscopy, and Raman spectroscopy were used to substantiate the differences in these material types. It is known that hydrogen concentration modifies strongly the properties of the materials. Different concentrations of hydrogen-bonded carbon could be identified in amorphous CNP, VA-CNT, and CNW. Also, the H : C ratios along depth were determined for the obtained materials.

  19. A high-performance carbon derived from polyaniline for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Jun [Harbin Engineering University, Harbin (China). Key Laboratory of Superlight Materials and Surface Technology; College of Automation, Harbin Engineering University, Harbin (China); Wei, Tong; Fan, Zhuangjun; Li, Tianyou [Harbin Engineering University, Harbin (China). Key Laboratory of Superlight Materials and Surface Technology; Qiao, Wenming [Harbin Engineering University, Harbin (China). Coll. of Material Science and Chemical Engineering; Zhang, Lijun; Zhao, Qiankun [College of Automation, Harbin Engineering University, Harbin (China)

    2010-10-15

    Activated carbon derived from rod-shaped polyaniline (the diameter of 170 nm) was synthesized by carbonization and subsequent activation with KOH. The obtained activated carbon exhibits a high specific capacitance (455 F g{sup -1}) and remarkable rate capability due to its high specific surface area (1976 m{sup 2}g{sup -1}), narrow pore size distribution (< 3 nm) as well as short diffusion length. It is indicated that the promising synthetic method used in this work can pave the way for designing new carbon based materials from different polymers for high-performance energy applications. (author)

  20. Influence of W content on tribological performance of W-doped diamond-like carbon coatings under dry friction and polyalpha olefin lubrication conditions

    International Nuclear Information System (INIS)

    Fu, Zhi-qiang; Wang, Cheng-biao; Zhang, Wei; Wang, Wei; Yue, Wen; Yu, Xiang; Peng, Zhi-jian; Lin, Song-sheng; Dai, Ming-jiang

    2013-01-01

    Highlights: • W-doped DLC coating with various W contents was fabricated. • Friction and wear of DLC coated sample was studied. • The lubricant additive was T307. • The influence of W content on friction under lubrication was unveiled. • The influence of W content on wear under lubrication was studied. - Abstract: The influence on tungsten content on the structure, mechanical properties and tribological performance of W-doped diamond-like carbon (DLC) coatings was studied by X-ray photoelectron spectroscopy, nano-indentation, scratch test, and ball-on-disk friction test. It was found that with increasing W content, the content of WC and free W in the coatings is increased while the content of sp 3 -C in the coatings is decreased. The effect of W content on the hardness and elastic modulus of the coatings is indistinctive, but there exists the highest critical load of scratch test of above 100 N when W content is 3.08 at.%. With the increase of W content, the friction coefficients of W-doped DLC coatings under dry friction conditions are increased while the friction coefficients of W-doped DLC coatings under polyalpha olefin (PAO) lubrication are decreased. With the increase of W content, the wear rates of the DLC-coated samples under dry friction conditions show a minimum value; under pure PAO lubrication, the influence of W content on the wear rates of the DLC-coated samples is indistinctive when the W content is below 10.73 at.% while the wear rates are increased with increasing W content from 10.73 at.% to 24.09 at.%; when lubricated by PAO + thiophosphoric acid amine (T307) salt, the samples coated with the undoped DLC or the W-doped DLC with high W content exhibit low wear rates

  1. A content analysis of tweets about high-potency marijuana.

    Science.gov (United States)

    Cavazos-Rehg, Patricia A; Sowles, Shaina J; Krauss, Melissa J; Agbonavbare, Vivian; Grucza, Richard; Bierut, Laura

    2016-09-01

    "Dabbing" involves heating extremely concentrated forms of marijuana to high temperatures and inhaling the resulting vapor. We studied themes describing the consequences of using highly concentrated marijuana by examining the dabbing-related content on Twitter. Tweets containing dabbing-related keywords were collected from 1/1-1/31/2015 (n=206,854). A random sample of 5000 tweets was coded for content according to pre-determined categories about dabbing-related behaviors and effects experienced using a crowdsourcing service. An examination of tweets from the full sample about respiratory effects and passing out was then conducted by selecting tweets with relevant keywords. Among the 5000 randomly sampled tweets, 3540 (71%) were related to dabbing marijuana concentrates. The most common themes included mentioning current use of concentrates (n=849; 24%), the intense high and/or extreme effects from dabbing (n=763; 22%) and excessive/heavy dabbing (n=517; 15%). Extreme effects included both physiological (n=124/333; 37%) and psychological effects (n=55/333; 17%). The most common physiologic effects, passing out (n=46/333; 14%) and respiratory effects (n=30/333; 9%), were then further studied in the full sample of tweets. Coughing was the most common respiratory effect mentioned (n=807/1179; 68%), and tweeters commonly expressed dabbing with intentions to pass out (416/915; 45%). This study adds to the limited understanding of marijuana concentrates and highlights self-reported physical and psychological effects from this type of marijuana use. Future research should further examine these effects and the potential severity of health consequences associated with concentrates. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. High GC content causes orphan proteins to be intrinsically disordered.

    Directory of Open Access Journals (Sweden)

    Walter Basile

    2017-03-01

    Full Text Available De novo creation of protein coding genes involves the formation of short ORFs from noncoding regions; some of these ORFs might then become fixed in the population. These orphan proteins need to, at the bare minimum, not cause serious harm to the organism, meaning that they should for instance not aggregate. Therefore, although the creation of short ORFs could be truly random, the fixation should be subjected to some selective pressure. The selective forces acting on orphan proteins have been elusive, and contradictory results have been reported. In Drosophila young proteins are more disordered than ancient ones, while the opposite trend is present in yeast. To the best of our knowledge no valid explanation for this difference has been proposed. To solve this riddle we studied structural properties and age of proteins in 187 eukaryotic organisms. We find that, with the exception of length, there are only small differences in the properties between proteins of different ages. However, when we take the GC content into account we noted that it could explain the opposite trends observed for orphans in yeast (low GC and Drosophila (high GC. GC content is correlated with codons coding for disorder promoting amino acids. This leads us to propose that intrinsic disorder is not a strong determining factor for fixation of orphan proteins. Instead these proteins largely resemble random proteins given a particular GC level. During evolution the properties of a protein change faster than the GC level causing the relationship between disorder and GC to gradually weaken.

  3. Production of JET fuel containing molecules of high hydrogen content

    Directory of Open Access Journals (Sweden)

    Tomasek Sz.

    2017-12-01

    Full Text Available The harmful effects of aviation can only be reduced by using alternative fuels with excellent burning properties and a high hydrogen content in the constituent molecules. Due to increasing plastic consumption the amount of the plastic waste is also higher. Despite the fact that landfill plastic waste has been steadily reduced, the present scenario is not satisfactory. Therefore, the aim of this study is to produce JET fuel containing an alternative component made from straight-run kerosene and the waste polyethylene cracking fraction. We carried out our experiments on a commercial NiMo/Al2O3/P catalyst at the following process parameters: T=200-300°C, P=40 bar, LHSV=1.0-3.0 h-1, hydrogen/hydrocarbon ratio= 400 Nm3/m3. We investigated the effects of the feedstocks and the process parameters on the product yields, the hydrodesulfurization and hydrodearomatization efficiencies, and the main product properties. The liquid product yields varied between 99.7-99.8%. As a result of the hydrogenation the sulfur (1-1780 mg/kg and the aromatic contents (9.0-20.5% of the obtained products and the values of their smoke points (26.0-34.7 mm fulfilled the requirements of JET fuel standard. Additionally, the concentration of paraffins increased in the products and the burning properties were also improved. The freezing points of the products were higher than -47°C, therefore product blending is needed.

  4. Towards high-siderophore-content foods: optimisation of coprogen production in submerged cultures of Penicillium nalgiovense.

    Science.gov (United States)

    Emri, Tamás; Tóth, Viktória; Nagy, Csilla Terézia; Nagy, Gábor; Pócsi, Imre; Gyémánt, Gyöngyi; Antal, Károly; Balla, József; Balla, György; Román, Gyula; Kovács, István; Pócsi, István

    2013-07-01

    Fungal siderophores are likely to possess atheroprotective effects in humans, and therefore studies are needed to develop siderophore-rich food additives or functional foods to increase the siderophore uptake in people prone to cardiovascular diseases. In this study the siderophore contents of mould-ripened cheeses and meat products were analysed and the coprogen production by Penicillium nalgiovense was characterised. High concentrations of hexadentate fungal siderophores were detected in penicillia-ripened Camembert- and Roquefort-type cheeses and also in some sausages. In one sausage fermented by P. nalgiovense, the siderophore content was comparable to those found in cheeses. Penicillium nalgiovense produced high concentrations of coprogen in submerged cultures, which were affected predominantly by the available carbon and nitrogen sources under iron starvation. Considerable coprogen yields were still detectable in the presence of iron when the fermentation medium was supplemented with the iron chelator Na₂-EDTA or when P. nalgiovense was co-cultivated with Saccharomyces cerevisiae. These data may be exploitable in the future development of high-siderophore-content foods and/or food additives. Nevertheless, the use of P. nalgiovense fermentation broths for these purposes may be limited by the instability of coprogen in fermentation media and by the β-lactam production by the fungus. © 2012 Society of Chemical Industry.

  5. Electrochemical Hydrogen Storage in a Highly Ordered Mesoporous Carbon

    Directory of Open Access Journals (Sweden)

    Dan eLiu

    2014-10-01

    Full Text Available A highly order mesoporous carbon has been synthesized through a strongly acidic, aqueous cooperative assembly route. The structure and morphology of the carbon material were investigated using TEM, SEM and nitrogen adsorption-desorption isotherms. The carbon was proven to be meso-structural and consisted of graphitic micro-domain with larger interlayer space. AC impedance and electrochemical measurements reveal that the synthesized highly ordered mesoporous carbon exhibits a promoted electrochemical hydrogen insertion process and improved capacitance and hydrogen storage stability. The meso-structure and enlarged interlayer distance within the highly ordered mesoporous carbon are suggested as possible causes for the enhancement in hydrogen storage. Both hydrogen capacity in the carbon and mass diffusion within the matrix were improved.

  6. The effect of soll water conditions on carbon isotope discrimination and minerals contents in spring-planted wheat

    International Nuclear Information System (INIS)

    Zhu Lin; Liang Zongsuo; Xu Xing; Li Shuhua

    2008-01-01

    Carbon isotope discrimination (triangle open 13 C) has been proposed as indirect selection criterion for transpiration efficiency and grain yield in wheat. However, because of high cost for triangle open 13 C analysis, attempts have been made to identify alternative screening criteria. Ash content (m a ) has been proposed as an alternative criterion for triangle open 13 C in wheat and barley. A pot experiment with three water treatments (45% ± 5% FC, 55% ± 5% FC and 75% ± 5%FC) was conducted and flag leaf triangle open 13 C (triangle openL a ), contents of ash, potassium (K), magnesium (Mg) and calcium (Ca) were measured to study the relationships between triangle open, mineral composition in spring planted bread wheat (Triticum aestivum L.). In the light of the results obtained in this research, the traits measured showed significant differences among the three water treatments. There were variations in triangle openL a between the genotypes derived from contrasting environments. The improved varieties or advanced lines bred in irrigated areas displayed higher triangle open 13 C values, while the improved and local varieties bred in rain-fed areas exhibited lower triangle open 13 C values Significant positive correlations were found between triangle open 13 C and m a in seedlings and second fully developed leaves at elongation stage and in flag leaves at anthesis stage in severe drought treatment (T 1 ) (r=0.790, P 13 C was negatively associated with potassium (K) content in flag leaves in T 2 (r=0.813, P 2 and T 3 (r=0.725, P 13 C and calcium (Ca) content in flag leaves in T 3 (r=0.708, P a is a possible alternative criterion of triangle open 13 C in vegetative organs especially in stressed environments. K, Mg and Ca contents in flag leaf under moderate water stress or feasible water conditions might be new predictive criteria of triangle openL a . (authors)

  7. Clay content drives carbon stocks in soils under a plantation of Eucalyptus saligna Labill. in southern Brazil

    Directory of Open Access Journals (Sweden)

    Tanise Luisa Sausen

    2014-06-01

    Full Text Available Soil carbon accumulation is largely dependent on net primary productivity. To our knowledge, there have been no studies investigating the dynamics of carbon accumulation in weathered subtropical soils, especially in managed eucalyptus plantations. We quantified the seasonal input of leaf litter, the leaf decomposition rate and soil carbon stocks in an commercial plantation of Eucalyptus saligna Labill. in southern Brazil. Our goal was to evaluate, through multiple linear regression, the influence that certain chemical characteristics of litter, as well as chemical and physical characteristics of soil, have on carbon accumulation in soil organic matter fractions. Variables related to the chemical composition of litter were not associated with the soil carbon stock in the particulate and mineral fractions. However, certain soil characteristics were significantly associated with the carbon stock in both fractions. The concentrations of nutrients associated with plant growth and productivity, such as phosphorus, sulfur, copper and zinc, were associated with variations in the labile carbon pool (particulate fraction. Clay content was strongly associated with the carbon stock in the mineral fraction. The carbon accumulation and stabilization in weathered subtropical Ultisol seems to be mainly associated with the intrinsic characteristics of the soil, particularly clay content, rather than with the quantity, chemical composition or decomposition rate of the litter.

  8. Cermet anode compositions with high content alloy phase

    Science.gov (United States)

    Marschman, Steven C.; Davis, Norman C.

    1989-01-01

    Cermet electrode compositions comprising NiO-NiFe.sub.2 O.sub.4 -Cu-Ni, and methods for making, are disclosed. Addition of nickel metal prior to formation and densification of a base mixture into the cermet allows for an increase in the total amount of copper and nickel that can be contained in the NiO-NiFe.sub.2 O.sub.4 oxide system. Nickel is present in a base mixture weight concentration of from 0.1% to 10%. Copper is present in the alloy phase in a weight concentration of from 10% to 30% of the densified composition. Such cermet electrodes can be formed to have electrical conductivities well in excess of 100 ohm.sup.-1 cm.sup.-1. Other alloy and oxide system cermets having high content metal phases are also expected to be manufacturable in accordance with the invention.

  9. Automation in high-content flow cytometry screening.

    Science.gov (United States)

    Naumann, U; Wand, M P

    2009-09-01

    High-content flow cytometric screening (FC-HCS) is a 21st Century technology that combines robotic fluid handling, flow cytometric instrumentation, and bioinformatics software, so that relatively large numbers of flow cytometric samples can be processed and analysed in a short period of time. We revisit a recent application of FC-HCS to the problem of cellular signature definition for acute graft-versus-host-disease. Our focus is on automation of the data processing steps using recent advances in statistical methodology. We demonstrate that effective results, on par with those obtained via manual processing, can be achieved using our automatic techniques. Such automation of FC-HCS has the potential to drastically improve diagnosis and biomarker identification.

  10. High-performance membrane-electrode assembly with an optimal polytetrafluoroethylene content for high-temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Jeong, Gisu; Kim, MinJoong; Han, Junyoung

    2016-01-01

    Although high-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) have a high carbon monoxide tolerance and allow for efficient water management, their practical applications are limited due to their lower performance than conventional low-temperature PEMFCs. Herein, we present a high......-performance membrane-electrode assembly (MEA) with an optimal polytetrafluoroethylene (PTFE) content for HT-PEMFCs. Low or excess PTFE content in the electrode leads to an inefficient electrolyte distribution or severe catalyst agglomeration, respectively, which hinder the formation of triple phase boundaries...

  11. Variations in pore characteristics in high volatile bituminous coals: Implications for coal bed gas content

    Science.gov (United States)

    Mastalerz, Maria; Drobniak, A.; Strapoc, D.; Solano-Acosta, W.; Rupp, J.

    2008-01-01

    The Seelyville Coal Member of the Linton Formation (Pennsylvanian) in Indiana was studied to: 1) understand variations in pore characteristics within a coal seam at a single location and compare these variations with changes occurring between the same coal at different locations, 2) elaborate on the influence of mineral-matter and maceral composition on mesopore and micropore characteristics, and 3) discuss implications of these variations for coal bed gas content. The coal is high volatile bituminous rank with R0 ranging from 0.57% to 0.60%. BET specific surface areas (determined by nitrogen adsorption) of the coals samples studied range from 1.8 to 22.9??m2/g, BJH adsorption mesopore volumes from 0.0041 to 0.0339??cm3/g, and micropore volumes (determined by carbon dioxide adsorption) from 0.0315 to 0.0540??cm3/g. The coals that had the largest specific surface areas and largest mesopore volumes occur at the shallowest depths, whereas the smallest values for these two parameters occur in the deepest coals. Micropore volumes, in contrast, are not depth-dependent. In the coal samples examined for this study, mineral-matter content influenced both specific surface area as well as mesopore and micropore volumes. It is especially clear in the case of micropores, where an increase in mineral-matter content parallels the decrease of micropore volume of the coal. No obvious relationships were observed between the total vitrinite content and pore characteristics but, after splitting vitrinite into individual macerals, we see that collotelinite influences both meso- and micropore volume positively, whereas collodetrinite contributes to the reduction of mesopore and micropore volumes. There are large variations in gas content within a single coal at a single location. Because of this variability, the entire thickness of the coal must be desorbed in order to determine gas content reliably and to accurately calculate the level of gas saturation. ?? 2008 Elsevier B.V. All

  12. Molten salt oxidation of organic hazardous waste with high salt content.

    Science.gov (United States)

    Lin, Chengqian; Chi, Yong; Jin, Yuqi; Jiang, Xuguang; Buekens, Alfons; Zhang, Qi; Chen, Jian

    2018-02-01

    Organic hazardous waste often contains some salt, owing to the widespread use of alkali salts during industrial manufacturing processes. These salts cause complications during the treatment of this type of waste. Molten salt oxidation is a flameless, robust thermal process, with inherent capability of destroying the organic constituents of wastes, while retaining the inorganic ingredients in the molten salt. In the present study, molten salt oxidation is employed for treating a typical organic hazardous waste with a high content of alkali salts. The hazardous waste derives from the production of thiotriazinone. Molten salt oxidation experiments have been conducted using a lab-scale molten salt oxidation reactor, and the emissions of CO, NO, SO 2 , HCl and dioxins are studied. Impacts are investigated from the composition of the molten salts, the types of feeding tube, the temperature of molten carbonates and the air factor. Results show that the waste can be oxidised effectively in a molten salt bath. Temperature of molten carbonates plays the most important role. With the temperature rising from 600 °C to 750 °C, the oxidation efficiency increases from 91.1% to 98.3%. Compared with the temperature, air factor has but a minor effect, as well as the composition of the molten salts and the type of feeding tube. The molten carbonates retain chlorine with an efficiency higher than 99.9% and the emissions of dioxins are below 8 pg TEQ g -1 sample. The present study shows that molten salt oxidation is a promising alternative for the disposal of organic hazardous wastes containing a high salt content.

  13. Adsorption of sulfamethoxazole and sulfapyridine antibiotics in high organic content soils.

    Science.gov (United States)

    Chen, Kuen-Lin; Liu, Li-Chun; Chen, Wan-Ru

    2017-12-01

    Many antibiotics, including sulfonamides, are being frequently detected in soil and groundwater. Livestock waste is an important source of antibiotic pollution, and sulfonamides may be present along with organic-rich substances. This study aims to investigate the sorption reaction of two sulfonamides, sulfamethoxazole (SMZ) and sulfapyridine (SPY) in two organic-rich sorbents: a commercial peat soil (38.41% carbon content) and a composted manure (24.33% carbon content). Batch reactions were conducted to evaluate the impacts of pH (4.5-9.5) and background ions (0.001 M-0.1 M CaCl 2 ) on their sorption. Both linear partitioning and Freundlich sorption isotherms fit the reaction well. The n values of Freundlich isotherm were close to 1 in most conditions suggesting that the hydrophobic partition is the major adsorption mechanism. In terms of SMZ, K d declined with increases in the pH. SPY has a pyridine group that is responsible for adsorption at high pH values, and thus, no significant trend between K d and pH was observed. At high pH ranges, SPY sorption deviated significantly from linear partitioning. The results suggested the sorption mechanism of these two sulfonamide antibiotics tended to be hydrophobic partitioning under most of the experimental conditions, especially at pH values lower than their corresponding pK a2. The fluorescence excitation emission matrix and dissolved organic carbon leaching test suggested composted manure has higher fulvic acid organics and that peat soil has higher humus-like organics. Small organic molecules showed stronger affinity toward sulfonamide antibiotics and cause the composted manure to exhibit higher sorption capacity. Overall, this study suggests that the chemical structure and properties of sulfonamides antibiotics and the type of organic matter in soils will greatly influence the fate and transport of these contaminants into the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. STRUCTURE AND CHARACTERISTICS OF PATENTED HIGH-CARBON WIRE

    Directory of Open Access Journals (Sweden)

    A. Ju. Borisenko

    2011-01-01

    Full Text Available The influence of bainite structure on mechanical characteristics of wire of steel 80 after patenting is studied. The quantity and structure state of bainite, providing high complex of mechanical characteristics of high-carbon wire, is determined.

  15. CARBON FIBER COMPOSITES IN HIGH VOLUME

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Charles David [ORNL; Das, Sujit [ORNL; Jeon, Dr. Saeil [Volvo Trucks North America

    2014-01-01

    Vehicle lightweighting represents one of several design approaches that automotive and heavy truck manufacturers are currently evaluating to improve fuel economy, lower emissions, and improve freight efficiency (tons-miles per gallon of fuel). With changes in fuel efficiency and environmental regulations in the area of transportation, the next decade will likely see considerable vehicle lightweighting throughout the ground transportation industry. Greater use of carbon fiber composites and light metals is a key component of that strategy. This paper examines the competition between candidate materials for lightweighting of heavy vehicles and passenger cars. A 53-component, 25 % mass reduction, body-in-white cost analysis is presented for each material class, highlighting the potential cost penalty for each kilogram of mass reduction and then comparing the various material options. Lastly, as the cost of carbon fiber is a major component of the elevated cost of carbon fiber composites, a brief look at the factors that influence that cost is presented.

  16. Using LUCAS topsoil database to estimate soil organic carbon content in local spectral libraries

    Science.gov (United States)

    Castaldi, Fabio; van Wesemael, Bas; Chabrillat, Sabine; Chartin, Caroline

    2017-04-01

    The quantification of the soil organic carbon (SOC) content over large areas is mandatory to obtain accurate soil characterization and classification, which can improve site specific management at local or regional scale exploiting the strong relationship between SOC and crop growth. The estimation of the SOC is not only important for agricultural purposes: in recent years, the increasing attention towards global warming highlighted the crucial role of the soil in the global carbon cycle. In this context, soil spectroscopy is a well consolidated and widespread method to estimate soil variables exploiting the interaction between chromophores and electromagnetic radiation. The importance of spectroscopy in soil science is reflected by the increasing number of large soil spectral libraries collected in the world. These large libraries contain soil samples derived from a consistent number of pedological regions and thus from different parent material and soil types; this heterogeneity entails, in turn, a large variability in terms of mineralogical and organic composition. In the light of the huge variability of the spectral responses to SOC content and composition, a rigorous classification process is necessary to subset large spectral libraries and to avoid the calibration of global models failing to predict local variation in SOC content. In this regard, this study proposes a method to subset the European LUCAS topsoil database into soil classes using a clustering analysis based on a large number of soil properties. The LUCAS database was chosen to apply a standardized multivariate calibration approach valid for large areas without the need for extensive field and laboratory work for calibration of local models. Seven soil classes were detected by the clustering analyses and the samples belonging to each class were used to calibrate specific partial least square regression (PLSR) models to estimate SOC content of three local libraries collected in Belgium (Loam belt

  17. How do changes in bulk soil organic carbon content affect carbon concentrations in individual soil particle fractions?

    Science.gov (United States)

    Yang, X. M.; Drury, C. F.; Reynolds, W. D.; Yang, J. Y.

    2016-06-01

    We test the common assumption that organic carbon (OC) storage occurs on sand-sized soil particles only after the OC storage capacity on silt- and clay-sized particles is saturated. Soil samples from a Brookston clay loam in Southwestern Ontario were analysed for the OC concentrations in bulk soil, and on the clay (<2 μm), silt (2-53 μm) and sand (53-2000 μm) particle size fractions. The OC concentrations in bulk soil ranged from 4.7 to 70.8 g C kg-1 soil. The OC concentrations on all three particle size fractions were significantly related to the OC concentration of bulk soil. However, OC concentration increased slowly toward an apparent maximum on silt and clay, but this maximum was far greater than the maximum predicted by established C sequestration models. In addition, significant increases in OC associated with sand occurred when the bulk soil OC concentration exceeded 30 g C kg-1, but this increase occurred when the OC concentration on silt + clay was still far below the predicted storage capacity for silt and clay fractions. Since the OC concentrations in all fractions of Brookston clay loam soil continued to increase with increasing C (bulk soil OC content) input, we concluded that the concept of OC storage capacity requires further investigation.

  18. Multi-component EPR spectra of coals with different carbon content

    Energy Technology Data Exchange (ETDEWEB)

    Pilawa, B.; Wieckowski, A.B.; Pietrzak, R.; Wachowska, H. [Polish Academy of Science, Gliwice (Poland). Inst. for Coal Chemistry

    2005-08-01

    EPR spectra of lignite 'Mequinenza' (Spain) (62.3 wt% C) and Polish orthocoking coal (87.8 wt% C) were compared. The spectra were superpositions of broad Gaussian, broad Lorentzian 1, and narrow Lorentzian 3 lines. Concentration of paramagnetic centers - mainly delocalized pi electrons responsible for narrow Lorentzian 3 lines increases with increase in carbon content in coal. Coal units with slow and fast spin-lattice relaxation processes exist in the two studied samples. Slow spin-lattice interactions occur in simple aromatic coal units with broad Gaussian and Lorentzian 1 lines. Fast spin-lattice relaxation processes are characteristic of large aromatic units with narrow Lorentzian 3 lines.

  19. Tritium- and carbon-14-contents of wines of different vintage from the northern and southern hemisphere

    International Nuclear Information System (INIS)

    Fischer, E.; Mueller, H.

    1980-01-01

    The carbon-14 and tritium radioactivity contents of up to 19 vintages of German and Southafrican wines were compared. A similar large dependence of the 14 C- and of the 3 H-activity in the German wine on the nuclear weapon tests of the years 1962/63 was found out. The radioactivity level is also 1977/78 still essentially higher than before 1950. The Southafrican wines have been influenced considerably less by nuclear explosions. The highest 3 H-values were found in the vintage 1963 of the German wine with 5910 pCi/litre and in the vintage 1964 of the Southafrican wine with 510 pCi/litre. (orig.) [de

  20. Gravel Mobility in a High Sand Content Riverbed

    Science.gov (United States)

    Haschenburger, J. K.

    2017-12-01

    In sand-gravel channels, sand may modify gravel transport by changing conditions of entrainment and promoting longer displacements or gravel may inhibit sand transport if concentrated into distinct deposits, which restrict sand supply with consequences for migrating bedform size or form. This study reports on gravel mobility in the lower San Antonio River, Texas, where gravel content in the bed material ranges from about 1% to more than 20%. Sediment transport observations were collected at three U.S. Geological Survey gauging stations by deploying a Helley-Smith sampler with a 0.2 mm mesh bag from which transport rates and mobile grain sizes were determined. The flow rates sampled translate into an annual exceedance expectation from 0.2% to 98%. Gravel transport rates are generally two orders of magnitude smaller than the rates of sand transport. However, the finest gravels are transported at rates on the same order of magnitude as the coarsest sands. At all sites, the 2 and 2.8 mm fractions are transported at the lowest flow rate sampled, suggesting mobility for at least 38% to as much as 98% of the year. Fractions as large as 8 mm are mobilized at flow rates that are expected between 25% and 53% of the year. The largest fractions captured in the sampling (16 to 32 mm) require flows closer to bankfull conditions that occur no more than 0.8% of the year. Results document that some gravel sizes can be frequently transported in low gradient riverbeds with high sand content.

  1. Carbon nanotubes for high-performance logic

    NARCIS (Netherlands)

    Chen, Zhihong; Philip Wong, H.-S.; Mitra, S.; Bol, A.A.; Peng, Lianmao; Hills, Gage; Thissen, N.F.W.

    2014-01-01

    Single-wall carbon nanotubes (CNTs) were discovered in 1993 and have been an area of intense research since then. They offer the right dimensions to explore material science and physical chemistry at the nanoscale and are the perfect system to study low-dimensional physics and transport. In the past

  2. High performance carbon–carbon composites

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    protected against oxidation either through matrix modification with Si, Zr, Hf etc. or by multilayer oxidation protection ... advanced composites for a wide range of applications. The majority of products still ... CVD is a very slow process and it takes months together to get dense carbon–carbon composites. Porous structures ...

  3. Fully Biodegradable Biocomposites with High Chicken Feather Content

    Directory of Open Access Journals (Sweden)

    Ibon Aranberri

    2017-11-01

    Full Text Available The aim of this work was to develop new biodegradable polymeric materials with high loadings of chicken feather (CF. In this study, the effect of CF concentration and the type of biodegradable matrix on the physical, mechanical and thermal properties of the biocomposites was investigated. The selected biopolymers were polylactic acid (PLA, polybutyrate adipate terephthalate (PBAT and a PLA/thermoplastic copolyester blend. The studied biocomposites were manufactured with a torque rheometer having a CF content of 50 and 60 wt %. Due to the low tensile strength of CFs, the resulting materials were penalized in terms of mechanical properties. However, high-loading CF biocomposites resulted in lightweight and thermal-insulating materials when compared with neat bioplastics. Additionally, the adhesion between CFs and the PLA matrix was also investigated and a significant improvement of the wettability of the feathers was obtained with the alkali treatment of the CFs and the addition of a plasticizer like polyethylene glycol (PEG. Considering all the properties, these 100% fully biodegradable biocomposites could be adequate for panel components, flooring or building materials as an alternative to wood–plastic composites, contributing to the valorisation of chicken feather waste as a renewable material.

  4. Development of automatic image analysis methods for high-throughput and high-content screening

    NARCIS (Netherlands)

    Di, Zi

    2013-01-01

    This thesis focuses on the development of image analysis methods for ultra-high content analysis of high-throughput screens where cellular phenotype responses to various genetic or chemical perturbations that are under investigation. Our primary goal is to deliver efficient and robust image analysis

  5. Fructose content and composition of commercial HFCS-sweetened carbonated beverages.

    Science.gov (United States)

    White, J S; Hobbs, L J; Fernandez, S

    2015-01-01

    The obesigenic and related health effects of caloric sweeteners are subjects of much current research. Consumers can properly adjust their diets to conform to nutritional recommendations only if the sugars composition of foods and beverages is accurately measured and reported, a matter of recent concern. We tested the hypothesis that high-fructose corn syrup (HFCS) used in commercial carbonated beverages conforms to commonly assumed fructose percentages and industry technical specifications, and fulfills beverage product label regulations and Food Chemicals Codex-stipulated standards. A high-pressure liquid chromatography method was developed and verified for analysis of sugars in carbonated beverages sweetened with HFCS-55. The method was used to measure percent fructose in three carbonated beverage categories. Method verification was demonstrated by acceptable linearity (R(2)>0.99), accuracy (94-104% recovery) and precision (RSD canned and bottled products and met the US Federal requirements for nutritional labeling and nutrient claims. Prior concerns about composition were likely owing to use of improper and unverified methodology.

  6. The effects of carbon nano filaments (CNT and CNF) doping on high temperature superconductors Y-123

    International Nuclear Information System (INIS)

    Dadras, S.; Daadmehr, V.

    2007-01-01

    Full text: This paper is based on the effects of carbon nano filaments (carbon nano tubes and carbon nano fibers) doping on Y-123 studies. We synthesized Y-123 with different contents of CNT and CNF doping. The samples were prepared from powders of Y 2 O 3 , BaCO 3 and Cu O by the solid state reaction. After calcination in air, we mixed Y-123 powder with different percentage of carbon nano filaments weight, produced by the CVD method. For obtaining more homogenous mixing, we have suspended it in an organic solvent with an ultrasonic mixer to prevent agglomeration of CNT. The CNT-Y-123 powder was dried afterwards, and pressed as pellet samples, in about 1mm thick, 10mm diameter, and 1gr weight, and sintered in oxygen atmosphere. We tried to find the transport effects on CNT and CNF doping in 123 systems. The strong coupling between grains in CNT doped samples caused the flow of inter-granular currents. Therefore the presence of CNT in high temperature superconductor samples increases the critical current density. Among various carbon precursors, carbon nano tubes (CNT) are very interesting because of their nano meter diameter which may make them as effective pinning centers, compared to the ordinary carbon. The carbon nano tubes are functioning like columnar defects produced by heavy-ion irradiation. Nano phase particles or aggregates embodied in the superconductor matrix can pin the flux lines effectively and enhance the intra-grain transport critical current density in high applied magnetic fields. Nano phase size particles in the size range of about 5-10 nm can be used as flux pinning centers for low field applications. The effects of carbon and carbon dioxide in Y-123 were studied by several groups, but none of them argued the effects of carbon nano tubes doping on Y-123. Uno et al. found that Jc was related to the carbon concentration, but they showed that Tc value and other physical properties did not change. In carbon doped Y-123 samples, Tc decreases with

  7. New technology for carbon dioxide at high pressure

    International Nuclear Information System (INIS)

    Hassina, Bazaze; Raouf, Zehioua; Menial, A. H.

    2006-01-01

    Carbon dioxide has long been the nemesis of environmentalists because of its role in global warming, but under just the right conditions-namely, high pressure and high temperature its one of nature's best and most environmentally benign solvents. Decaf-coffee lovers, for instance, benefit from its ability to remove caffeine from coffee beans.During the last few years, carbon dioxide has also made inroads in the dry-cleaning industry, providing a safe cleaning alternative to the chemical perchloroethylene. But it's on the high-tech front that carbon dioxide may make its biggest impact. T here are huge opportunities. Scientists have known for more than a century that at 75 times atmospheric pressure and 31 degree centigrade, carbon dioxide goes into and odd state that chemists called s upercritical . What's interesting to industry is that supercritical carbon dioxide may be an enabling technology for going to smaller dimensions.(Author)

  8. Enhanced cycle stability of micro-sized Si/C anode material with low carbon content fabricated via spray drying and in situ carbonization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dingsheng; Gao, Mingxia, E-mail: gaomx@zju.edu.cn; Pan, Hongge; Liu, Yongfeng; Wang, Junhua; Li, Shouquan; Ge, Hongwei

    2014-08-01

    Highlights: • Micro-sized Si/C composites were fabricated via. spray drying and carbonization. • Multi-morphology carbon was formed in the Si/C composites. • Si/C composite with 5.6 wt.% C provides significant improved cycling stability. • Multi-morphology carbon plays effective role in improving the electrochemical property. • The method provides potential for mass production of superior Si-based anode materials. - Abstract: Micro-sized Si/C composites with in situ introduced carbon of multi-morphology were fabricated via spray drying a suspension of commercial micro-sized Si and citric acid followed by a carbonization. Different ratios of Si to citric acid were used to optimize the composition and structure of the composites and thus the electrochemical performance. Carbon flakes including crooked and flat ones were well dispersed in between the Si particles, forming Si/C composites. Floc-like carbon layers and carbon fragments were also found to cover partially the Si particles. The Si/C composite with a low carbon content of 5.6 wt.% provides an initial reversible capacity of 2700 mA h/g and a capacity of 1860 mA h/g after 60 cycles at a current density of 100 mA/g as anode material for lithium-ion batteries (LIBs), which are much higher than those of pristine Si and the Si/C composites with higher carbon content. The mechanism of the enhancement of electrochemical performance of the micro-sized Si/C composite is discussed. The fabrication method and the structure design of the composites offer valuable potential in developing adaptable Si-based anode materials for industrial applications.

  9. High purity samarium oxide from mixed rare earth carbonates

    International Nuclear Information System (INIS)

    Queiroz, Carlos A. da S.; Seneda, Jose A.; Vasconcellos, Mari E. de; Pedreira Filho, Walter dos R.

    2013-01-01

    A simple and economical chemical process for the production of highly pure samarium oxides is discussed. The raw material, which was used in the form of rare earth carbonates was produced industrially from the chemical treatment of Brazilian monazite. Ion exchange chromatography was performed using a strong cationic resin that is typically employed in water treatment processes to fractionate rare earth elements (REE) without the use of retention ions. Under these conditions, 99.9% pure Sm 2 O 3 was eluted using the ammonium salt of ethylenediaminetetraacetic acid (EDTA) at a controlled pH. The EDTA-samarium complex was separated from EDTA and then precipitated as oxalate and fired to samarium oxide. Molecular absorption spectrophotometry was used to monitor the samarium content during the proposed process, and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the samarium oxide. Typical samarium oxide obtained from the proposed procedure contained the following contaminants in micrograms per gram: Sc (20.90); Y (11.80); La (8.4); Ce (4.3); Pr (2.5); Nd (5.1); Eu (94); Gd (114); Tb (3.6); Dy (2.5), Ho (2.3); Er (3.0); Tm (2.3); Yb (38,2); Lu (25.6). The high-purity samarium oxides produced in the present study can be used as an alternative to imported products in research and development applications. (author)

  10. Electrical and Self-Sensing Properties of Ultra-High-Performance Fiber-Reinforced Concrete with Carbon Nanotubes

    OpenAIRE

    You, Ilhwan; Yoo, Doo-Yeol; Kim, Soonho; Kim, Min-Jae; Zi, Goangseup

    2017-01-01

    This study examined the electrical and self-sensing capacities of ultra-high-performance fiber-reinforced concrete (UHPFRC) with and without carbon nanotubes (CNTs). For this, the effects of steel fiber content, orientation, and pore water content on the electrical and piezoresistive properties of UHPFRC without CNTs were first evaluated. Then, the effect of CNT content on the self-sensing capacities of UHPFRC under compression and flexure was investigated. Test results indicated that higher ...

  11. The soil organic carbon content of anthropogenically altered organic soils effects the dissolved organic matter quality, but not the dissolved organic carbon concentrations

    Science.gov (United States)

    Frank, Stefan; Tiemeyer, Bärbel; Bechtold, Michel; Lücke, Andreas; Bol, Roland

    2016-04-01

    Dissolved organic carbon (DOC) is an important link between terrestrial and aquatic ecosystems. This is especially true for peatlands which usually show high concentrations of DOC due to the high stocks of soil organic carbon (SOC). Most previous studies found that DOC concentrations in the soil solution depend on the SOC content. Thus, one would expect low DOC concentrations in peatlands which have anthropogenically been altered by mixing with sand. Here, we want to show the effect of SOC and groundwater level on the quantity and quality of the dissolved organic matter (DOM). Three sampling sites were installed in a strongly disturbed bog. Two sites differ in SOC (Site A: 48%, Site B: 9%) but show the same mean annual groundwater level of 15 and 18 cm below ground, respectively. The SOC content of site C (11%) is similar to Site B, but the groundwater level is much lower (-31 cm) than at the other two sites. All sites have a similar depth of the organic horizon (30 cm) and the same land-use (low-intensity sheep grazing). Over two years, the soil solution was sampled bi-weekly in three depths (15, 30 and 60 cm) and three replicates. All samples were analyzed for DOC and selected samples for dissolved organic nitrogen (DON) and delta-13C and delta-15N. Despite differences in SOC and groundwater level, DOC concentrations did not differ significantly (A: 192 ± 62 mg/L, B: 163 ± 55 mg/L and C: 191 ± 97 mg/L). At all sites, DOC concentrations exceed typical values for peatlands by far and emphasize the relevance even of strongly disturbed organic soils for DOC losses. Individual DOC concentrations were controlled by the temperature and the groundwater level over the preceding weeks. Differences in DOM quality were clearer. At site B with a low SOC content, the DOC:DON ratio of the soil solution equals the soil's C:N ratio, but the DOC:DON ratio is much higher than the C:N ratio at site A. In all cases, the DOC:DON ratio strongly correlates with delta-13C. There is no

  12. Respiratory Effects of Inhaled Single-Walled Carbon Nanotubes: The Role of Particle Morphology and Iron Content

    Science.gov (United States)

    Madl, Amy Kathleen

    Nanotechnology provides promise for significant advancements in a number of different fields including imaging, electronics, and therapeutics. With worldwide production of carbon nanotubes (CNTs) exceeding over 500 metric tons annually and industry growth expecting to double over the next 5 yr, there are concerns our understanding of the hazards of these nanomaterials may not be keeping pace with market demand. The physicochemical properties of CNTs may delineate the key features that determine either toxicity or biocompatibility and assist in evaluating the potential health risks posed in industrial and consumer product settings. We hypothesized that the iron content and morphology of inhaled single-walled carbon nanotubes (SWCNTs) influences the extent of cellular injury and alters homeostasis in the lung. To address this hypothesis, (1) an aerosol system was developed to deliver carbon-based nanomaterials in a manner of exposure that is physiologically and environmentally relevant (e.g., inhalation), (2) acute (1 d) and subacute (10 d) nose-only inhalation studies to a well-characterized aerosol of iron-containing (FeSWCNT) versus cleaned (iron removed, cSWCNTs) SWCNTs were conducted to evaluate the time-course patterns of possible injury through measurement of markers of cytotoxicity, inflammation, and cellular remodeling/homeostasis, and (3) the effects of SWCNTs were compared to other well-studied materials (e.g. non-fibrous, low-iron content ultrafine carbon black and fibrous, high-iron content, highly persistent, durable and potent carcinogen crocidolite) to offer insights into the relative toxicity of these nanomaterials as well as the possible mechanisms by which the effects occur. Rats (SD) were exposed to either aerosolized SWCNTs (raw FeSWCNT or purified cSWCNT), carbon black (CB), crocidolite, or fresh air via nose-only inhalation. Markers of inflammation and cytotoxicity in lung lavage, mucin in different airway generations, and collagen in the

  13. Design and Implementation of High Performance Content-Addressable Memories.

    Science.gov (United States)

    1985-12-01

    content addressability and two basic implementations of content addressing. The need and application of hardware CAM is presented to motivate the " topic...3r Pass 4th Ps4 Pass Figure 2.15 Maximum SearchUsing All-Parallel CAM - left-most position (the most significant bit) and the other IF bits are zeros

  14. Carbon-carbon composite and copper-composite bond damages for high flux component controlled fusion

    International Nuclear Information System (INIS)

    Chevet, G.

    2010-01-01

    Plasma facing components constitute the first wall in contact with plasma in fusion machines such as Tore Supra and ITER. These components have to sustain high heat flux and consequently elevated temperatures. They are made up of an armour material, the carbon-carbon composite, a heat sink structure material, the copper chromium zirconium, and a material, the OFHC copper, which is used as a compliant layer between the carbon-carbon composite and the copper chromium zirconium. Using different materials leads to the apparition of strong residual stresses during manufacturing, because of the thermal expansion mismatch between the materials, and compromises the lasting operation of fusion machines as damage which appeared during manufacturing may propagate. The objective of this study is to understand the damage mechanisms of the carbon-carbon composite and the composite-copper bond under solicitations that plasma facing components may suffer during their life. The mechanical behaviours of carbon-carbon composite and composite-copper bond were studied in order to define the most suitable models to describe these behaviours. With these models, thermomechanical calculations were performed on plasma facing components with the finite element code Cast3M. The manufacturing of the components induces high stresses which damage the carbon-carbon composite and the composite-copper bond. The damage propagates during the cooling down to room temperature and not under heat flux. Alternative geometries for the plasma facing components were studied to reduce damage. The relation between the damage of the carbon-carbon composite and its thermal conductivity was also demonstrated. (author) [fr

  15. Activated carbon derived from chitosan as air cathode catalyst for high performance in microbial fuel cells

    Science.gov (United States)

    Liu, Yi; Zhao, Yong; Li, Kexun; Wang, Zhong; Tian, Pei; Liu, Di; Yang, Tingting; Wang, Junjie

    2018-02-01

    Chitosan with rich of nitrogen is used as carbon precursor to synthesis activated carbon through directly heating method in this study. The obtained carbon is activated by different amount of KOH at different temperatures, and then prepared as air cathodes for microbial fuel cells. Carbon sample treated with double amount of KOH at 850 °C exhibits maximum power density (1435 ± 46 mW m-2), 1.01 times improved, which ascribes to the highest total surface area, moderate micropore and mesoporous structure and the introduction of nitrogen. The electrochemical impedance spectroscopy and powder resistivity state that carbon treated with double amount of KOH at 850 °C possesses lower resistance. The other electrochemical measurements demonstrate that the best kinetic activity make the above treated sample to show the best oxygen reduction reaction activity. Besides, the degree of graphitization of samples increases with the activated temperature increasing, which is tested by Raman. According to elemental analysis and X-ray photoelectron spectroscopy, all chitosan samples are nitrogen-doped carbon, and high content nitrogen (pyridinic-N) improves the electrochemical activity of carbon treated with KOH at 850 °C. Thus, carbon materials derived from chitosan would be an optimized catalyst for oxygen reduction reaction in microbial fuel cell.

  16. Identification of Detrital Carbonate in East Cepu High

    Science.gov (United States)

    Sari, R.; Andika, I. K.; Haris, A.; Miftah, A.

    2018-03-01

    East Cepu High is a part of horst – graben series which formed by extensional tectonic processes during Paleogene in North East Java Basin. Due to excellent paleogeography position, the carbonate build-up was growth very well and as the main reservoir in East Cepu High. Sea level change have important factor to provide variation of facies in each carbonate buildup, one of emerging facies is detrital carbonate. Detrital carbonate indicated by onlap horizon featured with carbonate build up body. Based on paleogeography, fluctuation of sea level change and sediment source, detrital carbonate formed in leeward area in lowstand or highstand phases. Distinguish between detrital carbonate facies with other facies, advanced seismic processing performed by using continuous wavelet transform (CWT) and seismic inversion. CWT is one method of spectral decomposition used to find the frequency that represent a facies. The result from seismic inversion will support the interpretation for facies distribution. As the result, seismic data which have interval frequency 10 – 45 Hz and Acoustic Impedance (AI) value above 35000 (from cross plot between acoustic impedance and gamma ray) can be interpreted as detrital carbonate. Based on seismic interpretation, detrital carbonate facies distributed along leeward area with geometrical spreading. The lateral facies change from detrital carbonate to shale was identified which causing this facies become potential as hydrocarbon reservoir with stratigraphic trap. Based on the earlier studies, North East Java Basin have a strong hydrocarbon migration to fill the reservoir, therefore the detrital carbonate have high chance to be a new hydrocarbon prospect in this area.

  17. Effects of carbon content and chromium segregation on creep rupture properties of low carbon and medium nitrogen type 316 stainless steel

    International Nuclear Information System (INIS)

    Nakazawa, Takanori; Fujita, Nobuhiro; Kimura, Hidetaka; Komatsu, Hajime; Kotoh, Hiroyuki; Kaguchi, Hitoshi.

    1997-01-01

    The creep rupture properties of type 316 stainless steels containing 0.005-0.022%C and 0.07%N have been investigated at 550degC and 600degC from the aspect of the grain boundary carbide precipitation which was changed with carbon content and chromium segregation. A small amount of carbide precipitated on grain boundaries during creep, because the solubility limit of the carbide is less than 0.005%. The creep rupture ductility of this steel increased with the reduction of carbon content from 0.010% to 0.005% while it decreased with increasing carbon content from 0.010% to 0.020%. Since the amount of grain boundary carbide decreased with reducing carbon content, the increase in ductility was due to the suppression of grain boundary embrittlement caused by the carbide. The creep rupture ductility of this steel was also improved by reducing chromium segregation. This behavior was attributed to the change in carbide morphology from concentrated type to dispersed one, which reduced the grain boundary embrittlement. (author)

  18. Highly effective catalytic peroxymonosulfate activation on N-doped mesoporous carbon for o-phenylphenol degradation.

    Science.gov (United States)

    Hou, Jifei; Yang, Shasha; Wan, Haiqin; Fu, Heyun; Qu, Xiaolei; Xu, Zhaoyi; Zheng, Shourong

    2018-04-01

    As a broad-spectrum preservative, toxic o-phenylphenol (OPP) was frequently detected in aquatic environments. In this study, N-doped mesoporous carbon was prepared by a hard template method using different nitrogen precursors and carbonization temperatures (i.e., 700, 850 and 1000 °C), and was used to activate peroxymonosulfate (PMS) for OPP degradation. For comparison, mesoporous carbon (CMK-3) was also prepared. Characterization results showed that the N-doped mesoporous carbon samples prepared under different conditions were perfect replica of their template. In comparison with ethylenediamine (EDA) and dicyandiamide (DCDA) as the precursors, N-doped mesoporous carbon prepared using EDA and carbon tetrachloride as the precursors displayed a higher catalytic activity for OPP degradation. Increasing carbonization temperature of N-doped mesoporous carbon led to decreased N content and increased graphitic N content at the expense of pyridinic and pyrrolic N. Electron paramagnetic resonance (EPR) analysis showed that PMS activation on N-doped mesoporous carbon resulted in highly active species and singlet oxygen, and catalytic PMS activation for OPP degradation followed a combined radical and nonradical reaction mechanism. Increasing PMS concentration enhanced OPP degradation, while OPP degradation rate was independent on initial OPP concentration. Furthermore, the dependency of OPP degradation on PMS concentration followed the Langmuir-Hinshelwood model, reflecting that the activation of adsorbed PMS was the rate controlling step. Based on the analysis by time-of-flight mass spectrometry, the degradation pathway of OPP was proposed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Initial Soil Organic Matter Content Influences the Storage and Turnover of Litter-, Root- and Soil Carbon in Grasslands

    Science.gov (United States)

    Liu, L.; Xu, S.; Li, P.; Sayer, E. J.

    2017-12-01

    Grassland degradation is a worldwide problem that often leads to substantial loss of soil organic matter (SOM). Understanding how SOM content influences the stabilization of plant carbon (C) to form soil C is important to evaluate the potential of degraded grasslands to sequester additional C. We conducted a greenhouse experiment using C3 soils with six levels of SOM content and planted the C4 grass Cleistogenes squarrosa and/or added its litter to investigate how SOM content regulates the storage of new soil C derived from litter and roots, the decomposition of extant soil C, and the formation of soil aggregates. We found that microbial biomass carbon (MBC) increased with SOM content, and increased the mineralization of litter C. Both litter addition and planted treatments increased the amount of new C inputs to soil. However, litter addition had no significant impacts on the mineralization of extant soil C, but the presence of living roots significantly accelerated it. Thus, by the end of the experiment, soil C content was significantly higher in the litter addition treatments, but was not affected by planted treatments. The soil macroaggregate fraction increased with SOM content and was positively related to MBC. Overall, our study suggests that as SOM content increases, plant growth and soil microbes become more active, which allows microbes to process more plant-derived C and increases new soil C formation. The interactions between SOM content and plant C inputs should be considered when evaluating soil C turnover in degraded grasslands.

  20. Disentangling the counteracting effects of water content and carbon mass on zooplankton growth

    DEFF Research Database (Denmark)

    Mcconville, Kristian; Atkinson, Angus; Fileman, Elaine S.

    2017-01-01

    Zooplankton vary widely in carbon percentage (carbon mass as a percentage of wet mass), but are often described as either gelatinous or non-gelatinous. Here we update datasets of carbon percentage and growth rate to investigate whether carbon percentage is a continuous trait, and whether its incl...

  1. The preparation and characterization of CNx film with high nitrogen content by cathode electrodeposition

    International Nuclear Information System (INIS)

    Zhang, J.-T.; Cao, C.-B.; Lv Qiang; Li Chao; Zhu Hesun

    2003-01-01

    CN x thin film with high nitrogen content was prepared on ITO conductive glass substrates by cathode electrodeposition, using dicyandiamide (C 2 H 4 N 4 ) in acetone as precursors. The surface morphologies, atomic bonding state, and chemical composition were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectroscopy. The CN x particles got nanometer level with the average size of 80 nm. The maximum value of the N/C atomic ratio was more than 1. Carbon and nitrogen existed mainly in the form of tetrahedral C-N bonds, with a few C-N bonds. From UV-Vis absorption spectrum, we found that during near-ultraviolet area the deposited CN x films appeared nonlinear optical absorption phenomena, and the ultraviolet light (200-280 nm) could be transmitted. The electrical resistivities of the films were in the range of 10 12 -10 16 Ω cm

  2. Dwarf mutant of Papaver somniferum with high morphine content

    International Nuclear Information System (INIS)

    Chauhan, S.P.; Patra, N.K.; Srivastava, H.K.

    1987-01-01

    Opium poppy, Papaver somniferum L. is an important medicinal plant known for its morphine, codeine, and thebaine alkaloids. This Institute had earlier released two latex opium yielding poppy varieties, Shyama and Shweta, which are now cultivated by the farmers under the supervision of the Narcotic Department of the Government of India. However, both these varieties became susceptible to downy mildew (Peronospora arborescens). Lodging due to heavy capsule weight is another problem affecting latex yield. With these problems in mind, we undertook mutation breeding on the above mentioned two varieties employing gamma rays (5 kR, 15 kR, 20 kR) and EMS (0.2%, 0.4%, 0.6%) and combined mutagens (5 kR + 0.2% EMS, 5 kR + 0.4% EMS and 5 kR + 0.6% EMS). M 1 from the treated seeds (405 plants) was raised in winter 1984-85. M 2 generation of 13,500 plants (i.e. 270 M 1 progenies x 50 plants) was raised in winter 1985/86. A dwarf mutant with high morphine content was identified in M 2 from the variety Shweta treated with 5 kR + 0.4% EMS. The mutant differs by its dwarf stature, compact leaf arrangements, multilocular capsules, increased capsule number, and small capsule size. The mutant is under testing for its superior morphine production. It may be used as dwarf gene source in hybridization for improving lodging resistance. This mutant is a novel type, which was not available in our germplasm collection

  3. Functional differences in the allometry of the water, carbon and nitrogen content of gelatinous organisms

    KAUST Repository

    Molina-Ramírez, Axayacatl

    2015-05-19

    We have supplemented available, concurrent measurements of fresh weight (W, g) and body carbon (C, g) (46 individuals, 14 species) and nitrogen (N, g) (11 individuals, 9 species) of marine gelatinous animals with data obtained during the global ocean MALASPINA 2010 Expedition (totalling 267 individuals and 33 species for the W versus C data; totalling 232 individuals and 31 species for the N versus C data). We then used those data to test the allometric properties of the W versus C and N versus C relationships. Overall, gelatinous organisms contain 1.13 ± 1.57% of C (by weight, mean ± SD) in their bodies and show a C:N of 4.56 ± 2.46, respectively, although estimations can be improved by using separate conversion coefficients for the carnivores and the filter feeders. Reduced major axis regression indicates that W increases isometrically with C in the carnivores (cnidarians and ctenophores), implying that their water content can be described by a single conversion coefficient of 173.78 gW(g C)-1, or a C content of 1.17 ± 1.90% by weight, although there is much variability due to the existence of carbon-dense species. In contrast, W increases more rapidly than C in the filter feeders (salps and doliolids), according to a power relationship W = 446.68C1.54. This exponent is not significantly different from 1.2, which is consistent with the idea that the watery bodies of gelatinous animals represent an evolutionary response towards increasing food capture surfaces, i.e. a bottom-up rather than a top-down mechanism. Thus, the available evidence negates a bottom-up mechanism in the carnivores, but supports it in the filter feeders. Last, N increases isometrically with C in both carnivores and filter feeders with C:N ratios of 3.89 ± 1.34 and 4.38 ± 1.21, respectively. These values are similar to those of compact, non-gelatinous organisms and reflect a predominantly herbivorous diet in the filter feeders, which is confirmed by a difference of one trophic level

  4. Functional differences in the allometry of the water, carbon and nitrogen content of gelatinous organisms

    KAUST Repository

    Molina-Ramí rez, Axayacatl; Cá ceres, Carlos; Romero-Romero, Sonia; Bueno, Juan; Gonzá lez-Gordillo, J. Ignacio; Irigoien, Xabier; Sostres, Jorge; Bode, Antonio; Mompeá n, Carmen; Ferná ndez Puelles, Mariluz; Echevarria, Fidel; Duarte, Carlos M.; Acuñ a, José Luis

    2015-01-01

    We have supplemented available, concurrent measurements of fresh weight (W, g) and body carbon (C, g) (46 individuals, 14 species) and nitrogen (N, g) (11 individuals, 9 species) of marine gelatinous animals with data obtained during the global ocean MALASPINA 2010 Expedition (totalling 267 individuals and 33 species for the W versus C data; totalling 232 individuals and 31 species for the N versus C data). We then used those data to test the allometric properties of the W versus C and N versus C relationships. Overall, gelatinous organisms contain 1.13 ± 1.57% of C (by weight, mean ± SD) in their bodies and show a C:N of 4.56 ± 2.46, respectively, although estimations can be improved by using separate conversion coefficients for the carnivores and the filter feeders. Reduced major axis regression indicates that W increases isometrically with C in the carnivores (cnidarians and ctenophores), implying that their water content can be described by a single conversion coefficient of 173.78 gW(g C)-1, or a C content of 1.17 ± 1.90% by weight, although there is much variability due to the existence of carbon-dense species. In contrast, W increases more rapidly than C in the filter feeders (salps and doliolids), according to a power relationship W = 446.68C1.54. This exponent is not significantly different from 1.2, which is consistent with the idea that the watery bodies of gelatinous animals represent an evolutionary response towards increasing food capture surfaces, i.e. a bottom-up rather than a top-down mechanism. Thus, the available evidence negates a bottom-up mechanism in the carnivores, but supports it in the filter feeders. Last, N increases isometrically with C in both carnivores and filter feeders with C:N ratios of 3.89 ± 1.34 and 4.38 ± 1.21, respectively. These values are similar to those of compact, non-gelatinous organisms and reflect a predominantly herbivorous diet in the filter feeders, which is confirmed by a difference of one trophic level

  5. Broccoli-like porous carbon nitride from ZIF-8 and melamine for high performance supercapacitors

    Science.gov (United States)

    Cai, Chenglong; Zou, Yongjin; Xiang, Cuili; Chu, Hailiang; Qiu, Shujun; Sui, Qingli; Xu, Fen; Sun, Lixian; Shah, Afzal

    2018-05-01

    Broccoli-like porous carbon nitride is synthesized by simple one-step carbonization of a composite comprising a Zn-based zeolitic imidazolate framework (ZIF-8) and melamine. The introduction of melamine into the ZIF-8 framework not only increases the N content of the composite and the surface area of the carbonization product, but also induces the formation of a flower-like structure. The carbon obtained from the ZIF-8/melamine composite by the proposed carbonization process at a temperature of 800 °C (ZM-C-800) is found to have a unique three-dimensional broccoli-like shape, a nanoscale size, and an extremely high doping N content (28.3 at.%). These properties substantially improve the electrochemical performance of ZM-C-800, as represented by a high specific capacitance of 359.1 F g-1 at a current density of 1 A g-1, much higher than that of ZIF-8. Furthermore, a symmetric supercapacitor fabricated with two ZM-C-800 electrodes exhibits a power density of 498.5 W kg-1 for an energy density of 11.4 Wh kg-1. This indicates the strong potential of ZM-C-800 for use in the fabrication of energy storage devices.

  6. High-carbon chromium steel resistance to small plastic deformation

    International Nuclear Information System (INIS)

    Gajduchenya, V.F.; Madyanov, S.A.; Apaev, B.A.; Kirillov, Yu.V.; Sokolov, L.D.

    1978-01-01

    The phase composition of a steel with 1.08% C and 2.1% Cr, and the variation in the level of microstresses in the matrix as related to the annealing temperature in the range of 400-600 deg C and in the applied compression stress were investigated. To study the phase composition, and chromium content in the α-solution and the carbide phases, magnetic, chemical, and X-ray spectrum analyses were carried out. The change in the level of microstresses was determined roentgenographically. During the stress relaxation test at temperatures of 20-180 deg C, the mechanism of plastic deformation near the yield point was investigated. It is shown that three dislocation mechanisms operate in high-carbon chromium steel under the conditions at hand: overcoming the Pierls-Nabarro barriers by the dislocations, overcoming the stress fields of coherent carbide particles by dislocations, and circumvention of second-phase particles by dislocations. The dependence of the realization of the different plastic deformation mechanisms on the number of carbide particles and the chromium concentration in the matrix was established. The thermally activated nature of the motion of the dislocations under conditions of stress relaxation at an elevated temperature is noted

  7. Hydrothermal Synthesis and Biocompatibility Study of Highly Crystalline Carbonated Hydroxyapatite Nanorods

    Science.gov (United States)

    Xue, Caibao; Chen, Yingzhi; Huang, Yongzhuo; Zhu, Peizhi

    2015-08-01

    Highly crystalline carbonated hydroxyapatite (CHA) nanorods with different carbonate contents were synthesized by a novel hydrothermal method. The crystallinity and chemical structure of synthesized nanorods were studied by Fourier transform infrared spectroscopy (FTIR), X-ray photo-electronic spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM). The biocompatibility of synthesized CHA nanorods was evaluated by cell viability and alkaline phosphatase (ALP) activity of MG-63 cell line. The biocompatibility evaluation results show that these CHA nanorods are biologically active apatites and potentially promising bone-substitute biomaterials for orthopedic application.

  8. Effect of carbon content on formation of bimodal microstructure and mechanical properties of low-carbon steels subjected to heavy-reduction single-pass hot/warm deformation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyung-Won, E-mail: wonipark@iis.u-tokyo.ac.jp [Graduate School of Engineering, The University of Tokyo, Komaba 4-6-1, Meguro-ku 153-8505, Tokyo (Japan); Yanagimoto, Jun [Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku 153-8505, Tokyo (Japan)

    2014-06-01

    A compression test simulating heavy-reduction single-pass rolling was conducted to investigate the microstructural evolution based on the formation of a bimodal structure and the mechanical properties of 0.01% and 0.1% carbon steels and niobium steel. When thermomechanical processing was conducted near and above the critical transformation temperature (A{sub c3}), microstructures of all steels were significantly refined and consisted of equiaxed grains without elongated grains. Nevertheless, these microstructures showed weak or no formation of the bimodal structure or coarse grains with decreasing carbon content, while they showed bimodal structure formation when 0.2% carbon steel was used in our previous research. The average grain size of Nb steel was about 2 μm and its microstructure was uniformly refined. These may be attributed to a decrease in the number of nucleation sites with decreasing carbon content in low-carbon steels and the occurrence of nucleation at grain boundaries as well as in grain interiors in Nb steel during processing. Mechanical properties of all steels deformed above the critical transformation temperature exhibited high performance characteristics with superior strength and marked elongation. Their fractographs indicated ductile fracture, which was revealed by SEM observation after a tensile test.

  9. Biomass, organic carbon and calorific content of zooplankton from the Arabian Sea off Central West coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Krishnakumari, L.; Nair, V.R.

    Organic carbon content and calorific values of zooplankton varied from 18.35 to 32.49% (av. 27.8%) and from 2.56 to 4.71 k cal. g-1 dry wt (av. 3.99) respectively. Areawise off Gujarat sustained higher standing stock of zooplankton (77.18 mg m-3...

  10. Glacial to interglacial contrast in the calcium carbonate content and influence of Indus discharge in two eastern Arabian sea cores

    Digital Repository Service at National Institute of Oceanography (India)

    Naidu, P.D.

    -74. Muller, G. and Gastner, M., 1971. The Karbonat Bombe a simple device for the determination of carbonate content in marine sediments, soil and other materials. Neues Jahrb. Mineral. Monat sh., pp. 466-469. Nair, R.R., Ittekkot, V., Manganani, S...

  11. Uncovering the Driving Factors of Carbon Emissions in an Investment Allocation Model of China’s High-Carbon and Low-Carbon Energy

    Directory of Open Access Journals (Sweden)

    Shumin Jiang

    2017-06-01

    Full Text Available In the view of long-term comprehensive development, the concept of low-carbon economy has long been a concern. In this paper, we build a pure energy-economic system and explore the exact influencing factors in the investment allocation of high-carbon and low-carbon energy with the purpose of mitigating carbon dioxide in the atmosphere. The dynamic analysis shows that the model that we built is applicable for the current market situation and the way we adjust the investments of high-carbon and low-carbon energy are conductive to carbon abatement in the atmosphere. On the basis of the stability analysis and numerical simulation, some strategies are given to decrease the carbon dioxide in the atmosphere. The results show that the social consumption and public consumption behavior are the most important factors responsible for the variation in the atmospheric carbon dioxide. The cleanliness of high carbon presents an obvious mitigating effect on carbon in the atmosphere and the effect of marginal profit of high-carbon energy is the weakest. In addition, enhancing marginal profit, return on investment and investment share of low-carbon energy are beneficial to reduce carbon dioxide in the atmosphere, while a return on investment of high-carbon energy increasing is the detriment of the carbon dioxide in the atmosphere. Finally, we provide carbon mitigation effort by considering both economic development and carbon abatement for policymakers to achieve a desirable emission-reduction effect.

  12. Rust Layer Formed on Low Carbon Weathering Steels with Different Mn, Ni Contents in Environment Containing Chloride Ions

    Directory of Open Access Journals (Sweden)

    Gui-qin FU

    2016-11-01

    Full Text Available The rusting evolution of low carbon weathering steels with different Mn, Ni contents under a simulated environment containing chloride ions has been investigated to clarify the correlation between Mn, Ni and the rust formed on steels. The results show that Mn contents have little impact on corrosion kinetics of experimental steels. Content increase of Ni both enhances the anti-corrosion performance of steel substrate and the rust. Increasing Ni content is beneficial to forming compact rust. Semi-quantitative XRD phase analysis shows that the quantity ratio of α/γ*(α-FeOOH/(γ-FeOOH+Fe3O4 decreases as Mn content increases but it increases as Ni content increases. Ni enhances rust layer stability but Mn content exceeding 1.06 wt.% is disadvantageous for rust layer stability. The content increase of Mn does not significantly alter the parameters of the polarization curve. However, as Ni contents increases, Ecorr has shifted to the positive along with decreased icorr values indicating smaller corrosion rate especially as Ni content increases from 0.42 wt.% to 1.50 wt.%.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12844

  13. High Volume Fraction Carbon Nanotube Composites for Aerospace Applications

    Science.gov (United States)

    Siochi, E. J.; Kim, J.-W.; Sauti, G.; Cano, R. J.; Wincheski, R. A.; Ratcliffe, J. G.; Czabaj, M.

    2016-01-01

    Reported mechanical properties of carbon nanotubes (CNTs) at the nanoscale suggest their potential to enable significantly lighter structures of interest for space applications. However, their utility depends on the retention of these properties in bulk material formats that permit practical fabrication of large structures. This presentation summarizes recent progress made to produce carbon nanotube composites with specific tensile properties that begin to rival those of carbon fiber reinforced polymer composites. CNT content in these nanocomposites was greater than 70% by weight. Tested nanocomposite specimens were fabricated from kilometers or tens of square meters of CNT, depending on the starting material format. Processing methods to yield these results, and characterization and testing to evaluate the performance of these composites will be discussed. The final objective is the demonstration of a CNT composite overwrapped pressure vessel to be flight tested in the Fall of 2016.

  14. Highly reversible lead-carbon battery anode with lead grafting on the carbon surface

    KAUST Repository

    Yin, Jian; Lin, Nan; Zhang, Wenli; Lin, Zheqi; Zhang, Ziqing; Wang, Yue; Shi, Jun; Bao, Jinpeng; Lin, Haibo

    2018-01-01

    A novel C/Pb composite has been successfully prepared by electroless plating to reduce the hydrogen evolution and achieve the high reversibility of the anode of lead-carbon battery (LCB). The deposited lead on the surface of C/Pb composite was found to be uniform and adherent to carbon surface. Because lead has been stuck on the surface of C/Pb composite, the embedded structure suppresses the hydrogen evolution of lead-carbon anode and strengthens the connection between carbon additive and sponge lead. Compared with the blank anode, the lead-carbon anode with C/Pb composite displays excellent charge–discharge reversibility, which is attributed to the good connection between carbon additives and lead that has been stuck on the surface of C/Pb composite during the preparation process. The addition of C/Pb composite maintains a solid anode structure with high specific surface area and power volume, and thereby, it plays a significant role in the highly reversible lead-carbon anode.

  15. Highly reversible lead-carbon battery anode with lead grafting on the carbon surface

    KAUST Repository

    Yin, Jian

    2018-03-27

    A novel C/Pb composite has been successfully prepared by electroless plating to reduce the hydrogen evolution and achieve the high reversibility of the anode of lead-carbon battery (LCB). The deposited lead on the surface of C/Pb composite was found to be uniform and adherent to carbon surface. Because lead has been stuck on the surface of C/Pb composite, the embedded structure suppresses the hydrogen evolution of lead-carbon anode and strengthens the connection between carbon additive and sponge lead. Compared with the blank anode, the lead-carbon anode with C/Pb composite displays excellent charge–discharge reversibility, which is attributed to the good connection between carbon additives and lead that has been stuck on the surface of C/Pb composite during the preparation process. The addition of C/Pb composite maintains a solid anode structure with high specific surface area and power volume, and thereby, it plays a significant role in the highly reversible lead-carbon anode.

  16. Evaluation of the characteristics of high burnup and high plutonium content mixed oxide (MOX) fuel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-08-15

    Two kinds of MOX fuel irradiation tests, i.e., MOX irradiation test up to high burnup and MOX having high plutonium content irradiation test, have been performed from JFY 2007 for five years in order to establish technical data concerning MOX fuel behavior during irradiation, which shall be needed in safety regulation of MOX fuel with high reliability. The high burnup MOX irradiation test consists of irradiation extension and post irradiation examination (PIE). The activities done in JFY 2011 are destructive post irradiation examination (D-PIE) such as EPMA and SIMS at CEA (Commissariat a l'Enegie Atomique) facility. Cadarache and PIE data analysis. In the frame of irradiation test of high plutonium content MOX fuel programme, MOX fuel rods with about 14wt % Pu content are being irradiated at BR-2 reactor and corresponding PIE is also being done at PIE facility (SCK/CEN: Studiecentrum voor Kernenergie/Centre d'Etude l'Energie Nucleaire) in Belgium. The activities done in JFY 2011 are non-destructive post irradiation examination (ND-PIE) and D-PIE and PIE data analysis. In this report the results of EPMA and SIMS with high burnup irradiation test and the result of gamma spectrometry measurement which can give FP gas release rate are reported. (author)

  17. Cultivating Fluorescent Flowers with Highly Luminescent Carbon Dots Fabricated by a Double Passivation Method.

    Science.gov (United States)

    Han, Shuai; Chang, Tao; Zhao, Haiping; Du, Huanhuan; Liu, Shan; Wu, Baoshuang; Qin, Shenjun

    2017-07-07

    In this work, we present the fabrication of highly luminescent carbon dots (CDs) by a double passivation method with the assistance of Ca(OH)₂. In the reaction process, Ca 2+ protects the active functional groups from overconsumption during dehydration and carbonization, and the electron-withdrawing groups on the CD surface are converted to electron-donating groups by the hydroxyl ions. As a result, the fluorescence quantum yield of the CDs was found to increase with increasing Ca(OH)₂ content in the reaction process. A blue-shift optical spectrum of the CDs was also found with increasing Ca(OH)₂ content, which could be attributed to the increasing of the energy gaps for the CDs. The highly photoluminescent CDs obtained (quantum yield: 86%) were used to cultivate fluorescent carnations by a water culture method, while the results of fluorescence microscopy analysis indicated that the CDs had entered the plant tissue structure.

  18. Corrosion resistance testing of high-boron-content stainless steels

    International Nuclear Information System (INIS)

    Petrman, I.; Safek, V.

    1994-01-01

    Boron steels, i.e. stainless steels with boron contents of 0.2 to 2.25 wt.%, are employed in nuclear engineering for the manufacture of baskets or wells in which radioactive fissile materials are stored, mostly spent nuclear fuel elements. The resistance of such steels to intergranular corrosion and uniform corrosion was examined in the Strauss solution and in boric acid; the dependence of the corrosion rate of the steels on their chemical composition was investigated, and their resistance was compared with that of AISI 304 type steel. Corrosion resistance tests in actual conditions of ''wet'' compact storage (demineralized water or a weak boric acid solution) gave evidence that boron steels undergo nearly no uniform corrosion and, as electrochemical measurements indicated, match standard corrosion-resistant steels. Corrosion resistance was confirmed to decrease slightly with increasing boron content and to increase somewhat with increasing molybdenum content. (Z.S.). 3 tabs., 4 figs., 7 refs

  19. Highly Enhanced Raman Scattering on Carbonized Polymer Films.

    Science.gov (United States)

    Yoon, Jong-Chul; Hwang, Jongha; Thiyagarajan, Pradheep; Ruoff, Rodney S; Jang, Ji-Hyun

    2017-06-28

    We have discovered a carbonized polymer film to be a reliable and durable carbon-based substrate for carbon enhanced Raman scattering (CERS). Commercially available SU8 was spin coated and carbonized (c-SU8) to yield a film optimized to have a favorable Fermi level position for efficient charge transfer, which results in a significant Raman scattering enhancement under mild measurement conditions. A highly sensitive CERS (detection limit of 10 -8 M) that was uniform over a large area was achieved on a patterned c-SU8 film and the Raman signal intensity has remained constant for 2 years. This approach works not only for the CMOS-compatible c-SU8 film but for any carbonized film with the correct composition and Fermi level, as demonstrated with carbonized-PVA (poly(vinyl alcohol)) and carbonized-PVP (polyvinylpyrollidone) films. Our study certainly expands the rather narrow range of Raman-active material platforms to include robust carbon-based films readily obtained from polymer precursors. As it uses broadly applicable and cheap polymers, it could offer great advantages in the development of practical devices for chemical/bio analysis and sensors.

  20. High power and high energy electrodes using carbon nanotubes

    Science.gov (United States)

    Martini, Fabrizio; Brambilla, Nicolo Michele; Signorelli, Riccardo

    2015-04-07

    An electrode useful in an energy storage system, such as a capacitor, includes an electrode that includes at least one to a plurality of layers of compressed carbon nanotube aggregate. Methods of fabrication are provided. The resulting electrode exhibits superior electrical performance in terms of gravimetric and volumetric power density.

  1. Hydrogen production from high moisture content biomass in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Antal, M.J. Jr.; Xu, X. [Univ. of Hawaii, Honolulu, HI (United States). Hawaii Natural Energy Inst.

    1998-08-01

    By mixing wood sawdust with a corn starch gel, a viscous paste can be produced that is easily delivered to a supercritical flow reactor by means of a cement pump. Mixtures of about 10 wt% wood sawdust with 3.65 wt% starch are employed in this work, which the authors estimate to cost about $0.043 per lb. Significant reductions in feed cost can be achieved by increasing the wood sawdust loading, but such an increase may require a more complex pump. When this feed is rapidly heated in a tubular flow reactor at pressures above the critical pressure of water (22 MPa), the sawdust paste vaporizes without the formation of char. A packed bed of carbon catalyst in the reactor operating at about 650 C causes the tarry vapors to react with water, producing hydrogen, carbon dioxide, and some methane with a trace of carbon monoxide. The temperature and history of the reactor`s wall influence the hydrogen-methane product equilibrium by catalyzing the methane steam reforming reaction. The water effluent from the reactor is clean. Other biomass feedstocks, such as the waste product of biodiesel production, behave similarly. Unfortunately, sewage sludge does not evidence favorable gasification characteristics and is not a promising feedstock for supercritical water gasification.

  2. Hierarchically structured nanoporous carbon tubes for high pressure carbon dioxide adsorption

    Directory of Open Access Journals (Sweden)

    Julia Patzsch

    2017-05-01

    Full Text Available Mesoscopic, nanoporous carbon tubes were synthesized by a combination of the Stoeber process and the use of electrospun macrosized polystyrene fibres as structure directing templates. The obtained carbon tubes have a macroporous nature characterized by a thick wall structure and a high specific surface area of approximately 500 m²/g resulting from their micro- and mesopores. The micropore regime of the carbon tubes is composed of turbostratic graphitic areas observed in the microstructure. The employed templating process was also used for the synthesis of silicon carbide tubes. The characterization of all porous materials was performed by nitrogen adsorption at 77 K, Raman spectroscopy, infrared spectroscopy, thermal gravimetric analysis (TGA, scanning electron microscopy (SEM as well as transmission electron microscopy (TEM. The adsorption of carbon dioxide on the carbon tubes at 25 °C at pressures of up to 30 bar was studied using a volumetric method. At 26 bar, an adsorption capacity of 4.9 mmol/g was observed. This is comparable to the adsorption capacity of molecular sieves and vertically aligned carbon nanotubes. The high pressure adsorption process of CO2 was found to irreversibly change the microporous structure of the carbon tubes.

  3. The Content of Literature in the High School.

    Science.gov (United States)

    Burton, Dwight L.

    The content of a literature program defined in terms of the structure of literature is proposed. A three-layer definition of structure is suggested which considers (1) the substance of literature, including man and his gods, man and the natural world, man and other men, and man and himself; (2) mode in literature, including the romantic, comic,…

  4. Pedagogical Content Knowledge and Preparation of High School Physics Teachers

    Science.gov (United States)

    Etkina, Eugenia

    2010-01-01

    This paper contains a scholarly description of pedagogical practices of the Rutgers Physics/Physical Science Teacher Preparation program. The program focuses on three aspects of teacher preparation: knowledge of physics, knowledge of pedagogy, and knowledge of how to teach physics (pedagogical content knowledge--PCK). The program has been in place…

  5. Nitrogen-fixing cyanobacterium with a high phycoerythrin content.

    Science.gov (United States)

    Rodriguez, H; Rivas, J; Guerrero, M G; Losada, M

    1989-03-01

    The elemental and molecular composition, pigment content, and productivity of a phycoerythrin-rich nitrogen-fixing cyanobacterium-an Anabaena strain isolated from the coastal lagoon Albufera de Valencia, Spain-has been investigated. When compared with other heterocystous species, this strain exhibits similar chlorophyll a, carotene, and total phycobiliprotein contents but differs remarkably in the relative proportion of specific phycobiliproteins; the content of C-phycoerythrin amounts to 8.3% (versus about 1% in the other species) of cell dry weight. Absorption and fluorescence spectra of intact phycobilisomes isolated from this Anabaena sp. corroborate the marked contribution of phycoerythrin as an antenna pigment, a circumstance that is unusual for cyanobacteria capable of fixing N(2). The pigment content of cells is affected by variations in irradiance and cell density, these adaptive changes being more patent for C-phycoerythrin than for phycocyanins. The Anabaena strain is clumpy and capable of rapid flocculation. It exhibits outdoor productivities higher than 20 g (dry weight) m day during summer.

  6. Highly Crumpled All-Carbon Transistors for Brain Activity Recording.

    Science.gov (United States)

    Yang, Long; Zhao, Yan; Xu, Wenjing; Shi, Enzheng; Wei, Wenjing; Li, Xinming; Cao, Anyuan; Cao, Yanping; Fang, Ying

    2017-01-11

    Neural probes based on graphene field-effect transistors have been demonstrated. Yet, the minimum detectable signal of graphene transistor-based probes is inversely proportional to the square root of the active graphene area. This fundamentally limits the scaling of graphene transistor-based neural probes for improved spatial resolution in brain activity recording. Here, we address this challenge using highly crumpled all-carbon transistors formed by compressing down to 16% of its initial area. All-carbon transistors, chemically synthesized by seamless integration of graphene channels and hybrid graphene/carbon nanotube electrodes, maintained structural integrity and stable electronic properties under large mechanical deformation, whereas stress-induced cracking and junction failure occurred in conventional graphene/metal transistors. Flexible, highly crumpled all-carbon transistors were further verified for in vivo recording of brain activity in rats. These results highlight the importance of advanced material and device design concepts to make improvements in neuroelectronics.

  7. Hybrid carbon nanostructure assemblage for high performance pseudo-capacitors

    Directory of Open Access Journals (Sweden)

    A. K. Mishra

    2012-06-01

    Full Text Available Investigation of novel nanocomposites for pseudo-capacitors with high capacitance and energy density is the spotlight of current energy research. In the present work, hybrid carbon nanostructure assemblage of graphene and multiwalled carbon nanotubes has been used as carbon support to nanostructured RuO2 and polyaniline for high energy supercapacitors. Maximum specific capacitances of 110, 235 and 440 F g−1 at the voltage sweep rate of 10 mV s−1 and maximum energy densities of 7, 12.5 and 20.5 Wh kg−1 were observed for carbon assemblage and its RuO2 and polyanilne decorated nanocomposites, respectively, with 1M H2SO4 as electrolyte.

  8. Thermodynamically Controlled High-Pressure High-Temperature Synthesis of Crystalline Fluorinated sp 3 -Carbon Networks

    Energy Technology Data Exchange (ETDEWEB)

    Klier, Kamil; Landskron, Kai

    2015-11-19

    We report the feasibility of the thermodynamically controlled synthesis of crystalline sp3-carbon networks. We show that there is a critical pressure below which decomposition of the carbon network is favored and above which the carbon network is stable. Based on advanced, highly accurate quantum mechanical calculations using the all-electron full-potential linearized augmented plane-wave method (FP-LAPW) and the Birch–Murnaghan equation of state, this critical pressure is 26.5 GPa (viz. table of contents graphic). Such pressures are experimentally readily accessible and afford thermodynamic control for suppression of decomposition reactions. The present results further suggest that a general pattern of pressure-directed control exists for many isolobal conversions of sp2 to sp3 allotropes, relating not only to fluorocarbon chemistry but also extending to inorganic and solid-state materials science.

  9. High purity neodymium acetate from mixed rare earth carbonates

    International Nuclear Information System (INIS)

    Queiroz, Carlos A. da Silva; Rocha, Soraya M. Rizzo da; Vasconcellos, Mari E. de; Lobo, Raquel M.; Seneda, Jose A.; Pedreira, Walter dos R.

    2011-01-01

    A simple and economical chemical process for obtaining high purity neodymium acetate is discussed. The raw material in the form rare earth carbonate is produced industrially from the chemical treatment of Brazilian monazite. Ion exchange chromatography technique with a strong cationic resin, proper to water treatment, and without the use of retention ions was used for the fractionating of the rare earth elements (REE). In this way, it was possible to obtain 99.9% pure Nd 2 O 3 in yields greater than or equal 80%, with the elution of the REE using ammonium salt of ethylenediaminetetraacetic acid (EDTA) solution in pH controlled. The complex of EDTA-neodymium was transformed into neodymium oxide, which was subsequently dissolved in acetic acid to obtain the neodymium acetates. Molecular absorption spectrophotometry was used to monitor the neodymium content during the process and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the neodymium acetates. The typical neodymium acetates obtained contain the followings contaminants in μg g -1 : Sc(5.1); Y (0.9); La (1.0); Ce (6.1); Pr (34,4); Sm (12.8); Eu (1.1); Gd (15.4); Tb (29.3); Dy (5.2), Ho(7.4); Er (14.6); Tm (0.3); Yb (2.5); Lu (1.0). The high purity neodymium acetates obtained from this procedure have been applied, replacing the imported product, in research and development area on rare earth catalysts. (author)

  10. Effect of Carbon Content on the Properties of Iron-Based Powder Metallurgical Parts Produced by the Surface Rolling Process

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    2018-01-01

    Full Text Available In recent years, the rolling densification process has become increasingly widely used to strengthen powder metallurgy parts. The original composition of the rolled powder metallurgy blank has a significant effect on the rolling densification technology. The present work investigated the effects of different carbon contents (0 wt. %, 0.2 wt. %, 0.45 wt. %, and 0.8 wt. % on the rolling densification. The selection of the raw materials in the surface rolling densification process was analyzed based on the pore condition, structure, hardness, and friction performance of the materials. The results show that the 0.8 wt. % carbon content of the surface rolling material can effectively improve the properties of iron-based powder metallurgy parts. The samples with 0.8 wt. % carbon have the highest surface hardness (340 HV0.1 and the lowest surface friction coefficient (0.35. Even if the dense layer depth is 1.13 mm, which is thinner than other samples with low carbon content, it also meets the requirements for powder metallurgy parts such as gears used in the auto industry.

  11. High water content in primitive continental flood basalts.

    Science.gov (United States)

    Xia, Qun-Ke; Bi, Yao; Li, Pei; Tian, Wei; Wei, Xun; Chen, Han-Lin

    2016-05-04

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>10(5) km(3)) within short time span (primitive CFB in the early Permian Tarim large igneous province (NW China), using the H2O content of ten early-formed clinopyroxene (cpx) crystals that recorded the composition of the primitive Tarim basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB.

  12. Pedagogical content knowledge and preparation of high school physics teachers

    OpenAIRE

    Eugenia Etkina

    2010-01-01

    This paper contains a scholarly description of pedagogical practices of the Rutgers Physics/Physical Science Teacher Preparation program. The program focuses on three aspects of teacher preparation: knowledge of physics, knowledge of pedagogy, and knowledge of how to teach physics (pedagogical content knowledge—PCK). The program has been in place for 7 years and has a steady production rate of an average of six teachers per year who remain in the profession. The main purpose of the paper is t...

  13. Heavily Graphitic-Nitrogen Self-doped High-porosity Carbon for the Electrocatalysis of Oxygen Reduction Reaction

    Science.gov (United States)

    Feng, Tong; Liao, Wenli; Li, Zhongbin; Sun, Lingtao; Shi, Dongping; Guo, Chaozhong; Huang, Yu; Wang, Yi; Cheng, Jing; Li, Yanrong; Diao, Qizhi

    2017-11-01

    Large-scale production of active and stable porous carbon catalysts for oxygen reduction reaction (ORR) from protein-rich biomass became a hot topic in fuel cell technology. Here, we report a facile strategy for synthesis of nitrogen-doped porous nanocarbons by means of a simple two-step pyrolysis process combined with the activation of zinc chloride and acid-treatment process, in which kidney bean via low-temperature carbonization was preferentially adopted as the only carbon-nitrogen sources. The results show that this carbon material exhibits excellent ORR electrocatalytic activity, and higher durability and methanol-tolerant property compared to the state-of-the-art Pt/C catalyst for the ORR, which can be mainly attributed to high graphitic-nitrogen content, high specific surface area, and porous characteristics. Our results can encourage the synthesis of high-performance carbon-based ORR electrocatalysts derived from widely-existed natural biomass.

  14. Dependence of microhardness of coke on carbon content and final coking temperature

    Energy Technology Data Exchange (ETDEWEB)

    Kaloc, M.; Dvorak, P.

    1995-12-31

    At present time is important the coke-quality, tested by various methods again. The new methods of evaluation of coke quality as e.g. CSR, CRI, ACRI etc. demonstrate, that the mechanical stability parameters are in connection of microstructure of coke mass. The purpose of present paper is to investigate the dependence of microhardness on the carbon content and the final carbonisation temperature in the coal-coke series. The samples prepared experimentally in more series from different coal blends from 20{degrees}C to 1100{degrees}C were investigated both mega- and microscopically. The tests of microhardness are based on the use of the Hanemann microhardness tester. Principally this method consists in impressing the diamond pyramid into the surface of the sample. The data on the pressure applied are subtracted on the scale of load. An important factor influencing the results is the choice of the points from which the sample is to be withdrawn. The choice is dependent on the aim to be achieved. For the determination of an average microhardness it is sufficient to take sample from the middle part of the coke block representing the half width of the coking chamber. The choice of the point is also of great importance. In strong and homogeneous walls, sharply bounded, impressions can be found with a distinct diagonal cross. In thin walls the impressions are distinguished by distinct boundaries, the middle part, however, not being distinct as the pyramidal point did not penetrate the wall. Impressions providing accurate values are those distinctly bounded by a distinct diagonal cross. The walls not having been chosen correctly, the errors reveal themselves as the scattering of the points in the diagrams of microhardness.

  15. One-pot synthetic method to prepare highly N-doped nanoporous carbons for CO2 adsorption

    International Nuclear Information System (INIS)

    Meng, Long-Yue; Park, Soo-Jin

    2014-01-01

    A one-pot synthetic method was used for the preparation of nanoporous carbon containing nitrogen from polypyrrole (PPY) using NaOH as the activated agent. The activation process was carried out under set conditions (NaOH/PPY = 2 and NaOH/PPY = 4) at different temperatures in 600–900 °C for 2 h. The effect of the activation conditions on the pore structure, surface functional groups and CO 2 adsorption capacities of the prepared N-doped activated carbons was examined. The carbon was analyzed by X-ray photoelectron spectroscopy (XPS), N2/77 K full isotherms, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The CO 2 adsorption capacity of the N-doped activated carbon was measured at 298 K and 1 bar. By dissolving the activation agents, the N-doped activated carbon exhibited high specific surface areas (755–2169 m 2 g −1 ) and high pore volumes (0.394–1.591 cm 3 g −1 ). In addition, the N-doped activated carbons contained a high N content at lower activation temperatures (7.05 wt.%). The N-doped activated carbons showed a very high CO 2 adsorption capacity of 177 mg g −1 at 298 K and 1 bar. The CO 2 adsorption capacity was found to be dependent on the microporosity and N contents. - Highlights: • A one-pot synthetic method was used for the preparation of N-doped nanoporous carbons. • Polypyrrole (PPY) were activated with NaOH under set conditions (NaOH/PPY = 2 and 4). • N-doped activated carbon exhibited high specific surface areas (2169 m 2 g −1 ). • The carbons showed a very high CO 2 adsorption capacity of 177 mg g −1 at 298 K

  16. Decomposition kinetics of expanded austenite with high nitrogen contents

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2006-01-01

    This paper addresses the decomposition kinetics of synthesized homogeneous expanded austenite formed by gaseous nitriding of stainless steel AISI 304L and AISI 316L with nitrogen contents up to 38 at.% nitrogen. Isochronal annealing experiments were carried out in both inert (N2) and reducing (H2......) atmospheres. Differential thermal analysis (DTA) and thermogravimetry were applied for identification of the decomposition reactions and X-ray diffraction analysis was applied for phase analysis. CrN precipitated upon annealing; the activation energies are 187 kJ/mol and 128 kJ/mol for AISI 316L and AISI 304L...

  17. Uranium extraction from high content chlorine leach liquor

    International Nuclear Information System (INIS)

    Fatemi, K.

    1998-01-01

    In this work uranium solution has been leached out by leaching process of uranium ores from Bandar-Ab bass port using sea water, since fresh water could not be available when it is processed in large scale. Two samples of different batches containing 11 and 20 gr./lit chlorine underwent two stages of precipitation by lead nitrate. As the result of this treatment the chlorine removed and its final concentration reduced to 530 p.p.m. which is well below allowances. Then, the uranium of this recent dechlorinated solu ton has been extracted by T.B.P. Uranium in organic phase was stripped out into inorganic phase by sodium carbonate and precipitated in a form of yellow cake and converted to U3o8. The total recovery of U, was well above 90% and the purity of the conc. U was better than 94%. The lead used at the beginning of the process was recovered for next use

  18. Confinement of hydrogen at high pressure in carbon nanotubes

    Science.gov (United States)

    Lassila, David H [Aptos, CA; Bonner, Brian P [Livermore, CA

    2011-12-13

    A high pressure hydrogen confinement apparatus according to one embodiment includes carbon nanotubes capped at one or both ends thereof with a hydrogen-permeable membrane to enable the high pressure confinement of hydrogen and release of the hydrogen therethrough. A hydrogen confinement apparatus according to another embodiment includes an array of multi-walled carbon nanotubes each having first and second ends, the second ends being capped with palladium (Pd) to enable the high pressure confinement of hydrogen and release of the hydrogen therethrough as a function of palladium temperature, wherein the array of carbon nanotubes is capable of storing hydrogen gas at a pressure of at least 1 GPa for greater than 24 hours. Additional apparatuses and methods are also presented.

  19. Increase of porosity by combining semi-carbonization and KOH activation of formaldehyde resins to prepare high surface area carbons for supercapacitor applications

    Science.gov (United States)

    Heimböckel, Ruben; Kraas, Sebastian; Hoffmann, Frank; Fröba, Michael

    2018-01-01

    A series of porous carbon samples were prepared by combining a semi-carbonization process of acidic polymerized phenol-formaldehyde resins and a following chemical activation with KOH used in different ratios to increase specific surface area, micropore content and pore sizes of the carbons which is favourable for supercapacitor applications. Samples were characterized by nitrogen physisorption, powder X-ray diffraction, Raman spectroscopy and scanning electron microscopy. The results show that the amount of KOH, combined with the semi-carbonization step had a remarkable effect on the specific surface area (up to SBET: 3595 m2 g-1 and SDFT: 2551 m2 g-1), pore volume (0.60-2.62 cm3 g-1) and pore sizes (up to 3.5 nm). The carbons were tested as electrode materials for electrochemical double layer capacitors (EDLC) in a two electrode setup with tetraethylammonium tetrafluoroborate in acetonitrile as electrolyte. The prepared carbon material with the largest surface area, pore volume and pore sizes exhibits a high specific capacitance of 145.1 F g-1 at a current density of 1 A g-1. With a high specific energy of 31 W h kg-1 at a power density of 33028 W kg-1 and a short time relaxation constant of 0.29 s, the carbon showed high power capability as an EDLC electrode material.

  20. General corrosion of carbon steels in high temperature water

    International Nuclear Information System (INIS)

    Gras, J.M.

    1994-04-01

    This short paper seeks to provide a summary of the main knowledge about the general corrosion of carbon steels in high temperature water. In pure water or slightly alkaline deaerated water, steels develop a protective coating of magnetite in a double layer (Potter and Mann oxide) or a single layer (Bloom oxide). The morphology of the oxide layer and the kinetics of corrosion depend on the test parameters controlling the solubility of iron. The parameters exercising the greatest influence are partial hydrogen pressure and mass transfer: hydrogen favours the solubilization of the magnetite; the entrainment of the dissolved iron prevents a redeposition of magnetite on the surface of the steel. Cubic or parabolic in static conditions, the kinetics of corrosion tends to be linear in dynamic conditions. In dynamic operation, corrosion is at least one order of magnitude lower in water with a pH of 10 than in pure water with a pH of 7. The activation energy of corrosion is 130 kJ/mol (31 kcal/mol). This results in the doubling of corrosion at around 300 deg C for a temperature increase of 15 deg C. Present in small quantities (100-200 ppb), oxygen decreases general corrosion but increases the risk of pitting corrosion - even for a low chloride content - and stress corrosion cracking or corrosion-fatigue. The steel composition has probably an influence on the kinetics of corrosion in dynamic conditions; further work would be required to clarify the effect of some residual elements. (author). 31 refs., 9 figs., 2 tabs

  1. Synthesis of partially graphitic ordered mesoporous carbons with high surface areas

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Wenjun; Wan, Ying [Department of Chemistry, Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Normal University, Shanghai 200234 (China); Dou, Yuqian; Zhao, Dongyuan [Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433 (China)

    2011-01-01

    Graphitic carbons with ordered mesostructure and high surface areas (of great interest in applications such as energy storage) have been synthesized by a direct triblock-copolymer-templating method. Pluronic F127 is used as a structure-directing agent, with a low-molecular-weight phenolic resol as a carbon source, ferric oxide as a catalyst, and silica as an additive. Inorganic oxides can be completely eliminated from the carbon. Small-angle XRD and N{sub 2} sorption analysis show that the resultant carbon materials possess an ordered 2D hexagonal mesostructure, uniform bimodal mesopores (about 1.5 and 6 nm), high surface area ({proportional_to}1300 m{sup 2}/g), and large pore volumes ({proportional_to}1.50 cm{sup 3}/g) after low-temperature pyrolysis (900 C). All surface areas come from mesopores. Wide-angle XRD patterns demonstrate that the presence of the ferric oxide catalyst and the silica additive lead to a marked enhancement of graphitic ordering in the framework. Raman spectra provide evidence of the increased content of graphitic sp{sup 2} carbon structures. Transmission electron microscopy images confirm that numerous domains in the ordered mesostructures are composed of characteristic graphitic carbon nanostructures. The evolution of the graphitic structure is dependent on the temperature and the concentrations of the silica additive, and ferric oxide catalyst. Electrochemical measurements performed on this graphitic mesoporous carbon when used as an electrode material for an electrochemical double layer capacitor shows rectangular-shaped cyclic voltammetry curves over a wide range of scan rates, even up to 200 mV/s, with a large capacitance of 155 F/g in KOH electrolyte. This method can be widely applied to the synthesis of graphitized carbon nanostructures. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. A Simple Beta-Function Model for Soil-Water Repellency as a Function of Water and Organic Carbon Contents

    DEFF Research Database (Denmark)

    Karunarathna, Anurudda Kumara; Kawamoto, Ken; Møldrup, Per

    2010-01-01

    Soil-water content (θ) and soil organic carbon (SOC) are key factors controlling the occurrence and magnitude of soil-water repellency (WR). Although expressions have recently been proposed to describe the nonlinear variation of WR with θ, the inclusion of easily measurable parameters in predictive...... conditions for 19 soils were used to test the model. The beta function successfully reproduced all the measured soil-water repellency characteristic, α(θ), curves. Significant correlations were found between model parameters and SOC content (1%-14%). The model was independently tested against data...

  3. Modelling Soil Carbon Content in South Patagonia and Evaluating Changes According to Climate, Vegetation, Desertification and Grazing

    Directory of Open Access Journals (Sweden)

    Pablo Luis Peri

    2018-02-01

    Full Text Available In Southern Patagonia, a long-term monitoring network has been established to assess bio-indicators as an early warning of environmental changes due to climate change and human activities. Soil organic carbon (SOC content in rangelands provides a range of important ecosystem services and supports the capacity of the land to sustain plant and animal productivity. The objectives in this study were to model SOC (30 cm stocks at a regional scale using climatic, topographic and vegetation variables, and to establish a baseline that can be used as an indicator of rangeland condition. For modelling, we used a stepwise multiple regression to identify variables that explain SOC variation at the landscape scale. With the SOC model, we obtained a SOC map for the entire Santa Cruz province, where the variables derived from the multiple linear regression models were integrated into a geographic information system (GIS. SOC stock to 30 cm ranged from 1.38 to 32.63 kg C m−2. The fitted model explained 76.4% of SOC variation using as independent variables isothermality, precipitation seasonality and vegetation cover expressed as a normalized difference vegetation index. The SOC map discriminated in three categories (low, medium, high determined patterns among environmental and land use variables. For example, SOC decreased with desertification due to erosion processes. The understanding and mapping of SOC in Patagonia contributes as a bridge across main issues such as climate change, desertification and biodiversity conservation.

  4. Geophysical Prediction Technology Based on Organic Carbon Content in Source Rocks of the Huizhou Sag, the South China Sea

    Directory of Open Access Journals (Sweden)

    Yang Wei

    2017-08-01

    Full Text Available Due to the high exploration cost, limited number of wells for source rocks drilling and scarce test samples for the Total Organic Carbon Content (TOC in the Huizhou sag, the TOC prediction of source rocks in this area and the assessment of resource potentials of the basin are faced with great challenges. In the study of TOC prediction, predecessors usually adopted the logging assessment method, since the data is only confined to a “point” and the regional prediction of the source bed in the seismic profile largely depends on the recognition of seismic facies, making it difficult to quantify TOC. In this study, we combined source rock geological characteristics, logging and seismic response and built the mathematical relation between quasi TOC curve and seismic data based on the TOC logging date of a single well and its internal seismic attribute. The result suggested that it was not purely a linear relationship that was adhered to by predecessors, but was shown as a complicated non-linear relationship. Therefore, the neural network algorithm and SVMs were introduced to obtain the optimum relationship between the quasi TOC curve and the seismic attribute. Then the goal of TOC prediction can be realized with the method of seismic inversion.

  5. Optimization of solid content, carbon/nitrogen ratio and food/inoculum ratio for biogas production from food waste.

    Science.gov (United States)

    Dadaser-Celik, Filiz; Azgin, Sukru Taner; Yildiz, Yalcin Sevki

    2016-12-01

    Biogas production from food waste has been used as an efficient waste treatment option for years. The methane yields from decomposition of waste are, however, highly variable under different operating conditions. In this study, a statistical experimental design method (Taguchi OA 9 ) was implemented to investigate the effects of simultaneous variations of three parameters on methane production. The parameters investigated were solid content (SC), carbon/nitrogen ratio (C/N) and food/inoculum ratio (F/I). Two sets of experiments were conducted with nine anaerobic reactors operating under different conditions. Optimum conditions were determined using statistical analysis, such as analysis of variance (ANOVA). A confirmation experiment was carried out at optimum conditions to investigate the validity of the results. Statistical analysis showed that SC was the most important parameter for methane production with a 45% contribution, followed by F/I ratio with a 35% contribution. The optimum methane yield of 151 l kg -1 volatile solids (VS) was achieved after 24 days of digestion when SC was 4%, C/N was 28 and F/I were 0.3. The confirmation experiment provided a methane yield of 167 l kg -1 VS after 24 days. The analysis showed biogas production from food waste may be increased by optimization of operating conditions. © The Author(s) 2016.

  6. Determination of oxygen content and carbonate impurity in YBa2Cu3O7-x by diffuse reflectance infrared spectroscopy

    International Nuclear Information System (INIS)

    Merzbacher, C.I.; Bonner, B.P.

    1991-01-01

    Samples of YBa 2 Cu 3 O 7-x with x ranging from ∼0 to 0.65 have been analyzed by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) in the midinfrared region (400--6000 cm -1 ). Spectral line shapes vary gradually as a function of oxygen stoichiometry, and the reflectance at 400 and 1000 cm -1 decreases linearly with decreasing oxygen content. Spectra of samples that were incompletely synthesized or exposed to a 4% CO 2 atmosphere at 650 degree C clearly indicated the presence of carbonate. DRIFTS is therefore a quick, nondestructive method for determining oxygen content in YBa 2 Cu 3 O 7-x powders, and for detecting carbonate species due to synthesis error or reaction with CO 2 -bearing atmosphere

  7. Calcium carbonate as a possible dosimeter for high irradiation doses

    International Nuclear Information System (INIS)

    Negron M, A.; Ramos B, S.; Camargo R, C.; Uribe, R. M.; Gomez V, V.; Kobayashi, K.

    2014-08-01

    The aim of this work is to analyze the interactions of 5 MeV electron beam radiation and a 290 MeV/u Carbon beam with calcium carbonate (powder) at 298 K and at different irradiation doses, for the potential use of calcium carbonate as a high-dose dosimeter. The irradiation doses with the electron beam were from 0.015 to 9 MGy, and with Carbon beam from 1.5 kGy to 8 kGy. High-energy radiation induces the formation of free radicals in solid calcium carbonate that can be detected and measured by electron paramagnetic resonance (EPR). An increase of the EPR response for some of the free radicals produced in the sample was observed as a function of the irradiation dose. The response of one of the radicals decreased with the dose. These measurements are reproducible; the preparation of the sample is simple and inexpensive; and the signal is stable for several months. The response curves show that the dosimeter tends to saturate at 10 MGy. Based on these properties, we propose this chemical compound as a high-dose dosimeter, mainly for electron irradiation. (author)

  8. Calcium carbonate as a possible dosimeter for high irradiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Negron M, A.; Ramos B, S.; Camargo R, C. [UNAM, Instituto de Ciencias Nucleares, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Uribe, R. M. [Kent State University, College of Technology, Kent OH (United States); Gomez V, V. [UNAM, Instituto de Quimica, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Kobayashi, K., E-mail: negron@nucleares.unam.mx [Yokohama National University (Japan)

    2014-08-15

    The aim of this work is to analyze the interactions of 5 MeV electron beam radiation and a 290 MeV/u Carbon beam with calcium carbonate (powder) at 298 K and at different irradiation doses, for the potential use of calcium carbonate as a high-dose dosimeter. The irradiation doses with the electron beam were from 0.015 to 9 MGy, and with Carbon beam from 1.5 kGy to 8 kGy. High-energy radiation induces the formation of free radicals in solid calcium carbonate that can be detected and measured by electron paramagnetic resonance (EPR). An increase of the EPR response for some of the free radicals produced in the sample was observed as a function of the irradiation dose. The response of one of the radicals decreased with the dose. These measurements are reproducible; the preparation of the sample is simple and inexpensive; and the signal is stable for several months. The response curves show that the dosimeter tends to saturate at 10 MGy. Based on these properties, we propose this chemical compound as a high-dose dosimeter, mainly for electron irradiation. (author)

  9. The carbon dioxide content in ice cores - climatic curves of carbon dioxide. Zu den CO sub 2 -Klimakurven aus Eisbohrkernen

    Energy Technology Data Exchange (ETDEWEB)

    Heyke, H.E.

    1992-05-01

    The 'greenhouse effect', which implies a temperature of 15 deg C as against -18 deg C, owes its effect to 80% from water (clouds and gaseous phase) and to 10% from carbon dioxide, besides other components. Whereas water is largely unaccounted for, carbon dioxide has been postulated as the main cause of anticipated climatic catastrophe. The carbon dioxide concentration in the atmosphere has risen presently to such levels that all previous figures seem to have been left far behind. The reference point is the concentration of carbon dioxide in the air bubbles trapped in ice cores of Antartic and Greenland ice dated 160 000 years ago, which show much lower values than at present. A review of the most relevant publications indicates that many basic laws of chemistry seem to have been left largely unconsidered and experimental errors have made the results rather doubtful. Appropriate arguments have been presented. The investigations considered should be repeated under improved and more careful conditions. (orig.).

  10. Pedagogical content knowledge and preparation of high school physics teachers

    Directory of Open Access Journals (Sweden)

    Eugenia Etkina

    2010-08-01

    Full Text Available This paper contains a scholarly description of pedagogical practices of the Rutgers Physics/Physical Science Teacher Preparation program. The program focuses on three aspects of teacher preparation: knowledge of physics, knowledge of pedagogy, and knowledge of how to teach physics (pedagogical content knowledge—PCK. The program has been in place for 7 years and has a steady production rate of an average of six teachers per year who remain in the profession. The main purpose of the paper is to provide information about a possible structure, organization, and individual elements of a program that prepares physics teachers. The philosophy of the program and the coursework can be implemented either in a physics department or in a school of education. The paper provides details about the program course work and teaching experiences and suggests ways to adapt it to other local conditions.

  11. Automated microscopy for high-content RNAi screening

    Science.gov (United States)

    2010-01-01

    Fluorescence microscopy is one of the most powerful tools to investigate complex cellular processes such as cell division, cell motility, or intracellular trafficking. The availability of RNA interference (RNAi) technology and automated microscopy has opened the possibility to perform cellular imaging in functional genomics and other large-scale applications. Although imaging often dramatically increases the content of a screening assay, it poses new challenges to achieve accurate quantitative annotation and therefore needs to be carefully adjusted to the specific needs of individual screening applications. In this review, we discuss principles of assay design, large-scale RNAi, microscope automation, and computational data analysis. We highlight strategies for imaging-based RNAi screening adapted to different library and assay designs. PMID:20176920

  12. Highly porous activated carbons prepared from carbon rich Mongolian anthracite by direct NaOH activation

    Energy Technology Data Exchange (ETDEWEB)

    Byamba-Ochir, Narandalai [School of Chemical Engineering, Chonnam National University, 77 Yongbong-Ro, Gwangju 61186 (Korea, Republic of); Shim, Wang Geun [Department of Polymer Science and Engineering, Sunchon National University, 255 Jungang-Ro, Suncheon, Jeollanam-Do 57922 (Korea, Republic of); Balathanigaimani, M.S., E-mail: msbala@rgipt.ac.in [Department of Chemical Engineering, Rajiv Gandhi Institute of Petroleum Technology, Ratapur Chowk, Rae Bareli, 229316 Uttar Pradesh (India); Moon, Hee, E-mail: hmoon@jnu.ac.kr [School of Chemical Engineering, Chonnam National University, 77 Yongbong-Ro, Gwangju 61186 (Korea, Republic of)

    2016-08-30

    Highlights: • Highly porous carbon materials from Mongolian anthracite by chemical activation. • Cheaper and eco-friendly activation process has been employed. • Activated carbons with graphitic structure and energetically heterogeneous surface. • Surface hydrophobicity and porosity of the activated carbons can be controlled. - Abstract: Highly porous activated carbons (ACs) were prepared from Mongolian raw anthracite (MRA) using sodium hydroxide as an activation agent by varying the mass ratio (powdered MRA/NaOH) as well as the mixing method of chemical agent and powdered MRA. The specific BET surface area and total pore volume of the prepared MRA-based activated carbons (MACs) are in the range of 816–2063 m{sup 2}/g and of 0.55–1.61 cm{sup 3}/g, respectively. The pore size distribution of MACs show that most of the pores are in the range from large micropores to small mesopores and their distribution can be controlled by the mass ratio and mixing method of the activating agent. As expected from the intrinsic property of the MRA, the highly graphitic surface morphology of prepared carbons was confirmed from Raman spectra and transmission electron microscopy (TEM) studies. Furthermore the FTIR and XPS results reveal that the preparation of MACs with hydrophobic in nature is highly possible by controlling the mixing conditions of activating agent and powdered MRA. Based on all the results, it is suggested that the prepared MACs could be used for many specific applications, requiring high surface area, optimal pore size distribution, proper surface hydrophobicity as well as strong physical strength.

  13. Revision of Fontes & Garnier's model for the initial 14C content of dissolved inorganic carbon used in groundwater dating

    Science.gov (United States)

    Han, Liang-Feng; Plummer, Niel

    2013-01-01

    The widely applied model for groundwater dating using 14C proposed by Fontes and Garnier (F&G) (Fontes and Garnier, 1979) estimates the initial 14C content in waters from carbonate-rock aquifers affected by isotopic exchange. Usually, the model of F&G is applied in one of two ways: (1) using a single 13C fractionation factor of gaseous CO2 with respect to a solid carbonate mineral, εg/s, regardless of whether the carbon isotopic exchange is controlled by soil CO2 in the unsaturated zone, or by solid carbonate mineral in the saturated zone; or (2) using different fractionation factors if the exchange process is dominated by soil CO2 gas as opposed to solid carbonate mineral (typically calcite). An analysis of the F&G model shows an inadequate conceptualization, resulting in underestimation of the initial 14C values (14C0) for groundwater systems that have undergone isotopic exchange. The degree to which the 14C0 is underestimated increases with the extent of isotopic exchange. Examples show that in extreme cases, the error in calculated adjusted initial 14C values can be more than 20% modern carbon (pmc). A model is derived that revises the mass balance method of F&G by using a modified model conceptualization. The derivation yields a “global” model both for carbon isotopic exchange dominated by gaseous CO2 in the unsaturated zone, and for carbon isotopic exchange dominated by solid carbonate mineral in the saturated zone. However, the revised model requires different parameters for exchange dominated by gaseous CO2 as opposed to exchange dominated by solid carbonate minerals. The revised model for exchange dominated by gaseous CO2 is shown to be identical to the model of Mook (Mook, 1976). For groundwater systems where exchange occurs both in the unsaturated zone and saturated zone, the revised model can still be used; however, 14C0 will be slightly underestimated. Finally, in carbonate systems undergoing complex geochemical reactions, such as oxidation of

  14. Effect of the hypo and hyperstoichiometry of niobium about the solidification of steel with medium carbon content

    International Nuclear Information System (INIS)

    Kestenbach, H.-J.; Rodrigues, J.A.; Makray, E.T.

    1984-01-01

    The solidification sequency and the microstructure from carbon steel with 0.4%C and several content of Nb were investigated. Additions between 1 and 5% in Nb weight to obtain compositions hypo and hyperstoichiometric in relation to the niobium carbide formation were used. The metallographic observations were interpreted based in several solidifications reactions that could be occur in the iron rich region of the ternary diagram Fe-Nb-C. (E.G.) [pt

  15. Effects of retained austenite volume fraction, morphology, and carbon content on strength and ductility of nanostructured TRIP-assisted steels

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Y.F., E-mail: shenyf@smm.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, 3 Wenhua Road, Shenyang 110004 (China); Qiu, L.N. [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, 3 Wenhua Road, Shenyang 110004 (China); Sun, X. [Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352 (United States); Zuo, L. [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, 3 Wenhua Road, Shenyang 110004 (China); Liaw, P.K. [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996 (United States); Raabe, D. [Max-Planck-Institut fuer Eisenforschung, Max-Planck-Str. 1, 8, 40237 Düsseldorf (Germany)

    2015-06-11

    With a suite of multi-modal and multi-scale characterization techniques, the present study unambiguously proves that a substantially-improved combination of ultrahigh strength and good ductility can be achieved by tailoring the volume fraction, morphology, and carbon content of the retained austenite (RA) in a transformation-induced-plasticity (TRIP) steel with the nominal chemical composition of 0.19C–0.30Si–1.76Mn–1.52Al (weight percent, wt%). After intercritical annealing and bainitic holding, a combination of ultimate tensile strength (UTS) of 1100 MPa and true strain of 50% has been obtained, as a result of the ultrafine RA lamellae, which are alternately arranged in the bainitic ferrite around junction regions of ferrite grains. For reference, specimens with a blocky RA, prepared without the bainitic holding, yield a low ductility (35%) and a low UTS (800 MPa). The volume fraction, morphology, and carbon content of RA have been characterized using various techniques, including the magnetic probing, scanning electron microscopy (SEM), electron-backscatter-diffraction (EBSD), and transmission electron microscopy (TEM). Interrupted tensile tests, mapped using EBSD in conjunction with the kernel average misorientation (KAM) analysis, reveal that the lamellar RA is the governing microstructure component responsible for the higher mechanical stability, compared to the blocky one. By coupling these various techniques, we quantitatively demonstrate that in addition to the RA volume fraction, its morphology and carbon content are equally important in optimizing the strength and ductility of TRIP-assisted steels.

  16. Synthesis of nitrogen doped microporous carbons prepared by activation-free method and their high electrochemical performance

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki-Seok [Department of Chemistry, Inha University, Incheon 402-751 (Korea, Republic of); Park, Soo-Jin, E-mail: sjpark@inha.ac.kr [Department of Chemistry, Inha University, Incheon 402-751 (Korea, Republic of)

    2011-11-30

    Graphical abstract: This describes the increase of specific capacitance in hybrid electrodes as a function of melamine content. Display Omitted Highlights: > For N-enriched hybrid carbons, co-precursors, PVDF/melamine composites, were used. > Microporous carbons were formed by only carbonization without chemical activation. > The nitrogen content of microporous carbons was controlled by melamine content. > N-doped carbons showed higher specific capacitance compared to microporous carbons. > It was attributed to the easy electron transfer and pseudocapacitance. - Abstract: Nitrogen-doped microporous carbons (N-MCs) were prepared by the carbonization of the polyvinylidene fluoride (PVDF)/melamine mixture without chemical activation. The electrochemical performance of the N-MCs was investigated as a function of PVDF/melamine ratio. It was found that, without additional activation, the N-MCs had a high specific surface area (greater than 560 m{sup 2}/g) because of the micropore formation by the release of fluorine groups. In addition, although the specific surface area decreased, nitrogen groups were increased with increasing melamine content, leading to an enhanced electrochemical performance. Indeed, the N-MCs showed a better electrochemical performance than that of microporous carbons (MCs) prepared by PVDF alone, and the highest specific capacitance (310 F/g) was obtained at a current density of 0.5 A/g, as compared to a value of 248 F/g for MCs. These results indicate that the microporous features of N-MC lead to feasible ion transfer during charge/discharge duration and the presence of nitrogen groups as strong electron donor on the N-MC electrode in electrolyte could provide a pseudocapacitance by the redox reaction.

  17. Synthesis of nitrogen doped microporous carbons prepared by activation-free method and their high electrochemical performance

    International Nuclear Information System (INIS)

    Kim, Ki-Seok; Park, Soo-Jin

    2011-01-01

    Graphical abstract: This describes the increase of specific capacitance in hybrid electrodes as a function of melamine content. Display Omitted Highlights: → For N-enriched hybrid carbons, co-precursors, PVDF/melamine composites, were used. → Microporous carbons were formed by only carbonization without chemical activation. → The nitrogen content of microporous carbons was controlled by melamine content. → N-doped carbons showed higher specific capacitance compared to microporous carbons. → It was attributed to the easy electron transfer and pseudocapacitance. - Abstract: Nitrogen-doped microporous carbons (N-MCs) were prepared by the carbonization of the polyvinylidene fluoride (PVDF)/melamine mixture without chemical activation. The electrochemical performance of the N-MCs was investigated as a function of PVDF/melamine ratio. It was found that, without additional activation, the N-MCs had a high specific surface area (greater than 560 m 2 /g) because of the micropore formation by the release of fluorine groups. In addition, although the specific surface area decreased, nitrogen groups were increased with increasing melamine content, leading to an enhanced electrochemical performance. Indeed, the N-MCs showed a better electrochemical performance than that of microporous carbons (MCs) prepared by PVDF alone, and the highest specific capacitance (310 F/g) was obtained at a current density of 0.5 A/g, as compared to a value of 248 F/g for MCs. These results indicate that the microporous features of N-MC lead to feasible ion transfer during charge/discharge duration and the presence of nitrogen groups as strong electron donor on the N-MC electrode in electrolyte could provide a pseudocapacitance by the redox reaction.

  18. Bainite formation kinetics in high carbon alloyed steel

    International Nuclear Information System (INIS)

    Luzginova, N.V.; Zhao, L.; Sietsma, J.

    2008-01-01

    In recent years, many investigations have been carried out on the modeling of the bainite formation. In the present work, a physical approach proposed in the literature is implemented to model the formation of lower bainite in high carbon steels (1 wt.% C). In this model, the carbon diffusion is assumed to control the kinetics of the bainite formation. Both the nucleation and the growth rates are considered in an Avrami type analysis. The effect of alloying elements is taken into account considering only the thermodynamics of the system. The results and the physical meaning of the model parameters are discussed. It is shown that the diffusional approach gives a reasonable description of bainite formation kinetics in high carbon steel. Only two fitting parameters are used: the first accounts for carbon grain-boundary diffusion and the second is the initial nucleation-site density. The model satisfactorily accounts for the effect of transformation temperature, but does not take into account the carbide precipitation during bainite formation and the effect of alloying elements on the diffusion coefficient of carbon

  19. High toughness in the intercritically reheated coarse-grained (ICRCG) heat-affected zone (HAZ) of low carbon microalloyed steel

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jun, E-mail: hujunral@163.com [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Du, Lin-Xiu [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Wang, Jian-Jun [Institute of Materials Research, School of Material and Metallurgy, Northeastern University, Shenyang 110819 (China); Xie, Hui; Gao, Cai-Ru [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Misra, R.D.K. [Laboratory for Excellence in Advanced Steel Research, Center for Structural and Functional Materials, University of Louisiana at Lafayette, Lafayette, LA 70504-4130 (United States)

    2014-01-10

    Motivated by the small lattice mismatch between ferrite and vanadium nitride (VN), we describe here the welding thermal cycle simulation that provides high toughness in the ICRCG HAZ of low carbon V–N steel. This unique behavior is attributed to the formation of ultra-fine grained ferrite along prior austenite grain boundaries generated by the first pass welding thermal cycle with high misorientation boundaries, where V(C, N) precipitates provide potential nucleation sites for ferrite, leading to extraordinary refinement of martensite/austenite (M/A) constituent. Nitrogen stimulates the precipitation behavior of V(C, N). The nucleation of high density of V(C, N) precipitates consumes carbon-content in the austenite, leading to decrease in the carbon-content in the M/A constituent, with consequent decrease in hardness. The increase in toughness is explained in terms of Griffith's crack propagation theory.

  20. High toughness in the intercritically reheated coarse-grained (ICRCG) heat-affected zone (HAZ) of low carbon microalloyed steel

    International Nuclear Information System (INIS)

    Hu, Jun; Du, Lin-Xiu; Wang, Jian-Jun; Xie, Hui; Gao, Cai-Ru; Misra, R.D.K.

    2014-01-01

    Motivated by the small lattice mismatch between ferrite and vanadium nitride (VN), we describe here the welding thermal cycle simulation that provides high toughness in the ICRCG HAZ of low carbon V–N steel. This unique behavior is attributed to the formation of ultra-fine grained ferrite along prior austenite grain boundaries generated by the first pass welding thermal cycle with high misorientation boundaries, where V(C, N) precipitates provide potential nucleation sites for ferrite, leading to extraordinary refinement of martensite/austenite (M/A) constituent. Nitrogen stimulates the precipitation behavior of V(C, N). The nucleation of high density of V(C, N) precipitates consumes carbon-content in the austenite, leading to decrease in the carbon-content in the M/A constituent, with consequent decrease in hardness. The increase in toughness is explained in terms of Griffith's crack propagation theory

  1. SU-8 photoresist-derived electrospun carbon nanofibres as high ...

    Indian Academy of Sciences (India)

    2017-06-09

    Jun 9, 2017 ... as high-capacity anode material for lithium ion battery. M KAKUNURI, S KAUSHIK, A SAINI and C S SHARMA. ∗. Creative and Advanced Research Based On Nanomaterials (CARBON) Laboratory, Department of Chemical Engineering,. Indian Institute of Technology, Hyderabad, Kandi 502285, India. ∗.

  2. SU-8 photoresist-derived electrospun carbon nanofibres as high ...

    Indian Academy of Sciences (India)

    ... Refresher Courses · Symposia · Live Streaming. Home; Journals; Bulletin of Materials Science; Volume 40; Issue 3. SU-8 photoresist-derived electrospun carbon nanofibres as high-capacity anode material for lithium ion battery. M KAKUNURI S KAUSHIK A SAINI C S SHARMA. Volume 40 Issue 3 June 2017 pp 435-439 ...

  3. Cavitation-induced reactions in high-pressure carbon dioxide

    NARCIS (Netherlands)

    Kuijpers, M.W.A.; van Eck, D.; Kemmere, M.F.; Keurentjes, J.T.F.

    2002-01-01

    The feasibility of ultrasound-induced in situ radical formation in liquid carbon dioxide was demonstrated. The required threshold pressure for cavitation could be exceeded at a relatively low acoustic intensity, as the high vapor pressure of CO2 counteracts the hydrostatic pressure. With the use of

  4. High-performance carbon nanotube-reinforced bioplastic

    CSIR Research Space (South Africa)

    Ramontja, J

    2009-12-01

    Full Text Available -1 High-Performance Carbon Nanotube-Reinforced Bioplastic 1. James Ramontja1,2, 2. Suprakas Sinha Ray1,*, 3. Sreejarani K. Pillai1, 4. Adriaan S. Luyt2 1. 1 DST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials...

  5. Distribution of black carbon in Ponderosa pine litter and soils following the High Park wildfire

    Science.gov (United States)

    Boot, C. M.; Haddix, M.; Paustian, K.; Cotrufo, M. F.

    2014-12-01

    Black carbon (BC), the heterogeneous product of burned biomass, is a critical component in the global carbon cycle, yet timescales and mechanisms for incorporation into the soil profile are not well understood. The High Park Fire, which took place in northwestern Colorado in the summer of 2012, provided an opportunity to study the effects of both fire intenstiy and geomorphology on properties of carbon (C), nitrogen (N), and BC in the Cache La Poudre River drainage. We sampled montane Ponderosa pine litter, 0-5 cm soils, and 5-15 cm soils four months post-fire in order to examine the effects of slope and burn intensity on %C, C stocks, %N and black carbon (g kg-1 C, and g m-2). We developed and implemented the benzene polycarboxylic acid (BPCA) method for quantifying BC. With regard to slope, we found that steeper slopes had higher C : N than shallow slopes, but that there was no difference in black carbon content or stocks. BC content was greatest in the litter in burned sites (19 g kg-1 C), while BC stocks were greatest in the 5-15 cm subsurface soils (23 g m-2). At the time of sampling, none of the BC deposited on the land surface post-fire had been incorporated into to either the 0-5 cm or 5-15 cm soil layers. The ratio of B5CA : B6CA (less condensed to more condensed BC) indicated there was significantly more older, more processed BC at depth. Total BC soil stocks were relatively low compared to other fire-prone grassland and boreal forest systems, indicating most of the BC produced in this system is likely transported off the surface through erosion events. Future work examining mechanisms for BC transport will be required for understanding the role BC plays in the global carbon cycle.

  6. Turbulent Flame Propagation Characteristics of High Hydrogen Content Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Seitzman, Jerry [Georgia Inst. of Technology, Atlanta, GA (United States); Lieuwen, Timothy [Georgia Inst. of Technology, Atlanta, GA (United States)

    2014-09-30

    This final report describes the results of an effort to better understand turbulent flame propagation, especially at conditions relevant to gas turbines employing fuels with syngas or hydrogen mixtures. Turbulent flame speeds were measured for a variety of hydrogen/carbon monoxide (H2/CO) and hydrogen/methane (H2/CH4) fuel mixtures with air as the oxidizer. The measurements include global consumption speeds (ST,GC) acquired in a turbulent jet flame at pressures of 1-10 atm and local displacement speeds (ST,LD) acquired in a low-swirl burner at atmospheric pressure. The results verify the importance of fuel composition in determining turbulent flame speeds. For example, different fuel-air mixtures having the same unstretched laminar flame speed (SL,0) but different fuel compositions resulted in significantly different ST,GC for the same turbulence levels (u'). This demonstrates the weakness of turbulent flame speed correlations based simply on u'/SL,0. The results were analyzed using a steady-steady leading points concept to explain the sensitivity of turbulent burning rates to fuel (and oxidizer) composition. Leading point theories suggest that the premixed turbulent flame speed is controlled by the flame front characteristics at the flame brush leading edge, or, in other words, by the flamelets that advance farthest into the unburned mixture (the so-called leading points). For negative Markstein length mixtures, this is assumed to be close to the maximum stretched laminar flame speed (SL,max) for the given fuel-oxidizer mixture. For the ST,GC measurements, the data at a given pressure were well-correlated with an SL,max scaling. However the variation with pressure was not captured, which may be due to non-quasi-steady effects that are not included in the current model. For the ST,LD data, the leading points model again faithfully captured the variation of turbulent flame speed over a wide range of fuel-compositions and turbulence intensities. These

  7. High purity heavy water production: need for total organic carbon determination in process water streams

    International Nuclear Information System (INIS)

    Ayushi; Kumar, Sangita D.; Reddy, A.V.R.; Vithal, G.K.

    2009-01-01

    In recent times, demand for high purity heavy water (99.98% pure) in industries and laboratories has grown by manifold. Its application started in nuclear industry with the design of CANDU reactor, which uses natural uranium as fuel. In this reactor the purest grade of heavy water is used as the moderator and the primary coolant. Diverse industrial applications like fibre optics, medicine, semiconductors etc. use high purity heavy water extensively to achieve better performance of the specific material. In all these applications there is a stringent requirement that the total organic carbon content (TOC) of high purity heavy water should be very low. This is because the presence of TOC can lead to adverse interactions in different applications. To minimize the TOC content in the final product there is a need to monitor and control the TOC content at each and every stage of heavy water production. Hence a simple, rapid and accurate method was developed for the determination of TOC content in process water samples. The paper summarizes the results obtained for the TOC content in the water samples collected from process streams of heavy water production plant. (author)

  8. NOVEL CERAMIC MEMBRANE FOR HIGH TEMPERATURE CARBON DIOXIDE SEPARATION; SEMIANNUAL

    International Nuclear Information System (INIS)

    Jerry Y.S. Lin; Jun-ichi Ida

    2001-01-01

    This project is aimed at demonstrating technical feasibility for a lithium zirconate based dense ceramic membrane for separation of carbon dioxide from flue gas at high temperature. The research work conducted in this reporting period was focused on several fundamental issues of lithium zirconate important to the development of the dense inorganic membrane. These fundamental issues include material synthesis of lithium zirconate, phases and microstructure of lithium zirconate and structure change of lithium zirconate during sorption/desorption process. The results show difficulty to prepare the dense ceramic membrane from pure lithium zirconate, but indicate a possibility to prepare the dense inorganic membrane for carbon dioxide separation from a composite lithium zirconate

  9. Determination of vanadium in high grade carbons by radioanalytical methods

    International Nuclear Information System (INIS)

    Jinno, K.; Sato, M.; Amemiya, S.; Katoh, T.

    1980-01-01

    The present work deals with the determination of vanadium in high grade carbons by three radioanalytical methods, viz. thermal neutron activation analysis with an accelerator, thermal neutron activation analysis with a reactor and proton induced X-ray emission analysis with an accelerator. It is shown that thermal neutron activation with an accelerator is more convenient for the rapid and non-destructive analysis of ppm-level vanadium in bulk carbons than thermal neutron activation analysis with a reactor. Proton-induced X-ray emission is less useful for the analysis of bulk samples. (author)

  10. Social Network and Content Analysis of the North American Carbon Program as a Scientific Community of Practice

    Science.gov (United States)

    Brown, Molly E.; Ihli, Monica; Hendrick, Oscar; Delgado-Arias, Sabrina; Escobar, Vanessa M.; Griffith, Peter

    2015-01-01

    The North American Carbon Program (NACP) was formed to further the scientific understanding of sources, sinks, and stocks of carbon in Earth's environment. Carbon cycle science integrates multidisciplinary research, providing decision-support information for managing climate and carbon-related change across multiple sectors of society. This investigation uses the conceptual framework of com-munities of practice (CoP) to explore the role that the NACP has played in connecting researchers into a carbon cycle knowledge network, and in enabling them to conduct physical science that includes ideas from social science. A CoP describes the communities formed when people consistently engage in shared communication and activities toward a common passion or learning goal. We apply the CoP model by using keyword analysis of abstracts from scientific publications to analyze the research outputs of the NACP in terms of its knowledge domain. We also construct a co-authorship network from the publications of core NACP members, describe the structure and social pathways within the community. Results of the content analysis indicate that the NACP community of practice has substantially expanded its research on human and social impacts on the carbon cycle, contributing to a better understanding of how human and physical processes interact with one another. Results of the co-authorship social network analysis demonstrate that the NACP has formed a tightly connected community with many social pathways through which knowledge may flow, and that it has also expanded its network of institutions involved in carbon cycle research over the past seven years.

  11. Non-combustible nuclear radiation shields with high hydrogen content

    International Nuclear Information System (INIS)

    Hall, W.C.; Peterson, J.M.

    1978-01-01

    The invention relates to compositions, methods of production, and uses of non-combustible nuclear radiation shields, with particular emphasis on those containing a high concentration of hydrogen atoms, especially effective for moderating neutron energy by elastic scatter, dispersed as a discontinuous phase in a continuous phase of a fire resistant matrix

  12. An Introduction to Computing: Content for a High School Course.

    Science.gov (United States)

    Rogers, Jean B.

    A general outline of the topics that might be covered in a computers and computing course for high school students is provided. Topics are listed in the order in which they should be taught, and the relative amount of time to be spent on each topic is suggested. Seven units are included in the course outline: (1) general introduction, (2) using…

  13. Discharge efficiency in high-Xe-content plasma display panels

    NARCIS (Netherlands)

    Hayashi, D.; Kroesen, G.M.W.; Hagelaar, G.J.M.; Heusler, G.

    2004-01-01

    We study theoretically the overall output performance and the dominating reaction processes of the vacuum ultraviolet (UV) radiation production in high-Xe partial pressures in plasma display panels (PDPs) with Ne-Xe gas mixtures. A two-dimensional self-consistent fluid model is applied for the

  14. Carbonation by fluid-rock interactions at high-pressure conditions: Implications for carbon cycling in subduction zones

    Science.gov (United States)

    Piccoli, Francesca; Vitale Brovarone, Alberto; Beyssac, Olivier; Martinez, Isabelle; Ague, Jay J.; Chaduteau, Carine

    2016-07-01

    Carbonate-bearing lithologies are the main carbon carrier into subduction zones. Their evolution during metamorphism largely controls the fate of carbon, regulating its fluxes between shallow and deep reservoirs. Recent estimates predict that almost all subducted carbon is transferred into the crust and lithospheric mantle during subduction metamorphism via decarbonation and dissolution reactions at high-pressure conditions. Here we report the occurrence of eclogite-facies marbles associated with metasomatic systems in Alpine Corsica (France). The occurrence of these marbles along major fluid-conduits as well as textural, geochemical and isotopic data indicating fluid-mineral reactions are compelling evidence for the precipitation of these carbonate-rich assemblages from carbonic fluids during metamorphism. The discovery of metasomatic marbles brings new insights into the fate of carbonic fluids formed in subducting slabs. We infer that rock carbonation can occur at high-pressure conditions by either vein-injection or chemical replacement mechanisms. This indicates that carbonic fluids produced by decarbonation reactions and carbonate dissolution may not be directly transferred to the mantle wedge, but can interact with slab and mantle-forming rocks. Rock-carbonation by fluid-rock interactions may have an important impact on the residence time of carbon and oxygen in subduction zones and lithospheric mantle reservoirs as well as carbonate isotopic signatures in subduction zones. Furthermore, carbonation may modulate the emission of CO2 at volcanic arcs over geological time scales.

  15. Comparison of sample digestion techniques for the determination of trace and residual catalyst metal content in single-wall carbon nanotubes by inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Grinberg, Patricia, E-mail: patricia.grinberg@nrc.ca [Measurement Science and Standards, National Research Council Canada, Ottawa (Canada); Sturgeon, Ralph E. [Measurement Science and Standards, National Research Council Canada, Ottawa (Canada); Diehl, Liange de O.; Bizzi, Cezar A. [Measurement Science and Standards, National Research Council Canada, Ottawa (Canada); Chemistry Department, Universidade Federal de Santa Maria, Santa Maria (Brazil); Flores, Erico M.M. [Chemistry Department, Universidade Federal de Santa Maria, Santa Maria (Brazil)

    2015-03-01

    A single-wall carbon nanotube material produced by laser ablation of renewable biochar in the presence of Ni and Co catalyst was characterized for residual catalyst (Co and Ni) as well as trace metal impurity content (Fe, Mo, Cr, Pb and Hg) by isotope dilution ICP-MS following sample digestion. Several matrix destruction procedures were evaluated, including a multi-step microwave-assisted acid digestion, dry ashing at 450 °C and microwave-induced combustion with oxygen. Results were benchmarked against those derived from neutron activation analysis and also supported by solid sampling continuum source GF-AAS for several of the elements. Although laborious to execute, the multi-step microwave-assisted acid digestion proved to be most reliable for recovery of the majority of the analytes, although content of Cr remained biased low for each approach, likely due to its presence as refractory carbide. - Highlights: • Determination of trace and residual catalyst metal content in Single-Wall Carbon Nanotubes by Inductively Coupled Plasma Mass Spectrometry. • Comparative study of digestion methodology combined with high precision isotope dilution ICP-MS for quantitation of elements of toxicologic relevance. • Results were benchmarked against those derived from neutron activation analysis and also supported by solid sampling continuum source GF-AAS for several of the elements.

  16. The Use of Ameliorant Fe3+ and Rock Phosphates in Peat Soil at Several Water Condition on the P Content of Plants Rice and Carbon Emission

    Directory of Open Access Journals (Sweden)

    Nelvia

    2009-09-01

    Full Text Available The addition of ameliorant Fe3+ and rock phosphates containing high Fe cation can reduce effect of toxic organic acids, increase peat stability through formation of complex compounds and reduce carbon emission. The research was conducted in the laboratory and green house of the Departement of Soil Science, Faculty of Agriculture, Bogor Agriculture University. Peat samples with hemic degree of decomposition were taken from Riau. Rock phosphates were taken from the rock phosphates of PT. Petrokimia Gresik, Christmas Island phosphates, and Huinan China and FeCl3.6H2O was used as the other Fe3+ source. The aims of the research were to study (a the effect of the applications of ameliorant Fe3+ and rock phosphates on the P content of plants dan (b the effect of the application ameliorant Fe3+ and the contribution of Fe cation in rock phosphates in the decrease of carbon emission. The results showed that the P content of plants rice increased 58 – 286% with the applications of ameliorant Fe3+ and rock phosphates. The estimation of carbon loss through CO2 and CH4 emissions from peats if planted continuously with rice was around 2.5, 2.2 and 2.6 Mg of C ha-1 year-1 respectively in field capacity condition, two times of field capacity condition, and 5 cm of saturated condition. The application of ameliorant Fe3+ and rock phosphates containing high Fe cation increased the stability of peats and reduced the carbon loss around 1.7 Mg of C ha-1 year-1 (64% in 5 cm of saturated condition, 1.3 Mg of C ha-1 year-1 (58% in two times of field capacity condition, and 1.0 Mg of C ha-1 year-1 (41% in field capacity condition.

  17. High temperature SU-8 pyrolysis for fabrication of carbon electrodes

    DEFF Research Database (Denmark)

    Hassan, Yasmin Mohamed; Caviglia, Claudia; Hemanth, Suhith

    2017-01-01

    In this work, we present the investigation of the pyrolysis parameters at high temperature (1100 °C) for the fabrication of two-dimensional pyrolytic carbon electrodes. The electrodes were fabricated by pyrolysis of lithographically patterned negative epoxy based photoresist SU-8. A central...... composite experimental design was used to identify the influence of dwell time at the highest pyrolysis temperature and heating rate on electrical, electrochemical and structural properties of the pyrolytic carbon: Van der Pauw sheet resistance measurements, cyclic voltammetry, electrochemical impedance...... spectroscopy and Raman spectroscopy were used to characterize the pyrolytic carbon. The results show that the temperature increase from 900 °C to 1100 °C improves the electrical and electrochemical properties. At 1100 °C, longer dwell time leads to lower resistivity, while the variation of the pyrolysis...

  18. Highly Efficient Catalytic Cyclic Carbonate Formation by Pyridyl Salicylimines.

    Science.gov (United States)

    Subramanian, Saravanan; Park, Joonho; Byun, Jeehye; Jung, Yousung; Yavuz, Cafer T

    2018-03-21

    Cyclic carbonates as industrial commodities offer a viable nonredox carbon dioxide fixation, and suitable heterogeneous catalysts are vital for their widespread implementation. Here, we report a highly efficient heterogeneous catalyst for CO 2 addition to epoxides based on a newly identified active catalytic pocket consisting of pyridine, imine, and phenol moieties. The polymeric, metal-free catalyst derived from this active site converts less-reactive styrene oxide under atmospheric pressure in quantitative yield and selectivity to the corresponding carbonate. The catalyst does not need additives, solvents, metals, or co-catalysts, can be reused at least 10 cycles without the loss of activity, and scaled up easily to a kilogram scale. Density functional theory calculations reveal that the nucleophilicity of pyridine base gets stronger due to the conjugated imines and H-bonding from phenol accelerates the reaction forward by stabilizing the intermediate.

  19. Carbon nanotubes as nanotexturing agents for high power supercapacitors based on seaweed carbons.

    Science.gov (United States)

    Raymundo-Piñero, Encarnación; Cadek, Martin; Wachtler, Mario; Béguin, François

    2011-07-18

    The advantages provided by multiwalled carbon nanotubes (CNTs) as backbones for composite supercapacitor electrodes are discussed. This paper particularly highlights the electrochemical properties of carbon composites obtained by pyrolysis of seaweed/CNTs blends. Due to the nanotexturing effect of CNTs, supercapacitors fabricated with electrodes from these composites exhibit enhanced electrochemical performances compared with CNT-free carbons. The cell resistance is dramatically reduced by the excellent conductivity of CNTs and by the good propagation of ions favored by the presence of opened mesopores. As a consequence, the specific power of supercapacitors based on these nanocomposites is very high. Another advantage related to the presence of CNTs is a better life cycle of the systems. The composite electrodes are resilient during the charge/discharge of capacitors; these are able to perfectly accommodate the dimensional changes appearing in the active material without mechanical damages. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. High-energy, short-pulse, carbon-dioxide lasers

    International Nuclear Information System (INIS)

    Fenstermacher, C.A.

    1979-01-01

    Lasers for fusion application represent a special class of short-pulse generators; not only must they generate extremely short temporal pulses of high quality, but they must do this at ultra-high powers and satisfy other stringent requirements by this application. This paper presents the status of the research and development of carbon-dioxide laser systems at the Los Alamos Scientific Laboratory, vis-a-vis the fusion requirements

  1. Dynamic carbon content as an indicator of desertification processes in soils developed from volcanic parental material in the Region of Murcia

    International Nuclear Information System (INIS)

    Martinez-Martinez, S.; Faz Cano, A.; Acosta Aviles, J. A.

    2009-01-01

    Soil Organic Carbon (SOC is an essential components of the global carbon cycle, especially in soils developed from volcanic rocks, due to these soils does not have inorganic carbon. In arid and semiarid areas mineralization of organic carbon is very intense due to climatic conditions, causing soils depletion and therefore desertification. The objective of this study is to determine the content of OC, as a first step in the assessment of desertification. The objective of this study is to determine the content of OC, as a first step in the assessment of desertification processes affecting this area of the southeast of Spain. (Author) 7 refs.

  2. Immediate analysis of the oil content of seeds by carbon-13 nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Leal, K Z; Costa, V E.U.; Seidl, P R; Campos, M P.A.; Colnago, L A [Instituto Militar de Engenharia, Rio de Janeiro (Brazil). Secao de Quimica

    1981-11-01

    The carbon 13 nuclear magnetic resonance (CMR) spectra of a series of Brazilian oilseeds was registered. The main constituents of the oils are identified and signals for each carbon atom are assigned. Chemical shifts are estimated for the free fatty acids and compared to those observed from the seeds, with good results. Besides being non-destructive, the RMC method proves to be fast and is useful in the determination of the principal components of the oil fraction of different types of seeds.

  3. Calcium content of different compositions of gallstones and pathogenesis of calcium carbonate gallstones

    Directory of Open Access Journals (Sweden)

    Ji-Kuen Yu

    2013-01-01

    Conclusion: From our study, we found chronic and/or intermittent cystic duct obstructions and low-grade GB wall inflammation lead to GB epithelium hydrogen secretion dysfunction. Increased calcium ion efflux into the GB lumen combined with increased carbonate anion presence increases SI_CaCO3 from 1 to 22.4. Thus, in an alkaline milieu with pH 7.8, calcium carbonate begins to aggregate and precipitate.

  4. Performance of CVD and CVR coated carbon-carbon in high temperature hydrogen

    Science.gov (United States)

    Adams, J. W.; Barletta, R. E.; Svandrlik, J.; Vanier, P. E.

    As a part of the component development process for the particle bed reactor (PBR), it is necessary to develop coatings which will be time and temperature stable at extremely high temperatures in flowing hydrogen. These coatings must protect the underlying carbon structure from attack by the hydrogen coolant. Degradation which causes small changes in the reactor component, e.g. hole diameter in the hot frit, can have a profound effect on operation. The ability of a component to withstand repeated temperature cycles is also a coating development issue. Coatings which crack or spall under these conditions would be unacceptable. While refractory carbides appear to be the coating material of choice for carbon substrates being used in PBR components, the method of applying these coatings can have a large effect on their performance. Two deposition processes for these refractory carbides, chemical vapor deposition (CVD) and chemical vapor reaction (CVR), have been evaluated. Screening tests for these coatings consisted of testing of coated 2-D and 3-D weave carbon-carbon in flowing hot hydrogen at one atmosphere. Carbon loss from these samples was measured as a function of time. Exposure temperatures up to 3,000 K were used, and samples were exposed in a cyclical fashion cooling to room temperature between exposures. The results of these measurements are presented along with an evaluation of the relative merits of CVR and CVD coatings for this application.

  5. A Raman Study of Carbonates and Organic Contents in Five CM Chondrites

    Science.gov (United States)

    Chan, Q. H. S.; Zolensky, M. E.; Bodnar, R. J.; Farley, C.; Cheung, J. C. H.

    2016-01-01

    Carbonates comprise the second most abundant class of carbon-bearing phases in carbonaceous chondrites after organic matter (approximately 2 wt.%), followed by other C-bearing phases such as diamond, silicon carbide, and graphite. Therefore, understanding the abundances of carbonates and the associated organic matter provide critical insight into the genesis of major carbonaceous components in chondritic materials. Carbonates in CM chondrites mostly occur as calcite (of varying composition) and dolomite. Properly performed, Raman spectroscopy provides a non-destructive technique for characterizing meteorite mineralogy and organic chemistry. It is sensitive to many carbonaceous phases, allows the differentiation of organic from inorganic materials, and the interpretation of their spatial distribution. Here, with the use of Raman spectroscopy, we determine the structure of the insoluble organic matter (IOM) in the matrix and carbonate phases in five CM chondrites: Jbilet Winselwan, Murchison, Nogoya, Santa Cruz, and Wisconsin Range (WIS) 91600, and interpret the relative timing of carbonate precipitation and the extent of the associated alteration events.

  6. Fully Biodegradable Biocomposites with High Chicken Feather Content

    OpenAIRE

    Aranberri, Ibon; Montes, Sarah; Azcune, Itxaso; Rekondo, Alaitz; Grande, Hans-Jürgen

    2017-01-01

    The aim of this work was to develop new biodegradable polymeric materials with high loadings of chicken feather (CF). In this study, the effect of CF concentration and the type of biodegradable matrix on the physical, mechanical and thermal properties of the biocomposites was investigated. The selected biopolymers were polylactic acid (PLA), polybutyrate adipate terephthalate (PBAT) and a PLA/thermoplastic copolyester blend. The studied biocomposites were manufactured with a to...

  7. Effect of total cementitious content on shear strength of high-volume fly ash concrete beams

    International Nuclear Information System (INIS)

    Arezoumandi, Mahdi; Volz, Jeffery S.; Ortega, Carlos A.; Myers, John J.

    2013-01-01

    Highlights: ► Existing design standards conservatively predicted the capacity of the HVFAC beams. ► In general, the HVFAC beams exceeded the code predicted shear strengths. ► The cementitious content did not have effect on the shear behavior of the HVFAC beams. - Abstract: The production of portland cement – the key ingredient in concrete – generates a significant amount of carbon dioxide. However, due to its incredible versatility, availability, and relatively low cost, concrete is the most consumed manmade material on the planet. One method of reducing concrete’s contribution to greenhouse gas emissions is the use of fly ash to replace a significant amount of the cement. This paper compares two experimental studies that were conducted to investigate the shear strength of full-scale beams constructed with high-volume fly ash concrete (HVFAC) – concrete with at least 50% of the cement replaced with fly ash. The primary difference between the two studies involved the amount of cementitious material, with one mix having a relatively high total cementitious content (502 kg/m 3 ) and the other mix having a relatively low total cementitious content (337 kg/m 3 ). Both mixes utilized a 70% replacement of portland cement with a Class C fly ash. Each of these experimental programs consisted of eight beams (six without shear reinforcing and two with shear reinforcing in the form of stirrups) with three different longitudinal reinforcement ratios. The beams were tested under a simply supported four-point loading condition. The experimental shear strengths of the beams were compared with both the shear provisions of selected standards (US, Australia, Canada, Europe, and Japan) and a shear database of conventional concrete (CC) specimens. Furthermore, statistical data analyses (both parametric and nonparametric) were performed to evaluate whether or not there is any statistically significant difference between the shear strength of both mixes. Results of these

  8. Microstructure Characteristics of High Lift Factor MOCVD REBCO Coated Conductors With High Zr Content

    Energy Technology Data Exchange (ETDEWEB)

    Galstyan, E; Gharahcheshmeh, MH; Delgado, L; Xu, AX; Majkic, G; Selvamanickam, V

    2015-06-01

    We report the microstructural characteristics of high levels of Zr-added REBa2Cu3O7-x (RE = Gd, Y rare earth) coated conductors fabricated by Metal Organic Chemical Vapor Deposition (MOCVD). The enhancements of the lift factor defined as a ratio of the in-field (3 T, B parallel to c-axis) critical current density (J(c)) at 30 K and self-field J(c) at 77 K have been achieved for Zr addition levels of 20 and 25 mol% via optimization of deposition parameters. The presence of strong flux pinning is attributed to the aligned nanocolumns of BaZrO3 and nanoprecipitates embedded in REBa2Cu3O7-x matrix with good crystal quality. A high density of BZO nanorods with a typical size 6-8 nm and spacing of 20 nm has been observed. Moreover, the high Zr content was found to induce a high density of intrinsic defects, including stacking faults and dislocations. The correlation between in-field performance along the c-axis and microstructure of (Gd, Y) BCO film with a high level of Zr addition is discussed.

  9. Retrogradation of Maize Starch after High Hydrostatic Pressure Gelation: Effect of Amylose Content and Depressurization Rate

    KAUST Repository

    Yang, Zhi; Swedlund, Peter; Gu, Qinfen; Hemar, Yacine; Chaieb, Saharoui

    2016-01-01

    High hydrostatic pressure (HHP) has been employed to gelatinize or physically modify starch dispersions. In this study, waxy maize starch, normal maize starch, and two high amylose content starch were processed by a HHP of the order of 600 MPa

  10. Development of Low Carbon Niobium Bearing High Strength F-B Dual Phase Steel with High Hole Expansion Property

    Science.gov (United States)

    Zhang, Lin; Xia, Ming-sheng; Xiong, Zi-liu; Du, Yan-bing; Qiao, Zhi-ming; Zhang, Hong-bo

    In the study a low carbon niobium bearing high strength F-B dual phase automobile steel with high hole expansion property has been investigated. Steels of different chemical composition have been investigated by simulation experiments of controlled rolling and cooling process to study the influences of chemical elements, especially for C,Nb and Ti, and cooling pattern on the mechanical properties, flangeability and microstructure of strips. So-called 3-stages cooling pattern was adopted in simulation experiments, combining ultra fast cooling in first stage, air cooling in middle stage and fast cooling in the last stage, and at the end of run-out table the temperature of rolled pieces drop to below Bs point. Optical microstructure and SEM morphology have been observed. Results indicate that it is possible to obtain dual phase microstructure of polygonal ferrite plus bainite in adopting 3-stages cooling pattern. The low temperature coiling method using 3-step controlled cooling pattern after hot rolling is effective to produce low carbon Nb bearing steel with high balance of strength-ductility-flangeability, in addition, higher carbon content of steel tend to be detrimental to flangeability of steel, due to much carbide precipitation at ferrite boundary. Based on the results of simulation experiments mill trial has been carried out and hot rolled high strength steel with tensile strength higher as 600Mpa and hole expansion ratio higher as 100% has been developed successfully.

  11. Highly Flexible Freestanding Porous Carbon Nanofibers for Electrodes Materials of High-Performance All-Carbon Supercapacitors.

    Science.gov (United States)

    Liu, Ying; Zhou, Jinyuan; Chen, Lulu; Zhang, Peng; Fu, Wenbin; Zhao, Hao; Ma, Yufang; Pan, Xiaojun; Zhang, Zhenxing; Han, Weihua; Xie, Erqing

    2015-10-28

    Highly flexible porous carbon nanofibers (P-CNFs) were fabricated by electrospining technique combining with metal ion-assistant acid corrosion process. The resultant fibers display high conductivity and outstanding mechanical flexibility, whereas little change in their resistance can be observed under repeatedly bending, even to 180°. Further results indicate that the improved flexibility of P-CNFs can be due to the high graphitization degree caused by Co ions. In view of electrode materials for high-performance supercapacitors, this type of porous nanostructure and high graphitization degree could synergistically facilitate the electrolyte ion diffusion and electron transportation. In the three electrodes testing system, the resultant P-CNFs electrodes can exhibit a specific capacitance of 104.5 F g(-1) (0.2 A g(-1)), high rate capability (remain 56.5% at 10 A g(-1)), and capacitance retention of ∼94% after 2000 cycles. Furthermore, the assembled symmetric supercapacitors showed a high flexibility and can deliver an energy density of 3.22 Wh kg(-1) at power density of 600 W kg(-1). This work might open a way to improve the mechanical properties of carbon fibers and suggests that this type of freestanding P-CNFs be used as effective electrode materials for flexible all-carbon supercapacitors.

  12. High carotenoids content can enhance resistance of selected Pinctada fucata families to high temperature stress.

    Science.gov (United States)

    Meng, Zihao; Zhang, Bo; Liu, Baosuo; Li, Haimei; Fan, Sigang; Yu, Dahui

    2017-02-01

    Carotenoids are a class of natural antioxidants widely found in aquatic, and they have significant effects on the growth, survival, and immunity of these organisms. To investigate the mechanisms of carotenoids in high temperature resistance, we observed the immune response of selected pearl oyster Pinctada fucata (Akoya pearl oyster) families with different carotenoids contents to high temperature stress. The results indicated that the survival rate (SR) of P. fucata decreased significantly with increase in temperature from 26 °C to 34 °C and with the decrease of total carotenoids content (TCC); when the TCC was higher, the SR tended to be higher. TCC and total antioxidant capacity (TAC) decreased significantly at 30 °C with increasing stress time. Correlation analysis indicated that TAC was positively and linearly correlated with TCC, and SR was S-type correlated with TCC and TAC. Immune analysis indicated that levels of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) in selected families (with higher TCC) under temperature stress (at 30 °C) were generally significantly lower than in the control group (with lowest TCC) and from 0 to 96 h, the levels of each of these substances varied significantly. Levels of SOD, CAT, and MDA within each family first rose from 0 to 3 h, then decreased to their lowest point after 24 h, and then rose again to their highest levels at 96 h. When TCC was higher, the levels of SOD, CAT, and MDA tended to be lower. These findings indicated that carotenoids play an important role in improving survival rates of P. fucata under high temperature stress by enhancing animals' antioxidant system, and could serve as an index for breeding stress-resistant lines in selective breeding practices. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Rapid recovery of high content phytosterols from corn silk.

    Science.gov (United States)

    Zhang, Haiyan; Cao, Xiaowan; Liu, Yong; Shang, Fude

    2017-10-18

    Phytosterols have important physiological and officinal function. An efficient ultrasonic assisted extraction, purification and crystallization procedure of phytosterols was established from corn silk for the first time. The orthogonal test was applied to optimize the process parameters and a maximum phytosterols recovery as high as 10.5886 mg/g was achieved by ultrasonic treatment for 55 min with liquid-solid ratio of 12:1 at 35 °C, 220 w. The ultrasonic extraction temperature (T, °C) has the most significant effect on extraction yield of phytosterols. An orthogonal crystallization test was performed and the optimal conditions [crystallization temperature of 8 °C, time of 12 h and solid-liquid ratio of 1:1 (g/ml)] afforded maximum phytosterols purity of 92.76 ± 0.43%. An efficient extraction and crystallization procedure was established.

  14. Can the water content of highly compacted bentonite be increased by applying a high water pressure?

    International Nuclear Information System (INIS)

    Pusch, R.; Kasbohm, J.

    2001-10-01

    A great many laboratory investigations have shown that the water uptake in highly compacted MX-80 clay takes place by diffusion at low external pressure. It means that wetting of the clay buffer in the deposition holes of a KBS-3 repository is very slow if the water pressure is low and that complete water saturation can take several tens of years if the initial degree of water saturation of the buffer clay and the ability of the rock to give off water are low. It has therefore been asked whether injection of water can raise the degree of water saturation and if a high water pressure in the nearfield can have the same effect. The present report describes attempts to moisten highly compacted blocks of MX-80 clay with a dry density of 1510 kg/m 3 by injecting water under a pressure of 650 kPa through a perforated injection pipe for 3 and 20 minutes, respectively. The interpretation was made by determining the water content of a number of samples located at different distances from the pipe. An attempt to interpret the pattern of distribution of injected uranium acetate solution showed that the channels into which the solution went became closed in a few minutes and that dispersion in the homogenized clay gave low U-concentrations. The result was that the water content increased from about 9 to about 11-12 % within a distance of about 1 centimeter from the injection pipe and to slightly more than 9 % at a distance of about 4-5 cm almost independently of the injection time. Complete water saturation corresponds to a water content of about 30 % and the wetting effect was hence small from a practical point of view. By use of microstructural models it can be shown that injected water enters only the widest channels that remain after the compaction and that these channels are quickly closed by expansion of the hydrating surrounding clay. Part of the particles that are thereby released become transported by the flowing water and cause clogging of the channels, which is

  15. Achieving high performance in intermediate temperature direct carbon fuel cells with renewable carbon as a fuel source

    International Nuclear Information System (INIS)

    Hao, Wenbin; He, Xiaojin; Mi, Yongli

    2014-01-01

    Highlights: • Bamboo fiber and waste paper were pyrolyzed to generate bamboo carbon and waste paper carbon as anode fuels of IT-DCFC. • Superior cell performance was achieved with the waste paper carbon. • The results suggested the high performance was due to the highest thermal reactivity and the catalytic inherent impurities. • Calcite and kaolinite as inherent impurities favored the thermal decomposition and the electrooxidation of carbon. - Abstract: Three kinds of carbon sources obtained from carbon black, bamboo fiber and waste paper were investigated as anode fuels in an intermediate temperature direct carbon fuel cell. The carbon sources were characterized with X-ray photoelectron spectroscopy, thermal gravimetric analysis, etc. The results indicated that the waste paper carbon was more abundant in calcite and kaolinite, and showed higher thermal reactivity in the intermediate temperature range compared with the other two carbon sources. The cell performance was tested at 650 °C in a hybrid single cell, using Sm 0.20 Ce 0.80 O 2−x as the electrolyte. As a result, the cell fed with waste paper carbon showed the highest performance among the three carbon sources, with a peak power density of 225 mW cm −2 . The results indicated that its inherent impurities, such as calcite and kaolinite, might favor the thermal gasification of renewable carbon sources, which resulted in the enhanced performance of the intermediate temperature direct carbon fuel cell

  16. Carbon partitioning in the food web of a high mountain lake: from bacteria to zooplankton

    Directory of Open Access Journals (Sweden)

    Alessandra PUGNETTI

    1999-08-01

    Full Text Available The organisms of the microbial loop in Lake Paione Superiore (LPS, a high mountain lake in the Italian Alpine region, were studied together with phytoplankton and zooplankton for three successive years. The biomass of bacteria, HNF (heterotrophic nanoflagellates, ciliates and phytoplankton, as mean carbon concentration in the three years, was 30 and 37 μg C l-1 near the surface (SUR and the bottom (BOT respectively. Under the ice-cover the mean biomass carbon decreased especially at the BOT, whereas at SUR the decrease was less evident due to the maintenance of higher phytoplankton biomass (mixotrophic flagellates. In LPS ~50% of the carbon was confined in bacteria, 20% in protozoa and 30% in phytoplankton. The ratio Autotrophs/Heterotrophs was lower than 1 (mean: 0,97 at SUR and 0,58 at BOT thus indicating a system with a predominance of the heterotrophs. This might be the result of light inhibition of algal growth coupled to a production of dissolved carbon, utilized by bacteria. During late summer the peak of Daphnia longispina, the main component of the zooplankton of LPS, increased the carbon content in the lake to a total of 158 and 300 μg C l-1 in 1997 and 1998 respectively. At the late summer peaks, zooplankton represented from 78 to 89% of the total carbon of the pelagic communities. Furthermore, the presence of Daphnia could be responsible for a decrease in the biomass carbon of a variety of organisms (algae, protozoa and bacteria. It may be possible that this is an instance of zooplankton grazing on algae, protozoa and also bacteria, as Daphnia has very broad niches and may eat pico-, nanoplankton and small ciliates. In the oligotrophic LPS, a diet which also includes protozoa could give Daphnia a further chance of survival, as ciliates are an important source of fatty acids and sterols.

  17. Arabidopsis thaliana ggt1 photorespiratory mutants maintain leaf carbon/nitrogen balance by reducing RuBisCO content and plant growth.

    Science.gov (United States)

    Dellero, Younès; Lamothe-Sibold, Marlène; Jossier, Mathieu; Hodges, Michael

    2015-09-01

    Metabolic and physiological analyses of glutamate:glyoxylate aminotransferase 1 (GGT1) mutants were performed at the global leaf scale to elucidate the mechanisms involved in their photorespiratory growth phenotype. Air-grown ggt1 mutants showed retarded growth and development, that was not observed at high CO2 (3000 μL L(-1) ). When compared to wild-type (WT) plants, air-grown ggt1 plants exhibited glyoxylate accumulation, global changes in amino acid amounts including a decrease in serine content, lower organic acid levels, and modified ATP/ADP and NADP(+) /NADPH ratios. When compared to WT plants, their net CO2 assimilation rates (An ) were 50% lower and this mirrored decreases in ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) contents. High CO2 -grown ggt1 plants transferred to air revealed a rapid decrease of An and photosynthetic electron transfer rate while maintaining a high energetic state. Short-term (a night period and 4 h of light) transferred ggt1 leaves accumulated glyoxylate and exhibited low serine contents, while other amino acid levels were not modified. RuBisCO content, activity and activation state were not altered after a short-term transfer while the ATP/ADP ratio was lowered in ggt1 rosettes. However, plant growth and RuBisCO levels were both reduced in ggt1 leaves after a long-term (12 days) acclimation to air from high CO2 when compared to WT plants. The data are discussed with respect to a reduced photorespiratory carbon recycling in the mutants. It is proposed that the low An limits nitrogen-assimilation, this decreases leaf RuBisCO content until plants attain a new homeostatic state that maintains a constant C/N balance and leads to smaller, slower growing plants. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  18. OSMOSE experiment: high minor actinides contents pellets and pins fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Jankowiak, A.; Leorier, C.; Desmouliere, F.; Donnet, L. [Commissariat a l' Energie Atomique, CEA/DEN/VRH/DTEC/SDTC/LEMA, 30207 Bagnols-sur-Ceze cedex (France); Antony, M. [Commissariat a l' Energie Atomique, CEA/DEN/CAD/DER/SPEX/LPE, 13108 St Paul Lez Durance cedex (France); Bernard, D. [Commissariat a l' Energie Atomique, CEA/DEN/ CAD/DER /SPRC/LEPh, 13108 St Paul Lez Durance cedex (France)

    2008-07-01

    The OSMOSE program aims to provide accurate experimental data on integral neutron cross-sections of isotopes (i.e.: Th{sup 232}, U{sup 233}, U{sup 234}, U{sup 235}, U{sup 236}, U{sup 238}, Np{sup 237}, Pu{sup 238}, Pu{sup 239}, Pu{sup 240}, Pu{sup 241}, Pu{sup 242}, Am{sup 241}, Am{sup 243}, Cm{sup 244} and Cm{sup 245}). The study of these nuclides is performed on a large range of neutron spectra corresponding to specific experimental conditions (thermal, epithermal, moderated/fast, and fast spectra). This program will be used to provide guidance to all nuclear data programs in the world. This program has led to an optimized fabrication process for OSMOSE pellets and pins which were fabricated by the LEMA (Actinide based Materials Study Laboratory) in the ATALANTE facility both in glove box and shielded cell. The fabrication process made possible to obtain the required material characteristics including a high density, a good distribution of the isotopes in the uranium oxide matrices. A particular attention was paid to reduce chemical pollution of the samples. The program has been successfully achieved in July 2007 with the fabrication of the last two Cm doped samples. (authors)

  19. Elevation-based upscaling of organic carbon stocks in High-Arctic permafrost terrain

    DEFF Research Database (Denmark)

    Weiss, Niels; Faucherre, Samuel; Lampiris, Nikos

    2017-01-01

    Accurate quantity and distribution estimates of permafrost soil organic carbon (SOC) stocks are needed to project potential feedbacks to climate, following warming. Still, upscaling from local field observations to regional estimates to circumarctic assessments remains a challenge. Here we explore...... elevation-based upscaling techniques for High-Arctic permafrost SOC stocks. We combine two detailed, high-resolution SOC inventories on Spitsbergen (Svalbard) with regional validation data. We find a clear relationship between elevation and SOC content, and use this observed exponential correlation, as well...... as discrete elevation classes, as upscaling models for Spitsbergen. We estimate the total amount of permafrost SOC currently present in soils on Spitsbergen to be 105.36 Tg (0.11 Pg), with a mean SOC content of 2.84 ± 0.74 kg C m−2 (mean ± 95% confidence interval). Excluding glaciers and permanent snowfields...

  20. Allowable carbon emissions for medium-to-high mitigation scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Tachiiri, Kaoru; Hargreaves, Julia C.; Annan, James D.; Kawamiya, Michio [Research Inst. for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokohama, (Japan)], e-mail: tachiiri@jamstec.go.jp; Huntingford, Chris [Centre for Ecology and Hydrology, Wallingford (United Kingdom)

    2013-11-15

    Using an ensemble of simulations with an intermediate complexity climate model and in a probabilistic framework, we estimate future ranges of carbon dioxide (CO{sub 2}) emissions in order to follow three medium-high mitigation concentration pathways: RCP2.6, RCP4.5 and SCP4.5 to 2.6. Uncertainty is first estimated by allowing modelled equilibrium climate sensitivity, aerosol forcing and intrinsic physical and biogeochemical processes to vary within widely accepted ranges. Results are then constrained by comparison against contemporary measurements. For both constrained and unconstrained projections, our calculated allowable emissions are close to the standard (harmonised) emission scenarios associated with these pathways. For RCP4.5, which is the most moderate scenario considered in terms of required emission abatement, then after year 2100 very low net emissions are needed to maintain prescribed year 2100 CO{sub 2} concentrations. As expected, RCP2.6 and SCP4.5 to 2.6 require more strict emission reductions. The implication of this is that direct sequestration of carbon dioxide is likely to be required for RCP4.5 or higher mitigation scenarios, to offset any minimum emissions for society to function (the 'emissions floor'). Despite large uncertainties in the physical and biogeochemical processes, constraints from model-observational comparisons support a high degree of confidence in predicting the allowable emissions consistent with a particular concentration pathway. In contrast the uncertainty in the resulting temperature range remains large. For many parameter sets, and especially for RCP2.6, the land will turn into a carbon source within the twenty first century, but the ocean will remain as a carbon sink. For land carbon storage and our modelling framework, major reductions are seen in northern high latitudes and the Amazon basin even after atmospheric CO{sub 2} is stabilised, while for ocean carbon uptake, the tropical ocean regions will be a

  1. Equation of State of Fe3C and Implications for the Carbon Content of Earth's Core

    Science.gov (United States)

    Davis, A.; Brauser, N.; Thompson, E. C.; Chidester, B.; Greenberg, E.; Prakapenka, V. B.; Campbell, A.

    2017-12-01

    Carbon is a common component in protoplanetary cores, as represented by iron meteorites. Therefore, along with silicon, oxygen, and other light elements, it is likely to be an alloying component with iron in Earth's core. Previous studies of the densities of iron carbides have not reached the combined pressure and temperature conditions relevant to Earth's core. To better understand the geophysical implications of carbon addition to Earth's core, we report P-V-T measurements of Fe3C to pressures and temperatures exceeding 110 GPa and 2500 K, using synchrotron X-ray diffraction in a laser heated diamond anvil cell. Fitting these measurements to an equation of state and assuming 1.5% density change upon melting and a 4000 K core-mantle boundary temperature, we report a value of 6 wt% carbon necessary to match the PREM density in the outer core. This value should be considered an upper bound due to the likely presence of other light elements.

  2. Nanostructured composite TiO{sub 2}/carbon catalysts of high activity for dehydration of n-butanol

    Energy Technology Data Exchange (ETDEWEB)

    Cyganiuk, Aleksandra [Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Torun (Poland); Klimkiewicz, Roman [Institute of Low Temperature and Structure Research PAN, 50-422 Wroclaw (Poland); Bumajdad, Ali [Faculty of Science, Kuwait University, PO Box 5969 Safat, Kuwait 13060 (Kuwait); Ilnicka, Anna [Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Torun (Poland); Lukaszewicz, Jerzy P., E-mail: jerzy_lukaszewicz@o2.pl [Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Torun (Poland)

    2015-08-15

    Highlights: • New biotechnological method for fabrication of composite catalysts. • In situ synthesis of nanosized TiO{sub 2} clusters in the carbon matrix. • High dispersion of TiO{sub 2} in carbon matrix. • High catalytic activity achieved for very low active phase content. • Efficient dehydration of n-butanol to butane-1. - Abstract: A novel method of wood impregnation with titanium ions is presented. Titanium(IV) ions were complexed to peroxo/hydroxo complexes which were obtained by treating a TiCl{sub 4} water solution with H{sub 2}O{sub 2}. The solution of chelated titanium ions was used for the impregnation of living stems of Salix viminalis wood. Saturated stems were carbonized at 600–800 °C, yielding a microporous carbon matrix, in which nanoparticles of TiO{sub 2} were uniformly distributed. A series of composite TiO{sub 2}–carbon catalysts was manufactured and tested in the process of n-butanol conversion to butane-1. The composite catalysts exhibited very high selectivity (ca. 80%) and yield (ca. 30%) despite a low content of titanium (ca. 0.5% atomic). The research proved that the proposed functionalization led to high dispersion of the catalytic phase (TiO{sub 2}), which played a crucial role in the catalyst performance. High dispersion of TiO{sub 2} was achieved due to a natural transport of complexed titanium ions in living plant stems.

  3. Immediate analysis of the oil content of seeds by carbon-13 nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Leal, K.Z.; Costa, V.E.U.; Seidl, P.R.; Campos, M.P.A.; Colnago, L.A.

    1981-01-01

    The carbon 13 nuclear magnetic resonance (CMR) spectra of a series of Brazilian oilseeds was registered. The main constituents of the oils are identified and signals for each carbon atom are assigned. Chemical shifts are estimated for the free fatty acids and compared to those observed from the seeds, with good results. Besides being non-destructive, the RMC method proves to be fast and is useful in the determination of the principal components of the oil fraction of different types of seeds. (Author) [pt

  4. Electrochemical Determination of Caffeine Content in Ethiopian Coffee Samples Using Lignin Modified Glassy Carbon Electrode

    OpenAIRE

    Amare, Meareg; Aklog, Senait

    2017-01-01

    Lignin film was deposited at the surface of glassy carbon electrode potentiostatically. In contrast to the unmodified glassy carbon electrode, an oxidative peak with an improved current and overpotential for caffeine at modified electrode showed catalytic activity of the modifier towards oxidation of caffeine. Linear dependence of peak current on caffeine concentration in the range 6 ? 10?6 to 100 ? 10?6?mol?L?1 with determination coefficient and method detection limit (LoD = 3?s/slope) of 0....

  5. The Effect Of Carbon Concentration On The Retained Austenite Content And The Mechanical Properties Of TRIP Steel Wire Rod Obtained From The Stelmor Controlled Cooling Line

    Directory of Open Access Journals (Sweden)

    Muskalski Z.

    2015-09-01

    Full Text Available The austenite content of the multiphase TRIP-structure steels depends, inter alia, on the carbon concentration and the properly selected parameters of the two-stage heat treatment.

  6. Potassium vapor assisted preparation of highly graphitized hierarchical porous carbon for high rate performance supercapacitors

    Science.gov (United States)

    Liu, Zheng; Zeng, Ying; Tang, Qunli; Hu, Aiping; Xiao, Kuikui; Zhang, Shiying; Deng, Weina; Fan, Binbin; Zhu, Yanfei; Chen, Xiaohua

    2017-09-01

    Ultrahigh graphitized carbon microspheres with rich hierarchical pores (AGHPCM-1) have been successfully synthesized through the one-step activation-carbonization strategy (OACS) with porous sulfonated poly-divinylbenzene as the carbon precursor, iron as the hard template and catalyst, and potassium hydroxide (KOH) as activation agent. Through the XRD, TEM, Raman and BET analysis, AGHPCM-1 shows very high graphitization degree and rich micro-, meso- and macro-pores. More importantly, the mechanism for KOH to improve the graphitization degree of carbon materials in OACS has been illustrated by the thermodynamical theory. The tremendous heat releasing from the reaction between the catalyst precursor of Fe2O3 and potassium vapor plays a key role in the formation of graphitized carbon. It may provide a general direction to prepare highly graphitized porous carbon at a moderate temperature. Integrating the advantages of high graphitization degree and rich hierarchical porous structure, the AGHPCM-1 exhibits an excellent rate performance with a response to up to the high current density of 150 A g-1 and high scan rate of 2000 mV s-1. No obvious capacitance decay can be observed after 10000 charge/discharge cycles even at the high current density of 20 A g-1.

  7. Carbon supported ultrafine gold phosphorus nanoparticles as highly efficient electrocatalyst for alkaline ethanol oxidation reaction

    International Nuclear Information System (INIS)

    Li, Tongfei; Fu, Gengtao; Su, Jiahui; Wang, Yi; Lv, Yinjie; Zou, Xiuyong; Zhu, Xiaoshu; Xu, Lin; Sun, Dongmei; Tang, Yawen

    2017-01-01

    Graphical abstract: We develop a new kind of carbon supported gold-phosphorus (Au-P/C) electrocatalyst by a facile and novel phosphorus reduction method, and demonstrate the Au-P/C is a highly active and stable electrocatalyst for the ethanol oxidation reaction. - Highlights: • Au-P/C catalyst is synthesized by a facile and novel white-phosphorus reduce method. • AuP particles with ultrafine particle-size are uniformly dispersed on carbon support. • Au-P/C catalyst exhibits much higher content of P 0 than reported metal/P catalysts. • Au-P/C catalysts show excellent catalytic properties for ethanol oxidation reaction. - Abstract: Herein, we develop a new kind of carbon supported gold-phosphorus (Au-P/C) electrocatalyst for the alkaline ethanol oxidation reaction (EOR). The Au-P/C catalysts with different Au/P ratio (i.e., AuP/C, Au 3 P 2 /C and Au 4 P 3 /C) can be obtained by a facile and novel hot-reflux method with white phosphorus (P 4 ) as reductant and ethanol as solvent. The crystal structure, composition and particle-size of the Au-P/C catalysts are investigated by X-ray diffraction (XRD), Energy Dispersive Spectrometer (EDS), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), etc. The results demonstrate that Au-P/C catalysts present an alloy phase with the high content of P, ultrafine particle-size and high dispersity on carbon support, which results in excellent electrocatalytic activity and stability towards the EOR compared with that of the free-phosphorus Au/C catalyst. In addition, among the various Au-P/C catalysts with different Au/P ratio, the AuP/C sample exhibits the best electrocatalytic performance in comparison with other Au 3 P 2 /C and Au 4 P 3 /C samples.

  8. Effect of carbonate content on the mechanical behaviour of clay fault-gouges

    Science.gov (United States)

    Bakker, Elisenda; Niemeijer, André; Hangx, Suzanne; Spiers, Chris

    2015-04-01

    Carbon dioxide capture and storage (CCS) in depleted oil and gas reservoirs is considered to be the most promising technology to achieve large-scale reduction in anthropogenic emissions. In order to retain the stored CO2 from the atmosphere for the very long-term, i.e. on timescales of the order of 103-104 years, it is essential to maintain the integrity of the caprock, and more specifically of any faults penetrating the seal. When selecting suitable CO2-storage reservoirs, pre-exisiting faults within the caprock require close attention, as changes in the stress state resulting from CO2-injection may induce fault slip motion which might cause leakage. Little is known about the effect of fluid-rock interactions on the mineral composition, mechanical properties and the integrity and sealing capacity of the caprock. Previous studies on the effect of mineral composition on the frictional properties of fault gouges have shown that friction is controlled by the dominant phase unless there is a frictionally weak, through-going fabric. However, the effect on stability is less clear. Since long-term CO2-exposure might cause chemical reactions, potentially resulting in the dissolution or precipitation of carbonate minerals, a change in mineralogy could affect the mechanical stability of a caprock significantly. Calcite, for example, is known to be prone to micro-seismicity and shows a transition from velocity-strengthening to velocity-weakening behaviour around 100-150°C. Therefore, we investigated the effect of varying clay:carbonate ratios on fault friction behaviour, fault reactivation potential and slip stability, i.e. seismic vs. aseismic behaviour. Three types of simulated fault gouges were used: i) carbonate-free, natural clay-rich caprock samples, consisting of predominantly phyllosilicates (~80%) and quartz ~20%), ii) pure calcite, and iii) mixtures of carbonate-free clay-rich caprock and pure calcite, with predetermined clay:carbonate ratios. For the natural clay

  9. High performance supercapacitor using catalysis free porous carbon nanoparticles

    International Nuclear Information System (INIS)

    Ali, Gomaa A M; Manaf, Shoriya Aruni Bt Abdul; Chong, Kwok Feng; Hegde, Gurumurthy; Kumar, Anuj

    2014-01-01

    Very high supercapacitance values are obtained using catalyst free porous carbon nanoparticles (PCNs). The obtained PCNs have a porous structure with fine particles 35 nm in size. The specific capacitance of PCNs is 343 F g −1 and 309 F g −1 at 5 mV s −1 and 0.06 A g −1 , respectively. PCNs shows a high cyclic stability of about 90% and high columbic efficiency of 95% over 2500 cycles at 1 A g −1 . Impedance spectra show low resistance of PCNs, supporting their suitability for supercapacitor electrode application. (paper)

  10. Negative-ion production on carbon materials in hydrogen plasma : influence of the carbon hybridization state and the hydrogen content on H- yield

    NARCIS (Netherlands)

    Ahmad, A.; Pardanaud, C.; Carrère, M.; Layet, J.M.; Gicquel, A.; Kumar, P.; Eon, D.; Jaoul, C.; Engeln, R.A.H.; Cartry, G.

    2014-01-01

    Highly oriented polycrystalline graphite (HOPG), boron-doped diamond (BDD), nanocrystalline diamond, ultra-nanocrystalline diamond and diamond-like carbon surfaces are exposed to low-pressure hydrogen plasma in a 13.56 MHz plasma reactor. Relative yields of surface-produced H- ions due to

  11. Laser cladding process development for high carbon steel substrates

    CSIR Research Space (South Africa)

    Lengopeng, T

    2014-11-01

    Full Text Available 316L as a butter layer did not lead to the formation of hard brittle chromium carbides even though the chromium content is high enough for the formation of these stable carbides. It was however observed that the use of an AISI 316L butter layer did...

  12. High Gradient Accelerating Structures for Carbon Therapy Linac

    Energy Technology Data Exchange (ETDEWEB)

    Kutsaev, Sergey; Agustsson, R.; Faillace, L.; Goel, A.; Mustapha, B.; Nassiri, A.; Ostroumov, P.; Plastun, A.; Savin, E.

    2016-05-01

    Carbon therapy is the most promising among techniques for cancer treatment, as it has demonstrated significant improvements in clinical efficiency and reduced toxicity profiles in multiple types of cancer through much better localization of dose to the tumor volume. RadiaBeam, in collaboration with Argonne National Laboratory, are developing an ultra-high gradient linear accelerator, Advanced Compact Carbon Ion Linac (ACCIL), for the delivery of ion-beams with end-energies up to 450 MeV/u for 12C6+ ions and 250 MeV for protons. In this paper, we present a thorough comparison of standing and travelling wave designs for high gradient S-Band accelerating structures operating with ions at varying velocities, relative to the speed of light, in the range 0.3-0.7. In this paper we will compare these types of accelerating structures in terms of RF, beam dynamics and thermo-mechanical performance.

  13. Collapse of accreting carbon-oxygen white dwarfs induced by carbon deflagration at high density

    International Nuclear Information System (INIS)

    Nomoto, K.

    1986-01-01

    A critical condition is obtained for which carbon deflagration induces collapse of an accreting C + O white dwarf, not explosion. If the carbon deflagration is initiated at central density as high as 10 10 g cm -3 and if the propagation of the deflagration wave is slower than ∼ 0.15 υ/sub s/ (υ/sub s/ is the sound speed), electron capture behind the burning front induces collapse to form a neutron star. This is the case for both conductive and convective deflagrations. Such a high central density can be reached if the white dwarf is sufficiently massive and cold at the onset of accretion and if the accretion rate is in the appropriate range. Models for Type Ia and Ib supernovae are also discussed. 66 refs., 8 figs

  14. The global distribution of leaf chlorophyll content and seasonal controls on carbon uptake

    Science.gov (United States)

    Croft, H.; Chen, J. M.; Luo, X.; Bartlett, P. A.; Staebler, R. M.; He, L.; Mo, G.; Luo, S.; Simic, A.; Arabian, J.; He, Y.; Zhang, Y.; Beringer, J.; Hutley, L. B.; Noland, T. L.; Arellano, P.; Stahl, C.; Homolová, L.; Bonal, D.; Malenovský, Z.; Yi, Q.; Amiri, R.

    2017-12-01

    Leaf chlorophyll (ChlLeaf) is crucial to biosphere-atmosphere exchanges of carbon and water, and the functioning of terrestrial ecosystems. Improving the accuracy of modelled photosynthetic carbon uptake is a central priority for understanding ecosystem response to a changing climate. A source of uncertainty within gross primary productivity (GPP) estimates is the failure to explicitly consider seasonal controls on leaf photosynthetic potential. Whilst the inclusion of ChlLeafinto carbon models has shown potential to provide a physiological constraint, progress has been hampered by the absence of a spatially-gridded, global chlorophyll product. Here, we present the first spatially-continuous, global view of terrestrial ChlLeaf, at weekly intervals. Satellite-derived ChlLeaf was modelled using a physically-based radiative transfer modelling approach, with a two stage model inversion method. 4-Scale and SAIL canopy models were first used to model leaf-level reflectance from ENIVSAT MERIS 300m satellite data. The PROSPECT leaf model was then used to derive ChlLeaf from the modelled leaf reflectance. This algorithm was validated using measured ChlLeaf data from 248 measurements within 26 field locations, covering six plant functional types (PFTs). Modelled results show very good relationships with measured data, particularly for deciduous broadleaf forests (R2 = 0.67; pmake an important step towards improving the accuracy of global carbon budgets.

  15. Linking organic carbon, water content and nitrous oxide emission in a reclaimed coal mine soil

    Science.gov (United States)

    Manure-based organic amendments can restore soil quality and allow for intensive sustained biomass production on degraded lands. However the large quantities of nitrogen and organic carbon added with such amendments could create soil conditions favorable for nitrous oxide production and emissions. T...

  16. A review of volatile compounds in tektites, and carbon content and isotopic composition of moldavite glass

    Czech Academy of Sciences Publication Activity Database

    Žák, Karel; Skála, Roman; Řanda, Zdeněk; Mizera, Jiří

    2012-01-01

    Roč. 47, č. 6 (2012), s. 1010-1028 ISSN 1086-9379 R&D Projects: GA ČR GA205/09/0991 Institutional research plan: CEZ:AV0Z30130516; CEZ:AV0Z10480505 Keywords : moldavites * geochemistry * ries * carbon stable isotopes * moldavites (Germany) Subject RIV: DD - Geochemistry Impact factor: 2.800, year: 2012

  17. Empirical observations offer improved estimates of forest floor carbon content across in the United States

    Science.gov (United States)

    Perry, C. H.; Domke, G. M.; Walters, B. F.; Smith, J. E.; Woodall, C. W.

    2014-12-01

    The Forest Inventory and Analysis (FIA) program of the United States Forest Service reports official estimates of national forest floor carbon (FFC) stocks and stock change to national and international parties, the US Environmental Protection Agency (USEPA) and the United Nations Framework Convention on Climate Change (UNFCCC), respectively. These estimates of national FFC stocks are derived from plot-level predictions of FFC density. We suspect the models used to predict plot-level FFC density are less than ideal for several reasons: (a) they are based upon local studies that may not reflect FFC dynamics at the national scale, (b) they are relatively insensitive to climate change, and (c) they reduce the natural variability of the data leading to misplaced confidence in the estimates. However, FIA has measured forest floor attributes since 2001 on a systematic 1/16th subset of a nation-wide array of inventory plots (7 800 of 125 000 plots). Here we address the efficacy of replacing plot-level model predictions with empirical observations of FFC density while assessing the impact of imputing FFC density values to the full plot network on national stock estimates. First, using an equivalence testing framework, we found model predictions of FFC density to differ significantly from the observations in all regions and forest types; the mean difference across all plots was 21 percent (1.81 Mg·ha-1). Furthermore, the model predictions were biased towards the lower end of extant FFC density observations, underestimating it while greatly truncating the range relative to the observations. Second, the optimal imputation approach (k-Nearest Neighbor, k-NN) resulted in values that were equivalent to observations of FFC density across a range of simulated missingness and maintained the high variability seen in the observations. We used the k-NN approach to impute FFC density values to the 94 percent of FIA inventory plots without soil measurements. Third, using the imputed

  18. Evaluation of ultra-high-performance-fiber reinforced concrete binder content using the response surface method

    International Nuclear Information System (INIS)

    Aldahdooh, M.A.A.; Muhamad Bunnori, N.; Megat Johari, M.A.

    2013-01-01

    Highlights: • We develop a practical method for adjusting the binder content of UHP-FRC. • We adjust the binder content of UHP-FRC mixtures using RSM. • Increasing the cement content does not contribute to enhance strength. • Increasing the content of cement will increase the flow of UHP-FRC mixtures. - Abstract: One of the major disadvantages in ultra-high-performance-fiber reinforced concrete (UHP-FRC) is its high ordinary Portland cement (OPC) content, which directly translates into an increase in OPC production. More OPC production results in increased emission of greenhouse gases, as well increased electrical energy consumption and concrete price. This study is aimed at adjusting the binder content (OPC and silica fume (SF) contents) of UHP-FRC using the response surface method. The present investigation shows that, for a given water/binder and superplasticizer/OPC, the compressive strength is independent of the binder content, whereas the flow depends on the binder content. Increasing the binder content does not enhance the strength compared with the required design strength because the capillary porosity increases with increasing OPC content; however, the workability increases. The final result is the production of a UHP-FRC with an OPC content of 720.49 kg/m 3 , an SF content of 214.25 kg/m 3 , a compressive strength of 181.41 MPa, a direct tensile strength of 12.49 MPa, a bending tensile strength of 30.31 MPa, and a flow of 167 mm

  19. Pumpkin-Derived Porous Carbon for Supercapacitors with High Performance.

    Science.gov (United States)

    Bai, Suying; Tan, Guangqun; Li, Xiaoqin; Zhao, Qian; Meng, Yan; Wang, Yujue; Zhang, Yongzhi; Xiao, Dan

    2016-06-21

    Pumpkin has been employed for the first time as a renewable, low-cost precursor for the preparation of porous carbon materials with excellent performance. Unlike most other precursors, pumpkin is rich in sugars and starch, and it has advantageous properties for large-scale production. The as-prepared materials adopted a unique morphology that consisted of numerous fused sphere-like carbon grains with a high specific surface area (2968 m(2)  g(-1) ), abundant micro and mesopores, and excellent electrochemical properties. The pumpkin-derived activated carbon (PAC) material not only exhibited a high specific capacitance of 419 F g(-1) , but also showed considerable cycling stability, with 93.6 % retention after 10 000 cycles. Moreover, a symmetrical supercapacitor that was based on PAC showed a high energy density of 22.1 W h kg(-1) in aqueous electrolyte. These superior properties demonstrate that PAC holds great promise for applications in electrochemical energy-storage devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Diffusion barrier coatings for high temperature corrosion resistance of advanced carbon/carbon composites

    International Nuclear Information System (INIS)

    Singh Raman, K.S.

    2000-01-01

    Carbon possesses an excellent combination of mechanical and thermal properties, viz., excellent creep resistance at temperatures up to 2400 deg C in non-oxidizing environment and a low thermal expansion coefficient. These properties make carbon a potential material for very high temperature applications. However, the use of carbon materials at high temperatures is considerably restricted due to their extremely poor oxidation resistance at temperatures above 400 deg C. The obvious choice for improving high temperature oxidation resistance of such materials is a suitable diffusion barrier coating. This paper presents an overview of recent developments in advanced diffusion- and thermal-barrier coatings for ceramic composites, with particular reference to C/C composites. The paper discusses the development of multiphase and multi-component ceramic coatings, and recent investigations on the oxidation resistance of the coated C/C composites. The paper also discusses the cases of innovative engineering solutions for traditional problems with the ceramic coatings, and the scope of intelligent processing in developing coatings for the C/C composites. Copyright (2000) AD-TECH - International Foundation for the Advancement of Technology Ltd

  1. Advances in Predictive Toxicology for Discovery Safety through High Content Screening.

    Science.gov (United States)

    Persson, Mikael; Hornberg, Jorrit J

    2016-12-19

    High content screening enables parallel acquisition of multiple molecular and cellular readouts. In particular the predictive toxicology field has progressed from the advances in high content screening, as more refined end points that report on cellular health can be studied in combination, at the single cell level, and in relatively high throughput. Here, we discuss how high content screening has become an essential tool for Discovery Safety, the discipline that integrates safety and toxicology in the drug discovery process to identify and mitigate safety concerns with the aim to design drug candidates with a superior safety profile. In addition to customized mechanistic assays to evaluate target safety, routine screening assays can be applied to identify risk factors for frequently occurring organ toxicities. We discuss the current state of high content screening assays for hepatotoxicity, cardiotoxicity, neurotoxicity, nephrotoxicity, and genotoxicity, including recent developments and current advances.

  2. Assessment of pre-industrial carbon dioxide content in the atmosphere using hydro-chemical data

    International Nuclear Information System (INIS)

    Heans, K.A.; Liaxin, Y.I.

    2001-01-01

    A hydrochemical method has been developed to calculate concentrations of carbon dioxide (CO 2 ) in the pre-industrial atmosphere and its relationship to climatic change. The following factors affect the Earth's climate: (1) the sun with all its processes, (2) the attraction of the moon that limits the axis of inclination of the Earth, and (3) the cycle of carbon dioxide and the greenhouse effect. An imbalance in the climate system would be a major global disaster that could be detrimental for life on Earth. Recent studies and temperature measurements have shown a trend in which air temperature has increased in the troposphere in the last 100 years, affecting the normal development of natural processes. Various phenomena result from climatic change, or the gradual heating of the Earth. These include the weakening of the glacial layer that covers the Earth's surface, cycles of prolonged slowing in freeze and thaw periods of aquatic surfaces, and increased air temperature in the troposphere which can also causes abnormal fluctuations of temperature in the atmosphere, resulting in heat waves and droughts. Gradual heating of the Earth can also result in rainy periods that produce devastating floods, hurricanes and extreme winds. Changes in water temperature can influence pH levels which affect certain marine species. An increase of 5 degrees C in the global average atmospheric temperature has created changes in 420 physical processes as well as in the behavior of plants and animals. The author stated that the most drastic factor that affects the balance of the Earth's climate is the actions of man interfering with the carbon cycle, as carbon dioxide plays a vital role in the formation of the greenhouse effect. The problem results from an imbalance of the carbon dioxide cycle when CO 2 emissions are increased through the combustion of fossil fuels. It was determined that before the beginning of the Industrial Revolution, carbon dioxide in the atmosphere was 256 ppm

  3. High performance ultracapacitors with carbon nanomaterials and ionic liquids

    Science.gov (United States)

    Lu, Wen; Henry, Kent Douglas

    2012-10-09

    The present invention is directed to the use of carbon nanotubes and/or electrolyte structures in various electrochemical devices, such as ultracapacitors having an ionic liquid electrolyte. The carbon nanotubes are preferably aligned carbon nanotubes. Compared to randomly entangled carbon nanotubes, aligned carbon nanotubes can have better defined pore structures and higher specific surface areas.

  4. Microwave absorbing properties of polyaniline/multi-walled carbon nanotube composites with various polyaniline contents

    International Nuclear Information System (INIS)

    Ting, T.H.; Jau, Y.N.; Yu, R.P.

    2012-01-01

    Polyaniline/multi-walled carbon nanotube (PANI/MWNT) composites were synthesized using in situ polymerization at different aniline/multi-walled carbon nanotube weight ratios (Ani/MWNT = 1/2, 1/1, 2/1 and 3/1) and introduced into an epoxy resin to act as a microwave absorber. The spectroscopic characterization of the process of formation of PANI/MWNT composites were studied using Fourier transform infrared spectroscopy, an ultraviolet-visible spectrophotometer, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and electron spin resonance. The microwave absorbing properties were investigated by measuring complex permittivity, complex permeability and reflection loss in the 2-18 and 18-40 GHz microwave frequency range, using the free space method. The results showed that the addition of PANI was useful for achieving a large absorption over a wide frequency range, especially for higher frequency values.

  5. Hydrogen production from high-moisture content biomass in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Antal, M.J. Jr.; Adschiri, T.; Ekbom, T. [Univ. of Hawaii, Honolulu, HI (United States)] [and others

    1996-10-01

    Most hydrogen is produced by steam reforming methane at elevated pressures. The goal of this research is to develop commercial processes for the catalytic steam reforming of biomass and other organic wastes at high pressures. This approach avoids the high cost of gas compression and takes advantage of the unique properties of water at high pressures. Prior to this year the authors reported the ability of carbon to catalyze the decomposition of biomass and related model compounds in supercritical water. The product gas consists of hydrogen, carbon dioxide, carbon monoxide, methane, and traces of higher hydrocarbons. During the past year the authors have: (a) developed a method to extend the catalyst life, (b) begun studies of the role of the shift reaction, (c) completed studies of carbon dioxide absorption from the product effluent by high pressure water, (d) measured the rate of carbon catalyst gasification in supercritical water, (e) discovered the pumpability of oil-biomass slurries, and (f) completed the design and begun fabrication of a flow reactor that will steam reform whole biomass feedstocks (i.e. sewage sludge) and produce a hydrogen rich synthesis gas at very high pressure (>22 MPa).

  6. Friction stir processing on high carbon steel U12

    Energy Technology Data Exchange (ETDEWEB)

    Tarasov, S. Yu., E-mail: tsy@ispms.ru; Rubtsov, V. E., E-mail: rvy@ispms.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Melnikov, A. G., E-mail: melnikov-ag@tpu.ru [National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2015-10-27

    Friction stir processing (FSP) of high carbon steel (U12) samples has been carried out using a milling machine and tools made of cemented tungsten carbide. The FSP tool has been made in the shape of 5×5×1.5 mm. The microstructural characterization of obtained stir zone and heat affected zone has been carried out. Microhardness at the level of 700 MPa has been obtained in the stir zone with microstructure consisting of large grains and cementitte network. This high-level of microhardness is explained by bainitic reaction developing from decarburization of austenitic grains during cementite network formation.

  7. Austria's CO2 responsibility and the carbon content of its international trade

    International Nuclear Information System (INIS)

    Munoz, Pablo; Steininger, Karl W.

    2010-01-01

    Seeking to limit global warming to 2 C puts narrow restrictions on the remaining carbon budget. While the prevalent accounting framework for carbon emissions is production based (Production-Based Principle, PBP), we here quantify the CO 2 emissions on the basis of the Consumption-Based Principle (CBP) for Austria. At a methodological level, a Multi-Regional Input-Output model with full linkages is used to account for Austria's CO 2 responsibility on a global scale. Estimates are carried out for the years 1997 and 2004. Results show that during 1997 CO 2 responsibility based on CBP were 36% larger than those based on PBP. This relation has increased through time. The CBP indicator of 2004 was 44% larger than the PBP. In terms of carbon emission location, for each Euro spent on Austrian final demand in 2004, it is estimated that two-thirds of the CO 2 emissions occur outside Austrian borders. Regarding the origin of the emissions embodied in imports, it is estimated that about one-fourth originated in non-Annex I countries in 1997. This proportion increased to one-third by 2004. Due to this divergence between CBP and PBP indicators, there is a need to re-think current accounting bases in order to properly assign CO 2 responsibilities. (author)

  8. Cytotoxic Deoxypodophyllotoxin Can Be Extracted in High Purity from Anthriscus sylvestris Roots by Supercritical Carbon Dioxide.

    Science.gov (United States)

    Seegers, Christel L C; Tepper, Pieter G; Setroikromo, Rita; Quax, Wim J

    2018-05-01

    Deoxypodophyllotoxin is present in the roots of Anthriscus sylvestris . This compound is cytotoxic on its own, but it can also be converted into podophyllotoxin, which is in high demand as a precursor for the important anticancer drugs etoposide and teniposide. In this study, deoxypodophyllotoxin is extracted from A. sylvestris roots by supercritical carbon dioxide extraction. The process is simple and scalable. The supercritical carbon dioxide method extracts 75 - 80% of the total deoxypodophyllotoxin content, which is comparable to a single extraction by traditional Soxhlet. However, less polar components are extracted. The activity of the supercritical carbon dioxide extract containing deoxypodophyllotoxin was assessed by demonstrating that the extract arrests A549 and HeLa cells in the G 2 /M phase of the cell cycle. We conclude that biologically active deoxypodophyllotoxin can be extracted from A. sylvestris by supercritical carbon dioxide extraction. The method is solvent free and more sustainable compared to traditional methods. Georg Thieme Verlag KG Stuttgart · New York.

  9. High-Performance Field Emission from a Carbonized Cork.

    Science.gov (United States)

    Lee, Jeong Seok; Lee, Hak Jun; Yoo, Jae Man; Kim, Taewoo; Kim, Yong Hyup

    2017-12-20

    To broaden the range of application of electron beams, low-power field emitters are needed that are miniature and light. Here, we introduce carbonized cork as a material for field emitters. The light natural cork becomes a graphitic honeycomb upon carbonization, with the honeycomb cell walls 100-200 nm thick and the aspect ratio larger than 100, providing an ideal structure for the field electron emission. Compared to nanocarbon field emitters, the cork emitter produces a high current density and long-term stability with a low turn-on field. The nature of the cork material makes it quite simple to fabricate the emitter. Furthermore, any desired shape of the emitter tailored for the final application can easily be prepared for point, line, or planar emission.

  10. High performance all-carbon composite transparent electrodes containing uniform carbon nanotube networks

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Hyung Duk; Kwak, Jinsung; Kim, Se-Yang [School of Materials Science and Engineering & Low-Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 (Korea, Republic of); Seo, Han; Bang, In Cheol; Kim, Sung Youb [School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 (Korea, Republic of); Kang, Seoktae [Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141 (Korea, Republic of); Kwon, Soon-Yong, E-mail: sykwon@unist.ac.kr [School of Materials Science and Engineering & Low-Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 (Korea, Republic of); School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 (Korea, Republic of)

    2016-08-05

    Indium tin oxide-free, flexible transparent electrodes (TEs) are crucial for the future commercialization of flexible and wearable electronics. While carbon-based TEs containing carbon nanotube (CNT) networks show promise, they usually exhibit poor dispersion properties, limiting their performance and practicality. In this study, we report a highly efficient and bending durable all-carbon composite TE (ac-TE) that employs uniform CNT networks on a monolayer graphene/polyethylene terephthalate (PET) substrate via a simple air spray deposition method. The air-sprayed CNT/graphene assembly was free-standing on solution, making a polymer-free transfer of carbon composites to target substrates possible. The excellent performance of the ac-TEs was attributed to the uniformly networked CNTs on the polycrystalline graphene with a well-controlled density, effectively bridging the line defects and filling the tears/voids or folds necessarily existing in the as-processed graphene. The sheet resistance of the ac-TEs was increased only 6% from its original value at a bending radius of 2.7 mm, while that of the pristine graphene/PET assembly increased 237%. Mechanical bending of the ac-TEs worsened the electrical performance by only ∼1.7% after 2000 bending cycles at a bending radius of 2.5 mm. Degradation of the performance by the bending was the result of line defects formation in the graphene, demonstrating the potential of the uniform CNT networks to achieve more efficient and flexible carbon-based TEs. Furthermore, the chemically-doped ac-TEs showed commercially suitable electronic and optical properties with much enhanced thermal stability, closer to practical TEs in flexible devices. - Highlights: • Highly efficient and bending durable all-carbon composite transparent electrodes (TEs) are designed. • The performance was strongly dependent on morphology of CNT networks on graphene. • The mechanism relies on the defect reductions in graphene by uniform CNT coating

  11. High performance all-carbon composite transparent electrodes containing uniform carbon nanotube networks

    International Nuclear Information System (INIS)

    Yun, Hyung Duk; Kwak, Jinsung; Kim, Se-Yang; Seo, Han; Bang, In Cheol; Kim, Sung Youb; Kang, Seoktae; Kwon, Soon-Yong

    2016-01-01

    Indium tin oxide-free, flexible transparent electrodes (TEs) are crucial for the future commercialization of flexible and wearable electronics. While carbon-based TEs containing carbon nanotube (CNT) networks show promise, they usually exhibit poor dispersion properties, limiting their performance and practicality. In this study, we report a highly efficient and bending durable all-carbon composite TE (ac-TE) that employs uniform CNT networks on a monolayer graphene/polyethylene terephthalate (PET) substrate via a simple air spray deposition method. The air-sprayed CNT/graphene assembly was free-standing on solution, making a polymer-free transfer of carbon composites to target substrates possible. The excellent performance of the ac-TEs was attributed to the uniformly networked CNTs on the polycrystalline graphene with a well-controlled density, effectively bridging the line defects and filling the tears/voids or folds necessarily existing in the as-processed graphene. The sheet resistance of the ac-TEs was increased only 6% from its original value at a bending radius of 2.7 mm, while that of the pristine graphene/PET assembly increased 237%. Mechanical bending of the ac-TEs worsened the electrical performance by only ∼1.7% after 2000 bending cycles at a bending radius of 2.5 mm. Degradation of the performance by the bending was the result of line defects formation in the graphene, demonstrating the potential of the uniform CNT networks to achieve more efficient and flexible carbon-based TEs. Furthermore, the chemically-doped ac-TEs showed commercially suitable electronic and optical properties with much enhanced thermal stability, closer to practical TEs in flexible devices. - Highlights: • Highly efficient and bending durable all-carbon composite transparent electrodes (TEs) are designed. • The performance was strongly dependent on morphology of CNT networks on graphene. • The mechanism relies on the defect reductions in graphene by uniform CNT coating

  12. A high-performance mesoporous carbon supported nitrogen-doped carbon electrocatalyst for oxygen reduction reaction

    Science.gov (United States)

    Xu, Jingjing; Lu, Shiyao; Chen, Xu; Wang, Jianan; Zhang, Bo; Zhang, Xinyu; Xiao, Chunhui; Ding, Shujiang

    2017-12-01

    Investigating low-cost and highly active electrocatalysts for oxygen reduction reactions (ORR) is of crucial importance for energy conversion and storage devices. Herein, we design and prepare mesoporous carbon supported nitrogen-doped carbon by pyrolysis of polyaniline coated on CMK-3. This electrocatalyst exhibits excellent performance towards ORR in alkaline media. The optimized nitrogen-doped mesoporous electrocatalyst show an onset potential (E onset) of 0.95 V (versus reversible hydrogen electrode (RHE)) and half-wave potential (E 1/2) of 0.83 V (versus RHE) in 0.1 M KOH. Furthermore, the as-prepared catalyst presents superior durability and methanol tolerance compared to commercial Pt/C indicating its potential applications in fuel cells and metal-air batteries.

  13. International Student Carbon Footprint Challenge--Social Media as a Content and Language Integrated Learning Environment

    Science.gov (United States)

    Fauville, Géraldine; Lantz-Andersson, Annika; Säljö, Roger

    2012-01-01

    Environmental education (EE) is now clearly specified in educational standards in many parts of the world, and at the same time the view of language learning is moving towards a content and language integrated learning (CLIL) strategy, to make English lessons more relevant and attractive for students (Eurydice, 2006). In this respect,…

  14. Voltammetric determination of polyphenolic content in pomegranate juice using a poly(gallic acid/multiwalled carbon nanotube modified electrode

    Directory of Open Access Journals (Sweden)

    Refat Abdel-Hamid

    2016-07-01

    Full Text Available A simple and sensitive poly(gallic acid/multiwalled carbon nanotube modified glassy carbon electrode (PGA/MWCNT/GCE electrochemical sensor was prepared for direct determination of the total phenolic content (TPC as gallic acid equivalent. The GCE working electrode was electrochemically modified and characterized using scanning electron microscope (SEM, cyclic voltammetry (CV, chronoamperometry and chronocoulometry. It was found that gallic acid (GA exhibits a superior electrochemical response on the PGA/MWCNT/GCE sensor in comparison with bare GCE. The results reveal that a PGA/MWCNT/GCE sensor can remarkably enhance the electro-oxidation signal of GA as well as shift the peak potentials towards less positive potential values. The dependence of peak current on accumulation potential, accumulation time and pH were investigated by square-wave voltammetry (SWV to optimize the experimental conditions for the determination of GA. Using the optimized conditions, the sensor responded linearly to a GA concentration throughout the range of 4.97 × 10−6 to 3.38 × 10−5 M with a detection limit of 3.22 × 10−6 M (S/N = 3. The fabricated sensor shows good selectivity, stability, repeatability and (101% recovery. The sensor was successfully utilized for the determination of total phenolic content in fresh pomegranate juice without interference of ascorbic acid, fructose, potassium nitrate and barbituric acid. The obtained data were compared with the standard Folin–Ciocalteu spectrophotometric results.

  15. Carbon nanotube transistor based high-frequency electronics

    Science.gov (United States)

    Schroter, Michael

    At the nanoscale carbon nanotubes (CNTs) have higher carrier mobility and carrier velocity than most incumbent semiconductors. Thus CNT based field-effect transistors (FETs) are being considered as strong candidates for replacing existing MOSFETs in digital applications. In addition, the predicted high intrinsic transit frequency and the more recent finding of ways to achieve highly linear transfer characteristics have inspired investigations on analog high-frequency (HF) applications. High linearity is extremely valuable for an energy efficient usage of the frequency spectrum, particularly in mobile communications. Compared to digital applications, the much more relaxed constraints for CNT placement and lithography combined with already achieved operating frequencies of at least 10 GHz for fabricated devices make an early entry in the low GHz HF market more feasible than in large-scale digital circuits. Such a market entry would be extremely beneficial for funding the development of production CNTFET based process technology. This talk will provide an overview on the present status and feasibility of HF CNTFET technology will be given from an engineering point of view, including device modeling, experimental results, and existing roadblocks. Carbon nanotube transistor based high-frequency electronics.

  16. The influence of compound admixtures on the properties of high-content slag cement

    Energy Technology Data Exchange (ETDEWEB)

    Dongxu, L.; Xuequan, W.; Jinlin, S.; Yujiang, W.

    2000-01-01

    Based on the activation theory of alkali and sulfate, the influence of compound admixtures on the properties of high-content slag cement was studied by testing the strength, pore structure, hydrates, and microstructure, Test results show that compound admixtures can obviously improve the properties of high-content slag cement. The emphasis of the present research is two-fold: substituting gypsum with anhydrite and calcining gypsum. These both can improve early and later performance.

  17. The technology of uranium extraction from the brine with high chlorine-ion content

    International Nuclear Information System (INIS)

    Khakimov, N.; Nazarov, Kh.M.; Mirsaidov, I.U.; Negmatov, Sh.I.; Barotov, B.B.

    2010-01-01

    Present article is devoted to technology of uranium extraction from the brine with high chlorine-ion content. The research results on uranium extraction from the brine of Sasik-Kul Lake by means of sorption method were considered. The chemical composition of salt was determined. The process of uranium sorption was described and analyzed. The technology of uranium extraction from the brine with high chlorine-ion content was proposed.

  18. Heterogeneous carbonaceous matter in sedimentary rock lithocomponents causes significant trichloroethylene (TCE) sorption in a low organic carbon content aquifer/aquitard system.

    Science.gov (United States)

    Choung, Sungwook; Zimmerman, Lisa R; Allen-King, Richelle M; Ligouis, Bertrand; Feenstra, Stanley

    2014-10-15

    This study evaluated the effects of heterogeneous thermally altered carbonaceous matter (CM) on trichloroethylene (TCE) sorption for a low fraction organic carbon content (foc) alluvial sedimentary aquifer and aquitard system (foc=0.046-0.105%). The equilibrium TCE sorption isotherms were highly nonlinear with Freundlich exponents of 0.46-0.58. Kerogen+black carbon was the dominant CM fraction extracted from the sediments and accounted for >60% and 99% of the total in the sands and silt, respectively. Organic petrological examination determined that the kerogen included abundant amorphous organic matter (bituminite), likely of marine origin. The dark calcareous siltstone exhibited the greatest TCE sorption among aquifer lithocomponents and accounted for most sorption in the aquifer. The results suggest that the source of the thermally altered CM, which causes nonlinear sorption, was derived from parent Paleozoic marine carbonate rocks that outcrop throughout much of New York State. A synthetic aquifer-aquitard unit system (10% aquitard) was used to illustrate the effect of the observed nonlinear sorption on mass storage potential at equilibrium. The calculation showed that >80% of TCE mass contained in the aquifer was sorbed on the aquifer sediment at aqueous concentration TCE groundwater plume in the aquifer studied. It is implied that sorption may similarly contribute to TCE persistence in other glacial alluvial aquifers with similar geologic characteristics, i.e., comprised of sedimentary rock lithocomponents that contain thermally altered CM. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Photometric determination of niobium in materials with high content of phosphorus

    International Nuclear Information System (INIS)

    Navrotskaya, V.A.; Aleksandrova, E.I.; Kletenik, Yu.B.

    1982-01-01

    To determine niobium in various samples of niobium concentrates with a high phosphorus content, a photometric method with pyridylazoresorcinol (PAR) is used. It is shown that all the elements indicated (Fe, Si, Ti, Al, Ca) including phosphorus do not interfere with the niobium determination with the use of PAR. The method has been tried on artificial samples with different content of the base components. Variation coefficient constitutes 4.5%. No systematic errors, due to a high content of any concomitant element, are detected. The determination threshold is 10 - 2 %

  20. Ash content, carbon and C/N ratio in paricá in function of NPK fertilization

    Directory of Open Access Journals (Sweden)

    CRISTIANE R. VIEIRA

    2018-02-01

    Full Text Available ABSTRACT Fertilization in areas of forest plantations is needed to supplement plants´ nutritional needs until harvest. An experiment was performed to check the influence of fertilization on levels of ash, carbon and C/N relation in Schizolobium amazonicum. Soil liming was performed and fertilization occurred after 15 days of incubation. S. amazonicum seedlings were produced and submitted to fertilization with N, P and K: N = 0, 40, 80 and 120 kg ha-1; P2O5 = 0, 50, 100 and 200 kg ha-1; K2O = 0, 50, 100 and 200 kg ha-1. The plants were measured after 180 days. The seedlings of 20 treatments with the highest increase in height and diameter were transplanted to the field. Soil was fertilized and limestone was spread; seedlings were distributed into randomized blocks, with six replications. After 12 months, the plants were removed to determine ash, organic carbon, C/N relation contents. The ashes were submitted to digestion to determine nutrient concentrations. Fertilization influenced the levels of ash and organic carbon and C/N relation in S. amazonicum. Results indicate that the species has a potential for energy production.

  1. Ash content, carbon and C/N ratio in paricá in function of NPK fertilization.

    Science.gov (United States)

    Vieira, Cristiane R; Weber, Oscarlina L S; Scaramuzza, José Fernando

    2018-01-01

    Fertilization in areas of forest plantations is needed to supplement plants´ nutritional needs until harvest. An experiment was performed to check the influence of fertilization on levels of ash, carbon and C/N relation in Schizolobium amazonicum. Soil liming was performed and fertilization occurred after 15 days of incubation. S. amazonicum seedlings were produced and submitted to fertilization with N, P and K: N = 0, 40, 80 and 120 kg ha-1; P2O5 = 0, 50, 100 and 200 kg ha-1; K2O = 0, 50, 100 and 200 kg ha-1. The plants were measured after 180 days. The seedlings of 20 treatments with the highest increase in height and diameter were transplanted to the field. Soil was fertilized and limestone was spread; seedlings were distributed into randomized blocks, with six replications. After 12 months, the plants were removed to determine ash, organic carbon, C/N relation contents. The ashes were submitted to digestion to determine nutrient concentrations. Fertilization influenced the levels of ash and organic carbon and C/N relation in S. amazonicum. Results indicate that the species has a potential for energy production.

  2. In Situ Biodiesel Production from Fast-Growing and High Oil Content Chlorella pyrenoidosa in Rice Straw Hydrolysate

    Science.gov (United States)

    Li, Penglin; Miao, Xiaoling; Li, Rongxiu; Zhong, Jianjiang

    2011-01-01

    Rice straw hydrolysate was used as lignocellulose-based carbon source for Chlorella pyrenoidosa cultivation and the feasibility of in situ biodiesel production was investigated. 13.7 g/L sugar was obtained by enzymatic hydrolyzation of rice straw. Chlorella pyrenoidosa showed a rapid growth in the rice straw hydrolysate medium, the maximum biomass concentration of 2.83 g/L was obtained in only 48 hours. The lipid content of the cells reached as high as 56.3%. In situ transesterification was performed for biodiesel production. The optimized condition was 1 g algal powder, 6 mL n-hexane, and 4 mL methanol with 0.5 M sulfuric acid at the temperature of 90°C in 2-hour reaction time, under which over 99% methyl ester content and about 95% biodiesel yield were obtained. The results suggested that the method has great potential in the production of biofuels with lignocellulose as an alternative carbon source for microalgae cultivation. PMID:21318171

  3. High Altitude Emissions of Black Carbon Aerosols: Potential Climate Implications

    Science.gov (United States)

    Satheesh, S. K.

    2017-12-01

    Synthesizing a series of ground-based and airborne measurements of aerosols over the Indian region during summer and pre-monsoon seasons have revealed the persistence of elevated absorbing aerosol layers over most of the Indian region; more than 50% of which located above clouds. Subsequent, in situ measurements of black carbon (BC) using high-altitude balloons, showed surprising layers with high concentrations in the middle and upper troposphere even at an altitude of 8 to 10 kms. Simultaneous measurements of the vertical thermal structure have shown localized warming due to BC absorption leading to large reduction in lapse rate and sharp temperature inversion, which in turn increases the atmospheric stability. This aerosol-induced stable layer is conducive for maintaining the black carbon layer longer at that level, leading thereby to further solar absorption and subsequently triggering dry convection. These observations support the `solar escalator' concept through which absorption-warming-convection cycles lead to self-lifting of BC to upper troposphere or even to lower stratosphere under favorable conditions in a matter of a few days. Employing an on-line regional chemistry transport model (WRF-Chem), incorporating aircraft emissions, it is shown that emissions from high-flying aircrafts as the most likely source of these elevated black carbon layers. These in-situ injected particles, produce significant warming of the thin air in those heights and lift these layers to even upper tropospheric/lower stratospheric heights, aided by the strong monsoonal convection occurring over the region, which are known to overshoot the tropical tropopause leading to injection of tropospheric air mass (along with its constituent aerosols) into the stratosphere, especially during monsoon season when the tropical tropopause layer is known to be thinnest. These simulations are further supported by the CALIPSO space-borne LIDAR derived extinction coefficient profiles. Based on

  4. Bonding Characteristics of Macrosynthetic Fiber in Latex-Modified Fiber-Reinforced Cement Composites as a Function of Carbon Nanotube Content

    Directory of Open Access Journals (Sweden)

    Ji-Hong Jean

    2016-01-01

    Full Text Available The effect of carbon nanotube content (0, 0.5, 1.0, 1.5, and 2.0% of the cement weight on the bonding properties of macrosynthetic fiber in latex-modified hybrid fiber cement-based composites (LMHFRCCs was evaluated. The slump value, compressive strength, and bonding strength were measured for each LMHFRCC. As the carbon nanotube content increased to 1.5%, the bonding properties of the macrosynthetic fiber improved. However, the bonding performance deteriorated at a carbon nanotube content of 2.0%. A decrease in the fluidity of the mix negatively affected the dispersion of the nanotubes in the LMHFRCCs. The addition of carbon nanotubes also affected the relative bonding strength independently of the improvement in compressive strength. Microscopic analysis of the macrosynthetic fiber surfaces was used to understand changes in the bonding behavior.

  5. Study of the flux effect nature for VVER-1000 RPV welds with high nickel content

    Energy Technology Data Exchange (ETDEWEB)

    Kuleshova, E.A., E-mail: evgenia-orm@yandex.ru [National Research Center “Kurchatov Institute”, Kurchatov Sq.1, 123182, Moscow (Russian Federation); National Research Nuclear University, “MEPhI” (Moscow Engineering Physics Institute), Kashirskoe Highway 31, 115409, Moscow (Russian Federation); Gurovich, B.A.; Lavrukhina, Z.V.; Maltsev, D.A.; Fedotova, S.V.; Frolov, A.S.; Zhuchkov, G.M. [National Research Center “Kurchatov Institute”, Kurchatov Sq.1, 123182, Moscow (Russian Federation)

    2017-01-15

    This work extends the research of the basic regularities of segregation processes in the grain boundaries (GB) of VVER-1000 reactor pressure vessel (RPV) steels. The paper considers the influence of irradiation with different fast neutron fluxes on the structure, yield strength and ductile-to-brittle transition temperature (T{sub K}) changes as well as on changes of the share of brittle intergranular fracture and development of segregation processes in the VVER-1000 RPV weld metal (WM). The obtained experimental results allow to separate the contribution of the hardening and non-hardening mechanisms to mechanical properties degradation of material irradiated at the operating temperature. It is shown that the difference in T{sub K} shift in WM irradiated to the same fluence with different fast neutron fluxes is mainly due to the difference in the GB accumulation kinetics of impurities and only to a small extent due to the material hardening. Phosphorus bulk diffusion coefficients were evaluated for the temperature exposure, accelerated irradiation and irradiation within surveillance specimens (SS) using a kinetic model of phosphorus GB accumulation in low-alloyed low-carbon steels under the influence of operational factors. The correlation between the GB segregation level of phosphorus and nickel, and the T{sub K} shift - in WM SS was obtained experimentally and indicates the non-hardening mechanism contribution to the total radiation embrittlement of VVER-1000 RPV steels throughout its extended lifetime. - Highlights: • Structural elements in high Ni welds are studied at different irradiation fluxes. • AES study demonstrated different P GB kinetics at different irradiation fluxes. • Hardening and non-hardening mechanism contributions to the flux effect are assessed. • Correlation between ΔT{sub K} and P and Ni GB content is shown for VVER-1000 RPV welds.

  6. Carbon, chromium and molybdenum contents; Teores de carbono, cromo e molibdenio

    Energy Technology Data Exchange (ETDEWEB)

    Sinatora, A; Goldenstein, H; Mei, P R; Albertin, E; Fuoco, R; Mariotto, C L

    1993-12-31

    This work describes solidification experiments on white cast iron, with 15 and 20% of chromium, 2.3, 3.0 and 3.6 % of carbon and 0.0, 1.5 and 2.5 % of molybdenum in test de samples with 30 mm diameter. Measurements were performed on the austenite and eutectic formation arrests, the number of the eutectic carbide particles relative to the total and the eutectic volumes, and the volume fraction of the primary austenite 9 figs., 3 tabs.

  7. Carbon, chromium and molybdenum contents; Teores de carbono, cromo e molibdenio

    Energy Technology Data Exchange (ETDEWEB)

    Sinatora, A; Goldenstein, H.; Mei, P.R.; Albertin, E.; Fuoco, R.; Mariotto, C.L

    1992-12-31

    This work describes solidification experiments on white cast iron, with 15 and 20% of chromium, 2.3, 3.0 and 3.6 % of carbon and 0.0, 1.5 and 2.5 % of molybdenum in test de samples with 30 mm diameter. Measurements were performed on the austenite and eutectic formation arrests, the number of the eutectic carbide particles relative to the total and the eutectic volumes, and the volume fraction of the primary austenite 9 figs., 3 tabs.

  8. Highly stable carbon-doped Cu films on barrierless Si

    International Nuclear Information System (INIS)

    Zhang, X.Y.; Li, X.N.; Nie, L.F.; Chu, J.P.; Wang, Q.; Lin, C.H.; Dong, C.

    2011-01-01

    Electrical resistivities and thermal stabilities of carbon-doped Cu films on silicon have been investigated. The films were prepared by magnetron sputtering using a Cu-C alloy target. After annealing at 400 deg. C for 1 h, the resistivity maintains a low level at 2.7 μΩ-cm and no Cu-Si reaction is detected in the film by X-ray diffraction (XRD) and transmission electron microscopy (TEM) observations. According to the secondary ion mass spectroscopy (SIMS) results, carbon is enriched near the interfacial region of Cu(C)/Si, and is considered responsible for the growth of an amorphous Cu(C)/Si interlayer that inhibits the Cu-Si inter-diffusion. Fine Cu grains, less than 100 nm, were present in the Cu(C) films after long-term and high-temperature annealings. The effect of C shows a combination of forming a self-passivated interface barrier layer and maintaining a fine-grained structure of Cu. A low current leakage measured on this Cu(C) film also provides further evidence for the carbon-induced diffusion barrier interlayer performance.

  9. Corrosion resistance properties of enamels with high B2O3-P2O5 content to molten aluminum

    International Nuclear Information System (INIS)

    Zhou, M.; Li, K.; Shu, D.; Sun, B.D.; Wang, J.

    2003-01-01

    Anticorrosive properties of borophosphate and boron-free enamels to molten aluminum were investigated using SEM and electron probe. Carbonates of alkali metal and alkaline earth metal were added in an appropriate weight ratio to achieve desired melting temperature of the enamels. SEM examination on the solidified interface between the enamels and aluminum alloy show that the enamels can spread slightly on aluminum alloy. For anticorrosive sample of borophosphate enamel, phosphorus was not detected by electron probe at the side of aluminum alloy near the interface, but silicon was detected in the silica-free enamels side. For the sample of boron-free enamels, however, phosphorus was found at the side of aluminum alloy near the interface. It was revealed that the enamels with high B 2 O 3 -P 2 O 5 content have high corrosion resistance to molten aluminum

  10. High oleic acid content materials of rapeseed (Brassica napus) produced by radiation breeding

    International Nuclear Information System (INIS)

    Guan Chunyun; Liu Chunlin; Chen Sheyuan

    2006-01-01

    High oleic acid content rapeseed breeding has great significance, because high oleic acid oil is a healthy and nutritious oil, which is of a long shelflife and also propitious to producing biodiesel fuel. The high oleic acid content breeding materials of rapeseed (B. napus) were obtained by 80-100 kR ~(60)Co gamma ray ionizing radiation treatment of dry seeds and continuous selection. The results showed that the oleic acid contents of M (2), M (3) and M (4) progenies increased by different grades. Moreover, the oleic acid content of M (5) progeny increased greatly. The oleic acid contents were higher than 70% in the most of the plants and the highest one reached 93.5 %. The base G was transited by base A in fad (2) gene at the 270 site of high oleic acid mutation (M(6) 04-855). The location is at the beta folding area and conservative area of this protein. Base mutation at sites 1 044 and 1 062 also led to produce a stop condon. These changes in structure led to loss the function of fad (2). According to molecular mechanism of gene mutation, no matter what transvertion or transition happens, several replications are needed. That is to say several generations are needed. That was also the reason why high oleic acid content mutation occurred in later generations

  11. The primary results for the mixed carbon material used for high flux steady-state tokamak operation in China

    International Nuclear Information System (INIS)

    Guo, Q.G.; Li, J.G.; Zhai, G.T.; Liu, L.; Song, J.R.; Zhang, L.F.; He, Y.X.; Chen, J.L.

    2001-01-01

    Several types of carbon mixed materials have been developed in China to be used for high flux steady-state tokamak operation. Performance evaluation of these materials is necessary to determine their applicability as PFCs for high flux steady state. This paper describes the primary results of carbon mixed materials and the effects of dopants on properties are primarily discussed. Test results reveal that bulk boronized graphite has excellent physical and mechanical properties while their thermal conductivity is no more than 73 W/m K due to the formation of a uniform boron-carbon solid solution. In case of multi-element doped graphite, titanium dopant or a decreased boron content is favorable to enhance thermal conductivity. A kind of doped graphite has been developed with thermal conductivity as high as 278 W/m K by optimizing the compositions. Correlations among compositions, microstructure and properties of such doped graphite are discussed

  12. Nitrogen and phosphorus co-doped carbon hollow spheres derived from polypyrrole for high-performance supercapacitor electrodes

    Science.gov (United States)

    Lv, Bingjie; Li, Peipei; Liu, Yan; Lin, Shanshan; Gao, Bifen; Lin, Bizhou

    2018-04-01

    Nitrogen and phosphorus co-doped carbon hollow spheres (NPCHSs) have been prepared by a carbonization and subsequent chemical activation route using dehydrated polypyrrole hollow spheres as the precursor and KOH as the activating agent. NPCHSs are interconnected into a unique 3D porous network, which endows the as-prepared carbon to exhibit a large specific surface area of 1155 m2 g-1 and a high specific capacitance of 232 F g-1 at a current density of 1 A g-1. The as-obtained NPCHSs present a high-level heteroatom doping with N, O and P contents of 11.4, 6.7 and 3.5 wt%, respectively. The capacitance of NPCHSs has been retained at 89.1% after 5000 charge-discharge cycles at a relatively high current density of 5 A g-1. Such excellent performance suggests that NPCHSs are attractive electrode candidates for electrical double layer capacitors.

  13. HTGR fuel rods: carbon-carbon composites designed for high weight and low strength

    International Nuclear Information System (INIS)

    Bullock, R.E.

    1977-01-01

    The evolution of the process for fabricating fuel rods for the high-temperature gas-cooled reactor (HTGR) by injection and carbonization of a thermoplastic matrix that bonds close-packed beds of pyrocarbon-coated fuel particles together is reviewed for the fresh-fuel cycle, and a variant process involving a thermosetting matrix that would allow free-standing carbonization of refabricated fuel is discussed. Previous attempts to fabricate such injection-bonded fuel rods from undiluted thermosetting binders filled with powdered graphite were unsuccessful, because of damage to coatings on fuel particles that resulted from strong particle-to-matrix bonding in conjunction with large matrix shrinkage on carbonization and subsequent irradiation. These problems have now been overcome through the use of a diluted thermosetting matrix with a low-char-yield additive (fugitive), which produces a more porous char similar to that from the pitch-based thermoplastic used in fabrication of fresh fuel. A 1-to-1 dilution of resin with fugitive produced the optimum binder for injection and carbonization, where the fired matrix in such rods contained about 20 wt% binder char and 80 wt% powdered graphite. Thermosetting fuel rods diluted with various amounts of fugitive to give binder chars that range from 12 to 48 wt% of the fired matrix have been subjected to irradiation screening tests, and rods with no more than 32 wt% binder char appear to perform about as well under irradiation as do pitch-based rods. However, particle damage does begin to occur in those lightly diluted rods in which the less-stable binder char constitutes more than 32 wt% of the fired matrix. (author)

  14. EFFECT OF CROP ROTATION AND LONG TERM FERTILIZATION ON THE CARBON AND GLOMALIN CONTENT IN THE SOIL

    Directory of Open Access Journals (Sweden)

    Piotr WOJEWÓDZKI

    2012-12-01

    Full Text Available The research was performed on the basis of soil samples taken from a multi-year long fertilization experiment carried out in Skierniewice. The source of samples was soil under potato and rye cultivated in monoculture and in the 5-fields rotation system. The following combinations of fertilization were concerned: Ca, NPK and CaNPK (doses since 1976: 1.6 t·ha-1 CaO every 4 years in monoculture and 2 t·ha-1 CaO every 5 years in crop rotation, 90 kg·ha-1 N, 26 kg·ha-1 P, 91 kg·ha-1 K. Laboratory analyzes involved determination of total organic carbon (TOC and glomalin operationally described as a total glomalin related soil protein (TGRSP. It was found that regardless of cultivated plants and the method of fertilization, only cultivation system such as rotation and monoculture significantly influenced the content of TGRSP. TOC was significantly influenced by interaction between species of cultivated plant and the system of cultivation. The analyzed factors within the method of cultivation (monoculture and crop rotation did not influence significantly the TGRSP content while cultivated plant species, in monoculture, significantly influenced on TOC content. There was also noted positive correlation (r = 0.72 between TGRSP and TOC.

  15. Oxidation kinetics and mechanisms of carbon/carbon composites and their components in water vapour at high temperatures

    International Nuclear Information System (INIS)

    Qin, Fei; Peng, Li-na; He, Guo-qiang; Li, Jiang; Yan, Yong

    2015-01-01

    Highlights: • 4D-C/C composite was fabricated using carbon fibre and coal tar pitch. • The rate of mass loss and oxidation kinetics parameters of fibres-H 2 O and matrix-H 2 O are obtained. • The rate of mass loss and oxidation kinetics parameters of C/C–H 2 O are obtained. • Oxidation rate of the fibre bundle is greater than the oxidation rate of the matrix. - Abstract: Thermogravimetric analysis and scanning electron microscopy were used to study the oxidation kinetics of four-direction carbon/carbon composites and their components (fibres and matrices) in a H 2 O–Ar atmosphere at high temperatures. The oxidation processes were restricted to reaction-limited oxidation. The rate of mass loss was estimated for the four-direction carbon/carbon composites and their components at high temperature. The pressure exponent for the reaction of the carbon/carbon composites with H 2 O was 0.59, and the pre-exponential factor and activation energy for the reactions of H 2 O with the carbon/carbon composites, carbon fibres and matrices were determined

  16. Preparation of nitrogen-doped biomass-derived carbon nanofibers/graphene aerogel as a binder-free electrode for high performance supercapacitors

    Science.gov (United States)

    Zhang, Yimei; Wang, Fei; Zhu, Hao; Zhou, Lincheng; Zheng, Xinliang; Li, Xinghua; Chen, Zhuang; Wang, Yue; Zhang, Dandan; Pan, Duo

    2017-12-01

    Carbon materials derived from various biomasses have aroused forceful interest from scientific community based on their abundant resource, low cost, environment friendly and easy fabrication. Herein, the method has been developed to prepare nitrogen-doped biomass-derived carbon nanofibers/graphene aerogel (NCGA) as the binder-free electrode for supercapacitors. Ethylenediamine (EDA) is select as nitrogen source for its high nitrogen content and strong interaction with graphene oxide (GO) and cellulose nanofibers (CNFs) via hydrothermal self-assembly method to form hybrid hydrogel, and finally converts to NCGA by freeze-drying and carbonization. After carbonization the insulated CNFs converted to high conductivity carbon nanofibers. The NCGA electrode exhibits a high specific capacitance of 289 F g-1 at 5 mV s-1 and high stability of 90.5% capacitance retention ratio after 5000 cycles at 3 A g-1. This novel biomass electrode could be potential candidate for high performance supercapacitors.

  17. Effect of PVA fiber content on creep property of fiber reinforced high-strength concrete columns

    Science.gov (United States)

    Xu, Zongnan; Wang, Tao; Wang, Weilun

    2018-04-01

    The effect of PVA (polyvinyl alcohol) fiber content on the creep property of fiber reinforced high-strength concrete columns was investigated. The correction factor of PVA fiber content was proposed and the creep prediction model of ACI209 was modified. Controlling the concrete strength as C80, changing the content of PVA fiber (volume fraction 0%, 0.25%, 0.5%, 1% respectively), the creep experiment of PVA fiber reinforced concrete columns was carried out, the creep coefficient of each specimen was calculated to characterize the creep property. The influence of PVA fiber content on the creep property was analyzed based on the creep coefficient and the calculation results of several frequently used creep prediction models. The correction factor of PVA fiber content was proposed to modify the ACI209 creep prediction model.

  18. Highly nitrogen-doped carbon capsules: scalable preparation and high-performance applications in fuel cells and lithium ion batteries.

    Science.gov (United States)

    Hu, Chuangang; Xiao, Ying; Zhao, Yang; Chen, Nan; Zhang, Zhipan; Cao, Minhua; Qu, Liangti

    2013-04-07

    Highly nitrogen-doped carbon capsules (hN-CCs) have been successfully prepared by using inexpensive melamine and glyoxal as precursors via solvothermal reaction and carbonization. With a great promise for large scale production, the hN-CCs, having large surface area and high-level nitrogen content (N/C atomic ration of ca. 13%), possess superior crossover resistance, selective activity and catalytic stability towards oxygen reduction reaction for fuel cells in alkaline medium. As a new anode material in lithium-ion battery, hN-CCs also exhibit excellent cycle performance and high rate capacity with a reversible capacity of as high as 1046 mA h g(-1) at a current density of 50 mA g(-1) after 50 cycles. These features make the hN-CCs developed in this study promising as suitable substitutes for the expensive noble metal catalysts in the next generation alkaline fuel cells, and as advanced electrode materials in lithium-ion batteries.

  19. High speed capacitor-inverter based carbon nanotube full adder.

    Science.gov (United States)

    Navi, K; Rashtian, M; Khatir, A; Keshavarzian, P; Hashemipour, O

    2010-03-18

    Carbon Nanotube filed-effect transistor (CNFET) is one of the promising alternatives to the MOS transistors. The geometry-dependent threshold voltage is one of the CNFET characteristics, which is used in the proposed Full Adder cell. In this paper, we present a high speed Full Adder cell using CNFETs based on majority-not (Minority) function. Presented design uses eight transistors and eight capacitors. Simulation results show significant improvement in terms of delay and power-delay product in comparison to contemporary CNFET Adder Cells. Simulations were carried out using HSPICE based on CNFET model with 0.6 V VDD.

  20. High carbon microalloyed martensitic steel with ultrahigh strength-ductility

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Shengwei; Liu, Yu; Hao, Qingguo [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang, Ying [School of Mechanical Engineering, Shanghai Dianji University, Shanghai 200245 (China); Chen, Nailu, E-mail: nlchen@sjtu.edu.cn [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Zuo, Xunwei; Rong, Yonghua [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2016-04-29

    Based on the idea of rising the mechanical stability of retained austenite by the addition of Si in Fe-Mn based steels, an Fe-0.63C-1.52Mn-1.49Si-0.62Cr-0.036Nb was designed, then its hot rolled plate was successively tread by normalization process as pretreatment of novel quenching-partitioning-tempering (Q-P-T) process. Product of tensile and elongation (PSE) of 53.94 GPa% were obtained for this high carbon Q-P-T martensitic steel, and the PSE (40.18 GPa%) obtained by the conversion of tensile sample size using Oliver formula still is more excellent PSE than those of other microalloyed advanced high strength steels reported. The microstructural characterization reveals origin of ultrahigh PSE resulting from both the increase of considerable and dispersed carbon enriched retained austenite with relative high mechanical stability in volume fraction and the decrease of brittle twin-type martensite with the sensitivity of notch.

  1. Effects of Propylene Carbonate Content in CsPF6-Containing Electrolytes on the Enhanced Performances of Graphite Electrode for Lithium-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jianming; Yan, Pengfei; Cao, Ruiguo; Xiang, Hongfa; Engelhard, Mark H.; Polzin, Bryant; Wang, Chong M.; Zhang, Jiguang; Xu, Wu

    2016-02-10

    Cesium salt has been demonstrated as an efficient electrolyte additive in suppressing the lithium (Li) dendrite formation and directing the formation of an ultrathin and stable solid electrolyte interphase (SEI) even in propylene carbonate (PC)-ethylene carbonate (EC)-based electrolytes. Here, we further investigate the effect of PC content in the presence of CsPF6 additive (0.05 M) on the performances of graphite electrode in Li||graphite half cells and in graphite||LiNi0.80Co0.15Al0.05O2 (NCA) full cells. It is found that the performance of graphite electrode is also affected by PC content even though CsPF6 additive is present in the electrolytes. An optimal PC content of 20% by weight in the solvent mixtures is identified. The enhanced electrochemical performance of graphite electrode is attributed to the synergistic effects of the Cs+ additive and the PC solvent. The formation of a robust, ultrathin and compact SEI layer containing lithium-enriched species on the graphite electrode, directed by Cs+, effectively suppresses the PC co-intercalation and thus prevents the graphite exfoliation. This SEI layer is only permeable for de-solvated Li+ ions and allows fast Li+ ion transport through it, which therefore largely alleviates the Li dendrite formation on graphite electrode during lithiation even at high current densities. The presence of low-melting-point PC solvent also enables the sustainable operation of the graphite||NCA full cells under a wide spectrum of temperatures. The fundamental findings of this work shed light on the importance of manipulating/maintaining the electrode/electrolyte interphasial stability in a variety of energy storage devices.

  2. Short-term contributions of cover crop surface residue return to soil carbon and nitrogen contents in temperate Australia.

    Science.gov (United States)

    Zhou, Xiaoqi; Wu, Hanwen; Li, Guangdi; Chen, Chengrong

    2016-11-01

    Cover crop species are usually grown to control weeds. After cover crop harvest, crop residue is applied on the ground to improve soil fertility and crop productivity. Little information is available about quantifying the contributions of cover crop application to soil total carbon (C) and nitrogen (N) contents in temperate Australia. Here, we selected eight cover crop treatments, including two legume crops (vetch and field pea), four non-legume crops (rye, wheat, Saia oat, and Indian mustard), a mixture of rye and vetch, and a nil-crop control in temperate Australia to calculate the contributions of cover crops (crop growth + residue decomposition) to soil C and N contents. Cover crops were sown in May 2009 (autumn). After harvest, the crop residue was placed on the soil surface in October 2009. Soil and crop samples were collected in October 2009 after harvest and in May 2010 after 8 months of residue decomposition. We examined cover crop residue biomass, soil and crop total C and N contents, and soil microbial biomass C and N contents. The results showed that cover crop application increased the mean soil total C by 187-253 kg ha -1 and the mean soil total N by 16.3-19.1 kg ha -1 relative to the nil-crop treatment, except for the mixture treatment, which had similar total C and N contents to the nil-crop control. Cover crop application increased the mean soil microbial biomass C by 15.5-20.9 kg ha -1 and the mean soil microbial biomass N by 4.5-10.2 kg ha -1 . We calculated the apparent percentage of soil total C derived from cover crop residue C losses and found that legume crops accounted for 10.6-13.9 %, whereas non-legume crops accounted for 16.4-18.4 % except for the mixture treatment (0.2 %). Overall, short-term cover crop application increased soil total C and N contents and microbial biomass C and N contents, which might help reduce N fertilizer use and improve sustainable agricultural development.

  3. Effects of Propylene Carbonate Content in CsPF 6 -Containing Electrolytes on the Enhanced Performances of Graphite Electrode for Lithium-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jianming; Yan, Pengfei; Cao, Ruiguo; Xiang, Hongfa [School of; Engelhard, Mark H.; Polzin, Bryant J. [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States; Wang, Chongmin; Zhang, Ji-Guang; Xu, Wu

    2016-02-15

    The effects Of propylene carbonate (PC) content in CsPF6-containing electrolytes on the performances of graphite electrode in lithium half cells and in graphite parallel to LiNi0.80Co0.15Al0.05O2 (NCA) full cells are investigated. It is found that the performance of graphite electrode is significantly-affected by PC content in the CsPF6-containing electrolytes. An optimal PC content of 20% by weight in the solvent mixtures is identified. The enhanced electrochemical performance of graphite electrode can be attributed to the synergistic effects of the PC solvent and the Cs+ additive. The synergistic effects of Cs+ additive and appropriate amount of PC enable the formation of a robust, ultrathin, and compact solid electrolyte interphase (SEI) layer on the surface of graphite electrode, which is only permeable for desolvated Li+ ions and allows fast Li+ ion transport through it. Therefore, this SEI layer effectively suppresses the PC cointercalation and largely alleviates the Li dendrite formation on graphite electrode during lithiation even at relatively high current densities. The presence of low-melting-point PC solvent improves the sustainable operation of graphite parallel to NCA full cells under a wide temperature range. The fundamental findings also shed light On the importance of manipulating/maintaining the electrode/electrolyte interphasial stability in various energy-storage devices.

  4. Uranium recovery by leaching with sodium carbonate at high temperature and pressure

    International Nuclear Information System (INIS)

    Soerensen, E.; Koefoed, S.; Lundgaard, T.

    1990-09-01

    An alkaline rock from the Ilimaussaq instrusion, SW Greenland, was proposed as a source of uranium. Its principal uranium bearing mineral, Steenstrupine, is a complex sodium REE phosphosilicate in which Fe, Mn, Th and U are minor constituents. A special feature of this ore body is the content of water soluble minerals: NaF (Villiaumite), Na 2 Si 2 O 5 (Natrosilite) and an organic substance which displays the characteristics of humus. Sulfides are sparse, the most important one being ZnS (Sphalerite) of which the content is generally less than 0.5%. In the mineral under consideration (Lujavrite) the Steenstrupine is mainly finelay disseminated throughout the rock, yielding a uranium content of 300-400 ppm and thorium content of 800-1000 ppm. Laboratory tests indicated that high temperature carbonate leaching was necessary to decompose Steenstrupine. The optium temperature was shown to be 260 deg. C and the leach liquor composition 120 g/l of NaHCO 3 and 20 g/l of Na 2 C0 3 . Addition of oxygen is necessary. The process was developed to industrial scale in a continuous pipe autoclave with a retention time of 20 min. After filtering on a belt filter, the liquor was recycled several times to obtain a higher U-concentration. By reductive precipitation with iron powder a raw UO 2 was obtained. It was purified after dissolution in HNO 3 . An overall yield of 80% could be obtained. (author) 32 tabs., 13 ills., 24 refs

  5. Oxidation of an activated carbon commercial and characterization of the content of superficial acid groups

    International Nuclear Information System (INIS)

    Cortes, Juan Carlos; Giraldo Liliana; Garcia, Andres A; Garcia, Cesar; Moreno, Juan C

    2008-01-01

    The changes of the surface acid groups of an activated commercial carbon after placing it under oxidation treatment with nitric acid are studied. The time used was in the range 1.5 and 9 hours, the concentrations range was from 4 to 7 molL -1 . The study included the determination of immersion enthalpy. Boehm's type titrations, FTIR, and pH at the point of zero charge, pH p zc. It was found that total acid groups are in a range from 0.207 mmolg -1 to 1.247 mmolg -1 , and that they are proportional to the immersion enthalpy in NaOH that are between 40 and 54Jg -1 . The pH p zc decreases with the oxidation treatment and have values between 8.3 and 4.3

  6. Direct synthesis of highly porous interconnected carbon nanosheets and their application as high-performance supercapacitors.

    Science.gov (United States)

    Sevilla, Marta; Fuertes, Antonio B

    2014-05-27

    An easy, one-step procedure is proposed for the synthesis of highly porous carbon nanosheets with an excellent performance as supercapacitor electrodes. The procedure is based on the carbonization of an organic salt, i.e., potassium citrate, at a temperature in the 750-900 °C range. In this way, carbon particles made up of interconnected carbon nanosheets with a thickness of <80 nm are obtained. The porosity of the carbon nanosheets consists essentially of micropores distributed in two pore systems of 0.7-0.85 nm and 0.95-1.6 nm. Importantly, the micropore sizes of both systems can be enlarged by simply increasing the carbonization temperature. Furthermore, the carbon nanosheets possess BET surface areas in the ∼1400-2200 m(2) g(-1) range and electronic conductivities in the range of 1.7-7.4 S cm(-1) (measured at 7.1 MPa). These materials behave as high-performance supercapacitor electrodes in organic electrolyte and exhibit an excellent power handling ability and a superb robustness over long-term cycling. Excellent results were obtained with the supercapacitor fabricated from the material synthesized at 850 °C in terms of both gravimetric and volumetric energy and power densities. This device was able to deliver ∼13 Wh kg(-1) (5.2 Wh L(-1)) at an extremely high power density of 78 kW kg(-1) (31 kW L(-1)) and ∼30 Wh kg(-1) (12 Wh L(-1)) at a power density of 13 kW kg(-1) (5.2 kW L(-1)) (voltage range of 2.7 V).

  7. Modeled effects on permittivity measurements of water content in high surface area porous media

    International Nuclear Information System (INIS)

    Jones, S.B.; Or, Dani

    2003-01-01

    Time domain reflectometry (TDR) has become an important measurement technique for determination of porous media water content and electrical conductivity due to its accuracy, fast response and automation capability. Water content is inferred from the measured bulk dielectric constant based on travel time analysis along simple transmission lines. TDR measurements in low surface area porous media accurately describe water content using an empirical relationship. Measurement discrepancies arise from dominating influences such as bound water due to high surface area, extreme aspect ratio particles or atypical water phase configuration. Our objectives were to highlight primary factors affecting dielectric permittivity measurements for water content determination in porous mixtures, and demonstrate the influence of these factors on mixture permittivity as predicted by a three-phase dielectric mixture model. Modeled results considering water binding, higher porosity, constituent geometry or phase configuration suggest any of these effects individually are capable of causing permittivity reduction, though all likely contribute in high surface area porous media

  8. Kinethical Aspects of High Solid Contents Copoly(Styrene/Butylacrylate-Cloisite 30B Nanocomposites

    Directory of Open Access Journals (Sweden)

    M. Mirzataheri

    2014-01-01

    Full Text Available High solid content poly (styrene-co-butyl acrylate latex ( with 20% and 40% solid content including high amounts of Cloisite 30B (7 wt% and 10 wt% were kinetically investigated. Gravimetric method via measuring the rate of polymerization, number of particles and average number of radicals per particle was used. Results showed that by increasing the solid content; the average diameter of polymer particles decreased. Studies on the polymerization rate depict that the increase in polymer particle size provides more average reactive radicals per polymer particle, which increased from 0.48 to 0.88 for the sample containing 7 wt% clay and 20 wt% solid content. Observed armored particles with honeycomb morphology is the most novelty of this research work, which is suitable for making barrier packaging films.

  9. Coupled land surface-subsurface hydrogeophysical inverse modeling to estimate soil organic carbon content and explore associated hydrological and thermal dynamics in the Arctic tundra

    Science.gov (United States)

    Phuong Tran, Anh; Dafflon, Baptiste; Hubbard, Susan S.

    2017-09-01

    Quantitative characterization of soil organic carbon (OC) content is essential due to its significant impacts on surface-subsurface hydrological-thermal processes and microbial decomposition of OC, which both in turn are important for predicting carbon-climate feedbacks. While such quantification is particularly important in the vulnerable organic-rich Arctic region, it is challenging to achieve due to the general limitations of conventional core sampling and analysis methods, and to the extremely dynamic nature of hydrological-thermal processes associated with annual freeze-thaw events. In this study, we develop and test an inversion scheme that can flexibly use single or multiple datasets - including soil liquid water content, temperature and electrical resistivity tomography (ERT) data - to estimate the vertical distribution of OC content. Our approach relies on the fact that OC content strongly influences soil hydrological-thermal parameters and, therefore, indirectly controls the spatiotemporal dynamics of soil liquid water content, temperature and their correlated electrical resistivity. We employ the Community Land Model to simulate nonisothermal surface-subsurface hydrological dynamics from the bedrock to the top of canopy, with consideration of land surface processes (e.g., solar radiation balance, evapotranspiration, snow accumulation and melting) and ice-liquid water phase transitions. For inversion, we combine a deterministic and an adaptive Markov chain Monte Carlo (MCMC) optimization algorithm to estimate a posteriori distributions of desired model parameters. For hydrological-thermal-to-geophysical variable transformation, the simulated subsurface temperature, liquid water content and ice content are explicitly linked to soil electrical resistivity via petrophysical and geophysical models. We validate the developed scheme using different numerical experiments and evaluate the influence of measurement errors and benefit of joint inversion on the

  10. Fabrication of mesoporous and high specific surface area lanthanum carbide-carbon nanotube composites

    International Nuclear Information System (INIS)

    Biasetto, L.; Carturan, S.; Maggioni, G.; Zanonato, P.; Bernardo, P. Di; Colombo, P.; Andrighetto, A.; Prete, G.

    2009-01-01

    Mesoporous lanthanum carbide-carbon nanotube composites were produced by means of carbothermal reaction of lanthanum oxide, graphite and multi-walled carbon nanotube mixtures under high vacuum. Residual gas analysis revealed the higher reactivity of lanthanum oxide towards carbon nanotubes compared to graphite. After sintering, the composites revealed a specific surface area increasing with the amount of carbon nanotubes introduced. The meso-porosity of carbon nanotubes was maintained after thermal treatment.

  11. Carbon exchange in biological soil crust communities under differential temperatures and soil water contents: implications for global change

    Science.gov (United States)

    Grote, Edmund E.; Belnap, Jayne; Housman, David C.; Sparks, Jed P.

    2010-01-01

    Biological soil crusts (biocrusts) are an integral part of the soil system in arid regions worldwide, stabilizing soil surfaces, aiding vascular plant establishment, and are significant sources of ecosystem nitrogen and carbon. Hydration and temperature primarily control ecosystem CO2 flux in these systems. Using constructed mesocosms for incubations under controlled laboratory conditions, we examined the effect of temperature (5-35 1C) and water content (WC, 20-100%) on CO2 exchange in light cyanobacterially dominated) and dark cyanobacteria/lichen and moss dominated) biocrusts of the cool Colorado Plateau Desert in Utah and the hot Chihuahuan Desert in New Mexico. In light crusts from both Utah and New Mexico, net photosynthesis was highest at temperatures 430 1C. Net photosynthesis in light crusts from Utah was relatively insensitive to changes in soil moisture. In contrast, light crusts from New Mexico tended to exhibit higher rates of net photosynthesis at higher soil moisture. Dark crusts originating from both sites exhibited the greatest net photosynthesis at intermediate soil water content (40-60%). Declines in net photosynthesis were observed in dark crusts with crusts from Utah showing declines at temperatures 425 1C and those originating from New Mexico showing declines at temperatures 435 1C. Maximum net photosynthesis in all crust types from all locations were strongly influenced by offsets in the optimal temperature and water content for gross photosynthesis compared with dark respiration. Gross photosynthesis tended to be maximized at some intermediate value of temperature and water content and dark respiration tended to increase linearly. The results of this study suggest biocrusts are capable of CO2 exchange under a wide range of conditions. However, significant changes in the magnitude of this exchange should be expected for the temperature and precipitation changes suggested by current climate models.

  12. Seismic Performance Comparison of a High-Content SDA Frame and Standard RC Frame

    OpenAIRE

    van de Lindt, John W.; Rechan, R. Karthik

    2011-01-01

    This study presents the method and results of an experiment to study the seismic behavior of a concrete portal frame with fifty percent of its cement content replaced with a spray dryer ash (SDA). Based on multiple-shake-table tests, the high content SDA frame was found to perform as well as the standard concrete frame for two earthquakes exceeding design-level intensity earthquakes. Hence, from a purely seismic/structural standpoint, it may be possible to replace approximately fifty percen...

  13. Ultramicroporous carbon with extremely narrow pore distribution and very high nitrogen doping for efficient methane mixture gases upgrading

    KAUST Repository

    Yao, Kexin

    2017-06-24

    It is notably challenging to fabricate heavily heteroatom-doped porous carbonaceous materials with narrow ultramicropore size distributions for highly effective mixed-gas separation. In this study, new carbon-based materials with narrow ultramicropore size (<7 Å) distributions (>95%) and high N doping contents (>10 at%) are fabricated through the pyrolysis of a perchloro-substituted porous covalent triazine-based framework (ClCTF). In particular, the sample prepared at 650 °C (ClCTF-1-650) possesses the highest ultramicropores content (98%) and large N content (12 at%) and demonstrates a very high CH and CO capacity, as well as a low N uptake under ambient conditions. The extraordinarily high CH/N and CO/N selectivities correlate with both the ideal adsorption solution theory (IAST) method and performed dynamic separation experiments (breakthrough experiments). The results reported in this study far exceed the CH/N and CO/N selectivities of previously reported carbon-based adsorbents including various nitrogen-doped ones. These results are believed to be associated with the unusually high N content, as well as the suitably narrow ultramicropore size distribution. This report introduces a new pathway to design porous absorbents with precisely controlled ultramicropores for gas separation.

  14. Effect of high pressure hydrogen on the mechanical characteristics of single carbon fiber

    Science.gov (United States)

    Jeon, Sang Koo; Kwon, Oh Heon; Jang, Hoon-Sik; Ryu, Kwon Sang; Nahm, Seung Hoon

    2018-02-01

    In this study, carbon fiber was exposed to a pressure of 7 MPa for 24 h in high pressure chamber. The tensile test for carbon fiber was conducted to estimate the effect on the high pressure hydrogen in the atmosphere. To determine the tensile strength and Weibull modulus, approximately thirty carbon fiber samples were measured in all cases, and carbon fiber exposed to high pressure argon was evaluated to verify only the effect of hydrogen. Additionally, carbon fiber samples were annealed at 1950 °C for 1 h for a comparison with normal carbon fiber and then tested under identical conditions. The results showed that the tensile strength scatter of normal carbon fiber exposed to hydrogen was relatively wider and the Weibull modulus was decreased. Moreover, the tensile strength of the annealed carbon fiber exposed to hydrogen was increased, and these samples indicated a complex Weibull modulus because the hydrogen stored in the carbon fiber influenced the mechanical characteristic.

  15. Tobacco Stem-Based Activated Carbons for High Performance Supercapacitors

    Science.gov (United States)

    Xia, Xiaohong; Liu, Hongbo; Shi, Lei; He, Yuede

    2012-09-01

    Tobacco stem-based activated carbons (TS-ACs) were prepared by simple KOH activation and their application as electrodes in the electrical double layer capacitor (EDLC) performed successfully. The BET surface area, pore volume, and pore size distribution of the TS-ACs were evaluated based on N2 adsorption isotherms at 77 K. The surface area of the obtained activated carbons varies over a wide range (1472.8-3326.7 m2/g) and the mesoporosity was enhanced significantly as the ratio of KOH to tobacco stem (TS) increased. The electrochemical behaviors of series TS-ACs were characterized by means of galvanostatic charging/discharging, cyclic voltammetry, and impedance spectroscopy. The correlation between electrochemical properties and pore structure was investigated. A high specific capacitance value as 190 F/g at 1 mA/cm2 was obtained in 1 M LiPF6-EC/DMC/DEC electrolyte solution. Furthermore, good performance is also achieved even at high current densities. A development of new use for TS into a valuable energy storage material is explored.

  16. Activated polyaniline-based carbon nanoparticles for high performance supercapacitors

    International Nuclear Information System (INIS)

    Zhou, Jin; Zhu, Tingting; Xing, Wei; Li, Zhaohui; Shen, Honglong; Zhuo, Shuping

    2015-01-01

    Polyaniline (PANI) nanoparticles have been prepared by disperse polymerization of aniline in the presence of poly(4-styrenesulfonate). The PANI nanoparticles are further subjected to pyrolysis treatment and chemical-activation to prepare the activated nitrogen-doped carbon nanoparticles (APCNs). The porosity, structure and nitrogen-doped surface chemistry are analyzed by a varies of means, such as scanning electron microscopy, transition electron microscopy, N 2 sorption, X-ray diffraction and X-ray photoelectron spectroscopy. The capacitive performance of the APCNs materials are test in 6 M KOH electrolyte. Benefitting from the abundant micropores with short length, large specific surface area, hierarchical porosity and heteroatom-doped polar pore surface, the APCNs materials exhibit v exhibit very high specific capacitance up to 341 F g −1 , remarkable power capability and excellent long-term cyclic stability (96.6% after 10 000 cycles). At 40 A g −1 , APCN-2 carbon shows a capacitance of 164 F g −1 , responding to a high energy and power densities of 5.7 Wh kg −1 and 10 000 W kg −1

  17. Functional Carbon Nanotube/Mesoporous Carbon/MnO2 Hybrid Network for High-Performance Supercapacitors

    Directory of Open Access Journals (Sweden)

    Tao Tao

    2014-01-01

    Full Text Available A functional carbon nanotube/mesoporous carbon/MnO2 hybrid network has been developed successfully through a facile route. The resulting composites exhibited a high specific capacitance of 351 F/g at 1 A g−1, with intriguing charge/discharge rate performance and cycling stability due to a synergistic combination of large surface area and excellent electron-transport capabilities of MnO2 with the good conductivity of the carbon nanotube/mesoporous carbon networks. Such composite shows great potential to be used as electrodes for supercapacitors.

  18. High performance thiol-ene thermosets based on fully bio-based poly(limonene carbonate)s

    NARCIS (Netherlands)

    Li, C.; Johansson, M.; Sablong, R.J.; Koning, C.E.

    2017-01-01

    High glass transition temperature (Tg) thiol-ene networks (TENs) based on poly(limonene carbonate)s (PLCs), derived from orange oils and of potential degradability are described here. PLCs with moderate molecular weight were prepared by copolymerization of limonene oxide with CO2 and subsequent

  19. Molten salt synthesis of nitrogen and oxygen enriched hierarchically porous carbons derived from biomass via rapid microwave carbonization for high voltage supercapacitors

    Science.gov (United States)

    Cheng, Yinfeng; Li, Baoqiang; Huang, Yanjuan; Wang, Yaming; Chen, Junchen; Wei, Daqing; Feng, Yujie; Jia, Dechang; Zhou, Yu

    2018-05-01

    Nitrogen and oxygen enriched hierarchically porous carbons (NOHPCs) derived from biomass have been successfully prepared by rapid microwave carbonization coupled with molten salt synthesis method in only 4 min. ZnCl2 plays important roles as microwave absorber, chemical activation agent and porogen in this process. NOHPC-1:10 sample possesses the maximum specific surface area of 1899 m2 g-1 with a pore volume of 1.16 cm3 g-1 and mesopore ratio of 70%, as well as nitrogen content of 5.30 wt% and oxygen content of 14.12 wt%. When evaluated as an electrode in a three-electrode system with 6 M KOH electrolyte, the material exhibits a high specific capacitance of 276 F g-1 at 0.2 A g-1, with a good rate capability of 90.9% retention at 10 A g-1. More importantly, the symmetric supercapacitor based on NOHPC-1:10 in 1 M Na2SO4 electrolyte exhibits a high energy density of 13.9 Wh kg-1 at a power density of 120 W kg-1 in a wide voltage window of 0-1.6 V, an excellent cycling stability with 95% of capacitance retention after 10,000 cycles. Our strategy provides a facile and rapid way for the preparation of advanced carbon materials derived from biomass towards energy storage applications.

  20. Manufacturing High-Quality Carbon Nanotubes at Lower Cost

    Science.gov (United States)

    Benavides, Jeanette M.; Lidecker, Henning

    2004-01-01

    A modified electric-arc welding process has been developed for manufacturing high-quality batches of carbon nanotubes at relatively low cost. Unlike in some other processes for making carbon nanotubes, metal catalysts are not used and, consequently, it is not necessary to perform extensive cleaning and purification. Also, unlike some other processes, this process is carried out at atmospheric pressure under a hood instead of in a closed, pressurized chamber; as a result, the present process can be implemented more easily. Although the present welding-based process includes an electric arc, it differs from a prior electric-arc nanotube-production process. The welding equipment used in this process includes an AC/DC welding power source with an integral helium-gas delivery system and circulating water for cooling an assembly that holds one of the welding electrodes (in this case, the anode). The cathode is a hollow carbon (optionally, graphite) rod having an outside diameter of 2 in. (approximately equal to 5.1 cm) and an inside diameter of 5/8 in. (approximately equal to 1.6 cm). The cathode is partly immersed in a water bath, such that it protrudes about 2 in. (about 5.1 cm) above the surface of the water. The bottom end of the cathode is held underwater by a clamp, to which is connected the grounding cable of the welding power source. The anode is a carbon rod 1/8 in. (approximately equal to 0.3 cm) in diameter. The assembly that holds the anode includes a thumbknob- driven mechanism for controlling the height of the anode. A small hood is placed over the anode to direct a flow of helium downward from the anode to the cathode during the welding process. A bell-shaped exhaust hood collects the helium and other gases from the process. During the process, as the anode is consumed, the height of the anode is adjusted to maintain an anode-to-cathode gap of 1 mm. The arc-welding process is continued until the upper end of the anode has been lowered to a specified height

  1. Innovation management and marketing in the high-tech sector: A content analysis of advertisements

    DEFF Research Database (Denmark)

    Gerhard, D.; Brem, Alexander; Baccarella, Ch.

    2011-01-01

    Advertizing high-technology products is a tricky and critical task for every company, since it means operating in an environment with high market uncertainty. The work presents results of a content analysis of 110 adverts for consumer electronics products which examines how these products and the...

  2. Enzymatic pre-treatment of high content cellulosic feedstock improves biogas production

    Science.gov (United States)

    Animal wastes with high lignin and cellulosic contents can serve as the feedstock for biogas production (mainly methane) that could be used as alternative energy source. However, these high lignin and cellulosic feedstocks are quite recalcitrant to be readily utilized by methanogens to produce ben...

  3. Inferring brown carbon content from UV aerosol absorption measurements during biomass burning season

    Science.gov (United States)

    Mok, J.; Krotkov, N. A.; Arola, A. T.; Torres, O.; Jethva, H. T.; Andrade, M.; Labow, G. J.; Eck, T. F.; Li, Z.; Dickerson, R. R.; Stenchikov, G. L.; Osipov, S.

    2015-12-01

    Measuring spectral dependence of light absorption by colored organic or "brown" carbon (BrC) is important, because of its effects on photolysis rates of ozone and surface ultraviolet (UV) radiation. Enhanced UV spectral absorption by BrC can in turn be exploited for simultaneous retrievals of BrC and black carbon (BC) column amounts in field campaigns. We present an innovative ground-based retrieval of BC and BrC volume fractions and their mass absorption efficiencies during the biomass burning season in Santa Cruz, Bolivia in September-October 2007. Our method combines retrieval of BC volume fraction using AERONET inversion in visible wavelengths with the inversion of total BC+BrC absorption (i.e., column effective imaginary refractive index, kmeas) using Diffuse/Direct irradiance measurements in UV wavelengths. First, we retrieve BrC volume fraction by fitting kmeas at 368nm using Maxwell-Garnett (MG) mixing rules assuming: (1) flat spectral dependence of kBC, (2) known value of kBrC at 368nm from laboratory absorption measurements or smoke chamber experiments, and (3) known BC volume fraction from AERONET inversion. Next, we derive kBrC in short UVB wavelengths by fitting kmeas at 305nm, 311nm, 317nm, 325nm, and 332nm using MG mixing rules and fixed volume fractions of BC and BrC. Our retrievals show larger than expected spectral dependence of kBrC in UVB wavelengths, implying reduced surface UVB irradiance and inhibited photolysis rates of surface ozone destruction. We use a one-dimensional chemical box model to show that the observed strong wavelength dependence of BrC absorption leads to inhibited photolysis of ozone to O(1D), a loss mechanism, while having little impact or even accelerating photolysis of NO2, an ozone production mechanism. Although BC only absorption in biomass burning aerosols is important for climate radiative forcing in the visible wavelengths, additional absorption by BrC is important because of its impact on surface UVB radiation

  4. Austenitic stainless steel alloys with high nickel contents in high temperature liquid metal systems

    International Nuclear Information System (INIS)

    Konvicka, H.R.; Schwarz, N.F.

    1981-01-01

    Fe-Cr-Ni base alloys (nickel content: from 15 to 70 wt%, Chromium content: 15 wt%, iron: balance) together with stainless steel (W.Nr. 1.4981) have been exposed to flowing liquid sodium at 730 0 C in four intervals up to a cumulative exposure time of 1500 hours. Weight change data and the results of post-exposition microcharacterization of specimens are reported. The corrosion rates increase with increasing nickel content and tend to become constant after longer exposure times for each alloy. The corrosion rate of stainless steel is considerably reduced due to the presence of the base alloys. Different kinetics of nickel poor (up to 35% nickel) and nickel rich (> 50% nickel) alloys and nickel transport from nickel rich to nickel poor material is observed. (orig.)

  5. Activated Fraction Of Black Carbon By Cloud Droplets And Ice Crystals At The High Alpine Site Jungfraujoch (3580 m asl)

    Energy Technology Data Exchange (ETDEWEB)

    Cozic, J.; Mertes, S. [IFT Leipzig (Georgia); Verheggen, B.; Petzold, A. [DLR, Oberpfaffenhofen (Georgia); Weingartner, E.; Baltensperger, U.

    2005-03-01

    Measurements of black carbon (BC) were made in winter and summer 2004 at the high Alpine site Jungfraujoch in order to study the activation of BC into cloud droplets and ice crystals. Main results showed that the activated fraction represents 61% in summer and that for a large temperature range between -25 C and 5 C, the activated BC fraction increases with increasing temperature and increasing liquid water content. (author)

  6. Diagnostic value of the evaluation of the glycogen content in muscle diseases by carbon 13 nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Jehenson, P.; Syrota, A.; Labrune, P.; Odievre, M.; Fardeau, M.

    1995-01-01

    We have developed a method for the evaluation of the muscle glycogen content by natural abundance C13 NMR and we here evaluate its diagnostic value on a large number of muscle diseases (20 glycogenoses and 42 other myopathies) and 8 normal subjects. The results show high values of the glycogen/creatine ratio in muscle glycogenoses, with no overlap with other diseased or normal subjects. This evaluation of the muscle glycogen content, which is performed at rest and thus easily applicable, in particular for children, is thus very sensitive and specific for the diagnosis of muscle glycogenosis. (authors). 9 refs

  7. Optimization of Inactive Material Content in Lithium Iron Phosphate Electrodes for High Power Applications

    International Nuclear Information System (INIS)

    Ha, Seonbaek; Ramani, Vijay K.; Lu, Wenquan; Prakash, Jai

    2016-01-01

    The electrochemical performance of lithium iron phosphate (LiFePO 4 ) electrodes has been studied to find the optimum content of inactive materials (carbon black + polyvinylidene difluoride [PVDF] polymer binder) and to better understand electrode performance with variation in electrode composition. Trade-offs between inactive material content and electrochemical performance have been characterized in terms of electrical resistance, rate-capability, area-specific impedance (ASI), pulse-power characterization, and energy density calculations. The ASI and electrical conductivity were found to correlate well with ohmic polarization. The results showed that a 80:10:10 (active material: binder: carbon agents) electrode had a higher pulse-power density and energy density at rates above 1C as compared to 90:5:5, 86:7:7 and 70:15:15 formulations, while the 70:15:15 electrode had the highest electrical conductivity of 0.79 S cm −1 . A CB/PVDF ratio of ca. 1.22 was found to be the optimum formulation of inactive material when the LiFePO 4 composition was 80 wt%.

  8. Fabrication of highly conductive carbon nanotube fibers for electrical application

    International Nuclear Information System (INIS)

    Guo, Fengmei; Li, Can; Wei, Jinquan; Xu, Ruiqiao; Zhang, Zelin; Cui, Xian; Wang, Kunlin; Wu, Dehai

    2015-01-01

    Carbon nanotubes (CNTs) have great potential for use as electrical wires because of their outstanding electrical and mechanical properties. Here, we fabricate lightweight CNT fibers with electrical conductivity as high as that of stainless steel from macroscopic CNT films by drawing them through diamond wire-drawing dies. The entangled CNT bundles are straightened by suffering tension, which improves the alignment of the fibers. The loose fibers are squeezed by the diamond wire-drawing dies, which reduces the intertube space and contact resistance. The CNT fibers prepared by drawing have an electrical conductivity as high as 1.6 × 10 6 s m −1 . The fibers are very stable when kept in the air and under cyclic tensile test. A prototype of CNT motor is demonstrated by replacing the copper wires with the CNT fibers. (paper)

  9. Fed-batch cultivation of baker's yeast followed by nitrogen or carbon starvation: effects on fermentative capacity and content of trehalose and glycogen

    DEFF Research Database (Denmark)

    Jørgensen, Henning; Olsson, Lisbeth; Rønnow, B.

    2002-01-01

    , trehalose and glycogen. Nitrogen starvation triggered the accumulation of trehalose and glycogen. After 8 h of starvation, the content of trehalose and glycogen was increased 4-fold and 2-fold, respectively. Carbon starvation resulted in a partial conversion of glycogen into trehalose. The trehalose content...... increased from 45 to 64 mg (g dry-weight)(-1), whereas the glycogen content in the same period was reduced from 55 to 5 mg (g dry-weight)(-1). Glycogen was consumed faster than trehalose during storage of the starved yeast for 1 month. Nitrogen starvation resulted in a decrease in the protein content...

  10. The aging by precipitation of Nb (C,N) in extra low carbon content steel

    International Nuclear Information System (INIS)

    Bruno, J.C.; Kestenbach, H.-J.

    1982-01-01

    Carbonitride precipitation has been studied in a high-niobium acicular - ferrite - type steel. Interphase precipitation occurred only in those samples in which high transformation temperatures led to distinctly polygonal-ferrite microestructures. In this latter case, precipitation occurred during a subsequent aging treatment, with a strong tendency for heterogeneous nucleation on dislocations. (Author) [pt

  11. Energy Saving High-Capacity Moderate Pressure Carbon Dioxide Storage System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Our approach to high-pressure carbon dioxide storage will directly address the challenges associated with storage of compressed carbon dioxide - the need to reduce...

  12. Production of microbial oil with high oleic acid content by Trichosporon capitatum

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hong; Zong, Minhua [State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640 (China); Li, Yuanyuan; Chen, Lei [School of Biosciences and Bioengineering, South China University of Technology, Guangzhou 510640 (China)

    2011-01-15

    Microbial oils with high unsaturated fatty acids content, especially oleic acid content, are good feedstock for high quality biodiesel production. Trichosporon capitatum was found to accumulate lipid with around 80% oleic acid and 89% total unsaturated fatty acids content on nitrogen-limited medium. In order to improve its lipid yield, effects of medium components and culture conditions on cell growth and lipid accumulation were investigated. Optimization of media resulted in a 61% increase in the lipid yield of T. capitatum after cultivation at 28 C and 160 rpm for 6 days. In addition, T. capitatum could grow well on cane molasses and afford a lipid yield comparable to that on synthetic nitrogen-limited medium. The biodiesel from the microbial oil produced by T. capitatum on cane molasses displayed a low cold filter plugging point (-15 C), and so T. capitatum might be a promising strain to provide lipid suitable for high quality biodiesel production. (author)

  13. Enhancing protein to extremely high content in photosynthetic bacteria during biogas slurry treatment.

    Science.gov (United States)

    Yang, Anqi; Zhang, Guangming; Meng, Fan; Lu, Pei; Wang, Xintian; Peng, Meng

    2017-12-01

    This work proposed a novel approach to achieve an extremely high protein content in photosynthetic bacteria (PSB) using biogas slurry as a culturing medium. The results showed the protein content of PSB could be enhanced strongly to 90% in the biogas slurry, which was much higher than reported microbial protein contents. The slurry was partially purified at the same time. Dark-aerobic was more beneficial than light-anaerobic condition for protein accumulation. High salinity and high ammonia of the biogas slurry were the main causes for protein enhancement. In addition, the biogas slurry provided a good buffer system for PSB to grow. The biosynthesis mechanism of protein in PSB was explored according to theoretical analysis. During biogas slurry treatment, the activities of glutamate synthase and glutamine synthetase were increased by 26.55%, 46.95% respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Highly microporous carbons derived from a complex of glutamic acid and zinc chloride for use in supercapacitors

    Science.gov (United States)

    Dong, Xiao-Ling; Lu, An-Hui; He, Bin; Li, Wen-Cui

    2016-09-01

    The selection of carbon precursor is an important factor when designing carbon materials. In this study, a complex derived from L-glutamic acid and zinc chloride was used to prepare highly microporous carbons via facile pyrolysis. L-glutamic acid, a new carbon precursor with nitrogen functionality, coordinated with zinc chloride resulted in a homogeneous distribution of Zn2+ on the molecular level. During pyrolysis, the evaporation of the in situ formed zinc species creates an abundance of micropores together with the inert gases. The obtained carbons exhibit high specific surface area (SBET: 1203 m2 g-1) and a rich nitrogen content (4.52 wt%). In excess of 89% of the pore volume consists of micropores with pore size ranging from 0.5 to 1.2 nm. These carbons have been shown to be suitable for use as supercapacitor electrodes, and have been tested in 6 M KOH where a capacitance of 217 F g-1 was achieved at a current density of 0.5 A g-1. A long cycling life of 30 000 cycles was achieved at a current density of 1 A g-1, with only a 9% loss in capacity. The leakage current through a two-electrode device was measured as 2.3 μA per mg of electrode and the self-discharge characteristics were minimal.

  15. Evaluation of the potentiality of the use of high-carbon microsilica as a pozzolanic material

    International Nuclear Information System (INIS)

    Ferreira, R.L.S.; Pederneiras, C.M.; Costa, T.C.S.; Silva, C.H.R.B.; Anjos, M.A.S.; Nobrega, A.K.

    2016-01-01

    Supplementary Cementitious Materials reduce the production of clinker, which minimizes the environmental impact of cement production and the generation of industrial waste, also improve mechanical behavior and durability. Thus, this article aims to evaluate the potential use of microsilica with high content of carbon as pozzolanic material, based on the requirements of ISO 12653 (ABNT, 2015). The techniques of X-ray fluorescence (XRF), X-ray diffraction (XRD) and compressive strength of mortar of lime and cement (at 7 and 28 days, respectively) were used to evaluate the pozzolanic of the microsilica as a mineral addition. The results indicated that the microsilica has a high amorphous silicon dioxide percentage structure. In the DRX could be possible to analyze the formation of CSH, justifying the good results of mechanical strength, especially with cement. Thus, the mineral admixture used in this research can be considered as a pozzolanic material. (author)

  16. Crystalline and amorphous phases in carbon nitride films produced by intense high-pressure plasma

    International Nuclear Information System (INIS)

    Gurarie, V.N.; Orlov, A.V.; Bursill, L.A.; JuLin, P.; Nugent, K.W.; Chon, J.W.; Prawer, S.

    1997-01-01

    Carbon-nitride films are prepared using a high-intensity pulsed plasma deposition technique. A wide range of nitrogen pressure and discharge intensity are used to investigate their effect on the morphology, nitrogen content, structure, bonding, phase composition and mechanical characteristics of the CN films deposited. Increasing the nitrogen pressure from 0.1 atm to 10 atm results in an increase of nitrogen incorporation into CN films to maximum of 45 at %. Under the high-energy density deposition conditions which involve ablation of the quartz substrate the CN films are found to incorporate in excess of 60 at %N. Raman spectra of these films contain sharp peaks characteristic of a distinct crystalline CN phase. TEM diffraction patterns for the films deposited below 1 atm unambiguously show the presence of micron-sized crystals displaying a cubic symmetry. (authors)

  17. Implications of wall recycling and carbon source locations on core plasma fueling and impurity content in DIII-D

    International Nuclear Information System (INIS)

    Groth, M.; Porter, G.D.; Fenstermacher, M.E.; Lasnier, C.J.; Meyer, W.M.; Rensink, M.E.; Wolf, N.S.; Boedo, J.A.; Moyer, R.A.; Rudakov, D.L.; Brooks, N.H.; Groebner, R.J.; Petrie, T.W.; Owen, L.W.; Wang, G.; Zeng, L.; Watkins, J.G.

    2005-01-01

    Measurement and modeling of the 2-D poloidal D α intensity distribution in DIII-D low and medium density L-mode and ELMy H-mode plasmas indicate that hydrogen neutrals predominantly fuel the core from the divertor X-point region. The 2-D distribution of neutral deuterium and low-charge-state carbon were measured in the divertor and the high-field side midplane scrape-off layer (SOL) using tangentially viewing cameras. The emission in the high-field SOL at the equatorial plane was found to be three to four orders of magnitude lower than at the strike points in the divertor, suggesting a strong divertor particle source. Modeling using the UEDGE/DEGAS codes predicted the poloidal fueling distribution to be dependent on the direction of the ion Bx∇B drift. In plasmas with the Bx∇B drift into the divertor stronger fueling from the inner divertor than from the outer is predicted, due to a lower-temperature and higher-density plasma in the inner leg. UEDGE simulations with carbon produced by both physical and chemical sputtering at the divertor plates and walls only are in agreement with a large set of diagnostic data. The simulations indicate flow reversal in the inner divertor that augments the leakage of carbon ions from the divertor into the core. (author)

  18. Rapid removal of bisphenol A on highly ordered mesoporous carbon.

    Science.gov (United States)

    Sui, Qian; Huang, Jun; Liu, Yousong; Chang, Xiaofeng; Ji, Guangbin; Deng, Shubo; Xie, Tao; Yu, Gang

    2011-01-01

    Bisphenol A (BPA) is of global concern due to its disruption of endocrine systems and ubiquity in the aquatic environment. It is important, therefore, that efforts are made to remove it from the aqueous phase. A novel adsorbent, mesoporous carbon CMK-3, prepared from hexagonal SBA-15 mesoporous silica was studied for BPA removal from aqueous phase, and compared with conventional powdered activated carbon (PAC). Characterization of CMK-3 by transmission electron microscopy (TEM), X-ray diffraction, and nitrogen adsorption indicated that prepared CMK-3 had an ordered mesoporous structure with a high specific surface area of 920 m2/g and a pore-size of about 4.9 nm. The adsorption of BPA on CMK-3 followed a pseudo second-order kinetic model. The kinetic constant was 0.00049 g/(mg x min), much higher than the adsorption of BPA on PAC. The adsorption isotherm fitted slightly better with the Freundlich model than the Langmuir model, and adsorption capacity decreased as temperature increased from 10 to 40 degrees C. No significant influence of pH on adsorption was observed at pH 3 to 9; however, adsorption capacity decreased dramatically from pH 9 to 13.

  19. High dispersity of carbon nanotubes diminishes immunotoxicity in spleen.

    Science.gov (United States)

    Lee, Soyoung; Khang, Dongwoo; Kim, Sang-Hyun

    2015-01-01

    From the various physiochemical material properties, the chemical functionalization order of single-walled carbon nanotubes (swCNTs) has not been considered as a critical factor for modulating immunological responses and toxicological aspects in drug delivery applications. Although most nanomaterials, including carbon nanotubes, are specifically accumulated in spleen, few studies have focused on spleen immunotoxicity. For this reason, this study demonstrated that the dispersity of swCNTs significantly influenced immunotoxicity in vitro and in vivo. For cytotoxicity of swCNTs, MTT assay, reactive oxygen species production, superoxide dismutase activity, cellular uptake, and confocal microscopy were used in macrophages. In the in vivo study, female BALB/c mice were intravenously administered with 1 mg/kg/day of swCNTs for 2 weeks. The body weight, organ weight, hematological change, reverse-transcription polymerase chain reaction, and lymphocyte population were evaluated. Different orders of chemical functionalization of swCNTs controlled immunotoxicity. In short, less-dispersed swCNTs caused cytotoxicity in macrophages and abnormalities in immune organs such as spleen, whereas highly dispersed swCNTs did not result in immunotoxicity. This study clarified that increasing carboxyl groups on swCNTs significantly mitigated immunotoxicity in vitro and in vivo. Our findings clarified the effective immunotoxicological factors of swCNTs by increasing dispersity of swCNTs and provided useful guidelines for the effective use of nanomaterials.

  20. Sulphur, nitrogen and carbon content of Sphagnum capillifolium and Pseudevernia furfuracea exposed in bags in the Naples urban area

    International Nuclear Information System (INIS)

    Vingiani, S.; Adamo, P.; Giordano, S.

    2004-01-01

    The accumulation ability of the major elements sulphur, nitrogen and carbon by the moss Sphagnum capillifolium (Ehrh.) Hedw. and the lichen Pseudevernia furfuracea (L.) Zopf exposed in bags in Naples urban area,was investigated. Bags were exposed at the beginning of July 1999 and gathered in two subsequent moments: at the end of the dry season (after 10 weeks of exposure) and during the wet season (after 17 weeks of exposure), to include the effects of rainy conditions. Sulphur and N content of the lichen increased all over the exposure period, while the level of C did not change significantly either after 10 or 17 weeks of exposition. For the moss the S accumulation was limited to the dry period of exposure, whereas N and C content decreased with exposure. Results, in contrast with those obtained in a previous study on trace elements bioaccumulation [Adamo et al., Environmental Pollution, (2003) 122, 91-103], suggest that accumulation of gaseous pollutants is strongly influenced by biomonitor vitality and that lichen bags are a more reliable and effective tool for monitoring S, N and C atmospheric depositions in urban areas compared to moss bags, because of greater lichen resistance to dry and stressing conditions of urban environment. - The lichen Pseudevernia furfuracea is more effective than the moss Sphagnum capillifolium as S and N pollutants biomonitor

  1. Oxidation kinetics and mechanisms of four-direction carbon/carbon composites and their components in carbon dioxide at high temperature

    International Nuclear Information System (INIS)

    Qin, Fei; Peng, Li-na; He, Guo-qiang; Li, Jiang

    2013-01-01

    Highlights: •Four-direction C/C composite was fabricated using carbon fibres and coal tar pitches. •Large-sized bulk matrix was prepared using same process as matrix of C/C composites. •A and E a of C/C, bulk matrix and fibres in CO 2 were determined, respectively. •Pressure exponent n was 0.62 in C/C–CO 2 . -- Abstract: Thermogravimetric analysis and scanning electron microscopy were used to study the oxidation kinetics of four-direction carbon/carbon composites and their components (fibres and matrix) in a CO 2 atmosphere at high temperature. The ablation processes were restricted to reaction-limited oxidation. The mass loss rate was estimated for the four-direction carbon/carbon composites and their components within the temperature of range of 600–1400 °C. The pressure exponent for the reaction of carbon/carbon composites and CO 2 was 0.62, and the pre-exponential factor and activation energy for the reactions of CO 2 and the carbon/carbon composites, carbon fibres and matrix were determined, respectively

  2. iScreen: Image-Based High-Content RNAi Screening Analysis Tools.

    Science.gov (United States)

    Zhong, Rui; Dong, Xiaonan; Levine, Beth; Xie, Yang; Xiao, Guanghua

    2015-09-01

    High-throughput RNA interference (RNAi) screening has opened up a path to investigating functional genomics in a genome-wide pattern. However, such studies are often restricted to assays that have a single readout format. Recently, advanced image technologies have been coupled with high-throughput RNAi screening to develop high-content screening, in which one or more cell image(s), instead of a single readout, were generated from each well. This image-based high-content screening technology has led to genome-wide functional annotation in a wider spectrum of biological research studies, as well as in drug and target discovery, so that complex cellular phenotypes can be measured in a multiparametric format. Despite these advances, data analysis and visualization tools are still largely lacking for these types of experiments. Therefore, we developed iScreen (image-Based High-content RNAi Screening Analysis Tool), an R package for the statistical modeling and visualization of image-based high-content RNAi screening. Two case studies were used to demonstrate the capability and efficiency of the iScreen package. iScreen is available for download on CRAN (http://cran.cnr.berkeley.edu/web/packages/iScreen/index.html). The user manual is also available as a supplementary document. © 2014 Society for Laboratory Automation and Screening.

  3. A deep learning and novelty detection framework for rapid phenotyping in high-content screening

    Science.gov (United States)

    Sommer, Christoph; Hoefler, Rudolf; Samwer, Matthias; Gerlich, Daniel W.

    2017-01-01

    Supervised machine learning is a powerful and widely used method for analyzing high-content screening data. Despite its accuracy, efficiency, and versatility, supervised machine learning has drawbacks, most notably its dependence on a priori knowledge of expected phenotypes and time-consuming classifier training. We provide a solution to these limitations with CellCognition Explorer, a generic novelty detection and deep learning framework. Application to several large-scale screening data sets on nuclear and mitotic cell morphologies demonstrates that CellCognition Explorer enables discovery of rare phenotypes without user training, which has broad implications for improved assay development in high-content screening. PMID:28954863

  4. Highly efficient cobalt-doped carbon nitride polymers for solvent-free selective oxidation of cyclohexane

    Directory of Open Access Journals (Sweden)

    Yu Fu

    2017-04-01

    Full Text Available Selective oxidation of saturated hydrocarbons with molecular oxygen has been of great interest in catalysis, and the development of highly efficient catalysts for this process is a crucial challenge. A new kind of heterogeneous catalyst, cobalt-doped carbon nitride polymer (g-C3N4, was harnessed for the selective oxidation of cyclohexane. X-ray diffraction, Fourier transform infrared spectra and high resolution transmission electron microscope revealed that Co species were highly dispersed in g-C3N4 matrix and the characteristic structure of polymeric g-C3N4 can be retained after Co-doping, although Co-doping caused the incomplete polymerization to some extent. Ultraviolet–visible, Raman and X-ray photoelectron spectroscopy further proved the successful Co doping in g-C3N4 matrix as the form of Co(IIN bonds. For the selective oxidation of cyclohexane, Co-doping can markedly promote the catalytic performance of g-C3N4 catalyst due to the synergistic effect of Co species and g-C3N4 hybrid. Furthermore, the content of Co largely affected the activity of Co-doped g-C3N4 catalysts, among which the catalyst with 9.0 wt% Co content exhibited the highest yield (9.0% of cyclohexanone and cyclohexanol, as well as a high stability. Meanwhile, the reaction mechanism over Co-doped g-C3N4 catalysts was elaborated. Keywords: Selective oxidation of cyclohexane, Oxygen oxidant, Carbon nitride, Co-doping

  5. Abiotic and biotic determinants of leaf carbon exchange capacity from tropical to high boreal biomes

    Science.gov (United States)

    Smith, N. G.; Dukes, J. S.

    2016-12-01

    Photosynthesis and respiration on land represent the two largest fluxes of carbon dioxide between the atmosphere and the Earth's surface. As such, the Earth System Models that are used to project climate change are high sensitive to these processes. Studies have found that much of this uncertainty is due to the formulation and parameterization of plant photosynthetic and respiratory capacity. Here, we quantified the abiotic and biotic factors that determine photosynthetic and respiratory capacity at large spatial scales. Specifically, we measured the maximum rate of Rubisco carboxylation (Vcmax), the maximum rate of Ribulose-1,5-bisphosphate regeneration (Jmax), and leaf dark respiration (Rd) in >600 individuals of 98 plant species from the tropical to high boreal biomes of Northern and Central America. We also measured a bevy of covariates including plant functional type, leaf nitrogen content, short- and long-term climate, leaf water potential, plant size, and leaf mass per area. We found that plant functional type and leaf nitrogen content were the primary determinants of Vcmax, Jmax, and Rd. Mean annual temperature and mean annual precipitation were not significant predictors of these rates. However, short-term climatic variables, specifically soil moisture and air temperature over the previous 25 days, were significant predictors and indicated that heat and soil moisture deficits combine to reduce photosynthetic capacity and increase respiratory capacity. Finally, these data were used as a model benchmarking tool for the Community Land Model version 4.5 (CLM 4.5). The benchmarking analyses determined errors in the leaf nitrogen allocation scheme of CLM 4.5. Under high leaf nitrogen levels within a plant type the model overestimated Vcmax and Jmax. This result suggested that plants were altering their nitrogen allocation patterns when leaf nitrogen levels were high, an effect that was not being captured by the model. These data, taken with models in mind

  6. High methanol oxidation activity of electrocatalysts supported by directly grown nitrogen-containing carbon nanotubes on carbon cloth

    International Nuclear Information System (INIS)

    Wang, C.-H.; Shih, H.-C.; Tsai, Y.-T.; Du, H.-Y.; Chen, L.-C.; Chen, K.-H.

    2006-01-01

    The microstructure and electrochemical activity of the Pt-Ru supported by nitrogen-containing carbon nanotubes (CN x NTs) directly grown on the carbon cloth have been investigated. The CN x NTs directly grown on the carbon cloth (CN x NTs-carbon cloth composite electrode) were synthesized using microwave-plasma-enhanced chemical vapour deposition first and then use as the template to support the Pt-Ru nanoclusters subsequently sputtered on. The ferricyanide/ferrocyanide redox reaction in cyclic voltammetry (CV) measurements showed a faster electron transfer on the CN x NTs-carbon cloth composite electrode than the one with carbon cloth alone. Comparing their methanol oxidation abilities, it is found that the Pt-Ru nanoclusters supported by the CN x NTs-carbon cloth composite electrode have considerably higher electrocatalytic activity than the carbon cloth counterpart. This result suggests high performance of the CN x NTs-carbon cloth composite electrode, and demonstrates its suitability for direct methanol fuel cell applications

  7. High methanol oxidation activity of electrocatalysts supported by directly grown nitrogen-containing carbon nanotubes on carbon cloth

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.-H. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Shih, H.-C. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Institue of Materials Science and Nano Technology, Chinese Culture University, Taipei, Taiwan (China); Tsai, Y.-T. [Institue of Materials Science and Nano Technology, Chinese Culture University, Taipei, Taiwan (China); Du, H.-Y. [Institue of Materials Science and Nano Technology, Chinese Culture University, Taipei, Taiwan (China); Chen, L.-C. [Center for Condensed Matter Sciences, National Taiwan University, Taipei, Taiwan (China); Chen, K.-H. [Center for Condensed Matter Sciences, National Taiwan University, Taipei, Taiwan (China) and Institue of Atomic and Molecular Science, Academia Sinica, Taipei, Taiwan (China)]. E-mail: chenkh@pub.iams.sinica.edu.tw

    2006-12-01

    The microstructure and electrochemical activity of the Pt-Ru supported by nitrogen-containing carbon nanotubes (CN {sub x} NTs) directly grown on the carbon cloth have been investigated. The CN {sub x} NTs directly grown on the carbon cloth (CN {sub x} NTs-carbon cloth composite electrode) were synthesized using microwave-plasma-enhanced chemical vapour deposition first and then use as the template to support the Pt-Ru nanoclusters subsequently sputtered on. The ferricyanide/ferrocyanide redox reaction in cyclic voltammetry (CV) measurements showed a faster electron transfer on the CN {sub x} NTs-carbon cloth composite electrode than the one with carbon cloth alone. Comparing their methanol oxidation abilities, it is found that the Pt-Ru nanoclusters supported by the CN {sub x} NTs-carbon cloth composite electrode have considerably higher electrocatalytic activity than the carbon cloth counterpart. This result suggests high performance of the CN {sub x} NTs-carbon cloth composite electrode, and demonstrates its suitability for direct methanol fuel cell applications.

  8. Lightweight, Ultra-High-Temperature, CMC-Lined Carbon/Carbon Structures

    Science.gov (United States)</