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151.
Marco Antonio Leonel Caetano Douglas Francisco Marcolino Gherardi Takashi Yoneyama 《Ecological modelling》2008
In recent years, the world has witnessed an ever-growing concern towards global warming caused by greenhouse gases, such as carbon dioxide (CO2). In order to reduce the emissions of CO2 without limiting economic growth, substantial investments should target the development of clean technology and the expansion of forested areas. Considering the limited availability of resources, investments must be used in the most effective way. The present work proposes a method to efficiently manage these resources by applying the optimal control theory to a new mathematical model that describes the dynamics of the atmospheric CO2. The contributions of this work are twofold: (1) present a model that describes the dynamic relation of CO2 emission with investment in reforestation and clean technology and (2) present a method to efficiently manage the available resources by casting an optimal control problem. The mathematical model uses ordinary differential equations to relate the production of CO2 with forest area and Gross Domestic Product (GDP). The model parameters are adjusted to fit the actual published data. Given an appropriate performance index, the optimal solution is found by numerically solving the Two-Point Boundary Value Problem (TPBVP) that arises from the application of Pontriagyn's Maximum Principle. The sensitivity of the obtained numerical solution is evaluated with respect to the uncertainties in the model parameters. The main objective of this work is to provide a quantitative tool for the efficient allocation of resources to reduce the greenhouse effect caused CO2 emissions. 相似文献
152.
Mahmoud Elafify Maha Al-Ashmawy Mohammed Elsherbini Amera Abd El Latif Takashi Okanda 《Journal of environmental science and health. Part. B》2020,55(3):265-272
AbstractFood contaminated with Shiga toxin-producing Escherichia coli (STEC) represents a hazardous public health problem worldwide. Therefore, the present study was performed to elucidate the virulent and antimicrobial resistance characteristics of STEC isolated from milk and dairy products marketed in Egypt. A total of 125 samples (raw market milk, bulk tank milk, Kareish cheese, white soft cheese, and small scale-produced ice cream, 25 each) were collected for determination the prevalence and antimicrobial resistance profiling of STEC. Thirty-six STEC isolates were recovered from milk and dairy products. Serological analysis illustrated that three isolates were E. coli O157:H7 and 33 isolates belonged to different serotypes. Molecular examination indicated that all isolates harboured stx1 and/or stx2 genes, 14 isolates expressed eaeA gene and 3 isolates possessed rfbE gene. Antimicrobial resistance profiling of the isolates was both phenotypically and genetically examined. Interestingly, 31 out of 36 (86.11%) isolates were multidrug-resistant and harboured the extended-spectrum β-lactamase encoding genes, namely, blaCTX-M-15, blaSHV-12 and blaCTX-M-14. Moreover, 12 isolates (33.33%) harboured plasmid-mediated quinolone resistant gene, qnrS. The overall conclusion of the current investigation indicated insufficient hygienic measures adopted during milking, handling, and processing leading to development of pathogenic and multidrug-resistant STEC. 相似文献
153.
Major earthquakes cause widespread environmental and socioeconomic disruptions that persist for decades. Extensive ground disturbances that occurred during the shallow-focus Kumamoto earthquakes will affect future sustainability of ecosystem services west of Aso volcano. Numbers of earthquake-initiated landslides per unit area were higher in grasslands than forests, likely owing to greater root reinforcement of trees, and mostly initiated on ridgelines and/or convex/planar hillslopes. Most landslides traveled short distances and did not initially evolve into debris flows; resultant sediments and wood accumulating in headwater channels can be mobilized into debris flows during future storms. Fissures along ridgelines may promote water ingress and induce future landslides and debris flows that affect residents downstream. Native grasses are at risk because of habitat fragmentation caused by ground disturbances, extensive damage to rural roads, and abandonment of traditional pasture management practices. Sustainable management of affected areas needs to consider future risk of cascading hazards and long-term socioeconomic impacts. 相似文献
154.
Takashi Yamamoto Akiko Kida Yukio Noma Atsushi Terazono Shin-ichi Sakai 《Journal of Material Cycles and Waste Management》2018,20(1):214-222
Appropriate treatment of asbestos waste is a significant problem. In Japan, inertization of asbestos-containing waste by novel techniques approved by the Ministry of the Environment is now promoted. A quantitative method of testing with high sensitivity to the asbestos levels present in the inertization products is required for the approval process, but many testing methods are only qualitative. Thus, we have developed an evaluation method for asbestos in inertized products, consisting of the extraction of fibers from inertized products and determination of fiber number concentration by transmission electron microscopy. We adopted this testing method to evaluate thermally treated asbestos. It was found that fiber number concentrations of thermally treated asbestos decreased with increased treatment temperature, and were below the environmental level (102 Mf/g) at more than 1000 °C for chrysotile and crocidolite and more than 1400 °C for amosite and other amphibole forms of asbestos. 相似文献
155.
Ribeiro Bruno Yamashiro Yuta Goto Katsuaki Tomiyama Jun Yamamoto Takashi Yamashiki Yosuke 《Journal of Material Cycles and Waste Management》2023,25(4):2381-2389
Journal of Material Cycles and Waste Management - Shotcrete is a sprayed concrete placed on steep slopes that have been widely used because it can prevent surface weathering and erosion, and in... 相似文献
156.
Kubota R Kunito T Agusa T Fujihara J Monirith I Iwata H Subramanian A Tana TS Tanabe S 《Journal of environmental monitoring : JEM》2006,8(2):293-299
Arsenic concentrations in hair and urine, and urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, were examined for inhabitants of the Mekong Basin in Kratie Province, Cambodia. Also, the arsenic levels of tube-well water were determined. Total arsenic concentrations in tube-well water ranged from <1 to 886 microg L(-1), and 44.8% of these exceeded the WHO drinking water guideline of 10 microg L(-1). Elevated levels of arsenic were observed in the human hair and urine, and also a significant positive correlation was observed between the concentrations in hair and urine. These results suggest that the inhabitants are chronically exposed to arsenic through drinking the tube-well water. Levels of urinary 8-OHdG were higher for the subjects with higher arsenic levels in hair and urine, suggesting that induction of oxidative DNA damage was caused by chronic exposure to arsenic in tube-well water for the inhabitants in Kratie Province. To our knowledge, this is the first report on the oxidative DNA damage caused by chronic exposure to arsenic in groundwater for the inhabitants in Cambodia. 相似文献
157.
We studied the effect of calcite encrustation in stoneworts (Chara spp.) on P cycling in an aquatic ecosystem. Sequential fractionation was performed to quantify P fractions of the internodes of calcified (Ca-CF) and uncalcified (UCa-CF) Chara fibrosa Agardh ex Bruzelius. Our results showed that Ca-CF was able to store more P and about 14 to 23% of total P in Ca-CF was co-precipitated with encrusted calcite, while only 2 to 3% was found in UCa-CF. Furthermore, in Ca-CF, an increased amount of total P did not result in a higher release of bioavailable water-soluble and sodium hydroxide-extractable P. Extracellular calcification in Chara enhanced nutrient sink for P, provided a further bottom-up control of phytoplankton, and should be regarded as a positive feedback in stabilizing Chara dominance in lakes. 相似文献
158.
Determination of nitrous oxide, methane, and ammonia emissions from a swine waste composting process 总被引:7,自引:0,他引:7
Takashi Osada Kazutaka Kuroda Michihiro Yonaga 《Journal of Material Cycles and Waste Management》2000,2(1):51-56
The amounts of harmful gas emissions from the process of composting swine waste were determined using an experimental composting
apparatus. Forced aeration (19.2–96.1 l/m3/min) was carried out continuously, and exhaust gases were collected and analyzed periodically. With weekly turning and the
addition of a bulking agent in order to decrease the moisture content and increase air permeability, the temperature of most
of the contents rose to 70°C and composting was complete within 3–5 weeks. NH3, CH4, and N2O emissions were high in the early stage of composting. About 10%–25% of the nitrogen in the raw material was lost as NH3 gas during composting. The emission rate of NH3 mainly depended on the aeration rate, so that as the aeration rate rose, the level of NH3 emissions increased. The CH4 and N2O emissions could be kept lower with adequate treatment at more than 40 l/m3/min aeration. N2O may be mainly the result of the denitrification of NO
x
-N in the additional matured compost used as a composting accelerator.
Received: September 11, 1998 / Accepted: November 8, 1999 相似文献
159.
Tani T Arai R Nozoe S Tako Y Takahashi T Nakamura Y 《Journal of environmental radioactivity》2011,102(4):340-347
A dynamic compartment model was investigated to describe 14C accumulation in rice plants exposed to atmospheric 14C with temporally changing concentrations. In the model, rice plants were regarded to consist of three compartments: the ear and the mobile and immobile carbon pools of the shoot. Photosynthetically fixed carbon moves into the ear and the mobile carbon pool, and these two compartments release a part of this carbon into the atmosphere by respiration. Carbon accumulated in the mobile carbon pool is redistributed to the ear, while carbon transferred into the immobile carbon pool from the mobile one is accumulated there until harvest. The model was examined by cultivation experiments using the stable isotope, 13C, in which the ratios of carbon photosynthetically fixed at nine times during plant growth to the total carbon at the time of harvest were determined. The model estimates of the ratios were in relatively good agreement with the experimental observations, which implies that the newly developed compartment model is applicable to estimate properly the radiation dose to the neighboring population due to an accidental release of 14C from nuclear facilities. 相似文献
160.
Sustainable development is one of the most important ideas, and goals of our time. It is defined as "development which meets the needs and aspirations of the current generation and develops safe and sound society for future generation". Achieving sustainable development thus involves a vigorous and urgent debate on different dimensions. The different dimensions of sustainability as a framework involve all issues such as science, technology, economic growth and development, health, education, finance investment and trade, politics, natural disasters, population growth and terrorism, etc. No single dimension is responsible to develop sustainable society. This article mainly described the integrated relationship among the three dimensions ofsustainability. 相似文献