NEWS

Abstract

Co-integration theory has been employed in this paper and Granger causes are found between urbanization rate and GDP, between capital stock and GDP. Scenario analysis of GDP is performed using the GDP model established in the paper. The energy consumptions in Germany, Japan and other developed countries are analyzed and compared with the energy consumption in China. Environmental friendly scenario of energy demand and CO₂ emissions for sustainable China has been formed based on the results of comparison. Under environmental friendly scenario, the primary energy consumption will be 4.31 billion ton coal equivalence (tce) and CO₂ emissions will be 1.854 billion t-c in 2050; energy per capital will be 3.06 tce that is 1.8 times of energy consumed in 2005 in China and 51% of consumed energy per capital in Japan in 2003. In 2050, the energy requirement of unit GDP will be 20% lower than that of Germany in 2003, but will be still 37% higher than that in Japan in 2003. It is certain that to fulfill the environmental friendly Scenario of energy demand and CO₂ emissions is a difficult task and it needs long term efforts of the whole society, not only in production sectors but also in service and household sectors.     

Stagnant surface water bodies (SSWBs) as an alternative water resource for the Chittagong metropolitan area of Bangladesh: physicochemical characterization in terms of water quality indices

The concern over ensuing freshwater scarcity has forced the developing countries to delve for alternative water resources. In this study, we examined the potential of stagnant surface water bodies (SSWBs) as alternative freshwater resources in the densely populated Chittagong metropolitan area (CMPA) of Bangladesh??where there is an acute shortage of urban freshwater supply. Water samples were collected at 1-month intervals for a period of 1 year from 12 stations distributed over the whole metropolis. Samples were analyzed for pH, water temperature (WTemp), turbidity, electrical conductivity (EC), total dissolved solids, total solids, total hardness, dissolved oxygen (DO), chloride, orthophosphates, ammonia, total coliforms (TC), and trace metal (Cd, Cr, Cu, Pb, As, and Fe) concentrations. Based on these parameters, different types of water quality indices (WQIs) were deduced. WQIs showed most of CMPA-SSWBs as good or medium quality water bodies, while none were categorized as bad. Moreover, it was observed that the minimal water quality index (WQI_m), computed using five parameters: WTemp, pH, DO, EC, and turbidity, gave a reliable estimate of water quality. The WQI_m gave similar results in 72% of the cases compared with other WQIs that were based on larger set of parameters. Based on our finding, we suggest the wider use WQI_m in developing countries for assessing health of SSWBs, as it will minimize the analytical cost to overcome the budget constraints involved in this kind of evaluations. It was observed that except turbidity and TC content, all other quality parameters fluctuated within the limit of the World Health Organization suggested standards for drinking water. From our findings, we concluded that if the turbidity and TC content of water from SSWBs in CMPA are taken care of, they will become good candidates as alternative water resources all round the year.     

Characteristic Air Temperature Distributions Observed in Summer and Winter in Urban Area in Japan

The air temperature distributions in August (summer) and December (winter) were measured in an approximately 15 × 15-km urban area in Hyogo Prefecture, Japan, in order to study the spatial distribution of the air temperature and to propose effective measures against the heat island phenomenon. The air temperature was measured mainly by using thermometer shelters installed in an elementary school and a junior high school. The characteristic air temperature distribution depended on the season. The air temperature was higher inland than in the coastal region in August but was higher in the coastal region in December. The air temperature index indicated that the area where higher air temperatures would most likely appear was 5 to 10 km inland from the coast in August and around the coast in December. The seasonal air temperature distribution was presumably due to the strength of solar radiation and anthropogenic exhaust heat.     

The effects of current water management practices on methane emissions in Japanese rice cultivation

Cultivated wetland rice fields are a source of methane (CH₄) emissions. To estimate CH₄ emissions and develop policies to reduce such emissions, information on water management at the farm level is crucial. It is known that farmers implement midseason drainage (MD) to increase rice yields and save water. However, little is known about whether MD is carried out in soils where CH₄ emissions are high and how part-time status will influence management. The objective of this study is to identify factors that determine MD implementation using a binomial logistic regression model based on a farm-level survey in Japan and to indicate possible changes in estimates of CH₄ emissions, accounting for current water management practices. The implementation rates were significantly higher where the soil types were classified as having the potential for high CH₄ emissions. Under current water management practices, the duration of MD and the percentage of continuous flooding were 5 to 7 days longer and approximately 7 % higher, respectively, than the values used by the Greenhouse Gas Inventory Office of Japan, which in turn are used to report greenhouse gas emissions to the United Nations Framework Convention on Climate Change. By accounting for current water conditions with the Tier 2 method, this study indicates that national estimates of CH₄ emissions from rice straw application areas could be lowered by 12.7 %. These results may contribute to the development of a mitigation policy that will help to further reduce CH₄ emissions.     

Relationship between the growth and survival of larval Pacific bluefin tuna, Thunnus orientalis

We tested the hypothesis that a large body size and rapid growth rate affect the survival of larval Pacific bluefin tuna, Thunnus orientalis (PBT), and analyzed larval growth in relation to environmental conditions. Seven high density larval patches of PBT were tracked with reference buoys in the northwestern Pacific Ocean for 28–171 h in May–June from 2004 to 2008. The otolith radii and daily growth rates of the survivor larvae (collected on later tracking days of each tracking session) tended to be larger and more rapid, respectively, than those of original larvae (collected on earlier tracking days). A large body size was found to positively affect the survival of larval PBT, as did a rapid growth rate, even at an early larval stage (7 days after hatching). Generalized linear modeling showed that the otolith radius was influenced positively by the sea temperature, stratification parameter and food density, while the growth rate was influenced positively by the sea temperature and food density.     

Serial variations of trace metal concentrations in aquatic insect Stenopsyche marmorata

Caddisfly larvae (Stenopsyche marmorata) instar V, periphyton, sediment and river water at a non‐contaminated upstream site, a metallic contaminated downstream site, and industrial wasterwater which caused the metallic contamination were collected once a month for 21 months. Nickel (Ni), copper (Cu), zinc (Zn), and lead (Pb) concentrations in these samples were measured. Significant serial variations of the 4 metal concentrations in the larvae showed a seasonal tendency at the upstream site but not at the downstream site. The larvae more clearly indicated the influence of industrial wastewater than periphyton. As the larvae of Stenopsyche marmorata could be collected throughout the year, this larva is useful for monitoring trace metal contamination in rivers.     

Foliage profiles of individual trees determine competition,self-thinning,biomass and NPP of a Cryptomeria japonica forest stand: A simulation study based on a stand-scale process-based forest model

A simulation study was carried out to investigate simultaneously the effects of eco-physiological parameters on competitive asymmetry, self-thinning, stand biomass and NPP in a temperate forest using an atmosphere–vegetation dynamics interactive model (MINoSGI). In this study, we selected three eco-physiological relevant parameters as foliage profiles (i.e. vertical distribution of leaf area density) of individual trees (distribution pattern is described by the parameter η), biomass allocation pattern in individual tree growth (χ) and the maximum carboxylation velocity (V_max). The position of the maximal leaf area density shifts upward in the canopy with increasing η. For scenarios with η < 4 (foliage concentrated in the lowest canopy layer) or η > 12 (foliage concentrated in the uppermost canopy layer), a low degree of competitive asymmetry was produced. These scenarios resulted in the survival of subordinate trees due to a brighter lower canopy environment when η < 4 or the generation of spatially separated foliage profiles between dominant and subordinate trees when η > 12. In contrast, competition between trees was most asymmetric when 4 ≤ η ≤ 12 (vertically widespread foliage profile in the canopy), especially when η = 8. In such cases, vertically widespread foliage of dominant trees lowered the opportunity of light acquisition for subordinate trees and reduced their carbon gain. The resulting reduction in carbon gain of subordinate trees yielded a higher degree of competitive asymmetry and ultimately higher mortality of subordinate trees. It was also shown that 4 ≤ η ≤ 12 generated higher self-thinning speed, smaller accumulated NPP, litter-fall and potential stand biomass as compared with the scenarios with η < 4 or η > 12. In contrast, our simulation revealed small effects of χ or V_max on the above-mentioned variables as compared with those of η. In particular, it is notable that greater V_max would not produce greater potential stand biomass and accumulated NPP although it has been thought that physiological parameters relevant to photosynthesis such as V_max influence dynamic changes in forest stand biomass and NPP (e.g. the greater the V_max, the greater the NPP). Overall, it is suggested that foliage profiles rather than biomass allocation or maximum carboxylation velocity greatly govern forest dynamics, stand biomass, NPP and litter-fall.     

Investigation of perfluoroalkyl carboxylic and sulfonic acids in leachates from industrial and municipal solid waste landfills,and their treated waters and effluents from their closest leachate treatment plants

Journal of Material Cycles and Waste Management - Per- and polyfluoroalkyl substances (PFASs) are used in products, such as aqueous film-forming foam and fluorochemical surfactants, because of...     

Evaluating the strength development of mortar using clinker fine aggregate with a combination of fly ash and its inhibitory effects on alkali–silica reaction and delayed ettringite formation

The aggregate composed of cement clinker, an intermediate cement product, improves strength development and mass transfer resistance of concrete. Fly ash (FA) is a supplementary cementitious material that can be substituted by cement. This study investigated the strength development of highly FA-substituted mortar mixed with cement clinker fine aggregate (CL) and tested its inhibitory effect against the alkali–silica reaction (ASR). In addition to these, this study provides the testing results of evaluating the effects of using cement clinker fine aggregate on delayed ettringite formation (DEF), which can be problematic for precast concrete products. The study results revealed that at 91 days of age, in the case of 80% replacement ratio of fly ash to cement, using CL exhibited similar strength development as mortar with limestone fine aggregate and no FA substitution. Furthermore, mortars with 70% and 80% FA substitution did not exhibit clear ASR-induced expansion even at 182 days of age. Lastly, mortar using clinker fine aggregate could suppress DEF-induced expansion at 182 days of age, which was similar to the effect obtained using FA. These results can promote the utilization of CL resources for concrete and using clinker as fine aggregate in precast concrete products.

     

Efficient depolymerization and chemical conversion of polyamide 66 to 1,6-hexanediol

Journal of Material Cycles and Waste Management - Polyamide 66 was efficiently depolymerized and chemically converted by treatment with supercritical MeOH in the presence of glycolic acid. The...