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Optical properties of vertically aligned graphene sheets

MRS ADVANcES 2017年第2期2卷 77-82页

作者： Yamada, Takatoshi Hisa, Makoto Hasegawa, Masataka Natl Inst Adv Ind Sci & Technol 1-1-1 Higashi Tsukuba Ibaraki 3058565 Japan Technol Res Assoc Single Wall Carbon Nanotube TAS 1-1-1 Higashi Tsukuba Ibaraki 3058565 Japan

We have developed deposition of vertically aligned graphene sheets on cu foils by surface wave microwave plasma cVD and the transfer from cu foil to quartz substrate to evaluate optical reflectances and transmittances of the inherent vertical aligned phene sheets. Both reflectance and transmittance spectra are almost independent of incident angles in the range between 300 and 800nm. The reflectance is lower than 0.067%, which is lower than those of the commercial black alumite plate. The transmittances are less than the detection limit of the system. It is considered that the obtained low reflectance is attributed to the unique structure of the vertically aligned graphene sheets.

关键词： chemical vapor deposition (cVD) (deposition) optical properties c

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Diesel consumption and cO2 Emissions in Agricultural crops： An Estimation Model and a Forestry-Based Neutralization Proposal

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Journal of Agricultural Science and Technology(B) 2017年第1期7卷 34-48页

作者： Luiz carlos Sérvulo de Aquino Brunna Simōes Ungarelli Guilherme Amatuzzi Teixeira Marcos Auré1io Vasconcelos de Freitas Aida Inirida Ortega Acosta International Virtual Institute for Global Climate Change (1VIG) Coordination of Research and Engineering Postgraduation(COPPE) Federal University of Rio de Janeiro (UFR I) RI 21941-485 Brazil Alcaldia de Bogotá Secretarla Distrital de Ambiente Bogotá 110231324 Colémbia

This research presented a mathematical model to calculate the consumption of diesel oil and the respective emissions of cO2from 41 agricultural crops （38 permanent and 3 temporary） in Brazil. It contains data obtained between 2000 and 2012, from accreditedbibliographic sources. In addition to spreadsheets containing diesel consumption, resulting from the analysis of the productive processes,this research presents data on energy conversion and forest development used to subsidize cO2 emissions and mitigation *** for c sequestration of the atmosphere, four options of forest projects were systematized：（1） reforestation with fast growingspecies; （2） forest protection projects, with enrichment plantations; （3） implementation of agroforestry systems （1 st cycle）; and （4） urbanafforestation projects （streets and parks）. Such alternatives are in line with the proposals of the ＂sectorial plan for mitigation andadaptation to climate change for the consolidation of a low c emission in agriculture＂, of the Brazilian Agricultural Researchcorporation （EMBRAPA）. The results show that three temporary products （soybean, sugarcane and cotton） are responsible, for at least,85% of all cO2 emissions, comparatively the low consumption of diesel oil verified in the management of the 38 permanent productsstudied in this research. Therefore, in order to contribute to the reduction of the release of cO2 into the atmosphere, perennial crops andecologically rational extractivism should be more encouraged and more supported by the public authorities.

关键词： Agricultural crops, diesel consumption, cO2 emissions and c sequestration.

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Identification of chemical Form of carbon Released from SUS304 and SUS316 in Alkaline Solution under Low- oxygen condition

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MRS ADVANcES 2017年第11期2卷 597-602页

作者： Nakabayashi, Ryo Fujita, Tomonari Cent Res Inst Elect Power Ind Nucl Technol Res Lab Radiat Safety Res Ctr 2-11-1 Iwadokita Komae Tokyo 2018511 Japan

To classify the chemical form of stable carbon released from unirradiated stainless steel, which is the material used to simulate irradiated stainless steel, under highly alkaline and low-oxygen conditions, type 304 and 316 stainless-steel powders were immersed in 0.005 M NaOH solution. Gas and liquid samples were analyzed to identify the chemical form of carbon released from the stainless steel. The liquid samples were divided into unfiltered and filtered samples. In the gaseous phase, hydrocarbons such as methane and ethane were not detected. In the liquid phase, carboxylic acids (formic and acetic acids) were detected. However, the sum of the carbon concentrations of the carboxylic acids was significantly lower than the total organic carbon (TOc) concentration in the unfiltered samples. In the filtered samples, the TOc concentration was closer to the sum of the carbon concentrations than that for the unfiltered samples. In addition, the concentrations of the metallic elements (particularly Fe and cr), which are the main constituents of the stainless steels, tended to decrease upon ultrafiltration. This suggests that the sorption of carbon on metallic compounds (e.g., colloidal iron hydroxide) may have occurred.

关键词： c steel corrosion

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Noninvasive Fibrosis Scores as Prognostic Markers for Varices Needing Treatment in Advanced compensated Liver cirrhosis

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Open Journal of Gastroenterology 2017年第8期7卷 230-242页

作者： Elham Ahmed Hassan Abeer Sharaf El-Din Abd El-Rehim Zain El-Abdeen Ahmed Sayed Ahmed Mohmmed Ashmawy Emad Farah Mohamed Kholef Abeer Sabry Wael Abd-Elgwad Elsewify Department of Tropical Medicine and Gastroenterology Faculty of Medicine Assiut University Assiut Egypt Department of Internal Medicine Faculty of Medicine Assiut University Assiut Egypt Department of Clinical pathology Faculty of Medicine Aswan University Aswan Egypt Department of Internal Medicine Faculty of Medicine Helwan University Cairo Egypt Department of Internal Medicine Faculty of Medicine Aswan University Aswan Egypt

Background/purpose: Noninvasive assessment of esophageal varices (EVs), their size and bleeding stigmata may reduce endoscopic burden, cost and drawbacks. We aimed to evaluate the diagnostic performance of noninvasive fibrosis scores (AAR, APRI, FIB-4, King and VITRO scores) in predicting the presence of EVs and high risk varices needing treatment (VNT) in HcV-related cirrhosis of Egyptian patients. Methods: This prospective study included 154 HcV-related advanced compensated cirrhotic patients with no history of bleeding who underwent screening endoscopy for EVs. AAR, APRI, FIB-4, King and VITRO scores were assessed. Results: Esophageal varices were found in 120 patients (77.9%) and VNT in 92 patients (59.7%). Apart from AAR, all scores demonstrated statistically significant correlations with the presence and the size of EVs. Using area under receiver operating characteristic curve (AUc), these scores were good predictors for the presence of EVs and VNT, where VITRO score had the highest AUc (0.920 and 0.900) and accuracy (97.1% and 87%), sensitivity (75, 82.6%), specificity (100, 93.5%), PPV (100, 95%) and NPV (53.2, 78.4%) with cutoffs >1.3 and >1.8 respectively. conclusion: Noninvasive fibrosis scores can predict the presence of EVs and VNT. VITRO score was the best predictor with higher accuracy for clinical applicability than studied scores.

关键词： Esophageal Varices Hepatitis c Liver cirrhosis VITRO Score

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Effect of Pyrolysis Temperature and Feedstock Type on Agricultural Properties and Stability of Biochars

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Agricultural Sciences 2017年第9期8卷 914-933页

作者： Rafaela Feola conz Thalita F. Abbruzzini cristiano A. de Andrade Debora M. B. P. Milori carlos E. P. cerri Department of Soil Sciences University of Sao Paulo Piracicaba Brazil Department of Environmental Systems Sciences Institute of Agricultural Sciences Swiss Federal Institute of Technology Zurich Switzerland Brazilian Agricultural Research Corporation Jaguariuna Brazil Brazilian Agricultural Research Corporation Sao Carlos Brazil

Pyrolysis temperature and feedstock type used to produce biochar influence the physicochemical properties of the obtained product, which in turn display a range of results when used as soil amendment. From soil carbon (c) sequestration strategy to nutrient source, biochar is used to enhance soil properties and to improve agricultural production. However, contrasting effects are observed from biochar application to soil results from a wide range of biochar’s properties in combination with specific environmental conditions. Therefore, elucidation on the effect of pyrolysis conditions and feedstock type on biochar properties may provide basic information to the understanding of soil and biochar interactions. In this study, biochar was produced from four different agricultural organic residues: Poultry litter, sugarcane straw, rice hull and sawdust pyrolysed at final temperatures of 350°c, 450°c, 550°c and 650°c. The effect of temperature and feedstock type on the variability of physicochemical properties of biochars was evaluated through measurements of pH, electrical conductivity, cation exchange capacity, macronutrient content, proximate and elemental analyses, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analyses. Additionally, an incubation trial was carried under controlled conditions to determine the effect of biochar stability on cO2-eq emissions. Results showed that increasing pyrolysis temperature supported biochar stability regardless of feedstock, however, agricultural properties varied widely both as an effect of temperature and feedstock. Animal manure biochar showed higher potential as nutrient source rather than a c sequestration strategy. Improving the knowledge on the influence of pyrolysis temperature and feedstock type on the final properties of biochar will enable the use of better tailored materials that correspond to the expected results while considering its interactions with environmental conditions.

关键词： characterization GHG c Sequestration char Organic c

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SELEcTIVE HYDROGENATION OF 3,4-DIMETHOXYBENZOPHENONE IN LIQUID PHASE OVER PD/c cATALYST IN A SLURRY REAcTOR

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cANADIAN JOURNAL OF cHEMIcAL ENGINEERING 2014年第12期92卷 2157-2165页

作者： Tiwari, Manishkumar S. Yadav, Ganapati D. Ng, Flora T. T. Inst Chem Technol Dept Chem Engn Mumbai 400019 Maharashtra India Univ Waterloo Dept Chem Engn Waterloo ON N2L 3G1 Canada

Selective hydrogenation of benzophenone to benzhydrol is industrially relevant. In the current work, selective hydrogenation of 3,4-dimethoxybenzophenone (3,4-DMBP) to 3,4-dimethoxybenzhydrol (3,4-DMBH) was investigated over 5% w/w Pd/c and 5% w/w Pt/c as catalysts in a slurry reactor. The effects of hydrogen partial pressure (0.2-1MPa), catalyst loading (2.0x10(-4) to 8.0x10(-4)g/cm(3)), initial concentration of 3,4-dimethoxybenzophenone (5.0x10(-6) to 1.5x10(-4)mol/cm(3)) and temperature (40-70 degrees c) on rate of reaction and selectivity were studied. Effect of solvent such as methanol, ethanol, 2-propanol and tetrahydrofuran (THF) was also investigated. 5% w/w Pd/c was the better catalyst with THF as the best solvent, which gave 100 % conversion and 80 % selectivity in 1h for 0.5MPa hydrogen pressure at 60 degrees c. The Langmuir-Hinshelwood-Hougen-Watson model was fitted. The intrinsic kinetics and mechanism of hydrogenation were established.

关键词： catalytic hydrogenation 3 4-Dimethoxybenzopheone Pd c 3 4-Dimethoxybenzhydrol kinetics

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Synthesis and characterization of novel activated carbon from Medlar seed for chromium removal: Experimental analysis and modeling with artificial neural network and support vector regression

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Resource-Efficient Technologies 2017年第3期3卷 236-248页

作者： Mostafa Solgi Tahereh Najib Shahyar Ahmadnejad Bahram Nasernejad Chemical Engineering Department Babol Noshirvani University of Technology P.O. Box 484 *** Babol Iran Chemical Engineering Department Amirkabir University of Technology (Tehran Polytechnic) P.O. Box 15875-4413 Tehran Iran Electrical Engineering Department Babol Noshirvani University of Technology P.O. Box 15875-4413 Babol Iran

In this study, for the first time the activated carbon has been produced from medlar seed (Mespilus germanica) via chemical activation with KOH. The carbonization process was carried out at different temperatures of 450, 550, 650 and 750 °c. The Nitrogen adsorption-desorption, Fourier transform infrared spectroscopy (FTIR) and Field Emission Scanning Electron Microscope (FESEM) analyses were carried out on the adsorbents. The effect of operating parameters, such as pH, initial concentration of cr(VI), adsorbent dosage and contact time were investigated. The experimental data showed better agreement with the Langmuir model and the maximum adsorption capacity was evaluated to be 200 mg/g. Kinetic studies indicated that the adsorption process follows the pseudo second-order model and the chemical reaction is the rate-limiting step. Thermodynamic parameters showed that the adsorption process could be considered a spontaneous (ΔG < 0), endothermic (ΔH > 0) process which leads to an increase in entropy (ΔS > 0). The application of support vector machine combined with genetic algorithm (SVM-GA) and artificial neural network (ANN) was investigated to predict the percentage of chromium removal from aqueous solution using synthesized activated carbon. The comparison of correlation coefficient (R 2 ) related to ANN and the SVR-GA models with experimental data proved that both models were able to predict the percentage of chromium removal, by synthetic activated carbon while the SVR-GA model prediction was more accurate.

关键词： Activated carbon chromium removal Medlar seed Artificial neural network Support vector regression qe (mg/g) adsorption capacity at equilibrium time qe,cal (mg/g) theoretical equilibrium adsorption capacity k1 (1/min) pseudo-first order adsorption rate constant k2 (g/mg min) pseudo-second order adsorption rate constant kid (g/mg min) intra-particle diffusion rate constant c constant indicating thickness of the boundary lay qmax (mg/g) maximum adsorption capacity B (L/g) Langmuir isotherm constant n adsorption intensity KF (mg/g) Freundlich isotherm constant ΔS o (J/mol K) standard entropy change ΔGo (kJ/mol) Gibbs free energy change ΔHo (kJ/mol) standard enthalpy change R (j/mol K) universal gas constant T (K) temperature kd (ml/g) distribution coefficient Δq (%) normalized standard deviation

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颗粒尺寸、挤压和时效时间对Sic颗粒增强Al-cu-Mg基复合材料微观结构及硬度的影响

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粉末冶金材料科学与工程 2017年第1期22卷 26-32页

作者：沈茹娟王德高郭柏松宋旼中南大学深圳研究院深圳518057 中南大学粉末冶金国家重点实验室长沙410083

研究Si c颗粒尺寸、挤压和时效时间对粉末冶金法制备的Si c颗粒增强Al-cu-Mg基复合材料微观结构及硬度的影响。研究表明,挤压对复合材料的微观结构和硬度有重要影响,能够极大促进增强体在Al基体中的均匀分布和复合材料的致密化。挤压后... 详细信息

研究Si c颗粒尺寸、挤压和时效时间对粉末冶金法制备的Si c颗粒增强Al-cu-Mg基复合材料微观结构及硬度的影响。研究表明,挤压对复合材料的微观结构和硬度有重要影响,能够极大促进增强体在Al基体中的均匀分布和复合材料的致密化。挤压后的复合材料残留微孔减少,密度和硬度均得到显著提高。时效时间和Si c尺寸对复合材料中析出相的数量及尺寸有显著影响。采用较小尺寸的Si c作为增强体时,随时效时间延长,析出相在基体中均匀析出,没有明显长大,在时效12 h内没有出现峰时效。然而,采用较大尺寸的Si c作为增强体时,随时效时间延长,基体中的析出相不是很均匀,并有部分发生明显粗化,在同样的时效时间范围内出现了峰时效。

关键词： Al基复合材料 Si c 颗粒尺寸颗粒分布时效时间硬度

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Hardness of Pillared-Graphene Nanostructures via Indentation Simulation

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MRS ADVANcES 2017年第1期2卷 45-50页

作者： Sasaki, R. Shintani, K. Univ Electrocommun Dept Mech Engn & Intelligent Syst 1-5-1 Chofugaoka Chofu Tokyo 1828585 Japan

Pillared-graphene is one of nanocarbon hybrids. It consists of graphene sheets and carbon nanotubes (cNTs);the latter are bonded vertically to the former. In order to investigate the hardness of pillared-graphene, indentation simulations are performed using a molecular dynamics method. It is revealed that the hardness of pillared-graphene increases with increasing the diameter of the cNTs, whereas it decreases with increasing the distance between cNTs or temperature. Such tendencies can be understood by considering the deformations of graphene and cNTs individually.

关键词： c nano-indentation hardness

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Recent advances in guest effects on spin-crossover behavior in Hofmann-type metal-organic frameworks

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coordination chemistry Reviews 2017年 335卷 28-43页

作者： Zhao-Ping Ni Jun-Liang Liu Md. Najbul Hoque Wei Liu Jin-Yan Li Yan-cong chen Ming-Liang Tong Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education School of Chemistry Sun Yat-Sen University Guangzhou 510275 PR China

The incorporation of spin-crossover (ScO) properties into metal-organic frameworks (MOFs) is an appealing subclass of multifunctional MOFs with potential applications in molecular sensing. This review focuses on the design of ScO Hofmann-type MOFs, with emphasis on the guest effect on their ScO properties. The influences of guest size, dielectric constant, π ⋯ π interaction, hydrogen bonding interactions, weak X⋯M′ covalent bonding, and chemical reaction on the ScO properties of Hofmann-type MOFs are systematically explored. Further enhancements of sensing properties are also illustrated.

关键词： azpy trans -4,4′-azopyridine pz pyrazine py pyridine 3-Fpy 3-fluoropyridine 3-NH 2 py 3-aninopyridine phpy 4-phenylpyridine bpac bis(4-pyridyl)acetylene bpeben 1,4-bis(4-pyridylethynyl)-benzene dpsme 4,4′-di(pyridylthio)methane bipytz 3,6-bis(4-pyridyl)-1,2,4,5-tetrazine bpmp 1,4-bis(pyridin-4-ylmethyl)piperazine bpp 2,5-bis(pyrid-4-yl)pyridine dpb 1,4-di(pyridin-4-yl)benzene bz benzene Ac acetone Acn acetonitrile IBz iodobenzene MeOH methanol EtOH ethanol Tol toluene fur furan pyr pyrrole thio thiophene Mal maleic anhydride HMal Maleic acid bpbd 2,3-bis(4′-pyridyl)-2,3-butanediol n -PrOH 1-propanol c 6 H 12 cyclohexane s -BuOH sec -butanol i -BuOH isobutanol i -PrOH isopropanol naph naphthalene anth anthracene TclBz 1,2,4-trichlorobenzene clBz chlorobenzene BrBz bromobenzene dpe 1,2-di(4-pyridyl)ethylene dpa 1,2-di(4-pyridyl)ethane bbz bibenzyl stb stilbene bpb bis(4-pyridyl)butadiyne bipydz 3,6-bis(4-pyridyl)-1,2-diazine c 7 H 8 2,5-norbornadiene Spin-crossover Host-guest interaction Hofmann-type Metal-organic frameworks

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