Calf massager: Intervention for body muscle discomfort during prolonged standing

Many occupations require workers to stand for long periods of time without proper interventions, which causes discomfort in the back and lower limbs. Therefore, this study aims to assess the effectiveness in alleviating body muscle discomfort during prolonged standing through the use of a calf massager. This study was conducted among male workers at a manufacturer with production line workers and the list was obtained from the HR Department and simple random sampling was done by number categorization. A total of 100 respondents (50 respondents for both the control and the experimental groups) participated in this study. The experiment took place in a room with a similar setup for the production line. Each respondent was requested to perform the simulated task for 2 hr. For the experimental group, the calf massager was turned on every 15 min. At every 15‐min interval after turning on the calf massager, respondents from both groups were required to evaluate their discomfort level on a Borg's scale CR‐10 questionnaire. The results showed that the level of body discomfort among respondents in the experimental group reduced (20–30%) compared with that of the control group. Multivariate analysis results revealed that the discomfort rating for the lower back, knees, thighs, calves, and feet was significantly lower (p < .05) among the experimental group compared with the control group. For lower body parts, the lower back region was statistically significant (p < .05) at the 90th, 105th, and 120th min; the thigh region was statistically significant (p < .05) at the 120th min; the knee region was statistically significant (p < .05) at the 105th and 120th min; the calf region was statistically significant (p < .05) at all minute intervals except the 15th and 45th min, while the feet region, was statistically significant at the 105th and 120th min. Therefore, this study indicates that calf massage treatment is capable of reducing body muscle discomfort during prolonged standing and highlights the significance of calf massage.     

Fracture characteristics of a burst tested maraging steel rocket motor case

A 0.3 m diameter, 2 m long and 0.0015 m thick, 18 nickel 1800 MNm^–2 grade maraging steel motor case was designed, fabricated and burst tested to gain experience for using the steel as booster case material in satellite launch vehicles. The bursting occurred at 15.2 MPa for which the effective hoop stress worked out to be 1754 MNm^–2 almost equal to the ultimate tensile strength (1764 MNm^–2) of the material in the solution treated and aged condition. The failure analysis revealed that the material failed due to normal tensile overload fracture. The burst test data was used to arrive at fracture mechanics parameters like crack size, gross section area stress and the stress for leak before bursting.     

Diffusion coefficient in polymer solutions

Molecular diffusivity of a solute in a solvent may be determined by measuring the extent of dispersion of solute in solvent flowing in a straight circular tube under the conditions of laminar flow. This simple and rapid method for determination of molecular diffusivity in aquous polymer solutions is discussed. Experimental results show a substantial reduction in the solute diffusivity with increase in polymer concentration.     

Performance models of storage contention in cloud environments

We propose simple models to predict the performance degradation of disk requests due to storage device contention in consolidated virtualized environments. Model parameters can be deduced from measurements obtained inside Virtual Machines (VMs) from a system where a single VM accesses a remote storage server. The parameterized model can then be used to predict the effect of storage contention when multiple VMs are consolidated on the same server. We first propose a trace-driven approach that evaluates a queueing network with fair share scheduling using simulation. The model parameters consider Virtual Machine Monitor level disk access optimizations and rely on a calibration technique. We further present a measurement-based approach that allows a distinct characterization of read/write performance attributes. In particular, we define simple linear prediction models for I/O request mean response times, throughputs and read/write mixes, as well as a simulation model for predicting response time distributions. We found our models to be effective in predicting such quantities across a range of synthetic and emulated application workloads.     

Keeping smart, omnidirectional eyes on you [adaptive panoramic stereovision]

An adaptive panoramic stereo approach for two cooperative mobile platform is presented. There are four key features in the approach: 1) omnidirectional stereovision with an appropriate vertical FOV, and a simple camera calibration method; 2) cooperative mobile platforms for mutual dynamic calibration and best view planning; 3) 3D matching after meaningful object (human subject) extraction; and 4) real-time performance. The integration of omnidirectional vision with mutual awareness and dynamic calibration strategies allows intelligent cooperation between visual agents. This provides an effective way to solve the problems of limited resources, view planning, occlusion, and motion detection of movable robotic platforms. Experiments have shown that this approach is quite promising.     

High performance multi-layer varistor (MLV) from doped ZnO nanopowders by water based tape casting: Rheology,sintering, microstructure and properties

In this work, we report the fabrication of a high performance multi-layer varistor (MLV) via water based tape casting method using novel compositions of nanomaterials. Bi₂O₃, CaO and Co₃O₄ doped ZnO nanopowders were prepared by solution combustion synthesis (SCS) route, calcined at different temperatures (550, 650, 750 and 850?°C) and characterized by TEM, XRD, SEM and AFM. The nanopowder (crystallite size ~30?nm) calcined at 650?°C for 1?h was used as the starting material for MLV fabrication. Compositions of the slurry containing doped ZnO nanopowders, binder and plasticizer in water solvent were optimized for the fabrication of thick film. The rheological properties of the slurries having different solid loadings were analysed and thick films of various thicknesses (50–500?µm) were prepared by varying the feeding rate of tape casting. The film roughness of 38.3?nm for the thick film made from 40?wt% solid slurry was found to be superior compared to other samples due to the presence of reduced crack and shrinkage. MLV fired at 950?°C for 1.5?h exhibited a coefficient of nonlinearity of 18 and breakdown voltage of 291.5?V that yields superior properties compared to commercial MLVs.     

Reactive extraction of itaconic acid using tri‐n‐butyl phosphate and aliquat 336 in sunflower oil as a non‐toxic diluent

Itaconic acid finds a place in various industrial applications. It can be produced by biocultivation in a clean and environment friendly route but recovery of the acid from the dilute stream of the bioreactor is an economic problem. Reactive extraction is a promising method to recover carboxylic acid but suffers from toxicity problems of the diluent and extractant employed. So there is need for a non‐toxic extractant and diluent or a combination of less toxic extractants in a non‐toxic diluent that can recover acid efficiently. Effect of different extractants: tri‐n‐butylphosphate (TBP) (an organophosporous compound) and Aliquat 336 (a quaternary amine) in sunflower oil was studied to find the best extractant–sunflower oil combination. Equilibrium complexation constant, K_E, values of 1.789 and 2.385 m³ kmol^?1, respectively, were obtained for itaconic acid extraction using TBP and Aliquat 336 in sunflower oil. The problem of toxicity in reactive extraction can be reduced by using a natural non‐toxic diluent (sunflower oil) with the extractant. Copyright © 2010 Society of Chemical Industry     

Design of vessels subjected to external pressure

An analytical procedure, developed to simulate the graphic method for the design of vessels subjected to external pressure or vacuum, suggested by the ASME Code, Section VIII, Division 1, is presented in this contribution. A comprehensive computer program based on this method is also presented. The program also covers the design of stiffener rings. The procedure can be easily extended to include other international standards such as the British and German codes, since the method is based on the concept of the number of lobes at collapse. The method produced reproducible results over the entire range of L/D₀ and D₀/t ratios of the code. The deviation observed at any point in this range is less than 0.5% for factor A. The variation in allowable pressure is less than 2%.     

Catalytic packed bed non‐thermal plasma reactor for the extraction of hydrogen from hydrogen sulfide

The decomposition of hydrogen sulfide (H₂S) to hydrogen and sulfur with Al₂O₃, MoO_x/Al₂O₃, CoO_x/Al₂O₃ and NiO/Al₂O₃ packed non‐thermal plasma dielectric barrier discharge reactor was studied. The reaction was carried out with 5‐mm discharge gap during the decomposition of 5 vol.% H₂S at 150 ml/min (STP) flow rate. Typical results indicated the conversion of ~50% at a specific input energy of ~0.92 kJ/l H₂S and 10% (in length) packed reactor showed the best conversion. Among the catalysts studied, MoO_x and CoO_x supported on Al₂O₃ showed high performance, which may be caused by synergy between plasma excitation of the carrier gas molecules and catalytic behaviour of MoO_x and CoO_x. Copyright © 2012 John Wiley & Sons, Ltd.     

Optimal Feature Extraction Using Greedy Approach for Random Image Components and Subspace Approach in Face Recognition

An innovative and uniform framework based on a combination of Gabor wavelets with principal component analysis (PCA) and multiple discriminant analysis (MDA) is presented in this paper. In this framework, features are extracted from the optimal random image components using greedy approach. These feature vectors are then projected to subspaces for dimensionality reduction which is used for solving linear problems. The design of Gabor filters, PCA and MDA are crucial processes used for facial feature extraction. The FERET, ORL and YALE face databases are used to generate the results. Experiments show that optimal random image component selection (ORICS) plus MDA outperforms ORICS and subspace projection approach such as ORICS plus PCA. Our method achieves 96.25%, 99.44% and 100% recognition accuracy on the FERET, ORL and YALE databases for 30% training respectively. This is a considerably improved performance compared with other standard methodologies described in the literature.