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1.
Kazunori Yamada Tetsuya Tamura Yuya Azaki Ayumi Kashiwada Yoji Hata Katsuya Higashida Yukihiro Nakamura 《Journal of Polymers and the Environment》2009,17(2):95-102
In this study, melB tyrosinase was applied for enzymatic removal of linear and branched p-alkylphenols from aqueous solutions. First, systematic studies were carried out to estimate the effects of the process parameters such as the temperature, pH value, and enzyme dose on quinone conversion of p-cresol as a model phenol compound. A variety of p-alkylphenols were removed from aqueous solutions through the tyrosinase-catalyzed quinone conversion and subsequent nonenzymatic adsorption of quinone derivatives on chitosan beads at pH 6.0 and 30 °C under the optimum conditions determined for p-cresol. The % removal values of 98–100 were obtained for p-n-alkylphenols. Branched p-alkylphenols with a weak estrogenic activity containing 4-tert-butylphenol and 4-tert-pentylphenol, which underwent no quinone conversion by commercially available mushroom tyrosinase in the absence of H2O2, were also effectively removed by further increasing either the melB tyrosinase concentration or the amount of added chitosan beads. The present technique is much effective in the fact that a series of reactions rapidly progress under mild conditions and the chitosan beads can be readily separated from the reaction medium after the enzymatic treatment. 相似文献
2.
Towards institutional analysis of sustainability science: a quantitative examination of the patterns of research collaboration 总被引:2,自引:2,他引:0
This paper examines quantitatively the patterns of collaboration over geographical boundaries in the emerging field of sustainability
science by empirically analyzing the bibliometric data of scientific articles. The results indicate that an increasing number
of countries are engaged in research on sustainability, with the proportion of articles published through international collaboration
rising as well. The number of countries engaged in international collaboration on sustainability research has been increasing,
and the diversity of countries engaged in research collaboration beyond national borders is also increasing. The geographical
patterns of collaboration on sustainability show that research collaboration tends to be conducted between countries which
are geographically located closely, suggesting that communication and information exchange might be limited within the regional
clusters. The focused fields of research activities on sustainability are significantly different between countries, as each
country has its focused fields of research related to sustainability. The specialization of research activities is also observed
in international collaboration. While these patterns of international collaboration within regional clusters focusing on specific
fields could be effective in promoting the creation, transmission, and sharing of knowledge on sustainability utilizing the
already existing regional networks, they could pose a serious obstacle to collecting, exchanging, and integrating diverse
types of knowledge, especially when it is necessary to deal with problems involving large-scale complex interactions with
long-term implications, such as climate change. It would be of critical importance to establish inter-regional linkages by
devising appropriate institutional arrangements for global research collaboration on sustainability science. 相似文献
3.
Iwahana Yuki Ohbuchi Atsushi Koike Yuya Kitano Masaru Nakamura Toshihiro 《Journal of Material Cycles and Waste Management》2017,19(1):226-234
Journal of Material Cycles and Waste Management - The radioactive nuclides in the incinerator fly ashes from municipal solid waste sampled in June 2006 were analyzed with γ-ray spectrometry.... 相似文献
4.
Yuya Takuwa Tadao Matsumoto Kazuyuki Oshita Masaki Takaoka Shinsuke Morisawa Nobuo Takeda 《Journal of Material Cycles and Waste Management》2009,11(4):305-311
Because landfill gas (LFG) contains an abundance of methane, the utilization of LFG as a renewable energy source is becoming
popular in many countries. LFG, however, contains various trace constituents, some of which may pose problems during utilization.
For example, siloxanes and halogenated volatile organic compounds (VOCs) can cause difficulties when present in the fuel of
gas engines. In addition, many VOCs and mercury have harmful effects on human health, especially on the health of workers
at landfill sites and people living near the landfills. Energy recovery from LFG is expected to make great progress in the
near future, particularly in Asia, but we found little information on the trace constituents of LFG in this region. Therefore,
we sought to characterize the trace components in LFG generated in two landfill sites in China and one site in Japan, to determine
the typical concentrations of these trace components in LFG, and to compare their concentrations among landfill sites in Asia.
We concluded that the trace components in LFG at the sites studied were mainly siloxanes generated from sewage sludge and
harmful benzene, toluene, ethylbenzene, and xylene compounds from petroleum products. 相似文献
5.
The bumblebee Bombus terrestris is not only an effective pollinator, but also a potential invasive alien species outside its native range. Recently, nearly
30% of queens of the Japanese native species Bombus hypocrita sapporoensis and B. hypocrita hypocrita were estimated to copulate with B. terrestris males in the field, suggesting that indigenous bumblebees could be genetically deteriorated through hybrid production with
the introduced species. In this study, we evaluated hybrid production between the introduced B. terrestris and the indigenous B. hypocrita sapporoensis under laboratory conditions. The hatching rate of eggs derived from interspecific matings was 0% and 8.6% depending on the
direction of the cross, which was significantly lower than that from intraspecific matings of B. terrestris (76.9%) and B. hypocrita sapporoensis (78.9%). Genetic studies using microsatellite markers revealed that both haploid and diploid individuals were present in
the egg stage, whereas all hatched larvae were haploid. In addition, histological studies revealed that eggs derived from
interspecific matings terminated development 2 days after oviposition. These results strongly suggested that eggs derived
from interspecific matings are inviable due to post-mating isolation mechanisms. Mass release of exotic pollinators could
cause serious population declines of native bumblebee species. 相似文献
6.
A simple system to evaluate the 222Rn (radon) exhalation rate from soil has been improved. A sampling cuvette of 2.1 L is placed so that it covers the targeted ground soil, and radon emanating from the soil accumulates within the cuvette for 24 h. Its internal radon concentration is measured by the combination of an activated charcoal (PICO-RAD) and a liquid scintillation counting system. This study shows variations of the conversion factor (CF: unit Bq m(-3)/cpm) of PICO-RAD. The range of CF due to temperature (10-30 degrees C) was between -21% and +69%, and this due to humidity (30-90%) was between 0% and -15%. Humidity and radon concentration in the cuvette covering soil tended to saturate in a few hours. The above information was used to correct the CF for the evaluation. The improved system shows high reliability and can be easily applied to natural environments. 相似文献
7.
Ichiro Naruse Ryo Yoshiie Tsutomu Kameshima Tsuyoshi Takuwa 《Journal of Material Cycles and Waste Management》2010,12(2):154-160
Homogeneous oxidation reactions of gaseous elemental mercury were experimentally tested to study the behavior of mercury compounds
that contribute to toxic emissions in combustion flue gas. Chemical equilibrium calculations and reaction kinetics analysis
were also carried out to help explain the experimental results. In particular, the chemical forms of oxidized mercury and
their reaction paths were verified in detail. Among the experimental results, molecular chlorine was confirmed to have a higher
oxidizing ability toward elemental mercury than hydrogen chloride does. From the chemical equilibrium calculation, the final
product of mercury compounds oxidized by chlorine was confirmed to be mercury chloride (HgCl2). Numerical analyses of reaction kinetics were mostly consistent with the experimental results and the chemical equilibrium
calculations. The ratio of mercury oxidization by chlorine increases with temperature from 473 K to 873 K, although it decreases
at temperatures higher than 1000 K. Sensitivity analysis revealed the dominant reaction path of the mercury oxidation by chlorine.
First, elemental mercury reacts with Cl radicals to form HgCl. Then, the HgCl reacts with Cl2 to produce HgCl2. 相似文献
8.
Virgin female cabbage butterflies, Pieris rapae crucivora, accept and mate with courting males, whereas mated females reject them and assume the “mate refusal posture”. This study
tested whether the biogenic amines, serotonin (5HT), dopamine (DA), and octopamine (OA), were responsible for this change
in behavior. The results showed that 2–3-day-old virgin females fed with 5HT rejected courting males significantly more frequently
compared with controls fed on sucrose. In contrast, the proportions of courting males rejected by virgin females fed with
either DA or OA did not differ from sucrose-fed controls. Oral application of each amine resulted in significantly increased
levels of the amine applied (or its metabolite) in the brain. The results strongly suggest that 5HT or a 5HT metabolite may
be responsible for the post-mating change in behavioral response of 2–3-day-old virgin females to courting males. Similar
effects of 5HT treatment were observed in 6–8-day-old virgin females, but in this case the results were only marginally different
from the controls, suggesting that the effect may decline with increasing female age. 相似文献
9.
Sustainability science is a rapidly expanding field, particularly given the current ecological crises facing many parts of the globe today. To generate a snapshot of the state of sustainability science, we analyzed the current status of sustainability research using citation and text analysis. By reflecting social needs on sustainability science and the increasing number of publications in this field, the landscape is expected to change during the last decade. Our results indicate that previously separated research clusters investigating discipline-focused issues are becoming integrated into those studying coupled systems. We also found the existence of hub clusters bridging different clusters like socio-ecological systems and transition management. We also observed a variety of other emerging research clusters, especially in energy issues, technologies, and systems. Overall, our analysis suggests that sustainability science is a rapidly expanding and diversifying field, which has affected many disparate scientific disciplines and has the potential to feed scientific understanding on socio-ecological systems and to drive society toward transition for sustainability. 相似文献
10.
Hiroko Nakamura Shingo Ii Hidenori Chida Ken Friedl Shinji Suzuki Junichiro Mori Yuya Kajikawa 《Sustainability Science》2014,9(2):193-204
Awareness is needed of sustainability issues that are currently neglected but potentially important. A computer-based approach can highlight unconscious and neglected areas because it can structure vast amounts of knowledge. In this article, we propose a methodology to perceive unconscious areas of sustainability with the support of a computer-based approach, which creates a matrix, named the recognized-unrecognized matrix, which highlights both local and globally neglected problems. A case study is conducted to consider the potential contribution of the aviation industry to sustainability issues. We demonstrate that a citation network analysis is an effective methodology to chart the recognized-unrecognized matrix. We highlight issues of water use in the aviation industry by designing an innovative water and air circulation system, which significantly reduces water and fuel consumption on board airplane flights. We also suggest a new approach to integrating both explicit and tacit knowledge to enable knowledge creation. 相似文献