853 resultados para environmental implications of mining closure


Relevância:

100.00% 100.00%

Publicador:

Resumo:

This thesis is composed of three life-cycle analysis (LCA) studies of manufacturing to determine cumulative energy demand (CED) and greenhouse gas emissions (GHG). The methods proposed could reduce the environmental impact by reducing the CED in three manufacturing processes. First, industrial symbiosis is proposed and a LCA is performed on both conventional 1 GW-scaled hydrogenated amorphous silicon (a-Si:H)-based single junction and a-Si:H/microcrystalline-Si:H tandem cell solar PV manufacturing plants and such plants coupled to silane recycling plants. Using a recycling process that results in a silane loss of only 17 versus 85 percent, this results in a CED savings of 81,700 GJ and 290,000 GJ per year for single and tandem junction plants, respectively. This recycling process reduces the cost of raw silane by 68 percent, or approximately $22.6 and $79 million per year for a single and tandem 1 GW PV production facility, respectively. The results show environmental benefits of silane recycling centered around a-Si:H-based PV manufacturing plants. Second, an open-source self-replicating rapid prototype or 3-D printer, the RepRap, has the potential to reduce the environmental impact of manufacturing of polymer-based products, using distributed manufacturing paradigm, which is further minimized by the use of PV and improvements in PV manufacturing. Using 3-D printers for manufacturing provides the ability to ultra-customize products and to change fill composition, which increases material efficiency. An LCA was performed on three polymer-based products to determine the CED and GHG from conventional large-scale production and are compared to experimental measurements on a RepRap producing identical products with ABS and PLA. The results of this LCA study indicate that the CED of manufacturing polymer products can possibly be reduced using distributed manufacturing with existing 3-D printers under 89% fill and reduced even further with a solar photovoltaic system. The results indicate that the ability of RepRaps to vary fill has the potential to diminish environmental impact on many products. Third, one additional way to improve the environmental performance of this distributed manufacturing system is to create the polymer filament feedstock for 3-D printers using post-consumer plastic bottles. An LCA was performed on the recycling of high density polyethylene (HDPE) using the RecycleBot. The results of the LCA showed that distributed recycling has a lower CED than the best-case scenario used for centralized recycling. If this process is applied to the HDPE currently recycled in the U.S., more than 100 million MJ of energy could be conserved per annum along with significant reductions in GHG. This presents a novel path to a future of distributed manufacturing suited for both the developed and developing world with reduced environmental impact. From improving manufacturing in the photovoltaic industry with the use of recycling to recycling and manufacturing plastic products within our own homes, each step reduces the impact on the environment. The three coupled projects presented here show a clear potential to reduce the environmental impact of manufacturing and other processes by implementing complimenting systems, which have environmental benefits of their own in order to achieve a compounding effect of reduced CED and GHG.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Maintaining the readiness U.S. nuclear weapons stockpile is a fundamental pillar of American defense policy. The biggest issue facing the national laboratories that are charged with this mission is replenishing the highly skilled and specialized manpower that is necessary for this task. This lecture presents both physics and science policy questions that must be answered. It also presents employment opportunities for young scientists and engineers.

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Like tumor metastases, endometriotic implants require neovascularization to proliferate and invade into ectopic sites within the host. Endometrial tissue, with its robust stem cell populations and remarkable regenerative capabilities, is a rich source of proangiogenic factors. Among the most potent and extensively studied of these proteins, vascular endothelial growth factor has emerged as a critical vasculogenic regulator in endometriosis. Accordingly, angiogenesis of the nascent endometriotic lesion has become an attractive target for novel medical therapeutics and strategies to inhibit vascular endothelial growth factor action. Vascular endothelial growth factor gene regulation in endometrial and endometriosis cells by nuclear receptors, other transcription factors, and also by infiltrating immune cells is emphasized. New data showing that oxidative and endoplasmic reticulum stress increase vascular endothelial growth factor expression are provided. Finally, we review the clinical implications of angiogenesis in this condition and propose potential antiangiogenic therapies that may become useful in the control or eradication of endometriotic lesions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

BACKGROUND: Different stents in infrainguinal arteries have recently been associated with stent fractures and unfavorable clinical outcome, although data is limited regarding fractures of the Xpert selfexpanding nitinol stent. Thus, purpose of the present investigation was to evaluate its incidence and clinical implications in lower limb arteries. PATIENTS AND METHODS: Fifty-three consecutive patients (53 limbs) with peripheral arterial disease underwent secondary Xpert stent implantation due to suboptimal primary balloon angioplasty (PTA). Median age was 76 years. Stent fractures were evaluated by plain X-ray at median follow-up of 16 months. Stent patency was assessed by duplex ultrasound and sustained clinical improvement was defined as improvement of the ABI of > or = 0.10 together with improvement of at least one Rutherford class above the baseline finding throughout follow-up. RESULTS: Median length of femoropopliteal and infrapopliteal lesion was 3.0 and 2.3 cm, respectively. Sixtyfive stents were implanted in 43 limbs with femoropopliteal and 10 stents in 10 limbs with infrapopliteal lesion, respectively. Stent fractures occurred in 3 of 43 limbs (7.0%) of patients with femoropopliteal lesion with stent-based fracture rate of 4.6%. All fractured stents showed multiple struts fractures and occurred in the distal and middle superficial femoral artery. No stent fracture was observed in infrapopliteal lesions. The fractured stents were not associated with any clinical deterioration. Sustained clinical improvement was 71.0% and 54.6% for femoropopliteal and infrapopliteal lesions, respectively. Stent patency assessed by duplex was 65.2 and 63.9% for femoropopliteal and infrapopliteal lesions, respectively. CONCLUSIONS: Fractures of the Xpert stent were seldom and not associated with unfavorable clinical outcome at midterm follow-up.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Several commentators have expressed disappointment with New Labour's apparent adherence to the policy frameworks of the previous Conservative administrations. The employment orientation of its welfare programmes, the contradictory nature of the social exclusion initiatives, and the continuing obsession with public sector marketisation, inspections, audits, standards and so on, have all come under critical scrutiny (c.f., Blyth 2001; Jordan 2001; Orme 2001). This paper suggests that in order to understand the socio-economic and political contexts affecting social work we need to examine the relationship between New Labour's modernisation project and its insertion within an architecture of global governance. In particular, membership of the European Union (EU), International Monetary Fund (IMF) and World Trade Organisation (WTO) set the parameters for domestic policy in important ways. Whilst much has been written about the economic dimensions of 'globalisation' in relation to social work rather less has been noted about the ways in which domestic policy agenda are driven by multilateral governance objectives. This policy dimension is important in trying to respond to various changes affecting social work as a professional activity. What is possible, what is encouraged, how things might be done, is tightly bounded by the policy frameworks governing practice and affected by those governing the lives of service users. It is unhelpful to see policy formulation in purely national terms as the UK is inserted into a network governance structure, a regulatory framework where decisions are made by many countries and organisations and agencies. Together, they are producing a 'new legal regime', characterised by a marked neo-liberal policy agenda. This paper aims to demonstrate the relationship of New Labour's modernisation programme to these new forms of legality by examining two main policy areas and the welfare implications they are enmeshed in. The first is privatisation, and the second is social policy in the European Union. Examining these areas allows a demonstration of how much of the New Labour programme can be understood as a local implementation of a transnational strategy, how parts of that strategy produce much of the social exclusion it purports to address, and how social welfare, and particularly social work, are noticeable by their absence within policy discourses of the strategy. The paper details how the privatisation programme is considered to be a crucial vehicle for the further development of a transnational political-economy, where capital accumulation has been redefined as 'welfare'. In this development, frameworks, codes and standards are central, and the final section of the paper examines how the modernisation strategy of the European Union depends upon social policy marked by an employment orientation and risk rationality, aimed at reconfiguring citizen identities.The strategy is governed through an 'open mode of coordination', in which codes, standards, benchmarks and so on play an important role. The paper considers the modernisation strategy and new legality within which it is embedded as dependent upon social policy as a technology of liberal governance, one demonstrating a new rationality in comparison to that governing post-Second World War welfare, and which aims to reconfigure institutional infrastructure and citizen identity.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

VHB-JOURQUAL represents the official journal ranking of the German Academic Association for Business Research. Since its introduction in 2003, the ranking has become the most influential journal evaluation approach in German-speaking countries, impacting several key managerial decisions of German, Austrian, and Swiss business schools. This article reports the methodological approach of the ranking’s second edition. It also presents the main results and additional analyses on the validity of the rating and the underlying decision processes of the respondents. Selected implications for researchers and higher-education institutions are discussed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper investigates the relationship between annual report disclosure, market liquidity, and capital cost for firms registered on the Deutsche Börse. Disclosure is comprehensively measured using the innovative Artificial Intelligence Measurement of Disclosure (AIMD). Results show that annual report disclosure enhances market liquidity by changing investors’ expectations and inducing portfolio adjustments. Trading frictions are negatively associated with disclosure. The study provides evidence for a capital-costreduction effect of disclosure based on the analysis of investors’ return requirements and market values. Altogether, no evidence is found that the information processing at the German capital market is structurally different from other markets.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Is it good or bad for senior executives to have strong interpersonal ties to the CEO? We argue that a strong relationship with the CEO raises the likelihood that a top manager stays in office or makes an upward career move when the CEO leaves office voluntarily. At the same time, such interpersonal ties also reinforce the negative spillover effects of a dismissal of the CEO on the career prospects of the manager concerned. Our empirical analysis lends support to both arguments. We contribute to managerial succession research by underlining the ambivalence of interpersonal ties within top management teams.