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931.
Vitiligo is an acquired disease characterized principally by patchy depigmentation of skin and overlying hair. Generalized vitiligo (GV), the predominant form of the disorder, results from autoimmune l...  相似文献   
932.
The International Tribunal for the Law of the Sea (ITLOS) was established by the 1982 United Nations Convention on the Law of the Sea as a body to settle disputes between States Parties to the Convention regarding the interpretation or application of the Convention s provisions, including provisions concerning the exercise of the powers of States over shipping and the discharge by states of their responsibilities and obligations in relation to ships.ITLOS is competent to deal with disputes in which a State is alleged to have wrongly interfered with or otherwise restrained the operation of a vessel when it is in a port of the State or within the territorial sea or exclusive economic zone of the State.In its previous judgments, ITLOS has provided clarifications of some important areas of the law of the sea concerning the operation and regulation of shipping by flag States and other states.ITLOS plays a key role in the regime of the Law of the Sea Convention relating to the prompt release of ships and their crews that are arrested or detained in a foreign port.ITLOS also has the possibility to serve as ajudicial organ for the settlement of disputes under other maritime agreements and contracts, if the parties to the agreements or contracts agree to confer jurisdiction on it.There are many advantages to be gained by States and shipping operators from using ITLOS as the body for the settlement of disputes under agreements. These advantages include savings in time and expenses.  相似文献   
933.
Strong restrictions on emissions from marine power plants(particularly SOx,NOx)will probably be adopted in the near future.In this paper,a combined solid oxide fuel cell(SOFC)and steam turbine fuelled by natural gas is proposed as an attractive option to limit the environmental impact of the marine sector.The analyzed variant of the combined cycle includes a SOFC operated with natural gas fuel and a steam turbine with a single-pressure waste heat boiler.The calculations were performed for two types of tubular and planar SOFCs,each with an output power of 18 MW.This paper includes a detailed energy analysis of the combined system.Mass and energy balances are performed not only for the whole plant but also for each component in order to evaluate the thermal efficiency of the combined cycle.In addition,the effects of using natural gas as a fuel on the fuel cell voltage and performance are investigated.It has been found that a high overall efficiency approaching 60%may be achieved with an optimum configuration using the SOFC system.The hybrid system would also reduce emissions,fuel consumption,and improve the total system efficiency.  相似文献   
934.
The basis for design of stiffened plates under longitudinal compression is outlined and predictions using several codes are compared against numerical results from an inelastic beam-column formulation and test results. In order to explore the inherent differences in column behaviour separately from discrepancies arising due to plate panel behaviour, the code predictions are re-evaluated adopting a common plate panel effective width formulation. On this basis, a critical review of code methods is made and some modifications are proposed.

The effect of the magnitude and direction of applied uniform bending on the axial capacity of stiffened plates is investigated by comparing two alternative design approaches, namely an interaction equation and a method based on the Perry equation, against results from numerical analyses and from rigid plastic theory. The interaction equation is invariably more conservative than the Perry approach but its simplicity tends to be convenient for routine design applications. Finally, results of numerical analyses, together with experimental results from previous studies, on continuous stiffened plates under combined axial compression and lateral pressure are presented and available design guidance is discussed.  相似文献   

935.
The United States Environmental Protection Agency (U.S. EPA) and other environmental authorities regulate concentrations of dissolved oxygen (DO) as a measure of nutrient-related eutrophication in estuarine and coastal waters. However, in situ DO concentrations are extremely variable, and their characterization requires an extensive sampling program to provide data over meaningful scales of time and space. In contrast, benthic faunal communities integrate the impacts of low DO over time, and can be rapidly assessed using benthic imaging. The goal of this study was to quantify the relationships between near-bottom dissolved oxygen and measures derived from benthic imaging with a sediment profile camera. We monitored three stations in Narragansett Bay (Rhode Island, USA) for DO and other water quality parameters 15–20 cm above the sediment surface on 15-minute intervals between July and November 2002, and regularly sampled these stations with a sediment profile camera throughout this time period. These soft-sediment stations encompassed several DO environments. We tested for relationships between near-bottom DO and several camera measures, including Nilsson and Rosenberg's Benthic Habitat Quality (BHQ) index, the apparent Redox Potential Discontinuity (aRPD) depth, and various faunal features that can be identified in sediment profile images. Camera measures were examined against a variety of methods of characterizing DO (including mean DO, and the percent of time under various DO thresholds), over a span of time scales from 1 day to 49 days. The best relationship (highest r2) between near-bottom DO and BHQ was found when DO was evaluated as the percent of time under a hypoxic threshold of 2.6 mg l− 1 over a 28-day time scale (by examining DO records over the 28 days preceding each camera deployment). We found that, over several benthic settings, the BHQ index was successful at identifying environments that had experienced relatively high or low DO over the preceding four weeks. Our sediment profile data showed more variability with DO in the intermediate values of BHQ. We conclude that sediment profile camera measures correlate to DO in areas where low DO is the primary stressor, integrate DO over ecologically relevant time scales, and enable sampling over spatial scales that are meaningful for mapping by virtue of rapid deployment and analysis. We submit that sediment profile camera imagery is a useful assessment and mapping tool for environmental managers interested in benthic condition and in first-order quantitative estimates of near-bottom DO regimes in areas where low DO is the primary benthic stressor.  相似文献   
936.
Modern ports need to be inserted in an efficient network in order to exploit all their potential, positively affecting both the efficiency of the local markets and the external costs of the served industries. Moreover, the role of the ports within the whole supply chain is affected by the location and the organization of intermediate facilities—such as logistics parks or inland ports—that heavily influence both the effectiveness of the logistics corridors and the externalities generated by the transport industry. New and adequate infrastructures can then reduce congestions, pollution, and accidents smoothing the whole logistics chains. The proposed study aims at discussing the effects in terms of rail share of the different planned interventions that are aimed at increasing the rail capacity of the network under investigation. In order to achieve this goal, a network optimization model has been solved by the optimizer solver of a spreadsheet. Outcomes can be used in order to improve current transport policies that might foster a more efficient and less impacting hinterland transport solution.  相似文献   
937.
In this paper, the influence of injection parameters on the transition from Premixed Charge Combustion Ignition (PCCI) combustion to conventional diesel combustion was investigated in an optically accessible High-Speed Direct-Injection (HSDI) diesel engine using multiple injection strategies. The heat release characteristics were analyzed using incylinder pressure for different operating conditions. The whole cycle combustion process was visualized with a high-speed video camera by simultaneously capturing the natural flame luminosity from both the bottom of the optical piston and the side window, showing the three dimensional combustion structure within the combustion chamber. Eight operating conditions were selected to address the influences of injection pressure, injection timing, and fuel quantity of the first injection on the development of second injection combustion. For some cases with early first injection timing and a small fuel quantity, no liquid fuel is found when luminous flame points appear, which shows that premixed combustion occurs for these cases. However, with the increase of first injection fuel quantity and retardation of the first injection timing, the combustion mode transitions from PCCI combustion to diffusion flame combustion, with liquid fuel being injected into the hot flame. The observed combustion phenomena are mainly determined by the ambient temperature and pressure at the start of the second injection event. The start-of-injection ambient conditions are greatly influenced by the first injection timing, fuel quantity, and injection pressure. Small fuel quantity and early injection timing of the first injection event and high injection pressure are preferable for low sooting combustion.  相似文献   
938.
This paper puts forward a method of preliminary driver classification, which applies two-criteria based analysis of the phenomenon of driving style. The resulting rank enabled the author to order the drivers according to their driving style, from the most active to the extremely mild. The most active driver in the sense of the two-criteria analysis is the one who covered a test stretch of the road the fastest while changing the position of the accelerator pedal most intensively. The classification of the drivers, along with the measurement data registered during road tests, will subsequently provide the foundation for later modeling of a dynamic classification of the driving style, in the form of a recurrent learning neural network of the Elman’s type.  相似文献   
939.
We investigated perceived travel possibilities (or subjective choice-sets, consideration-sets) of car and train travellers on the main corridors to the city of Amsterdam, The Netherlands, and associations with traveller and trip characteristics. We conducted secondary analysis on a survey sample consisting of 7950 train and 19,232 car travellers. Forty-five percent of train travellers had a car in their objective choice-set, 27% of them would however never use it for this trip. Trip destination city centre, trip purpose, paying for the trip, public transport commitment, traffic congestion and parking problems were associated with consideration of car as alternative. Forty-two percent of car travellers had public transport in their subjective choice-set. The ratio between perceived public transport and objective car travel time stood out as determinant of consideration-sets, next to destination city centre, trip purpose, travel time and private versus company car ownership. On average, car travellers’ perceptions of public transport travel time exceeded objective values by 46%. We estimated that if perceptions would be more accurate, two out of three car travellers that currently do not see public transport as an alternative would include it in their choice-set, and use it from time to time. This effect has strong theoretical and policy implications.  相似文献   
940.
Three families of road noise prediction models can be distinguished. Static noise models only consider free-flow constant-speed traffic with uniformly distributed vehicles. Analytic noise models assume that all vehicles are isolated from one another but account for their mean kinematic profile over the network. Micro-simulation noise models relax the hypothesis of no interaction between vehicles and fully capture traffic flow dynamic effects such as queue evolution. This study compares the noise levels obtained by these three methodologies at signalized intersections and roundabouts. It reveals that micro-simulation noise models outperform the other approaches. Particularly, they are able to capture the effects of stochastic transient queues in under-saturated conditions as well as stop-and-go behaviors in oversaturated regime. Accounting for traffic dynamics is also shown to improve predictions of noise variations due to different junction layouts. In this paper, a roundabout is found to induce a 2.5 dB(A) noise reduction compared to a signalized intersection in under-saturated conditions while the acoustic contributions of both kinds of junctions balance in oversaturated regime.  相似文献   
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