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111.
The composition and structure of tree stands near the timberline have been studied on different slopes and at different elevations in the Tylaisko-Konzhakovsko-Serebryanskii Massif, the North Urals. It has been found that the upper limits of tree stands with different degrees of canopy closure have risen considerably (by about 100 m of elevation) since the mid-19th century, although the formation of these stands started as early as the late 18th century. Woodless areas in the eastern part of the massif started to be colonized by Larix sibirica in the late 18th to early 19th centuries; those in the western part, by Picea obovata in the mid-19th century; and in the southern part, by Betula tortuosa in the late 19th century. Analysis of meteorological data provides evidence for warming and increasing humidity of the climate since the late 19th century. Favorable climatic changes that facilitated the expansion of the forest have taken place both in the summer (prolongation of the growing period) and in winter seasons (increase of air temperature and precipitation). The observed differences in the composition and dynamics of tree stands between the studied areas of the mountain range are most probably explained by different requirements of tree species for the depth of snow cover and the degree of soil freezing.  相似文献   
112.
Life cycle assessment (LCA) is increasingly used in waste management to identify strategies that prevent or minimise negative impacts on ecosystems, human health or natural resources. However, the quality of the provided support to decision- and policy-makers is strongly dependent on a proper conduct of the LCA. How has LCA been applied until now? Are there any inconsistencies in the past practice? To answer these questions, we draw on a critical review of 222 published LCA studies of solid waste management systems. We analyse the past practice against the ISO standard requirements and the ILCD Handbook guidelines for each major step within the goal definition, scope definition, inventory analysis, impact assessment, and interpretation phases of the methodology. Results show that malpractices exist in several aspects of the LCA with large differences across studies. Examples are a frequent neglect of the goal definition, a frequent lack of transparency and precision in the definition of the scope of the study, e.g. an unclear delimitation of the system boundaries, a truncated impact coverage, difficulties in capturing influential local specificities such as representative waste compositions into the inventory, and a frequent lack of essential sensitivity and uncertainty analyses. Many of these aspects are important for the reliability of the results. For each of them, we therefore provide detailed recommendations to practitioners of waste management LCAs.  相似文献   
113.
114.
In situ remediation represents a series of challenges in interpreting the monitoring data on remedial progress. Among these challenges are problems in determining the progress of the remediation and the mechanisms responsible, so that the process can be optimized. The release of organic pollutants to groundwater systems and in situ remediation technologies alter the groundwater chemistry, but outside of natural attenuation studies using inorganic chemical analyses as indicators of intrinsic biodegradation, typically little attention has been paid to the changes in inorganic groundwater chemistry. Smith (2008) noted that during an electrical resistance heating remediation that took place at a confidential site in Chicago, a two‐orders‐of‐magnitude increase in chloride concentrations occurred during the remediation. This increase in chloride resulted in a corresponding increase in calcium as a result of what is known as the common ion effect. Carbon dioxide is the gas found in highest concentrations in natural groundwater (Stumm & Morgan, 1981), and its fugacity (partial pressure) corresponds directly with calcium concentrations. Carbon dioxide at supersaturation in groundwater is capable of dissolving organic compounds, such as trichloroethene, facilitating removal of nonaqueous‐phase liquids at temperatures below the boiling point of water. One means of diagnosing these reactions is through the use of compound‐specific isotopic analysis, which is capable of distinguishing between evaporation, biodegradation, and differences in sources. The appropriate diagnosis has the potential to optimize the benefits from these reactions, lower energy costs for removal of nonaqueous‐phase liquids, and direct treatment where it is needed most. © 2010 Wiley Periodicals, Inc.  相似文献   
115.
Human beings have engaged in animal husbandry and have slaughtered animals for food for thousands of years. During the majority of that time most societies had no animal welfare regulations that governed the care or slaughter of animals. Judaism is a notable exception in that from its earliest days it has included such rules. Among the Jewish dietary laws is a prohibition to consume meat from an animal that dies in any manner other than through the rigorously defined method of slaughter known as shechita. In recent decades more and more attempts have been initiated by governments around the world to either outright ban or to control and modify the practice of shechita. This paper presents the requisite background about shechita and then analyzes the ethics of some of the recent legislation. The analysis includes a rebuttal of the assertion that shechita is an inhumane method of slaughter. It further presents the consequences on the Jewish community of legislation to impose pre-slaughter stunning and explains why such legislation is unethical. The actual effect of labeling laws is discussed and it is shown why such laws are also un-ethical.  相似文献   
116.
Environmental Science and Pollution Research - Ionizing radiation (IR) is a form of high energy. It poses a serious threat to organisms, but radiotherapy is a key therapeutic strategy for various...  相似文献   
117.
Environmental Science and Pollution Research - The rapid economic development in China places a large demand for energy, and as a result, thermal power plants in China are producing an enormous...  相似文献   
118.
Environmental Science and Pollution Research - The pollution of heavy metals (HMs) in the soil has become one of the important factors affecting the national environment and human health....  相似文献   
119.
Bottom ash is the major by-product of municipal solid waste incineration(MSWI), and is often reused as an engineering material, such as road-base aggregate. However, some metals(especially aluminum) in bottom ash can react with water and generate gas that could cause expansion and failure of products containing the ash; these metals must be removed before the ash is utilized. The size distribution and the chemical speciation of metals in the bottom ash from two Chinese MSWI plants were examined in this study, and the recovery potential of metals from the ash was evaluated. The metal concentrations in these bottom ashes were lower than that generated in other developed countries. Specifically, the contents of Al,Fe, Cu and Zn were 18.9–29.2, 25.5–32.3, 0.7–1.0 and 1.6–2.5 g/kg, respectively. Moreover,44.9–57.0 wt.% of Al and 55.6–75.4 wt.% of Fe were distributed in bottom ash particles smaller than 5 mm. Similarly, 46.6–79.7 wt.% of Cu and 42.9–74.2 wt.% of Zn were concentrated in particles smaller than 3 mm. The Fe in the bottom ash mainly existed as hematite, and its chemical speciation was considered to limit the recovery efficiency of magnetic separation.  相似文献   
120.
Pyridine, an important chemical raw material, is widely used in industry, for example in textiles,leather, printing, dyeing, etc. In this research, a dielectric barrier discharge(DBD) system was developed to remove pyridine, as a representative type of nitrogen heterocyclic compound in drinking water. First, the influence of the active species inhibitors tertiary butanol alcohol(TBA),HCO_3~-, and CO_3~(2-)on the degradation rate of pyridine was investigated to verify the existence of active species produced by the strong ionization discharge in the system. The intermediate and final products generated in the degradation process of pyridine were confirmed and analyzed through a series of analytical techniques, including liquid chromatography–mass spectrometry(LC–MS), high performance liquid chromatography(HPLC), ion chromatography(IC), total organic carbon(TOC) analysis, ultraviolet(UV) spectroscopy, etc. The results showed that the degradation of pyridine was mainly due to the strong oxidizing power of ozone and hydroxyl radical produced by the DBD system. Several intermediate products including 3-hydroxyl pyridine, fumaric acid, 2, 3-dihydroxypyridine, and oxalic acid were detected. Nitrogen was removed from the pyridine molecule to form nitrate. Through analysis of the degradation mechanism of pyridine, the oxidation pathway was deduced. The study provided a theoretical and experimental basis for the application of DBD strong ionization discharge in treatment of nitrogen heterocyclic compounds in drinking water.  相似文献   
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