Design and implementation of ergonomic risk assessment feedback system for improved work posture assessment

Ergonomic risk factors which include force, repetition and awkward postures, can result in Work-Related Musculoskeletal Disorders (WMSDs) among workers. Hence, systems that provide real-time feedback to the worker concerning his current ergonomic behaviours are desirable. This paper presents the design and implementation of a human-machine interface posture assessment feedback system whose conceptual model is developed through a model-driven development perspective using the Unified Modeling Language (UML) and interface flow diagrams. The resulting system provides a shop floor with a simple, cost-effective and automatic tool for real-time display of worker's postures. Testing the system on volunteer participants reveals that it is easy to use, achieves real-time posture assessment and provides easy-to-understand feedback to workers. This system may be useful for reducing the rate of occurrence of awkward postures, one of the contributing factors to risk of WMSDs among workers.     

Effects of sintering temperature on morphology and mechanical characteristics of 3D printed porous titanium used as dental implant

Porous titanium samples were manufactured using the 3D printing and sintering method in order to determine the effects of final sintering temperature on morphology and mechanical properties. Cylindrical samples were printed and split into groups according to a final sintering temperature (FST). Irregular geometry samples were also printed and split into groups according to their FST. The cylindrical samples were used to determine part shrinkage, in compressive tests to provide stress-strain data, in microCT scans to provide internal morphology data and for optical microscopy to determine surface morphology. All of the samples were used in microhardness testing to establish the hardness. Below 1100 °C FST, shrinkage was in the region of 20% but increased to approximately 30% by a FST of 1300 °C. Porosity varied from a maximum of approximately 65% at the surface to the region of 30% internally. Between 97 and 99% of the internal porosity is interconnected. Average pore size varied between 24 μm at the surface and 19 μm internally. Sample hardness increased to in excess of 300 HV0.05 with increasing FST while samples with an FST of below 1250 °C produced an elastic–brittle stress/strain curve and samples above this displayed elastic–plastic behaviour. Yield strength increased significantly through the range of sintering temperatures while the Young's modulus remained fairly consistent.     

Potassium supplementation induces beneficial cardiovascular changes during rest and stress in salt sensitive individuals.

The typical American diet includes high salt and low potassium, a pattern linked to elevated blood pressure (BP) in cross-cultural studies. This study compared resting and stress cardiovascular responses on a high salt, low potassium diet to those observed during 2 interventions: salt restriction and potassium supplementation. Forty-seven percent of the primarily normotensive sample (n?=?67 adults) were salt sensitive, showing a decrease in mean arterial pressure ≥5 mmHg during low salt and equivalent reductions during high potassium. The equivalent benefits of the interventions were maintained, but not enhanced, during exposure to behavioral stress (i.e., no effect on reactivity). Salt resistants (SRs) exhibited no change in resting or stress BP across the diets. High salt increased cardiac index in both groups, whereas vascular tone was decreased only in the SR group. High potassium produced hemodynamic benefits similar to low salt, even with continued high salt intake. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age effects on executive ability.

Heterogeneity of executive tasks has made it difficult to determine whether there are age-related declines in executive functioning. To address this issue, 112 individuals, 20–79 years old, took the California Trail Making Test (CTMT) and the California Stroop Test (CST), subtests of the Delis–Kaplan Executive Function Scale (D. C. Delis, E. Kaplan, & J. H. Kramer, in press) that include measurement of component skills embedded in the executive function tasks. Multiple regression analyses revealed that after controlling for component skills, age had a significant effect on the executive requirement of the CST, namely speed on the interference condition. Age did not affect switching performance on the letter–number condition of the CTMT. Additional analyses revealed that age was significantly associated with commission of certain types of errors. This study confirms the importance of partialing out components in the assessment of multidimensional cognitive tasks, particularly when making age comparisons. It also emphasizes specificity over generalizability when examining the impact of age on cognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Colorimetric quantification of amino groups in linear and dendritic structures

BACKGROUND: The aim of the work reported was to develop a procedure using 96‐well microtiter plates for the easy determination of protonated groups of compounds including linear poly(amino acid)s and dendritic polymers divided into dendrigraft and dendrimeric structures. This study is a prerequisite step for the quantification of protonated groups in a macromolecule grafted onto a solid surface. RESULTS: The procedure was developed from the modified Bradford protein assay and incorporates several modifications that enable one to determine available amino groups (or even other cationic groups) present on the polyresidues backbone, all within five minutes. Based on the Atherton mathematical model, we evaluated the maximal number of Coomassie blue binding sites on linear, dendrigraft or even dendrimeric structures. CONCLUSION: The mean calculated percentage of occupied sites on a given macromolecule led us to demonstrate that one Coomassie blue molecule interacts with only one single protonated group. Consequently, the developed method using Coomassie blue binding can be used for the quantification of cationic groups in a macromolecule grafted onto a solid surface. Copyright © 2009 Society of Chemical Industry     

Structure formation in solutions of isotactic poly(methacrylic acid) in dimethyl formamide

Summary Structure formation in solutions of non-neutralised isotactic poly(methacrylic acid) in dimethyl formamide was studied. Fourier transformed infrared spectroscopic measurements, X-ray diffraction analysis and dynamic rheological observations revealed that two different processes of structure formation can take place. The first process can lead to the formation of very weak, thermoreversible gels. It is proposed to consist of an intramolecular coil-to-helix transition, followed by an intermolecular association. The second one shows the characteristics of a crystallisation into a supramolecular organisation different from what is obtained in the first process. These processes can compete with each other and this depends on the experimental conditions, the molar mass and the tacticity of the sample.     

University counseling center consultation: Developing a faculty outreach program.

A faculty outreach program created by a university counseling center had the goals of strengthening the working relationship between staff of the center and academic faculty, informing faculty of the center's services and their relationship to the academic mission, providing coordination of academic departments' requests for outreach and consultation services, and increasing center staff involvement in outreach services to faculty. In its first year this program reached 53 departments and programs and 370 faculty and staff. The program design, results, and future directions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tensile strength of glass fibres with carbon nanotube–epoxy nanocomposite coating: Effects of CNT morphology and dispersion state

The effects of carbon nanotube (CNT)–epoxy nanocomposite coating applied to glass fibre surface on tensile strength of single glass fibres are evaluated at different gauge lengths. The crack healing efficiencies obtained using two different types of CNTs with different structures, morphologies and dispersion characteristics in various concentrations are specifically studied. The results indicate that the tensile strength of single fibres increased significantly with increasing CNT content up to a certain level, depending on the type of CNTs. The crack healing efficiency was much higher for the fibres coated with straight, less entangled CNTs than those with highly entangled CNTs, indicating the CNT dispersion state in the coating played an important role. A strong correlation is established between the CNT dispersion state, the tensile properties of nanocomposite and the tensile strengths of fibres with the nanocomposite coating.     

Optical properties of randomly distributed soot: improved polarimetric and intensity scattering functions

Reference scattering curves for polarization and intensity produced by aggregates and agglomerates of ethylene and kerosene soot are obtained for scattering angles in the 10-170 degrees range. The polarization measurements were obtained with the Propriétés Optiques des Grains Astronomiques et Atmosphériques instrument for particles that levitate in microgravity during parabolic flights and on the ground by an air draught technique. The intensity measurements were obtained also on the ground with a Laboratoire de Metéorologie Physique nephelometer. The maximum polarization is of the order of 80% at a scattering angle of 80 degrees at lambda = 632.8 nm and approximately 75% at an angle of 90 degrees at lambda = 543.5 nm. The polarization increases by approximately 10% when the size of the agglomerate increases from 10 microm to a few hundred micrometers. The intensity curve exhibits a strong increase at small scattering angles. These reference curves will be used in the near future for the detection of stratospheric soot by remote-sensing measurement techniques.     

Herstellung und Anwendungsmöglichkeiten von Eiweiß-Fettsäurekondensaten

Production and application of acylated protein hydrolysates Acylated protein hydrolysates are very mild surfactants based on protein as a renewable natural resource. Protein raw materials of animal or plant sources are hydrolyzed and acylated with fatty acid chlorides according to Schotten-Baumann. Compared to surfactants based on fats or carbohydrates, acylated protein hydrolysates are different in application due to their hydrophilic protein part. In the formulation of surfactants, addition of small amounts of acylated protein hydrolysates to the more strongly irritating bulk surfactants results in a more than proportional improvement in their compatibility with the skin.