Two distinct mechanisms upon absorption of volatile organic compounds into siloxane polymers.

The response of polysiloxane materials to volatile organic compounds (VOCs) including benzene, toluene, ethylbenzene, and toluene (BTEX), as well as cyclohexane, acetone, methanol and isopropanol is studied using thin film large-angle refractometry. Refractive index and thickness changes are measured to quantify the diffusion rate and partition coefficients associated with the absorption and desorption of VOC vapours into polydimethylsiloxane (PDMS) and polydiphenylsiloxane (PDPS) - PDMS copolymer films. Absorption of volatile solvent vapours into siloxane polymers is found to follow two distinct mechanisms with different absorption rates. These mechanisms are also associated with different excess volumes of mixing and may be accompanied by a polymer restructuring step.

Refractive indices of common solvents and solutions at 1550 nm.

Using a large-angle refractometer, the refractive indices of water, methanol, acetonitrile, acetone, ethanol, formaldehyde solution, 2-propanol, hexanes, 1-propanol, 2-butanol, tetrahydrofuran, dichloromethane, 1,4-dioxane, cyclohexane, N,N-dimethylformamide, ethylene glycol, N,N-dimethylacetamide, chloroform, glycerol, trichloroethylene, dimethylsulfoxide, p-xylene, ethylbenzene, toluene, m-xylene, benzene, and o-xylene were measured at 1550 nm and compared to literature values. In addition, the refractive indices of 48 aqueous sucrose solutions, 34 aqueous sodium chloride solutions, 40 DMSO-water, 40 ethylene glycol-water, and 40 glycerol-water mixtures were also measured at different concentrations and fit with third-order polynomial expressions. This study provides near-infrared refractive indices that were not previously available and may help with the calibration of refractive index sensors that operate at or near 1550 nm.

Quantitative diffusion and swelling kinetic measurements using large-angle interferometric refractometry.

The uptake and release of sorbates into films and coatings is typically accompanied by changes of the films' refractive index and thickness. We provide a comprehensive model to calculate the concentration of the sorbate from the average refractive index and the film thickness, and validate the model experimentally. The mass fraction of the analyte partitioned into a film is described quantitatively by the Lorentz-Lorenz equation and the Clausius-Mosotti equation. To validate the model, the uptake kinetics of water and other solvents into SU-8 films (d = 40-45 µm) were explored. Large-angle interferometric refractometry measurements can be used to characterize films that are between 15 µm to 150 µm thick and, Fourier analysis, is used to determine independently the thickness, the average refractive index and the refractive index at the film-substrate interface at one-second time intervals. From these values the mass fraction of water in SU-8 was calculated. The kinetics were best described by two independent uptake processes having different rates. Each process followed one-dimensional Fickian diffusion kinetics with diffusion coefficients for water into SU-8 photoresist film of 5.67 × 10(-9) cm(2) s(-1) and 61.2 × 10(-9) cm(2) s(-1).

Quantification of different water species in acetone using a NIR-triple-wavelength fiber laser.

A fiber laser using a thulium-doped ZBLAN gain medium was used to generate laser radiation simultaneously at 1461, 1505 and 1874 nm, with > 5 mW output power at each of the wavelengths. The laser was used to quantify the near-infrared absorption of liquid water in acetone. Additionally, near-infrared spectra were recorded using a broad band source and were interpreted using parallel factor (PARAFAC) analysis to rationalize the concentration-dependent peak shifts.

Reviewing current knowledge in snatch performance and technique: the need for future directions in applied research.

This is a review of current research trends in weightlifting literature relating to the understanding of technique and its role in successful snatch performance. Reference to the world records in the snatch from the 1960s onwards indicates little progress across all weight categories. With such mediocre advances in performance at the International level, there is a need to better understand how snatch technique can improve performance even if only by a small margin. Methods of data acquisition for technical analysis of the snatch have involved mostly 2-dimensional barbell and joint kinematics. Although key variables which play a role in the successful outcome of a snatch lift have been heavily investigated, few studies have combined variables relating both the barbell and the weightlifter in their analyses. This suggests the need for a more detailed approach integrating both barbell-related and weightlifter-related data to enhance understanding of the mechanics of a successful lift. Currently, with the aid of technical advances in motion analysis, data acquisition, and methods of analysis, a more accurate representation of the movement can be provided. Better ways of understanding the key characteristics of technique in the snatch could provide the opportunity for more effective individualized feedback from the coach to the athlete, which should in turn lead to improved performance in competition.

Monitoring of vapor uptake by refractive index and thickness measurements in thin films.

We report a method for real-time monitoring of vapor uptake by simultaneous detection of the refractive index, n, and thickness, d, of thin transparent films with a precision of δn=10(-4) and δd<100 nm. The setup combines total internal reflection (Abbé) refractometry with an interferometric imaging method. A fast Fourier transform and phase fitting method is applied for accurate and independent determination of refractive indices and thicknesses. While the uptake of acetone vapor by polydimethylsiloxane is investigated, the system is also suited for characterization of other solid and liquid films.

Membrane bioreactor treatment of commonly used organophosphate pesticides.

Five pesticide formulations registered for use in Canada containing organophosphate-insecticide active ingredients azinphos-methyl, chlorpyrifos, diazinon, malathion and phorate were subjected to treatment by membrane bioreactor (MBR) technology. The target active ingredients were introduced to the MBR at ppm level concentrations. The biodegradation of these compounds was analyzed daily using selected ion monitoring gas chromatography-mass spectrometry (GC/MS-SIM) following extraction of the analytes using solid-phase extraction (SPE). Amounts measuring 83 % to 98 % of the target analytes were removed with steady-state concentrations being reached within 5 days of their introduction. The dissolved oxygen, temperature, pH, and total heterotrophic bacterial population were monitored daily to ensure optimal conditions for biodegradation. The quality of the effluent from the MBR was assessed daily through spectrophotometric methods. Measurements were conducted for the concentration of ammonia, nitrate, nitrite, total and reactive phosphorus, as well as the chemical oxygen demand (COD) of the effluent. This study demonstrated that the MBR technology is feasible and efficient for treatment of organophosphate pesticides without introducing additional chemical additives.

Mechanisms and classifications of Chronic Obstructive Pulmonary Disease: a literature review.

COPD is a prevalent chronic health condition secondary to only heart disease and stroke. A review of the literature reveals whilst smoking is the most common aetiological factor, environmental and occupational pollutions, genetic predisposition, hyper-responsive airways and respiratory infections are additional mechanisms to the development of COPD in susceptible individuals. Assessment of the severity of COPD via spirometry is considered the gold standard in quantifying the degree of respiratory impairment experienced by the client with the condition. However, there are inconsistent parameters of disease severity between each of the international respiratory bodies, which must influence reporting of outcomes. This paper reviews the literature reports of the mechanisms; systemic effects, disease-staging systems used in COPD and the relationship between disease severity and health outcomes.

The process of implementing a nurse-coordinated multidisciplinary pulmonary rehabilitation program in Melbourne.

In March 2002 The Northern Clinical Research Centre, Epping implemented a six week outpatient based pulmonary rehabilitation program for people with COPD. This paper outlines the establishment, underlying philosophy, marketing, coordination and personnel necessary for a successful program, as identified by the research centre. Barriers to program participation were identified and steps to minimize these were implemented. The longitudinal evaluation of this program in a prospective manner enables the duration of the effect of this adjunctive therapy to be examined in the Australian population. One hundred and thirty six participants have graduated from the research centre's pulmonary rehabilitation program since the program commenced in 2002. This paper reviews the process of implementing a pulmonary rehabilitation program in the northern corridor of Melbourne.