Kinetic parameter estimation for decomposition of organic peroxides by means of DSC measurements

The thermal stability of organic peroxides (cumene hydroperoxide 80 wt% and dicumyl peroxide) was studied by means of calorimetric measurement (DSC, TA Q1000) in an isotherm mode and a dynamic mode. Analysis of power profiles released in the isothermal mode was combined with the analysis of the decomposed compounds by a gas chromatograph/mass spectrometer (GC/MS) to determine the reaction mechanisms corresponding to each of the two reactions. In this work, a methodology for estimating kinetic parameters was based on the comparison of the power profile (dynamic mode) given by the model to that obtained experimentally by changing the parameters values. Parameter estimation is achieved using the mixed estimation method where a genetic algorithm is combined with a locally convergent method.     

Plasticity in male courtship behaviour as a function of light intensity in guppies

The environment is profoundly important in shaping many aspects of animal phenotype, including courtship and mating behaviours. Courtship displays rely upon the transmission of visual information from the signaller to the receiver, which means they are likely to be less effective in visually poor conditions such as at low light or in turbid ecosystems. One might therefore predict that in visually poor environments it would be beneficial for individuals to plastically adjust their mating behaviour to maximise mating success. Here, we investigate the impact of the developmental and current visual environment (light intensity) upon male mating behaviour in the Trinidadian guppy Poecilia reticulata. Male guppies have two different mating tactics: They can court females with a visual sigmoid display or attempt to circumvent female choice by attempting a non-consensual copulation (gonapodium thrust). We reared juvenile guppies in low light and relatively high light intensities for 5 months before observing individual males for mating behaviour in both light conditions. We found that the current light environment is important in determining the frequency of both sigmoidal courtship displays and non-consensual copulation attempts. Males increase the frequency of sigmoidal displays at relatively high light and increase non-consensual mating attempts at low light, suggesting that males compensate for poor visual conditions via an adjustment in tactics. We also find a significant correlation in courtship effort between the different light environments, suggesting that there is individual consistency across time and context for this trait. Developmental environment was less important. However, we found that fish reared at lower light intensities continued to employ sigmoidal displays despite the poor current visual environment. Our data show that male mating behaviour is phenotypically plastic in response to recent light environment. This may have implications for understanding how animals cope with anthropogenic environmental change.     

Bats aloft: variability in echolocation call structure at high altitudes

Bats alter their echolocation in response to changes in ecological and behavioral conditions, but little is known about how they adjust call structure in response to changes in altitude. We examined altitudinal variation in the echolocation of Brazilian free-tailed bats, Tadarida brasiliensis, a species known to fly to altitudes of 3,000 m above the ground. From 50.2 h of recordings, we analyzed 113 high-quality echolocation call sequences recorded from 0 to 862 m above ground level. Bats flying near the ground used shorter, higher-frequency, broader-bandwidth calls compared to bats at higher altitudes, an effect likely due to the greater levels of echo-producing clutter (i.e., vegetation, buildings) found near the ground. When ground-level recordings are excluded, bats continue to shift towards the use of longer-duration, lower-frequency, narrower-bandwidth calls with increasing altitude. We propose that the observed high-altitude changes in call structure are a response to changing acoustic attenuation rates and/or decreasing insect densities at higher altitudes.     

Experimental study of recirculating flows generated by lateral shock waves in very large channels

Due to the lack of data on hydraulic-jump dynamics in very large channels, the present paper describes the main characteristics of the velocity field and turbulence in a large rectangular channel with a width of 4 m. Although a hydraulic jump is always treated as a wave that is transversal to the channel wall, in the case of this study it has a trapezoidal front shape, first starting from a point at the sidewalls and then developing downstream in an oblique manner, finally giving rise to a trapezoidal shape. The oblique wave front may be regarded as a lateral shockwave that arises from a perturbation at a certain point of the lateral wall and travels obliquely toward the centreline of the channel. The experimental work was carried out at the Coastal Engineering Laboratory of the Water Engineering and Chemistry Department of the Technical University of Bari (Italy). In addition to the hydraulic jump formation, a large recirculating flow zone starts to develop from the separating point of the lateral shock wave and a separate boundary layer occurs. Intensive measurements of the streamwise and spanwise flow velocity components along one-half width of the channel were taken using a bidimensional Acoustic Doppler Velocimeter (ADV). The water surface elevation was obtained by means of an ultrasonic profiler. Velocity vectors, transversal velocity profiles, turbulence intensities and Reynolds shear stresses were all investigated. The experimental results of the separated boundary layer were compared with numerical predictions and related work presented in literature and showed good agreement. The transversal velocity profiles indicated the presence of adverse pressure gradient zones and the law of the wall appears to govern the region around the separated boundary layer.     

Impacts of farmer field schools on productivity of vegetable farming in Indonesia

This study assesses the impact of farmer field schools (FFS) on the productivity of vegetable farming in vegetable‐producing areas of East Java and Bali, Indonesia. The FFS have equipped over 3,000 vegetable farmers with integrated crop management knowledge applicable to chilies and tomatoes. The FFS are expected to enhance farmers’ capacity such that they can increase production. This study employs a difference‐in‐differences (DiD) method to overcome selection bias. A survey of 250 FFS‐graduated farmers and 250 non‐FFS farmers were purposively randomly selected from the overall community of farmers. Focus group discussion was used to support the survey. The results indicate that FFS were successful for enhancing farmers’ capability in vegetable farming. Farmers who participated in FFS have higher productivity than those who did not. Farmers also could adapt and adopt the knowledge gained from FFS as they underwent a process of learning by doing. The impacts of the increase in farmers’ capacity can be more evident if weaknesses during the FFS preparation and implementation can be overcome, to ensure more participation, flexibility to fit different conditions/needs and continuous learning.     

Testis size variation in the greenfinch Carduelis chloris : relevance for some recent models of sexual selection

Interspecific evidence that testis size responds to selection caused by sperm competition has been obtained from many taxa. However, little is known about the sources of intraspecific variation in testis size, although such variation may have functional significance. Variation in testis size and asymmetry was studied within and between eight geographically separated (and genetically differentiated) populations of greenfinches Carduelis chloris. The relationships between testis size and plumage brightness (degree of yellowness) and the prevalence of haematozoan infections were also investigated in three of these populations, as they related to the predictions of the immunocompetence handicap hypothesis, and Møller's hypothesis relating directional testis asymmetry to phenotypic quality. There were large differences between populations in testis size, with males from northern populations having larger testes than those from southern populations. Within populations, large testes were associated with larger body size and greater age. When the influence of these factors was removed statistically, males with large testes were more likely to be infected with haematozoan parasites, and had brighter yellow plumage. No evidence was found that directional asymmetry in testis size was related to either of these measures of phenotypic quality. These results are consistent with the hypothesis that males with large testes, while signalling higher phenotypic quality as revealed by increased plumage brightness, also pay a cost in terms of reduced immunocompetence, revealed by the increased probability of infection in these males. That these patterns were similar in three different populations adds further strength to these conclusions. Our results suggest that studying the sources of variation in testis size among individuals can reveal interesting processes in sexual selection.     

Application of environmentally conscious manufacturing strategies for an automotive component

Application of appropriate environmentally conscious manufacturing strategies enables the sustainable development of products and processes. Automotive component manufacturers recognise the potential of applying appropriate strategies for attaining Triple Bottom Line benefits. In this context, three strategies such as eco-efficiency, waste minimisation and material efficiency are being applied to minimise environmental impacts associated with the manufacture of automotive products and its associated processes. A case study of an automotive component manufacturing firm has been exemplified. After conducting the study, the potential environmental impact was reduced by 20% and eco-efficiency was improved by 13%. Further, improvements have been observed in terms of overall resource consumption and material efficiency. The overall power consumption was reduced by 18% and weight of the component was reduced by 11%. The study aimed at improving the sustainable performance of product by incorporating green and environmentally friendlier manufacturing practices.

Abbreviations: USEPA: United Nations Environmental Protection Agency; OECD: Organisation for Economic Co-operation and Development; WBCSD: World Business Council for Sustainable Development; Eco-QFD: Environmental Quality Function Deployment; WCED: World Commission on Environment and Development; LCA: Life Cycle Assessment     

流域非点源水污染排放清单估算系统构建

基于流域水质改善与水环境管理需求,结合目前流域非点源水污染排放存在的问题,本研究采用SOA-B/S架构,运用MVC6和GIS与环境模型集成关键技术,构建流域非点源水污染排放清单估算系统,并系统梳理了地形数据、污染源环境统计数据、气象数据等基础信息,采用基于输出系数法的非点源水污染负荷估算模型,实现了对全年及年内各分水期非点源水污染排放清单的处理分析和估算。系统通过数据库、GIS平台、模型集成和业务系统建设,实现了对不同时间和空间尺度下不同地区的非点源水污染负荷估算,推进了流域非点源污染排放的信息化、科学化及可视化管理,为决策者制定流域水环境管理措施和方案提供了有力的技术支持。     

基于三维荧光光谱技术解析不同微生物法净化黑臭水体的效果

应用曝气、菌剂+曝气、生物促生剂+曝气、菌剂+生物促生剂+曝气4种微生物技术净化黑臭水体,分别考察了进水中溶解性有机物(DOM)的特征和来源及出水中DOM的特征和效果,采用三维荧光(EEM)光谱技术与平行因子(PARAFAC)模型相结合的方式对进出水DOM进行了分析。结果表明,不同处理方式下进出水DOM的不同组分荧光峰强度变化存在较明显的差异,经过菌剂和生物促生剂联合处理之后,对类腐殖质等难降解物质削减效果最好。FI、HIX和BIX指数分析表明各处理水样中的DOM整体处于较强的自生源特征。利用主成分分析法(PCA)对影响黑臭水体DOM的主要因素及其贡献量研究发现:第1主成分表现为陆源类腐殖质和生物源类腐殖质共存的现象,对水体中DOM的贡献率为54.98%;第2主成分反映了以微生物代谢过程为代表的内源污染,对水体中DOM的贡献率为26.56%。因此,利用三维荧光分析能够较好的反映水中DOM的去除情况,易于实时在线监测,对黑臭水治理具有重要意义。     

萨尔瓦多红树林管理问题中的补贴办法

本文概述了引起萨尔瓦多红树林退化的各种因素,并分析了拟议中的红树林产权变化对贫困的海岸带社区红树林的意义.目前萨尔瓦多红树林生态系统的采伐和转化模式可通过补贴权利的透镜来观察,这种补助就是为特定用途向一些参与者授予财产权(而不授权给别人).遗憾的是,对红树林资源的使用进行管理的现有法律法规体系是相互矛盾和含混不清的.一些现行的法律对生态系统的使用和转变问题做出了完全相反的规定.如果不对各项补贴权利重新定义,就不能确保对红树林进行合理、持续的管理.但这种权利的重新定义应考虑其生活与生态系统的健康状况密切相关的那些群体的需要.