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101.
Ben Williams Xiaowei Wang Hongrui Ma Roger Cracknell David Richardson Stan Wallace 《Combustion and Flame》2010,157(10):1866-1878
A study of in-cylinder fuel-air mixing distributions in a firing gasoline-direct-injection engine is reported using planar laser-induced fluorescence (PLIF) imaging. A multi-component fuel synthesised from three pairs of components chosen to simulate light, medium and heavy fractions was seeded with one of three tracers, each chosen to co-evaporate with and thus follow one of the fractions, in order to account for differential volatility of such components in typical gasoline fuels. In order to make quantitative measurements of fuel-air ratio from PLIF images, initial calibration was by recording PLIF images of homogeneous fuel-air mixtures under similar conditions of in-cylinder temperature and pressure using a re-circulation loop and a motored engine. This calibration method was found to be affected by two significant factors. Firstly, calibration was affected by variation of signal collection efficiency arising from build-up of absorbing deposits on the windows during firing cycles, which are not present under motored conditions. Secondly, the effects of residual exhaust gas present in the firing engine were not accounted for using a calibration loop with a motored engine.In order to account for these factors a novel method of PLIF calibration is presented whereby ‘bookend’ calibration measurements for each tracer separately are performed under firing conditions, utilising injection into a large upstream heated plenum to promote the formation of homogeneous in-cylinder mixtures. These calibration datasets contain sufficient information to not only characterise the quantum efficiency of each tracer during a typical engine cycle, but also monitor imaging efficiency, and, importantly, account for the impact of exhaust gas residuals (EGR). By use of this method EGR is identified as a significant factor in quantitative PLIF for fuel mixing diagnostics in firing engines.The effects of cyclic variation in fuel concentration on burn rate are analysed for different fuel injection strategies. Finally, mixture distributions for late injection obtained using quantitative PLIF are compared to predictions of computational fluid dynamics calculations. 相似文献
102.
Obtaining accurate anthropometric body segment parameters in a fast and reliable manner is an essential step in biomechanical analysis of human motion. With advance of computer vision, and reduction in cost of electronic components, building a customized computer-vision based measurement device becomes possible. In the paper a novel structured light pattern for 3D structured light scanner is proposed. During development, accuracy and robustness of the proposed system were tested on artificial objects with known surface configurations, after which measurements were performed on human subjects. Simultaneous measurements with standard structured light pattern were achieved and obtained results compared. Volumetric parameters of both artificial object and human body segment obtained by 3D scanning were compared to the immersion method and were found to be in a good agreement and were used for segment mass estimation. Obtained results are presented and analyzed, and conclusions about system performance with possible improvements are discussed. 相似文献
103.
Stan Majoor 《Journal of Housing and the Built Environment》2006,21(1):15-32
The implementation of concepts of multiple land use seems to be relevant in the context of large-scale urban projects, which are now predominately monofunctional. However, current governance settings at these projects seem to be unreceptive to this new planning concept. Our in-depth case study of the South Axis project in Amsterdam embraces an actor-centred institutional perspective and seeks to understand how more receptive conditions for norm alignment between key actors can be attained. We reconstruct the introduction of quite radical concepts of multiple land use in this project, which started as an office-development proposal. The implementation was severely hampered by the fact that ambitions were formed in a rather introvert local government – business setting. Only in the last stage, with the adoption of a more extrovert mode of governance that included a variety of national government departments, were more receptive conditions for multiple land use created. 相似文献
104.
Mohammad Alrosan Thuan-Chew Tan Azhar Mat Easa Sana Gammoh Stan Kubow Muhammad H. Alu'datt 《International Journal of Food Science & Technology》2022,57(4):2039-2050
There has been a growing interest in plant proteins due to their beneficial health effects, low cost and variety of applications in food industries. The low solubility of lentil proteins (LPs) is one of the significant factors that limit their use in food applications. Quinoa proteins (QPs), which have high water solubility, were combined with LPs at pH 12 to generate LP-QP complexes to generate pH-based soluble protein compounds. The LP-QP complexes demonstrated a large surface charge with an increase solubilisation of the protein complexes by more than 85%, together with resistance to protein aggregation. The combination of LPs to QPs led to a significant increase (P < 0.05) in unique tertiary and secondary protein structures as determined by the protein–protein interaction (PPI) technique involving pH recycling. Interactions between LPs and QPs affected the surface morphology of the protein complexes formed. Electrostatic interactions, hydrophobic forces and hydrogen bonding were indicated to play key roles in the PPIs. The capacity of pH cycling to illustrate the above protein interactions shows that this is a robust approach for assessing the emulsion and foaming properties of food proteins. 相似文献
105.
Gadolinium iron garnet was obtained from two different precursors, homogenized in isopropyl alcohol and in an aqueous environment with a fixed pH. In the first case, it was a mixture of goethite (FeO(OH)) and gadolinium oxide (Gd2O3); in the second, a mixture of GdIP (GdFeO3) and α-Fe2O3. Conditions of homogenization in the aqueous environment were selected based on the zeta (ξ) potential measurements as the function of pH. DSC measurements of the output powder mixtures allowed the identification of the effects observed during the temperature rise. In the case of the material obtained from a mixture of goethite (FeO(OH)) and gadolinium oxide, with the increasing temperature, we observe three effects, the first of which corresponds to the phase transformation of goethite into α-Fe2O3, the second corresponds to the reaction of gadolinium iron perovskite (GdIP) formation, and the third to the reaction in which a gadolinium iron garnet (GdIG) is formed. However, in the case of heat treatment of the mixture of GdIP and α-Fe2O3, we only observe the effect responsible for a solid state reaction leading to the formation of gadolinium iron garnet. Dilatometric measurements allowed to determine the changes in linear dimensions at various stages of reaction sintering. The resulting materials were sintered at temperatures of 1200, 1300, and 1400 °C. In the case of the material obtained from a mixture of perovskite and iron (III) oxide, already at the temperature of 1300 °C, a density has been obtained at around 95% of the theoretical density, and the temperature of 1400 °C allowed achieving a density of 97% of the theoretical density. Whereas, for the material obtained from a mixture of goethite (FeO(OH)) and gadolinium oxide, a density above 95% of theoretical density was achieved only at 1400 °C. 相似文献
106.
Corneliu Sergiu Stan Ioan Rosca Daniel Sutiman Marius Sebastian Secula 《中国稀土学报(英文版)》2012,30(5):401-407
The preparation of two highly luminescent europium(III) and terbium(III) complexes with succinimide(SI) and N-hydroxysuccinimide(NHSI) were reported,which were further investigated through elemental chemical analysis,thermal analysis,FT-IR,powder X-ray diffraction,SEM and fluorescence spectroscopy.Data collected through these analysis revealed the formation of the Eu(III) and Tb(III) complexes with the above mentioned ligands at a metal to ligand(M:L) molar ratio of 1:3.Interesting conclusions regarding the efficient sensitization through the coordination site of the lanthanide luminescent centers were retained from the photoluminescent spectra investigation.Strong luminescence emission was observed in case of Eu(III)-SI and Tb(III)-NHSI complexes while the corresponding Eu(III)-NHSI and Tb(III)-SI complexes exhibited no photo luminescent properties.Newly obtained luminescent lanthanide complexes may be of particular interest for various applications in optoelectronics. 相似文献
107.
I.O. Usov P.N. Arendt S.R. Foltyn L. Stan R.F. DePaula T.G. Holesinger 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(11-12):2046-2050
One of the crucial steps in the second generation high temperature superconducting wire program was development of the buffer-layer architecture. The architecture designed at the Superconductivity Technology Center at Los Alamos National Laboratory consists of several oxide layers wherein each layer plays a specific role, namely: nucleation layer, diffusion barrier, biaxially textured template, and intermediate layer providing a suitable lattice match to the superconducting Y1Ba2Cu3O7 (YBCO) compound. This report demonstrates how a wide range of ion beam analysis techniques (SIMS, RBS, channeling, PIXE, PIGE, NRA and ERD) was employed for analysis of each buffer layer and the YBCO film. These results assisted in understanding of a variety of physical processes occurring during the buffer layer fabrication and helped to optimize the buffer-layer architecture as a whole. 相似文献
108.
S. Staněk R. Šárová E. Nejedlá S. Šlosárková O. Doležal 《Journal of dairy science》2018,101(1):830-839
Disbudding is a routine practice in many dairy herds due to the effort to decrease the risk of injuries. Although the disbudding practice is regulated, it can vary among farms. The variation may be caused by many factors, such as herd size or type of breed, but also by farmers' perception of pain caused by disbudding. Hence, the aim of this study was to specify the disbudding practice on dairy farms in the Czech Republic and to assess these practices, including the use of pain mitigation medication, by breed, herd size, and sex of the disbudded calves. We analyzed data from 106 Czech dairy farms, which were collected by a trained interviewer at dairy meetings in 2014–2015. The farmers answered questions regarding the farm's basic characteristics, disbudding practice, and his/her attitude to the pain caused by disbudding. To test the influence of breed, herd size, and sex of disbudded calves on different variables, logistic regression models were used. Disbudding was performed in 92.5% of the surveyed farms; 63.3% of dairy calves were disbudded before 4 wk of age, and Czech Fleckvieh calves were 2.8 times more likely to be disbudded before 4 wk of age than Holstein calves. The hot-iron method was the most used method (69.4%). Calves were 4.5 times more likely to be disbudded by hot iron in herds where both heifers and bulls were disbudded than in herds where only heifers were disbudded. Most (>90%) surveyed farms did not use any pre- or post-procedure medication to mitigate the pain caused by disbudding. The disbudding procedure was performed mainly by farm personnel (94.9%), who were trained by a veterinarian or veterinary technician (46.9%) or by other farm personnel (37.8%) or were not trained (15.3%). Two-thirds of farmers observed behavioral changes in calves after disbudding. Most farmers estimated the pain caused by disbudding to be mild or moderate (20.4 or 45.9%, respectively) and 15.3% of farmers estimated it to be severe. Almost a quarter of interviewed farmers were unable to assess the duration of pain, 39.8% farmers estimated that the pain lasts only several minutes, and 20.4% estimated that the pain lasts up to 6 h. We detected a tendency that farmers of larger herds estimated pain duration to be shorter (odds ratio = 1.2). To improve calves' welfare, training is needed in disbudding practice, focusing on the advantage of pain mitigation. 相似文献
109.
Stan Chiriţă 《热应力杂志》2018,41(5):608-626
This article deals with some high-order approximations of the three-phase-lag heat transfer model aiming, at first, to identify the restrictions that make them well-posed consistence. Consequently, a first result about the uniqueness and continuous dependence of the solutions with respect to the given initial data and to the supply term is established for the related initial boundary value problems. Subsequently, to provide a more comprehensive analysis of the model, some further spatial decay results are established, this time conveniently relaxing the hypotheses about the delay times and the thermal conductivities. More precisely, a theorem of influence domain is proved for the wave propagating models and an exponential decaying estimate of Saint-Venant type is established for the diffusive models. 相似文献
110.