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101.
This paper describes dust explosibility research in full-scale experimental mines and a 20-L laboratory chamber at the U.S. Bureau of Mines and in a 1-m3 laboratory chamber at Fike Corporation. The purpose of this research is to improve safety in mining and other industries that manufacture, process, or use combustible dusts. As part of this work, carbonaceous dusts with a wide range of volatilities and various particle size distributions were studied. Laboratory data on the minimum explosible concentrations of predispersed dusts were comparable to mine data for nominal dust loadings that were dispersed by the aerodynamic disturbance from a gas ignition zone. Recommendations are given on the limitations of small-scale testing such as “overdriving” by too strong of an ignitor. The effect of dust particle size on explosibility data is illustrated for coal and aluminum dusts. For both dusts, the finest sizes were the most hazardous. The inerting requirements for preventing explosions were also measured in both laboratory and large-scale systems. All the data show relatively good agreement between the laboratory and the large-scale tests.  相似文献   
102.
103.
Sustainable land use planning is crucial for realizing the aim of food security and for combating land degradation in the Sahel. A participatory land use planning workshop was organised in a village in the eastern region of Burkina Faso to investigate land use problems, their causes, effects and possible solutions. Participatory research tools and GIS were combined to get insight into possible conflicts or synergies between different land use options as mapped by different ethnic groups. Pictograms were used to locate alternative land use options on the map, after which they were digitised for analysis with GIS. The workshop confirms the importance of integrating scientific and local knowledge to develop concrete options for sustainable land use that fit to local realities and aspirations. Local people are knowledgeable about the driving forces behind land degradation, they take actions to combat the effects of degradation, and they have concrete ideas about alternative land use options. The use of GIS proved its added value in the participatory process of integrated land use planning. The maps that were produced also facilitate discussions between community members, researchers and government representatives at the regional level, both regarding current land use problems and regarding alternative options as perceived by the local population.  相似文献   
104.
Growth and liberalization of world trade have increased the risks of introduction of quarantine plant pests into importing countries. Import inspection of incoming commodities is a major tool for prevention of pest introductions related to world trade, but inspection capacities are limited. This article develops a theoretical and an empirical model for the optimal allocation of inspection effort for phytosanitary inspection of imported commodities when the inspecting agency has a limited capacity. It is shown that the optimal allocation of inspection effort equalizes marginal costs of pest introduction across risky commodity pathways. The numerical illustration finds the optimal allocation of inspection effort of chrysanthemum cuttings imported in the Netherlands. The numerical results suggest that ceteris paribus , greater inspection effort should be allocated to pathways whose inspection yields a greater reduction in the expected costs of pest introduction. The numerical results also suggest that import inspection has a high marginal benefit. In particular, we found that each additional euro of the inspection capacity decreases the expected costs of pest introduction from 18 to 49 euros, depending on the initial inspection capacity.  相似文献   
105.
Decentralization of land governance is expected to significantly improve land tenure security of small‐scale farmers in Africa, through ensuring better protection of their assets and reducing land‐related conflicts. This paper, however, cautions not to have too high expectations of transferring responsibilities for land administration and dispute resolution to local government bodies. Field research in Mbarara District in south‐western Uganda brings out how decentralization has limited impacts in terms of localizing land services provision. Nonetheless, local land governance has transformed in important ways, as decentralization adds to institutional multiplicity, and fuels competition among state and non‐state authorities, and about the rules they apply. Rather than strengthening local mechanisms for securing tenure, the reforms introduce new forms of tenure insecurity, fail to transform local conventions of dealing with land disputes and delegitimize local mechanisms for securing tenure. In practice, decentralization has had limited effects in securing tenure for the rural poor, yet reinforces the presence of the state at the local level in diverse ways.  相似文献   
106.
Research on location-based advertising (LBA) suggests that the merits of LBA lie in the fact that consumers can be targeted with location-congruent ads on their personal mobile devices. However, LBA consists of two underlying constructs: a mobile (vs. point-of-sales) advertising medium and location congruency (vs. location incongruency). This study aims to disentangle these underlying constructs by showing that they differentially affect the efficacy of an ad. Using a virtual reality lab experiment, this study shows that location-congruent ads result in increased choice for the target brand as compared to location-incongruent ads, independent of medium type. However, in location-incongruent situations, mobile ads attracted more attention than point-of-sales display ads. The advantages of LBA thus do not seem to emanate from medium type, but rather from the congruency between the ad and product location. When the ad is received at a different location than the product, the mobile medium is able to enhance consumers' ad attention.  相似文献   
107.
Eating and exercising behaviour are both characterized by immediate and future consequences. Consequently, consideration of these consequences (i.e. time orientation) predicts eating and exercising behaviour. We investigate whether construal level acts as an underlying mechanism of these relations. Students (N = 101) completed measures of consideration of immediate and future consequences (i.e. CFC‐food and CFC‐exercise), construal level, eating and exercising behaviour and preferences. For self‐reported eating and exercising behaviour, only direct effects of consideration of immediate and future consequences were found. For eating preferences, however, there was evidence of an indirect effect through construal level. A stronger tendency to consider future consequences led to a stronger preference for utilitarian (as compared with hedonic) food products through a more abstract construal level. All in all, construal level partially explains the differential relations between consideration of immediate and future consequences and eating and exercising behaviour and preferences.  相似文献   
108.
109.
Scholars in our field, Operations and Supply Chain Management (OSCM), are under high pressure to show research productivity. At most schools, this productivity is measured by the number of journal articles published. One possible response to such pressure is to improve research efficiency: publishing more journal articles from each data collection effort. In other words, using one dataset for multiple publications. As long as each publication makes a sufficient contribution, and authors ensure transparency in methods and consistency across publications, generating more than one publication from one data collection effort is possible. The aim of this Notes and Debates article, however, is to draw attention to inappropriate reuse of empirical data in OSCM research, to explain its implications and to suggest ways in which to promote research quality and integrity. Based on two cases of extensive data reuse in OSCM, eighteen problematic practices associated with the reuse of data across multiple journal articles are identified. Recommendations on this issue of data reuse are provided for authors, reviewers, editors and readers.  相似文献   
110.
The organizational design literature strongly supports the notion of “structure follows strategy”, and suggests that a misfit between the two has a negative effect on performance. Building on this line of argument, we examine to what extent the (mis)fit between purchasing strategy and purchasing structure impacts purchasing performance. We focus on cost and innovation purchase category strategies, and examine how the deviation from an ideal purchasing structure defined along three dimensions (centralization, formalization, and cross-functionality) impacts purchasing performance. Analysing data collected from 469 firms in ten countries, we demonstrate that a strategy-structure misfit negatively impacts purchasing performance in both cost and innovation strategies. We also find that purchasing proficiency is a mediator in this relationship between misfit and performance. Our findings aid managerial decision making by empirically validating the necessity of having the right purchasing structure for successfully executing different purchasing strategies.  相似文献   
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