Use of Nutshells as Fillers in Polymer Composites

Nutshells are agricultural waste products that can be procured at relatively low cost. In this work we examined the possibility of using these biodegradable materials as fillers in poly(lactic acid) and low density polyethylene. The nutshells were ground into powder, blended with the polymer, and then injection molded with final weight varying from 10 to 40 weight %. The mechanical and thermal properties of the composites were then studied. In general, the addition of fillers caused reductions in mechanical properties to varying extents, but thermal properties were only slightly affected. The use of maleic anhydride and peroxide with the fillers had a negative effect on poly(lactic acid) but a slightly positive effect on the stiffness of polyethylene. The results suggested that polymer-nutshell composites may be usable in applications where cost is a concern and where some reductions in mechanical properties are acceptable.     

Decentralization and people's participation in conservation: a comparative study from the Western Terai of Nepal

Nepal formally embarked on decentralized participatory conservation programmes in 1990. To assess who participates in and benefits from such programmes, stratified random questionnaire surveys of 234 households and interviews with 29 user group chairs were conducted in the buffer zones of two protected areas of the Nepalese Terai: Bardia National Park and Suklaphanta Wildlife Reserve. The Poisson regression shows that gender, education, household affluence, and conservation attitudes were significant predictors of people's participation in decentralized conservation programmes, while family size, ethnicity and resource dependency were not. The benefits of participation outweighed the costs based on respondents' estimates. The performance of grassroots organizations and levels of participation were correlated. Nepal's decentralized participatory conservation has achieved efficiency, relative equity and effectiveness to some extent. Yet the central government should devolve more power to local communities to sustain the achievements as well as to provide more equitable benefits to residents to ensure the effectiveness and sustainability of conservation programmes.     

Understanding “communication gaps” among personnel in high-risk workplaces from a dialogical perspective

Our primary aim in this paper is to argue for a discourse analytical take on questions of how risk and safety are managed by personnel in high-risk workplaces, with a special focus on constructions of “us” and “them”. Thus, we approach the same issue investigated in many other studies, i.e., diverging safety-related understandings between people representing various occupational groups. We choose to examine so-called communication gaps as they are “talked into being” in discourse, meaning that we treat them as primarily socially constructed. A case analysis based on interviews will be used to illustrate how we can understand this phenomenon from a communicative perspective inspired by Linell’s (1998a) dialogue theory. While previous discourse and safety culture research emphasizes broad patterns and differences between entire professions and departments, we argue that researchers should hesitate to reinforce the notion of homogeneous groups. Instead, there is great value in demonstrating collective social construction processes and commonalities so as to facilitate inter-group solidarity and possibly productive change.     

Water-Quality Monitoring and Biological Integrity Assessment in the Indian River Lagoon, Florida: Status, Trends, and Loadings (1988–1994)

a production in the central, south central, and the south segments of the lagoon. In a system as large and complex as the lagoon, N and P limitations are potentially subject to significant spatial and temporal variability. Total Kjeldahl nitrogen (TN) was higher in the north (1.25 mg/liter) and lower in the south (0.89 mg/liter). The reverse pattern was observed for total P (TP), i.e., lowest in the north (0.03 mg/liter) and highest at the south (0.14 mg/liter) ends of the IRL. This increased P concentration in the SIRL appears to have a significantly large effect on chlorophyll a production compared with the other segments, as indicated by stepwise regression statistics. This relationship can be expressed as follows: South IRL [chlorophyll a] =−8.52 + 162.41 [orthophosphate] + 7.86 [total nitrogen] + 0.38 [turbidity]; R ²= 0.98**.     

IMPLICATIONS OF A DRAWDOWN OF THE SNAKE-COLUMBIA RWER ON BARGE TRANSPORTATION1

ABSTRACT: The listing of the Snake-Columbia River salmon under the Endangered species Cut will lead to a set of river management changes aimed at species recovery. One measure almost certain to be implemented is a periodic river drawdown. A drawdown will speed fish migration downriver but will also temporarily close the river to barge transportation. Grain shippers in the region rely on the barge carriage to move a significant share of annual production to export elevators on the Lower Columbia. A number of other bulk commodities utilize barges as well. This study outlines the aggregate and distributional economic implications of a suspension of barge transportation resulting from a river drawdown.     

The global troposphere: Biogeochemical cycles,chemistry, and remote sensing

The chemical composition of the troposphere is controlled by various biogeochemical cycles that couple the atmosphere with the oceans, the solid Earth and the biosphere, and by atmospheric photochemical/chemical reactions. These cycles and reactions are discussed and a number of key questions concerning tropospheric composition and chemistry for the carbon, nitrogen, oxygen and sulfur species are identified. Next, we review various remote sensing techniques and instruments capable of measuring and monitoring tropospheric species from the ground, aircraft and space to address some of these key questions. We also consider future thrusts in remote sensing of the troposphere.