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151.
在关于改善环境的科学与政策讨论中,最经常提到的话题之一就是如何使小型和中等规模的企业参与进来. 相似文献
152.
Alba Pineda-Solano Lina Saenz-Noval Subramanya Nayak Simon Waldram Maria Papadaki M. Sam Mannan 《Process Safety and Environmental Protection》2012,90(5):404-410
Alkylpyridine N-oxides are important intermediates in the pharmaceutical and agrochemicals industries. The N-oxides are produced via the homogeneously catalyzed oxidation of the respective alkylpyridines using a 50% excess of hydrogen peroxide. The competitive hydrogen peroxide decomposition produces oxygen in the flammable environment of alkylpyridines and thus forms a key hazard for this reaction. In this work, the N-oxidation was performed under pressure in the temperature range of 110–125 °C with different catalyst concentrations. It was shown that temperature had an undisputable positive effect on the N-oxidation efficiency. The accurate measurement of the pressure rise due to decomposition was difficult. However, only 5% of the added H2O2 decomposed when stoichiometric quantities were employed, even in the temperature of 110 °C. The N-oxidation was very efficient, even when the lowest concentration of catalyst employed in this study was used. 相似文献
153.
Shimabukuro VG Alexandre NM Coluci MZ Rosecrance JC Gallani MC 《International journal of occupational safety and ergonomics》2012,18(1):15-26
Physical therapists engage in work tasks that expose them to occupational risk factors related to musculoskeletal disorders. Due to the gap in the literature on instruments focused on those workers, this study adapted a job factors questionnaire to physical therapists, and assessed its psychometric properties. The questionnaire was adapted and its content validity was established. The psychometric properties were evaluated among 142 physical therapists. Reliability was verified using the temporal-stability design and internal consistency. Construct validity was assessed with the known-groups technique. Test-retest results demonstrated intraclass correlation coefficients between .82 and .90 (p < .001). Cronbach's α of .91 verified the reliability of the questionnaire. The known-groups technique demonstrated a statistically significant difference on the scores of the items when physical therapists were compared to office workers. The results indicated that the adapted questionnaire had acceptable psychometric properties for assessing problematic job factors among physical therapists working in hospitals. 相似文献
154.
María Pía Areal M. Lorena Arciniegas Fernanda Horst Verónica Lassalle Francisco H. Sánchez Vera A. Alvarez Jimena S. Gonzalez 《Journal of Polymers and the Environment》2018,26(8):3129-3138
Scientific and technological researches are devoted to obtain materials capable of retaining different kinds of pollutants, contributing to contamination solutions. In this context, hydrogels have emerged as great candidates because of their excellent absorption properties as well as good mechanical, thermal and chemical properties. More specifically, ferrogels (magnetic gels) present the extra advantage of being easily manipulated by a permanent magnet. Here, we present the results derived from the application of ferrogels as efficient tools to extract heavy metal pollutants from wastewater samples. The gels were prepared following the method of freezing and thawing of a polyvinyl alcohol aqueous solution with magnetic nanoparticles coated with polyacrylic acid. Ferrogels were fully characterized and their ability to retain Cu2+ and Cd2+, as model heavy metals, was studied. Thus kinetics and mechanisms of adsorption were evaluated and modeled. The concentration of MNPs on the PVA matrix was key to improve the adsorption capability (approximately the double of retention is improved by the MNPs addition). The adsorption kinetics was determined as pseudo-second order model, whereas the Langmuir model was the most appropriate to explain the behavior of the gels. Finally reuse ability was evaluated to determine the real potential of these materials, the ferrogels demonstrated high efficiency up to about five cycles, retaining about 80–90% of their initial adsorption capability. All the results indicated that the materials are promising candidates able to compete with the commercial technology regarding to water remediation. 相似文献
155.
Objective: The objectives of the present article were to (a) describe the main characteristics of bicycle crashes with regard to the road environment, crash opponent, cyclist, and crash dynamics; (b) compare individuals who describe their health after the crash as declined with those who describe their health as not affected; and (c) compare the number of injured cyclists who describe their health as declined after the crash with the predicted number of permanent medical impairments within the same population.Methods: A sample of individuals with specific injury diagnoses was drawn from the Swedish Traffic Accident Data Acquisition (STRADA) database (n?=?2,678). A survey form was used to collect additional information about the crash and the health-related outcomes. The predicted number of impaired individuals was calculated by accumulating the risk for all individuals to sustain at least a 1% permanent medical impairment, based on the injured body region and injury severity.Results: Nine hundred forty-seven individuals (36%) responded, of whom 44% reported declined health after the crash. The majority (68%) were injured in single bicycle crashes, 17% in collisions with motor vehicles, and 11% in collisions with another cyclist or pedestrian. Most single bicycle crashes related to loss of control (46%), mainly due to skidding on winter surface conditions (14%), followed by loss of control during braking (6%). There was no significant difference in crash distribution comparing all crashes with crashes among people with declined health. The predicted number of impaired individuals (n?=?427) corresponded well with the number of individuals self-reporting declined health (n?=?421).Conclusions: The types of crashes leading to health loss do not substantially differ from those that do not result in health loss. Two thirds of injuries leading to health loss occur in single bicycle crashes. In addition to separating cyclists from motorized traffic, other preventive strategies are needed. 相似文献
156.
Alberto Martinetti Maria Mikela Chatzimichailidou Luisa Maida Leo van Dongen 《International journal of occupational safety and ergonomics》2019,25(1):66-75
Occupational health and safety (OHS) represents an important field of exploration for the research community: in spite of the growth of technological innovations, the increasing complexity of systems involves critical issues in terms of degradation of the safety levels. In such a situation, new safety management approaches are now mandatory in order to face the safety implications of the current technological evolutions. Along these lines, performing risk-based analysis alone seems not to be enough anymore. The evaluation of robustness, antifragility and resilience of a socio-technical system is now indispensable in order to face unforeseen events. This article will briefly introduce the topics of Safety I and Safety II, resilience engineering and antifragility engineering, explaining correlations, overlapping aspects and synergies. Secondly, the article will discuss the applications of those paradigms to a real accident, highlighting how they can challenge, stimulate and inspire research for improving OHS conditions. 相似文献
157.
Verônica da Fonsêca-Genevois Paul J. Somerfield Maria Helena Baeta Neves Ricardo Coutinho Tom Moens 《Marine Biology》2006,148(5):1039-1050
An experiment was undertaken at Farol Island, Brazil, to examine colonization of bare aluminium surfaces by microbes and meiofauna.
It was hypothesized that a primary source of meiofaunal colonists was sediment resuspended during upwelling events, two of
which occurred during the experiment. Microbial biofilms formed on the experimental substrata within 1 day, and continued
to develop throughout the experimental period. Among meiofaunal groups copepods also appeared on the first day, and nematodes
on the second. Meiofaunal community structure developed in three main phases: an initial phase of 2 days, characterized by
low abundances of copepods; a second phase during the first upwelling period characterized by higher abundances of copepods
and also by turbellarians; and a third phase from day 13 onwards characterized by relatively stable abundances of a range
of taxa including copepods, cirripedes, nematodes and ostracods. Nematode assemblages also developed in three phases, but
with different timings coinciding with upwelling events: an initial phase, from the beginning of the experiment to day 9,
characterized by few species and low (or no) abundances; a second phase following the first upwelling characterized by moderate
abundances of Chromadorina, Chromadorella, Daptonema and Euchromadora sp. 3; a third phase following the second upwelling period (from day 26 onwards) in which Daptonema disappeared and the assemblage was characterized by moderate to high abundances of Euchromadora (species 1 and 2) and Chromadorella. Although shifts in nematode assemblage structure coincided with upwelling events no evidence was found for sediments being
the primary source of colonizers on the aluminium substrata, in contrast to our hypothesis. 相似文献
158.
This study evaluated the potential toxicological risk posed to human health due to the exposure to heavy metals by water ingestion
in an area affected by tanneries – the Cadeia-Feitoria hydrographic basin (Brazil). River water was collected at 10 sites,
every 3 months, from July 1999 to April 2000. After acid digestion, total metal concentration was determined by inductively
coupled plasma optical emission spectrometry (Cd, Cu, Cr, Ni, Zn), flame atomic absorption (Al, Fe, Pb, Mn), or cold vapor
atomic absorption spectrometry (Hg). Cr(VI) was complexed with diphenyl-carbazide and detected by UV–vis spectrometry. In
order to quantify the risk of exposure, the risk assessment methodology employed by the Environmental Protection Agency of
the United States was applied at a screening level. The assumed scenarios included extreme exposure patterns (ingestion of
untreated water, conversion of Cr(III) to Cr(VI), temporal peaks of pollution). Fe, Al, Cd, Hg, and Pb were not included in
the risk analysis, since they showed a low toxicity potential or were undetected in the samples. The selected metals presented
Hazard Quotients < 1, in the following order of increasing risk: Cu < Cr(III) < Zn < Ni < Mn < Cr(VI). Hazard indexes, representing
the additive effect of contaminants, were also low in the basin (< 1), but comparatively increased in the lower reach of Feitoria
and Cadeia Rivers. Although noncarcinogenic risk levels did not suggest possible adverse toxicological effects to the human
population, a considerable deviation from background conditions was observed downstream the area where tanneries are mainly
located. 相似文献
159.
Summary This study reports an aviary experiment aimed at determining what affects social dominance in the great tit (Parus major), especially why older birds (adults) in nature normally dominate younger ones (juveniles). When birds were matched with respect to age, prior residency determined dominance. Without a difference in prior residency older birds dominated younger ones. However, when juvenile birds had a prior residency advantage over adult birds, they often became dominant. This was especially so when the juvenile bird was large relative to the adult bird. When a resident juvenile male was also consorted by a female, he became dominant over an adult male on most occasions. An experiment where the dominant bird was removed and later returned to the aviary failed to produce more than one shift in dominance. However, the proportion of reversals in dominance interactions increased with separation time. It is argued that the fact that dominance depends on prior residency selects for winter residency in the great tit.Offprint requests to: H.G. Smith 相似文献
160.
Human digit ratios depend on birth order and sex of older siblings and predict maternal fecundity 总被引:1,自引:0,他引:1
In men, the length ratio of the second to fourth finger (2D:4D) is smaller, while the length of the fourth finger relative
to body height (4D:H) is larger than in women. Inter- and intrasexual variations in 2D:4D and 4D:H may depend on variation
in fetal androgen and oestrogen environment. As maternal physiology varies with parity and is differentially affected by gestation
of either sex, offspring 2D:4D and 4D:H may change according to sex and number of older siblings and may predict subsequent
maternal performance. We analysed 2D:4D and 4D:H in Caucasian university students. 2D:4D was smaller and 4D:H was larger in
males than in females, but no sexual dimorphism existed in 2D:H. In males, length ratios did not vary with birth order. 2D:4D
became more masculine with increasing proportion of males among older siblings, and 2D:4D and 4D:H became more feminine as
the number of older sisters increased. In females, length ratios did not vary with the number of older sisters or brothers.
2D:4D was also not related to birth order, but 4D:H became more masculine with birth order. In females, residual maternal
fecundity (number of maternal offspring after the participant) decreased as 4D:H became more masculine. These findings are
partly consistent with those from previous studies and suggest that maternal fecundity co-varies with length ratios and thus
possibly fetal hormone environment of older offspring. 2D:4D and 4D:H may therefore represent powerful tools to investigate
the relationships between fetal environment, offspring phenotype and maternal life history at mechanistic and evolutionary
levels. 相似文献