Occupational injuries and sick leaves in household moving works

Background. This study is concerned with household moving works and the characteristics of occupational injuries and sick leaves in each step of the moving process. Methods. Accident data for 392 occupational accidents were categorized by the moving processes in which the accidents occurred, and possible incidents and sick leaves were assessed for each moving process and hazard factor. Results. Accidents occurring during specific moving processes showed different characteristics depending on the type of accident and agency of accidents. The most critical form in the level of risk management was falls from a height in the ‘lifting by ladder truck’ process. Incidents ranked as a ‘High’ level of risk management were in the forms of slips, being struck by objects and musculoskeletal disorders in the ‘manual materials handling’ process. Also, falls in ‘loading/unloading’, being struck by objects during ‘lifting by ladder truck’ and driving accidents in the process of ‘transport’ were ranked ‘High’. Conclusion. The findings of this study can be used to develop more effective accident prevention policy reflecting different circumstances and conditions to reduce occupational accidents in household moving works.     

Effects of load carriage and work boots on lower limb kinematics of industrial workers

Load and footwear condition are two crucial elements varying the kinematic responses during walking, which probably lead to chronic injury. Fifteen healthy male individuals with no obvious gait abnormalities participated in this study. Apart from a no-load condition, four external load conditions with two load levels were investigated. Work boots were compared with running shoes to determine footwear effects. Significant impacts were found for lower limb range of motion at certain joints when carrying loads. A greater hip and ankle flexion–extension while wearing the work boots indicated that participants needed to lift the leg higher to complete toe clearance off the walking surface. Work boots also increased the vertical excursion of the center of body mass, which may impact body balance and induce falling. No significant influencing pattern of carrying modes was found, which was probably due to the light load and relatively stable mode of shoulder carrying.     

A comprehensive empirical investigation of the relationships among variables of the groupthink model

Although a quarter of a century has passed since Janis proposed his groupthink model in 1972, there is very little consensus among researchers on the validity of the model. This study conducted a comprehensive empirical investigation of Janis's model by including all 24 variables in the research. Data were collected from 64 four‐person ad hoc groups; the group discussion sessions were videotaped and content‐analysed afterwards. Statistical analyses revealed that Janis's predictions about the causal relationship among four groups of variables in the model are only partially correct; when the effects of individual independent variables on the dependent variables were tested, Janis's predictions were confirmed in only two out of 23 cases. Copyright © 2000 John Wiley & Sons, Ltd.     

Classifying environmentally significant urban land uses with satellite imagery

We investigated Bayesian networks to classify urban land use from satellite imagery. Landsat Enhanced Thematic Mapper Plus (ETM(+)) images were used for the classification in two study areas: (1) Marina del Rey and its vicinity in the Santa Monica Bay Watershed, CA and (2) drainage basins adjacent to the Sweetwater Reservoir in San Diego, CA. Bayesian networks provided 80-95% classification accuracy for urban land use using four different classification systems. The classifications were robust with small training data sets with normal and reduced radiometric resolution. The networks needed only 5% of the total data (i.e., 1500 pixels) for sample size and only 5- or 6-bit information for accurate classification. The network explicitly showed the relationship among variables from its structure and was also capable of utilizing information from non-spectral data. The classification can be used to provide timely and inexpensive land use information over large areas for environmental purposes such as estimating stormwater pollutant loads.     

Environmental and economic feasibility study of a total wastewater treatment network system

The synthesis of distributed wastewater treatment plants (WTPs) has been studied to reduce capital and operating costs associated with wastewater treatment. In this study, the environmental and economic feasibility of a total wastewater treatment network system (TWTNS) including distributed and terminal WTPs was estimated using life cycle assessment (LCA) and life cycle costing (LCC) methods. Wastewater sources and existing distributed and terminal WTPs in an iron and steel plant were networked. The TWTNS was generated from the optimal solution to a mathematical optimization model and compared to a conventional wastewater treatment system (CWTS). The environmental effect scores of the TWTNS were from 29.6% to 68.3% higher than those of the CWTS because of higher electricity consumption required to pump wastewater to the networked WTPs. However, the life cycle cost of the TWTNS was lower than that of the CWTS by 10.1% because of the decrease of the labor cost resulting from the closing of three distributed WTPs. Overall, the TWTNS was no more eco-efficient than the CWTS because the increase of environmental burdens outweighed the decrease of economic costs.     

Characteristics of malodor pollutants and aromatic VOCs around an urban valley in Korea

In this study, the environmental behavior of malodor pollutants (MPs) [including reduced sulfur compounds (RSCs)] and aromatic volatile organic compounds (AVOCs) were investigated around urban valley areas during several field campaigns (February through December 2006). The MPs measured in the study area include the RSCs (H(2)S, CH(3)SH, DMS, and DMDS), ammonia (NH(3)), and styrene (STY); the AVOCs include benzene (BEN), toluene (TOL), ethylbenzene (EB), m,p-xylene (MPX), and o-xylene (OX). The variation of most MP concentrations (except for DMDS) was found to be larger than that of AVOCs. It was found that STY (2,346 +/- 4,867 ppbv) was the most dominant MP followed by NH(3) (447 +/- 285), CH(3)SH (16 +/- 41), and the others (<8). The magnitude of AVOCs was found in the following descending order: TOL (1.4 +/- 2.2 ppbv), EB (1.0 +/- 2.1), MPX (0.9 +/- 2.0), and the others (<0.8). The concentration levels of most MPs on industrial (I) and downwind (D) sites were up to an order of magnitude higher than those at non-industrial (N) and upwind (U) sites. For most AVOCs, the former was ~3 times higher than the latter. For malodor intensity in RSCs, CH(3)SH was the dominant contributor. The concentration difference in target compounds between the sites/periods is likely to be caused by the combined effects such as emission sources, geographical features (e.g., semi-closed topography), and meteorological conditions (e.g., wind directions) in and outside the urban valley.     

Characterizations of biochar from hydrothermal carbonization of exhausted coffee residue

The aim of this study was to produce renewable energy from exhausted coffee residue, which is a form of biomass. As coffee preference continues to increase, the importation of coffee beans has been increasing sharply. However, the amount of coffee that is actually consumed is only about 0.2% of coffee beans, while the spent coffee beans are discarded in the form of exhausted coffee residue. Hydrothermal carbonization is a method of producing an improved fuel from renewable energy sources by changing the physical and chemical properties of biochars. Biochars were obtained from a variety of reaction temperatures during hydrothermal carbonization and analyzed using elemental analysis, ultimate analysis, and calorific value measurement. The atomic C/O and C/H ratios of all obtained biochars decreased and were found to be similar to those of lignite and sub-bituminous coal. The highest energy recovery efficiency of biochar indicates that the optimum reaction temperature for hydrothermal carbonization was between 210 and 240 °C, which produced biochars with calorific value of approximately 26–27 MJ/kg. The spectra of biochars obtained from Fourier transform infrared spectroscopy (FTIR) showed fewer C–O and aliphatic C–H functional groups, but more carbonyl C=O functional groups and aliphatic CH _x groups. The results of this study indicate that hydrothermal carbonization can be used as an effective means to generate highly energy-efficient renewable fuel resources from coffee residue. The thermogravimetric analysis provided the changing combustion characteristics due to increased fixed carbon content.     

Identification of black plastics realized with the aid of Raman spectroscopy and fuzzy radial basis function neural networks classifier

To accomplish the effective classifier and secure the accurate classification capabilities of black plastics, a comprehensive design methodology of fuzzy radial basis function neural networks is developed with the aid of principal component analysis and particle swarm optimization. Plastics recycling is the competitive method which can deal with the shortage of natural resource. To recycle and reuse the waste plastics, this study is given as the key issue to identify and classify waste plastics by resin type such as polyethylene terephthalate, polypropylene, polystyrene, etc. To complement the weak points of recognition and classification of the near-infrared radiation equipment, Raman spectroscopy is used to obtain qualitative as well as quantitative analysis of black plastics. To improve the identification performance of black plastics, an intelligent computing algorithm such as fuzzy radial basis function neural networks classifier and preprocessing algorithm as principal component analysis are applied to analyze and classify the obtained spectrum of black plastics. Finally, to optimize the structure as well as parameters of fuzzy radial basis function neural networks, particle swarm optimization technique is used. The obtained experimental results show that the proposed network architecture exhibits high classification capabilities in practical applications.     

Biogas productivity of algal residues from bioethanol production

Journal of Material Cycles and Waste Management - The purpose of this study was to investigate biogas productivity of algal residues from bioethanol production. Pre-treatment based on enzyme was...