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731.
K. Rajakumar V. Sarasvathy A. Thamarai Chelvan R. Chitra C. T. Vijayakumar 《Journal of Polymers and the Environment》2009,17(3):191-202
Polypropylene (PP) has achieved a dominating position and hence, their consumption increases thereby littering, which lead
to environmental pollution. Photodegradation seems to be a better choice because of naturally available sunlight as energy
source for degradation. The present work involves the study of the variation of degradation behavior of PP film during tropical
summer and winter seasons. The photodegradation is followed by Fourier transform infrared (FTIR) spectroscopic technique.
Various indices like hydroxyl, carbonyl, vinylidene, lactones, ester, carboxylic acid and crystallinity are calculated and
these values increased after a brief induction period. The variation in the mechanical properties like tensile strength and
elongation at break percentages are determined. The scanning electron microscopic (SEM) images of weathered PP showed surface
cracks when carbonyl index value increases sharply and the mechanical properties show a sudden decrease. Attempted life time
prediction using mathematical models showed that the carbonyl growth is more affected by ultraviolet (UV) and cumulative total
solar radiation for PP weathered during summer. The loss in tensile strength of PP weathered during summer is more dependent
on the average temperature and the UV portion of the total solar radiation whereas, intensity of UV radiation has profound
effect on the tensile strength of PP weathered during winter. 相似文献
732.
Jehangir T. Madhani Joseph Young Neil A. Kelson Richard J. Brown 《Water, Air, & Soil Pollution: Focus》2009,9(5-6):357-369
A novel method is developed to capture and analyze several experimental flow regimes through a gross pollutant trap (GPT) with fully and partially blocked screens. Typical flow conditions and screen blockages are based on findings from field investigations that show a high content of organic matter in urban areas. Fluid motion of neutral buoyant particles is tracked using a high-speed camera and particle image velocimetry (PIV) software. The recorded fluid motion is visualized through an image-based, line integral convolution (LIC) algorithm, generally suitable for large computational fluid dynamics (CFD) datasets. The LIC method, a dense representation of streamlines, is found to be superior to the point-based flow visualization (e.g., hedgehog or arrow plots) in highlighting main flow features that are important for understanding litter capture and retention in the GPT. Detailed comparisons are made between the flow regimes, and the results are compared with CFD data previously obtained for fully blocked screens. The LIC technique is a useful tool for identifying flow structures in the GPT and areas that are subjected to abnormalities difficult to detect by conventional methods. The novel method is found to be useful both in the laboratory and in the field, with little preparation and cost. The enhancements and pitfalls of the LIC technique along with the experimentally captured flow field are presented and discussed. 相似文献
733.
Richard Roth Paul R. Marques Robert B. VoasAuthor vitae 《Journal of Safety Research》2009,40(6):437-441
Introduction
The effectiveness of ignition interlocks at reducing drunk driving has been limited by the ability of driving-while-intoxicated (DWI) offenders to avoid court orders to install the devices.Methods
In a pilot program in New Mexico, four Santa Fe County judges imposed home confinement (via electronic monitoring bracelets) on offenders who claimed to have no car or no intention to drive. Interlock installation rates for Santa Fe County were compared with all other counties in New Mexico over a 2-year program and 2-year post-program period.Results
During the two program years, 70% of the drivers convicted of DWI in Santa Fe County installed interlocks, compared to only 17% in the other counties, but when the program was terminated, the Santa Fe installation rate fell by 18.8 percentage points.Summary
Mandating the alternative sanction of house arrest led to the highest reported interlock installation rate for DWI offenders.Impact on Industry
Impaired driving is a substantial expense to employers, particularly when it bars driving that interferes with employment. Interlocks provide a method of protecting the public while permitting the offender to drive sober. This study was directed at increasing interlock use by DWI offenders. 相似文献734.
Sinkings of fishing vessels, when accompanied by human loss, are accidents which lead to a great social upheaval, especially in the local area where they occur. In order to avoid or reduce these accidents, national governments must include in their legislation for this sector the appropriate safety measures. These resources and their distribution must be assigned in accordance with the needs of the accidentality, this requiring a detailed knowledge of the concentration of accidentality of a country’s fishing sector. In this context, the aim of the present work is twofold: first, to formulate a methodology for the fishing sector of a country, allowing the inequalities in the concentration of sinking accidents to be analysed; and second, to apply this methodology to the Spanish fishing fleet. Thus, two indices are constructed per region and type of fishing, for two variables: fishermen and vessels. Results are obtained both for the concentration of accidents and the associated Lorenz curves. An increase in the inequality in the spatial and functional distribution of these accidents is verified. 相似文献
735.
Mario C.R. Vidal Paulo V.R. Carvalho Marcello S. Santos Isaac J.L. dos Santos 《Journal of Loss Prevention in the Process Industries》2009,22(4):516-527
This article aims to describe the characteristics of collective working situations in complex systems – especially those in nuclear power plants – related to common forms of cooperation, in order to improve systems resilience. In addition, we will try to detail some aspects of collective working situations, emphasizing the differences between various forms of control. The similarities between work activities (multi-addressed messages, linkage to regulation, central and peripheral information) are nonetheless exposed. We conclude by proposing a contribution to support systems design, thus facilitating cooperation in teamwork activities. 相似文献
736.
Past changes and possible future variations in the nature of extreme precipitation and flood events in Central Europe and
the Alpine region are examined from a physical standpoint. An overview is given of the following key contributory physical
processes: (1) the variability of the large-scale atmospheric flow and the associated changes of the North-Atlantic storm
track; (2) the feedback process between climate warming and the water cycle, and in particular the potential for more frequent
heavy precipitation events; and (3) the catchment-scale hydrological processes associated with variations in major river flooding
events and that are related to land-use changes, river training measures, and shifts in the proportion of rain to snowfall.
In this context an account is provided of the possible future forecasting and warning methodologies based upon high-resolution
weather prediction and runoff models. Also consideration is given to the detectability of past (future) changes in observed
(modeled) extreme events. It is shown that their rarity and natural fluctuation largely impedes a detection of systematic
variations. These effects restrict trend analysis of such events to return periods of below a few months. An illustration
using daily precipitation from the Swiss Alps does yield evidence for pronounced trends of intense precipitation events (return
period 30 days), while trends of stronger event classes are not detectable (but nevertheless can not be excluded). The small
detection probability for extreme events limits possible mitigation of future damage costs through an abatement of climate
change alone, and points to the desirability of developing improved early forecasting/warning systems as an additional no-regret
strategy.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
737.
Jean-Charles Hourcade Minh Ha-Duong Arnulf Grübler Richard S.J. Tol 《Integrated Assessment》2001,2(1):31-35
This communication summarizes the main findings of INASUD, an European-wide research project on integrated assessment of climate policies. The project aimed at improving the framing of climate policy analysis through the parallel use of various existing integrated assessment models. It provides a comprehensive examination of the link between uncertainty regarding damages and inertia in economic systems. Results show that the Kyoto targets and timing are consistent with the precautionary principle but offers little insurance for longer-term climate protection. Flexibility mechanisms offer potentials for cooperation with developing countries, and are necessary to tap the environmental and economic benefits of joint carbon and sulfur emissions abatement. 相似文献
738.
Fernandes C Fontaínhas-Fernandes A Cabral D Salgado MA 《Environmental monitoring and assessment》2008,136(1-3):267-275
Esmoriz–Paramos lagoon is an ecosystem of great ecological importance that is located on the northwest coast of Portugal and
has been degraded as a result of industrial and anthropogenic activities. Concentrations of heavy metals (Cr, Cu, Pb and Zn)
were measured in water, sediment and in tissues (liver and muscle) of Liza saliens, which is the dominant fish from the lagoon. Comparisons between metal concentrations in water and sediments were made with
those in tissues of fish caught at the lagoon. Metals in water were quantified predominantly bound to particulate and equalled
or exceeded the limit of chronic reference values. Metal concentrations in sediments varied among sampled sites. The relative
order of concentrations was “Zn > Cu ∼ Pb > Cr” the same pattern observed for metals in water. Metals in fish tissues showed
higher concentrations in liver (262 mg Cu·Kg−1 and 89 mg Zn·Kg−1) than in muscle (<3 mg Cu·Kg−1 and 26 mg Zn·Kg−1), while Pb and Cr were not detected. These results suggest that Cu and Zn are the metals of major concern in the lagoon.
Mullet detritivorous feeding habits, bioaccumulation pattern and the high sediment metals concentrations relative to the water
suggest that sediments can be the most important source of contamination in this ecosystem. The positive relationship found
between Cu in liver and fish length demonstrates that time of exposure is a crucial factor in bioaccumulation. Condition indices
(K and HSI) in mullets from the lagoon were higher compared to mullets from sea, suggesting abnormal condition in the lagoon
population. We conclude that metals chronic exposure in the lagoon can impose considerable fish stress. The results also show
that the lagoon is an area of environmental concern. 相似文献
739.
Schaefer CE do Amaral EF de Mendonça BA Oliveira H Lani JL Costa LM Fernandes Filho EI 《Environmental monitoring and assessment》2008,140(1-3):279-289
The relationships between soils attributes, soil carbon stocks and vegetation carbon stocks are poorly know in Amazonia, even
at regional scale. In this paper, we used the large and reliable soil database from Western Amazonia obtained from the RADAMBRASIL
project and recent estimates of vegetation biomass to investigate some environmental relationships, quantifying C stocks of
intact ecosystem in Western Amazonia. The results allowed separating the western Amazonia into 6 sectors, called pedo-zones:
Roraima, Rio Negro Basin, Tertiary Plateaux of the Amazon, Javari-Juruá-Purus lowland, Acre Basin and Rondonia uplands. The
highest C stock for the whole soil is observed in the Acre and in the Rio Negro sectors. In the former, this is due to the
high nutrient status and high clay activity, whereas in the latter, it is attributed to a downward carbon movement attributed
to widespread podzolization and arenization, forming spodic horizons. The youthful nature of shallow soils of the Javari-Juruá-Purus
lowlands, associated with high Al, results in a high phytomass C/soil C ratio. A similar trend was observed for the shallow
soils from the Roraima and Rondonia highlands. A consistent east–west decline in biomass carbon in the Rio Negro Basin sector
is associated with increasing rainfall and higher sand amounts. It is related to lesser C protection and greater C loss of
sandy soils, subjected to active chemical leaching and widespread podzolization. Also, these soils possess lower cation exchangeable
capacity and lower water retention capacity. Zones where deeply weathered Latosols dominate have a overall pattern of high
C sequestration, and greater than the shallower soils from the upper Amazon, west of Madeira and Negro rivers. This was attributed
to deeper incorporation of carbon in these clayey and highly pedo-bioturbated soils. The results highlight the urgent need
for refining soil data at an appropriate scale for C stocks calculations purposes in Amazonia. There is a risk of misinterpreting
C stocks in Amazonia when such great pedological variability is not taken into account. 相似文献
740.
Seasonal variations of heavy metal contamination in river Gomti of Lucknow city region 总被引:2,自引:0,他引:2
Lohani MB Singh A Rupainwar DC Dhar DN 《Environmental monitoring and assessment》2008,147(1-3):253-263
The present study deals with the seasonal variations in the concentrations of heavy metals namely chromium, lead and mercury by using spectrophotometric methods. The water samples were collected at regular intervals from five selected sites of river Gomti in the pre-monsoon period (months of February-May) and the post monsoon period (months of October-January). The concentrations of chromium (VI) and mercury (II) were determined by using Genesys-10 UV-VIS Spectrophotometer while lead (II) concentrations were determined using Atomic Absorption Spectrophotometer, Perkin-Elmer 5000 model. The concentrations of all the three metals were found to be higher in the pre-monsoon period than in the post-monsoon period. The statistical analysis of the data was discussed in both the seasons in terms of mean, standard deviation and coefficient of variation. 相似文献