Gasoline Evaporation–Ethanol and Nonethanol Blends

Tests were performed to compare the evaporation rate of 10 volume percent (vol%) ethanol-blended gasoline (E10) with the evaporation rate of its base gasoline. Weight loss, temperature, pressure, and humidity were monitored as lab-blended E10 and base gasolines were evaporated concurrently from glass cylinders placed on balances located side by side under an exhaust hood. The averaged results of four tests at about 70°F showed that the E10 lost more total weight to evaporation than the base fuel, but less gasoline. The increased weight was due to ethanol, which was present in the E10 evaporative emissions at concentrations of about 13 weight percent (wt%). In two-hour tests at temperatures near 70°F, during which 4.5 to 5.3 wt% of initial fuel samples were evaporated, E10 fuels lost an average of about 5% less gasoline than their base fuels. A similar result was obtained for a one-hour test, during which about 2.4 to 2.5 wt% of the initial fuel samples were evaporated. Gas chromatography (GC) component analysis indicated that the compositions of the ethanol-free emissions from the two fuels were similar. Reid vapor pressure (RVP) measurements made using a Grabner CCA-VPS according to ASTM D5191-91 indicated that E10 fuels underwent an approximate 5% greater RVP reduction than their respective base fuels.     

Ag/Ag2SO3 plasmonic catalysts with high activity and stability for CO2 reduction with water vapor under visible light

Environmental Science and Pollution Research - The conversion of CO2 into useful raw materials for fuels and chemicals by solar energy is described using a plasmonic photocatalyst comprised of Ag...     

Binding characteristics of Cu2+ to natural humic acid fractions sequentially extracted from the lake sediments

Humic acids (HAs) determine the distribution, toxicity, bioavailability, and ultimate fate of heavy metals in the environment. In this work, ten HA fractions (F1–F10) were used as adsorbent, which were sequentially extracted from natural sediments of Lake Wuliangsuhai, to investigate the binding characteristics of Cu²⁺ to HA. On the basis of the characterization results, differences were found between the ten extracted HA fractions responding to their elemental compositions and acidic functional groups. The characterization results reveal that the responses of ten extracted HA fractions to their elemental compositions and acidic functional groups were different. The O/C and (O + N)/C ratio of F1–F8 approximately ranged from 0.66 to 0.53 and from 0.72 to 0.61, respectively; the measured results showed that the contents of phenolic groups and carboxyl groups decreased from 4.46 to 2.60 mmol/g and 1.60 to 0.58 mmol/g, respectively. The binding characteristics of Cu²⁺ to the ten HA fractions were well modeled by the bi-Langmuir model; the binding behavior of Cu²⁺ to all the ten HA fractions were strongly impacted by pH and ionic strength. The FTIR and SEM-EDX image of HA fractions (pre- and post-adsorption) revealed that carboxyl and phenolic groups were responsible for the Cu²⁺ sorption on the ten sequentially extracted HA fractions process, which is the same with the analysis of the ligand binding and bi-Langmuir models Accordingly, the adsorption capacity of the former HA fractions on Cu²⁺ were higher than the latter ones, which may be attributed to the difference of carboxyl and phenolic group contents between the former and latter extracted HA fractions. Additionally, the functional groups with N and S should not be neglected. This work is hopeful to understand the environmental effect of humic substances, environmental geochemical behavior, and bioavailability of heavy metals in lakes.

     

Early detection and evaluation of waste through sensorized containers for a collection monitoring application

The present study describes a novel application for use in the monitoring of municipal solid waste, based on distributed sensor technology and geographical information systems. Original field testing and evaluation of the application were carried out in Pudong, Shanghai (PR China).The local waste management system in Pudong features particular requirements related to the rapidly increasing rate of waste production. In view of the fact that collected waste is currently deployed to landfills or to incineration plants within the context investigated, the key aspects to be taken into account in waste collection procedures include monitoring of the overall amount of waste produced, quantitative measurement of the waste present at each collection point and identification of classes of material present in the collected waste. The case study described herein focuses particularly on the above mentioned aspects, proposing the implementation of a network of sensorized waste containers linked to a data management system.Containers used were equipped with a set of sensors mounted onto standard waste bins. The design, implementation and validation procedures applied are subsequently described. The main aim to be achieved by data collection and evaluation was to provide for feasibility analysis of the final device. Data pertaining to the content of waste containers, sampled and processed by means of devices validated on two purpose-designed prototypes, were therefore uploaded to a central monitoring server using GPRS connection. The data monitoring and management modules are integrated into an existing application used by local municipal authorities.A field test campaign was performed in the Pudong area. The system was evaluated in terms of real data flow from the network nodes (containers) as well as in terms of optimization functions, such as collection vehicle routing and scheduling. The most important outcomes obtained were related to calculations of waste weight and volume. The latter data were subsequently used as parameters for the routing optimization of collection trucks and material density evaluation.     

Toxicity of tri- and penta-valent arsenic, alone and in combination, to the cladoceran Daphnia carinata: the influence of microbial transformation in natural waters

The acute toxicity of arsenic(III) and arsenic(V) alone and in combination to a cladoceran, Daphnia carinata, was studied in both cladoceran culture medium and natural water collected from a local suburban stream. As(III) was found to be more toxic than As(V) to Daphnia survival. The LC₅₀ values for As(III), As(V), and As(III) + As(V) were 0.554, 1.499, and 0.692 mg l⁻¹, respectively. Although various species of As, particularly As(III) and As(V) co-exist together in natural waters, the existing guidelines for water quality are based on individual As species. The results of this investigation suggest that As(III) and As(V) can interact either synergistically or additively resulting in an increase in the overall toxicity of the mixture compared to individual As species. Also, indigenous microorganisms in natural water may play a significant role in the transformation of As, thereby influencing the toxicity of As in receiving waters. This study clearly suggests that the joint action of As species should be considered in the development of water quality guidelines. To our knowledge this is the first study on the interactive effect of As(III) and As(V) to a cladoceran. Thus, this study suggests that these two species of As, when present together above 0.1 mg l⁻¹ concentration, are toxic to fresh water invertebrates; therefore, pollution with these compounds may adversely affect natural ecosystems.     

坚持安全发展 推进综合监管——访国家安监总局副局长梁嘉琨

近年来，我国各级安全生产监管部门全面落实科学发展观，坚持安全发展的理念，认真履行安全生产综合监管职能，积极探索开展综合监管工作的措施、途径和手段，逐步构筑了“分类指导、职责明晰、条块结合、运行有序、机制完善”的安全生产综合监管机制和总体格局，全国安全生产综合监管建设取得了长足的进步。但是，在综合监管工作实践中，很多地区也都遇到并提出了同样的问题：《安全生产法》等法律法规中并没有对综合监管的内容作出明确的规定。     

Removal of Cd2+ from water by Friedel's salt (FS:3CaO·Al2O3·CaCl2·10H2O): Sorption characteristics and mechanisms

The development of low-cost and efficient new mineral adsorbents has been a hot topic in recent years.In this study,Friedel's salt (FS:3CaO·Al2O3·CaCl2·10H2O),a hexagonal layered inorganic absorbent,wa...     

辽河口海域叶绿素a的时空分布特征及其影响因素

2013年8月、2013年10月和2014年5月先后3次对辽河口海域进行航次调查,对相关数据运用多种分析方法,研究了浮游植物粒级结构的时空分布特征及其主要环境影响因子。结果表明:辽河口叶绿素a浓度的季节变化特征表现为夏季最大、春季次之、秋季最小。空间分布特征表现为:春季西北部浓度高,东南区域浓度较低;夏秋呈相反的分布特征在夏季为近河口区域低、河口外区域高,且区域之间的浓度差异较大,最大值出现在西南区域;秋季表现为近河口区域高,远离河口区域较低,叶绿素a较大值主要分布在靠近河口的区域。在不同季节,不同粒径对叶绿素a的贡献率也不尽相同,Nano-级对总叶绿素a的贡献率在3个季度中均为最大。影响叶绿素a浓度变化的环境因素复杂:在春季,硝酸盐与叶绿素a呈负相关;在夏季,硝酸盐、磷酸盐、硅酸盐以及总氮均与叶绿素a呈显著负相关,悬浮物浓度与叶绿素a之间呈显著负相关,表层水温(SST)与叶绿素a表现为显著正相关;在秋季,悬浮物(SS)与叶绿素a存在显著正相关。     

基于ABAQUS的钢管活性粉末混凝土短柱轴压受力性能研究

基于ABAQUS工作平台,建立已完成的钢管活性粉末混凝土(RPC)短柱试验试件的有限元模型,对其轴压荷载作用下的受力性能进行分析,将数值计算所得破坏形态、荷载—应变曲线、极限承载力与试验结果进行对比,两者吻合较好。基于此,进一步对钢管和RPC应力—应变曲线进行分析,探讨钢材强度、含钢率和RPC强度对柱轴压性能的影响。结果表明:随着钢材强度和含钢率增加,短柱的极限承载力和残余承载力提高,延性性能改善;RPC强度增加时,试件的极限承载力提高而残余承载力变化不大。最后,根据极限平衡理论建立短柱轴压承载力计算公式,其在0.18ξ2.62范围内适用性较好,可为工程设计提供参考。