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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Photonic Crystal Nanobeam Cavities for Biomedical Sensing

Quan, Qimin 21 June 2013 (has links)
Manipulation of light at the nanoscale has the promise to enable numerous technological advances in biomedical sensing, optical communications, nano-mechanics and quantum optics. As photons have vanishingly small interaction cross sections, their interactions have to be mitigated by matters (i.e. quantum emitters, molecules, electrons etc.). Waveguides and cavities are the fundamental building blocks of the optical circuits, which control or confine light to specific matters of interest. The first half of the thesis (Chapters 2 & 3) focuses on how to design various photonic nanostructures to manipulate light on nano- to micro- scale, especially to modify the light-matter interaction properties. Chapter 2 discusses how nano-slot waveguides and photonic crystal nanobeam waveguides are able to modify the emission of quantum emitters, in a different way that normal ridge waveguides are not able to. Chapter 3 focuses on a more complicated and powerful structure: the photonic crystal nanobeam cavity. The design, fabrication and characterization of the photonic crystal nanobeam cavities are described and demonstrated in detail, which lays out the foundation of the biomedical sensing applications in the second half of the thesis. The second half of the thesis (Chapters 4 & 5) focuses on the application of photonic crystal nanobeam cavities in the label-free sensing of biomedical substances. Chapter 4 demonstrates detection of solutions with different refractive index (aceton, methanol, IPA etc.), glucose concentration, single polystyrene nanoparticles and single streptavidin bio-molecules. Chapter 4 proposes a novel nonlinear optical method to further enhance the sensitivity. Chapter 4 also demonstrates high quality nanobeam cavities fabricated in polymers, that open up a new route to decrease the cost, as well as to achieve novel applications with functional polymers. The broader impact of this technology lies in its potential of commercialization of a new generation of biosensors with high sensitivity and high integration. Chapter 5 discusses progresses towards instrumentation of the nanobeam cavity sensing technology for research & development apparatus, as well as point-of-care diagnostic tools. / Engineering and Applied Sciences
142

Analysis of high performance interconnect in SoC with distributed switches and multiple issue bus protocols

Narayanasetty, Bhargavi 26 July 2011 (has links)
In a System on a Chip (SoC), interconnect is the factor limiting Performance, Power, Area and Schedule (PPAS). Distributed crossbar switches also called as Switching Central Resources (SCR) are often used to implement high performance interconnect in a SoC – Network on a Chip (NoC). Multiple issue bus protocols like AXI (from ARM), VBUSM (from TI) are used in paths critical to the performance of the whole chip. Experimental analysis of effects on PPAS by architectural modifications to the SCRs is carried out, using synthesis tools and Texas Instruments (TI) in house power estimation tools. The effects of scaling of SCR sizes are discussed in this report. These results provide a quick means of estimation for architectural changes in the early design phase. Apart from SCR design, the other major domain, which is a concern, is deadlocks. Deadlocks are situations where the network resources are suspended waiting for each other. In this report various kinds of deadlocks are classified and their respective mitigations in such networks are provided. These analyses are necessary to qualify distributed SCR interconnect, which uses multiple issue protocols, across all scenarios of transactions. The entire analysis in this report is carried out using a flagship product of Texas Instruments. This ASIC SoC is a complex wireless base station developed in 2010- 2011, having 20 major cores. Since the parameters of crossbar switches with multiple issue bus protocols are commonly used in SoCs across the semiconductor industry, this reports provides us a strong basis for architectural/design selection and validation of all such high performance device interconnects. This report can be used as a seed for the development of an interface tool for architects. For a given architecture, the tool suggests architectural modifications, and reports deadlock situations. This new tool will aid architects to close design problems and bring provide a competitive specification very early in the design cycle. A working algorithm for the tool development is included in this report. / text
143

EFFECTS OF TEMPERATURE ON THE SERVICE-LIFE OF LANDFILL LINERS AND POTENTIAL TEMPERATURE CONTROL STRATEGIES

HOOR, AZADEH 10 August 2011 (has links)
Landfill facilities are required to have a barrier system that will limit escape of contaminants to groundwater and surface water for the contaminating lifespan of landfill. Heat generated by the biodegradation of waste and chemical reactions in landfills reduces the service-life of geomembranes by accelerating the ageing process of high-density polyethylene. It may also lead to the desiccation of clay components of the liners. Four considerations with respect to the evaluation of the potential effects of liner temperature on the service-life of liners and the potential control of liner temperature are examined. For the first time, the likely temperature and service-life of a secondary geomembrane in a double composite lining system is predicted. It is shown that, in some cases, the temperature is likely to be high enough to substantially reduce the service-life of the secondary geomembrane. The possible effectiveness of using tire chips as passive thermal insulation between the primary and secondary liners, as well as traditional soil materials, is then explored. For the barrier system and contaminant examined, the results show that tire chips could potentially lower the temperature of the secondary geomembrane sufficiently to significantly extend its service-life. However, the use of tire chips brings about other practical issues, which are also discussed in this study. An active alternative method of controlling the increase in the landfill liner temperature is then examined. This approach, which is inspired by geothermal heat pumps, involves an array of cooling pipes beneath the waste. Numerical modelling showed that the hypotetical introduction of the cooling pipes resulted in a reasonable decrease in liner temperature. It is suggested that the proposed technique warrants further consideration. Finally the conditions that may lead to the desiccation of geosynthetic clay liners used in composite liners due to waste generated heat are examined and recommendations regarding possible means of mitigating the effects of heat on the performance of GCLs are presented. For example, numerical modelling shows that the hydration of GCL prior to waste placement, liner temperature, overburden stress, depth to aquifer and moisture content and grain size of subsoil affect desiccation. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2011-07-31 07:34:33.165
144

Bose-Einstein condensates in magnetic double well potentials

Schumm, Thorsten 20 February 2006 (has links) (PDF)
Ce manuscrit présente deux réalisations d'un double puit magnétique pour des condensats de Bose-Einstein (CBE) sure une puce atomique. Une approche utilise des pièges statiques, crées par des micro fils (en amènent ?) manipulant les atomes proche a la surface de la puce. Comme dans toute manipes, on observe une fragmentation du nuage atomique, quand on approche les atomes vers la structure piégeant. Cet effet était expliqué par une déviation du courant dans le fil à cause d'une rugosité des bords. Pour éviter la fragmentation, une nouvelle technique de fabrication (lithographie a faisceaux a électrons, évaporation d'or) a été utilisé pour créer des fils d'un section de 700nm et une qualité amélioré. Un CBE a été crée et chargé dans le double puit généré par la nano structure. On a testé le double puit comme séparatrice avec des atomes thermiques. Des nombreuses problèmes techniques nous empêchent pour le moment d'effectuer la manip avec un CBE.<br />La deuxième approche poursuit dans cette thèse combine des pièges magnétique statique avec un champ (RF) magnétique alternant et génère un double puit dans le potentiel habillé. Car ce schéma peut être réalisé loin de la surface de la puce, la fragmentation n'apparaisse pas et on a pu séparer un CBE en deux. Une interféromètre d'ondes a matière est réalisé en recombinant les deux nuages en expansion libre. La figure d'interférence permet de mesurer la phase relative, on trouve une distribution étroite de cette phase et donc la séparation est cohérente. L'évolution de la phase relative est mesurée pendant et après la séparation et contrôlé par déséquilibrant le double puit.
145

Comparison of fat free and regular potato chips : taste acceptability and gastrointestinal symptoms in 18-21 year-old female college students

Wendt, Ellen B. January 2000 (has links)
There is no abstract available for this thesis. / Department of Family and Consumer Sciences
146

Obtenção de chips de berinjela (Solanun melongena L.) mediante processo combinado de desidratação osmótica em solução ternária e secagem convectiva

Fernandes, Maristela Alves 15 June 2012 (has links)
Made available in DSpace on 2015-04-17T14:49:22Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1134733 bytes, checksum: 28cffd4f9ffcc33dac5566773d86f7c7 (MD5) Previous issue date: 2012-06-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work aimed to utilize the combined osmotic dehydration and convective drying process to obtain eggplant chips by a non-conventional healthier and more low cost way. The combined process was studied through a factorial experimental design having as independent variables the temperature (30-50°C), sucrose (27,5 to 42,5% w/w) and sodium chloride (3,75 to 6,25% w/w) solution concentrations and immersion time (142,5 to 247,5 min.). The dependent ones were the water loss (PA), sucrose gain (GSac), sodium gain (GSódio), and the GSac/GSódio ratio. Samples from each osmotic condition were dried at 60°C for 4 hours in a convective dryer with a 1m/s air velocity. The objective was to obtain a maximum water loss with a minimum sucrose and sodium impregnation. Statistic models were well fitted according to the Response Surface Methodology. Once PA was above 90% and water activity was less than 0,4 for all samples, it was used the GSac/GSódio ratio as a parameter for choosing the best process condition which should be maximum. Thus, from this analysis, the best way to obtain eggplant chips was at 50°C, with a sucrose and sodium chloride concentrations of 45% and 7,5%, respectively, for 127,5 minutes. This independent variables combination led to a final product with its sodium content sensory attenuated due the sucrose presence and based on this point of view, it could be considered a healthier product compared with similar commercial, as well as by non-use of conventional frying process. / O presente trabalho teve como objetivo a utilização da tecnologia combinada de desidratação osmótica e secagem para obtenção de berinjela seca em forma de chips , de modo a aproveitar esta matéria-prima e obter um produto final, por vias não convencionais, mais saudável e de baixo custo. O processo de desidratação osmótica seguida de secagem convectiva foi realizado através de um delineamento experimental, tendo como variáveis independentes a temperatura (30 50°C), concentração de sacarose (27,5 42,5% p/p) e concentração de cloreto de sódio (3,75 6,25% p/p) da solução osmótica e o tempo de imersão (142,5 247,5 min.), e como variáveis dependentes PA, GSac, GSódio, GSac/GSódio e aw, secas numa temperatura e tempo de 60°C e 4 horas, respectivamente, a uma velocidade de 1m/s, onde o objetivo foi obter uma máxima perda de água com uma mínima incorporação de sacarose e sódio. Foram ajustados modelos de primeira ordem segundo a metodologia de superfície de resposta. Uma vez que PA foi acima de 90% e a aw foi menor que 0,4 para todos os ensaios, utilizou-se como parâmetro de escolha da melhor condição do processo, a análise do agente osmótico, mediante a razão GSac/GSódio, a qual deveria ser máxima, segundo a composição de amostras de batata chips comerciais. A condição ideal para obtenção de berinjela seca em forma de chips foi T=50ºC, CSac=45%, CSal=7,5%, t=127,5 minutos, onde tal fato implica em um produto final com um teor de sódio sensorialmente atenuado devido à presença da sacarose e sendo considerado, portanto, mais saudável em função dos menores teores de sódio e sacarose, quando comparado com os similares comerciais, assim como também, pela não utilização do processo de fritura convencional.
147

Energi- och miljöeffekter av mekanisk avvattning som försteg till torkning av träflis vid pelletsproduktion / Energy and environmental effects of mechanical dewatering as a pre-stage to thermal drying of wood chips in a pellets production

Lingman, Oskar January 2018 (has links)
Med rådande klimathot i form av ökande koldioxidhalter i vår jords atmosfär krävs stora gemensamma insatser för att minska utsläppen. Genom att välja bort fossila bränslen och istället använda miljövänliga energikällor skapar vi tillsammans en hållbar framtid. Träpellets är ett biobränsle tillverkat på biomassa i form av träflis och dess förbränning kan i princip ses som koldioxidneutral. Tillverkningen av bränslepellets är emellertid en energikrävande process där termisk torkning av råvaran står för en majoritet av energianvändningen under pelletstillverkningen, där träflisen torkas från 55–10% fukthalt genom kondensering. I och med den ökande efterfrågan av pellets kommer även större möjligheter till effektivisering, där torksteget i produktionen har stort fokus. Syftet med denna studie har varit att undersöka energi- och miljöeffekter av en ny tvåstegsteknik bestående av mekanisk avvattning som försteg till termisk torkning av träflis i en pelletsproduktion. Den mekanisk avvattningsteknik som undersökts är Drinor CDP - Continuous Dewatering Press. Det primära målet med arbetet har varit att undersöka Drinors CDP som försteg till en bandtork och pneumatisk tork för att slutligen svara på vilken av kombinationerna som ger lägst energianvändning och miljöpåverkan i form av utsläpp. Som referens kommer torkprocessen hos Stora Enso Timber Gruvön användas, där en bandtork i dag används som torksteg. Som delmål kommer två olika partikelstorlekar undersökas vid pneumatisk torkning bestående av spån och flis, detta för att utreda partikelstorlekars påverkan på pneumatisk torkning och om det ens är möjligt att pneumatiskt transportera större flis. Resultaten visar att mekanisk avvattning är en bra lösning för pelletsindustrin. Fallet med CDP i kombination med bandtork ledde till en energireducering med ca 50% och 35% minskade utsläpp som en följd, jämfört med referensfallet bestående av endast bandtork. Resultaten visade även att stora träflispartiklar kunde transporteras pneumatiskt vid en lufthastighet på drygt 23 m/s. Pneumatisk torkning bidrog till en hög användning av el på grund av höga temperaturer, vilket i sin tur leder till stora mängder koldioxidutsläpp. / With the occurring climate threats in the form of increasing levels of carbon dioxide in our Earth's atmosphere, major joint efforts are needed to reduce our emissions. By opting out of fossil fuels and instead using environmentally friendly energy sources, we help create a sustainable future. Wood pellets are a biofuel made from biomass in the form of woodchips and its combustion can in principle be seen as neutral. However, the production of wood pellets is an energy-consuming process where thermal drying of the wet wood chips accounts for a majority of the total energy use during pellet production, where wood chips are typically dried from 55 – 10% moisture by condensation. With an increasing demand for pellets, there will also be more opportunities for efficiency, where the drying stage in production has a large focus. The purpose of this study has been to investigate the energy and environmental effects of a new two-stage technique consisting of mechanical dewatering as a prestage to thermal drying of woodchips in a pellet production. The mechanical dewatering technology studied is the Drinor CDP - Continuous Dewatering Press. The primary goal of the work has been to investigate the Drinors CDP as a pre-stage to a packed moving bed and a pneumatic dryer to finally answer to which of the combinations provides the lowest energy use and environmental impact in terms of emissions. As a reference, the drying process of Stora Enso Timber Gruvön is used, where a packed moving bed is used as a single-stage dryer. As a secondary goal, two different particle sizes will be examined for pneumatic drying consisting of saw dust and wood chips, to investigate the impact of particle sizes on pneumatic drying, and whether it is even possible to pneumatically transport larger wood chips. The results show that mechanical dewatering is a good solution for the pellet industry. The case with a CDP in combination with a packed moving bed led to an energy reduction of about 50% and 35% reduced emissions as a result, compared to the reference case consisting only of a packed moving bed. The results also showed that large wood chip particles could be transported pneumatically at an air velocity of just over 23 m/s. Pneumatic drying contributed to a high use of electricity due to high temperatures, which in turn leads to large quantities of emissions.
148

Analýza pracovních technologií při zpracování dřevní suroviny rychle rostoucích topolů a obdobných dřevin pro jejich další využití. / Analysis of technologies for processing wood raw material fast-growing poplar trees and similar trees for further use.

PLEVKA, Vojtěch January 2010 (has links)
The dissertation analyzes the work technology in the processing of fast growing poplar trees and similar trees. In the experimental section were described two different methods of processing the lines of fast-growing poplar trees. It was further verified by the performance and suitability of use Doppstadt AK 450 shredder processing fast-growing poplars and similar trees.
149

Effekter av förpressad granflis för pelleteringsbarheten i en single pellet press / The effects of pre-pressing spruce wood chips for the pelletability in a single pellet press

Malm, Simon January 2018 (has links)
I en värld med ökande koldioxidhalter i atmosfären och höjd medeltemperatur, råder det inga tvivel om att vi står inför en rad utmaningar för att minska användandet av bland annat fossila bränslen som generar skadliga utsläpp. Det finns många alternativ till oljebaserade bränslen, och ett som har ökat markant de senaste åren är bränslepellets. Bränslepellets är ett träbaserat biobränsle som i sitt kompakta tillstånd erbjuder ett bra värmevärde och är klimatneutralt. För att tillverka pellets måste råmaterialet först termiskt torkas, från en fukthalt på ca 55 % till ca 10 %, vilket i dagsläget kan motsvara upp till en fjärdedel av hela energiåtgången i pelleteringsprocessen. Med den ökade efterfrågan av bränslepellets finns också ökade förutsättningar för energieffektiviseringar i pelletsproduceringen, speciellt i torkningssteget.   Drinor AB har tagit fram en avvattningsmaskin av biomaterial som heter CDP, och med den är det möjligt att avvattna biomaterial till ca 30 %, vilket skulle reducera både tiden och energin det tar att termiskt torka materialet. Avvattningen sker under tryck på minst 40 ton, där vattnet mekaniskt pressas ut ur råmaterialet. Hur avvattningen påverkar råmaterialet, speciellt i en pelletframställning, är oklart och syftet med detta arbete var att ta reda på hur pelleteringsegenskaperna påverkas efter pressning med CDP, och om det finns möjligheter att spara energi i malningsdelen i pelleteringsprocessen.   Målet med arbetet var att ta reda på hur CDP påverkar pelletskvaliteter i form av hårdhet och densitet, samt om friktionsutvecklingen i pelleteringsmatrisen förändras, genom att framställa pellets ur 3 scenarion. I ett scenario ska en traditionell pelletsframställning liknas, med endast termisk torkning och i de resterande två scenarion implementeras CDP som försteg till den termiska torkningen. I ett av dessa två scenarion mals inte träflisen innan pelletering, för att se om energi kan sparas utan att offra pelletskvalitet. Ett annat mål var att, per scenario, ta reda på vid vilken fukthalts- och temperaturkombination de bästa pelletsen tillverkades med avseende på hög densitet och hårdhet samt låg friktionsutveckling.   Resultaten visade att scenariot med CDP som komplement till termisk torkning och utan malningprocess, producerade pellets med högst hårdhet, högst densitet och lägst friktionsutveckling under båda fukthalterna på pelleteringsmaterialet och nästintill samtliga matristemperaturer. Det scenario som hade endast termisk torkning producerade pellets med lägst densitet och hårdhet samt högst friktion under nästan alla temperaturer och fukthalter.   När den bästa fukthalts- och temperaturkombinationen togs fram per scenario, så var scenariot med CDP och utan malning bäst. Pellets producerade där hade ökad densitet, nästan tredubblad hårdhet samt mer än halverad friktionsutveckling i pelleteringsmatrisen, jämfört med scenariot som imiterade traditionell pelletsframställning med endast termisk torkning.   Skulle det scenariot med CDP och utan malningsprocess implementeras i en verklig industriell skala skulle det innebära stora förutsättningar för ökad produktion av pellets med bättre kvalitet, samt ett minskat energianvändande i form av reducerad termisk torkning och minskat användande av malningsprocessen. / In a world with growing carbon dioxide contents in the atmosphere and elevated average temperature, there is no doubt that we are faced with a number of challenges to reduce the use of, among other things, fossil fuels that generate harmful emissions. There are many alternatives to oil-based fuels, and one that has increased markedly in recent years is fuel pellets. Fuel pellets are a wood-based biofuel that, in its compact state, offers a good thermal value and is climate neutral. In order to produce pellets, the raw material must first be thermally dried, from a moisture content of about 55 % to about 10 %, which can currently account for up to at least a quarter of the total energy consumption in the pelleting process. With the increased demand for fuel pellets, there are also increased possibilities for energy efficiency in the pellet production, especially in the drying stage.   Drinor AB has developed a biomaterial dewatering machine called CDP, with which it is possible to drain the biomaterial to a moisture content of about 30%, which would reduce both the time and the energy it takes to thermally dry the material. The dewatering pressure is at least 40 tonnes, where the water is mechanically squeezed out of the raw material. How the dewatering affects the raw material, especially in a pellet production, is unclear and the purpose of this work was to find out how the pelleting properties are affected after pressing with CDP and if there is potential for saving energy in the grinding process in the pelleting process.   The aim of the work was to find out how CDP affects pellet qualities in terms of hardness and density, and if the friction development in the pelleting dye changes, by making pellets out of 3 scenarios. In one scenario, traditional pellets production should be resembled, with only thermal drying, and in the remaining two scenarios, CDP is implemented as a complement to thermal drying. In one of these two scenarios, the wood chips were not milled before pelleting, to see if energy can be saved without sacrificing pellet quality. Another goal was to determine, by each scenario, what moisture and temperature combination the best pellets were produced with respect to high density and hardness and low friction development.   The results showed that the CDP scenario, as a complement to thermal drying and without grinding process, produced the hardest pellets, highest density and lowest friction development during both moisture levels of the pelleting material and almost all die temperatures. The scenario that only had thermal drying produced pellets with the lowest density and hardness, as well as maximum friction under almost all temperatures and moisture levels.   When the best moisture and temperature combination was achieved by each scenario, the scenario with CDP and without grinding was the best. Pellets produced there had increased density, almost triple the hardness, and more than half the friction development in the pelleting die, compared to the scenario that imitated traditional pellets production with only thermal drying.   Should the scenario with CDP and without grinding process be implemented on a real industrial scale, it would provide great conditions for increased production of better quality pellets, as well as reduced energy use in the form of reduced thermal drying and reduced use of the grinding process.
150

Estudio de prefactibilidad para la implementación de una planta procesadora de hojuela de papa deshidratada y papas fritas precocidas "ch'uñu foods"

Arribas-López, Diego-José, Franco-López, Arturo January 2016 (has links)
El proyecto consiste en identificar y demostrar la factible implementación y la exitosa operación financiera de una planta proveedora de hojuela de papa deshidratada (HPD) y papas fritas precocidas (PFC). Para satisfacer la escasez de HPD, debido a la alta demanda mundial y la creciente demanda en los restaurantes de PFC. Que se instalará en el distrito de Ate en la ciudad de Lima. Todo esto utilizando materias primas 100% peruanas y mano de obra local. / The proyect consist in identify and demonstrate the feasibility implementation and financial operation success of an dehydrated potato flake (DPF) and precooked fries (PF) provider plant. Due to shortage of DPF, because of the high global demand and growing demand on restaurants for PF. Which will be installed on the district of Ate in the city of Lima. All this using 100% Peruvian raw materials and local labor. / Trabajo de investigación

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