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Environmental Science and Pollution Research - Wastewater and effluent discharges are the main causes of receiving water body pollution and important challenges in water quality management. Among...  相似文献   
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Jatropha has gained interest as a potential biodiesel feedstock. Nevertheless, its oil production decreases significantly in frost- and drought-prone regions. In this study, we characterized the flowering pattern of Jatropha in Botswana in the 2014/2015 season. Extensive springtime pruning synchronized Jatropha regrowth in summer and effectively stimulated growth after frost damage. Flowering started in February 2015 and peaked in April and May. Wide variations in flowering frequency were observed among different Jatropha accessions. Trees flowering in February and March produced fruit in May, but most trees only flowered in April and May and did not yield fruit because of cold snaps. These observations suggested that harvesting seed before wintertime is the key to improve Jatropha production in the Botswana climate. This study highlighted the importance of inducing early flowering by developing new agricultural managements. These may include frost cover and sun shades to prevent stress-induced damage, canopy control by pruning, optimization of fertilization practice, and/or introduction of superior Jatropha varieties.  相似文献   
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In this study, we prepared a new adsorbent and evaluated its ability to adsorb Mo(VI). Gibbsite was granulated with colloidal alumina or colloidal silica. The amount of Mo(VI) adsorbed onto granular gibbsite with a binder, effect of contact time and pH on the adsorption of Mo(VI), and column experiments were investigated. The amount of Mo(VI) adsorbed was greater in the order of ST12 (colloidal silica, 12%)?相似文献   
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Prediction accuracy of flow and dispersion around a cubic building with a flush vent located on its roof was examined using various k? models, and numerical results were compared with wind-tunnel data. Four types of turbulence models, i.e., the standard k? model, the RNG k? model, the k? model with Launder and Kato modification and the Realizable k? model were compared in this study. The standard k? model provided inadequate results for the concentration field, because it could not reproduce the basic flow structure, such as the reverse flow on the roof. However, revised k? models provided concentrations in better agreement with the experimental data. The effect of an oblique wind angle and vent locations on the prediction accuracy was also investigated. It was confirmed that the prediction accuracy of the velocity field strongly affected that of the concentration field. The RNG model showed general agreement with the experiment, and was the best of the turbulence models tested. However, it becomes clear that the results for all CFD models show poor prediction accuracy of concentration distribution at the side and leeward surfaces of the building since they all underestimate the concentration diffusion on these regions. The concentrations predicted by all CFD models were less diffusive than those of the experiment.  相似文献   
5.
A detailed analysis of carbohydrates in marine particulate matter   总被引:3,自引:0,他引:3  
Detailed profiles of organic carbon, organic nitrogen, carbohydrate and proteinous amino acid have been determined in particulate matter from various depths at a station in Sagami Nada off eastern Honshu, Japan. The profiles suggest that carbohydrate is decayed from particulate matter more rapidly than proteinous amino acid in the euphotic zone, while the latter is removed to a higher extent than the former in deep waters,which results in the increase of the C/N values of particulate matter in the depths. All of the particulate matter gave D-galactose, D-glucose, D-mannose, D-xylose and D-glucuronic acid upon acid hydrolysis. Vertical change of the monosaccharide composition of this particulate matter indicates that only D-glucose and its polymers are preferentially removed from it during its descent. Carbohydrates from the particulate matter of 20 m depth were fractionated into water-soluble and insoluble carbohydrates. Detailed analysis of these fractions indicates that 1,3-glucan and its related low molecular weight carbohydrates from the water-soluble fraction decay between 50 and 300 m depth, to leave waterinsoluble carbohydrates, immune to biological attack during the course of further sinking. On the basis of these facts, the effects of the biochemical nature of these carbohydrates on the vertical change of the particulate carbohydrate distribution are discussed.  相似文献   
6.
The effectiveness of gibbsite (GB), an amorphous aluminum oxide, for the recovery of Mo(VI) from eluates of fly ash of two coal-fired thermal power stations and of roof tile waste was investigated. Upon the qualitative analysis of an eluate of fly ash, 16 elements were detected. Greater amounts of these elements were eluted under acidic conditions (pH 2) than from the neutral or basic eluate of fly ash. GB was used for the adsorption of Mo(VI). Equilibrium adsorption was reached within 1?min. Optimal solution acidity for the adsorption of Mo(VI) onto GB400 (calcined at 400°C) was pH 2. The main adsorption mechanism was ion exchange with a number of hydroxyl groups of GB400. For repeated ad- and desorption of Mo(VI), GB400 could be used at least four times and the recovery percentage of Mo(VI) with sodium hydroxide solution as eluent surpassed 90%. Our results showed that GB400 was very effective for the recovery of Mo(VI) from fly ash.  相似文献   
7.
We developed a novel polymer type sulfoxide-modified solid phase enabling to achieve selective separation of polychlorinated biphenyls (PCBs) from insulation oil. In this study, firstly we prepared base-polymer based on the concept of the molecular imprinting to capture PCBs in selectively, then, the sulfoxide groups were modified on the pore surface of base-polymers by changing preparation methods. As results of liquid chromatographic analyses for the polymers as columns, the base-polymer prepared by xylene as a porogenic solvent showed selective retention ability for chlorinated aromatic compounds by the porogen imprinting effect. Additionally, the polymer-type sulfoxide solid phases showed highly retention ability for PCBs by increasing amount of introduced sulfoxide groups. Consequently, the results of separation of PCBs comparing to insulation oil suggested that the prepared solid phase can be used for the selective separation of PCBs at the same level as a commercially available media utilized for the regulated method.  相似文献   
8.
OBJECTIVE: Intervertebral Neck Injury Criterion (IV-NIC) hypothesizes that dynamic three-dimensional intervertebral motion beyond physiological limit may cause multiplanar soft-tissue injury. Present goals, using biofidelic whole human cervical spine model with muscle force replication and surrogate head in head-turned rear impacts, were to: (1) correlate IV-NIC with multiplanar injury, (2) determine IV-NIC injury threshold at each intervertebral level, and (3) determine time and mode of dynamic intervertebral motion that caused injury. METHODS: Impacts were simulated at 3.5, 5, 6.5, and 8 g horizontal accelerations of T1 vertebra (n = 6; average age: 80.2 years; four male, two female donors). IV-NIC was defined at each intervertebral level and in each motion plane as dynamic intervertebral rotation divided by physiological limit. Three-plane pre- and post-impact flexibility testing measured soft-tissue injury; that is significant increase in neutral zone (NZ) or range of motion (RoM) at any intervertebral level, above baseline. IV-NIC injury threshold was average IV-NIC peak at injury onset. RESULTS: IV-NIC extension peaks correlated best with multiplanar injuries (P < 0.001): extension RoM (R = 0.55) and NZ (R = 0.42), total axial rotation RoM (R = 0.42) and NZ (R = 0.41), and total lateral bending NZ (R = 0.39). IV-NIC injury thresholds ranged between 1.1 at C0-C1 and C3-C4 to 2.9 at C7-T1. IV-NIC injury threshold times were attained between 83.4 and 150.1 ms following impact. CONCLUSIONS: Correlation between IV-NIC and multiplanar injuries demonstrated that three-plane intervertebral instability was primarily caused by dynamic extension beyond the physiological limit during head-turned rear impacts.  相似文献   
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