Two posture analysis approaches and their application in a modified rapid upper limb assessment evaluation

This paper presents two posture risk quantification methods: first, an event-based method where the most common and the worst postures are estimated in a task; second, a time-based method where posture distributions are calculated from random samples of observed postures in the task. A 'click-on-screen' posture data entry method was developed for the time-based posture analysis method to make the observation process easier and to reduce possible posture categorization bias. Both methods were used to quantify various work posture parameters among a study cohort of 733 subjects from a prospective epidemiological study of upper extremity musculoskeletal disorders. Composite posture indices using a modified Rapid Upper Limb Assessment (RULA) method were also computed using data obtained by the two posture analysis methods. Results showed that both methods were able to distinguish jobs with large differences in certain posture measures. However, they did not produce the same results and could not be used interchangeably. Risk evaluation criteria should be developed, either for specific posture parameters or as a composite index, with a well-defined postural analysis method, so that users can follow exact procedures and obtain comparable results. The event-based method is easy to use and may suit practitioners better, while the time-based method adds more information to the measurement and may suit users who want more detailed information about posture exposure.     

Coercivity Control of Variable-Length Iron Chains in Phthalocyanine Thin Films

The magnetic characteristics of iron phthalocyanine thin films are studied with a vibrating sample magnetometer, identifying a ferromagnetic transition temperature at 4.5?K. The metal ions at the center of the molecule are self-assembled along chains producing quasi one-dimensional magnetic chains of variable length in the thin films. The average chain length is varied from 20 to 300?nm via substrate temperature during deposition. Below the critical transition temperature, the magnetization curves have the shape of wasp-waisted or constricted loops. The in-plane chain length modulates the coercivity and saturation field and larger grains increase the coercivity significantly. First-order reversal curves of the wasp-waisted hysteresis loops reveal a long narrow strip that suggests a broad distribution of coercive fields and weak intergrain magnetic interactions. These findings are also supported through simulations based on the Preisach model.     

Driving behaviors in early stage dementia: A study using in-vehicle technology

According to the Alzheimer's Association (2011), (1) in 8 people age 65 and older, and about one-half of people age 85 and older, have Alzheimer's disease in the United States (US). There is evidence that drivers with Alzheimer's disease and related dementias are at an increased risk for unsafe driving. Recent advances in sensor, computer, and telecommunication technologies provide a method for automatically collecting detailed, objective information about the driving performance of drivers, including those with early stage dementia. The objective of this project was to use in-vehicle technology to describe a set of driving behaviors that may be common in individuals with early stage dementia (i.e., a diagnosis of memory loss) and compare these behaviors to a group of drivers without cognitive impairment. Seventeen drivers with a diagnosis of early stage dementia, who had completed a comprehensive driving assessment and were cleared to drive, participated in the study. Participants had their vehicles instrumented with a suite of sensors and a data acquisition system, and drove 1–2 months as they would under normal circumstances. Data from the in-vehicle instrumentation were reduced and analyzed, using a set of algorithms/heuristics developed by the research team. Data from the early stage dementia group were compared to similar data from an existing dataset of 26 older drivers without dementia. The early stage dementia group was found to have significantly restricted driving space relative to the comparison group. At the same time, the early stage dementia group (which had been previously cleared by an occupational therapist as safe to drive) drove as safely as the comparison group. Few safety-related behavioral errors were found for either group. Wayfinding problems were rare among both groups, but the early stage dementia group was significantly more likely to get lost.     

Soot oxidation kinetics under pressurized conditions

The oxidation kinetics, under different pressures, of soot samples obtained from different liquid fuels and two standards (a commercial black carbon sample and a reference diesel soot) was studied. Soot samples were generated in a flat-flame, premixed burner under heavily-sooting conditions and captured on a water-cooled stabilization plate located above the burner surface. The collected soot was oxidized using a high-pressure thermogravimetric analyzer (HTGA). TGA operation was optimized to reduce mass transfer effects by adjusting the oxidizer flow rate and initial sample mass. Further corrections for mass transfer were accomplished by computing the effectiveness factors for intraparticle, interparticle, and external mass transfer. Two pressures were evaluated (1 and 10 atm) and O₂ concentration was varied between 10 and 21%.     

High porosity,responsive hydrogel copolymers from emulsion templating

Hydrogels, three‐dimensional hydrophilic polymer network structures, can absorb many times their dry weight in water. PolyHIPEs are highly porous polymers synthesized within high internal phase emulsions (HIPEs). Here, the water uptakes in novel hydrogel polyHIPE copolymers of hydroxyethyl methacrylate (HEMA, a non‐ionic monomer) and methacrylic acid (MAA, an ionic monomer) were investigated. The PHEMA‐based polyHIPE had a density of 0.14 g cm^?3, void diameters of 50–100 µm and a void‐dominated Fickian water uptake of around 10.4 g g^?1. The polyHIPE density increased, and the porous structure became less polyHIPE‐like, with increasing MAA content, reflecting a reduction in the stability of the HIPE. The water uptake increased with increasing pH for all the copolymers and the water absorption mechanism changed from Fickian at pH 2 to anomalous, dominantly case II, at pH 10. The maximum uptake of 18.2 g g^?1 at pH 10, for a HEMA to MAA mass ratio of 1/1, was ascribed to hydrogel‐swelling‐driven void expansion. The hydrogel's absorptive and responsive properties were amplified by the polyHIPE's porous structure. These results demonstrate that the compositions of hydrogel polyHIPE copolymers can be designed to enhance their water uptake. © 2015 Society of Chemical Industry     

Hexafluoropropylene plasmas: Polymerization rate–reaction parameter relationships

Plasma polymerization generates thin, pinhole-free, and highly adhering films and is often described by the ratio of power to mass flow rate (energy per mass). This research explores the relationships between plasma reactor parameters such as monomer flow rate, plasma power, and reactor pressure and the rates of polymerization, etching, and deposition. The chemical structure of the amorphous, crosslinked plasma polymerized hexafluoropropylene consists largely of similar amounts of C*-CF, CF, CF₂, and CF₃ groups and some C-C groups. A dimensionless plasma parameter (E) proportional to power and inversely proportional to flow rate cubed was derived. E, reflecting both plasma energy and residence time, was used to describe various aspects of the plasma reactions. A dimensionless exponential expression successfully described the dependence of pressure on E with a master curve. An expression for polymerization efficiency (polymer conversion) derived in part through a mass balance was also successfully related to E using an exponential master curve. The rate of deposition was described as the difference between the rates of polymerization and etching. The deposition efficiency maximum and plateau were successfully described by the difference between polymerization and etching efficiencies, each related exponentially to E. The technique used to derive parameters to describe the dependence of plasma reactions on plasma operating conditions can be applied to any monomer/reactor system.     

Listening to parents' voices: Participatory action research in the schools.

How can schools and parents work together more effectively? This article describes a participatory action research (PAR) project with a group of parents whose children had been classified as having emotional disabilities. As the parents shared their stories of trying to navigate the special education system, they developed critical consciousness about their experiences of stress, powerlessness, and alienation. They became mobilized and obtained information about testing, diagnostic classification, and educational options for their children. Armed with this information, they developed and implemented an action plan to improve family-school relationships at the local, community, and state levels. The article concludes with an example of how the PAR model can be exported to a variety of mental health settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)