Rebound effect across seasons: evidence from the replacement of air conditioners in Japan

Environmental Economics and Policy Studies - Switching to more energy-efficient appliances may lead to higher energy demand. This phenomenon is known as the rebound effect, which may lead to less...     

Decomposition of dichloromethane and in situ alkali absorption of resulting halogenated products by a packed-bed non-thermal plasma reactor

For an effective decomposition and removal of organic halogenated compounds, a packed-bed non-thermal plasma reactor with in situ absorption of the resulting halogenated products by alkaline sorbent incorporated was proposed. In the plasma reactor, α-Al₂O₃ particles of 1 and 3 mm (mean particle diameter) were packed as solid dielectric medium to enhance the plasma power density in the reactor. Further, alkaline sorbent of Ca(OH)₂ was doped onto the surface of α-Al₂O₃ particles, in order to remove halogenated products by in situ absorption with Ca(OH)₂. A high-voltage and high-frequency pulsed power of −15 to 15 kV and 1 kHz was applied to the wire electrode of the plasma reactor by means of a DC power source. In the present study, as the sample of an organic halogenated compound that is most popularly used, we selected dichloromethane (CH₂Cl₂), and 500 ppm of the initial concentration of CH₂Cl₂ was fed into the reactor accompanied by air at a fixed flow rate of 500 × 10⁻⁶ m³ min⁻¹ at room temperature. As a result, it was recognized that the amount of CH₂Cl₂ decomposed by non-thermal plasma in an α-Al₂O₃ particle bed increased with an increase in plasma input power. The ratio of decomposition of CH₂Cl₂ was almost 100% at 13 kV of electric power and 1 kHz frequency, and CO₂, CH₃Cl, COCl₂, HCl, and Cl₂ were observed as the major reaction products. On the other hand, when CH₂Cl₂ was introduced into the plasma reactor where α-Al₂O₃ particles doped with Ca(OH)₂ were packed, the ratio of decomposition of CH₂Cl₂ became higher, compared to the case that α-Al₂O₃ particles were not doped with Ca(OH)₂. Moreover, there were no halogenated by-product gases detected in the outlet gas from the reactor. As the solid reaction products, CaClOH and Ca(ClO)₂·4H₂O were detected on Ca(OH)₂ by X-ray diffraction. From these findings, it was recognized that CH₂Cl₂ was decomposed more effectively without producing unwanted harmful halogenated by-products in the proposed non-thermal plasma reactor where α-Al₂O₃ particles doped with Ca(OH)₂ sorbent were packed.     

Metals leachability from medical waste incinerator fly ash: A case study on particle size comparison

This paper presents the results from a study of metals leachability of medical waste incinerator fly ash in Japan on the basis of particle size. Sequential extraction and Toxicity Characteristic Leaching Procedure (TCLP) analysis were carried out in order to quantify the leaching amount of metals in each categorized particle size. Sequential extraction was also subjected to identify the preference of binding matrix of metals. The results of sequential extraction showed an increase both exchangeable and carbonate associated chromium concentrations in the bigger particle size fractions. Likewise, concentrations of carbonate matrix of arsenic and tin tended to increase in the bigger particle size fractions. In contrast, exchangeable associated cadmium as well as both exchangeable and carbonate matrices of barium were found higher in the smaller particle size fractions. However, no correlation was found in Kendal-tau correlation analysis between particle size of the ash and metals leachability of the TCLP.     

Distribution patterns of larval myctophid fishes in the transition region of the western North Pacific

We examined the species composition and horizontal distribution of myctophid fish larvae in the transition region of the western North Pacific during the early summer. In total, 4,760 myctophid larvae were collected at 44 stations; 18 species of myctophids from 15 genera were collected, and the 8 most abundant species accounted for >95% of larvae. The distribution patterns of these larvae were well defined by the hydrographic structures of the study area including the Oyashio and Kuroshio fronts, the Subarctic Boundary, and a warm core ring. The horizontal distribution patterns of the eight dominant species were categorized into three groups: northern transition water (Stenobrachius nannochir, Tarletonbeania taylori, and Lampanyctus jordani), southern transition water (Symbolophorus californiensis, Diaphus theta, and Nannobrachium regale), and Kuroshio (Myctophum asperum and Diaphus garmani). The Subarctic Boundary defined the distributions of the northern and southern transition-water groups. The importance of areas of western North Pacific transition water as spawning and nursery grounds for subarctic, transitional, and subtropical myctophid fishes was indicated by the relationship between the horizontal distribution patterns of larvae, juveniles, and adults and the physical oceanographic structures.Communicated by T. Ikeda, Hakodate     

Heritability of the algal-foraging ability: an indirect benefit of female mate preference for males' carotenoid-based coloration in the guppy, Poecilia reticulata

Several sexual selection theories assume certain benefits of female mate preference. The direct benefit, i.e., the direct contribution from males to their offspring and females, has been well tested empirically. However, the indirect benefit, i.e., the male's genetic contribution to their offspring, has been poorly demonstrated. Female preference for males' carotenoid-based coloration is known in some animals. Since animals must acquire carotenoids through foods, it is often hypothesized that the brightness of the carotenoid-based coloration is a reliable indicator of the male's foraging ability. Hence, females' indirect benefits, such as greater foraging ability in their offspring, through mate preference for the carotenoid-based coloration are assumed. However, the heritability of the foraging ability for foods that serve as carotenoid resources has not been tested. In this study, a maze experiment was performed in guppies (Poecilia reticulata) to examine the heritability of the foraging ability for algae, carotenoid resources in nature. The latency for completing algal-foraging tasks in this experiment showed high individual variation. Heritable estimates of the foraging ability were substantial (h ² = 0.57 – 0.66) and significant, suggesting a genetic contribution to the foraging ability from fathers to their offspring. This result may support the hypothesis that indirect benefits influence the evolution of female choice.     

Effect of unburned carbon on lead, zinc, and copper recovery from molten fly ash by chloride-induced volatilization

The present work focuses on investigation of the effective recovery of heavy metals from molten fly ash by applying chloride-induced volatilization. In particular, the effect of unburned carbon on the chloride-induced volatilization of lead, zinc, and copper from model and real molten fly ashes was investigated in the temperature range 873–1173 K under a N₂ atmosphere. As a result, almost 100% of lead and a significant proportion of zinc were volatilized from the real molten fly ash samples at 1173 K. In contrast, for the model fly ash, volatilization ratios of lead and zinc at 1173 K were only 85% and 25%, respectively. Further, the results of X-ray diffraction analysis suggested that PbO in molten fly ash was converted either to Pb₂OCl₂ or Pb by respective chlorination and reduction reactions. Meanwhile ZnO and CuO in the molten fly ash were reduced to Zn and Cu by reaction with unburned carbon. Subsequently, Pb, Zn, and Pb₂OCl₂ were volatilized, but Cu remained in the solid residue. Finally, the volatilization ratio of zinc increased with the addition of carbon, and more than 98% of zinc was volatilized at 1173 K from a fly ash with a carbon content of 20%.     

增强企业内安全培训能力对策研究

依据中日合作项目《加强中国安全生产科学技术能力计划》成果,对比分析了中日对企业安全培训相关法规要求,明确了各自的优点、缺点,提出通过开展企业内安全培训负责人培训可增强企业内安全培训能力,并在宁波进行了试点。提出应当重视企业内安全培训工作,对生产经营单位安全培训规定进行修改,制定配套实施细则和办法,开展企业内安全培训负责人培训、把班组长培训制度化、充分利用外部培训机构等增强企业内安全培训能力的对策和建议。     

Coadaptive changes in physiological and biophysical traits related to thermal stress in web spiders

Web spiders are considered to have expanded their habitats from dim to bright environments during the evolutionary history. Because they are sedentary predators exposed to the sun, they may have developed a suite of adaptive traits to cope with thermal stress. We examined the critical thermal maximum, spectral reflectance of solar energy by the body surface, and surface–volume ratio (SVR) for 11 spider species. Analysis of the four genera having a pair of species inhabiting both bright and dim environments showed that species in bright environments exhibited higher lethal temperatures, but spectral reflectance and SVR did not differ. Independent contrasts using the 11 species indicated that critical thermal maximum was positively correlated with spectral reflectance and spectral reflectance was negatively correlated with SVR. These results suggest that physiological tolerance to high temperatures and a biophysical mechanism to reduce heat gain evolved jointly during the history of habitat expansion in araneoid spiders.     

Evaluation of current material stock and future demolition waste for urban residential buildings in Jakarta and Bandung,Indonesia: embodied energy and CO<Subscript>2</Subscript> emission analysis

First, this paper evaluates the current building material stock and future demolition waste for urban residential buildings in the cities of Jakarta and Bandung using a material-flow analysis. The actual on-site building measurements were conducted in Jakarta (2012) and Bandung (2011), focusing particularly on unplanned houses, to obtain building material inventory data. A total of 297 houses were investigated in Jakarta, whereas 247 houses were measured in Bandung. Second, this paper analyses the embodied energy and CO₂ emissions of building materials through an input–output analysis. The results show that, overall, the total material input intensity for the houses is 2.67 ton/m² in Jakarta and 2.54 ton/m² in Bandung. Two scenarios with zero and maximum reuse/recycling rates were designed to predict future demolition waste and the embodied energy/CO₂ emissions of building materials in Jakarta. Closed- and open-loop material flows were applied. If the maximum reuse/recycling rates are applied to the closed- and open-loop material flows in Jakarta, then it would become possible to not only decrease the final disposal waste (from 123.9 to 2.1 million ton) but also reduce the corresponding embodied energy (from 247.8 to 192.1 PJ) and CO₂ emissions (from 24.3 to 19.2 million ton CO₂-eq) compared with the zero reuse/recycling scenario from 2012 to 2020.