Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 31 for “"recovery ratio"”.
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Effect of permeation of discharge characteristics of capacitive deionization process
… it is plagued by the problem of low water recovery ratio. The costs of pumping and pre- and post-treatment of water added to the rising costs of surface water makes maximizing the recovery ratio a priority. Moreover, the throughput of the plant is related to the water recovery ratio. To …
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Two-stage reverse osmosis : optimal element configuration and flux distribution, energy savings
… (system design), and feed pressures (system operation). In this study, we investigate the optimal system design and operation of a two-stage RO system with a mass-balance model and establish a lower bound for the energy savings achieved by the optimized two-stage system compared to a …
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Review of Membrane-Based Brackish Groundwater Desalination and Pretreatment in the United States
… and decrease total costs by increasing its recovery ratio and decreasing membrane maintenance costs. If left untreated, these scalants accumulate on the membranes and require costly removal treatment techniques. Pretreatment requirements vary with feedwater composition, geography, and …
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Autonomous control and membrane maintenance optimization of photovoltaic reverse osmosis systems
… clean water. In this thesis, a controllable recovery ratio concept system has been presented. By actively controlling the PVRO system, an improvement of 47% over the existing performance of a fixed recovery ratio system has been shown in simulations. Use of condition based maintenance …
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Application of a discrete element model to the analysis of granular soil recovery in an offshore tubular vibrocore
… motor. In the past, success of a coring operation has been judged primarily by the length of the recovered core. More recently, studies have given focus to the problems associated with achieving soil specimens in which the in-situ sedimentary structure is preserved. In practice, the core …
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Justification of village scale photovoltaic powered electrodialysis desalination systems for rural India
… chemical contaminant removal; water aesthetics; recovery ratio; energy source; economics of water provision; maintenance; and the energetic and cost considerations of available technologies. Within the salinity range of groundwater in India, ED requires less specific energy than RO (75% less at …
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Split-feed counterflow reverse osmosis for brine concentration
Brine concentration is a useful operation that allows for increased recovery ratios in water treatment systems, reduction of waste volumes, and the production of minerals from saline brines. As our world moves towards a more sustainable future, improvements in energy-efficient brine concentration …
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Modeling nanofiltration for large scale desalination applications
… to develop a comprehensive model for nanofiltration modules. This model allows the user to gain insight into the physics of the nanofiltration process by allowing one to adjust and investigate effects of membrane charge, pore radius, and other membrane characteristics. The study shows how …
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Cost-optimal design of a household batch electrodialysis desalination device
… at lower energy consumption and higher recovery: 80-90% vs 25-40%. Target specifications derived from user-interviews, and RO products, guided the selection of a batch architecture, for which a coupled flow-mass transport model to predict desalination rate was developed, and validated …
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Point of Use Semi-Batch Reverse Osmosis Desalination Prototype Experimental Validation
… significant amounts of wastewater, achieve a recovery of 20-30% of the input feed as drinking water, and consume significant energy. Through previous testing and analysis of a POU RO system, it was identified that recirculating brine within a semi-batch configuration with a brine flushing …
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The suitability of the microalgal metabolism for the recovery of nutrients from wastewater: the implications of solids residence time and diel cycles
The development of technologies for resource recovery from wastewater is an important part of modernizing our water infrastructure to become an integral part of a clean economy. Wastewater is a continuous source of renewable chemical and thermal energy as well as nutrient resources like nitrogen …
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Desalination of brackish groundwater in the United States : minimum energy requirements
… thermodynamic analysis of the least work of separation in order to compute the site-specific least work of separation required for groundwater desalination. Least work of separation represents a baseline for specific energy consumption of real-world desalination systems. Then, we study the …
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Effects of Polybenzoxazine on Properties of Shape-Memory Polyurethanes with Glassy and Crystalline Soft Segments
… However, some factors, such as low values of recovery stress (RS), recovery ratio (RR), and low transition temperature (Ttrans), limit their applications. Researchers focused on improving the shape-memory properties mainly by incorporating nanofillers and chemical additives. In the current …
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Modelling, Simulation and Optimisation of Multistage Humidification and Dehumidification Desalination Plant Using Solar Energy. Performance Evaluation and Improvement of the Humidification-Dehumidification Desalination Process through Modelling, Simulation and Optimisation Techniques
… mathematical analysis, it was observed that the Recovery Ratio (RR) attained was increasing as temperature of the feed water increased. The RR was also increasing with the increase of dehumidifier’s surface area while it decreased with an increase of the packing size. Moreover, through a …
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Saturation curve analysis of humidification-dehumidification desalination systems and analysis of reversible ejector performance
… not easily recognisable. By considering the saturation curve for moist air, a methodology is proposed to graphically understand these limits. A pinch point methodology is employed to evaluate the impact of heat and mass exchanger size upon performance. The impact of salinity upon the design …
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Shape memory polymers with improved shape recovery properties in focused ultrasound fields
… strategies enabling efficient and rapid shape recovery under FUS remain underexplored. This dissertation aims to develop, characterize, and computationally model acrylate-based SMPs and their composites, focusing on enhancing actuation efficiency under FUS. To accommodate miniaturized …
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Thermo-mechanical characterization of carbon-reinforced shape memory polymer
… like shape fixidity (or retention) and shape recovery. In addition, effect of shape recovery at different temperatures, Tg, Tg+15, Tg+30 is also investigated to examine the effect of temperature increase in recovery ratio of the samples. Furthermore, static uniaxial tensile tests are performed …
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Mapping the Electrodialysis Architecture Design Space by Determining Optimal System Configurations for Different Production Outputs
… was proposed and explored called hybrid operation that utilizes the benefits from both continuous and batch operation. Additionally, this framework can also be used to identify the most cost-effective strategy for employing batteries and managing the energy stored versus used for …
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Use of polymeric membranes for the treatment of oily wastewater: Modification using inorganic nanoparticles and optimization of filtration parameters
… common problems, such as nanoparticle agglomeration or leaching and the formation of defective areas, may occur during the membrane fabrication. These issues depend on several factors which were observed to influence the membrane morphology and structure and consequently influence the …
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Hydrothermal liquefaction of wastewater algae mixtures into bio-crude oil
… composition, reaction pathways and nutrient recovery via hydrothermal liquefaction (HTL) were investigated. HTL was conducted at temperatures scan of 260 to 320 ˚C between 0 to 1.5 hour retention time at 0.7 MPa N2 initial pressures. The highest bio-crude oil yield, 49 %, produced from AW …
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