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991.
Summary Changes in the density of beech scale infestation (Cryptococcus fagisuga) of a mature beech stand (Fagus sylvatica) were investigated after gap-cutting in limed and unlimed areas bordering on the gaps and in untreated areas over a 5-year period. Parallelly the concentrations of sucrose, protein amino acids, and procyanidins were examined in the inner and outer bark of non-infested beech trees and beeches infested by beech scale.Irrespective of liming in the areas bordering on the gaps the proportion of beech trees with increasing beech scale infestation was significantly higher, the proportion of beeches with diminishing infestation was significantly lower than in the untreated control areas. Trees with the same infestation tendency occurred in clusters.Physiological defence reactions in the inner and outer bark of the infested beech trees were registrated as an increase in the procyanidin content and a decrease in the protein amino acid content. A change in the outer bark—inner bark—ratio of the infested beech trees showed a transfer of compounds between the inner and outer bark. During the period of observation long-lasting shifts occurred in the pattern of compounds of the bark irrespective of actual infestation intensity.  相似文献   
992.
The main objective of the study was to calculate net atmospheric impacts for wood production and utilization in Finnish boreal forest conditions. Net atmospheric impacts were calculated by comparing net CO2 exchanges of the wood production and utilization to the reference management regime. Net CO2 exchanges were simulated with a life cycle assessment (LCA) tool for a Scots pine (Pinus sylvestris L.) stand (MT, Myrtillys-type) in central Finland (Joensuu region, 62°39 N, 29°37 E) over two consecutive rotation periods (100?+?100 years/200 years). Net atmospheric impacts were calculated both for sawn timber and pulpwood, and expressed in kgCO2m?3. According to the results, the production of pulp and sawn timber produced emissions of 0.20 and 0.59 kgCO2m?3 over the 200-year period, respectively, when the unmanagement regime was used as the reference management regime. When 50 % of the processing waste of timber was accounted as an instant emission to the atmosphere, the atmospheric impact increased to 0.55 kgCO2m?3 in pulpwood and to 1.27 kgCO2m?3 in sawn timber over the 200 year period. When turnover rates of sawn timber in the technosystem were decreased by 30 % and the share of energy use was decreased to 30 %, the atmospheric impact decreased by 17 % and 4 % for pulpwood and sawn timber, respectively, compared to the default wood degradation and energy use of 50 %. The utilized LCA approach provided an effective tool for approaching net atmospheric impacts originating from the ecosystem carbon (C) flows and variable wood utilization. Taking the ecosystem production and utilization of wood (i.e. degradation of technosystem C stock) into account, in terms of net CO2 exchange, the mitigation possibilities of wood compared to other products can be accounted for more precisely in the future and C sequestration credited more specifically for a certain wood product.  相似文献   
993.
The selective introduction of compressive residual stresses is gaining increasing importance as design tool in today's manufacturing process chains. Manufacturing processes such as shot peening or hydraulic autofrettage are used to improve the surface integrity, and hence the fatigue life of the components. However, measuring the corresponding residual stress depth profiles is a challenging task as the results will always include the manufacturing and preparation history of the components. In this paper, results of residual stress measurements with X-ray diffraction and optical hole-drilling after autofrettage and sample preparation are presented and compared to a finite element analysis for two representative geometries. The presented approach can be used to predict the influence of the mandatory sample preparation procedure. As a consequence, the effectiveness of the manufacturing process to improve the surface integrity can be predicted more precisely and wrong interpretations of the measured residual stress depth profiles can be avoided.  相似文献   
994.
Human factors (HF) in creating and managing safety in complex systems is a continuous topic of research and discussion. In the aviation organisation under study here, an HF expert had started work in a newly created position one and a half years prior to the study. The aim of the study was to find out if HF was seen as a safety creating factor and what the conceptions of HF were in regard to the theoretical developments in the field. These topics were studied in order to determine the most effective means of implementing HF-work within the organisation. Two manager groups (upper and middle management) were targeted as subjects of the study due to their crucial role in developing working culture. Twenty-one managers were interviewed from nine units that represented three operational environments (radar units with heavy traffic, combined civil/military units and procedural air traffic control units, including airport operations. Managers were found to have disjointed and vague conceptions of HF and a lack of shared vision or strategy regarding HF. Some managers lacked an appropriate conception of HF. The present situation can prevent the organisation from utilizing HF competence in maintaining and developing the safety of services. Conceptions were most up-to-date at units, where outside pressures for change had forced managers to take HF issues into account in their operational environments. While the long-term implementation of HF faces considerable challenges, the article gives several proposals for organisational structures that support a more effective realization of HF.  相似文献   
995.
We describe the development of an integrated assessment model which evaluates redevelopment options of large contaminated brownfields and we present the application of the model in a case study. Aiming to support efficient and sustainable revitalization and communication between stakeholders, the presented assessment model integrates three pinnacles of brownfield revitalization: (i) subsurface remediation and site preparation costs, (ii) market-oriented economic appraisal, and (iii) the expected contribution of planned future land use to sustainable community and regional development. For the assessment, focus is set on the early stage of the brownfield redevelopment process, which is characterized by limited data availability and by flexibility in land use planning and development scope. At this stage, revealing the consequences of adjustments and alterations in planning options can foster efficiency in communication between the involved parties and thereby facilitates the brownfield revitalization process. Results from the case-study application indicate that the integrated assessment provides help in the identification of land use options beneficial in both a sustainable and an economical sense. For the study site it is shown on one hand that brownfield redevelopment is not automatically in line with sustainable regional development, and on the other hand it is demonstrated that additional contributions to sustainability are not intrinsically tied to increased costs.  相似文献   
996.
A semi-commercial 10 MWth chemical looping combustion (CLC) plant for power production is proposed as a next scale demonstration plant after successful operation of a 120 kW CLC pilot rig. The design criteria for the CLC boiler are derived from the experience obtained from the CLC pilot rig at Vienna University of Technology. The IPSEpro simulation environment is chosen for implementation of the process flow sheet of the CLC power plant. A single pressure steam cycle is suggested for this small scale demonstration plant. Heat exchangers and a five-stage steam turbine are arranged. Basic design parameters of the power plant are derived from detailed mass and energy investigations and discussed. It turns out that the net electric efficiency of such a small scale plant can be expected to be in the range of 32.5–35.8%. However, a demonstration of CLC at such a scale is necessary in order to gain confidence in more sophisticated CLC power generation concepts at larger scale.  相似文献   
997.
998.
This paper examines the key design mechanisms of existing and proposed cap-and-trade markets. First, it is shown that the hybrid systems under investigation (price floor using a minimum price guarantee, price collar, allowance reserve, options offered by the regulator, and offset relaxation) can be decomposed into a combination of an ordinary cap-and-trade scheme with European- or American-style call and put options. Then, we quantify and discuss the advantages and disadvantages of the proposed hybrid schemes by investigating whether pre-set objectives (enforcement of permit price bounds and reduction of the compliance costs for relevant companies) can be accomplished while maintaining the original environmental targets. Plain vanilla options are proposed as an alternative that reconciles the otherwise conflicting policy objectives.  相似文献   
999.
This article reports on the second Young Environmental Scientists Meeting that was hosted from 28 February to 2 March 2011 by the Institute for Environmental Research at RWTH Aachen University, Germany. This extraordinary meeting was again initiated and organized by the Student Advisory Council under the umbrella of Society of Environmental Toxicology and Chemistry Europe. A movie about the meeting and the abstracts of poster and platform presentations are freely available as supplemental material of this article.  相似文献   
1000.
The possible integration of different sexual ornaments into a composite system, and especially the information content of such ornament complexes, is poorly investigated. Many bird species display complex plumage coloration, but whether this represents one integrated or several independent sexual traits can be unclear. Collared flycatchers (Ficedula albicollis) display melanised and depigmented plumage areas, and the spectral features (brightness and UV chroma) of these are correlated with each other across the plumage. In a 5-year dataset of male and female plumage reflectance, we examined some of the potential information content of integrated, plumage-level colour attributes by estimating their relationships to previous and current year body condition, laying date and clutch size. Females were in better condition the year before they became darker pigmented, and males in better current year condition were also darker pigmented. Female pigment-based brightness was positively, while male structurally based brightness was negatively related to current laying date. Finally, the overall UV chroma of white plumage areas in males was positively associated with current clutch size. Our results show that higher degree of pigmentation is related to better condition, while the structural colour component is associated with some aspects of reproductive investment. These results highlight the possibility that correlated aspects of a multiple plumage ornamentation system may reflect together some aspects of individual quality, thereby functioning as a composite signal.  相似文献   
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