Does Ergonomics Improve Product Quality and Reduce Costs? A Review Article

Competition is an ongoing challenge confronting industrial corporations, particularly automobile manufacturing. Striving to improve product quality and productivity, automotive industries have used different quality management approaches, such as reduced variability, total quality management, and lean management, over recent years. Furthermore, incorporating proactive ergonomics such as physical and organizational ergonomics and psychosocial factors into the structure of a company is considered to be a support for productivity and quality. Several studies have shown the effects of ergonomics on better quality. Application of both quality management approaches and ergonomics in an integrated manner in the manufacturing production system is emphasized because they are similar concepts with the same objectives, that is, to improve efficiency. In this study, a comprehensive review was undertaken and 25 studies were reviewed in order to define how integration of an ergonomic approach in the manufacturing production system can reduce defects and improve quality in the production process.     

Integral boundary layer heat transfer modeling for Tehran Research Reactor

In the present work the validity of applying the Boussinesq approximation in the analysis of natural convection heat transfer along nuclear fuel plates with large coolant channel aspect ratios is evaluated. The Boussinesq approximation is introduced into the integral boundary layer equations governing the system to describe the velocity and temperature distributions of the coolant in the cooling channels. The fuel plate temperature is related to the adjacent coolant fluid temperature by a fundamental law in conduction heat transfer. Air and water are considered as fluids. The coolant flow is assumed to be fully developed which is a convenient assumption for coolant channels having large aspect ratios. Obtained results indicate that the Boussinesq approximation is merely applicable over a limited range of coolant channel outlet fluid temperatures. The use of this approximation produces conservative estimation of the critical plate power for air flow and non-conservative estimation of the critical plate power for water flow.     

A Generalized Dimensionless Model for Deep Bed Drying of Paddy

A generalized dimensionless model of paddy drying was developed from a validated partial differential equation (PDE) drying model using the dimensional analysis of Buckingham theorem. This generalized dimensionless model considered all drying parameters in an equation to predict the grain moisture content during the drying process. Statistical parameters, namely, coefficient of determination (R ²), chi-square (χ²), mean relative deviation (MRD), and root mean square error (RMSE), were used as criteria to compare the dimensionless model with a validated PDE model. Based on these calculated parameters, it was concluded that the generalized dimensionless model fitted reasonably well with data from the PDE model and good agreement was found between the generalized dimensionless model and experimental drying data.     

Simulation and Validation of Microwave-Assisted Fluidized Bed Drying of Soybeans

A general mathematical model of heat and mass transfer was developed to simulate the microwave-assisted fluidized bed drying of bulk grain. The model was solved using the well-known Runge-Kutta-Gill method. The model is capable of predicting the moisture content of soybean as well as the drying air parameters (i.e., drying air temperature and moisture content) during drying. The values of mean relative deviation (MRD) were less than 8 and 10% for prediction of grain moisture content and outlet air parameters, respectively, which reflects an acceptable accuracy. In comparison with conventional fluidized bed drying of soybean, microwave-assisted fluidized bed drying led to 83.39–98.07% savings in drying time and 82.07–95.22% savings in specific energy consumption when reducing soybean moisture content from 18.32 to 12% (db).     

Liposome: classification,preparation, and applications

Liposomes, sphere-shaped vesicles consisting of one or more phospholipid bilayers, were first described in the mid-60s. Today, they are a very useful reproduction, reagent, and tool in various scientific disciplines, including mathematics and theoretical physics, biophysics, chemistry, colloid science, biochemistry, and biology. Since then, liposomes have made their way to the market. Among several talented new drug delivery systems, liposomes characterize an advanced technology to deliver active molecules to the site of action, and at present, several formulations are in clinical use. Research on liposome technology has progressed from conventional vesicles to ‘second-generation liposomes’, in which long-circulating liposomes are obtained by modulating the lipid composition, size, and charge of the vesicle. Liposomes with modified surfaces have also been developed using several molecules, such as glycolipids or sialic acid. This paper summarizes exclusively scalable techniques and focuses on strengths, respectively, limitations in respect to industrial applicability and regulatory requirements concerning liposomal drug formulations based on FDA and EMEA documents.     

A facile synthesis of polyaniline/polyethylene glycol/polyaniline terpolymers: preparation of electrospun conducting nanofibers by blending of the terpolymers with polycaprolactone

The water-soluble terpolymers were synthesized in two steps, containing esterification of polyethylene glycol (PEG) and 4-amino benzoic acid without protection of its amino group, then copolymerization of aniline from both end of amine-terminated PEG via an interfacial polymerization method. The chemical structure of triblock copolymers was determined by FTIR and ¹HNMR. The thermal behavior, morphology and electroactivity of terpolymers were also investigated by thermogravimetric analysis, field emission microscope (FESEM) and cyclic voltammetry (CV), respectively. Uniform nanofibers consisting of blends of (PANI)_n-b-PEG-b-(PANI)_n terpolymers and polycaprolactone (PCL) were prepared using electrospinning technique. The FESEM was also used to investigate the electrospun nanofibers produced from different molecular weight of PANI/PEG/PANI terpolymers and PCL (30/70). The CV measurements of blends confirmed the preparation of electroactive nanofibers. The presence of terpolymers enhanced the spinnability of solution and significantly reduced the bead formation. This novel system opens up new and interesting opportunities for applications such as electroactive scaffold for tissue engineering.     

Functional immobilization of a ligand-activated G-protein-coupled receptor

G-protein-coupled receptors (GPCRs) mediate the majority of cellular responses to hormones and neurotransmitters. They are the largest family of receptors in the human genome and constitute the largest class of targets for drug discovery. To facilitate studies of GPCR activation and interactions with other proteins, we developed a simple method to immobilize a functional, detergent-solubilized GPCR on gold and glass surfaces. The beta(2) adrenergic receptor (beta(2)AR), a prototypical GPCR, was purified and labeled with a reporter fluorophore at a conformationally sensitive site. The detergent-soluble fluorescent beta(2)AR was immobilized through its amino-terminal FLAG epitope on a surface layered with biotinylated bovine serum albumin, avidin, and biotinylated M1 antibody. Agonist activation of the beta(2)AR was monitored in real time by fluorescence microscopy. This approach will make it possible to study conformational dynamics of single immobilized receptors and to generate arrays of functional GPCRs for novel high-throughput screening strategies.     

Studying the in vitro corrosion response of nanostructured TaN coatings in Hank's physiological solution

The goal of this research is to determine the effect of N₂ pressure to argon pressure on the microstructural analysis and corrosion behavior of nanostructured TaN deposited coatings using a reactive DC-magnetron sputtering (RDCMS) technique. The samples coated microstructure was studied by the X-ray diffraction (XRD) and scanning electron microscope (SEM), and elemental distribution was studied using energy-dispersive X-ray spectroscopy (EDS). To investigate the corrosion behavior of nanostructured TaN coatings, the potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) tests were performed in Hank's physiological solution. The results of different tests revealed that the coating with a content of 17.6% P_N2/P_Ar consisted of hexagonal and orthorhombic TaN phases and had denser microstructure and free pores. This coating showed superior corrosion behavior in comparison to the other ones. Also, the corrosion resistance of this coating raised by increasing the time of immersion from 48 to 168 h.     

Discrimination of climacteric and non‐climacteric melon fruit at harvest or at the senescence stage by quality traits

BACKGROUND: This paper characterizes the quality traits at harvest and the changes associated with fruit senescence based on fruit physiological behaviour (climacteric or non‐climacteric) found in a collection of near‐isogenic lines (NILs) of melon (Cucumis melo L.). Data from both stages of postharvest development were analyzed by univariate and multivariate statistical analysis. RESULTS: The principal components and random forest analyses of the fruit quality traits allowed the best classification of the NILs by time (harvest, senescence), or by climacteric behaviour at harvest, but not at the senescent stage. The overall quality profile of the non‐climacteric senescent melons was, in general, very different from that of the climacteric ones, and was in accord with a longer storage life. Most of the taste quality traits (individual sugars or sucrose equivalents, titratable acidity and the citric, oxalacetic, glutamic and succinic acids) and the traits related to skin, flesh and juice colour parameters (chroma, hue angle) helped to distinguish the climacteric NILs from the non‐climacteric ones independently of the time considered. CONCLUSIONS: The time had a stronger effect on quality than the physiological behaviour. The discrimination by climacteric or non‐climacteric behaviour was usually better at harvest than at the senescent stage irrespective of the methodology used. Principal component analysis was the best multivariate method to discriminate by time and physiological behaviour followed by random forest and linear discriminant analysis. Copyright © 2009 Society of Chemical Industry     

Identification and resolution of structural and algorithmic singularity in redundancy control of serial manipulations

A major difficulty that has haunted most researchers in the process of optimal redundancy resolution of robotic manipulators is the instability observed in even very simple numerical simulations. This numerical instability is not related to the structurally singular configurations of the manipulators, and in the literature has been referred to as “algorithmic singularity,” “artificial singularity,” or “unavoidable singularity.” In this work, conditions on both structural and algorithmic singularities are studied based on the Singular Value Decomposition of the Jacobian matrix, and, hence, a singularity-free control algorithm for redundant manipulators is developed and resolved as the Lagrange problem of optimal control. It is shown that many well-known methods for optimal redundant manipulation in the literature, including the Extended Jacobian Technique, most of constraint function-based methods, and most of the previously reported methods on global optimization techniques, are all special cases of the formulation provided here. Further, the necessary conditions of the global optimality for this general formulation are derived in explicit form and the source of “algorithmic singularity” is rigorously identified and resolved. © 2995 John Wiley & Sons, Inc.