Effects of Temperature–Climate Patterns on the Production of Some Competitive Species on Grounds of Modelling

Climate change has serious effects on the setting up and the operation of natural ecosystems. Small increase in temperature could cause rise in the amount of some species or potential disappearance of others. During our researches, the dispersion of the species and biomass production of a theoretical ecosystem were examined on the effect of the temperature–climate change. The answers of the ecosystems which are given to the climate change could be described by means of global climate modelling and dynamic vegetation models. The examination of the operation of the ecosystems is only possible in huge centres on supercomputers because of the number and the complexity of the calculation. The number of the calculation could be decreased to the level of a PC by considering the temperature and the reproduction during modelling a theoretical ecosystem, and several important theoretical questions could be answered.     

Biological treatment of anaerobically digested palm oil mill effluent (POME) using a Lab-Scale Sequencing Batch Reactor (SBR)

The production of highly polluting palm oil mill effluent (POME) has resulted in serious environmental hazards. While anaerobic digestion is widely accepted as an effective method for the treatment of POME, anaerobic treatment of POME alone has difficulty meeting discharge limits due to the high organic strength of POME. Hence, subsequent post-treatment following aerobic treatment is vital to meet the discharge limits. The objective of the present study is to investigate the aerobic treatment of anaerobically digested POME by using a sequencing batch reactor (SBR). The SBR performance was assessed by measuring Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD) and Total Suspended Solids (TSS) removal as well as Sludge Volume Index (SVI). The operating pH and dissolved oxygen concentrations were found to be 8.25–9.14 and 1.5–6.4 mg/L, respectively, throughout the experiment. The experimental results demonstrate that MLVSS, OLR and sludge loading rate (SLR) play a significant role in the organic removal efficiency of SBR systems and therefore, further investigation on these parameters was conducted to attain optimum SBR performance. Maximum COD (95–96%), BOD (97–98%) and TSS (98–99%) removal efficiencies were achieved at optimum OLR, SLR and MLVSS concentration ranges of 1.8–4.2 kg COD/m³ day, 2.5–4.6 kg TSS/m³ day and 22,000–25,000 mg/L, respectively. The effluent quality remained stable and complied with the discharge limit. At the same time, the sludge showed good settling properties with average SVI of 65. It is envisaged that the SBR process could complement the anaerobic treatment to produce final treated effluent which meets the discharge limit.     

Measuring bulky waste arisings in Hong Kong

All too often, waste authorities either assume that they know enough about their bulky waste stream or that it is too insignificant to deserve attention. In this paper, we use Hong Kong as an example to illustrate that official bulky waste figures can actually be very different from the reality and therefore important waste management decisions made based on such statistics may be wrong too. This study is also the first attempt in Hong Kong to outline the composition of bulky waste.It was found that about 342 tonnes/day of wood waste were omitted by official statistics owing to incomplete records on actual bulky waste flow. This is more than enough to provide all the feedstock needed for one regular-sized wood waste recycling facility in Hong Kong. In addition, the proportion of bulky waste in the municipal solid waste (MSW) streams in Hong Kong should be about 6.1% instead of the officially stated 1.43%. Admittedly, there are limitations with this study. Yet, present findings are suggestive of significant MSW data distortion in Hong Kong.     

Characteristics of organic matter in PM2.5 in Shanghai

Solvent extractable organic compounds (SEOC), organic carbon, elemental carbon and water soluble organic carbon (WSOC) in PM(2.5) samples collected in Shanghai, China in 2002 and 2003 were measured to determine the composition and sources of the organic matter in atmospheric aerosols. Distinct seasonal variations were detected with higher concentrations of organic matter in winter. The concentration of total carbon of about 20 microg m(-3) in winter was about three times the summer value. About 30% of the total carbon was water soluble. Unresolved complex mixture (UCM) and fatty acids were the most abundant components quantified in SEOC, similar to other Chinese cities previously studied. High ratio of UCM to n-alkanes (U:R) and the composition of triterpanes indicated that engine exhaust was a major source of the airborne organic matter. Emissions from coal burning had more impact in the rural areas, according to the U:R value and PAHs composition. Chemical mass balance (CMB) modeling shows that about half of the organic carbon was from engine exhaust and about 15% was from coal burning. No clear spatial variation in the concentration of the organic matter was found between urban and rural areas. Our results showed that due to the rapid urbanization and relocation of industrial plants from urban areas to rural areas in the past 20 years, air pollution in rural areas is becoming a serious problem in Shanghai and the Yangtze River delta.     

Characterizing driving patterns for Zhuhai for traffic emissions estimation

Zhuhai, a relatively less developed city on the western coast of the Pearl River Delta (PRD) of China, is planning to undergo major development in coming years. A Hong Kong-Zhuhai-Macao Bridge project has been approved by the Central Government of China. The project will have great impact on the driving pattern and vehicular emissions to the city. This baseline study collected speed-time data of two instrumented private cars in morning and evening periods, as well as a daytime nonpeak period of >10 consecutive days in the spring and winter of 2003. The authors used the microwave speed sensor and global positioning system installed in the instrumented cars and used car-chasing technique to perform the data collection. They used the statistical package SPSS to assess the consistency, as well as to evaluate the variability of the data. Nine parameters, namely, average speed, average running speed, average acceleration rate, average deceleration rate, mean length of a driving period, time proportions of driving modes, average number of acceleration-deceleration changes, root mean square acceleration, and positive acceleration kinetic energy are calculated to represent the driving characteristics. A driving cycle for private cars was developed. If emission tests were conducted using the Zhuhai driving cycle, the level of vehicle emissions measured is likely to be in between that of the Federal Test Procedure (FTP) cycle and the Melbourne Peak cycle.     

Measuring safety climate in elderly homes

IntroductionProvision of a valid and reliable safety climate dimension brings enormous benefits to the elderly home sector. The aim of the present study was to make use of the safety climate instrument developed by OSHC to measure the safety perceptions of employees in elderly homes such that the factor structure of the safety climate dimensions of elderly homes could be explored.MethodIn 2010, surveys by mustering on site method were administered in 27 elderly homes that had participated in the "Hong Kong Safe and Healthy Residential Care Home Accreditation Scheme" organized by the Occupational Safety and Health Council.ResultsSix hundred and fifty-one surveys were returned with a response rate of 54.3%. To examine the factor structure of safety climate dimensions in our study, an exploratory factor analysis (EFA) using principal components analysis method was conducted to identify the underlying factors. The results of the modified seven-factor's safety climate structure extracted from 35 items better reflected the safety climate dimensions of elderly homes. The Cronbach alpha range for this study (0.655 to 0.851) indicated good internal consistency among the seven-factor structure. Responses from managerial level, supervisory and professional level, and front-line staff were analyzed to come up with the suggestion on effective ways of improving the safety culture of elderly homes. The overall results showed that managers generally gave positive responses in the factors evaluated, such as "management commitment and concern to safety," "perception of work risks and some contributory influences," "safety communication and awareness," and "safe working attitude and participation." Supervisors / professionals, and frontline level staff on the other hand, have less positive responses. The result of the lowest score in the factors - "perception of safety rules and procedures" underlined the importance of the relevance and practicability of safety rules and procedures.ConclusionThe modified OSHC safety climate tool provided better evidence of structural validity and reliability for use by elderly homes' decision makers as an indicator of employee perception of safety in their institution.Impact on industryThe findings and suggestions in the study provide useful information for the management, supervisors/professionals and frontline level staff to cultivate the safety culture in the elderly home sector. Most important, elderly homes can use the modified safety climate scale to identify problem areas in their safety culture and safety management practices and then target these for intervention.     

Using process stream index (PSI) to assess inherent safety level during preliminary design stage

In the current practice, safety assessment is conducted once the process design has been completed. At this stage of design, the freedom to change the conceptual design is very limited and whatever strategies to be implemented will only control the hazard. This paper reports on the development of inherent safety index known as a process stream index (PSI) for inherent safety level assessment at preliminary design stage from the perspective of an explosion. The aim for PSI is to calculate, compare and prioritize the level of inherent safety of process streams during simulation work that influences the explosion. By prioritizing the streams based on the potential for the explosion, the design engineers can easily identify the critical streams to be considered for improvement in order to avoid or minimize explosion hazards. An enhancement technique to reflect the contribution of the individual components in the mixture is introduced, which provide significant contribution to the ranking of inherent safety level of process streams. The assessment of inherent safety level using PSI is demonstrated by case studies of HYSYS simulation for Acrylic Acid Plant and Natural Gas Liquid (NGL) plant.     

The guessing of mine safety signs meaning: effects of user factors and cognitive sign features

This study investigated the effects of user factors and cognitive sign features on the guessability of mine safety signs. Sixty na?ve participants guessed the meanings and rated the cognitive sign features of 42 Mainland Chinese mine safety signs. The results showed that some user factors were significant predictors of guessing performance, while some were not. As expected, guessability scores varied significantly with the cognitive sign features of familiarity, concreteness, simplicity, meaningfulness and semantic closeness. The findings emphasize the need to create awareness of the importance of mine safety and promote understanding of mine safety sign meanings amongst people in their work environments. To design more user-friendly mine safety signs, industrial designers should develop and evaluate signs with consideration of the significant user factors and the 5 sign features tested here.     

Reproductive impairment of sea urchins upon chronic exposure to cadmium. Part I: Effects on gamete quality

Successful reproduction is a determining factor for species survival. Pollution may impair reproductive success of adults through effects on gamete quality. Reproductive impairment of the sea urchin Anthocidaris crassispina upon chronic (4 weeks) exposure to 0.01 and 0.1 mg l-1 Cd2+ was investigated. Criteria used for assessing gamete quality included sperm motility, egg morphology, fertilization rate and dynamics of first cleavage. A dose-response relationship was found between Cd2+ levels and changes in sperm motility, and percentage fertilization. Sperm motility, measured by computer-assisted sperm analysis, indicated that percent motile sperm, velocities, and percent sperm with normal trajectory were significantly affected by chronic exposure to > or = 0.1 mg l-1 Cd2+. A decline in sperm motility was also accompanied by a decrease in fertilization success of sea urchin sperm. Width/height ratio of sea urchin eggs was not affected by cadmium, but larger egg sizes were found when sea urchins were exposed to 0.1 mg l-1 Cd2+. Male sea urchins exposed to Cd2+ produced poorer quality sperm, as indicated by a lower percent fertilization and lower cleavage rate, implying that male sea urchins were more sensitive than females to chronic Cd2+ exposure. Results of the present study provide an explanation of reproductive impairment in marine invertebrates upon chronic exposure to Cd2+.