Variations in occupant response with seat belt slack and anchor location during moderate frontal impacts

Both seat belt slack and anchor location are known to affect occupant excursion during high-speed frontal collisions, but their effects have not been studied at moderate collision severities. The goal of this study was to quantify how seat belt slack and anchor location affect occupant kinematics and kinetics in moderate severity frontal collisions. A Hybrid III 50th percentile male dummy was seated on a programmable sled and exposed to frontal collisions with a speed change of 17.5 km/h. The seat belt was adjusted either snugly or with 10 cm slack (distributed 60/40 between the shoulder and lap portions) and the anchor location was varied by adjusting the seat position either fully forward or rearward (seat travel = 13 cm). Accelerations and displacements of the head, T1 and pelvis were measured in the sagittal plane. Upper neck loads and knee displacements were also measured. Five trials were performed for each of the four combinations of belt adjustment (snug, slack) and anchor location (seat forward, seat rearward). For each trial, kinematic and kinetic response peaks were determined and then compared across conditions using ANOVAs. Peak displacements, accelerations and loads varied significantly with both seat belt slack and anchor location. Seat belt slack affected more parameters and had a larger effect than anchor location on most peak response parameters. Head displacements increased a similar amount between the snug/slack belt conditions and the rearward/forward anchor locations. Overall, horizontal head displacements increased from 23.8 cm in the snug-belt, rearward-anchor configuration to 33.9 cm in the slack-belt, forward-anchor configuration. These results demonstrated that analyses of occupant displacements, accelerations and loads during moderate frontal impacts should consider potential sources of seat belt slack and account for differences in seat belt anchor locations.     

Speciation of Solutes in Drainage and Pore Waters of Two Former Lignite Mines (Germany)

An experimental speciation scheme consisting of ultra-filtration(1 kD), cation and anion exchange has been developed. Parallel calculations of the ion balances are performed using the computerroutine MINTEQA2. The experimental and computed ion balances suffer from non-equilibrium conditions, incalculability of metal-binding colloids or sub-colloids, inaccurate Eh measurements and analytical errors. In most samples colloidal or sub-colloidal structures of Fe oxy-hydroxides and/or gypsum influence the behavior of many trace elements. The comparison of theory and experiment has to be restricted to acid waters (pH < 5) where colloids (1–450 nm) and non-filterable colloids or sub-colloids (<1 nm) play a minor role. Yet, only a few transition metals such as Mn, Fe, Co, Ni, Cu, Zn, or Cd remain more or less free of colloidal influence in low pH waters. The effect of DOC on Al may be estimated by model substances like citrate.     

Divergence in sink contributions to population persistence

Population sinks present unique conservation challenges. The loss of individuals in sinks can compromise persistence; but conversely, sinks can improve viability by improving connectivity and facilitating the recolonization of vacant sources. To assess the contribution of sinks to regional population persistence of declining populations, we simulated source–sink dynamics for 3 very different endangered species: Black‐capped Vireos (Vireo atricapilla) at Fort Hood, Texas, Ord's kangaroo rats (Dipodomys ordii) in Alberta, and Northern Spotted Owls (Strix occidentalis caurina) in the northwestern United States. We used empirical data from these case studies to parameterize spatially explicit individual‐based models. We then used the models to quantify population abundance and persistence with and without long‐term sinks. The contributions of sink habitats varied widely. Sinks were detrimental, particularly when they functioned as strong sinks with few emigrants in declining populations (e.g., Alberta's Ord's kangaroo rat) and benign in robust populations (e.g., Black‐capped Vireos) when Brown‐headed Cowbird (Molothrus ater) parasitism was controlled. Sinks, including ecological traps, were also crucial in delaying declines when there were few sources (e.g., in Black‐capped Vireo populations with no Cowbird control). Sink contributions were also nuanced. For example, sinks that supported large, variable populations were subject to greater extinction risk (e.g., Northern Spotted Owls). In each of our case studies, new context‐dependent sinks emerged, underscoring the dynamic nature of sources and sinks and the need for frequent re‐assessment. Our results imply that management actions based on assumptions that sink habitats are generally harmful or helpful risk undermining conservation efforts for declining populations.     

Reducing the environmental impact of coal-washing practice in Australia

All Australian coal for export is washed — that is, the low-grade high-ash material is separated out and disposed of at the washery site. The coarse rejects are generally placed in embankments and the tailings are pumped into settling ponds. These methods of waste disposal can create environmental problems. In addition, they represent a significant energy loss, because about one-third of the waste material is combustible and is thus a potentially valuable source of energy. Laboratory studies at the CSIRO Division of Fossil Fuels at North Ryde, New South Wales, have shown that energy can be successfully recovered from washery wastes by the process of fluidized-bed combustion. A pilot fluidized-bed combustor, with a capacity of 2 tonnes/hour, is undergoing prolonged trial at the Clutha washery near Camden, New South Wales, in a joint project between the Joint Coal Board and CSIRO. The results from the pilot plant tests have provided the basis for a conceptual design and feasibility study for a full-scale tailings treatment plant. This study has indicated that fluidized-bed combustion:

1. offers an environmentally attractive and economically competitive alternative to the disposal of tailings in settling ponds, and
2. can be used to generate large quantities of energy from the wastes, reducing the energy lost in coal washing from around 16% to 6% of the coal mined.