Guides to pollution prevention : the mechanical equipment repair industry.

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Collision repair technician cluster /

Project staff: Ron Engstrom, Shannon Pekins.--P. [2] of cover.

Industry wage survey.

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Structural performance of reinforced concrete beams repairing from spalling

The effectiveness of a repair work for the restoration of spalled reinforced concrete (r.c.) structures depends to a great extent, on their ability to restore the structural integrity of the r.c. element, to restore its serviceability and to protect the reinforcements from further deterioration. This paper presents results of a study concocted to investigate the structural performance of eight spalled r.c. beams repaired using two advanced repair materials in various zones for comparison purposes, namely a free flowing self compacting mortar (FFSCM) and a polymer Modified cementitious mortar (PMCM). The repair technique adopted was that for the repair of spalled concrete in which the bond between the concrete and steel was completely lost due to reinforcement corrosion or the effect of fire or impact. The beams used for the experiment were first cast, then hacked at various zones before they were repaired except for the control beam. The beam specimens were then loaded to failure under four point loadings. The structural response of each beam was evaluated in terms of first crack load, cracking behavior, crack pattern, deflection, variation of strains in the concrete and steel, collapse load and the modes of failure. The results of the test showed that, the repair materials applied on the various zones of the beams were able to restore more than 100% of the beams’ capacity and that FFSCM gave a better overall performance.

Restorative justice: Making amends, repairing relationships and healing

Since the late 1970s, there has been a significant expansion in techniques for using mediated interactions between offenders and those affected by their behaviour. This trend began with juvenile justice conferencing, family group conferencing and Indigenous sentencing circles. The umbrella term used to describe these techniques and processes is ‘restorative justice’ (‘RJ’ to its fans and practitioners).Two important catalysts for this expansion were an increased awareness of the marginalisation of victims in the criminal justice system, and concerns over climbing recidivism rates.

Incorporation of human recombinant tropoelastin into silk fibroin membranes with the view to repairing Bruch’s membrane

Bombyx mori silk fibroin membranes provide a potential delivery vehicle for both cells and extracellular matrix (ECM) components into diseased or injured tissues. We have previously demonstrated the feasibility of growing retinal pigment epithelial cells (RPE) on fibroin membranes with the view to repairing the retina of patients afflicted with age-related macular degeneration (AMD). The goal of the present study was to investigate the feasibility of incorporating the ECM component elastin, in the form of human recombinant tropoelastin, into these same membranes. Two basic strategies were explored: (1) membranes prepared from blended solutions of fibroin and tropoelastin; and (2) layered constructs prepared from sequentially cast solutions of fibroin, tropoelastin, and fibroin. Optimal conditions for RPE attachment were achieved using a tropoelastin-fibroin blend ratio of 10 to 90 parts by weight. Retention of tropoelastin within the blend and layered constructs was confirmed by immunolabelling and Fourier-transform infrared spectroscopy (FTIR). In the layered constructs, the bulk of tropoelastin was apparently absorbed into the initially cast fibroin layer. Blend membranes displayed higher elastic modulus, percentage elongation, and tensile strength (p < 0.01) when compared to the layered constructs. RPE cell response to fibroin membranes was not affected by the presence of tropoelastin. These findings support the potential use of fibroin membranes for the co-delivery of RPE cells and tropoelastin.

Building and Construction Trades Unions: Are They Built to Win?

[Excerpt] The evidence of labor's declining power in the economic and political arenas is increasingly clear. Despite the tenacious efforts of talented leaders over the past ten years, the labor movement has still failed to turn the proverbial cornet. Some labor leaders now believe that a dramatic change in strategic direction may be necessary to revitalize labor's fortunes. The emerging debate about labor's future touches every sector of the movement. The building and construction trades are no exception.

双面二维硅微条探测器的沾污失效分析及修复；Contamination failure analysis and repairing for double side two dimensional silicon microstrip detectors

硅微条探测器通过微电子工艺制作,易因沾污导致性能下降甚至失效;裸露的键合引线,也易因机械力形成隐性或显性失效。对上述现象的研究可用于修复、维护探测器并在设计和工艺流程中改进其性能。本文通过光学、电气手段分析其结构和制作工艺流程,根据沾污性质在不同条件下清洗探测器,中测后根据芯片图形、封装方式和电气要求修复探测器,最后采用同位素α能谱测试修复效果。对一块沾污后失效(无法加载偏压)的硅微条清洗后在大气环境,N面接地,P面加载负偏压条件下进行了测试,结果显示:170 V全耗尽,平均漏电流2.94μA,5.486 MeV的α峰能量分辨率约1.28%。失效键合所在条的另一面各条能谱观测到假峰,键合修复后消除。因沾污失效的硅微条探测器经过合适的清洗、修复,部分可以恢复性能,但清洗对表面和结构有损伤,须谨慎。另外,键合失效后,因信号不能引出导致的电荷积累会通过电容效应影响其它灵敏区。文章提示,探测器应存放于洁净,恒温,低湿度,避光,避强电磁干扰的环境,以提高能量和位置分辨率,并增加工作稳定性,延长使用寿命。

Repairing Learned Knowledge Using Experience

Explanation-based learning occurs when something useful is retained from an explanation, usually an account of how some particular problem can be solved given a sound theory. Many real-world explanations are not based on sound theory, however, and wrong things may be learned accidentally, as subsequent failures will likely demonstrate. In this paper, we describe ways to isolate the facts that cause failures, ways to explain why those facts cause problems, and ways to repair learning mistakes. In particular, our program learns to distinguish pails from cups after making a few mistakes.

Repairing wireless sensor network connectivity in damaged environments

A wireless sensor network can become partitioned due to node failure, requiring the deployment of additional relay nodes in order to restore network connectivity. This introduces an optimisation problem involving a tradeoff between the number of additional nodes that are required and the costs of moving through the sensor field for the purpose of node placement. This tradeoff is application-dependent, influenced for example by the relative urgency of network restoration. In addition, minimising the number of relay nodes might lead to long routing paths to the sink, which may cause problems of data latency. This data latency is extremely important in wireless sensor network applications such as battlefield surveillance, intrusion detection, disaster rescue, highway traffic coordination, etc. where they must not violate the real-time constraints. Therefore, we also consider the problem of deploying multiple sinks in order to improve the network performance. Previous research has only parts of this problem in isolation, and has not properly considered the problems of moving through a constrained environment or discovering changes to that environment during the repair or network quality after the restoration. In this thesis, we firstly consider a base problem in which we assume the exploration tasks have already been completed, and so our aim is to optimise our use of resources in the static fully observed problem. In the real world, we would not know the radio and physical environments after damage, and this creates a dynamic problem where damage must be discovered. Therefore, we extend to the dynamic problem in which the network repair problem considers both exploration and restoration. We then add a hop-count constraint for network quality in which the desired locations can talk to a sink within a hop count limit after the network is restored. For each new problem of the network repair, we have proposed different solutions (heuristics and/or complete algorithms) which prioritise different objectives. We evaluate our solutions based on simulation, assessing the quality of solutions (node cost, movement cost, computation time, and total restoration time) by varying the problem types and the capability of the agent that makes the repair. We show that the relative importance of the objectives influences the choice of algorithm, and different speeds of movement for the repairing agent have a significant impact on performance, and must be taken into account when selecting the algorithm. In particular, the node-based approaches are the best in the node cost, and the path-based approaches are the best in the mobility cost. For the total restoration time, the node-based approaches are the best with a fast moving agent while the path-based approaches are the best with a slow moving agent. For a medium speed moving agent, the total restoration time of the node-based approaches and that of the path-based approaches are almost balanced.

Trades Unions and the Transition away from 'actually existing unsustainability':From economic crisis to a new political economy beyond growth

Traditionally trades unions have accepted and promoted orthodox economic growth as a policy imperative. In recent years there has been a noticeable ‘greening’ of trade unions in relation to initiatives such as the ‘Green new deal’ and the creation of ‘green collar’ employment and the focus on a ‘just transition’ to a low carbon economy. Yet given the growing evidence of the negative impacts of economic growth in terms of environmental, resource and pollution impacts as well as the inability of economic growth to tackle (as opposed to managed) socio-economic inequality, it is timely to review the case for trades unions to fundamentally rethink the commitment to orthodox economic growth. That is, for trades unions to consider going beyond their current ‘green/sustainability’ strategies to consider more radical ‘post-growth’ policy positions. This chapter will explore some of the dimensions of a ‘post-growth’ trade union agenda by considering the evidence for going beyond growth from within the trade union movement (specifically looking at the International Labor Organization’s 2004 report on Economic Security, to internal union discussions around trades unionism and climate change) and external evidence ranging from Wilkinson and Pickett’s The Spirit Level (which suggests amongst other things that in the developed world what is needed is not economic growth but greater redistribution and lowering inequality – issues also of traditional interest to the Trades Union movement) to Tim Jackson’s Prosperity without Growth (which suggests that economic growth is ecologically unsustainable as well having passed a threshold beyond which it is contributing to human well-being in the developed world). As well as discussing the relationship between trades unionism and what may be called ‘green political economy’ (such as the ‘degrowth’ and ‘limits to growth’ perspectives) this chapter will also discuss the practical/policy implications of this ‘post-growth’ perspective in relation to trades unionism’s analysis of capitalism and its transformation in the context of a climate changed, carbon constrained world, including implications for ideas such as basic income, a shorter working week and what a trades unionism focused on how to achieve high quality of life within a low carbon context might look like.

Aspasing Out Metacaspases and Caspases: Proteases of Many Trades

Execution of programmed cell death (PCD) in nonmetazoan organisms is morphologically different from apoptotic PCD in animals and lacks a number of key molecular components of apoptotic machinery, including caspases. Yet protozoan, fungal, and plant cells exhibit caspase-like proteolytic activities, which increase in a PCD-dependent manner. This poses a question whether nonmetazoan organisms contain structurally dissimilar proteases that functionally substitute for caspases. Putative ancestors of caspases, metacaspases, are candidates for this role; however, their distinct substrate specificity raises doubts. The identification of a common biological target of caspases and metacaspases and previously unknown functions unrelated to cell death of metacaspases provide new food for thought.

US Dollar Carry Trades in the Era of 'Cheap Money'

In this paper, we employ a unique dataset of actual US dollar (USD) forward positions against a number of currencies taken by so-called Commodity Trading Advisors (CTAs). We investigate to what extent these positions exhibit a pattern of USD carry trading or other patterns of currency trading over the recent period of the ultra-loose US monetary policy. Our analysis indeed shows that USD positions against emerging market currencies are characterised by a pattern of carry trading. That is, the USD, as the lower yielding currency, is associated with short positions. The payoff distributions of these positions, moreover, are found to have positive Sharpe ratios, negative skewness and high kurtosis. On the other hand, we find that USD positions against other advanced country currencies have a pattern completely opposite to carry trading which is in line with uncovered interest parity trading; that is, the lower (higher) yielding currency is associated with long (short) positions.