An Attempt at Preventing Asthenopia Among VDT Workers

We report the results of 3 surveys of visual display terminal (VDT) users who took a minibreak during which they viewed a stereoscopic image of a repeating parallel pattern showing planets. The single image stereogram method employed is called Stretch Eye^TM, and we evaluated the effects of Stretch Eye^TM on asthenopia. An accommodative relaxation of about 1 D was observed in participants while they were gazing at the image. The employees of 2 information technology companies were evaluated according to a visual analogue scale (VAS) for subjective symptoms of asthenopia and eyesight. The results showed that Stretch Eye^TM was effective in easing visual fatigue due to VDT work and it improved eyesight under working conditions.     

苏州垃圾填埋生命周期清单分析

采用理论计算和实测相结合的方法,求得了苏州七子山垃圾填埋埋场的生命周期清单。实践证明,理论计算和实测相结合是清单分析的有效方法,对今后的同类研究具有参考意义。研究中获得的清单包括生活垃圾的收集和运输、垃圾填埋的物耗和能耗,以及每吨填埋垃圾所排放的大气和水污染物的量,并考察了填埋气用于发电后对清单的影响。这些结果可以为众多的产品生命周期评价提供数据支持。     

Japan’s experience of energy saving and business model for low-carbon economy

The purpose of this paper is to clarify the questions concerning stimulation of the innovation and the diffusion of energy saving or low-carbon.To do so,this paper explains using two cases of Japan-energy saving innovation after the Oil Shock and the eco points system.For the case after the oil shock,we explain the energy saving trend after the Oil Shock and the factors statistically.Then we put forward the business model for the low-carbon economy.Furthermore,we analyze the case of the eco points system from 2009-2011 in Japan and explain the significance of the business model for diffusion of the low-carbon products.     

Application of lean flammability limit study and large eddy simulation to burner development for an oxy-fuel combustion system

Previously, we developed a model to predict lean flammability limit L and flame propagation velocity Sb for pulverized coal. In the present paper, we have extended the model to apply it in development of oxy-fuel combustion systems. The basic model consists of two particles. One of the two particles burns first, then, the other particle is ignited by the heat of combustion of the one burning particle. We analyzed at what distance the first burning particle could ignite the next particle, and how fast the first burning particle could ignite the next particle. The model was verified both for air and oxy-fuel combustion conditions. Next, a method to support burner development was examined by using the model. Local Sb and L near the ignition points of the burner could be analyzed from the concentration and temperature profiles of CFD results. Flame stability was judged by the calculated Sb and L profiles, and past results of blow-off limits obtained with actual- and pilot-scale experiments. A DS^®T-burner was developed by Hitachi Power Europe, and installed at the Schwarze Pumpe pilot plant. Combination of the technique and large eddy simulation was applied to confirmation of the system.     

Chronic kidney diseases of uncertain etiology (CKDue) in Sri Lanka: geographic distribution and environmental implications

The increase in the number of chronic kidney disease (CKD) patients from the north central region of Sri Lanka has become a environmental health issue of national concern. Unlike in other countries where long-standing diabetes and hypertension are the leading causes of renal diseases, the majority of CKD patients from this part of Sri Lanka do not show any identifiable cause. As the disease is restricted to a remarkably specific geographical terrain, particularly in the north central dry zone of the country, multidisciplinary in-depth research studies are required to identify possible etiologies and risk factors. During this study, population screening in the prevalent region and outside the region, analysis of geoenvironmental and biochemical samples were carried out. Population screening that was carried out using a multistage sampling technique indicated that the point prevalence of CKD with uncertain etiology is about 2–3% among those above 18 years of age. Drinking water collected from high-prevalent and non-endemic regions was analyzed for their trace and ultratrace element contents, including the nephrotoxic heavy metals Cd and U using ICP-MS. The results indicate that the affected regions contain moderate to high levels of fluoride. The Cd contents in drinking water, rice from affected regions and urine from symptomatic and non-symptomatic patients were much lower indicating that Cd is not a contributing factor for CKD with uncertain etiology in Sri Lanka. Although no single geochemical parameter could be clearly and directly related to the CKD etiology on the basis of the elements determined during this study, it is very likely that the unique hydrogeochemistry of the drinking water is closely associated with the incidence of the disease.     

Risk reduction concept to provide design criteria for Emergency Systems for onshore LNG plants

The functional safety requirement is widely applied in the process plant industry in accordance with the international standards, such as IEC and ISA. The requirement is defined as safety integrity level (SIL) based on the risk reduction concept for protection layers, from original process risk to tolerable risk level. Although the standards specify both, the Prevention System and the Emergency System, as level of protection layers, the standards specify in detail only the use of the Prevention System (i.e., Safety Instrumented System (SIS)). The safety integrity level is not commonly allocated to the Emergency System (e.g., Fire and Gas System, Emergency Shutdown System and Emergency Depressuring System). This is because the required risk reduction can be normally achieved by only the Prevention System (i.e., SIS and Pressure Safety Valve (PSV)). Further, the risk reduction level for the Emergency System is very difficult to be quantified by the actual SIL application (i.e., evaluated based on the single accident scenario, such as an accident from process control deviation), since the escalation scenarios after Loss of Containment (LOC) greatly vary depending on the plant design and equipment. Consequently, there are no clear criteria for evaluating the Emergency System design. This paper aims to provide the functional safety requirement (i.e., required risk reduction level based on IEC 61508 and 61511) as design criteria for the Emergency System.In order to provide clear criteria for the Emergency System evaluation, a risk reduction concept integrated with public’s perception of acceptable risk criteria is proposed and is applied to identify the required safety integrity level for the Emergency System design. Further, to verify the safety integrity levels for the Emergency Systems, the probabilistic model of the Emergency Systems was established considering each Emergency System (e.g., Fire and Gas System, Emergency Shutdown System and Emergency Depressuring System) relation as the Overall Emergency System. This is because the Overall Emergency System can achieve its goal by the combined action of each individual system, including inherent safe design, such as separation distance.The proposed approach applicability was verified by conducting a case study using actual onshore Liquefied Natural Gas Plant data. Further, the design criteria for Emergency Systems for LNG plants are also evaluated by sensitivity analysis.     

NUTRIENT LOAD CHARACTERIZATION FROM INTEGRATED SOURCE DATA FOR THE LOWER MISSISSIPPI RWER1

ABSTRACT: Nutrient data from all available sources for the lower Mississippi River were examined for potential differences among sampling agencies and geographic locations for the period between 1960 and 1998. Monthly means grouped by parameter, sampling location and agency, were calculated and compared as paired sets, excluding those months where data were not available for both sets. Some significant differences were found between various agencies collecting nutrient data on the river, as well as between various stretches of river, especially in the case of phosphorus nutrient data. Results were used to synthesize data sets from which a history of nutrient loading in the Mississippi River was determined. General trends in nitrate+nitrite, total Kjeldahl nitrogen, orthophosphate, total phosphorus and silica loads, as well as changes in nutrient proportions and the specific limiting nutrient (by month) are reported. This study provides a useful summary of contemporary and historical nutrient data that may assist in the evaluation of Mississippi River water quality and its potential effect on the Gulf of Mexico.     

Characterization of semi-volatile organic compounds emitted during heating of nitrogen-containing plastics at low temperature

Because of recent volume increases, appropriate management of plastic recycling, which generates various organic compounds, is required to ensure the chemical safety of the processes. The processing temperature and resin type are the important factors determining both the efficiency of the processes and the emission of chemicals. Therefore, we studied the thermal degradation of various plastics at various temperatures from 70 to 300 °C under oxygen-present conditions to identify the semi-volatile organic compounds (SVOCs) emitted and to understand their thermal behaviors. The plastics examined were nitrogen-containing resins, such as polyamide 6, polyurethane, melamine formaldehyde, urea formaldehyde and acrylonitrile-butadiene-styrene. Major commodity plastics were also investigated for comparison. In total, more than 500 SVOCs were detected as emissions from plastics. While various nitrogen-containing SVOCs were detected from nitrogen-containing resins, the major commodity plastics released only these, which possibly were included as additives. These results indicate that the nitrogen atoms in the SVOCs emitted originated from the resins and additives, and not from ambient air at low temperature. As a result of the detection of raw materials, degradation chemicals and by-products of the polymers in the emissions, we found that the variation in chemical species is dependent on the resins. Additives were also emitted from all the resins, meaning that these chemicals were also released to the environment at the temperature examined. In most cases, the numbers and concentrations of SVOCs increased with increasing heating temperature. The variation of thermal behaviors of SVOCs was related to the origins and chemical species of SVOCs.     

Changes in gonadal development,androgenic gland cell structure,and hemolymph vitellogenin levels during male phase and sex change in laboratory-maintained protandric shrimp, <Emphasis Type="Italic">Pandalus hypsinotus</Emphasis> (Crustacea: Caridea: Pandalidae)

Most pandalid shrimps show protandric hermaphroditism, and male sexual differentiation is considered to be controlled by the androgenic gland. In the present study, we examined the histology of gonadal development during the male phase and sex change and the involvement of the androgenic gland in regulating male reproduction in laboratory-maintained Pandalus hypsinotus. Juvenile shrimps developed testicular tissues in the peripheral part of gonads during the age of 16–31 months and produced spermatozoa between 34 and 36 months. After reaching sexual maturity, male shrimps exhibited seasonal testicular development: active production of spermatozoa (February–May), disappearance of spermatozoa (spent, April–June), increase of spermatocytes (May–November), appearance of spermatids and spermatozoa in the gonads (November–February). The androgenic gland cells became larger and the rough endoplasmic reticulum in the cytoplasm developed at male sexual maturity. The cell structure shows that the androgenic gland hormone is a peptide. Furthermore, bilateral eyestalk ablation on immature male shrimps induced hypertrophy of the androgenic gland and acceleration of male sexual maturation. These results indicate the involvement of androgenic gland hormone and some eyestalk factor in regulating male sexual maturation. Over a 1-year laboratory-rearing period, some male shrimps (16.7%) changed sex. In transitional shrimps, testicular tissues in the gonads and androgenic glands degenerated; on the other hand, oocytes started yolk protein accumulation and hemolymph vitellogenin levels became high. These results suggest that androgenic gland degeneration is a trigger for sex change and that the vitellogenin level is a useful marker for sex change.     

Participation of the C-type hemolymph lectin in mineralization of the acorn barnacle Megabalanus rosa

BRA-2, a major C-type lectin in the hemolymph of the acorn barnacle Megabalanus rosa was detected in shell-associated proteins. Immobilized BRA-2 promoted CaCO₃ crystallization as determined by an in vitro pH-drift mineralization assay. In nature, calcification occurs as wound repair in M. rosa after breakage of the shell plate. To observe this phenomenon, we inserted a rubber cube inside the mantle cavity of M. rosa through the basal plate, and kept the organisms in a tank for several weeks. The rubber cube was covered first with brownish-colored material, probably a melanin, and then with CaCO₃ 5 weeks after the insertion. In the CaCO₃-associated proteins, BRA-3, a minor component of M. rosa hemolymph lectins, was present in addition to BRA-2. The presence of both the lectins and their ligands on the hemocyte was also observed. These results suggest that the C-type lectins of the M. rosa hemolymph participate in mineralization as well as defense in these organisms.