顶板抽采巷瓦斯抽采影响因素研究

通过对谢桥矿1151（3）顶板高抽巷瓦斯抽采效果的观测,考察了瓦斯抽采量、瓦斯抽采率和抽采瓦斯浓度随顶板高抽巷的位置、工作面推进速度、工作面距离开切眼的位置等的变化关系,得到了一些有一有益的结论,对今后的瓦斯抽采具有指导意义。     

井下瓦斯抽采管网监控系统在古汉山矿的应用

为了保证采掘工作面瓦斯抽采达标评判的准确性和实现瓦斯抽采管网的连续监测,通过KJ370瓦斯抽采管网监控系统对井下各采掘地点进行在线监测,认为KJ370瓦斯抽采管网监控系统达到了预期要求,实现了管网在线监控、管路异常分析和瓦斯抽采效果评判的准确性。     

巷抽方法的应用与效果分析

施工穿层预抽钻孔是目前煤矿治理瓦斯行之有效的主要手段.如何提高瓦斯抽采效果,这是高瓦斯矿井在瓦斯治理方面亟待解决的问题.我矿应用巷抽方法抽采瓦斯,大量节约了成本,并且大幅度提升采量与抽采率.     

高瓦斯采煤工作面高抽巷瓦斯抽采技术改进实践

高抽巷抽采瓦斯是生产矿井治理工作面瓦斯的重要手段,文章介绍了高抽巷抽采技术实践,并有所创新,节约的成本,提高了初采期间的抽放效果。     

低浓度抽采钻孔堵漏技术研究

针对焦煤集团九里山矿抽采钻孔漏气、抽采效果差,提出了低浓度抽采钻孔堵漏技术,现场试验了两种堵漏方法,堵漏后,钻孔抽采浓度平均由12.4%提高到33.5%,浓度提高了2.7倍;单孔平均瓦斯抽采纯量由19m3/d 提高到62m3/m,提高了3.3倍.     

囊袋式两端自堵封孔工艺实验效果研究——以焦煤集团中马村矿为例

抽采钻孔封孔质量的优劣直接影响着煤矿回采工作面瓦斯抽采效果。针对国内瓦斯抽采浓度普遍偏低的现状,特引进囊袋式两端自堵封孔工艺以提高瓦斯抽采功效及浓度。本文以焦煤集团中马村矿为例,通过实验探索该工艺在增强瓦斯抽采效果上的优势。     

高瓦斯采煤工作面高抽巷瓦斯抽采技术改进实践

高抽巷抽采瓦斯是生产矿井治理工作面瓦斯的重要手段，文章介绍了高抽巷抽采技术实践，并有所创新，节约的成本，提高了初采期间的抽放效果。     

水力冲孔增透技术在揭煤中的应用

在揭煤前措施孔施工过程中采取水力冲孔，增加煤层透气性，提高抽采钻孔的抽采影响半径，提高钻孔的抽采浓度与抽采效果，确保安全生产。     

近距离煤层群下保护层开采卸压瓦斯抽采技术

针对瓦斯抽采技术研究方面存在的问题,对瓦斯抽采方法分类、近距离煤层群卸压瓦斯抽采方法筛选进行分析,并经过实例分析,取得了良好的应用效果。     

新型瓦斯抽采自动负压放水器改造研究

目前市场上的自动负压放水器很难满足抽采管路放水的要求,西山煤电东曲矿对此进行创新,发明了新型瓦斯抽采自动负压放水器,改善了瓦斯抽采效果,解决了瓦斯超限,实现矿井安全生产。     

Workfare,welfare, agency,and well-being

Workfare programs are state-instituted programs that require able-bodied persons with children of school age who wish to claim welfare payments to participate in job training programs, and, eventually, to enter the work force. The philosophy of workfare is based on the value of work and the goal of self-determination. However, as a mandatory program for welfare recipients, workfare requires of those recipients certain duties which, according to those who challenge workfare, interfere with the freedom to choose what one will do with one's life. Whether some form of workfare will be adopted as part of our national welfare system remains to be seen. What the debate about such a program suggests is that welfare, in itself, by ignoring the necessity of security and education for full human agency, neither satisfies basic needs nor prepares its recipients for any life other than that of dependency. With all its difficulties workfare nevertheless presents an alternative to welfare that, at least in theory, more closely identifies its purpose with the values of our society.     

Externalities, Indivisibility, Nonreplicability, and Agglomeration

In this paper we argue that the impact of external scale economies and diseconomies on city size is not nearly as clear-cut as it is tacitly believed in urban economics. Similarly, city-size distortions are not caused by externalities alone. Indivisibility and nonreplicability, which prevent establishing the “right” number of cities, may represent a source for city-size distortions which can be stronger than the standard resource misallocation resulting from external scale economies and diseconomies. It follows that a direct population dispersion policy is not just an inferior substitute to Pigouvian taxes and subsidies but rather a useful complement.     

Streets, Malls, and Supermarkets

We develop a model of competition between shopping centers, comparing competitive outcomes in three alternative modes of retail organization, namely: streets (in which neither developers or retailers internalize agglomeration effects between products); malls (in which developers internalize); and supermarkets (in which both developers and retailers internalize). For a fixed number of centers: (i) converting streets to malls intensifies developer (but not retailer) competition, which increases product range (i.e., the number of shops built by the developers) and consumer surplus, reduces profits, and has ambiguous effects on welfare; (ii) converting streets to supermarkets intensifies retailer and developer competition, has ambiguous effects on product range (number of shops), reduces profits, and increases social welfare. With free entry both conversions reduce the number of centers and, if there is excess entry, conversion to supermarkets (but not malls) unambiguously increases welfare.     

Profit,productivity, and profit-sharing

This study is an investigation of the effect of profit-sharing on labor productivity. When monitoring labor performance is costly for management, a regular wage/salary contract is insufficient to induce profit-maximizing behavior from the worker. The authors demonstrate that when this profit-maximizing behavior can be induced only through profit-sharing, a linear profit-sharing program will increase productivity and the welfare of both management and labor. The benefit from profit-sharing is increasing up to the point where the utility of additional income is offset by the negative utility of extraordinary effort (working harder or providing higher quality work). The income effect, i.e., the change in negative utility of extraordinary effort given a change in income, can potentially either increase or decrease the point at which the income-effort tradeoff-reaches zero.     

Packaging,business, and society

The objective of this paper is to present the impact of packaging material on sustainability. The article analyzes the size of the problem that arises from the use of packaging and the effect of various types of packaging material on waste management. The data on solid waste from the United States and the European Union reinforce that the problem is not only huge but also requires immediate attention. The research found that paying attention to packaging has the potential to improve economic, environmental, and social sustainability. Reducing packaging in supply chains improves profitability for organizations, reduces environmental impact, and helps societies in lowering the cost of disposal. The cost of packaging materials and the costs of disposal and landfill, are borne by the end consumers. Suggested approaches to minimizing the generation of packaging waste include concerted efforts for reducing packaging throughout supply chains where elimination of packaging is not feasible, the formation of a global policy on the use and disposal of packaging materials, and educating consumers.     

Delegation, Committees, and Managers

Attempts to economize on decision-making time imply that groups of peers may delegate authority to a small committee of managers even though this means that the information and preferences of the uninvolved players are neglected. Decisions are more likely to be delegated to players with better information and more representative preferences. The possibility of ex post protests may force managers to take the preferences of others into account but may also give them incentives to ignore their private information. The argument may explain employees' willingness to let bosses decide, and thus throw some light on the theory of the firm.     

Indifference,indecision, and coin-flipping

This article operationalizes a non-empty relation as implied if strict preference and indifference jointly do not completely order the choice set. Specifically, indecision is operationalized as a positive preference for delegating choice to a least predictable device.     

Debt,equity, and information

Most firms issue financial assets such as debt or equity (e.g. bonds or stock) to outside investors. While these financial assets differ greatly in their characteristics, their diversity has received little attention in the literature. Filling this important gap in the literature, this paper views debt and equity as financial contracts, and asks why they are optimal instead of other financial contracts. By endogenizing the bankruptcy process, this paper shows how debt and equity arise as a consequence of an optimal allocation of cash-flow rights and monitoring rights, and how equity leads to dividend signaling.