Vocational rehabilitation programmes: A financial appraisal

This paper seeks to evaluate the efficacy of rehabilitation programs in facilitating injured workers' return to work. A major methodological problem with such investigations is the inability of the analyst to observe the counter-factual, i.e. the outcome had the worker's compensation claimant not received rehabilitation services. In this paper the results are reported of an empirical investigation of the effectiveness of rehabilitation programs undertaken by 503 injured workers. An internal control group of injured workers who fail to complete rehabilitation programs is used to assess the impact of rehabilitation. Multivariate statistical techniques are used to hold injury and socio-economic characteristics constant, and to arrive at an estimate of the probability of a successful return to work. This probability estimate is then used to ‘weight’ the potential cost saving. Our findings are that every $1 spent on rehabilitation services yields a reduction of system costs of $2.31.     

Stochastical analysis of surfactant-enhanced remediation of denser-than-water nonaqueous phase liquid (DNAPL)-contaminated soils

Stochastical analysis was performed to assess the effect of soil spatial variability and heterogeneity on the recovery of denser-than-water nonaqueous phase liquids (DNAPL) during the process of surfactant-enhanced remediation. UTCHEM, a three-dimensional, multicomponent, multiphase, compositional model, was used to simulate water flow and chemical transport processes in heterogeneous soils. Soil spatial variability and heterogeneity were accounted for by considering the soil permeability as a spatial random variable and a geostatistical method was used to generate random distributions of the permeability. The randomly generated permeability fields were incorporated into UTCHEM to simulate DNAPL transport in heterogeneous media and stochastical analysis was conducted based on the simulated results. From the analysis, an exponential relationship between average DNAPL recovery and soil heterogeneity (defined as the standard deviation of log of permeability) was established with a coefficient of determination (r2) of 0.991, which indicated that DNAPL recovery decreased exponentially with increasing soil heterogeneity. Temporal and spatial distributions of relative saturations in the water phase, DNAPL, and microemulsion in heterogeneous soils were compared with those in homogeneous soils and related to soil heterogeneity. Cleanup time and uncertainty to determine DNAPL distributions in heterogeneous soils were also quantified. The study would provide useful information to design strategies for the characterization and remediation of nonaqueous phase liquid-contaminated soils with spatial variability and heterogeneity.     

The influence of personal protection equipment,occupant body size,and restraint system on the frontal impact responses of Hybrid III ATDs in tactical vehicles

Objective: Although advanced restraint systems, such as seat belt pretensioners and load limiters, can provide improved occupant protection in crashes, such technologies are currently not utilized in military vehicles. The design and use of military vehicles presents unique challenges to occupant safety—including differences in compartment geometry and occupant clothing and gear—that make direct application of optimal civilian restraint systems to military vehicles inappropriate. For military vehicle environments, finite element (FE) modeling can be used to assess various configurations of restraint systems and determine the optimal configuration that minimizes injury risk to the occupant. The models must, however, be validated against physical tests before implementation. The objective of this study was therefore to provide the data necessary for FE model validation by conducting sled tests using anthropomorphic test devices (ATDs). A secondary objective of this test series was to examine the influence of occupant body size (5th percentile female, 50th percentile male, and 95th percentile male), military gear (helmet/vest/tactical assault panels), seat belt type (3-point and 5-point), and advanced seat belt technologies (pretensioner and load limiter) on occupant kinematics and injury risk in frontal crashes.

Methods: In total, 20 frontal sled tests were conducted using a custom sled buck that was reconfigurable to represent both the driver and passenger compartments of a light tactical military vehicle. Tests were performed at a delta-V of 30 mph and a peak acceleration of 25 g. The sled tests used the Hybrid III 5th percentile female, 50th percentile male, and 95th percentile male ATDs outfitted with standard combat boots and advanced combat helmets. In some tests, the ATDs were outfitted with additional military gear, which included an improved outer tactical vest (IOTV), IOTV and squad automatic weapon (SAW) gunner with a tactical assault panel (TAP), or IOTV and rifleman with TAP. ATD kinematics and injury outcomes were determined for each test.

Results: Maximum excursions were generally greater in the 95th percentile male compared to the 50th percentile male ATD and in ATDs wearing TAP compared to ATDs without TAP. Pretensioners and load limiters were effective in decreasing excursions and injury measures, even when the ATD was outfitted in military gear.

Conclusions: ATD injury response and kinematics are influenced by the size of the ATD, military gear, and restraint system. This study has provided important data for validating FE models of military occupants, which can be used for design optimization of military vehicle restraint systems.     

I don't feel that about environmental psychology today. But I want to

Environmental psychology—psychogeography as many geographers called it-was a politically motivated attempt on the part of academicians of the late 1960s to transform their study into a form of praxis, with consequences for the choice of subjects (more naturally occurring) and methods (more ethological). In geography, theoretical foundations were perceived in the work, among others, of Carl Sauer and J. K. Wright, while William Bunge exemplified the possibilities of geography as praxis. The joint venture was exciting, not because it was new, but because it was perceived as having consequences in the world of action. This shaped the work more than anything. Contemporary work lacks these qualities. In a phrase, it doesn't matter. It needs to.     

The European Directive on environmental impact assessment: Implementation at last?

Summary The Commission of the European Communities' directive on environmental impact assessment (EIA) finally came into force in July 1988. The main provisions of the Directive are described, together with the objectives it is intended to achieve and the key areas where member state legislation will need to be effective if the principal requirements of the Directive are to be properly implemented. These include adequate coverage of projects, sufficient information in EIA studies, and effective consultation and public participation. Most European countries have some experience with EIA but, as illustrated by the UK Channel Fixed Link reports, the quality of the studies undertaken is very variable. Recommendations are made for improvements in practice through more effective diffusion of best practice, better provision and use of EIA guidance, more focused EIA research, more effective consultation and closer collaboration between the different parties involved in the EIA process, and both quantitative and qualitative improvements in EIA training. The results of a recent survey of European EIA training activity indicate growing interest, but further progress in improving the provision of EIA training is needed before the Directive can be effectively implemented.Drs Christopher Wood and Norman Lee have both been involved on various Environmental Impact Assessment (EIA) studies for the European Commission and have written widely on EIA and related topics. Both are Senior Lecturers at the University of Manchester and they are co-Directors of its EIA Centre. Christopher Wood teaches mainly in the Department of Town and County Planning, Norman Lee in the Department of Economics.     

Controlling residential water demand in Qatar: an assessment

Qatar has serious water resource problems, following rapid socioeconomic development and massive population increase. Municipal water provision depends on costly and unsustainable desalination. There is little regulation. Native Qataris do not pay a water tariff and migrants pay a subsidized price--approximately one third of the cost of production--so there is little awareness of the true cost of water and use is profligate. This paper discusses trends in water use and identifies issues underlying sustainable water use in Qatar. A questionnaire of respondents chosen to represent Qatari social groups measured awareness and attitudes to water. The results show that previous efforts to control water demand in Qatar, using awareness campaigns, legal restrictions and tariffs, have been ineffectual. The questionnaire evaluated reactions to possible measures to limit uses by raising awareness, using legal restrictions and raising tariffs. From this, a number of policy changes can be suggested, to bring Qatar's water industry towards sustainability.     

Design of aquifer remediation systems: (2) estimating site-specific performance and benefits of partial source removal

A Lagrangian stochastic model is proposed as a tool that can be utilized in forecasting remedial performance and estimating the benefits (in terms of flux and mass reduction) derived from a source zone remedial effort. The stochastic functional relationships that describe the hydraulic "structure" and non-aqueous phase liquid (NAPL) "architecture" have been described in a companion paper (Enfield, C.G., Wood, A.L., Espinoza, F.P., Brooks, M.C., Annable, M., Rao, P.S.C., this issue. Design of aquifer remediation systems: (1) describing hydraulic structure and NAPL architecture using tracers. J. Contam. Hydrol.). The previously defined functions were used along with the properties of the remedial fluids to describe remedial performance. There are two objectives for this paper. First, is to show that a simple analytic element model can be used to give a reasonable estimate of system performance. This is accomplished by comparing forecast performance to observed performance. The second objective is to display the model output in terms of change in mass flux and mass removal as a function of pore volumes of remedial fluid injected. The modelling results suggest that short term benefits are obtained and related to mass reduction at the sites where the model was tested.     

Sizing of atmospheric particulates with a high volume cascade impactor

This article describes the development of a high volume cascade impactor with a sampling rate of 20 ft³/min that can be powered by high volume blowers in common use for air sampling. With this impactor it is now possible to collect enough sample of atmospheric particulates in a 24 hour period to conveniently determine an aerodynamic size distribution of suspended particulates by gravimetric analysis. The impactor has four stages and an after-filter and separates particles from the air stream by inertial impaction. The effective cutoff diameters for the stages are 7.0, 3.3, 2.0, and 1.1 microns. The after-filter traps the submicron material.     

Growth of the kelp Ecklonia radiata near the northern limit of its range in Western Australia

The length, growth and survivorship of mature sporophytes of Ecklonia radiata (C.Ag.) J. Agardh were measured on two patch reefs within the lagoon of a high-latitude, coralreef atoll (Easter Group, Houtman Abrolhos; 28° to 29° S; 113°35 to 114°03E) for 1 yr (1982–1983). The sites differed in their proximity to the perimeter reef, but had similar regimes of temperature, light, nutrient concentration and water movement. Kelp length, growth rate and survivorship differed significantly between sites, although plant density was similar (less than l m^-2). At the site near the lagoon perimeter, the central lamina averaged 381 mm in length, grew at an annual mean rate of 1.28 mm d^-1, and 56% of tagged individuals had died after one year. The corresponding values for the site near the centre of the lagoon were: 257 mm, 0.75 mm d^-1 and 92%. Three other sites on the coastal limestone reefs near Perth (400 km to the south) were studied for various intervals over a 5 yr period (April 1979 to August 1984). The kelp from the low-latitude sites were smaller, grew more slowly, and suffered similar or greater mortality than their southern counterparts. Latitudinal comparisons were confounded by differences in kelp density between sites, but there is no evidence for density-dependent effects on the measured parameters across the range of natural densities observed. Growth rates at all sites were negatively correlated with ambient sea temperatures when these were above 20°C. There was no evidence of adaptation to the higher sea temperatures experienced at the Abrolhos, and temperature cannot be dismissed as a factor controlling the growth of the species near the northern limit of its distribution on the Western Australian coast. Other factors however must be involved in determining the latitudinal position of that limit.     

Wetland cultivation and hydrological management in eastern Africa: Matching community and hydrological needs through sustainable wetland use

Wetlands are critical natural resources in developing countries where they perform a range of environmental functions and provide numerous socio-economic benefits to local communities and a wider population. In recent years, however, many wetlands throughout eastern Africa have come under extreme pressure as government policies, socio-economic change and population pressure have stimulated a need for more agriculturally productive land. Although wetland drainage and cultivation can make a key contribution to food and livelihood security in the short term, in the long term there are concerns over the sustainability of this utilization and the maintenance of wetland benefits. This article draws upon recent research carried out in western Ethiopia, which addressed the sustainability of wetland agriculture in an area of increasing food insecurity and population pressure. It discusses the impacts of drainage and cultivation on wetland hydrology and draws attention to local wetland management strategies, particularly those characterized by multiple use of wetlands, where agriculture exists alongside other wetland uses. The article suggests that where multiple wetland uses exist, a range of benefits can be sustained with little evidence of environmental degradation. Ways of promoting and empowering such sustainable wetland management systems are discussed in the context of the wider need for water security throughout the region.