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941.
Using a hand dredge, a population of Cassidulus mitis Krau, 1954 was sampled monthly from February 1986 to January 1987 at 15 stations offshore from Vermelha Beach (22°5718 S; 43°948 W), in water depths ranging from 0 to 6 m. The sex ratio indicated a slight numerical dominance of females for adults and a larger numerical female dominance for juveniles. A von Bertalanffy growth curve was estimated as L=71.00 (1-e(-0.390t)), where L=length (mm) and t=time (yr). The instantaneous natural mortality rate (M) was estimated as 0.812. The population occupies a zone parallel to the beach, and displays a spatially aggregated pattern, with higher densities in areas characterized by coarse and very well sorted sand containing low amounts of organic matter.  相似文献   
942.
Interest in renewable energy sources has increased in recent years due to environmental concerns about global warming and air pollution,reduced costs and improved efficiency of technologies.Under the European Union(EU)energy directive,biomass is a suitable renewable source.The aim of this study was to experimentally quantify and characterize the emission of particulate matter(PM_(2.5))resulting from the combustion of two biomass fuels(chipped residual biomass from pine and eucalypt),in a pilot-scale bubbling fluidized bed(BFB)combustor under distinct operating conditions.The variables evaluated were the stoichiometry and,in the case of eucalypt,the leaching of the fuel.The CO and PM_(2.5)emission factors were lower when the stoichiometry used in the experiments was higher(0.33±0.1 g CO/kg and 16.8±1.0 mg PM_(2.5)/kg,dry gases).The treatment of the fuel by leaching before its combustion has shown to promote higher PM_(2.5)emissions(55.2±2.5 mg/kg,as burned).Organic and elemental carbon represented 3.1 to 30 wt.% of the particle mass,while carbonate(CO_3~(2-))accounted for between 2.3 and 8.5 wt.%.The particulate mass was mainly composed of inorganic matter(71% to 86% of the PM_(2.5)mass).Compared to residential stoves,BFB combustion generated very high mass fractions of inorganic elements.Chloride was the water soluble ion in higher concentration in the PM_(2.5)emitted by the combustion of eucalypt,while calcium was the dominant water soluble ion in the case of pine.  相似文献   
943.
Aljustrel mines were classified as having high environmental hazard due to their large tailings volume and high metal concentrations in waters and sediments.To assess acid mine drainage impacted systems whose environmental conditions change quickly,the use of biological indicators with short generation time such as diatoms is advantageous.This study combined geochemical and diatom data,whose results were highlighted in 3 groups:Group 1,with low p H(1.9–5.1)and high metal/metalloid(Al,As,Cd,Co,Cu,Fe,Mn,Ni,Pb,Zn;0.65–1032 mg/L)and SO_4(405–39124 mg/L)concentrations.An acidophilic species,Pinnularia aljustrelica,was perfectly adapted to the adverse conditions;in contrast,teratological forms of Eunotia exigua were found,showing that metal toxicity affected this species.The low availability of metals/metalloids in sediments of this group indicates that metals/metalloids of the exchangeable fractions had been solubilized,which in fact enables metal/metalloid diatom uptake and consequently the occurrence of teratologies;Group 2,with sites of near neutral p H(5.0–6.8)and intermediate metal/metalloid(0.002–6 mg/L)and SO_4(302–2179 mg/L)concentrations;this enabled the existence of typical species of uncontaminated streams(Brachysira neglectissima,Achnanthidium minutissimum);Group 3,with samples from unimpacted sites,showing low metal/metalloid(0–0.8 mg/L)and SO_4(10–315 mg/L)concentrations,high pH(7.0–8.4)and Cl contents(10–2119 mg/L)and the presence of brackish to marine species(Entomoneis paludosa).For similar conditions of acidity,differences in diversity,abundance and teratologies of diatoms can be explained by the levels of metals/metalloids.  相似文献   
944.
Thinning, as a forest management strategy, may contribute towards mitigating climate change, depending on its net effect on forest carbon (C) stocks. Although thinning provides off-site C storage (in the form of wood products) it is still not clear whether it results in an increase, a reduction or no change in on-site C storage. In this study we analyze the effect of thinning on C stocks in a long-term experiment. Different thinning intensities (moderate, heavy and unthinned) have been applied over the last 30 years in a Scots pine (Pinus sylvestris L.) stand, with a thinning rotation period of 10 years. The main C compartments were analyzed: above and belowground tree biomass, deadwood, forest floor and upper 30-cm of the mineral soil and tree biomass removed in thinning treatments. The results revealed that unthinned stands had the highest C stocks with 315 Mg C ha?1, moderate thinning presented 304 Mg C ha?1 and heavy thinning 296 Mg C ha?1, with significant differences between unthinned and heavily thinned stands. These differences were mainly due to C stock in live biomass, which decreased with thinning intensity. However, soil C stocks, forest floor and mineral soil, were not influenced by thinning, all of the stands displaying very similar values 102–107 Mg C ha?1 for total soil; 15–19 Mg C ha?1 for forest floor; 87–88 Mg C ha?1 for mineral soil). These results highlight the sustainability of thinning treatments in terms of C stocks in this pinewood afforestation, and provide valuable information for forest management aimed at mitigating climate change.  相似文献   
945.
This paper presents the outcome of a feasibility study on underground coal gasification (UCG) combined with direct carbon dioxide (CO2) capture and storage (CCS) at a selected site in Bulgaria with deep coal seams (>1,200 m). A series of state-of-the-art geological, geo-mechanical, hydrogeological and computational models supported by experimental tests and techno-economical assessments have been developed for the evaluation of UCG-CCS schemes. Research efforts have been focused on the development of site selection requirements for UCG-CCS, estimation of CO2 storage volumes, review of the practical engineering requirements for developing a commercial UCG-CCS storage site, consideration of drilling and completion issues, and assessments of economic feasibility and environmental impacts of the scheme. In addition, the risks of subsidence and groundwater contamination have been assessed in order to pave the way for a full-scale trial and commercial applications. The current research confirms that cleaner and cheaper energy with reduced emissions can be achieved and the economics are competitive in the future European energy market. However the current research has established that rigorous design and monitor schemes are essential for productivity and safety and the minimisation of the potential environmental impacts. A platform has been established serving to inform policy-makers and aiding strategies devised to alleviate local and global impacts on climate change, while ensuring that energy resources are optimally harnessed.  相似文献   
946.
The debate concerning occupational safety and health (OSH) interventions has recently focused on the need of improving the evaluation of interventions, and in particular on the need for providing information about why the intervention worked or not, under what circumstances and in which context. Key concepts in the analysis of the context are the drivers, i.e., those factors enabling, fostering or facilitating OSH interventions. However, the concept of driver for an OSH intervention is both confused and contested. Although the term is widely used, there is little consensus on how drivers should be understood, how important they are in different contexts and how they can facilitate interventions. This exploratory study based on interviews with the owner-managers and the safety officers of small and medium-sized enterprises (SMEs) gives an overview of the most characteristic drivers for OSH interventions. The results will be used to make an initial evaluation of SMEs' needs, and will help orient interventions and future research.  相似文献   
947.
The concept of resilience has become very popular, especially in the 21st century. This concept is applicable to many fields, from mechanics to a broad range of social sciences. Resilience has even become part of the national and global policies of the USA, the United Nations and the European Commission. The concept of resilience has also been implemented in the area of safety and health based on the criticism of the traditional approach to occupational safety and health, which does not result in a satisfactory level of occupational safety. The concept of resilience was adopted to research occupational safety and health in different fields and thus with different approaches, such as via socio-technical studies, the psychological and behavioral aspects of organizational resilience and the link with research on individual or family resilience and its influence on work.  相似文献   
948.
Purpose. The purpose of this particular study was to test a newly created instrument in describing the facilitators and barriers to occupational health and safety in small and medium-sized enterprises (SMEs) in Ontario, Canada. Methods. A cross-sectional design was used to identify the occupational health and safety culture of SMEs in public and private sectors in Ontario. Results. A total of 153 questionnaires were completed. The majority of respondents were female (84%) with a mean age of 49.8 years (SD 10.6). Seventy-four percent were supervisors. Seventy percent of respondents were from the private sector while 30% derived from the public sector including healthcare, community services, and non-profit organizations. Further, conducting regular external safety inspections of the workplace was found to be statistically associated with a safe work environment 2.88 95% CI [1.57, 5.27]. Conclusions. Strategies and training opportunities that focus on how to adapt occupational health and safety legislation to the nature and diversity of SMEs are recommended. Furthermore, employers may use such information to improve safety in their SMEs, while researchers can hopefully use such evidence to develop interventions that are applicable to meeting the occupational health and safety needs of SMEs.  相似文献   
949.
Objective: The objective of this study was to determine the prevalence of alcohol and illicit drug use among victims of fatal traffic accidents in the Metropolitan Region of Vitória, Brazil, during the period 2011–2012.

Methods: Blood samples were collected and analyzed for the presence of drugs from 391 deceased victims of traffic crashes that occurred in the Metropolitan Region of Vitória, Brazil. The victims included drivers, passengers, and pedestrians. Sociodemographic variables such as age, gender, day of the week, and period of the year in which the accidents occurred were recorded. The analyses were performed by a gas chromatography–flame ionization method for alcohol and by a gas chromatography–mass spectrometry for amphetamines, cocaine, and cannabis.

Results: The results showed that 44.8% (n = 175) of all cases were positive for alcohol and/or illicit drugs. The detection of alcohol and/or drugs was more frequent in young males, aged 17 to 34, whose samples were positive in 46.8% of cases. Small differences among drivers, passengers, and pedestrians were observed (drivers = 45.9%, passengers = 46.4%, and pedestrians = 45.6%). In general, the most prevalent drug was alcohol, with 141 positive cases (36.1%), followed by cocaine, with 47 positive cases (12%). Amphetamines and cannabis had positivity rates of 4.1 and 4.3%, with 16 and 17 positive cases, respectively. The combined use of alcohol and other drugs was found in 36 cases (9.2%). Crack cocaine use was observed in 27.7% of the positive cases for cocaine.

Conclusions: For the effective reduction of traffic accidents related to driving under influence of drugs (DUID), we suggest the intensification of enforcement actions against the use of alcohol by drivers, the definition of which illicit drugs should be surveyed, as well the cutoff values, the promotion of changing legislation to oblige drivers to provide samples for toxicological testing, and the establishment of public information programs and specific actions aimed at young drivers to promote behavioral changes.  相似文献   

950.
A decade ago, scholars such as Michael Woods suggested that mobilisation in response to development in rural spaces was the result of a redefinition of relations between individuals, communities and the State. This remains true with the rural representing a contested site characterised by debates concerning food and fibre, water and energy security. With the recent deployment of new energy technologies in areas traditionally used for agricultural production, increased confrontation and resistance over land use has forged unlikely alliances between farmers, environmentalists and concerned others, ultimately leading to the rise of a new form of rural citizenship. In the Australian state of New South Wales (NSW) where resistance to burgeoning coal seam gas operations has become the customary response of many rural communities, environmentalists and concerned others are mobilising in support of farmers, who self-identify as modern-day stewards and are actively working to protect a resource hierarchy of water, land and soil against industries believed to be putting these at risk. Adopting a qualitative case-study approach, this paper examines how residents and supporters in the regional Shire of Narrabri in NSW have responded to what many see as competing land uses. We argue that values traditionally associated with stewardship and rurality are being revalorised by citizens to actively oppose the visions of the State, which seek to prioritise extractive development over other alternate futures. We contend that this rise in rural relations represents a significant shift in the notion of citizens as “inhabitants” and presents a new and enduring form of agency.  相似文献   
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