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91.
The partial oxidation of methane is studied at 673–873 K over new Ru-based catalysts supported on TiO2–ZrO2 with different TiO2 content. Supports were prepared by a sol–gel method, and RuCl3 and RuNO(NO3)3 were used as ruthenium precursors to prepare the catalysts (1–2 wt% Ru). The effect of the reaction temperature on the catalytic behavior is analyzed, along with the support composition and the Ru precursor used.  相似文献   
92.
New flexible aliphatic oxazolidone‐isocyanurate networks (AISOX) are obtained by reacting a low molecular weight diisocyanate (4,4′‐methylene dicyclohexyl diisocyanate, H12MDI) and a macro‐diepoxyde (poly(ethylene glycol) diglycidyl ether, Mn = 526, PEGDGE) in different molar ratio. The curing reaction, carried out from 25 °C to 200 °C, is studied by using DSC and FTIR. The effect of the molar ratio of the two monomers on thermal and mechanical properties of AISOX resins is investigated by DSC, thermogravimetric analysis, stress?strain measurements and optical microscopy. Independently from the feed composition, it is observed that the reaction steps are: (i) partial hydrolysis of isocyanate caused by water traces, (ii) incomplete trimerization of isocyanate to give isocyanurate, and (iii) formation of oxazolidone and complete conversion of isocyanate. At the highest concentration of the soft macrodiepoxyde (PEGDGE), the AISOX resin is in the rubbery state at room temperature and shows an elastomeric behavior. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43404.  相似文献   
93.
Four fermentation products (FPs) of the lactic acid bacterium Lactobacillus plantarum ITM21B were screened for their anti-Bacillus activity in vitro and in bread-making trials. Results of the storage tests performed with loaves prepared with an FP or calcium propionate demonstrated that after 3 days at 30 degrees C, gross spoilage was evident in only the control loaves, which contained Bacillus subtilis at numbers of about 10(9) cfu/g. The highest inhibitory activity was shown by DM-FP obtained by growing L. plantarum in a defined medium (DM). Significantly, this medium contained an amino acceptor of the aminoacid transamination, namely alpha-ketoglutaric acid, and an aminoacid pool. With loaves prepared using the DM-acid mixture which simulated the DM-FP composition, the same reduction of ropy spoilage as with DM-FP was obtained after 3 days, while the efficacy of the mixture decreased after 7 days. This result suggests the potential involvement of some unknown metabolites in the inhibitory activity of DM-FP. In baked products made with flour based media (M1-FP, M2-FP, M3-FP), no ropy symptoms were noticeable after 3 days storage although a considerable Bacillus count was detected. DM-FP was as effective as calcium propionate (0.3% w/w, based on flour mass) in prolonging the Bacillus free-shelf life of yeast-leavened bread for 7 days.  相似文献   
94.
An approach aimed to the quantitative assessment of the risk caused by escalation scenarios triggered by fire was developed. Simplified models for the estimation of the vessel time to failure (ttf) with respect to the radiation intensity on the vessel shell were obtained using a multi-level approach to the analysis of vessel wall failure under different fire conditions. Each vessel “time to failure” calculated by this approach for the specific fire scenario of concern was compared to a reference time required for effective mitigation actions and related to the escalation probability. The failure probability of each vessel was correlated to the probability of scenarios involving multiple vessel failure as a consequence of the primary fire, thus allowing a comprehensive assessment of domino scenarios triggered by fire. The application of the methodology to the analysis of several case-studies allowed the estimation of the quantitative contribution of escalation events triggered by fire to the overall individual and societal risk indexes.  相似文献   
95.
JT-60SA is a superconducting tokamak to be assembled and operated at the JAEA laboratories in Naka (Japan). The tokamak is designed, manufactured and operated under the funding of the Broader Approach Agreement (between the government of Japan and the European Commission) and of the Japan Fusion National Programme; JT-60SA aims to prepare, support and complement the ITER experimental programme. The European contribution to the JT-60SA is, for a large fraction, procured by France, Germany, Italy, Spain and Belgium.This paper summarizes the activities carried out at F4E to develop a user-friendly software tool able to assess in real-time if an operational scenario could be structurally withstood by the magnet system of JT-60SA. Such tool is based on a theoretical formulation which is supported by a series of dedicated finite element method (FEM) calculations, and is able to provide a comparative assessment of any candidate scenario with respect to the baseline scenarios, and a quantitative assessment of all electro magnetic (EM) forces acting on the magnet system at any time during the candidate scenario. The tool as it is presented is specifically designed to be used for the JT-60SA tokamak, though it is designed so to that its usage could be extended easily to any other tokamak.  相似文献   
96.
97.
Hydrogen energy applications often require that systems are used indoors (e.g., industrial trucks for materials handling in a warehouse facility, fuel cells located in a room, or hydrogen stored and distributed from a gas cabinet). It may also be necessary or desirable to locate some hydrogen system components/equipment inside indoor or outdoor enclosures for security or safety reasons, to isolate them from the end-user and the public, or from weather conditions.Using of hydrogen in confined environments requires detailed assessments of hazards and associated risks, including potential risk prevention and mitigation features. The release of hydrogen can potentially lead to the accumulation of hydrogen and the formation of a flammable hydrogen-air mixture, or can result in jet-fires. Within Hyindoor European Project, carried out for the EU Fuel Cells and Hydrogen Joint Undertaking safety design guidelines and engineering tools have been developed to prevent and mitigate hazardous consequences of hydrogen release in confined environments. Three main areas are considered: Hydrogen release conditions and accumulation, vented deflagrations, jet fires and including under-ventilated flame regimes (e.g., extinguishment or oscillating flames and steady burns). Potential RCS recommendations are also identified.  相似文献   
98.
The potentialities for 1-aryl-5-methyl-3-hydroxypyrazoles as intermediates in the field of dyes have been analysed. Some azoic derivatives have been synthesized and both electronic spectra and tinctorial properties on various substrates (wool, nylon, polyester, plasticized PVC) examined. The effect of substituents on the position of the long wavelength absorption maxima is discussed in terms of Hammett σ constants and interesting relationships are obtained. For each application the most important technical properties are assessed and significant fastness to various agents is evaluated.Finally a comparison with properties of similar pyrazol-5-one derivatives is made.  相似文献   
99.
New compositions of bioactive glasses are proposed in the CaO–MgO–SiO2–Na2O–P2O5–CaF2 system. Mineralization tests with immersion of the investigated glasses in simulated body fluid (SBF) at 37°C showed that the glasses favour the surface formation of hydroxyapatite (HA) from the early stages of the experiments. In the case of daily renewable SBF, monetite (CaHPO4) formation competed with the formation of HA. The influence of structural features of the glasses on their mineralization (bioactivity) performance is discussed. Preliminary in vitro experiments with osteoblasts’ cell-cultures showed that the glasses are biocompatible and there is no evidence of toxicity. Sintering and devitrification studies of glass powder compacts were also performed. Glass-ceramics with attractive properties were obtained after heat treatment of the glasses at relatively low temperatures (up to 850°C).  相似文献   
100.
OBJECTIVE: To determine whether individual surgeon experience is associated with improved short-term clinical and economic outcomes for patients with benign and malignant thyroid disease who underwent thyroid procedures in Maryland between 1991 and 1996. SUMMARY BACKGROUND DATA: There is a prevailing belief that surgeon experience affects patient outcomes in endocrine surgery, but there is a paucity of objective evidence outside of clinical series published by experienced surgeons that supports this view. METHODS: A cross-sectional analysis of all patients who underwent thyroidectomy in Maryland between 1991 and 1996 was conducted using a computerized statewide hospital discharge data base. Surgeons were categorized by volume of thyroidectomies over the 6-year study period: A (1 to 9 cases), B (10 to 29 cases), C (30 to 100 cases), and D (>100 cases). Multivariate regression was used to assess the relation between surgeon caseload and in-hospital complications, length of stay, and total hospital charges, adjusting for case mix and hospital volume. RESULTS: The highest-volume surgeons (group D) performed the greatest proportion of total thyroidectomies among the 5860 discharges, and they were more likely to operate on patients with cancer. After adjusting for case mix and hospital volume, highest-volume surgeons had the shortest length of stay (1.4 days vs. 1.7 days for groups B and C and 1.9 days for group A) and the lowest complication rate (5.1 % vs. 6.1% for groups B and C and 8.6% for group A). Length of stay and complications were more determined by surgeon experience than hospital volume, which had no consistent association with outcomes. CONCLUSIONS: Individual surgeon experience is significantly associated with complication rates and length of stay for thyroidectomy.  相似文献   
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