62,280 research outputs found
On rellich’s lemma, the poincaré inequality, and friedrichs extension of an operator on complex spaces
Full text linkThis paper is mainly concerned with: (i) a generalization of the Rellich’s Lemma to a Riemann subdomain of a complex space, (ii) the Poincaré inequality, and (iii) Friedrichs extension of a Schrödinger type operator. Applications to the eigenfunction expansion problem associated to the modified Laplacian are also given
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
Full text linkThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
OPTIMAL BALANCE BETWEEN LAND DEVELOPMENT AND GROUNDWATER CONSERVATION IN AN UNCERTAIN COASTAL ENVIRONMENT
No full textSynthesis of Tung Oil Anhydride-Ester Polyol
No full textTung oil is a special biomass resource in China. Tung Oil has the characteristic to be transformed into serial derivatives for its active Conjugated double bond. Especially, tung oil anhydride-ester polyol (TOAEP) can be used as substitute of polyester polyol and/or polyether polyol in the synthesis and modification of polyurethane materials. Through esterification and transesterification, methyl-α-eleostearate-maleic anhydride adduct (MEMAA), a derivative of tung oil, was reacted with ethylene glycol and tung oil anhydride-ester polyol (TOAEP) was obtained. The optimal preparation condition are as follows: p-toluene sufonic acid is used as the catalyst, mole ratio of ethylene glycol to MEMAA is 4:1, reaction temperature is 120°C ~130°C, reaction duration is 8 h. Under the optimal preparation conditions, the yield of TOAEP is up to 88.8% and the hydroxyl value is up to 318.0 mg KOH/g. The structure of TOAEP was confirmed by Infrared spectroscopy (IR).</jats:p
Produção de biodiesel por processo não catalítico com etanol supercrítico a partir do óleo de tungue (Vernicia fordii) bruto e in situ
Full text linkTese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2015.O trabalho teve como objetivo avaliar o rendimento de biodiesel produzido a partir da transesterificação não catalítica do óleo de tungue bruto e in situ sob condições supercríticas do etanol, bem como verificar a influência das condições operacionais sobre o perfil dos ésteres etílicos de ácidos graxos (FAEE). Para executar as reações de transesterificação com etanol supercrítico foi desenvolvida uma unidade experimental multipropósito com reator batelada (500 ml) e sistema de aquisição e monitoramento da pressão, temperatura e tempo de reação. O planejamento fatorial 23 completo com ponto central foi empregado com o intuito de avaliar a influência das condições operacionais. Quando foi utilizado o óleo bruto, avaliou-se o efeito da razão molar de óleo/álcool (1/18 e 1/42), temperatura (290 oC e 330 oC) e tempo de reação (5 min e 55 min), e quando o óleo in situ (semente) foi a matéria-prima, foram avaliados a razão da massa por volume (1/10 e 1/30), temperatura (270 oC e 310 oC) e granulometria (8-10 mesh e inteira). A caracterização e quantificação dos FAEE foi realizada por cromatografia gasosa acoplada a detector de ionização em chama (GC-FID). Foram determinadas as curvas analíticas para os ésteres etílicos dos ácidos: láurico, mirístico, palmítico, palmitoleico, esteárico, oleico, linoleico, linolênico e araquidônico. As condições operacionais exerceram grande influência sobre o rendimento do biodiesel de tungue. A transesterificação a partir do óleo bruto propiciou rendimentos de até 95,7% na condição de ponto central (1/30, 310 oC e 30 min) e a análise de variância ao nível de 95% indicou que o tempo de reação não exerce influência significativa na faixa investigada. Em relação ao perfil de FAEE, o teste Tukey ao nível de 5% de probabilidade indicou diferenças significativas entre as médias. Ésteres etílicos de ácidos graxos saturados são influenciados positivamente pelo acréscimo da temperatura e tempo de reação, aumentando seus teores, enquanto que, os teores de insaturados decrescem. A transesterificação in situ do óleo de tungue proporcionou atingir rendimentos de até 94,0%. As análises estatísticas indicaram que a granulometria investigada não exerce influência sobre o rendimento e perfil de FAEE. A biomassa residual de tungue, obtida após o processo de transesterificação in situ, possui elevado valor energético, com poder calorífico superior de 8.124 kcal/kg.Abstract : The objective of this study was to evaluate the yield of biodiesel produced from non-catalytic transesterification of raw crude tung oil and in situ oil, under supercritical conditions of ethanol, as well to determine the influence of the operating conditions on the profile of ethyl esters of fatty acids (FAEE). To perform the transesterification reactions with supercritical ethanol it developed a multipurpose experimental unit with batch reactor (500 ml) and system of the acquisition and monitoring of pressure, temperature and reaction time. A 23 factorial design with central point was applied in order to evaluate the influence of operating conditions. When the crude oil was used as raw material were evaluated the molar ratio of oil/alcohol (1/18 and 1/42), temperature (290 oC and 330 oC) and reaction time (5 min and 55 min). When used in situ oil was evaluated the mass/volume ratio (1/10 and 1/30), temperature (270 ºC to 310 ºC) and particle size (8-10 mesh and whole). The characterization and quantification of esters were performed by gas chromatography coupled with a flame ionization detector employing the method of internal standardization with methyl heptadecanoate. Were determined the analytical curves for the ethyl esters of fatty acids: lauric, myristic, palmitic, palmitoleic, stearic, oleic, linoleic, linolenic and arachidonic. Operational conditions have exerted great influence on the yield of biodiesel of tung. The transesterification from crude oil afforded yields of up to 95.7% in the central point of condition (1/30, 310 ºC and 30 min) and the analysis of variance at 95% indicated that the reaction time had no influence significantly in the investigated range. Regarding the profile of FAEE, the Tukey test at 5% probability indicated significant differences between means. Ethyl esters of saturated acids are positively influenced by increased temperature and reaction time, while the content of the unsaturated decrease. The in situ transesterification of tung oil afforded achieve yields of up to 94.0%. Statistical analysis indicated that the particle size investigated had no influence on yield and FAEE profile. The residual biomass tung originated from the process of the in situ transesterification possesses high energetic value, with superior calorific power of 8,124 kcal/kg
Modeling Climate Change Impacts on Stream Temperature of Formosan Landlocked Salmon Habitat
No full textSuppression of Food Intake in the Rat by Tung Oil
No full text Tung oil has previously been found to suppress voluntary food intake when mixed with the diet. When tung oil or corn oil were fed by stomach tube to weanling and adult rats, the voluntary intake of laboratory chow was depressed by both lipids. The corn-oil fed animals readjusted their caloric intake to their prefeeding level in adults and to the level consumed by chow-only fed weanlings of the same age. However, the tung-oil fed adult animals consumed only one-half the dry food intake of the corn-oil fed animals (p < 0.001). Consequently the adult tung-oil fed animals lost significantly more (p < 0.01) of their body weight than did the corn-oil fed controls. This suggests that the mechanism of suppression of food intake by tung oil operates at some level other than taste or consistency of the diet. </jats:p
Homogenization of an interface highly oscillating between two concentric ellipses
Full text linkThe main purpose of this paper is to find the homogenized equation and the associate continuity conditions in the explicit form of a boundary-value problem in a two-dimensional domain with an interface oscillating rapidly between two concentric ellipses. This boundary-value problem originates from various problems in practical applications. By the homogenization method and following the technique presented recently by Vinh and Tung [P. C. Vinh and D. X. Tung, Mech. Res.Comm. 37 (2010), 285-288; P. C. Vinh, D. X. Tung, ASME J. Appl. Mech., 78 (2011), 041014-1; P. C. Vinh and D. X. Tung, Acta Mech. 218 (2011), 333-348], the homogenized equation and the associate continuity conditions in the explicit form are derived
- …
