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排序方式: 共有1623条查询结果,搜索用时 187 毫秒
71.
Patricia Perez-Fuster Maria F. Rodrigo Maria Luisa Ballestar Jaime Sanmartin 《Accident; analysis and prevention》2013
In relative terms, Spanish motorcyclists are more likely to be involved in crashes than other drivers and this tendency is constantly increasing. The objective of this study is to identify the factors that are related to being an offender in motorcycle accidents. A binary logit model is used to differentiate between offender and non-offender motorcyclists. A motorcyclist was considered to be offender when s/he had committed at least one traffic offense at the moment previous to the crash. The analysis is based on the official accident database of the Spanish general directorate of traffic (DGT) for the 2003–2008 time period. A number of explanatory variables including motorcyclist characteristics and environmental factors have been evaluated. The results suggest that inexperienced, older females, not using helmets, absent-minded and non-fatigued riders are more likely to be offenders. Moreover, riding during the night, on weekends, for leisure purposes and along roads in perfect condition, mainly on curves, predict offenses among motorcyclists. The findings of this study are expected to be useful in developing traffic policy decisions in order to improve motorcyclist safety. 相似文献
72.
A. Gonzalez del Campo P. Cañizares J. Lobato M.A. Rodrigo F.J. Fernandez 《International Journal of Hydrogen Energy》2012
In this work, the potential application of bio-hydrogen in a fuel cell was studied. To do that an activated sludge was acclimatized to an acidogenic culture producing bio-hydrogen. Once reached the steady state, several batch experiments were carried out by feeding a synthetic fruit juice industry wastewater to the acidogenic culture. The bio-hydrogen yield obtained when this synthetic fruit juice industry wastewater was fed was 1403 mol H2/mol hexose and the hydrogen percent in gas phase was 57%. In an average size fruit juice industry, this bio-hydrogen yield corresponds to a bio-hydrogen production of about 6000 mol H2/d. In the subsequent stage, a synthetic bio-hydrogen stream with the same composition of the cleaned bio-hydrogen obtained in the acidogenic fermentation was fed as fuel in a Fuel Cell, obtaining very similar power and polarization curves than that obtained when feeding pure hydrogen, differences lower than 10%. These results showed that the hydrogen stream obtained by the acidogenic fermentation could be used to produce electricity in a high temperature PEMFC. 相似文献
73.
74.
Alexandre Antunes Ribeiro Rodrigo Fernando Costa Marques Antônio Carlos Guastaldi João Sinézio de Carvalho Campos 《Journal of Materials Science》2009,44(15):4056-4061
Many techniques have been used to coat metallic substrate with bioceramics. The aim of this study was to study the physical-chemical
characteristics of polyvinylidene fluoride (α-PVDF)/hydroxyapatite (HA) composite coating, obtained by casting method, on
commercially pure titanium (α-CP Ti) substrate surface modified by laser beam irradiation. The preparation of coating was
done for mixing α-PVDF pellets shape dissolved in dimethylacetamide (DMA) with HA/DMA emulsion. The mixture was poured onto
the α-CP Ti sample and left to dry in an oven. CP Ti plates were coated with α-PVDF/HA composite film, in proportions of 100/00
and 60/40 in weight, and characterized by particle size analysis, scanning electron microscopy, energy dispersive spectroscopy
(EDS), X-ray diffractometry, thickness measurement and contact angle. Uniform coating with a small thickness variation along
the coated surface was successfully obtained. 相似文献
75.
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77.
Cassio Eduardo Lima de Paiva Jose Lulz Antunes de Oliveira e Sousa Luiz Carlos de Almeida Paulo RobertoAguiar Luiz Femando de Melo Correia Juliana Silva Watanabe Rodrigo Moreira de Carvalho Creso deFranco Peixoto Denis Palomo Paschoalin 《土木工程与建筑:英文版》2013,(8):964-972
The EFVM (Vitoria Minas Railroad) is one of the main railways in Brazil. It transports freight trains of ore, 220 wagons each. These wagons have 2 boogies of 2 axles each and 32 metric tons on metre gauge. Elastic strains were measured on a special part of this railway due to these trains. The main load to evaluate stresses and strains was a G 16 Locomotive, a C-C kind from Vale, a Brazilian Company. The measurements were obtained by dynamic deflectometer installed on a main line of this railway, near Ipatinga, a city from Minas Gerais, one of Brazil states. This track was equipped to obtain stresses under an equal repeated static load A simulation of the stresses was made under critical strain by Ferrovia 1.0 software. It was also made an evaluation of unequal results from neighbor sleepers taking in comparison two equipped parts of this railway, one with compacted ballast and no compaction to the other. The results were strain limited, avoiding breakage or damage to the studied rails. This work analyses these measurements focusing on the improvement of track quality. 相似文献
78.
Rodrigo Furtado de Carvalho Mutlu Özcan Frederico Louzada Evelyn Monteiro Marco Antonio Bottino Renata Marques de Melo 《Journal of Adhesion Science and Technology》2016,30(24):2690-2698
This study compared air-abrasion and etching regimens on adhesion of resin luting agent to zirconium dioxide. Ceramic specimens (LAVA, 3 M ESPE) (N = 16) were embedded in acrylic resin and exposed surfaces were polished. The specimens were randomly assigned into four groups (n = 12, 3 specimens for each disc): SC: Air-borne particle abrasion (30 μm aluminum oxide particles coated with silica, CoJet, 3 M ESPE); MH: Heated chemical solution (Methanol-800 mL; 37% Hydrochloric Acid-200 mL; Ferric Chloride-2 g) at 100 °C for 30 min, MHP: Primer (Metal/Zirconia Primer, Ivoclar Vivadent) + MH, P: Primer only (Metal/Zirconia Primer). Cylindrical molds (internal diameter: 0.7 mm; height: 1.5 mm) were placed on each conditioned specimen, filled with resin cement (Multilink Automix) and photo-polymerized for 60 s. After 24 h, the molds were removed and the specimens were stored in distilled water at 37 °C for six months). Microshear test was performed in a Universal Testing Machine (1 mm/min). Failures types were classified as adhesive, mixed, or cohesive. In another set of specimens (n = 2 per group) contact angle measurements were recorded. Data were analyzed statistically using Kruskal–Wallis and Dunn’s tests (α = 0.05). The surface conditioning method significantly affected the mean bond strength (MPa) (p < 0.0001): SC(18.3 ± 0.3)a < P(5.00 ± 0.07)b < MHP(4.7 ± 0.08)c < MH(0.84 ± 0.01)c. While Group SC showed mainly adhesive (58%) and mixed (41.7%) failure types, groups MH, MHP, and P presented exclusively adhesive failures. SC, MHP, and P (29–32°) showed lower contact angle than MH (78.9°). Volume loss was the highest with MHP (9.92 μl) followed by SC (9.67 μl). 相似文献
79.
80.
de Melo Henrique João Miller Isidro Julia Saez Cristina Dos Santos Elisama V. Rodrigo Manuel A. 《Journal of Applied Electrochemistry》2022,52(9):1317-1326
Journal of Applied Electrochemistry - This paper evaluates the remediation of soil spiked with lindane using a combined treatment consisting of electrokinetic soil flushing (EKSF) with air... 相似文献