ANALYSIS OF PUMPING TESTS: SIGNIFICANCE OF WELL DIAMETER,PARTIAL PENETRATION,AND NOISE1

ABSTRACT: The nonlinear least squares (NLS) method was applied to pumping and recovery aquifer test data in confined and unconfined aquifers with finite diameter and partially penetrating pumping wells, and with partially penetrating piezometers or observation wells. It was demonstrated that noiseless and moderately noisy drawdown data from observation points located less than two saturated thicknesses of the aquifer from the pumping well produced an exact or acceptable set of parameters when the diameter of the pumping well was included in the analysis. The accuracy of the estimated parameters, particularly that of specific storage, decreased with increases in the noise level in the observed drawdown data. With consideration of the well radii, the noiseless drawdown data from the pumping well in an unconfined aquifer produced good estimates of horizontal and vertical hydraulic conductivities and specific yield, but the estimated specific storage was unacceptable. When noisy data from the pumping well were used, an acceptable set of parameters was not obtained. Further experiments with noisy drawdown data in an unconfined aquifer revealed that when the well diameter was included in the analysis, hydraulic conductivity, specific yield and vertical hydraulic conductivity may be estimated rather effectively from piezometers located over a range of distances from the pumping well. Estimation of specific storage became less reliable for piezometers located at distances greater than the initial saturated thickness of the aquifer. Application of the NLS to field pumping and recovery data from a confined aquifer showed that the estimated parameters from the two tests were in good agreement only when the well diameter was included in the analysis. Without consideration of well radii, the estimated values of hydraulic conductivity from the pumping and recovery tests were off by a factor of four.     

德阳市区域环境噪声普查优化布点方法研究

本文通过对德阳市区域环境噪声普查优化布点方法的研究,提出了一种简便、快速、实用的区域环境噪声普查优化布点方法。     

长管拖车气瓶声发射技术定位检测方法分析

长管拖车气瓶是盛装有危险介质的高压储运设备,能否进行及时有效的检验,是保障其安全可靠运行的关键。我国开始长管拖车气瓶的应用、研究时间不长,相关积累不充分,而现有的水压试验法对危险性缺陷不敏感。声发射检测是动态缺陷整体检测的有效方法,将其应用于长管拖车气瓶的检测可节省大量的时间和人力、物力。对框架式长管拖车气瓶进行了不拆车声发射定位试验,测定了瓶体上断铅源声发射信号随距离衰减的曲线,采用数值分析方法得到曲线拟合方程式,探讨总结出定位过程中声发射采集的关键参数——门槛、探头间距和声速的设定方法和初始值,以及拖车结构对定位的影响,为长管拖车气瓶声发射定期检验工作的开展提供了参考,在分析定位源强度、定位方法研究方面有重要意义。     

Financing of internal displacement: excerpts from the Sri Lankan experience

This paper investigates how internally displaced persons (IDPs) in Batticaloa, Sri Lanka, financed their first year of displacement. We conducted extensive fieldwork in August 2007 in numerous welfare centres in Batticaloa that have received persons displaced from the Mutur divisional secretariat (DS) in the Trincomalee district. The sample was selected from the village of Sampur in Mutur DS. The displaced from Sampur are of Tamil origin and our findings reveal certain coping strategies that may be particular to this community, including the selling or mortgaging of gold jewellery to address the effects of displacement. We found that the IDPs in this region rely heavily on jewellery and other forms of savings to ensure their survival. There is also strong evidence to support the critically important coping role played by livelihoods. These coping strategies have enabled the IDP households in the present sample to live marginally above the poverty line.     

兼顾公平与效率的无人机应急中继通信选址优化问题

为提高应急救援中无人机应急中继通信资源配置的公平与效率,在考虑无人机中继通信覆盖范围限制、各受灾用户集群点分布情况、受灾群众公平性感知的基础上,构建以最大化系统吞吐量为效率目标、最小化受灾群众公平损失值为公平目标的无人机应急中继通信选址多目标0-1非线性整数规划模型,采用基于k-means的模拟退火算法对其进行求解,并以实际案例为背景构造算例,验证本文提出模型和算法的可行性与有效性,并进行多目标分析及参数敏感性分析。研究结果表明：本文提出的模型和算法能在较短时间得到无人机应急中继通信选址方案,保证所有受灾用户集群点获得通信中继;同时,确定最佳无人机设备数量,验证公平目标与效率目标存在悖反关系。     

气幕隔尘法在电炉屋顶烟罩排烟系统中的应用分析

通常电炉加料和出钢时的烟气均通过屋顶烟罩捕集,但使用效果不够理想。为提高屋顶烟罩的捕集效率,节省大规模排烟量和风机能耗,提出更加经济的气幕隔尘法用于辅助电炉屋顶烟罩排烟。即在屋顶烟罩底部形成一个无形透明的屏障,以阻止电炉加料或出钢时的向上烟气不因车间横向气流的干扰而向屋顶烟罩外扩散。结合工程项目分析了气幕隔尘新技术的应用前景。     

Selling displaced people? A multi‐method study of the public communication strategies of international refugee organisations

The world has seen a major increase in forced displacement since 2011. As a growing number of states implement restrictive refugee policies, public communication has become essential for refugee organisations. This study analysed, therefore, three international refugee organisations’ discursive strategies towards the recent Syrian crisis, as well as their production and the social context. A critical discourse analysis of international press releases (N=122) and six semi‐structured interviews with press and regional officers revealed that the observed actors largely dehumanise displaced people and subordinate them to the ‘Western self’ and state interests; displaced people hardly ever acquire their own voice. The study found that the medium characteristics of press releases and the importance of media attention result in a depersonalising humanitarian discourse. In addition, there were indications of a post‐humanitarian discourse that reproduced the humanitarian sector's ‘marketisation’. Finally, the examined organisations use the political realist cross‐issue persuasion strategy, displaying displaced people as resettlement objects.     

Investigation on the degradation and opening behavior of knife blade burst disks

Burst disks are often used as the highest level of defense against over pressure. 36 knife blade burst disks were spent to test their steadfastness and reliability. Half of the burst disks were subjected to stress similar to normal use in a plant. They showed no sign of degradation compared to the unstressed disks. However many disks failed to burst at the specified pressure and none opened with the specified cross section. These parameters are essential for dimensioning pressure relief equipment.     

Strategic alignment with organizational priorities and work engagement: A multi‐wave analysis

This study advances the limited research on work alignment and work engagement by investigating how perceived alignment of job tasks and organizational strategic priorities (strategic alignment) influences work engagement. Measures of job control and work social support were also included to enable comparisons between strategic alignment and other well‐established job resources. A total of 1011 employees of an Australian state police service responded to three electronic, self‐report surveys. A reciprocal model was assessed over three waves of data, with varying time lags: 18 (Time 1 to Time 2), 12 (Time 2 to Time 3), and 30 months (Time 1 to Time 3). Longitudinal, reciprocal relationships were observed for work engagement and job control, strategic alignment, and colleague support. Work engagement also predicted supervisor support over time (reverse effect). This study demonstrated that, in addition to job resources, perceived alignment of job tasks and organizational priorities plays an important role in maintaining high levels of work engagement over time. Copyright © 2013 John Wiley & Sons, Ltd.