Environmental Impact Assessment of Onshore Wind Farms in the Region of Central Greece Using a Modified RIAM Method

Wind energy is one of the most basic forms of renewable energy,which shows an increasing rate of development worldwide and also at the European level.However,this rapid deployment of wind farms makes the need for an impact assessment of this type of projects on the natural and man-made environment imperative.The present paper aims to identify and assess the environmental impacts of wind farm projects in the Region of Central Greece.A modified Rapid Impact Assessment Matrix(RIAM)method is used for this purpose.The methodology includes the identification of the existing onshore wind farm projects in the study area,the appropriate modifications of the RIAM method to respond to the characteristics of the projects and the study area,the qualitative assessment of their potential impacts during construction and operational phases and the computation of the Environmental Performance Grade(EPG)of projects based on the pro-posed modified RIAM method.The results reveal that although there are some slight negative impacts on the natural environment of the study area,the examined wind farms contribute positively both to the atmosphere and to the socio-economic environment of the study.This study extends the potential for using RIAM as a tool in environmental impact assessment studies of renewable energy projects.

Prioritization of Water Resources Management Problems in North Central Nigeria Using Rapid Impact Assessment Matrix (RIAM)

This study employed the Rapid Impact Assessment Matrix (RIAM) to prioritize the water resources management problems in the North Central Nigeria. This was done through the assessment of the status of water resources management in the region, evaluation of existing policy and strategy of water management, identification of the management problems and the prioritization with RIAM. The stakeholders identified water resources management problems, ranked them in other of severity in different categories and also evaluated them using the RIAM techniques in the administered questionnaire. Eleven problems were analyzed based on the physical/chemical, biological/ecological, social/cultural and economic/operational factors using several impact indicators. Scores were assigned, the RIAM models applied and the averages taken to arrive at the final assessment scores. The two major water resources management problems identified are: 1) inadequate funds for further agricultural, hydroelectric, navigation and industrial development;2) poor data collection and banking. These problems were prioritized by RIAM in order of severity for urgent intervention. The RIAM technique has made a key contribution to the prioritization of water resources management by providing insights into urgent problems according to stakeholders and thus guides the policy maker in appropriate decision making.

Detecting Impact Damage in Carbon Fabric/epoxy-matrix Composites by Ultrasonic F-scan and Electrical Resistance Measurement

The status and the variation of electrical resistance of impacted carbon fiber/epoxy-matrix composites were studied by ultrasonic F-scan and electrical resistance measurement The experimental results shows that impact damage energy threshold value of carbon fabric/epoxy-matrix composites can determine by using ultrasonic F-scan. When the impact energy exceeds the threshold value, damage is generated in composites. Electrical resistance of impacted composites is changed owing to the contact of each carbon fiber unit in composites, which cause a change of the series-parallel in conductors. The veracity of detecting impact damage in composites can be improved in this case.

Electron impact excitation of Ni-like gold studied by Dirac R-matrix method

We calculate the electron impact excitation of Ni-like gold by using the Dirac R-matrix theory, and the cor- responding collision strengths and effective collision strengths are obtained. In the calculations of the level energy, （1sZ2sZ2p6）3sZ3p63d10, 3s23p63d94/, 3s23p53d104/, and 3s3p63d104/（l = 0, 1,2,3） configurations are included and 107 fine-structure levels are generated. In the calculations of the collision strengths, only the first 59 levels are included. Com- parisons are made with the distorted wave （DW） results of Zeng et al. for both collision strengths and effective collision strengths. For the collision strengths, the two sets of calculations are in excellent agreement for most of the transitions. However, because of the inclusion of the resonances, our effective collision strengths are generally several times larger than those of Zeng et al.. The accuracy of our calculations is assessed.

Evaluation of Impact Damage Tolerance in Carbon Fabric/epoxy-matrix Composites by Electrical Resistance Measurement

Impact damage tolerance is provided in intensity design on composites. The compression intensity of impacted composites requires more than 60% of its original intensity. The influence of impact on compressive intensity and electrical resistance of carbon fabric/epoxy-matrix composites was studied in this paper. The experimental results shows that impact can cause damage in composites, degenerate compressive intensity, and increase resistance. The electrical resistance change rate was used as an evaluation indicator of impact damage tolerance of composites. Impact damage, which results from the applying process of composites, can be identified in time by electrical resistance measurement. So, the safety performance of composites can also be improved.

Pulse-Impact on Microstructure of Liquid-Phase-Pulse-Impact Diffusion Welded Joints of Particle Reinforcement Aluminum Matrix Composites at Various Temperatures

Investigation was to study the influence of pulse-impact on microstructure of Liquid-Phase-Pulse-Impact Diffusion Welding (LPPIDW) welded joints of aluminum matrix composite SiCp/A356, SiCp/6061Al, Al2O3p/6061Al. Results showed that under the effect of pulse-impact: 1) the interface state between reinforcement particle (SiC, Al2O3) and matrix was prominently;2) the initial pernicious contact-state of reinforcement particles was changed from reinforcement (SiC, Al2O3)/reinforcement (SiC, Al2O3) to reinforcement (SiC, Al2O3)/matrix/ reinforcement (SiC, Al2O3);3) the density of dislocation in the matrix neighboring to and away from the interface in the matrix was higher than its parent composite;and 4) the intensively mutual entwisting of dislocation was occurred. Studies illustrated that: 1) deformation was mainly occurred in the matrix grain;and 2) under the effect of pulse-impact, the matrices around reinforcement (SiC, Al2O3) particles engendered intensive aberration offered a high density nucleus area for matrix crystal, which was in favor of forming nano-grains and improved the properties of the successfully welded composite joints.

修正-联合正则化的冲击载荷识别与响应重构

针对传统结构响应重构中正则化方法对冲击载荷峰值识别精度低、非加载区识别结果振荡且识别精度易受噪声干扰等问题,提出基于修正-联合正则化的冲击载荷识别与结构响应重构方法.基于状态空间模型,推导冲击载荷及结构响应的重构方程.对测量响应降噪,利用降噪后响应与识别响应的差值修正L2正则化解.联合L1正则化解的稀疏性优势,在保证冲击载荷非加载区域识别稳定的同时,获得更高精度的峰值识别结果,实现结构动态响应的重构.通过数值和实验案例验证了所提方法的有效性,对比了传递矩阵法和粒子滤波法的响应重构效果.结果表明,所提方法具有良好的抗噪性,能够较准确地识别冲击载荷,有效地重构结构动态响应.

SiC/SiC复合材料层板低速冲击及其剩余强度试验研究

高速飞行器中的陶瓷基复合材料结构在服役过程中不可避免地会遇到低速冲击问题,低速冲击后的损伤形式以及剩余承载能力是影响飞行器结构安全的关键问题。本研究以二维编织SiC/SiC复合材料板件为研究对象,在不同能量下开展了低速冲击试验,分析了低速冲击载荷下试验件的表面损伤状态,通过计算机断层扫描技术观察了试验件内部的损伤形貌,结合冲击过程中的冲击响应曲线以及应变历史曲线,分析了SiC/SiC复合材料低速冲击过程的损伤机理。针对含勉强目视可见损伤的试验件开展了冲击后剩余强度试验,研究了勉强目视可见损伤对SiC/SiC复合材料剩余承载性能的影响。结果表明,在低速冲击载荷的作用下,试验件的表面损伤主要包括无表面损伤、勉强目视可见损伤、半穿透损伤以及穿透损伤,试验件的内部损伤主要有锥形体裂纹、纱线断裂以及分层损伤。低速冲击损伤会严重影响SiC/SiC复合材料的剩余性能,虽然试验件损伤勉强目视可见,但其剩余压缩强度为无损件81%,剩余拉伸强度仅为无损件的68%。

基于D-I-M协同模型的企业数字化转型财务管理风险识别研究

数字化正在重塑经济发展的轨道,成为赋能经济增长新动力。精准识别财务管理风险中的关键指标及其相互关系,对企业更好地完成数字化转型尤为关键。融合企业人力、运营、财务、环境4个基本维度,从链式传导视角构建转型背景下企业财务管理风险指标体系。通过决策试验与评价实验室(DEMATL)法,分析各影响因素之间中心度和原因度关系,并利用解释结构模型(ISM),将矩阵进一步分析得到影响因素的层级划分,归纳影响因素之间的内在指向关系,最后运用交叉影响矩阵相乘(MICMAC)法计算各因素的驱动—依赖关系以判断其属性类别。提出通过D-I-M协同分析的方法,识别财务管理风险路径,为企业进行多链融合数字化转型、规避财务管理风险提供参考。

2D-SiC/SiC复合材料的弹丸冲击损伤及冲击后拉伸性能

连续纤维增韧陶瓷基复合材料以其良好的高温性能而被广泛应用在航空发动机等高温部件处,但服役过程中容易受到异物碎片冲击,这受到了广泛关注。研究采用轻气炮对化学气相渗透(CVI)技术制备的2D-SiC/SiC试样进行弹丸冲击,利用高速摄像机记录冲击过程,使用光学显微镜和CT观察异物损伤(FOD)的表面和内部结构,探讨了2D-SiC/SiC复合材料的高速冲击损伤特性。结果表明,2D-SiC/SiC复合材料的高速冲击损伤形式包括锥形裂纹、层间分层、纤维断裂以及基体压溃等。通过表征损伤发现,试件背部损伤和边缘处分层损伤由反射拉伸波造成,随着冲击速度提升,弹丸与拉伸波共同作用会造成试件穿透,试件边缘分层损伤减弱。对高速冲击后的试件进行准静态拉伸试验,明确了剩余力学性能与冲击速度、弹丸直径的关系,表明剩余拉伸强度是表征冲击损伤程度的有效参数。同时,采用数字图像相关(DIC)方法获得拉伸过程中的应变分布,并结合不同弹丸直径、冲击速度冲击后的剩余拉伸强度,进一步对比探究不同变量对冲击损伤的影响。研究结果表明弹丸直径是高速冲击损伤程度的主要影响因素。

基于风险矩阵法的合肥新桥国际机场鸟击风险评价

为了给机场管理部门制定长期的、靶向性的、动态的鸟击防范对策提供理论依据,通过对合肥新桥国际机场开展一整年的鸟类调查(2021年1月—12月,共记录鸟类22698只),发现鸟类17目49科171种,选取鸟类的体重、集群、数量、飞行高度和活动时间5种鸟击影响因子为评价指标,使用风险矩阵法评价不同鸟种的鸟击风险,划分了高、中、低3个鸟击风险等级及相应风险接受准则。评价结果表明:在机场活动的这些鸟类中,可导致高风险鸟击的有10种、中风险的有15种,其余的146种为低风险。将评价结果与机场2014—2021年间发生的、已知肇事鸟种的179起鸟击事件进行对比,显示评价为高风险的10种鸟,年均鸟击次数为1起·种^(-1),导致过3起鸟击征候;中风险的15种鸟则为0.4起·种^(-1),导致过1起鸟击征候;低风险的146种鸟低至0.04起·种^(-1),未导致过鸟击征候。说明本研究采用的风险矩阵法及选取的评价指标适用于合肥新桥国际机场的鸟击风险评价。评价结果为合肥新桥国际机场的鸟击防范工作提供了必需的基础数据。

基于风险概率与影响矩阵的水利工程施工危险源评价

对水利工程施工危险源进行识别评价,能够有效地降低安全事故的发生率。本文主要基于风险概率与影响矩阵进行水利工程施工危险源评价,总结了施工风险源识别与计量方法,并结合实际案例,从发生概率和影响程度两个方面识别计量了施工风险源,并采用风险概率与影响矩阵对施工风险源进行分级管理。研究结构表明:一般危险源3项,重大危险源19项,严重危险源8项。本文研究旨在提出一种水利工程施工风险源评价方法,为施工风险源管理提供决策依据。

基于网络映射的网络服务社群发现及全局表示

针对当前网络拓扑以设备类型为标注,难以反映设备节点间服务关系的问题,提出了一种基于服务映射的网络服务节点划分算法,通过网络节点间服务映射关系,判断服务社群归属,找寻网络服务的关键节点及节点间从属关系并在传统隶属矩阵的基础上引入虚拟社群,使网络服务社群隶属关系影响度算法不仅能反映节点的社群隶属度,还能够反映节点的全局影响度。在LFR网络实验中,将该算法与同类算法进行算法敏感度和性能对比,在Internet2 OS3E仿真实验中通过模拟拒绝服务攻击验证算法划分的有效性。对比实验结果表明服务映射算法具有阈值选择低敏感性和高实用性的特点,且性能优于同类算法。仿真实验表明服务社群划分有效且能够反映节点服务间的关联性。

New Model for Environmental Impact Assessment of Tunneling Projects

Designers of infrastructure are aware that the government, owners and users become more and more concerned about negative environmental impacts of tunnels, so environmental assessment of tunnels are becoming an issue in the process of tunnel design. In this study, to assess tunnels in construction and operation phases, the matrix method, through which the “Impacting Factors” and “Environmental Components” are determined, is also outlined. The affected environment was divided into thirteen components, such as Ecology, Surface water, Air quality, etc. In this paper, matrix method was applied to evaluate the impact of tunneling in three typical tunnels and compare them with standard diagrams of Environmental Components that were derived and introduced. These tunnels were: Urban Utility tunnel in Tehran, Eurasia tunnel in Istanbul and Tsuen Wan drainage tunnel in Hong Kong. Based on the acquired results, the present paper finally concluded that among three cases, Tsuen Wan drainage tunnel affects the environment in construction phase more than others, while Eurasia tunnel effects on air quality are more significant in operation phase.

Uncovering causes and effects of desertification using a Leopold matrix in Binh Thuan Province,Vietnam

Vietnam is a coastal country projected to be heavily affected by climate change.Binh Thuan Province is part of the driest region of Vietnam and is prone to desertification.An expert panel participated in developing a Leopold matrix which allowed for identification of desertification impact factors on the province's socioeconomic activities and assessment of the strength of cause-effect relationships in terms of magnitude and importance.Land use planning,surface water,and the length of the dry season are considered the most important causes,with the overall highest scores for both magnitude and importance in the cause-effect relationship.The largest effects of the different factors are perceived on water supply for agriculture and household use.Water availability and land use planning are important remedial action domains,while drought and land cover require monitoring to assess impacts.The indicators of cause and effect can be used in a longer-term general monitoring and assessment framework to combat desertification in the area.

The Power-weakness Ratios (PWR) as a Journal Indicator： Testing the ＂Tournaments＂ Metaphor in Citation Impact Studies

Purpose： Ramanujacharyulu developed the Power-weakness Ratio （PWR） for scoring tournaments. The PWR algorithm has been advocated （and used） for measuring the impact of journals. We show how such a newly proposed indicator can empirically be tested. Design/methodology/approach： PWR values can be found by recursively multiplying the citation matrix by itself until convergence is reached in both the cited and citing dimensions; the quotient of these two values is defined as PWR. We study the effectiveness of PWR using journal ecosystems drawn from the Library and Information Science （LIS） set of the Web of Science （83 journals） as an example. Pajek is used to compute PWRs for the full set, and Excel for the computation in the case of the two smaller sub-graphs： （1） JASIST＋ the seven journals that cite JASISTmore than 100 times in 2012; and （2） MIS Quart＋ the nine journals citing this journal to the same extent. Findings： A test using the set of 83 journals converged, but did not provide interpretable results. Further decomposition of this set into homogeneous sub-graphs shows that--like most other journal indicators--PWR can perhaps be used within homogeneous sets, but not across citation communities. We conclude that PWR does not work as a journal impact indicator; journal impact, for example, is not a tournament. Research limitations： Journals that are not represented on the ＂citing＂ dimension of the matrix--for example, because they no longer appear, but are still registered as ＂cited＂ （e.g. ARIST）-distort the PWR ranking because of zeros or very low values in the denominator. Practical implications： The association of＂cited＂ with ＂power＂ and ＂citing＂ with ＂weakness＂ can be considered as a metaphor. In our opinion, referencing is an actor category and can bestudied in terms of behavior, whereas ＂citedness＂ is a property of a document with an expected dynamics very different from that of＂citing.＂ From this perspective, the PWR model is not valid as a journal indicator. Originality/value： Arguments for using PWR are： （1） its symmetrical handling of the rows and columns in the asymmetrical citation matrix, （2） its recursive algorithm, and （3） its mathematical elegance. In this study, PWR is discussed and critically assessed.

Interlaminar Fracture Toughness and Low-Velocity Impact Resistance of Woven Glass Epoxy Composite Laminates of EP3 Grade

This work presents the delamination resistance of woven glass fibre reinforced polymers (GFRP) and its influence on GFRP’s resistance to point impact. Two different types of laminates were fabricated by hand lay-up technique;(i) woven glass fibre epoxy matrix laminates and (ii) woven glass fibre epoxy matrix laminates with 3% graphite particulate fillers. End Notch Flexure (ENF) test was adopted for the measurement of delamination resistance. The two GFRPs laminates show similar mode II delamination resistance. At impact velocities between 2.215 and 4.429 m/sec, the GFRP developed a smaller damage size than the graphite-based GFRP laminates, indicating higher impact toughness. Difference of the impact resistance between the two GFRPs is mainly on the impact damage size developed. The total energy absorbed during the impact remains the same, which is independent of mode II delamination resistance of the GFRP. The history of relevant dynamic and energetic quantities, both to synthesize the dependency of the energy parameters and force threshold values on the impact velocity are discussed.

基于ISM-MICMAC的煤矿工人违章行为影响因素研究

为探究煤矿工人违章行为影响因素及其相互作用关系,建立了违章行为影响因素指标体系,并采用解释结构模型(ISM)和交叉影响矩阵相乘法(MICMAC),深入剖析了影响因素之间的逻辑关系,构建了影响因素的多级递接结构模型及驱动力-依赖度象限分类图。结果表明:煤矿工人违章行为影响因素可划分为4级3阶的多级递接结构;安全知识技能、安全意识水平、安全行为习惯、自保互保意识属于依赖簇,具有强依赖性,是影响违章行为的重要因素;安全生产投入、安全管理制度、矿领导安全理念、管理者安全意识、企业安全氛围属于独立簇,具有强驱动力,是影响违章行为的关键因素。

基于ISM-MICMAC的建筑安全疏散中的人为因素影响研究

人为因素是影响安全疏散的主要因素,系统分析人为因素及其作用机理对提升建筑疏散效果具有重要作用。研究通过系统文献综述和内容分析法确定28个人类特性因素、14个运动特性因素,以及6个管理人员因素和6个管理因素,共54个建筑疏散安全人因。利用Python算法编程,构建解释结构模型及递阶结构图,结合交叉影响矩阵相乘法将影响因素划分为Li(i=1~10)10个层级。解析建筑安全疏散人因影响机制可为疏散仿真模型进一步发展、虚拟人群仿真技术真实反映人群特性、建筑安全疏散设计与管理提供有效建议。

Integrated guidance and control design for missile with terminal impact angle constraint based on sliding mode control

Aimed at the guidance requirements of some missiles which attack targets with terminal impact angle at the terminal point,a new integrated guidance and control design scheme based on variable structure control approach for missile with terminal impact angle constraint is proposed.First,a mathematical model of an integrated guidance and control model in pitch plane is established,and then nonlinear transformation is employed to transform the mathematical model into a standard form suitable for sliding mode control method design.A sufficient condition for the existence of linear sliding surface is given in terms of linear matrix inequalities（LMIs）,based on which the corresponding reaching motion controller is also developed.To verify the effectiveness of the proposed integrated design scheme,the numerical simulation of missile is made.The simulation results demonstrate that the proposed guidance and control law can guide missile to hit the target with desired impact angle and desired flight attitude angle simultaneously.