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91.
Films of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(propylene) (PP), PP/PHBV (4:1), blends were prepared by melt-pressing and investigated with respect to their microbial degradation in soil after 120 days. Biodegradation of the films was evaluated by Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction. The biodegradation and/or bioerosion of the PP/PHBV blend was attributed to microbiological attack, with major changes occurring at the interphases of the homopolymers. The PHBV film was more strongly biodegraded in soil, decomposing completely in 30 days, while PP film presented changes in amorphous and interface phase, which affected the morphology.  相似文献   
92.
Barred plumage is common among bird species. It is often interpreted as a form of crypsis because pigmentation patterns are less detectable against heterogeneous backgrounds. However, it has also been suggested that barred plumage could signal plumage condition, because it makes irregularities in the plumage perceptually salient. Little empirical work exists on the function of barred plumage, in part because we lack a way for quantifying the regularity of the pattern. Here, we present a method to analyze digital photographs of barred plumage and quantify the regularity of its pattern, and also provide software to perform the analysis. Using museum skins of five avian species, we tested under which conditions the method reliably captures differences among conspecific males in the regularity of their barred pattern. We found that measurements of regularity were highly repeatable when lighting conditions were standardized, unlike under variable illumination, and a relatively large area of barred plumage was analyzed, rather than small and non-representative subsections of plumage. The range of conditions under which the method performs well makes it adequate for use in the field, and we hope that it fosters research on the function of barred plumage as a communication signal.  相似文献   
93.
A methodology is presented to estimate the emissions of ships at berth based on their actual fuel consumption and the fuel quality. Accurate estimates of emissions from ships at berth demand reliable knowledge of the fuel consumption while at berth and associated fuel characteristics. However, assured information about energy use and fuel consumption of seagoing ships at berth is scarce. Proper estimation of ship emissions at berth is crucial for understanding the impact of shipping emissions on air quality and health in harbour cities as well as for a proper evaluation of the impact of abatement measures such as shore-side electricity and/or restrictions of sulphur content for shipping fuels to be used in ports. Therefore, a survey of energy consumption and fuel use on board of 89 seagoing ships was made in close cooperation with the Port of Rotterdam. Rotterdam is the major port of Europe ensuring that the results will have relevance for the larger European domain. On board of the ships at berth, a questionnaire was filled in by the chief engineer of that particular ship, assisted by two former mechanical shipping engineers employed at our organization. Survey results as well as the emission estimations are compared to the (scarce) information that is available and expert judgements in recent studies. The compiled survey data underlie the current Dutch emission estimation methodology for emissions of ships at berth.  相似文献   
94.
Genetic variation (mtDNA) of the European conger eel, Conger conger, was compared across five locations in the north-eastern Atlantic (Madeira, Azores, South Portugal, North Portugal and Ireland) and one location in the western Mediterranean (Mallorca). Genetic diversity of conger eel was high, and differentiation among regions was not significant. Additionally, comparisons of element:Ca ratios (Sr:Ca, Ba:Ca, Mn:Ca and Mg:Ca) in otolith cores (larval phase) and edges (3?months prior to capture) among the Azores, North Portugal, Madeira and Mallorca regions for 2?years indicated that variation among regions were greater for edges than cores. Therefore, while benthic conger may display residency at regional scales, recruitment may not necessarily be derived from local spawning and larval retention. Furthermore, data from otoliths suggest a separated replenishment source for western Mediterranean and NE Atlantic stocks. The combination of genetics and otolith chemistry suggests?a population model for conger eel involving a broad-scale dispersal of larvae, with limited connectivity for benthic juvenile life stages at large spatial scales, although the existence of one or multiple spawning grounds for the species remains uncertain.  相似文献   
95.
This study focuses on the investigation of the kinetics of municipal solid waste composting in three full-scale mechanical–biological treatment (MBT) plants. The aims were to test a kinetic model based on volatile solids (VS) content change for describing the composting process in MBT plants, and to identify the model parameters that affected the estimation of the reaction rate constant most. To achieve this, VS content and several environmental conditions, namely temperature, moisture content, oxygen concentration and total bulk density were monitored throughout the composting process. Experimental data was fitted with a first-order kinetic model, and a rate constant (k) characteristic of composting under optimum environmental conditions was obtained. The kinetic model satisfactorily described the experimental data for the three MBT plants. k values ranged from 0.043 ± 0.002 d?1 to 0.082 ± 0.011 d?1. Sensitivity analysis showed that the model parameters that most affected the estimation of k were the initial biodegradable volatile solids content, the maximum temperature for biodegradation and the optimum moisture content. In conclusion, we show for the first time that full-scale MBT plants can be successfully modelled with a composting kinetic model.  相似文献   
96.
Environmental Chemistry Letters - Herein, we describe a simple and inexpensive protocol for the hydrothiolation of alkynes. In this context, water extract of rice straw ash (WERSA) has been proven...  相似文献   
97.
Journal of Polymers and the Environment - This study was developed a novel nanostructured membrane by electrospinning process, from polyacrylonitrile (PAN) modify by hydroxypropyl methylcellulose...  相似文献   
98.
Environmental Science and Pollution Research - The control of pests in agricultural systems is currently based on the widespread use of pesticides that efficiently control pests but have negative...  相似文献   
99.
Environmental Science and Pollution Research - A new one-pot synthesis method optimized by a 23 experimental design was developed to prepare a biosorbent, sugarcane bagasse cellulose succinate...  相似文献   
100.
Ok G  Ji SH  Kim SJ  Kim YK  Park JH  Kim YS  Han YH 《Chemosphere》2002,46(9-10):1351-1357
The atmospheric contamination levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were evaluated from the analysis of pine needles in South Korea. Pine needles were collected from 30 sampling points at five main cities in South Korea (Busan, Daegu, Gwangju, Changwon and Jeju island). The highest concentrations of PCDDs/DFs (2.19–26.88 pg I-TEQ/g of dry weight) were measured at Busan, where is the city of the highest population density and traffic volume among five cities. The lowest concentration was detected at Jeju with 0.62 pg I-TEQ/g dry weight, suggesting Jeju could be an environmental background area in Korea. The dominant homologues of PCDDs/DFs in pine needles were the lower chlorine-substituted compounds such as tetra CDDs and CDFs, and the distribution ratios of PCDDs/DFs decreased with increase of the number of chlorine substituents. Homologue profiles of pine needle samples were similar to PCDDs/DFs profiles of the vapor phase in the ambient air, and thus the pine needles absorbed the vapor phase of PCDDs/DFs from air. Results suggested that pine needles could be used as an indicator of the atmospheric contamination for PCDDs/DFs in Korea.  相似文献   
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