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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.
561

Pellon alarajan muutos ja sen vaikutukset viljelyyn ja ympäristöön Keski-Pohjanmaalla ja Pohjois-Pohjanmaan eteläosassa

Typpö, A. (Asser) 07 June 2005 (has links)
Abstract This research examines the lower edge of arable land in cultivating littoral land and its effects on spring sowing Central Ostrobothnia and in the southern areas of Northern Ostrobothnia. This doctoral thesis develops methods to raise the lower edge of arable land in low littoral land. The methods are based on contribution margin, the gross profil of yield, the relocation of dry margin and the realigning of littoral land's area descriptor. In addition, outdated littoral land profil and loss evaluation criteria are renewed. The objective of the research is to decrease environmental damages and to improve cultivation. Another objective in raising the lower edge of arable land is to enhance the forming of protective noncultivated belts. Ten lakes from the hydrologic areas of the rivers Perhonjoki, Kalajoki and Pyhäjoki were chosen for the research, one half of them were in their natural state and the other half were regulated. The research consisted of comparing the sowing dates and patch yields (moisture content 14%) of the sample parcels (104 observations) chosen from littoral land around the lakes to the corresponding figures of sample parcels selected from outside the areas influenced by water level variation. The findings are from 1985–1991 and 1996–1998. The cultivated plants were barley, oats and hay. The sample area research was completed with interviews. Furthermore, the research examined the dependence of air pore space of the soil cultivation layer on the dry margin. The research result indicate that the lower edge of arable land has to be raised, for lakes in their natural state the rise would be on average 35 ± 4 cm (67 observations) and for regulated lakes on average 39 ± 4 cm (61 observations). The minimum dry margins required by soil cultivation and sowing will be 69 ± 5 cm (67 observations) and 78 ± 5 cm (61 observations). Thus, the lowest part of the waterfront will not be cultivated anymore. The contribution margin of the field is not changed. Sowing can be done earlier and air pore space and viability increase. The condensation detriment of the soil cultivation layer, the workload needed for cultivation and the nutrient load in hydrologic areas will be decreased. Measuring and locating protective non-cultivated belts becomes easier. The state of environment is improved. The evaluation of profit and loss is modernized. / Tiivistelmä Tutkimuksessa tarkastellaan rantamaiden viljelyksessä pellon alarajaa ja sen vaikutuksia kevätkylvöihin Keski-Pohjanmaalla ja Pohjois-Pohjanmaan eteläisellä osalla. Työssä kehitetään katetuottoon, sadon bruttotuottoon, kuivavaran siirtoon ja rantamaan pinta-alan kuvaajan oikaisuun perustuvat menetelmät pellon alarajan määrittämiseksi alavilla rantamailla. Samoin pyritään nykyaikaistamaan rantamaiden hyödyn- ja vahingonarviointia. Tutkimuksen tavoitteena on vähentää viljelyn aiheuttamia ympäristöhaittoja sekä parantaa samalla itse viljelyä. Pellon alarajan määrittämisen yhteydessä on tavoitteena edistää myös suojavyöhykkeiden perustamista. Kohdejärvinä oli Perhonjoen, Kalajoen ja Pyhäjoen vesistöjen kymmenen järveä, joista puolet oli luonnontilaisia ja puolet säännösteltyjä. Järvien rantatiloilta valittujen koelohkojen (104 kpl) kylvöaikoja ja ruutusatoja (kosteuspitoisuus 14 %) verrattiin vedenkorkeuksien vaihteluista riippumattomien vertailulohkojen vastaaviin arvoihin. Havaintovuodet olivat 1985–1991 sekä 1996–1998. Viljelykasveja olivat ohra ja kaura sekä heinä. Koealuetutkimuksia täydennettiin haastatteluina. Lisäksi tarkasteltiin muokkauskerroksen ilmahuokostilan riippuvuutta kuivavarasta määritettynä järven vedenkorkeudesta. Tutkimustulosten mukaan pellon alarajaa on korotettava nykyisestään luonnontilaisilla järvillä keskimäärin 35 ± 4 cm (n = 67) ja säännöstellyillä järvillä keskimäärin 39 ± 4 cm (n = 61). Kylvön vaatimat kuivavarat määritettyinä järvien vedenkorkeuksista tulevat olemaan vastaavasti 69 ± 5 cm (n = 67) ja 78 ± 5 cm (n = 61). Tällöin rantalohkon alavimmalta osalta viljely poistuu. Pellon katetuotto ei muutu. Kylvö aikaistuu, ilmahuokostila kasvaa ja kulkukelpoisuus paranee. Muokkauskerroksen tiivistymishaitta ja viljelyn työnmenekki sekä vesistöön kohdistuva ravinnekuormitus vähenevät. Suojavyöhykkeiden mitoitus ja sijoitus helpottuvat. Ympäristön tila paranee. Hyödyn ja vahingon arviointi nykyaikaistuu.
562

MEMS-enabled micro-electro-discharge machining (M³EDM)

Alla Chaitanya, Chakravarty Reddy 11 1900 (has links)
A MEMS-based micro-electro-discharge machining technique that is enabled by the actuation of micromachined planar electrodes defined on the surfaces of the workpiece is developed that eliminates the need of numerical control machines. First, the planar electrodes actuated by hydrodynamic force is developed. The electrode structures are defined by patterning l8-µm-thick copper foil laminated on the stainless steel workpiece through an intermediate photoresist layer and released by sacrificial etching of the resist layer. The planer electrodes are constructed to be single layer structures without particular features underneath. All the patterning and sacrificial etching steps are performed using dry-film photoresists towards achieving high scalability of the machining technique to large-area applications. A DC voltage of 80-140 V is applied between the electrode and the workpiece through a resistance-capacitance circuit that controls the pulse energy and timing of spark discharges. The parasitic capacitance of the electrode structure is used to form a resistance capacitance circuit for the generation of pulsed spark discharge between the electrode and the workpiece. The suspended electrodes are actuated towards the workpiece using the downflow of dielectric machining fluid, initiating and sustaining the machining process. Micromachining of stainless steel is experimentally demonstrated with the machining voltage of 90V and continuous flow of the fluid at the velocity of 3.4-3.9 m/s, providing removal depth of 20 µm. The experimental results of the electrode actuation match well with the theoretical estimations. Second, the planar electrodes are electrostatically actuated towards workpiece for machining. In addition to the single-layer, this effort uses double-layer structures defined on the bottom surface of the electrode to create custom designed patterns on the workpiece material. The suspended electrode is electrostatically actuated towards the wafer based on the pull-in, resulting in a breakdown, or spark discharge. This instantly lowers the gap voltage, releasing the electrode, and the gap value recovers as the capacitor is charged up through the resistor. Sequential pulses are produced through the self-regulated discharging-charging cycle. Micromachining of the stainless-steel wafer is demonstrated using the electrodes with single-layer and double-layer structures. The experimental results of the dynamic built-capacitance and mechanical behavior of the electrode devices are also analyzed. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate
563

Usinage à sec ou MQL : quantification et prise en compte des dilatations thermiques durant le process / Dry or MQL machining : quantification and consideration of thermal distortions along the process

Boyer, Henri-francois 12 June 2013 (has links)
L'industrie automobile cherche à réduire son utilisation des liquides de coupe en usinage pour des raisons économiques, environnementales et sanitaires. Les fabricants développent ainsi la démarche Minimum Quantity Lubrication qui vise à réduire au strict minimum l'utilisation des liquides de coupes en usinage. En l'absence de liquide de coupe, la stabilisation thermique de la pièce n'est plus assurée et des échauffements locaux apparaissent. Ces échauffements créent des déformations qui doivent être quantifiés et pris en compte afin d'assurer la conformité de la géométrie produite.Une démarche de modélisation de l'échauffement d'une pièce pendant l'usinage est présentée. Le modèle obtenu permet à la fois de quantifier la quantité de chaleur introduit dans la pièce pour des usinages simples et de simuler les déformations d'une pièce complexe lors de l'enchainement d'opération d'usinage. Cette quantification repose sur une méthode inverse. Elle est appliquée à des opérations de fraisage, perçage et taraudage d'un alliage d'aluminium AS9U3. Dans un second temps, une étude de l'influence de l'ordonnancement des opérations d'usinage d'un carter de boite de vitesses automobile sur la qualité de la géométrie produite est conduite. Cette étude illustre l'intérêt du modèle de simulation et des outils développés pendant la thèse. Enfin, les enjeux économiques et environnementaux de la technologie MQL seront abordés. / The application of MQL or dry machining in mass production becomes more and more accepted. Dry (MQL) machining is a very efficient solution to reduce the usage of cutting fluids and represents an effective measure for an environmental friendly production. However, these techniques do not benefit any more from the stabilization in temperature obtained with cutting fluids. More important and more heterogeneous increases of the temperature are observed. This leads to distortions of the work piece during machining which are necessary to be taken into account to maintain the geometrical quality of the manufactured surfaces.A model of the warm-up of a part during machining is presented. The obtained model allows to quantify heat introduced into the work piece for simple operations and to feign the distortions of a complex part when operations are enchained. This quantification is based on an inverse method. It is applied for reaming, drilling and tapping process for an aluminum alloy AS9U3. Secondly, a study about influence of operations organization is done. We use the model to quantify distortions an aluminum clutch case along machining. This study illustrates interest of the model and of tools developed during the PhD. In a last part, economic and environmental stakes of the MQL approach are discussed.
564

Advanced Design and Development of Novel Microparticulate/Nanoparticulate Dry Powder Inhalers Targeting Underlying Mechanisms in Respiratory Diseases

Muralidharan, Priyadarshini, Muralidharan, Priyadarshini January 2017 (has links)
Chronic respiratory diseases such as asthma, COPD, pulmonary fibrosis are more prevalent throughout the world. For some of these diseases there is no cure, the current treatment options manages the symptoms and acute exacerbation. The new approach to find a curative therapy for respiratory diseases is by targeting the cellular / molecular pathways that either cause the disease or has the potential cure the disease. It becomes important to target the respiratory system in treating these diseases to increase the delivered dose and reduce the unwarranted adverse effects. Dry powder inhaler (DPI) is a targeted drug delivery dosage form commonly used to target the airways to treat respiratory diseases. There are two components to dry powder inhaler product – powdered drug formulation and inhaler device; a unified performance of the two is essential for a successful product. In this study, dry powder aerosol of novel drug compounds that targets the underlying cellular and molecular mechanism are developed for the first time. Advanced organic closed mode spray drying technique was used to the produce microparticulate/ nanoparticulate formulations. The formulation of the novel compounds involved utilizing sugar based excipients. Each formulation that was produced was comprehensively characterized in the solid state. The safety of these formulations were tested in in vitro human pulmonary cell lines. The in vitro aerosol dispersion of the spray dried drugs were tested using three FDA approved human inhaler devices. The influence of the inhaler device resistance and spray drying process conditions on the aerosol dispersion was evaluated. Preliminary testing of the formulations in in vivo animal models shows promising results in treating chronic respiratory diseases with these superior aerosol formulations.
565

Skip-a-day feeding does not cause difference in liver lipid content in broiler breeders

Sander, Elin January 2017 (has links)
There has long been evidence for increased lipids in the liver of chickens exposed to feed restriction, commonly used for production hens. Lipogenesis is an important part of the metabolism and storing of glucose, a source of energy. Few studies compare the difference of lipids in the liver in chickens between regular feed restriction and skip-a-day diets, despite differences in lipid content found in other organs and in overall carcass. In this study I experimentally investigate if a difference in lipid content can be found in broiler breeders exposed to two different feeding regimes, 65 % feed restriction and 5:2 skip-a-day, along with the difference between days and time points (a.m. and p.m.). I also experimentally investigate the effect on dry weights of the liver. I expected to see a difference in lipids of the liver, with an increase found in skip-a-day birds. However, a difference could only be observed in the dry weights of the livers in birds exposed to skip-a-day feeding. Although there was no significant change in lipids, there is a pattern for increase in lipids in skip-a-day birds. Therefore, the conclusion can be drawn that an increase in lipogenesis caused by skip-a-day diet exists but it was not big enough to cause a significant difference in lipid content. For the dry weights of the livers, we can suspect lipids and glycogen as the reason for the increased weight but to determine exactly how these two components affect the skip-a-day birds’ further inquiry is needed.
566

An analysis of policy making for dry port location and capacity : a case study on Alexandria

ElGarhy, Aya Mostafa January 2016 (has links)
Container terminal capacity is a crucial issue for port and terminal operators nowadays as it is one of the key points for their success and increasing their competitive market position in the maritime industry. Therefore, researchers have tried to find solutions for the over capacity problem that faces many terminal operators. This research suggests dry ports as one of the most suitable solution for this problem through proposing a structured framework to adopt the right policy decisions for Dry Port location and capacity. To achieve the presented framework some areas were addressed in detail to have the full picture clear. The current status of the global container sector was assessed, also, the main capacity problems of container terminals with a view to reviewing the suggested solutions was investigated, hence the need for dry ports. In addition, policies for providing optimal location and capacity decisions for container terminals were identified. A technique that supports assessing container terminal location and capacity policy decisions with particular reference to dry ports were developed. Moreover, a case study on Alexandria International Container Terminal for validating the results was conducted. The current research was facilitated by experts from the maritime transport industry, through the application of the Delphi Technique. Applying such a technique enables collaborating experts to share experience modify statements and re-asking to reach a final exact answer that could be generalized. The consensus achieved will help build knowledge and understanding of potential Dry Ports’ policies of the maritime transport sector. This research seeks to make an original contribution to knowledge by developing a structured framework to identify policy decisions for location and capacity of Dry Ports using a Delphi technique as a support tool for terminal managers and operators, port planners, policy makers, and investors in deciding decisions relevant to Dry Port investment.
567

Qualidade de processamento e envelhecimento fisiológico de tubérculos de batata produzidos durante a primavera e o outono na região central do Rio Grande do Sul / Processing quality and physiological aging of potato tubers roduced during spring and autumn growing conditions in the central region of Rio Grande do Sul

Freitas, Sergio Tonetto de 20 January 2006 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Potato tubers can be used as food or seed. Potatoes are mostly sold for tablestock and processing consumptions. Each destination has its own requirements to attend consumers exigencies. The aim of this work was to evaluate the processing quality and physiological aging of potato tubers produced during spring and autumn growing conditions in Rio Grande do Sul (RS). Tubers of 15 potato clones were evaluated for processing quality during spring 2003 and autumn 2004. The best performance of chips color, dry matter, and reduced sugar was obtained with potatoes of the clones SMIJ461-1, SMIJ319-1, SMIJ456-4Y, SMIC148-A, SMIDO40-4RY and SMIH095-1. Among these clones, SMIDO40-4RY and SMIH095-1 were less affected by temperature and sunlight conditions of the RS growing seasons. The clones SMIJ461-1 and SMIJ456-4Y cultivated during spring showed the highest dry matter and the lightest chip color. The physiological aging was studied in potato tubers of the Asterix, SNINIA793101-3 and SMIJ461-1 clones produced during spring and autumn 2004 and stored at 4, 8, 12 and 25°C for 180 days. The physiological aging of the three evaluated clones was affected by the growing conditions. Potato tubers cultivated in autumn and stored at 4 and 8°C remained dormant for 180 days. When tubers were produced during spring, only the clones SMINI793101-3 and SMIJ461-1 stored at 4°C remained dormant for 180 days. The growing conditions and genetic differences influence both processing quality and physiological aging of potato tubers. The storage at low temperature is efficient to delay physiological aging only during the dormant period of the potato tubers. / Os tubérculos de batata podem ser destinados para o consumo ou semente. Para o consumo, estes podem ser utilizados para mesa ou para processamento. Ambas as finalidades exigem tubérculos com qualidades distintas, as quais são essenciais para atender as necessidades do consumidor. O objetivo deste trabalho foi avaliar a qualidade de processamento e o envelhecimento fisiológico de tubérculos produzidos durante a primavera e o outono na região central do Rio Grande do Sul. A qualidade de processamento foi avaliada em 15 clones produzidos durante a primavera de 2003 e o outono de 2004. O envelhecimento fisiológico foi estudado em tubérculos dos clones Asterix, SNINIA793101-3 e SMIJ461-1 produzidos durante o outono e primavera de 2004 e armazenados a 4, 8, 12 e 25°C por um período de 180 dias. Para qualidade de processamento, os clones SMIJ461-1, SMIJ319-1, SMIJ456-4Y, SMIC148-A, SMIDO40-4RY e SMIH095-1 foram os que apresentaram o melhor desempenho em coloração dos chips e teores de massa seca e açúcares redutores. Dentre esses clones, SMIDO40-4RY e SMIH095-1 foram os menos influenciados pelas épocas de cultivo de outono e primavera na região central do RS. Os clones SMIJ461-1 e SMIJ456-4Y apresentaram maior teor de massa seca e coloração mais clara dos chips no cultivo da primavera. De acordo com a avaliação do envelhecimento fisiológico, os três clones sofreram influência das condições de cultivo. O cultivo de outono combinado com o armazenamento a 4 e 8°C manteve os tubérculos dos diferentes clones em estádio de dormência por 180 dias. Quando os tubérculos foram produzidos na primavera, somente os clones SMINI793101-3 e SMIJ461-1 submetidos a temperatura de 4°C mantiveram a dormência durante os 180 dias de armazenamento. As condições de cultivo e as diferenças genéticas alteram tanto a qualidade de processamento quanto o envelhecimento fisiológico dos tubérculos. O armazenamento dos tubérculos a baixa temperatura é eficaz para retardar o envelhecimento fisiológico somente durante o período de dormência.
568

Development and Validation of a Remote Sensing Model to Identify Anthropogenic Boreholes that Provide Dry Season, Refuge Habitat for <i>Anopheles</i> Vector Mosquitoes in Sub-Saharan Africa

Kukat, James Pkemoi 16 June 2016 (has links)
A lack of surveillance systems is an impediment to public health intervention for perennial vector-borne disease transmission in northern tropical savanna region of Kenya. The population in this area are mostly poor nomadic pastoralists with little acquired functional immunity to Plasmodium falciparum, due to infrequent challenges with the parasite. A common characteristic in tropical savanna climatic zone is the availability of riverbeds that have anthropogenic boreholes that provide malaria vector mosquitoes, such as Anopheles gambiae s.l and Anopheles funestus, with aquatic refuge habitats for proliferation and endemic transmission to proximity human households during the dry-season. Unfortunately, currently there have been no entomological investigations employing field or remotely sensed data that can characterize and model anthropogenic borehole habitats focusing on the dry-land ecology of immature Anopheles mosquitoes in sub-Sahara Africa. The goal of this investigation was three-fold: (I) to employ WorldView-3 (0.31 meter spatial resolution) visible and near infra-red waveband sensor data to image sub-Saharan land cover associated with vector-borne disease transmission; (II) to remotely identify anthropogenic boreholes in three riverbeds that were surveyed to determine whether they provide malaria vectors with refuge habitat and maintain their population during the dry season in Chemolingot, Kenya, and (III) to obtain a radiometric/spectral signature model representing boreholes from the remotely-sensed data. The signature model was then interpolated to predict unknown locations of boreholes with the same spectral signature in Nginyang Riverbed, Kenya. Ground validation studies were subsequently conducted to assess model’s precision based on sensitivity and specificity tests.
569

Analysis of Production Process of Fine Dry Ice Particles and Application for Surface Cleaning / ドライアイス微粒子の形成プロセスの解析と表面洗浄への応用

Liu, Yi-Hung 26 March 2012 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16887号 / 工博第3608号 / 新制||工||1545(附属図書館) / 29562 / 京都大学大学院工学研究科化学工学専攻 / (主査)教授 松坂 修二, 教授 宮原 稔, 教授 大嶋 正裕 / 学位規則第4条第1項該当
570

Investigation of pristine and oxidized porous silicon

Pap, A. E. (Andrea Edit) 21 June 2005 (has links)
Abstract While numerous publications deal with the properties and applications of porous silicon (PS), some of the related topics are not complete or could be investigated from different aspects. Therefore, the main objective of this thesis is to provide novel information associated with the optical and chemical properties of PS. For the investigations, various PS samples are manufactured by electrochemical dark etching of boron-doped p+-type Si wafers. Amongst others, (i) the wavelength-dependent refractive indices of freestanding PS monolayers having different porosities were obtained from optical transmission and reflection spectra in the 700–1700 nm wavelength range, and compared to those calculated from Bruggeman's effective medium approximation (EMA). The refractive indices of the PS samples are shown to be described well with the EMA. In addition, optical scattering at the air-PS interface was demonstrated. (ii) Multilayer stacks are created by alternating the porosities of PS layers within the same sample to form Bragg filters. The Bragg conditions of the filters are calculated and compared to optical transmission measurements. (iii) The oxidation of PS membranes in dry air is investigated with emphases on the reaction kinetics and on the structural changes of the porous matter. As revealed, oxidation proceeds faster in PS than in Si bulk. The formed SiO2 is amorphous and causes stress in the lattice of the residual Si skeleton. (iv) The effect of oxidation extent of PS layers on the growth mechanism of multi-walled carbon nanotubes (CNTs) is investigated. The density of the CNT network is found proportional to the oxidation extent of the substrates. (v) Finally, the chemically-reductive nature of PS is studied and exploited via the immersion plating method to deposit palladium and silver nanoparticles in the nanopores and on the surface of PS samples. The presented novel results have potential in silicon-based technologies, including integrated active and passive optical components (waveguides, filters, antireflection coatings, optical gas/liquid sensors), electronic devices (electrochemical gas/liquid sensors, diodes, field effect devices) and selective chemical catalysis (substrates, growth templates).

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