Elbow flexion strength curves in untrained men and women and male bodybuilders

The mechanical response of intervertebral joints is deeply influenced by disc degeneration. The phenomenon is expressed in terms of variations in the biomechanical properties of the material, whose compressibility characteristics change because of the liquid content loss in the tissue and, what is even more important, to prolapse. In this work, the problem is investigated by means of a computational mechanics approach; a coupled material and geometric non-linear model is developed, representing vertebra, annulus and nucleus submitted to an axial load. A transversely isotropic law is assumed for cortical bone in the vertebral body and an isotropic law for the cancellous portion; a hyperelastic formulation is assumed for the disc, allowing effective interpretation of the mechanical characteristics of degeneration. The results obtained are reported with regard to bony endplate and annulus behaviour; interaction phenomena between bony endplate and nucleus are emphasized.     

The role of the WO x ad-component to Pt and PtRu catalysts in the electrochemical CH3OH oxidation reaction

High surface area carbon-supported platinum-based catalysts, Pt/C, PtWO _x /C, PtRu/C and PtRuWO _x /C, were prepared via a chemical reduction route using single metal precursor salts. The catalyst particles were found to be in the nanoscale range, and the addition of Ru clearly decreased the particle size. The Ru was found to be partially incorporated into the face centered cubic lattice of Pt and to form a single Ru catalyst component. X-ray diffraction and X-ray photon spectroscopy did not provide evidence for electronic interactions between WO _x and Pt as well as WO _x and Ru. However, the addition of tungsten to the PtRuWO _x /C catalyst resulted in a high degree of catalyst particle agglomeration. Both Ru containing catalysts showed significantly higher activities for the CH₃OH oxidation reaction in terms of Pt + Ru mass as well as electroactive Pt + Ru surface area than the Pt/C and PtWO _x /C catalysts. The addition of tungsten appeared to mainly result in some ‘physical’ modification of the catalytically active Pt and Ru surface components such as differences in electroactive surface area rather than promotion of the CH₃OH oxidation reaction via a true catalytic mechanism.     

The electrochemical reduction of VO2 in acidic solution at high overpotentials

An investigation has been carried out to attempt to understand the unusually low apparent symmetry factor observed during the reduction of V(5) at higher overpotentials at carbon electrodes (typically <0.13, or >460 mV decade⁻¹). This reaction is of interest because it occurs in vanadium redox-flow batteries (VRBs) during discharge. Polarisation curves were measured using a rotating disk electrode (RDE). The reaction was not solution mass transport controlled, was pH independent (ca from 0 to 1), and the observed Tafel slope was unaffected by V(5) concentration over a range from 0.031 to 280 mM. Electrode double layer capacitance measurements were also carried out in sulphuric acid with and without vanadium. These tests showed that the presence of V(5) caused a suppression of the normal carbon surface quinone pseudocapacitance, as well as the appearance of two new pseudocapacitance peaks, one around 0.175-0.2 V and the other around 0.675-0.725 V versus SCE. The observed results do not appear consistent with a precipitated film causing diffusion limitations or causing IR drop. A model is developed to try to explain the data, which involves electron transfer through an adsorbed layer of vanadium.     

Estimation of the costs of acute gastrointestinal illness in British Columbia, Canada

The costs associated with gastrointestinal infection (GI) in the province of British Columbia, Canada, were estimated using data from a population-based survey in three health service delivery areas, namely Vancouver, East Kootenay and Northern Interior. The number of cases of disease, consequent expenditure of resources and associated economic costs were modeled as probability distributions in a stochastic model. Using 2004 prices, the estimated mean annual cost per capita of gastrointestinal infection was CAN$128.61 (euro207.96), with a mean annual cost per case of CAN$1,342.57 (euro2,170.99). The mean estimate of the overall economic burden to British Columbia was CAN$514.2 million (euro831.5 million) (95% CFI CAN$161.0 million to CAN$5.8 billion; euro260.3 million to euro9.38 billion). The major element of this cost was the loss of productivity associated with time away from paid employment by both the sick and their caregivers. Sensitivity analysis suggested that the uncertainty associated with the base model assumptions did not significantly affect the estimates. The results are comparable to those obtained in an earlier study using a similar analytical framework and data from the city of Hamilton, Ontario, Canada.     

Comparison of optical and physical measurements with sensory assessment of the ripeness of tomato fruit Lycopersicon esculentum

Knowledge of the inter-relationships among objective physical and optical measurements and their relation with sensory perception of foods can be applied to improve quality control and consumer acceptance. Changes in the optical and mechanical properties of tomatoes were found to be related to the perceived ripeness of the fruit over a storage period. The sensory attributes and instrumental parameters significant in the assessment of ripening tomatoes were translucency, green, orange, lightness, hue and chroma. The chromatic co-ordinate a^* was significantly correlated with the mechanical modulus of the fruit, which in turn was inversely related to ripening associated with colour changes from green to red. It is feasible that mechanical and optical data may be combined to provide an on-line system for the evaluation of ripeness of tomato fruit.     

The effects of long‐term exposure of flax fiber reinforced polymer to salt solution at high temperature on tensile properties

Most research on natural fiber composites has been primarily conducted on randomly‐oriented fibers. This study is focused on the short‐ and long‐term performances of flax fiber‐reinforced polymer (Flax‐FRP) made from continuous unidirectional fiber mats, and compares it to Glass‐FRP composite. The study looked into the effect of number of layers on properties, comparing wet layup (WL) to vacuum bag (VB) molding, and aging in a 3.5% salt solution for up to 365 days at 23, 40, and 55°C. Results show that Flax‐FRP has a tensile strength and modulus of one third the values of Glass‐FRP. Using the VB process, Flax‐FRP showed a strength and modulus 18 and 36% higher, respectively, than WL specimens. As the number of layers increased from one to five, the strength and modulus also increased but stabilized at three layers. After 365 days of conditioning at 23, 40, and 55°C, WL specimens showed a strength retention of 81, 73, and 69%, respectively. Using the Arrhenius relationship, it was estimated that both WL and VB Flax‐FRP would retain 60% of their tensile strength after 100 years of saltwater exposure at an annual mean temperature of 10°C. POLYM. COMPOS., 37:3234–3244, 2016. © 2015 Society of Plastics Engineers     

Solid-state nuclear magnetic resonance investigation of cation siting in LiNaLSX zeolites

The location of Li⁺ and Na⁺ cations in a series of dehydrated low-silica LiNaX zeolites (LiNaLSX, framework Si/Al ratio=1.0) were characterized by ⁷Li and ²³Na magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. Depending on the Li⁺ content, up to three lines were observed in the ⁷Li MAS NMR spectra attributed to Li⁺ cations on SI′, SII and SIII sites. The ²³Na MAS NMR spectra of the pure sodium form NaLSX and of LiNaLSX samples with low Li⁺ contents contain up to five lines belong to Na⁺ cations located on SI, SI′, SII, and two different SIII′ sites. LiNaLSX zeolites containing more than 40% of Li⁺ show only a single narrow line in the ²³Na MAS NMR spectra attributed to mobile sodium cations. The populations of the different cation sites were determined from the relative line intensities of the MAS NMR spectra. Below about 70% Li⁺ exchange, lithium cations are located only on sites SI′ and SII. Between 70% and 100% Li⁺ content these sites are fully occupied by Li⁺, and the population of site SIII by Li⁺ increases. It was found that the nitrogen-adsorption capacity correlates well with the occupation of Li⁺ at site SIII.     

Synthesis of Solid Phosphate Compounds of Ti(III) and Ti(IV)

Several new methods for the synthesis of TiPO₄ are described. Crystalline phosphate compounds containing boron and titanium in a single III or mixed (III, IV) oxidation states have been synthesized and identified by X-ray diffraction. An additional family of phosphate compounds containing only Ti(III, IV) has also been synthesized and identified. All the compounds exhibit attractive colors, e.g., bright green, blue, purple, and black, and are stable at room temperature in air and in boiling water.     

The education of the deaf in Canada.

Some problems in the field of Deaf Education are described. It is maintained that the dominant system of educating the deaf in North America, usually referred to as the oralist approach, has been a failure. Reasons for the failure of pure oralism are offered, and some suggestions are made for an approach to Deaf Education which would involve the introduction of the language signs and fingerspelling at the time critical for language development. Also, the relationship of the adult deaf community to the educational system is discussed, and suggestions are made concerning the potential of Instructional Television for adult deaf education as well as for the education of deaf children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Subjective visual vertical in virtual reality (Curator SVV): validation and normative data

Subjective visual vertical (SVV) assesses the ability to perceive verticality, which is a measure of vestibular otolithic function. Vestibular lesions influence this perception of verticality. We developed a method using virtual reality (VR) display and an Android software application named ‘Curator SVV’. The virtual reality SVV (Curator SVV) consisted of ten readily identifiable artworks projected by a Samsung phone S6 which is inserted into a virtual reality headset. In the first study, 20 patients had there SVV assessed with two devices: (1) a commercially available SVV measurement device (VestiTest^®) and (2) a virtual reality SVV using the Curator SVV application. In a second study, 32 healthy subjects had their SVV assessed by the Curator SVV application whilst sitting in a chair. In the first study, there was no significant difference (p = 0.44, paired t test and p = 0.01, test of equivalence) between results obtained by Curator SVV and the commercially available device. In the second study, the average angle measured for healthy subjects was 0.00° ± 0.85°. The normal range (mean ± 2 SD) was ± 2° in standard upright position. We were able to demonstrate that the Curator SVV can be readily employed as an objective, non-invasive and affordable means of assessing otolith function in the clinical context. We validated this novel methodology by finding strong quantitative parity between a standard commercial SVV unit and the VR Curator SVV method. Our very lightweight and mobile device can be employed in clinical contexts including at the bedside and in different head and body positions.