Modelling soot formation in a DISI engine

In this work, the formation of soot in a Direct Injection Spark Ignition (DISI) engine is simulated using the Stochastic Reactor Model (SRM) engine code. Volume change, convective heat transfer, turbulent mixing, direct injection and flame propagation are accounted for. In order to simulate flame propagation, the cylinder is divided into an unburned, entrained and burned zone, with the rate of entrainment being governed by empirical equations but combustion modelled with chemical kinetics. The model contains a detailed chemical mechanism as well as a highly detailed soot formation model, however computation times are relatively short. The soot model provides information on the morphology and chemical composition of soot aggregates along with bulk quantities, including soot mass, number density, volume fraction and surface area. The model is first calibrated by simulating experimental data from a Gasoline Direct Injection (GDI) Spark Ignition (SI) engine. The model is then used to simulate experimental data from the literature, where the numbers, sizes and derived mass particulate emissions from a 1.83 L, 4-cylinder, 4 valve production DISI engine were examined. Experimental results from different injection and spark timings are compared with the model and the qualitative trends in aggregate size distribution and emissions match the exhaust gas measurements well. © 2010 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Experimental Investigation On The Holdup Distribution Of Oil-Water Two-Phase Flow In Horizontal Parallel Tubes

An experimental investigation was conducted to study the holdup distribution of oil and water two-phase flow in two parallel tubes with unequal tube diameter. Tests were performed using white oil (of viscosity 52 mPa s and density 860 kg/m(3)) and tap water as liquid phases at room temperature and atmospheric outlet pressure. Measurements were taken of water flow rates from 0.5 to 12.5 m(3)/h and input oil volume fractions from 3 to 94 %. Results showed that there were different flow pattern maps between the run and bypass tubes when oil-water two-phase flow is found in the parallel tubes. At low input fluid flow rates, a large deviation could be found on the average oil holdup between the bypass and the run tubes. However, with increased input oil fraction at constant water flow rate, the holdup at the bypass tube became close to that at the run tube. Furthermore, experimental data showed that there was no significant variation in flow pattern and holdup between the run and main tubes. In order to calculate the holdup in the form of segregated flow, the drift flux model has been used here.

Garci Sánchez de Badajoz y la propulsión del Cancionero General

Integran este número de la revista ponencias presentadas en Studia Hispanica Medievalia VIII : Actas de las X Jornadas Internacionales de Literatura Española Medieval, 2011, y de Homenaje al Quinto Centenario del Cancionero General de Hernando del Castillo.

Regulamentação da influência do poder econômico nas eleições

Consultoria Legislativa - Área I - Direito Constitucional, Eleitoral, Municipal, Administrativo, Processo Legislativo e Poder Judiciário.

Record of wells in the Ruskin area of Hillsborough County, FLorida

A detailed study of the geology and ground-water resources of the Ruskin area (fig. 1) was made during the period from 1950 to 1955, by the U. S. Geological Survey in cooperation with the Florida Geological Survey and the Board of County Commissioners of Hillsborough County. The results of this study are given in a report by Harry M. Peek entitled "The artesian water of the Ruskin area of Hillsborough County, Florida" and published by the Florida Geological Survey as Report of Investigations No. 21. This report contains tables of well records that were compiled from data collected during that investigation. The well-numbering system used in the tables is based on latitude and longitude. (PDF contains 88 pages.)

Tratado descriptivo do Brasil em 1587

A primeira notícia que se tem do manuscrito foi dada por Diogo Barbosa Machado no v. 2 de sua Bibliotheca Lusitana. Da obra, oferecida a D. Cristóvão de Moura, em 1 de março de 1587, foram extraídas, ao longo de mais de dois séculos, cópias mais ou menos fiéis das quais acabaram sendo suprimidas o nome do autor e tendo seu título sofrido um certo número de variações. O primeiro a tentar dar publicidade ao texto, foi Frei Mariano da Conceição Velloso, com a malograda impressão da versão intitulada Descripção geographica da America portugueza. Em 1825, a Academia Real das Sciencias de Lisboa publicou a dita obra, cumulada de erros, no v. III, pt. 1, da Collecção de Notícias ... das Nações Ultramarinas, dando-lhe o título de Noticia do Brasil, descripção verdadeira da costa d'aquelle Estado ... . Finalmente, o Visconde de Porto Seguro, com base no confronto de mais de 20 versões, conseguiu reestabelecer a integridade do texto e o mandou publicar no tomo XIV da Revista do IHGB, e em exemplares à parte, que sairam em 1851, pela Laemmert. A edição de 1879 é, no entanto, "a mais apreciada de todas as anteriores" no parecer de Rubens Borba de Moraes (p. 361). Quanto ao texto, é considerado notável, um dos mais valiosos documentos do Brasil quinhentista, com informações sobre geografia, etnografia, agricultura e desenvolvimento, principalmente da Bahia, e de incontestável apreço para o estudo das Ciências Naturais do Brasil, visto que, como observador atento, o autor descreveu ainda, de forma precisa e meticulosa, a fauna e flora brasileira

Interfaz accesible persona-robot para un brazo artículado

Desarrollo de una interfaz persona-robot para un brazo artículado portátil montado en una silla de ruedas elecétrica, destinado a personas con restricciones motoras severas.

Arctic charr (Salvelinus alpinus) in Windermere (Cumbria)

The Arctic charr of the British Isles are all non-migratory and are near their most southernmost range. Windermere is one of the few lowland lakes at southerly latitudes to contain a substantial proportion of Arctic charr. The first recorded mention of charr in Windermere was made around 1540 but it was not till the 17th century that different "sons" of charr were recognized, based on differences in their breeding behaviour. In the 1960's, the presence of two distinct populations, autumn spawners and spring spawners were discovered. In the 1980's it was shown that there were at least four races of charr in Windermere, based on genetic characteristics. Recently, the lake has changed due to inputs of phosphorus from treated sewage released into the lake resulting in eutrophication particularly in the south basin. Since the mid-1980's the numbers of charr caught in the south basin have declined.

掺镁近化学计量比LiTaO3晶体的生长及光学性能

在同成分LiTaO3熔体中掺入一定剂量的K2O,采用顶部籽晶提拉法生长掺镁近化学计量比LiTaO3晶体。对晶体分别进行光谱分析,畴结构和抗光损伤阈值的测定。结果表明：与同成分掺镁LiTaO3晶体相比较,其紫外吸收边出现明显蓝移,红外吸收峰变弱。腐蚀晶片的晶相显微镜观察结果表明：掺镁近化学剂量比晶体的畴结构是较为规则的六边形;晶体的抗光致散射能力明显提高。

Broadband near-infrared emission in Er3+-Tm3+ codoped chalcohalide glasses

The near-IR emission spectra of Er3+-Tm3+ codoped 70GeS(2)-20In(2)S(3)-10CsI chalcohalide glasses were studied with an 808 nm laser as an excitation source. A broad emission extending from 1.35 to 1.7 mu m with a FWHM of similar to 160 nm was recorded in a 0.1 mol.% Er2S3, 0.5 mol.% Tm2S3 codoped chalcohalide glass. The fluorescence decay curves of glasses were measured by monitoring the emissions of Tm3+ at 1460 nm and Er3+ at 1540 nm, and the lifetimes were obtained from the first-order exponential fit. The luminescence mechanism and the possible energy-transfer processes are discussed with respect to the energy-level diagram of Er3+ and Tm3+ ions. (C) 2008 Optical Society of America