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排序方式: 共有1061条查询结果,搜索用时 10 毫秒
91.
Gabriele Landucci Benedetta NucciLuigi Pelagagge Cristiano Nicolella 《Journal of food engineering》2011,105(1):105-111
This work presents a methodology for the assessment of hazards due to the formation of flammable mixtures in edible oil refineries, with particular focus on storage tanks. Safety issues in these plants are due to the presence of residual volatile flammable solvents deriving from the extraction processes, which may accumulate in the storage tanks and generate flammable vapour mixtures. The methodology, based on the application of a thermodynamic model for the estimation of vapour phase composition in oil storage tanks as a function of operating conditions (i.e. temperature and residual solvent content), allows the identification of potential hazards due to formation of flammable mixtures inside the tanks. The model was first validated using available experimental data and then extended to case-studies representative of state-of-the-art industrial storage applications. The results of the case-studies were then used to calculate specific hazard indexes, providing a quick tool for preliminary assessment of hazards due to the formation of flammable mixtures in edible oil storage plants. 相似文献
92.
A novel 3D homogenized FE limit analysis software is proposed for the fragility curve evaluation of entire existing masonry churches. The approach is a two-step one. In the first phase homogenized masonry strength domains are obtained using a simplified kinematic procedure applied on a three-leaf unitary cell. In the second phase, homogenized domains are implemented at a structural level on a plate and cell kinematic FE software. The procedure is tested on two real scale existing churches located in Italy and compared to results provided by means of a conventional elastic approach performed by means of a standard commercial software. The global behavior at failure and the overall strength of the buildings are assessed through Monte Carlo simulations varying both masonry mechanical properties and direction of the equivalent seismic load. 相似文献
93.
In this study, delamination of a perfectly-adherent FRP reinforcement from a masonry pillar is investigated by means of a fully three-dimensional finite element model. It is shown that the width of the FRP reinforcement governs the propagation of damage through the brick bulk starting from the anchorage of the strip, and influences significantly the overall response in terms of peak strength, ductility and fracture energy. The resulting failure mechanisms are specified. A critical comparison with formulae provided by Italian design code is also provided, for which mechanically-based improvements are suggested, taking into account three-dimensional effects. 相似文献
94.
An optical strain measurement system for asphalt mixtures 总被引:1,自引:1,他引:0
Bjorn Birgisson Antonio Montepara Elena Romeo Riccardo Roncella Reynaldo Roque Gabriele Tebaldi 《Materials and Structures》2009,42(4):427-441
Knowledge of the conditions governing the initiation and propagation of cracks in hot mix asphalt (HMA) mixtures is a prerequisite
for a comprehensive understanding of HMA cracking mechanisms. Traditional strain measurement sensors have proved to be not
completely adequate in the sense that they do not provide pointwise measurements, thus not pinpointing the location of crack
initiation, and not accounting for non-uniform strain distributions. This paper presents a digital image correlation (DIC)
system for non-contact and full strain field measurements, conceived for the purpose of investigating the cracking behavior
of HMA mixtures. The whole system was developed so as to account for the special nature of typical HMA testing configurations.
An image matching technique (least squares matching) was employed for providing matches with sub-pixel accuracy. The performance
of the method was investigated by several tests. The DIC system was shown to overcome the shortcomings of traditional on-specimen
strain measurement devices achieving satisfactory accuracy compared to strain gauges. 相似文献
95.
96.
97.
Herschbach Peter; Duran Gabriele; Waadt Sabine; Zettler Angela; Amm Christoph; Marten-Mittag Birgit; Strian Friedrich 《Canadian Metallurgical Quarterly》1997,16(2):171
This study reports the psychometric properties of a 45-item diabetes-specific questionnaire, the Questionnaire on Stress in Patients with Diabetes—Revised (QSD-R), a modified and shortened version of the QSD (G. Duran et al; see record 1996-18805-001). The QSD-R was filled out by 1,930 individuals with insulin-dependent diabetes mellitus and noninsulin-dependent diabetes mellitus. Eight consistent scales were identified (values of Cronbach's α: .69–.81). The test-retest reliability for the total score after a 5-week interval was rtt?=?.63. The results provide evidence for the reliability and validity of this instrument. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
98.
Lido Calorini Anna Fallani Donatella Tombaccini Emanuela Barletta Gabriele Mugnai Maria F. Di Renzo Paolo M. Comoglio Salvatore Ruggieri 《Lipids》1989,24(8):685-690
To determine whether a metastatic phenotype may be corelated with a characteristic lipid pattern, we compared the lipid composition
of low metastasizing Balb/c 3T3 cells transformed by the B77 strain of Rous sarcoma virus (B77-3T3 cells) with that of a subclone
isolated by growth in 0.6% agar, the B77-AA6 cells, which exhibit a high capacity for spontaneous metastasis. B77-3T3 cells
revealed characteristics in their lipid composition common to other systems of transformed cells, i.e., an accumulation of
ether-linked lipids, a reduction of the more complex gangliosides, an increase of oleic acid (18∶1) and a decrease of arachidonic
(20∶4) and C22 polyunsaturated fatty acids in phospholipids. High metastatic B77-AA6 cells showed: a) an even more marked
decrease of complex gangliosides; b) a more pronounced increase of 18∶1 and decrease of 20∶4 and 22 polyunsaturated fatty
acids in certain phospholipid classes; and c) a higher percentage of alkyl-acyl subfractions in both phosphatidylcholine and
phosphatidylethanolamine than B77-3T3 cells.
Comparing the data for other systems of metastatic cells with those of lipid studies of spontaneously metastasizing B77-AA6
cell system leads us to conclude that the metastatic phenotype is characterized by a change in ether-linked lipids, rather
than in fatty acids. 相似文献
99.
Murari Lal Gupta Bhuvanesh Gupta Wilhelm Oppermann Gabriele Hardtmann 《应用聚合物科学杂志》2004,91(5):3127-3133
The alkaline hydrolysis of polyacrylonitrile staple fibers was investigated for evaluation as superabsorbent materials. Studies were performed to analyze the hydrolysis of fibers and the quantification of the developed functional groups, such as carboxyl and amide groups as well as changes in the nitrile content by means of Micro‐ATR. Dyeing of the samples with methylene blue was carried out to monitor the carboxyl groups formed during the hydrolysis. A gradual decrease in the nitrile groups and built up of the carboxyl and the amide groups was observed during the hydrolysis. Microscopic investigation carried out to investigate the surface structure of hydrolyzed fibers. Hydrolysis led to surface nonhomogeneity and erosion that was dependent on the hydrolysis conditions. The fibers showed good water retention behavior, making them superabsorbent materials. The dyeing showed more intense coloration in the surface region of the modified fibers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3127–3133, 2004 相似文献
100.
Gehring William J.; Gratton Gabriele; Coles Michael G.; Donchin Emanuel 《Canadian Metallurgical Quarterly》1992,18(1):198
Investigated the effects of probability information on response preparation and stimulus evaluation. Eight Ss responded with 1 hand to the target letter H and with the other to the target letter S. The target letter was surrounded by noise letters that were either the same as or different from the target letter. In 2 conditions, the targets were preceded by a warning stimulus unrelated to the target letter. In 2 other conditions, a warning letter predicted that the same letter or the opposite letter would appear as the imperative stimulus with .80 probability. Correct reactions times (RTs) were faster and error rates were lower when imperative stimuli confirmed the predictions of the warning stimulus. Probability information affected (1) the preparation of motor responses during the foreperiod, (2) the development of expectancies for a particular target letter, and (3) a process sensitive to the identities of letter stimuli but not to their locations. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献