共查询到20条相似文献,搜索用时 15 毫秒
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Bauder TA Barbarick KA Ippolito JA Shanahan JF Ayers PD 《Journal of environmental quality》2005,34(5):1687-1696
Oil and gas drilling operations use drilling fluids (mud) to lubricate the drill bit and stem, transport formation cuttings to the surface, and seal off porous geologic formations. Following completion of the well, waste drilling fluid is often applied to cropland. We studied potential changes in soil compaction as indicated by cone penetration resistance, pH, electrical conductivity (EC(e)), sodium adsorption ratio (SAR), extractable soil and total straw and grain trace metal and nutrient concentrations, and winter wheat (Triticum aestivum L. 'TAM 107') grain yield following water-based, bentonitic drilling-fluid application (0-94 Mg ha(-1)) to field test plots. Three methods of application (normal, splash-plate, and spreader-bar) were used to study compaction effects. We measured increasing SAR, EC(e), and pH with drilling-fluid rates, but not to levels detrimental to crop production. Field measurements revealed significantly higher compaction within areas affected by truck travel, but also not enough to affect crop yield. In three of four site years, neither drilling-fluid rate nor application method affected grain yield. Extractions representing plant availability and plant analyses results indicated that drilling fluid did not significantly increase most trace elements or nutrient concentrations. These results support land application of water-based bentonitic drilling fluids as an acceptable practice on well-drained soils using controlled rates. 相似文献
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Ye-Qiang Zhang Wei He Guo-Dong Xia Chong-Fang Ma Yan-Hai Peng 《International Journal of Green Energy》2015,12(3):257-264
A single-screw expander has been designed and manufactured independently. Based on this prototype, testing system has been built and performance experiment has been made. In this article, compressed air was used as working fluid and performance test for the prototype was finished at conditions including different rotational speed and different inlet pressure.From the experimental data, it is shown that when inlet pressure less than 0.8MPa the output power increases with the increase of rotational speed because of not enough expansion; when inlet pressure more than 0.8MPa, the every biggest output power is appeared in the condition of rotational speed 2600 rpm. The test results also show that the total efficiency is influenced by rotational speed obviously, and the highest total efficiency of this machine is 69.64% in the condition of 3000 rpm and 15 bar. 相似文献
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Sheng-Wei Fei 《International Journal of Green Energy》2020,17(10):583-590
ABSTRACT In order to improve the prediction ability for the monthly wind speed of RVR, the hybrid model of empirical wavelet transform and relevance vector regression (EWT-RVR) is proposed for monthly wind speed prediction in this study. Compared with empirical mode decomposition (EMD), empirical wavelet transform (EWT) can obtain a more consistent decomposition and have a mathematical theory. In order to testify the superiority of EWT-RVR, several traditional RVR models are used to compare with the proposed EWT-RVR method under the situation of the same embedding dimensions. The experimental results show that the proposed EWT-RVR method has a better prediction ability for monthly wind speed than RVR. It can be concluded that the proposed EWT-RVR method for monthly wind speed is effective. 相似文献
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通过野外观测实验探讨了戈壁地表风沙运动的若干特征。结果表明:戈壁地表风沙活动层主要集中在距地表60 cm高度内;不同粒径沙粒输沙强度的垂向分布不同,以0.25~0.5mm为过渡区,0.25mm颗粒输沙强度随高度增大先增加而后按指数规律递减,0.5mm颗粒则随高度增加呈线性递减,且粒径越大,递减的梯度越小;风沙流中颗粒的粒度组成不仅受风速和颗粒起动风速影响,而且还与地表粒度组成直接相关;输沙率与风速之间关系服从指数规律,公式形式为q=α.eβ.u,其中α、β为相关系数,u为地面2m高处风速。 相似文献
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Mohamed Ahmed Reda Hamed 《环境质量管理》2023,32(3):203-208
Due to its simplicity and accurately measuring the flow rate, the venturi system is a special kind of pipe that is widely used in various applied fluid mixtures. One of the venturi system's important applications is ejectors devices that accurately facilitate adding air to water to sustain oxygen demand target levels in many waterworks engineering systems. This study aims to improve venturi system measurement accuracy through experimental investigation and analytical analysis for the venturi system conditional configuration parameters effect on target aeration operational efficiency. In the experiment work, different runs are implemented to characterize the performance of such aerators by describing the impact of venturi characteristics and configurations, including water flow rate, air inlets orifices diameters, inlet velocities, throat lengths, inlet angles, outlets angles, and outlet diameters on aeration efficiency. Results show that the venturi air vent diameter is an important governing parameter for determining aeration performance value. Additionally, an indicated increase in aeration performance with an increasing throat length to its diameter ratio. Meanwhile, the results revealed a varying noted effect of the venturi system characteristics and configurations on aeration performance. Moreover, the equations that relate venturi system configuration and Reynolds numbers with the aeration operational performance are developed to facilitate the target accurate aeration efficiency estimation. 相似文献
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Hsu-Hsiang Cheng Jui-Fu Shen Chung-Sung Tan 《International Journal of Greenhouse Gas Control》2010,4(3):525-531
The capture of CO2 from a hot stove gas in steel making process containing 30 vol% CO2 by chemical absorption in a rotating packed bed (RPB) was studied. The RPB had an inner diameter of 7.6 cm, an outer diameter of 16 cm, and a height of 2 cm. The aqueous solutions containing 30 wt% of single and mixed monoethanolamine (MEA), 2-(2-aminoethylamino)ethanol (AEEA), and piperazine (PZ) were used. The CO2 capture efficiency was found to increase with increasing temperature in a range of 303–333 K. It was also found to be more dependent on gas and liquid flow rates but less dependent on rotating speed when the speed was higher than 700 rpm. The obtained results indicated that the mixed alkanolamine solutions containing PZ were more effective than the single alkanolamine solutions. This was attributed to the highest reaction rate of PZ with CO2. A higher portion of PZ in the mixture was more favorable to CO2 capture. The highest gas flow rates allowed to achieve a desired CO2 capture efficiency and the correspondent height of transfer unit (HTU) were determined at different aqueous solution flow rates. Because all the 30 wt% single and mixed alkanolamine solutions could result in a HTU less than 5.0 cm at a liquid flow rate of 100 mL/min, chemical absorption in a RPB instead of a packed bed adsorber is therefore suggested to capture CO2 from the flue gases in steel making processes. 相似文献
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吹脱法应用于低浓度废水处理,可有效去除水中的溶解性气体和挥发性油类,同时还可增加水中的溶解氧,为进一步的生物处理创造有利条件。利用现场动态实验对影响除油的因素进行了试验研究,确定最佳处理条件为:气水比5∶1、淋水密度5.0m3/(m2·h),实验表明在最佳运行状态下,吹脱法对地下水中油类物质的去除率能够达到50%,还能去除水中的铁、氨氮等污染物质,是一种非常有效的预处理方法。为了弄清目前炼油厂废水的处理水平,通过对三个典型炼油废水处理厂的调查,分别对其处理流程、处理效果、采用的主要处理药剂及处理工艺进行了介绍,分析了每套处理设施的长处以及与先进设施对比存在的不足。 相似文献
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In this work, a novel multipurpose Faujasite (FAU) zeolite composite membrane was fabricated by in-situ hydrothermal method to separate different solute molecules such as vanillic acid, phenol, and brilliant green from the aqueous solution. The coal fly ash based ceramic substrate was synthesized and used as substrate for preparing the zeolite composite membrane. The X-ray diffraction (XRD) pattern confirmed the crystalline nature of membranes and the presence of Quartz and hematite in the composite membrane. The presence of Si-O and Al-O in zeolite coated composite membrane was confirmed by Fourier Transform infrared spectroscopy (FTIR) analysis. Scanning electron microscope (SEM) analysis showed the porous structure and 8.34 μm thickness of zeolite coating on membrane. The isoelectric point of composite membrane was observed at pH 2.07 through zeta potential analysis. Brunauer-Emmett-Teller (BET) surface area, average pore volume and pore diameter of zeolite composite membrane were estimated as 6.406 m2/gm, 0.0070 cm3/gm, and 4.371 nm, respectively. The hydraulic pore radius and porosity of composite membranes were 27.7 nm and 20.1%. The maximum separation efficiency of FAU zeolite composite membrane towards vanillic acid, phenol and brilliant green was estimated as 78.67%, 89.13%, and 94.28%, respectively, for 200 mg/L feed concentration at 276 kPa applied pressure. The results obtained in this study reveals that the multipurpose FAU zeolite composite membrane fabricated in this study can be effectively used for separation of various solutes molecules present in the wastewater. 相似文献
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Xinjie Wang Yuwen Guo Jingyang Liu Qi Qiao Jijun Liang 《Journal of environmental management》2010,91(12):2505-2510
The study is directed to the use of non-metallic powders obtained from comminuted recycled paper-based printed circuit boards (PCBs) as an additive to polyvinyl chloride (PVC) substrate. The physical properties of the non-metallic PCB (NMPCB) powders were measured, and the morphological, mechanical and thermal properties of the NMPCB/PVC composite material were investigated. The results show that recycled NMPCB powders, when added below a threshold, tended to increase the tensile strength and bending strength of PVC. When 20 wt% NMPCB powders (relative to the substrate PVC) of an average diameter of 0.08 mm were added, the composite tensile strength and bending strength reached 22.6 MPa and 39.83 MPa, respectively, representing 107.2% and 123.1% improvement over pure PVC. The elongation at break of the composite material reached 151.94% of that of pure PVC, while the Vicat softening temperature of the composite material did not increase significantly compared to the pure PVC. The above results suggest that paper-based NMPCB powders, when used at appropriate amounts, can be effective for toughening PVC. Thus, this study suggests a new route for reusing paper-based NMPCB, which may have a significant beneficial environmental impact. 相似文献
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AbstractElectric vehicles (EVs) are currently being discussed as a promising means to increase the energy efficiency and sustainability of today's transport systems. While technological progress and cost reduction are certainly crucial topics for their successful diffusion, consumer acceptance is another issue that warrants further analysis. Based on a large online survey (N?=?969), we compared four consumer groups which differ in their likelihood to purchase an EV with regard to their socio-demographic characteristics, their willingness to pay (WTP) and their perceptions of EVs. The findings indicate that early users in Germany are most likely to be middle-aged men living with their families in a multi-vehicle household who have a higher WTP for an EV. Perceived compatibility of an EV with personal needs seems to be the most influential factor on the stated willingness to purchase an EV. With regard to the promotion of EVs, strengthening their environmental advantages and providing financial incentives for purchase are rated as important measures by a majority of the sample, while performance characteristics which are comparable to conventional vehicles seem to be less important for most participants. Based on the data analyses, we provide recommendations for measures regarding the further development and promotion of EVs. 相似文献
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Xinyou Lin Guangji Zhang Shenshen Wei Yanli Yin 《International Journal of Green Energy》2020,17(8):488-500
ABSTRACT The drive range of electric vehicle (EV) is one of the major limitations that impedes its universalism. A great deal of research has been devoted to drive range improvement of EV, an accurate and efficiency energy consumption estimation plays a crucial role in these researches. However, the majority of EV’s energy consumption estimation models are based on single motor EV, these models are not suitable for dual-motor EVs, which are composed of more complex transmission mechanisms and multiple operating modes. Thus, an energy consumption estimation model for dual-motor EV is proposed to estimate battery power. This article focuses on studying the operating modes and system efficiency in each operating mode. The limitation of working area of each mode ensures the vehicle dynamic performance, then PSO algorithm is adopted to optimize the torque (speed) distribution between two motors to improve the system efficiency in the coupled driving mode. Finally, the energy consumption estimation model is established by multiple linear regression (MLR). The result shows that the proposed model has a high precision in energy consumption estimation of dual-motor EV. 相似文献
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Kyla Tienhaara 《Journal of Environmental Policy & Planning》2020,22(1):112-124
ABSTRACTThe conventional view of transparency is that it is a critical tool to combat corruption and ensure the democratic accountability of government. This article argues that the negotiation of mega-regional trade agreements (RTAs) and their content indicates the need distinguish different types of transparency. Trade activists that call for drafts of the text of a mega-RTA to be released while negotiations are ongoing are seeking deliberative transparency, which provides opportunities for meaningful public participation and consultation. The trade advisory systems that could provide opportunities for deliberation instead deliver technocratic transparency; the rationale is to increase the effectiveness of mega-RTAs rather than their democratic legitimacy. Frequent leaks of draft chapters of mega-RTAs provide opportunities for deliberation, but some actors involved in leaking are engaged in disruptive transparency where the aim is to complicate trade negotiations, making a final deal less likely. While these varieties of transparency emerge in the context of the negotiating process, disciplinary transparency – which often becomes a regulatory tool for multinational corporations to influence policy-making – is found in the text of mega-RTAs. Certain forms of transparency increase the likelihood that mega-RTAs will be compatible with strong environmental policy, while others may have a detrimental impact. 相似文献
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M. Lati S. Boughali D. Bechki H. Bouguettaia D. Mennouche N. Gana 《International Journal of Green Energy》2019,16(6):413-422
A passive flat-plate solar air collector was constructed in the laboratory of New and Renewable Energy in Arid Zones, Ouargla University, South East Algeria. The absorber of the passive flat-plate solar air collector was laminated with a thin layer of local sand. This acted as a thermal packed bed with a collecting area of 0.5 m2 (1 m × 0.5 m). Three series of experiments were performed. The first consisted of choosing the best sand brought from three different places of the Algerian desert. The second consisted of studying the effect of the thickness of the sand layer on the daily efficacy of the collector. The influence of the sand diameter was investigated in the third series. The experimental results showed that: All collectors covered with sand had higher efficiency than those without. It was noticed that, for a fixed mass of sand (given thickness of the sand layer), the improvement of the collector was inversely proportional to the sand particle diameters. The maximum efficiency approximates 62.1% for a particle diameter 0.063 mm, compared to 41.71% for a diameter 0.250 mm.The efficiency of the collector for a fixed particle diameter increases with the increase in the thickness of the sand layer. The collector with thickness sand layer 0.84 mm gave the best efficiency of 46.14% compared to 27.8% for 0.28 mm of thickness sand layer. 相似文献