Wind power potential assessment for three buoys data collection stations in the Ionian Sea using Weibull distribution function

The present article utilizes wind measurements from three buoys data collection stations in Ionian Sea to study the wind speed and power characteristics using the Weibull shape and scale parameters. Specifically, the site dependent, annual, and monthly mean patterns of mean wind speed, Weibull parameters, frequency distribution, most probable wind speed, maximum energy carrying wind speed, wind power density and wind energy density characteristics have been analyzed. The Weibull distribution was found to represent the wind speed distribution with more than 90% accuracy, in most of the cases. Moreover, the correlation between the percentages of times the wind speed was above cut-in-speed and the measured mean wind speed for the three selected sites, as the correlation between the aforementioned percentages and the scale parameter c were examined and were found linear. At all these sites, no definite increasing or decreasing trends in annual mean wind speed values could be detective over the data reporting period. The mean values of wind speed, scale parameter, most probable wind speed, maximum energy carrying wind speed, wind power and wind energy density values showed higher values during winter time and lower in summer time in Pylos and Zakynthos. Moreover, Pylos and Zakynthos were found to be the best sites from wind power harnessing point of view.     

Unignited High-Pressure Methane Jet Impinging a Pipe Rack: Practical Tools for Risk Assessment

Although the diffusion of its storage and transport under liquefied conditions, nowadays it is common to have methane in gaseous form in several industrial applications. This leads to safety implications to be considered: hazards are linked to both the high-pressure at which the gas is kept and to its flammability. Scenarios where flammable jets impact an obstacle are of paramount importance because of their possible occurrence. Following a numerical approach, literature shows up that their assessment can be reliably performed by means of only Computational Fluid Dynamics tools. However, despite the improvements of computing power, Computational Fluid Dynamics costs still limit its use in daily risk analysts’ activities. Therefore, considering an accidental jet-obstacle scenario of industrial interest, the present work investigates how a pipe rack can influence the development of a high-pressure methane jet. Based on a Computational Fluid Dynamics analysis, main achievements of this work are a simple criterion able to identify the situations where the pipe rack does not influence the high-pressure methane jet behavior, therefore allowing to identify the scenarios where simpler models can be used (i.e., analytical correlations known for the free jet situation), and, if present, a simple analytical relationship that roughly predicts the influence of the pipe rack without the need of performing complex Computational Fluid Dynamics simulations.     

Fifty Shades of Green? Political differences between elites,members and supporters of Europe Ecologie Les Verts

In recent years, many political parties have created new forms of affiliation and have justified the blurring of membership boundaries with claims that sympathisers would be more representative of the electorate and less radical. Such claims are based on ‘popular wisdom’ inspired by John May’s ‘special law of curvilinearity’, which states that activists hold more extreme views than voters and elites. When this expectation has been tested, results have been at best inconclusive; but testing has so far never used a single survey to compare different groups. Using an online survey of Europe Ecologie Les Verts party members and their extended networks (affiliated supporters, lapsed members, sympathisers), relationships between ideological differences and degree of investment in party activities and decision-making are analysed. The results, contradicting May’s special law along all ideological dimensions other than intra-party democracy, can be explained if May’s narrowly instrumental assumptions about preference formation are rejected.     

结构物损伤预测模型及其在隧道施工中的应用

基于结构物风险评估理论,构建结构物损伤预测模型,并将其应用于隧道施工的研究中,以解决在地下工程施工中引起地上建筑损伤预测的技术难题。将数值模拟与模糊数学隶属度相结合,形成对结构物在隧道工程施工状态下的损伤预测模式,并以西安地铁某区间盾构下穿高铁涵洞为算例,提取相应的智能监测数据对该预测模式的可行性进行验证。结果表明,数值模拟与模糊数学隶属度相结合的结构物损伤预测模型计算效率高,便于操作,适用于隧道工程施工时对地上建筑物的安全评估,能有效解决在地下工程施工中引起地上建筑损伤预测的技术难题。     

多目标模糊决策模型对水环境质量的评价

水质环境质量评价宜采用多项控制指标进行综合评价。在模糊理论和考虑优先隶属度的基础上,通过实例推导出水环境质量多目标模糊决策评价图,用以说明两组或两组以上的数据或变量的相互联系,以非常直观地分析概念,讨论水质变化趋势。模型可客观地评价水域单元的各类水质指标。     

Integration of distance, direction and habitat into a predictive migratory movement model for blue-winged teal (Anas discors)

Historically, the migration of birds has been poorly understood in comparison to other life stages during the annual cycle. The goal of our research is to present a novel approach to predict the migratory movement of birds. Using a blue-winged teal case study, our process incorporates not only constraints on habitat (temperature, precipitation, elevation, and depth to water table), but also approximates the likely bearing and distance traveled from a starting location. The method allows for movement predictions to be made from unsampled areas across large spatial scales. We used USGS’ Bird Banding Laboratory database as the source of banding and recovery locations. We used recovery locations from banding sites with multiple within-30-day recoveries were used to build core maximum entropy models. Because the core models encompass information regarding likely habitat, distance, and bearing, we used core models to project (or forecast) probability of movement from starting locations that lacked sufficient data for independent predictions. The final model for an unsampled area was based on an inverse-distance weighted averaged prediction from the three nearest core models. To illustrate this approach, three unsampled locations were selected to probabilistically predict where migratory blue-wing teals would stopover. These locations, despite having little or none data, are assumed to have populations. For the blue-winged teal case study, 104 suitable locations were identified to generate core models. These locations ranged from 20 to 228 within-30-day recoveries, and all core models had AUC scores greater than 0.80. We can infer based on model performance assessment, that our novel approach to predicting migratory movement is well-grounded and provides a reasonable approximation of migratory movement.     

POLLUTANT LOADING CAPACITY FOR THE BLACK RWER,CHEHALIS RWER SYSTEM,WASHINGTON1

ABSTRACT: The Black River, a tributary of the Chehalis River in western Washington State, has a history of widespread low dissolved oxygen (DO), anoxia in some locations, and fish kills. As part of a Total Maximum Daily Load (TMDL) study, environmental data were collected during two summer dry seasons and simulations were conducted with the WASP5 model to assess the effect of biochemical oxygen demand ( BOD ), ammonia, and nutrient loads on DO in the Black River. DO levels were below the State water quality regulatory criterion of 8.0 mg/L in almost all locations during the study. The slow middle reach of the river showed stratified conditions, with anoxia in some of the deepest pools. Based on model simulations, DO was found to still fall below the 8.0 mg/L criterion in the entire mainstem under “natural” conditions, and eutrophication was identified as a potential problem in the middle reach. A TMDL was proposed for BOD and ammonia that would prevent significant degradation of DO in the Black River. To prevent eutrophic conditions in the Black River, a TMDL for total phosphorus was proposed that establishes a protective criterion of 0.05 mg/L for the middle river during the dry low-flow season.     

When is overfishing underfishing?

The term overfishing is being used with increasing frequency to designate an undesirable level of fisheries exploitation. All too often, however, the term is taken as being self-evident. This article demonstrates that many definitions of overfishing are possible, depending essentially on what objective is being pursued for the fishery. Various possible biological and economic objectives are considered, both in a static and dynamic model of the fishery. Consideration is given to the best utilization of the fish stock from the viewpoint of the individual fishermen as well as that of society. It is shown that overfishing by one definition may be underfishing by another, and it is concluded therefore that anyone using the term overfishing ought, as a matter of course, to define it.     

汕头市降雨量的概率分布模型

根据汕头市实测的年最大日降雨量资料,采用极值Ⅰ型、极值Ⅱ型、极值Ⅲ型和Ｗｅｉｂｕｌｌ分布等四种极值分布模型模拟,从而确定了年的最大日降雨量的概率模型．并根据年的各时段的最大降雨量仪器记录产生概率模型,建立各时段降雨量之间的相互关系,得到汕头市降雨量的概率分布模型,作为汕头市内涝分析的依据。     

地质灾害危险性区划评价中隶属度函数构造方法的探讨

运用模糊综合评判方法进行地质灾害危险性区划评价的过程中,隶属函数的构造是一项复杂而重要的工作。在总结前人经验的基础上,对参与区划评价的定量因子的隶属度计算采用了一个简化的"二值模型"的方法构造隶属函数,计算隶属度,收到较好的效果。