Dissertations / Theses on the topic 'Engineering novel membrane system'
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HOWARD, SHAUN CHRISTOPHER. "PHASE SEPARATION IN MIXED ORGANOSILANE MONOLAYERS: A MODEL SYSTEM FOR THE DEVELOPMENT OF NOVEL MEMBRANES." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1123873986.
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Millward, Huw Richard. "Novel membrane bioreactors." Thesis, University of Oxford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317837.
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Lloyd, Michael C. "Novel materials for membrane separation processes." Thesis, Aston University, 1995. http://publications.aston.ac.uk/9680/.
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The aim of this work was to synthesise a series of hydrophilic derivatives of cis-1,2-dihydroxy-3,5-cyclohexadiene (cis-DHCD) and copolymerise them with 2-hydroxyethyl methacrylate (HEMA), to produce a completely new range of hydrogel materials. It is theorised that hydrogels incorporating such derivatives of cis-DHCD will exhibit good strength and elasticity in addition to good water binding ability. The synthesis of derivatives was attempted by both enzymatic and chemical methods. Enzyme synthesis involved the transesterification of cis-DHCD with a number of trichloro and trifluoroethyl esters using the enzyme lipase porcine pancreas to catalyse the reaction in organic solvent. Cyclohexanol was used in initial studies to assess the viability of enzyme catalysed reactions. Chemical synthesis involved the epoxidation of a number of unsaturated carboxylic acids and the subsequent reaction of these epoxy acids with cis-DHCD in DCC/DMAP catalysed esterifications. The silylation of cis-DHCD using TBDCS and BSA was also studied. The rate of aromatisation of cis-DHCD at room temperature was studied in order to assess its stability and 1H NMR studies were also undertaken to determine the conformations adopted by derivatives of cis-DHCD. The copolymerisation of diepoxybutanoate, diepoxyundecanoate, dibutenoate and silyl protected derivatives of cis-DHCD with HEMA, to produce a new group of hydrogels was investigated. The EWC and mechanical properties of these hydrogels were measured and DSC was used to determine the amount of freezing and non-freezing water in the membranes. The effect on EWC of opening the epoxide rings of the comonomers was also investigated
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Mustapha, Rasha. "Hybrid refrigeration system with a novel membrane exchanger." Thesis, Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEM073.
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L'objectif principal de cette thèse est de proposer une méthodologie et un outil de modélisation pour concevoir des systèmes hybrides de réfrigération et de climatisation à haute performance, abordables et flexibles. Il se concentre sur des systèmes hybrides basés sur le couplage d'un cycle de dessiccation et un cycle de compression de vapeur permettant un contrôle efficace de l'humidité dans les applications de climatisation et un fonctionnement sans givre dans les applications de réfrigération. Le travail a été développé pour étudier une nouvelle conception d'un échangeur membranaire de chaleur et de masse à l'aide de membranes originales et d'une nouvelle conception liée à la distribution de liquide. La conception tire parti des matériaux à faible coût qui sont testés expérimentalement à l'aide d'une nouvelle méthodologie pour déduire leur perméabilité de la vapeur d'eau qui affecte significativement le transfert de masse. Un prototype de l'échangeur membranaire proposé est alors construit et une approche de modélisation des phénomènes de transfert de chaleur et de masse est développée et appuyée par des caractérisations expérimentales. Ce modèle est ensuite utilisé pour étudier l'intérêt énergétique de l'intégration de ces échangeurs dans les applications de climatisation et pour concevoir une architecture flexible capable de faire face à la variation saisonnière du rapport de charge latente à sensible. Les résultats montrent que le système hybride étudié présente des solutions alternatives prometteuses comparé aux cycles conventionnels, où ils peuvent améliorer de façon significative les performances et réduire la consommation d'électricitéThe major objective of this thesis is to propose a methodology and a modeling tool to design high performance, affordable and flexible hybrid refrigeration and air conditioning systems. It focuses on hybrid systems based on coupling a desiccant cycle with a vapor compression cycle allowing an efficient humidity control in air conditioning applications and a frost free operation in refrigeration applications. The work was developed to investigate a novel design of a membrane based heat and mass exchanger using original membrane materials and new design related to liquid distribution. The design takes advantage of materials with low cost that are experimentally tested using a new methodology to infer their water vapor permeability that greatly affects the mass transfer. A prototype of the designed membrane exchanger is then built and a modeling approach of the heat and mass transfer phenomena is developed and is supported by experimental characterization. This model is then used to study the energy interest of the integration of these exchangers in air conditioning applications and to design a flexible architecture able to cope with the seasonal variation of the latent to sensible load ratio. The results show that the studied hybrid system present promising alternatives for conventional cycles where they can significantly improve the performance and decrease the consumption of electricity
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Ramraj, Varun. "Exploiting whole-PDB analysis in novel bioinformatics applications." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:6c59c813-2a4c-440c-940b-d334c02dd075.
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The Protein Data Bank (PDB) is the definitive electronic repository for experimentally-derived protein structures, composed mainly of those determined by X-ray crystallography. Approximately 200 new structures are added weekly to the PDB, and at the time of writing, it contains approximately 97,000 structures. This represents an expanding wealth of high-quality information but there seem to be few bioinformatics tools that consider and analyse these data as an ensemble. This thesis explores the development of three efficient, fast algorithms and software implementations to study protein structure using the entire PDB. The first project is a crystal-form matching tool that takes a unit cell and quickly (< 1 second) retrieves the most related matches from the PDB. The unit cell matches are combined with sequence alignments using a novel Family Clustering Algorithm to display the results in a user-friendly way. The software tool, Nearest-cell, has been incorporated into the X-ray data collection pipeline at the Diamond Light Source, and is also available as a public web service. The bulk of the thesis is devoted to the study and prediction of protein disorder. Initially, trying to update and extend an existing predictor, RONN, the limitations of the method were exposed and a novel predictor (called MoreRONN) was developed that incorporates a novel sequence-based clustering approach to disorder data inferred from the PDB and DisProt. MoreRONN is now clearly the best-in-class disorder predictor and will soon be offered as a public web service. The third project explores the development of a clustering algorithm for protein structural fragments that can work on the scale of the whole PDB. While protein structures have long been clustered into loose families, there has to date been no comprehensive analytical clustering of short (~6 residue) fragments. A novel fragment clustering tool was built that is now leading to a public database of fragment families and representative structural fragments that should prove extremely helpful for both basic understanding and experimentation. Together, these three projects exemplify how cutting-edge computational approaches applied to extensive protein structure libraries can provide user-friendly tools that address critical everyday issues for structural biologists.
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Banks, Stacie. "The treatment of landfill leachate using an MFUF membrane system: Focusing on membrane fouling." Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/26572.
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Membrane systems are being used increasingly throughout the western world to treat landfill leachate as environmental regulations tighten. This work examined leachate filtration using a bench-scale MF/UF membrane system, focussing on surface fouling and constituent reductions at the Trail Road Landfill in Ottawa, Ontario.
The study found that ultrafiltration membranes with a molecular weight cut-off of 10 KDa and below gave the best overall leachate treatment. A 1 KDa ultrafiltration membrane gave the highest percent removals overall of all the membranes tested, but had one of the lowest steady state fluxes ranging from 2 to 5 L/m2h.
Carbonates such as calcite and dolomite were determined to be one of the main foulants/scalants. Iron sulphides or iron oxides tended to form a general coating over the membrane surface and may have been the base for a surface coating of mixed-element origins observed in spring 2003. The fouling type was generally thought to be cake filtration based on flux results and basic fouling determination equations. (Abstract shortened by UMI.)
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Shahriari, Zavareh Haleh. "Evaluation and modeling of a membrane activated sludge system." Thesis, University of Ottawa (Canada), 2003. http://hdl.handle.net/10393/26395.
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A membrane activated sludge bench-scale system was used to treat a complex synthetic wastewater over a wide range of operating conditions ranging 1 to 15 day(s) solids retention time (SRT) and 4 to 12 hours hydraulic retention time (HRT). Although the membrane reactor was able to provide good to excellent separation of particulates from the liquid in the mixed liquor over these operating conditions, the membrane failed, primarily due to clogging at operating conditions outside of these ranges. Various techniques, such as coagulant addition, were attempted to further expand the operating range but they failed. All runs were conducted until steady state conditions existed at which time data for modelling were collected. Performance of the system primarily for carbon and nitrogen removal is described for conditions where solids loss or clogging was nonproblematic. Different mathematical models to predict the behaviour of an activated sludge system and to estimate stoichiometric and kinetics parameters are presented. (Abstract shortened by UMI.)
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Smith, Shaleena. "Pilot assessment of Novel Membrane Bioreactor Processes - Improvements in Biological Nutrient Removal and Membrane Operation." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3357.
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With increasing water reuse applications and upcoming stringent regulations for treated wastewater effluent discharge, wastewater plants need to consider alternative technologies beyond conventional treatment processes. The new regulations, Numeric Nutrient Criteria (NNC), may regulate discharge nitrogen and phosphorus concentrations to as low as 0.5 mg/L as N and 10 μg/L as P respectively. To meet these target requirements, system retrofitting to incorporate chemical or advanced nutrient removal systems possibly with membrane technology will most likely be required. Although microfiltration/ultrafiltration membranes coupled with biological processes, otherwise known as membrane bioreactors (MBR), remove contaminants and suspended solids, nutrient removal is minimal to none. This emphasizes the importance of the biological process in MBRs. This study evaluated and tested the improvement of biological nutrient removal (BNR) in an MBR system which can meet NNC regulations along with the optimization of membrane operation for the reduction of fouling and energy consumption.
A pilot study was conducted at the City of Tampa wastewater treatment plant and was divided into four phases of experimentation using two submerged MBR membranes operated with modified biological configurations. Laboratory analyses and data collection were conducted during the experiments and the performance evaluated for each configuration. System configurations were also optimized throughout each phase of testing for nutrient removal. Important factors used in the development of an appropriate configuration included isolation of the membrane tank from the biological reactors in the design, control of the dissolved oxygen (DO) concentrations or specifically the oxidation reduction potential (ORP) during operation and appropriate internal recirculation rates between the reactors.
The results of this study provided information relevant for the assessment of both the BNR process and membrane performance. Membrane performance data indicated the importance and effect of air scouring (despite energy consumption) on membrane fouling for long-term stable flux operation as well as the cleaning frequency whether chemical enhanced backwash (CEB) or clean-in-place (CIP). This assessment also discussed how BNR systems can be enhanced through the incorporation of important design factors to eliminate the inhibiting factors of nitrogen and phosphorus removal such as dissolved oxygen. One of the biological processes tested in this study achieved effluent nitrogen and phosphorus concentrations below 5 mg/L and 1 mg/L respectively. Although the process tested did not meet NNC criteria, it can be applied with chemical precipitation. This, in turn, can reduce the operating and maintenance (O&M) costs associated with the chemical precipitation of phosphorus.
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Andhee, Avinash. "A novel compact Shearographic NDT system." Master's thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/5546.
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Includes bibliographical referencesThere is a need in industry and the NDT (Non-destructive Testing) community for quick, reliable, user-friendly and cost-effective compact NDT systems that can be used on a wide variety of materials and structures, for quality assurance and maintenance. Designing and building a compact Shearographic NDT system will enhance the capability of inspection during quality assurance and maintenance routines as well as reduce inspection time. Older compact Shearographic systems, which have been tested satisfactorily both under laboratory and field conditions at the NDT Laboratory at the University of Cape Town, have a rather restricted field of view. This is due to the proprietary shearing optics being placed in front of the camera lens, which in other words means that the field of view can only be increased by using a relatively small focal length camera lens which results in having to increase the size of the shearing optics. This would make the compact Shearographic device much larger which is counter-productive since technology enables/directs research and development toward more compact devices.
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Du, Preez Ryne. "Development of a membrane immobilised amidase bioreactor system." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/1996.
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Chen, Lian. "A novel method for power system stabilizer design." Doctoral thesis, University of Cape Town, 2003. http://hdl.handle.net/11427/5261.
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Word processed copy.Includes bibliographies.
Power system stability is defined as the condition of a power system that enables it to remain in a state of operating equilibrium under normal operating conditions and to regain an acceptable state of equilibrium after being subjected to a finite disturbance. In the evaluation of stability, the focus is on the behavior of the power system when subjected to both large and small disturbances. Large disturbances are caused by severe changes in the power system, e.g. a short-circuit on a transmission line, loss of a large generator or load, loss of a tie-line between two systems. Small disturbances in the form of load changes take place continuously requiring the system to adjust to the changing conditions. The system should be capable of operating satisfactorily under these conditions and successfully supplying the maximum amount ofload. This dissertation deals with the use of Power System Stabilizers (PSS) to damp electromechanical oscillations arising from small disturbances. In particular, it focuses on three issues associated with the damping of these oscillations. These include ensuring robustness of PSS under changing operating conditions, maintaining or selecting the structure of the PSS and coordinating multiple PSS to ensure global power system robustness.
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Balakrishnan, Prabhuraj. "Engineering the membrane electrode assembly of direct methanol fuel cells using novel graphene architecture." Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/engineering-the-membrane-electrode-assembly-of-direct-methanol-fuel-cells-using-novel-graphene-architecture(2088d92c-3891-4eb6-bc2b-5b1c71f4a2f6).html.
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This research focuses on improving direct methanol fuel cell (DMFC) performance by using graphene based materials in their membrane electrode assembly (MEA). The main obstacles of commercialization, poor electrode kinetics and the fuel crossover are addressed by using reduced graphene oxide (rGO) in the cathode microporous layer and single layer graphene (SLG) as an anode barrier layer. In the microporous layer work, an rGO (by hydroiodic acid (HI) reduction of graphene oxide) coated electrode exhibited higher conductivity than conventionally used Ketjen Black electrode (standard). The MEA containing rGO produced peak power density of 79 ± 3 mW cm-2 compared to the standard MEA performance of 55 ± 3 mW cm-2 (44 % improvement) at 70 °C, 1 M methanol fuel cell operating conditions. Doping rGO with boron (B-rGO) or nitrogen (N-rGO) by boric acid and nitric acid treatment and utilizing them as electrodes produced peak power density of 90 ± 3 mW cm-2 for B-rGO (63 % improvement) and 101 ± 3 mW cm-2 for N-rGO (84 % improvement) respectively. This is attributed to the higher conductivity of doped rGO electrodes than rGO, owing to the replacement of heteroatoms in their graphene lattice, with detected boron and nitrogen levels at 2 at% and 6 at%, evidenced by x-ray photoelectron spectroscopy (XPS), aiding in improved electron transfer. In the barrier layer work, SLG added onto the anode side of the MEA, reduced methanol permeation from 1.72 ± 0.1 x 10-7 mol cm-2 s-1 (for the standard) to 1.21 ± 0.1 x 10-7 mol cm-2 s-1, with negligible resistance to protons observed at 70 °C, leading to 45 % improvement in power density (77 ± 1 mW cm-2), caused by the dense carbon lattice packing and single layer nature of SLG. Preliminary results using hexagonal boron nitride (hBN), showed that the cell performance improved by 18 %. Overall, it is evident from the performance improvement results that these graphene materials (first ever reported to have used in the MEA of a DMFC) hold great promise for paving the way towards DMFC commercialization by increasing the electrode kinetics (in case of rGO usage) and reducing methanol permeation (in case of SLG usage).
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Rukas, Christopher J. "Prognostic Health Assessment of an Automotive Proton Exchange Membrane Fuel Cell System." Thesis, Rochester Institute of Technology, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1586450.
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Proton exchange membrane fuel cells are a promising technology for the automotive industry. However, it is necessary to develop effective diagnostic tools to improve system reliability and operational life to be competitive in the automotive market. Early detection and diagnosis of fuel cell faults may lead to increased system reliability and performance. An efficient on-line diagnosis system may prevent irreparable damage due to poor control and system fatigue. Current attempts to monitor fuel cell stack health are limited to specialized tests that require numerous parameters. An increased effort exists to minimize parameter input and maximize diagnostic robustness. Most methods use complex models or black-box methods to determine a singular fault mode. Limited research exists with pre-processing or statistical methods. This research examines the effectiveness of a Naïve Bayes classifier on determining multiple states of health; such as healthy, dry, degraded catalyst, and inert gas build-up. Independent component analysis and principal component analysis are investigated for preprocessing. An automotive style fuel cell model is developed to generate data for these purposes. Since automotive applications have limited computational power, a system that minimizes the number of inputs and computational complexity is preferred.
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ElSaadany, Mohamed. "A NOVEL IoT-BASED WIRELESS SYSTEM TO MONITOR HEART RATE." Miami University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=miami1501023035755156.
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Fuller, Anshuman. "Novel Perovskite-based electro-catalysts for Oxidative Dehydrogenation (ODH) of Ethane in an Electrochemical Membrane Reactor." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1439880541.
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Eavarone, David A. (David Alan). "A novel nanodelivery system for combination tumor therapy." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/34158.
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Thesis (S.M.)--Massachusetts Institute of Technology, Biological Engineering Division, 2004.Includes bibliographical references (leaves 36-38).
Anti-angiogenic therapy offers many benefits over traditional cytotoxic chemotherapy including fewer toxic side effects and the reduced development of drug resistance. Anti-angiogenics alone have not proven effective in inducing tumor regression in the clinic due to both the cytostatic nature of anti-angiogenic therapy and the potential formation of new regions of hypoxia within the tumor after therapy. The new therapeutic paradigm is for combining both anti-angiogenics and traditional cytotoxic agents for a synergistic effect. The efficacy of cytotoxic agents may be reduced after anti-angiogenic therapy, however, due to limited access to tumor vasculature and hypoxia-induced drug resistance. We propose that loading cytotoxic agents within the tumor prior to blood vessel collapse will enable both greater drug accumulation within the tumor as well as a reduction in the formation of therapy-induced regions of hypoxia. We present here a novel nanodelivery vehicle termed a 'nanocell' for the spatio-temporal recruitment of both anti-angiogenics and cytotoxic agents within the solid tumor to achieve this goal. Nanocells consist of a polymeric nanocore encapsulating the cytostatic agent doxorubicin surrounded by a lipid vesicle containing the anti-angiogenic agent combretastatin A4.
(cont.) Nanocell treatment resulted in an 88% reduction in tumor size in vivo, compared to a 66% reduction in tumor size after delivering combretastatin A4 lipid vesicles and doxorubicin nanocores simultaneously but separately. Nanocell treatment also resulted in a significant reduction in systemic toxicity, fewer metastases to the lung and liver, and a greater degree of tumor apoptosis.
by David A. Eavarone.
S.M.
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Petra, Mohamad Iskandar. "Novel hardwired distributive tactile sensing system for medical applications." Thesis, Aston University, 2007. http://publications.aston.ac.uk/12240/.
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This thesis described the research carried out on the development of a novel hardwired tactile sensing system tailored for the application of a next generation of surgical robotic and clinical devices, namely a steerable endoscope with tactile feedback, and a surface plate for patient posture and balance. Two case studies are examined. The first is a one-dimensional sensor for the steerable endoscope retrieving shape and 'touch' information. The second is a two-dimensional surface which interprets the three-dimensional motion of a contacting moving load. This research can be used to retrieve information from a distributive tactile sensing surface of a different configuration, and can interpret dynamic and static disturbances. This novel approach to sensing has the potential to discriminate contact and palpation in minimal invasive surgery (MIS) tools, and posture and balance in patients. The hardwired technology uses an embedded system based on Field Programmable Gate Arrays (FPGA) as the platform to perform the sensory signal processing part in real time. High speed robust operation is an advantage from this system leading to versatile application involving dynamic real time interpretation as described in this research. In this research the sensory signal processing uses neural networks to derive information from input pattern from the contacting surface. Three neural network architectures namely single, multiple and cascaded were introduced in an attempt to find the optimum solution for discrimination of the contacting outputs. These architectures were modelled and implemented into the FPGA. With the recent introduction of modern digital design flows and synthesis tools that essentially take a high-level sensory processing behaviour specification for a design, fast prototyping of the neural network function can be achieved easily. This thesis outlines the challenge of the implementations and verifications of the performances.
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Elmer, Theo. "A novel SOFC tri-generation system for building applications." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/30516/.
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In response to the critical need to decarbonise the built environment, alternative methods for more effective energy utilisation need to be explored including tri-generation systems. Tri-generation is the simultaneous generation of electricity, heating and/or cooling from a single fuel source. Solid oxide fuel cell (SOFC) and liquid desiccant demonstrate many characteristics that make them an attractive option in the development of an efficient and effective tri-generation system. SOFCs have high operational electrical efficiencies and a thermal output in good agreement with the low temperature regeneration requirement of liquid desiccants. The aim of this thesis is to design, develop and test an efficient and effective proof of concept tri-generation system based on SOFC and liquid desiccant air conditioning technology for building applications. An extensive review of the literature shows that no previous work has been reported on such a system. The research has critically examined, both theoretically and experimentally, the novel tri-generation system concept. Simulations show tri-generation system efficiencies of up to 71% are achievable at a 1.5kWe capacity, which are encouraging values for a system of this size. An integration analysis, based on empirical data, provides good agreement with the simulations. At a 1.5kWe output, a tri-generation efficiency of 69% has been demonstrated. The inclusion of liquid desiccant air conditioning provides an efficiency increase of up to 15% compared to SOFC electrical operation only, demonstrating the merit of the novel tri-generation system in applications that require simultaneous electrical power, heating and dehumidification/cooling. An experimental system, using a micro-tubular SOFC shows the novel system can generate 150W of electrical power, 443W of heat or 279W of cooling. Instantaneous tri-generation system efficiency is low at around 25%. This is primarily due to the low capacity and poor performance of the micro-tubular SOFC. Although the performance is low, the experimental results demonstrate regeneration of a potassium formate desiccant solution using the thermal output from the micro-tubular SOFC in the first of its kind tri-generation system. The thesis has established that a clear operational advantage of the novel SOFC liquid desiccant tri-generation system is the potential for nonsynchronous operation. The constant SOFC thermal output can be used to re-concentrate the desiccant solution as a form of thermal energy storage. Unlike thermal storage techniques based on sensible energy, a significant advantage of (chemical) thermal energy storage in the form of strong desiccant solution is that there are minimal losses over time. Using this nonsynchronous operating concept, the experimental system can generate an increased peak cooling output of up to 527W and a daily tri-generation efficiency of 38%. An economic assessment demonstrates questionable performance; however this is anticipated to improve with SOFC capital cost reductions. Environmental assessments establish that emission reductions of up to 51% compared to a base case system are possible, with the potential for zero carbon operation with the transition to a pure hydrogen fuel. The thesis presents the following general conclusions with respect to the novel SOFC liquid desiccant tri-generation system: (1) SOFC and liquid desiccant air conditioning are an effective technological pairing. High tri-generation efficiencies, particularly in hot and humid climates, are demonstrated; (2) appropriate matching of component capacity is necessary. Overall tri-generation system performance is more influenced by the SOFC component than the liquid desiccant; and (3) it is primarily the optimisation of the liquid desiccant component that facilitates effective tri-generation system integration and operation. The thesis proposes that future work should focus on improving the thermal agreement between the SOFC and liquid desiccant component, accompanied by field trial testing in a building context.
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Jefferies, Carol. "Modelling a novel, thin strip, continuous steel caster delivery system." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28788.
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Smooth delivery of molten metal to a chilled substrate is a key prerequisite for the development of a successful technique for thin-strip casting steel. In this work, a numerical model of a thin-strip, liquid steel delivery system was developed, validated, and used to make design predictions. The proposed slot-type planar-flow delivery system could contain a porous flow modifier, and features an extended-pool metal delivery system to the chilled substrate.The steady-state, computational-fluid-dynamic (C. F. D.) model developed for this research is two-dimensional, and uses the finite-difference, control-volume formulation. The implicit solutions for the fluid flow and energy fields are fully coupled and include treatment of the solidification phenomena using the enthalpy-porosity approach. The model includes porous flow modifying regions within the delivery zone. These are treated as regions of complex media and make use of the "Brinkman-Forchheimer extended-Darcy" model. Turbulence was modelled using an ad hoc approach for both effective viscosity and effective thermal conductivity.
Numerical predictions of fluid flow were compared with experimental flow measurements and flow visualization using a water model of the proposed delivery system. The experiments confirmed that the flow modifiers had a very beneficial smoothing effect on fluid delivery to the substrate in the feeding system. The numerical predictions were in good agreement with the experimental results. As well, numerical predictions of shell thickness were compared with several different simple semi-analytical test cases.
The model was used for several parametric studies. The effect of flow modification, in conjunction with varying pool lengths, was studied. The model predicted that the presence of the flow modifiers would smooth the fluid flow to the substrate, and promote even extraction of heat, despite extension of the reservoir's length. Extending the pool length delayed the onset of solidification. Another study made predictions for cases with differing inlet and substrate boundary conditions, as well as for different exit gap sizes. This part of the work demonstrated the type of predictions possible with this model for use in the design of a prototype of the proposed delivery system.
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Floyd, Tamara M. (Tamara Michelle) 1974. "A novel microchemical system for rapid liquid-liquid chemistry." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8273.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, February 2002.Includes bibliographical references (leaves 110-119).
Microchemical systems are sub-milliliter systems for chemical processes. They are constructed using microfabrication techniques originally developed for the fabrication of microelectronic circuits. The reduction in size, as compared to conventional systems, offers several advantages in improvement of heat and mass transfer and control of flow fields. In addition, microchemical systems are smaller, therefore inherently safer and capable of shorter thermal response times. The focus of this work has been a microchemical system with a multi-inlet contactor for liquid-liquid processes. The systems are fabricated using, primarily, silicon and glass in which feature sizes range from approximately 10 to 500 [mu]m. The multi-inlet contactor consists of 10 alternating inlets for two components. Fluids continuously enter the contactor, are focused by a converging channel, mix and react in a 50 m channel. The contactor is the central element in the microchemical system that also includes a parallel plate heat exchanger, infrared transmission detection capabilities and thin film metal temperature sensors. Quantitative data are obtained using on-chip optical detection methods, integrated thin film sensors, and off-chip pressure sensors. For microchemical systems, the length scales are short. Consequently, Reynolds numbers are small and the flow is laminar. When two or more streams are contacted in a homogeneous system, the flow is stable. The short length scales of the resulting lamellar stream enable rapid diffusion mixing for applications, such as kinetics studies or reaction-rate-limited operation of fast reactions.
(cont.) The mixing characteristics in the multi-inlet contactor are investigated through experiments and simulations. Without optimization, sub-second mixing times are achieved. By using experiments and simulations to gain a better understanding of diffusion mixing in the system, 99% mixing is achieved in less than 25 ms. Characterization of the microchemical system also includes determining the overall heat transfer coefficient for the parallel plate heat exchanger and demonstrating on-chip infrared transmission detection from 4000-1000 cm-1. Thus, these devices combine all the features necessary for kinetic studies, specifically control of residence time, control and monitoring of temperature, and concentration measurement by infrared spectroscopy. As a demonstration of microchemical systems as tools for kinetics studies, the microchemical mixer was used with in situ Fourier Transform infrared spectroscopy to monitor the alkaline hydrolysis of methyl formate. This reaction follows second order kinetics and is fast with a half life of 70 ms for the conditions used in this study. The rate constant that was extracted was in good agreement with the literature value. Moreover, in contrast to a previous study, no sample post processing was needed and the half-life of the reaction was reduced by an order of magnitude. Microchemical systems can also be useful tools in achieving and understanding heterogeneous fluid contacting. When an aqueous phase and organic phase are contacted in a 1:1 volumetric ratio, flow segregation can occur ...
by Tamara M. Floyd.
Ph.D.
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Tierno, Nicholas C. "LONGITUDINAL CONTROL OF A NOVEL AIRBORNE WIND ENERGY SYSTEM." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1308165209.
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Ball, Martin J. "Oxidation studies of a novel barrier polymer system." Thesis, Aston University, 1995. http://publications.aston.ac.uk/9789/.
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The thermal oxidation of two model compounds representing the aromatic polyamide, MXD6 (poly m-xylylene adipamide) have been investigated. The model compounds (having different chemical structures, viz, one corresponding to the aromatic part of the chain and the other to the aliphatic part), based on the structure of MXD6 were prepared and reactions with different concentrations of cobalt ions examined with the aim of identifying the role of the different structural components of MXD6 on the mechanism of oxidation. The study showed that cobalt, in the presence of sodium phosphite (which acts as an antioxidant for MXD6 and the model compounds), increases the oxidation of the model compounds. It is believed that the cobalt acts predominantly as a catalyst for the decomposition of hydroperoxides, formed during oxidation of the models in the melt phase, to free radical products and to a lesser extent as a catalyst for the initiation of the oxidation reaction by complex formation with the amide, which is more likely to take place in the solid phase. An oxidation cycle has been proposed consisting of two parts both of which will occur, to some extent under all conditions of oxidation (in the melt and in the solid phase), but their individual predominance must be determined by the prevailing oxygen pressure at the reaction site. The different aspects of this proposed mechanism were examined from extensive model compound studies, and the evidence based on the nature of product formation and the kinetics of these reactions. Main techniques used to compare the rates of oxidation and the study of kinetics included, oxygen absorption, FT-IR, UV and TGA. HPLC was used for product separation and identification.
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Larronde-Larretche, Mathieu. "Development of a novel membrane bioreactor for cost-effective wastewater treatment and microalgae harvesting." Thesis, University of Glasgow, 2018. http://theses.gla.ac.uk/30805/.
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The rapid depletion of fossil fuels has raised increasing attention worldwide, and initiated intensive research for sustainable alternatives for energy production. Among these, biodiesel from microalgae has appeared as one of the most promising candidate due to their ability to accumulate large amount of lipids. Indeed, microalgae can achieve a productivity up to 25 higher than other crop sources without need of cultivatable soil, therefore without competing with food production. In the meantime, microalgae have also shown promising results for the treatment of various kind of wastewaters. However, the cultivation of microalgae for energy production suffers from the large costs of harvesting and dewatering of biomass, prior to lipid extraction and biofuel production, which accounts for up to 50% of operating costs. Therefore, the search for cost-effective methods of harvesting and dewatering of microalgae biomass has become necessary to optimize their usage. This study investigates forward osmosis (FO) for the dewatering of microalgae biomass and its implementation within a photobioreactor used for wastewater treatment. FO is a cost-effective filtration process based on the differences of osmotic pressure across a semi-permeable membrane. The use of FO for microalgae dewatering is of high interest, given the high fouling ability of microalgae biomass and the low fouling promises of FO. First, the feasibility of using FO for microalgae dewatering was assessed, focusing on better understanding the fouling mechanisms involved. The filtration performances have been investigated under various operating parameters. It has been found that when Ca2+-containing draw solutions were used, microalgae responded to the back diffusion of calcium ions by an extensive excretion of carbohydrates, accelerating the formation of algal flocs, thus enhancing the rate and extent of flux decline and reducing the algae dewatering efficiency. However, most of the fouling was reversible by simple hydraulic flushing. In addition, substantial adsorption of algal biomass was observed on the feed spacer. Also, Scenedesmus obliquus and Chlamydomonas reinhardtii, with fructose and abundant glucose and mannose in its cell wall, showed strong response to the back diffusion of calcium ions which encouraged S. obliquus to produce more extracellular carbohydrates and formed a stable gel network between algal biomass and extracellular carbohydrates, leading to algae aggregation and severe loss in both water flux and algae biomass during FO dewatering with Ca2+-containing draw solution. Among the species investigated, Chlorella vulgaris without fructose was the most suitable microalgae species to be dewatered by FO with a high algae recovery and negligible flux decline regardless of which draw solution was applied. These findings improve mechanical understanding of FO membrane fouling by microalgae; have significant implications for the algae species selection; and are critical for the development and optimization of FO dewatering processes. Finally, the implementation of FO dewatering with continuous microalgae biomass production and synthetic wastewater treatment was investigated. Two systems (External FO ; Immersed FO) have been studied and compared in order to provide insights on the advantages and disadvantages of each system. Constant parameters have been set identical for both systems: operation time; photobioreactor; hydraulic retention time; biomass production; FO permeate volume. The results reveals that the wastewater treatment efficiency (nutrients removal), as well as the production of biomass were greater with the immersed system due to a greater microalgae growth. However, these may not be sustainable in a long term operation of the immersed system. The external FO system was found better in terms of salinity build-up and FO dewatering performances. Overall, an external FO dewatering is recommended due to its better flexibility and sustainability.
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Chan, Yau Chung John. "A novel electric power quality monitoring system for transient analysis." Thesis, City University London, 2014. http://openaccess.city.ac.uk/5911/.
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Electricity is vital for our daily life in modern cites. In order to ensure its reliability and supply, an electric power monitoring system is indispensable in an electric power system. Currently, most electric power monitoring systems are designed for steady-state monitoring only. They may not be able to monitor instantaneous power disturbances, such as voltage surge, happened in electric power systems. In fact, instantaneous power disturbances are frequently found in electric power systems, which result in equipment failures and cause financial losses. Therefore, a novel electric power monitoring system is proposed in this thesis. Besides traditional functions, the proposed system is capable of monitoring and analyzing instantaneous power disturbances in electric power systems. Novelties of the proposed monitoring system are in the following three major aspects. Firstly, the proposed system is capable of monitoring instantaneous power disturbances. Unlike traditional monitoring systems, the proposed system captures not only statistical power quantities (e.g. kW, kWh), but also voltage and current waveforms. Since a considerable communication network bandwidth is required to transmit electric waveforms in a remote monitoring system, a novel waveform compression algorithm is proposed to realize real-time electric power waveform monitoring on low-speed communication networks (e.g. Zigbee). Secondly, the proposed system is capable of identifying various kinds of power disturbances automatically. It relieves electrical engineers from manned disturbance identification on preserved waveforms. Unlike traditional disturbance identification algorithms, the proposed system can identify not only voltage disturbances, but also current disturbances. Hence, it can provide a better chance in identifying more problems and disturbances in electric power systems. Thirdly, a novel time-frequency analysis method is proposed to analyze preserved waveforms. The proposed method is an improvement to the well-known Discrete Wavelet Packet Transform (DWPT). DWPT has been used by researchers and engineers to analyze disturbances and harmonics in electric power systems. However, DWPT is subjected to a non-uniform leakage problem, which has been discussed intensively in many studies. In order to tackle this issue, a frequency shifting scheme is introduced in the proposed method. A prototype has been implemented to demonstrate the feasibility of the proposed electric power monitoring system. There are two major components – a prototype meter and a central monitoring system. The performance of the prototype has been evaluated by conducting experiments and field tests. The capability of the proposed system for realtime remote monitoring has been verified on Zigbee network, which is a low-power, low speed wireless communication network.
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Shafieian, Dastjerdi Abdellah. "A solar‐driven membrane‐based water desalination/purification system." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2020. https://ro.ecu.edu.au/theses/2323.
Full textAbstract:
Lack of fresh water has turned into one of the major challenges of the world in the present century. Desalination of brackish or seawater has been proven to be one of the best solutions to cope with this global challenge. Among all the desalination methods, Membrane Distillation (MD) is well known as a cost effective and profitable technology for treating saline water. However, higher energy consumption compared to other separation techniques has been reported as MD’s main drawback. That is why the application of solar energy to provide the thermal energy requirement of MD modules has been the focal point of research in this field in recent years. Despite many studies and efforts that have been conducted to date, solar driven membrane based
systems have still many undiscussed aspects. Integrating solar energy and membrane technology is not yet a straightforward matter and has many opportunities for technical and economic improvements. Utilizing new solar technologies, their combination with thermal driven membrane modules, and trying to improve thermal and overall efficiency of this integration can be the bedrock of novel researches. Furthermore, most of the previous studies and research activities have been focused on desalination systems, while the proposed systems have been either inefficient or energy intensive, and other sources for improving water quality such as wastewater is completely under-researched. That is why, this study proposed a novel integrated solar membrane-based desalination and wastewater treatment system taking advantage of technologies such as heat pipes, vacuum tubes, and direct contact membrane distillation (DCMD) modules.
A theoretical study was considered to firstly investigate the performance and feasibility of the proposed system and secondly to obtain the optimum physical and operational characteristics of both solar and desalination systems. The theoretical analysis was performed by using appropriate energy and exergy equations which were solved in Matlab software. Heat and mass transfer equations along with energy and mass balance equations were considered in this study. A new multi-step theoretical approach was proposed and developed to model the DCMD unit, while the thermal resistance network method was applied in the simulation of the solar system including vacuum glasses, heat pipes, and manifold.
Based on the optimum data obtained from the mathematical models, an experimental rig was designed, manufactured, and tested under different climatic and operational conditions. The system was controlled using a central control unit including a control unit, a National Instrument Data Acquisition (NI-DAQ) system, and a power unit. An application program interface (API) was programmed in the LabVIEW 2014 software to record the data at 10- second intervals. Climatic data including solar radiation, ambient temperature, and wind velocity were collected from the weather station located at Edith Cowan University, Joondalup Campus which is located 23 km north of Perth business district.
The comparison of the theoretical and experimental results revealed the capability of the developed model to accurately predict the performance of the proposed system. In addition, the optimum characteristics of the system, including the optimum solar collector’s surface area, feed and permeate streams mass flow rates and temperatures, were determined. The results revealed that the application of this nanofluid as the solar working fluid along with implementing a variable mass flow rate technique significantly improved the overall efficiency of the solar system. Sodium Dodecyl BenzeneSulfonate (SDBS) at 0.1 wt.% was the optimum concentration of SDBS for 0.05 wt.% Al2O3/DI water nanofluid exhibiting the highest stability and thermal conductivity enhancement. The results also showed the high dependency of the DCMD module to the physical (e.g., length) and operational (e.g., feed and permeate mass flow rates) parameters, while its performance was independent of salinity. The highest freshwater production rates in hot and cold seasons were observed to be 3.81 and 2.1 L/m2h, respectively. Moreover, the maximum gained output ratios of the system were around 0.79 and 0.58 in hot and cold seasons, respectively.
The results also indicated that the gained output ratio and overall efficiency of the system improved upon application of a cooling unit in the permeate flow loop of the system, indicating the effectiveness of the proposed configuration. In addition, the freshwater production increased up to 37% when the system was equipped with a cooling unit. However, the economic feasibility of implementing the cooling unit needs further investigations. Moreover, the proposed system effectively removed the contaminating metals from wastewater by showing the removal percentage of 96, 89, 96, 100, 100, and 94% for Fe, Mn, Cu, Na, K, and Ca, respectively.
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Ning, Dawei. "A novel wireless based architecture for museums." Thesis, University of Ottawa (Canada), 2006. http://hdl.handle.net/10393/27161.
Full textAbstract:
Wireless networks were first developed in the 1970s, and people's interest in them has been growing ever since. A broad range of differing capabilities is covered by wireless technologies and is oriented toward different uses and needs. In this thesis, we propose a novel application architecture based on wireless networks and designed for museums to allow visitors, especially group of visitors, to have an attractive tour experience. While current museum visiting's approaches are largely interactive but have a number of disadvantages, this application utilizes mobile devices as facilities to help visitors benefit not only from visiting a real museum environment but at the same time enriching their ability to search for additional material. Moreover, as it provides powerful functions, the application will enable visitors to establish a virtual community platform by which they will be able to communicate and share information through wireless networks.
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Yang, Shuming. "A novel chip interferometry system for online surface measurements." Thesis, University of Huddersfield, 2009. http://eprints.hud.ac.uk/id/eprint/6311/.
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This thesis documents the development of a novel chip interferometry system using advanced microtechnology and optical methodologies. This is the first time that this type of system has been reported in surface metrology. The system is designed to be compact, robust and stable even though it does not involve noise compensation and feedback control. Compared to currently available techniques, this system has great potential for on-line surface measurements. This application is based on a Michelson interferometer and wavelength scanning method. Considering the fabrication capability and effective cost, the system consists of two parts, an optical chip and an optical probe. The optical chip is the main focus of this research and it integrates a tuneable laser, a directional coupler, an optical isolator and a photodetector. The research approach for the optical chip is to use a planar silica motherboard for the passive circuitry onto which are assembled silicon daughterboards containing the different chip components that are to be integrated. The theory, methodology and technique for these individual chip components are explored. The optical probe is used to collimate, diffract and focus the light beam for surface scanning. The individual chip components and the optical probe are applied to build an experimental interferometry system. Initial surface measurements by this system have been carried out. The experimental results provide substantive evidence that the chip interferometry system is feasible for on-line surface measurements.
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Newman, Stephen. "The discovery and development of a novel photosolubilisation system." Thesis, University of East Anglia, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280998.
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Keon, Neil. "Simulation of the proton exchange membrane fuel cell: Dynamic modelling and an environment." Thesis, University of Ottawa (Canada), 1995. http://hdl.handle.net/10393/9667.
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The proton exchange membrane fuel cell (PEMFC) is the focus of modeling and simulation efforts in order to better understand this technology and improve its design and operation. Simulated polarization curves for PEMFCs duplicate the observed performance of PEMFCs with varying degrees of success. In order for modelling and simulation to be more widely used in this field and elsewhere, effective tools must be made available for non-programmers to apply their knowledge to simulation problems. GestCell (A modelling and simulation environment based on Gest) is a new modelling and simulation environment designed with non-programmers in mind, in particular scientists studying PEMFCs. A friendly graphical interface allows users who are knowledgeable in a non-programming field to enter information about a system into GestCell, which automatically constructs a Gest specification. The Gest specification is highly readable for the user, and the system is able to generate a C++ program with the specification in order to allow the user to carry out simulation with the model, with very little knowledge in the area of simulation. GestCell is very general in nature and could be used in a wide variety of fields. It has a great deal of potential to be a powerful modelling and simulation environment.
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Peng, Hui. "The treatment of bilge water using a MF/UF hybrid membrane system: Membrane fouling, cleaning and the effect of constituents on flux decline." Thesis, University of Ottawa (Canada), 2002. http://hdl.handle.net/10393/6110.
Full textAbstract:
Bilge water accumulates in recesses and bilges onboard ships. Depending on the type of design and age, ships can generate large volumes of bilge water. This wastewater is a mixture of fresh water and seawater containing various contaminants. Typical contaminants may include fuels, oils, greases, detergents, solvents, rusts, paints, insulation material and a wide variety of other substances. Bilge water is a very challenging wastewater to treat due to large variations in production rates and the complex nature of the wastes in solution. Membrane based Oily Water Separators (OWS) are being increasingly used throughout the world for the treatment of oily wastewater. This work focused on two areas of study: (1) Effects of selected components found in bilge water on membrane performance, and (2) Pilot scale testing using a Microfiltration/Ultrafiltration (MF/UF) hybrid system. The studies are aimed at determining suitable membrane materials and optimum operating conditions such as trans-membrane pressure (TMP) and backflushing for permeate flux enhancement. (Abstract shortened by UMI.)
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Aw, Eng Sew 1978. "Novel monitoring system to diagnose rail track foundation problems." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/30044.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2004.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 175-177).
A low cost, remote monitoring system has been developed to diagnose rail track subgrade failures. The portable monitoring system consists of five liquid vertical settlement probes, one piezometer, a small data acquisition system and laptop, and an Internet communication with remote control capabilities. The probes are designed to be small, easily installed (within railbeds using a one-man auger), easily manufactured, and low cost. The sensors and data acquisition have been rigorously tested and calibrated in the laboratory. The settlement probes and piezometer are sensitive to changes in the atmospheric pressure and temperature, and calibration curves have been obtained to correct for these effects. The settlement probes are further subjected to silicone oil density changes due to differential temperature between the atmosphere and the ground, and these effects are minimised by a proposed correction method. The prototype monitoring system was installed through a two phase installation exercise at the bridge approach site in FAST (Facility for Accelerated Service Testing) at Transportation Technology Centre Inc (TTCI), Pueblo, Colorado, USA. Since there are virtually no settlements at the stiff, sandy bridge approach site, the sensors are evaluated for ideal stability and robustness while being subjected to well-defined Heavy Axle Train (HAL) loadings. A detailed evaluation of the prototype system found that probes installed at depths 1.0 to 1.5m within the subgrade did not achieve satisfactory measurement stability (i.e. measurements have a spurious drift), due principally to manufacturing defects. The prototype probes were sufficiently robust to survive installation within the subgrade but not within the ballast itself.
(cont.) The probe designs have subsequently been refined to eliminate sources of drift, and have undergone more extensive calibration to account for differential temperature effects. These second generation probes are scheduled for field deployment as part of the on-going research.
by Aw, Eng Sew.
S.M.
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Bhathena, Jasmine. "A novel oral polymeric membrane Lactobacillus formulation for amelioration of Non-Alcoholic Fatty Liver Disease and associated disorders." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103524.
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Non-alcoholic fatty liver disease (NAFLD) is a leading cause of progressive liver damage. It is commonly associated with conditions such as obesity, diabetes or dyslipidemia. Currently, there are no therapeutic interventions for this potentially serious disorder. The foremost challenge is to decrease liver fat and progression toward steatohepatitis and fibrosis, and the subsequent risk of cirrhosis. In this thesis, a treatment modality for use in NAFLD is investigated. Specifically, this thesis aims to develop an oral microencapsulated feruloyl esterase active probiotic bacterial cell formulation for amelioration of NAFLD and the associated cluster of diseases. The formation and preparation of alginate-poly-L-lysine-alginate (APA) microencapsulated lactobacilli was established and optimized. The feruloyl esterase activity, yield of generated ferulic acid, gastrointestinal viability and stability of APA microencapsulated lactobacilli was determined in vitro in flasks as well as in a computer controlled simulated dynamic gastrointestinal tract model. Microencapsulated Lactobacillus fermentum 11976 feruloyl esterase active cells were found to be most suitable for use in real time analysis for oral therapeutic applications. Results also show that in-vivo, a high fat high cholesterol diet successfully induced NAFLD in a novel hamster model along with central obesity, insulin resistance, and dyslipidemia. Treatment of NAFLD afflicted hamsters with microencapsulated Lactobacillus fermentum 11976 probiotic formulation, in contrast to control untreated hamsters, showed significant reduction in the risk of a coronary event and progression of atherosclerotic plaque formation, reduced hepatic fat deposition and normalization of key liver damage enzymes (e.g. Alanine transaminase [ALT], Gamma-glutamyl transferase [GGT]). In addition, insulin resistance and central obesity was reduced, better glycemic control was achieved, and progression of various other parameters of pathological event to severe forms of NAFLD was attenuated. We also elucidated the mechanisms by which this formulation asserts its beneficial effect. This work indicates the immense potential of the novel microencapsulated Lactobacillus fermentum 11976 probiotic formulation as an orally delivered therapy for NAFLD and other associated diseases. Further studies will investigate its full potential as a therapeutic option in human populations.La stéatose non alcoolique (NAFLD) est souvent trouvée chez les patients atteintes de l'obésité, du diabète ou de la dyslipidémie. Actuellement, il n'y a aucune intervention thérapeutique pour traité ce désordre potentiellement sérieux. Le premier défi est de diminuer la graisse dans le foie et alors la progression vers le steatohepatitis et la fibrose, et le risque suivant de cirrhose. Cette thèse a pour but d'étudier et développer une modalité de traitement pour l'usage dans NAFLD. Spécifiquement, cette thèse vise à développer une formulation orale qui contient de cellules bactériennes probiotique micro-encapsulée. Ces bactéries possèdent une estérase de feruloyl active qui a pour but, l'amélioration de NAFLD et le faisceau associé des maladies. La formation et la préparation des lactobacilles micro-encapsulés dans l'alginate-poly-L-lysine-alginate (APA) ont été établies et optimisées. L'activité d'estérase de feruloyl, le rendement d'acide férulique produit, la viabilité gastro-intestinale et la stabilité des lactobacilles micro-encapsulés d'APA ont été déterminés in vitro dans des flacons aussi bien que dans un modèle gastro-intestinal dynamique, simulé et contrôlé par ordinateur. Les cellules Lactobacillus fermentum 11976 actives d'estérase de feruloyl micro-encapsulé se sont avérés le plus approprié pour l'analyse en temps réel que pour des applications thérapeutiques orales. Les résultats in vivo montrent que dans notre modèle original de hamster, un régime riche en cholestérol et à haute teneur de graisses induit NAFLD, l'obésité centrale, la résistance d'insuline, et la dyslipidémie. Le traitement avec la formulation probiotique Lactobacillus fermentum 11976 micro-encapsulés a été administré aux hamsters atteintes de NAFLD. En comparaison avec les hamsters non traités, le traitement a révélé la diminution de plusieurs indicateurs comme les suivantes : risque d'un événement coronaire, la formation de plaques athérosclérotique, l'accumulation de gras hépatique. Aussi, les enzymes associés au foie endommagée, plus spécifiquement, la transaminase d'alanine [ALT], la transférase de Gamma-glutamyle [GGT]) sont revenu aux niveaux plus normales. En outre, la résistance d'insuline et l'obésité centrale ont été réduites, une meilleure commande glycémique a été réalisée, et la progression de divers autres paramètres d'événement pathologique aux formes graves de NAFLD ont été atténuée. Élucidation des mécanismes par lesquels cette formulation affirme son effet bénéfique est proposé. Ce travail indique l'immense potentiel de la formulation probiotique orale du Lactobacillus fermentum 11976 micro-encapsulés comme thérapie pour NAFLD et autres maladies associées. D'autres études poursuivront pour déterminer la capacité de ce traitement comme option thérapeutique dans la population humaine.
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Davies, Neale. "Novel, induced flow, centrifugal water pumping system for off grid application." Thesis, University of Liverpool, 2015. http://livrepository.liverpool.ac.uk/2037461/.
Full textAbstract:
Water provision in rural areas represents a significant challenge, especially within the context of resource and sanitation in developing countries. High set-up costs, lack of installation expertise and reliability issues, arising from fluctuating operational conditions, have prevented many people from receiving the full benefit of automated pumping systems. The specific aim of this thesis is to assess the feasibility of using a tunable, induced flow subsystem as a means of optimising the power utilization and performance of a centrifugal pump over a wider range of operating conditions than typically expected. More generally, the research presented is undertaken to reduce the high implementation costs and localised limitations of rural water pumps by developing the theory towards a ‘’one-size-fits-all’’ pumping system. The theoretical analysis of an induced flow centrifugal pumping system is presented, coupled with the analogous electrical system. The results of simulations performed using both systems are compared to experimental results, obtained using an induced flow subsystem (IFS) test rig constructed at the University of Liverpool. All sets of results demonstrate consistent IFS characteristics, identifying its capability to maintain maximum power point (MPP) operation of the centrifugal pump irrespective of load. Further, the experimental results reveal a boost in output pressure which enables the pump to achieve an improved hydraulic power and increased operating range over the same system without an IFS. It is concluded that, through the addition of an IFS, the performance of a centrifugal pump may be decoupled from its operating head, expanding its range of serviceable conditions and demonstrating potential to develop a ‘’one-size-fits-all’’ system. Ultimately, this could offer a cheaper and more reliable supply of a resource which is vital to life in any rural location: clean water.
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Cimenler, Ummuhan. "Molecular-Size Selective Zeolite Membrane Encapsulated Novel Catalysts for Enhanced Biomass to Liquid (BTL) Processes." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6644.
Full textAbstract:
80% of energy usage in the word comes from fossil fuels (coal, oil, natural gas) and among the fossil fuels, oil is the most consumed energy source especially in transportation. However, due to concerns about energy demand and energy sustainability, global warming and dependency on foreign oil, generation of renewable fuels is crucial for transportation. Biomass to Liquid (BTL) is a promising process available to produce renewable liquid fuels. BTL fuels have great potential to meet the growing demand for liquid fuels, mitigating climate change, and providing value to rural areas. However, there are two major challenges with biofuels produced from BTL. One of the major challenge is the H2:CO ratio of biomass gasification product is insufficient for production of hydrocarbon fuels due to formation of methane and tars. The steam reforming of hydrocarbons, to improve the H2:CO ratio, is generally conducted as part of the gas conditioning. However, tars cause the catalysts to deactivate rapidly. Secondly, for fuels produced from the gasification route regardless of feedstock source, there is an economy-of-scale issue. Therefore, it is desirable to seek ways of process intensification to allow small scale plants to be more economical. Zeolites can be used to solve these challenges since they have reactant selectivity property.
To achieve a catalyst capable of reforming methane without potential for deactivation by tars, the encapsulation of a core reforming catalyst with porous zeolite shell is examined in this dissertation. After detailed introduction in the first chapter, a composite H-β zeolite membrane encapsulated 1.6wt%Ni/1.2wt%Mg/Ce0.6Zr0.4O2 steam reforming catalyst was prepared by a physical coating method in the second chapter of the study. Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) analyses indicated that H-β zeolite was coated successfully on the core reforming catalyst. The pore size of H-β zeolite shell was between 0.43 and 0.57 nm, as measured by the HK method. Steam reforming of CH4 and C7H8 (as a tar model) were conducted with the composite H-β zeolite coated reforming catalyst, the two components individually, and physical mixtures of the two components as a function of temperature (780–840°C). CH4 conversion was enhanced by a factor of 2–3 (depending on temperature) for the composite catalyst as compared to the core reforming catalyst individually even though the zeolite did not have any activity alone. Possible reasons for the enhanced CH4 conversion include confined reaction effects (increase residence time within pores) of the catalyst containing the zeolite coating and/or Al3+ promotion of the active sites. Alternatively, due to molecular-size selectivity, the composite H-β zeolite coated reforming catalyst demonstrated a decrease in C7H8 conversion when compared to the uncoated reforming catalyst. The results validate the use of size selective catalysts to control molecular traffic and enhance the reforming reactant selectivity.
A composite catalyst consisting of an outer layer of zeolite membrane encapsulating an inner reforming catalyst core was synthesized by a double physical coating method to investigate reactant selectivity (ratio of methane/toluene conversion rate) in steam reforming of methane (CH4) and toluene (C7H8). A double encapsulation (51 wt % H-β zeolite) of a 1.6 wt % Ni−1.2 wt % Mg/Ce0.6Zr0.4O2 steam reforming catalyst was compared to a singly coated composite catalyst (34.3 wt % H-β zeolite) to investigate zeolite thickness effects on the conversion of different sized hydrocarbons. The increase in the zeolite content from 34.3 to 51 wt % decreased both CH4 and C7H8 conversions (by up to 14% depending upon the temperature) as a result of the increase in diffusional limitations. Weisz−Prater criteria and Thiele moduli calculations confirmed that the reactions were performed under internal diffusion limitations. The C7H8 conversion of the 51 wt % composite (SR@β51%) catalyst was similar to the zeolite alone, indicating negligible contribution from the protected catalyst core. The reactant selectivity increased by up to 1.5 times on SR@β51% in comparison to the SR@β34.3% composite. Combined reforming at 800 °C on the SR@β51% catalyst indicated that the catalyst was stable during the 10 h time on stream.
Continuing this work, a non-acidic Silicalite-1 zeolite membrane encapsulated 1.6wt%Ni-1.2wt%Mg/Ce0.6Zr0.4O2 steam reforming composite catalyst, synthesized by a physical coating method, was used to investigate effect of encapsulation on size selective steam reforming, using methane (CH4) and toluene (C7H8) as representative species. Weisz-Prater Criteria and Thiele moduli calculations indicated internal diffusion limitations. Combined reforming of CH4 and C7H8 at 800°C on the composite catalyst demonstrated stability during the 10 h time on stream while uncoated SR catalyst deactivated. The non-acidic Silicalite-1 encapsulated catalyst showed decreases (~2-7%) in both CH4 and C7H8 conversions compared to acidic H-β zeolite confirming that shell acidity did contribute to conversion and suggesting that shell defects/grain boundaries were responsible for the C7H8 conversion.
Finally, low temperature 0.16wt%Pt–1.34wt%Ni–1.00wt%Mg/(Ce0.6Zr0.4)O2 reforming catalyst was triple coated with H-β zeolite (60 wt% of zeolite) to be utilized synthesis of combination steam reforming catalyst (SR) and Fischer-Tropsch Synthesis (FTS) catalyst (CRAFT) for a single-step conversion of methane to liquid fuels. Scanning electron microscopy (SEM) image and energy-dispersive spectroscopy (EDS) analysis result demonstrated that H-β zeolite was successfully encapsulated onto the low temperature reforming catalyst. The catalyst was tested in steam reforming of methane (CH4) and toluene (C7H8) and the results was compared with 51 wt%. While CH4 conversions are very similar on the 60wt% composite catalyst with 51wt% composite catalyst, no C7H8 conversion was seen on the 60 wt% composite catalyst. Thus, it is concluded that the 60 wt% composite catalyst can be utilized to synthesis CRAFT catalyst.
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Stone, Erica. "Development of a Novel Membrane Process for the Immediate Production of Drinking Water from Varying Quality Aqueous Sources." Honors in the Major Thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1002.
Full textAbstract:
This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.Bachelors
Engineering and Computer Science
Environmental Engineering
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Foley, Brian S. B. (Brian M. ). Massachusetts Institute of Technology. "Solar thermal collector system modeling and testing for novel solar cooker." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92179.
Full textAbstract:
Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (page 22).
Solar cookers are aimed at reducing pollution and desertification in the developing world. However, they are often disregarded as they do not give users the ability to cook after daylight hours. The Wilson solar cooker is a solar cooker designed to address this problem by converting solar energy and storing that energy as heat in the form of molten salt (lithium nitrate). This thesis involved research, modeling, and experimentation for the solar collection system of the cooker. This thesis looked at prior research on glazing, Fresnel lenses, and absorber surface treatments to identify and evaluate elements for use in the collection system. Borosilicate glass, with a thermal conductivity of 1.005 W/mK and a solar transmittance of 0.91, and flat black paint, with absorptivity 0.96 and emissivity 0.88 were identified as potential elements for use in first trials. Experimentation was performed on copper and aluminum samples with various surface treatments powered by various Fresnel lenses to evaluate the relative efficiency of these treatments. A novel treatment method, machining a conical hole into the sample, was found to improve efficiency on untreated samples, but inferior to flat black paint. Modeling predicted that the minimum collection area for an acrylic Fresnel lens off-number 1.2 was 0.60 m² for and 0.65 m² for the proposed collector without and with glazing, respectively. A recommendation of collection area 1 m² was proposed to account for unexpected losses due to manufacturing errors, positioning errors, and environmental variation. This thesis also analyzed a proposal for a novel solar collector, a polished aluminum cone. Modeling and efficiency testing showed the cone to be inadequate for the radiation collection needed for the solar cooker.
by Brian Foley.
S.B.
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Bonner, Ross A. (Ross Anthony). "Design and development of a novel liquid desiccant air-conditioning system." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/129027.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2020Cataloged from student-submitted PDF of thesis.
Includes bibliographical references (pages 105-108).
The Direct Evaporative Closed Air Loop (DECAL) system is a novel high efficiency liquid desiccant air-conditioning (LDAC) system which runs primarily on thermal energy rather than electricity. It is designed for residential cooling in hot and humid climates where demand is growing rapidly and incumbent direct-expansion system performance is poor. Unlike other LDAC systems, DECAL is modular. This allows the indoor hardware to remain small and non-intrusive, and offers increased flexibility to install the system in existing building stock without costly changes to the structure. This work lays out the basic operating cycle of the DECAL system and shows its thermodynamic merits in terms of ideal system performance against other LDAC systems. Design studies show DECAL offers improved thermal efficiency, especially in humid climates. The ideal thermal coefficient of performance (COP[subscript th]) is 1.24 at the design point ambient condition of 35C, 60% RH.
A mathematical model is built to better characterize performance and optimize the system design. With transport inefficiencies included, the optimal system electrical and thermal COP (COP[subscript e] and COP[subscript th]) are 46.3 and 0.759 respectively for a LiCl system at the design point. These results show the DECAL system could reduce electrical consumption by over 85% from present day best-in-class systems using low-grade thermal energy. A benchtop scaled test of the closed air loop is constructed to validate the model. Experimental test results agree well with the model predictions for evaporative cooling effectiveness and sensible heat exchange, as well as pressure drop. The drying effect of the LAMEE is lower than anticipated. This is likely due to crystallization of liquid desiccant in the pores of the membrane, resulting in a high vapor diffusion resistance. Adjusting for this effect, full system test measurements match the system model well.
The benchtop rig testing verified that the closed air loop is capable of generating a sensible cooling effect, but further testing is required to demonstrate modelled figures of merit are achievable.
by Ross A. Bonner.
S.M.
S.M. Massachusetts Institute of Technology, Department of Mechanical Engineering
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Meier, Stephan. "Novel voltage source converter based HVDC transmission system for offshore wind farms." Licentiate thesis, KTH, School of Electrical Engineering (EES), 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-568.
Full textAbstract:
Offshore wind farms have recently emerged as promising renewable energy sources. For increasing distances between offshore generation and onshore distribution grid, HVDC transmission systems based on voltage source converters can be a feasible and competitive solution. This thesis presents a comprehensive evaluation of a novel integrated wind farm topology that includes the generator drive system, the turbine interconnection and the HVDC transmission.
In the proposed concept, every wind turbine is connected to a single-phase medium-frequency collection grid via a distribution transformer and a cycloconverter, which allows the wind turbines to operate at variable speed. The collection grid is connected to an HVDC cable via a transmission transformer and a single-phase voltage source converter. This thesis evaluates in detail the principle of operation, which is also verified with system simulations in PSCAD.
The proposed concept promises several potential benefits. Converter switching losses and stress on the semiconductors for example can be considerably reduced by applying a soft-switched commutation scheme in all points of operation. Single-phase medium-frequency transformers have comparably low losses and their compact size and low weight implies an important benefit in an offshore environment. In addition, the voltage source converter is considerably simplified by the reduction to one phase leg, which implies a substantial cost saving.
Several technical challenges are identified and critically evaluated in order to guarantee the feasibility of the proposed concept. Especially the design of the medium-frequency collection grid is crucial as unwanted system resonances can cause dangerous overvoltages. Most of the technical challenges concern the specific characteristics of the proposed concept. The insulation of the single-phase medium-frequency transformers for example needs to withstand the high voltage derivatives. This thesis contains also considerations regarding the dimensioning and optimization of different system components.
A survey of different transmission systems for the grid connection of wind farms shows the potential of the proposed concept, which addresses several problems associated with electrical systems of wind farms. Both the requirements for variable-speed operation of the wind turbines and an interface for HVDC transmission are fulfilled in a cost-effective way. Compared to conventional voltage source converter based HVDC transmission systems, the initial costs are reduced and the expected annual energy production is increased. In addition, the proposed voltage source converter based HVDC transmission system can fully comply with recent requirements regarding the grid connection of wind farms.
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Cheng, Sheng. "Novel implementation technique for a wavelet-based broadband signal detection system." Thesis, University of Warwick, 2010. http://wrap.warwick.ac.uk/4515/.
Full textAbstract:
This thesis reports on the design, simulation and implementation of a novel Implementation for a Wavelet-based Broadband Signal Detection System. There is a strong interest in methods of increasing the resolution of sonar systems for the detection of targets at sea. A novel implementation of a wideband active sonar signal detection system is proposed in this project. In the system the Continuous Wavelet Transform is used for target motion estimation and an Adaptive-Network-based Fuzzy inference System (ANFIS) is adopted to minimize the noise effect on target detection. A local optimum search algorithm is introduced in this project to reduce the computation load of the Continuous Wavelet Transform and make it suitable for practical applications. The proposed system is realized on a Xilinx University Program Virtex-II Pro Development System which contains a Virtex II pro XC2VP30 FPGA chip with 2 powerPC 405 cores. Testing for single target detection and multiple target detection shows the proposed system is able to accurately locate targets under reverberation-limited underwater environment with a Signal-Noise-Ratio of up to -30db, with location error less than 10 meters and velocity estimation error less than 1 knot. In the proposed system the combination of CWT and local optimum search algorithm significantly saves the computation time for CWT and make it more practical to real applications. Also the implementation of ANFIS on the FPGA board indicates in the future a real-time ANFIS operation with VLSI implementation would be possible.
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Lycksam, Andreas, and Martin Andersson. "Development of a novel test system for the ATLAS-upgrade at CERN." Thesis, Uppsala universitet, Högenergifysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-353803.
Full textAbstract:
The ATLAS-upgrade is a project with the endeavors to enhance the performance of the ATLAS detector located at CERN. The intention of this project is to enable testing of the upgraded components locally at Ångströmlaboratoriet, Uppsala University, in cooperation with CERN. A power supply system was constructed to provide the correct voltage to the new electronic hybrid circuits. The hybrids need to be tested under the right conditions hence governing the features of the system. A graphical user interface with included software that controls and monitors the hardware in the system was developed. To ease connection of the test system, a backplane power circuit board was designed for the power supply cards.ATLAS-upgrade experiment
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Linga, Srujan. "A novel positioning system for accurate tracking in indoor environments." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40530.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.Includes bibliographical references (p. 91-93).
Precise positioning is crucial to many applications involving autonomous robots in indoor environments. Current solutions to the indoor localization problem are either both highly unreliable and inaccurate (like GPS based systems), or hugely expensive (such as the iGPS system). In this thesis we propose, design and build a low-cost, robust and highly accurate indoor localization system using laser light sources. The system is composed of three transmitting laser modules arranged in a straight line and a receiver module mounted on the mobile robot. The system calculates the coordinates of the mobile robot by using triangulation algorithms which require precisely measured values of the angles of the receiver with respect to the three laser emitters. Results from practical testing of the system in an aircraft wing assembly set-up have been found to be extremely encouraging. Using our system, the mobile robotic arm could be localized accurately within error margins defined approximately by Gaussian distributions centered at the object's true coordinate values and with standard deviations of 0.1778 mm, 0.1016 mm and 0.3352 mm in the x, y and z coordinate directions respectively. The system is also used to detect height drop in the arm due to its weight as it extends to perform fitting operations on the skin of the wing. Feedback from the laser localization system is used to adjust the position of the tip of the robotic arm in order to perform a sequence of high precision docking tasks within the aircraft wing.
by Srujan Linga.
S.M.
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Zhou, Mo S. M. Massachusetts Institute of Technology. "Simulation of a novel multiprocessor system based on dataflow principles." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/106071.
Full textAbstract:
Thesis: S.M. in Computer Science and Engineering, Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 53-54).
This thesis research is a study of a novel processor architecture for a massively parallel computer system. An existing simulation of the Fresh Breeze architecture has been extended to incorporate a multi-level memory hierarchy and dynamic load balancing. An efficient hardware-based garbage collection mechanism has been proposed. Various design trade-offs are evaluated. The simulation demonstrates that the architecture can support memory access with DRAM latency and still achieve high processor utilization.
by Mo Zhou.
S.M. in Computer Science and Engineering
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Song, Jamie 1977. "Optimization of data acquisition system for novel DNA sequencing instrument." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/86500.
Full textAbstract:
Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.Includes bibliographical references (leaf 61).
by Jamie Song.
S.B.and M.Eng.
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Panda, Amayika. "A Novel Configurable Benchmarking System for Multi-core Architectures." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1300479983.
Full text
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King, Ryan N. (Ryan Nicholas). "Design of a novel six-axis metrology system for meso-scale nanopositioners." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/54500.
Full textAbstract:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 55).
The purpose of this research is to develop the best possible means and methods of building a six axis metrology system given cost and space constraints. Six axis measurements are a crucial part of precision engineering and characterizing machine performance, however commercially available sensors are not cost-efficient and are difficult to incorporate into meso-scale machines. The novel approach presented here uses three pairs of laser diodes and quadrant photodiodes to achieve six axis measurements. This paper presents a general parametric model that can predict the output of the photodiodes due to translations and rotations of the target for any geometry of the system. The device has performance characteristics of translational resolution in the range of microns depending on the geometry of the system, a bandwidth of 17.5 MHz, and dominant noise in the sensor of ±1.6 nm. This device will be useful in a variety of applications including nanomanufacturing, bio instrumentation, Dip Pen Nanolithography, AFM, and many more.
by Ryan N. King.
S.B.
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Gentile, Margaret H. "A novel personal cooling system for use by soldiers in hot climates." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/65301.
Full textAbstract:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 50).
CD-ROM contains multimedia supplemental material for thesis.
This report focuses on the design, testing and fabrication of a lightweight personal, portable cooling system for use by soldiers beneath their Interceptor body armor. An alpha prototype was constructed and was used to generate promising, quantitative results. This first level data was combined with an analysis of the strengths and weaknesses of the design to lay down the framework for the beta prototype which will be constructed at a later date. The military and physiological requirements for such a device are briefly discussed, as are concerns over fit, wearer comfort, product durability and ease of use.
by Margaret H. Gentile.
S.B.
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Zhang, Xingxing. "Investigation of a novel solar photovoltaic/loop-heat-pipe heat pump system." Thesis, University of Hull, 2014. http://hydra.hull.ac.uk/resources/hull:8422.
Full textAbstract:
With the widespread deployment of solar photovoltaic (PV) and thermal devices imminent, this research aims to resolve some engineering barriers to the existing solar photovoltaic/thermal (PV/T) technologies by incorporating an innovative loop heat pipe (LHP) and a typical heat pump. In addition, a coated aluminium-alloy (Al-alloy) sheet replaces the conventional baseboard for the PV cells to improve heat exportation. As a result, this research has developed a novel solar PV/LHP heat pump system to maximise the electrical output of a PV module and generate an additional amount of heat simultaneously. The overall investigation followed the basic methodology of combined theoretical and experimental analysis, including procedures for a critical literature review, optimal concept design, mathematical derivation, the development of simulation models, prototype fabrication, laboratory-controlled and field testing, simulation model validation and socio-economic analysis. A full range of specialised simulation models was developed to predict the system performance with reasonable accuracy. The proposed LHP device has a maximum heat transfer limit of about 900W. The Al-alloy baseboard improved PV efficiency by nearly 0.26% when compared with a traditional PV baseboard. During the real-time measurement conditions, the mean electrical, thermal and overall energetic/exergetic efficiencies of the PV/LHP module were 9.13%, 39.25% and 48.37%/15.02%, respectively. The basic thermal and advanced system coefficients of performance (COPth/COPPV/T) were almost 5.51 and 8.71, respectively. The test results indicated that this system performed better than conventional solar/air energy systems. The feasibility analysis illustrated that this system could generate a substantial amount of energy in subtropical climatic regions, such as Hong Kong. It is cost effective to operate this system in areas with high energy charging tariffs, such as London and Hong Kong. The research results are expected to configure feasible solutions for future PV/T technologies and develop a new solar-driven heating system. The core technologies may enable a significant reduction in or even elimination of the carbon footprint in the built environment.
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Lunka, Alex A. "Development of a Novel Air-to-Liquid Mass Transfer Mechanism." Ohio University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1415121834.
Full text
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Carradori, Dario. "Novel nanoparticle-based drug delivery system for neural stem cell targeting and differentiation." Thesis, Angers, 2017. http://www.theses.fr/2017ANGE0056/document.
Full textAbstract:
Les cellules souches neurales (CSNs) se situent dans des régions spécifiques du système nerveux central qui sont appelées niches. Ces cellules sont capables de se répliquer ou se différentier en cellules neurales spécialisées (neurones, astrocytes et oligodendrocytes). C’est grâce à cette propriété de différentiation que les CSNs sont étudiées comme thérapie chez les patients atteints d’une maladie neurodégénérative. En effet, elles pourraient remplacer les cellules neurales altérées et ainsi restaurer les fonctions neurologiques. De nombreuses approches ont été développées afin de stimuler la différentiation des CSNs, dont la plus prometteuse est la différentiation des cellules endogènes directement au sein de leurs niches. Actuellement, il n’existe pas de molécule active ou de système thérapeutique qui cible les CSNs endogènes et qui induit leur différentiation simultanément. Le but de ce travail est de fournir un système de délivrance de molécules bioactives capable de cibler les CSNs endogènes et d'induire leur différenciation in situ. Nous avons développé et caractérisé des nanoparticules lipidiques (LNC), un système de délivrance très versatile. NFL-TBS.40-63, un peptide ciblant les CSNs, a été adsorbé à la surface des LNC afin de les diriger contre les CSNs endogènes. Nous avons observé que ces NFL-LNC ne ciblaient que les CSNs du cerveau et pas de la moelle. Afin d’étudier les interactions spécifiques entre les nanoparticules et les CSNs, nous avons caractérisé et comparé les propriétés de leur membrane plasmique. Enfin, nous avons encapsulé de l’acide rétinoïque, une molécule connue pour stimuler la différentiation des CSNs, dans les LNC-NFL et étudié leur impact sur la différentiation de CSNs in vitro et in vivo. Ce travail contribue au développement de thérapies efficaces et sures pour le traitement de maladies neurodégénératives à travers la différentiation de CSNs endogènesNeural stem cells (NSCs) are located in specific regions of the central nervous system called niches. Those cells are able to self-renew and to differentiate into specialized neuronal cells (neurons, astrocytes and oligodendrocytes). Due to this differentiation property, NSCs are studied to replace neuronal cells and restore neurological functions in patients affected by neurodegenerative diseases. Several therapeutic approaches have been developed and endogenous NSC stimulation is one of the most promising. Currently, there is no active molecule or therapeutic system targeting endogenous CSNs and inducing their differentiation at the same time. The aim of the work was to provide a drug delivery system able both to target endogenous CSNs and to induce their differentiation in situ. Here, we developed and characterized lipidic nanoparticles (LNC) targeting endogenous NSCs. A peptide called NFL-TBS.40-63, known for its affinity towards NSCs, was adsorbed at the surface of LNC. We observed that NFL-LNC specifically targeted NSC from the brain and not from the spinal cord in vitro and in vivo. To explain this specificity, we characterized and compared NFL-LNC interactions with the plasmatic membrane of both cell types. Finally, we demonstrated that by loading retinoic acid in NFL-LNC we were able to induce brain NSC differentiation in vitro and in vivo. This work contributes to the development of efficient and safe therapies for the treatment of neurodegenerative disease via the differentiation of endogenous NSCs
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Freegah, Basim. "Design, development and optimisation of a novel thermo-syphon system for domestic applications." Thesis, University of Huddersfield, 2016. http://eprints.hud.ac.uk/id/eprint/31172/.
Full textAbstract:
In order to decrease reliance on fossil fuels, renewable energy has become an important topic of research in recent years. The development in the renewable energy source will help in meeting the requirements of limiting greenhouse-gas effects, and conserve the environment from pollution, global warming, ozone layer depletion, etc. There are various naturally available renewable energy sources. One of these sources is solar energy. Solar energy is available in abundance throughout the world and is the cleanest of all known energy sources. There are various devices that can be used to harness solar energy. One of such devices is a thermo-syphon. Thermo-syphon converts the solar energy obtained from the Sun into thermal energy of a working fluid. This thermal energy in the working fluid can be used for various industrial and household activities. In a closed loop thermo-syphon system, the working fluid circulates within the thermo-syphon loop via natural convection phenomenon and does not need any external devices, such as a pump. Therefore, it is considered to be one of the most efficient devices for the heat transfer. Moreover, the absence of a pumping device reduces the manufacturing and maintenance costs of a thermo-syphon system. The heat exchange process in the thermo-syphon is a complicated process, which considers the heat convection phenomenon. Therefore, to understand the natural convection process in the thermo-syphon and their effect on the thermal performance of the system a Computational Fluid Dynamics (CFD) based techniques have been used. Numerical results obtained have been verified against the experimental results, and they match closely with each other. The comparison between the CFD and experimental result, suggest that CFD can be used as an effective tool to analyse the performance of a thermo-syphon with reasonable accuracy. In order to investigate the flow structure within the thermo-syphon system, detailed qualitative and quantitative analyses have been carried out in the present study. The qualitative analysis of the flow field includes descriptions of the velocity magnitude and the static temperature distributions contours within the closed loop thermo-syphon system. Furthermore, the variation in the temperature of water within the storage tank, temperature of the working fluid, heat transfer coefficient, wall shear stress, and local velocity and temperature distribution of the working fluid within thermo-syphon loop have been quantified as a function of time. In addition, numerical studies have been conducted to identify the effects of various geometrical parameters, which include the number of the riser pipes, length-to-diameter ratio of the riser pipe on the thermal performance of a closed loop thermo-syphon system. Moreover, a further investigation has been carried out to analyse the effect of various heat flux conditions and different transient thermal loadings on the thermal performance of a closed loop thermo-syphon system. Based on these analyses some novel semi-empirical relations have been developed to predict the thermal performance of the thermo-syphon, which is one of the focal points of this research. Another goal of the current study is to improve the thermal performance characteristic of thermo-syphon solar water heating system using an enhancement device to improve the heat transfer. This aspect of the work focuses on the increasing energy conversion from the riser pipes to the working fluid within the thermo-syphon loop. This is accomplished by increasing the surface area of riser pipes by employing several design modifications, such as straight, wavy and helical pipes, within the riser pipes, while maintaining the amount of the working fluid constant within the closed loop thermo-syphon system. In this study, a comparative analysis has been carried out for these new design modifications to identify the best in terms of heat transfer coefficient, heat gain in collector etc., as an indication of thermal performance. According to the findings of this analysis, the model comprising of pipe inside the riser pipe depict better thermal performance as compared to other models. After defining the best design modification, a further detailed investigation has been carried out between the traditional and modified design (straight pipe inside the riser pipe) using experimental and numerical method. Established methods regarding the design process of thermo-syphons are very limited, and they are severely limited in estimating important design parameters, such as useful heat gain and heat transfer coefficient, which have a significant impact on the thermal performance of thermo-syphon system/loop. A design methodology has been developed to enrich the design process of a closed loop thermo-syphon solar water heating system. The developed methodology is more efficient and reliable since it is capable of estimating various geometrical and thermal parameters, such as collector area, diameter and length of the riser pipes, distance between the centers of the riser pipes, heat transfer coefficient, temperature of the working fluid and the mass flow rate. This design methodology is user friendly and robust.