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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.
61

Analýza rychlostních a tlakových polí kapaliny, využitím křivočarých souřadnic / Analysis of the Velocity and Pressure Fields of the Liquid Using Curvilinear Coordinates

Stejskal, Jiří January 2017 (has links)
This work introduces a new method of hydraulic design of a centrifugal pump impeller. This method is based on a geometrical approach employing curvilinear coordinates that are used to formulate both the axisymmetrical flow model in a meridional shape and the final model of flow in a blade cascade taking into account the full 3D shape of the impeller blade. The solution to this model then directly provides the guidelines for shaping the impeller blade in order to suppress the secondary flows, thus increasing the impeller efficiency, which is demonstrated on a real impeller design case. The partial differential equations describing the flow in the blade cascade are numerically solved piecewise on each particular stream surface, which leads to a significant reduction of computational time.
62

Nova konfiguracija širokopojasnog nisko-šumnog pojačavača u CMOS tehnologiji / А new design of ultra-wideband low noise amplifier in CMOS technology

Đugova Alena 27 June 2016 (has links)
<p>Nisko-šumni pojačavač (NŠP) nalazi se u prijemnom delu bežičnog<br />primopredajnika neposredno nakon antene. NJegova uloga je da ulazni<br />signal određene frekvencije i male snage izdvoji i pojača iznad nivoa<br />šuma prijemnika. U okviru doktorske disertacije prikazane su i<br />opisane metode za projektovanje širokopojasnih (UWB) NŠP u CMOS<br />tehnologiji. Ukupno je predloženo devet novih konfiguracija NŠP. Na<br />osnovu dobijenih rezultata, u 0,18 &mu;m UMC CMOS tehnologiji<br />realizovan je i fabrikovan NŠP jednostavne topologije, koja<br />predstavlja zbir dva pristupa, pojačavačkog stepena kaskodne<br />strukture sa povratnom spregom i stepena sa višestrukim<br />iskorišćenjem struje. NŠP je projektovan za frekvencijski opseg od<br />3,1 do 5 GHz. Takođe, opisana je metoda za merenje parametara NŠP, a<br />zatim je i izvršena njegova karakterizacija.</p> / <p>In the transceiver chain the low noise amplifier (LNA) is placed in the frontend<br />of the receiver after the antenna. The LNA needs to isolate and amplify<br />received weak signal at a specific frequency above the noise level of the<br />receiver. In the scope of this doctoral dissertation methods for designing<br />ultra-wideband (UWB) LNA in CMOS technology are presented and<br />described. Nine new LNA configurations were proposed. Based on the<br />obtained results, simple LNA configuration, obtained by merging casode<br />feedback topology and current-reuse technique, was realized and fabricated<br />in 0.18 &mu;m UMC CMOS technology. The LNA is designed for the frequency<br />band from 3.1 to 5 GHz. In addition, the method for measurement LNA<br />parameters is described and the proposed LNA was characterized.</p>
63

Perú: Animación publicitaria de Inca-Kola 2019-2020 / Peru: Inca-Kola animated advertisement 2019-2020

López Kawanishi, Sofía del Pilar 07 October 2021 (has links)
El uso de la animación dentro de la publicidad ha pasado por diversas variaciones a lo largo de los años, se ha encontrado en anuncios publicitarios en forma de dibujos, caricaturas y ha pasado a personajes con movimiento para comerciales y personajes de marcas comestibles y de servicios. Se pretende demostrar que existen elementos de la animación utilizados en la publicidad que son fundamentales para transmitir mensajes, desarrollar personajes y establecer vínculos con los usuarios para motivar el consumo de bebidas gaseosas, como lo fue en el caso de Inca-Kola. El objetivo de esta investigación es analizar la narrativa de una lovemark desde el uso de la animación publicitaria en el Perú a través de un enfoque cualitativo haciendo uso del paradigma interpretativo, analizando la información con un diseño de estudio de caso, como técnica de recolección de datos el análisis de contenido haciendo uso de la técnica de recolección de datos y desarrollando un instrumento de estudio a la guía de análisis de contenido. Ello se aplicará a seis comerciales, los cuales son parte de la miniserie de comerciales de Inca-Kola “Habla Retornable”, a través de ellos se dará a conocer la construcción de los personajes animados y el contexto de la historia en comerciales animados. / The use of animation within advertising has undergone various variations over the years, it has been found in advertisements in the form of drawings, cartoons and has moved to moving characters for commercials and characters for food and service brands. It is intended to demonstrate that there are elements of animation used in advertising that are essential to transmit messages, develop characters and establish links with users to motivate the consumption of soft drinks, as was the case with Inca-Kola. The objective of this research is to analyze the narrative of a lovemark from the use of advertising animation in Peru through a qualitative approach using the interpretive paradigm, analyzing the information with a case study design, as a technique for collecting data. data content analysis making use of the data collection technique and developing a study instrument to the content analysis guide. This will be applied to six commercials, which are part of the Inca-Kola commercial miniseries “Habla Retornable”, through which the construction of the animated characters and the context of the story in animated commercials will be revealed. / Trabajo de investigación
64

Těhlice vozu kategorie Formule SAE / Wheel Hub Carrier for car of Formule SAE

Vymazal, Roman January 2008 (has links)
This thesis deals with a mechanical design of a front wheel hub carrier and a rear wheel hub carrier for Formula SAE. It contains the main design as well as the control of a screw and computer loading solve process. The essential objectives of this thesis are the optimization of the mechanical design and following manufacturing of desired parts and their practical usage in a Formula SAE race car.
65

Návrh zavěšení kol Formule Student / Design of Formula Student Wheel Suspensions

Urban, Marek January 2020 (has links)
Tato práce se se zabývá návrhem kinematiky zavěšení kol obou náprav. Na základě analýz jízdních dat, multi-body simulací v softwaru Adams Car, simulací v Matlabu a analytických kalkulací v Mathcadu, je navržena řada změn s cílem zlepšit jízdní vlastnosti vozu Formule student, tyto změny jsou následně implementovány do CAD modelu vozu. Jednotlivé změny kinematiky náprav jsou provedeny na základě analýzy konkrétního problému, který se snaží řešit. Jednou z problematik je zástavbová náročnost systému odpružení a zavěšení zadních kol, zde je cílem snížit hmotnost, výšku těžiště a moment setrvačnosti. Další problematikou je geometrie předního kola, kde je cílem zlepšit využití pneumatik a snížit síly v řízení. Dále se práce zabývá simulacemi elastokinematiky zadní nápravy, součástí je také návrh měřícího zařízení. V poslední části je zkoumán vliv provedených změn i elastokinematiky na jízdní dynamiku vozu v ustálených stavech za pomocí MM metody simulované s modelem celého vozu v Adams Car a zpracované v Matlabu.
66

Фракционо и тополошко уопштење једначине телеграфичара као модел електричног вода / Frakciono i topološko uopštenje jednačine telegrafičara kao model električnog voda / Fractional and topological generalization of telegraphers’s equation intansmission line modeling

Cvetićanin Stevan 27 October 2017 (has links)
<p>Предмет истраживања су фракциона и тополошка уопштења једначине<br />телеграфичара као модела електричног вода. Фракционо уопштење се<br />огледа у томе што су класичне конститутивне релације електричних<br />елемената замењене фракционим. Модификација конститутивних<br />релација омогућује да се узму у обзир коначно време релаксације и<br />поларизације диелектрика, као и формирања магнетског поља, односно<br />историја процеса поларизације и магнетизације. Тополошко уопштење<br />огледа се у томе што елементарно коло вода, поред стандардних<br />елемената, има кондензатор и у редној грани којим се моделира ефекат<br />нагомилавања наелектрисања дуж елекричног вода, односно коначно<br />време релаксације.</p> / <p>Predmet istraživanja su frakciona i topološka uopštenja jednačine<br />telegrafičara kao modela električnog voda. Frakciono uopštenje se<br />ogleda u tome što su klasične konstitutivne relacije električnih<br />elemenata zamenjene frakcionim. Modifikacija konstitutivnih<br />relacija omogućuje da se uzmu u obzir konačno vreme relaksacije i<br />polarizacije dielektrika, kao i formiranja magnetskog polja, odnosno<br />istorija procesa polarizacije i magnetizacije. Topološko uopštenje<br />ogleda se u tome što elementarno kolo voda, pored standardnih<br />elemenata, ima kondenzator i u rednoj grani kojim se modelira efekat<br />nagomilavanja naelektrisanja duž elekričnog voda, odnosno konačno<br />vreme relaksacije.</p> / <p>The subject of research is the fractional and topological generalization of the<br />telegraphers&rsquo;s equation in transmission line modeling. The fractional<br />generalization is reflected in the fact that the classical constitutive relations of<br />electrical elements are replaced by the fractional ones. The modification of<br />constitutive relations allows for taking into account the finite relaxation and<br />polarization time of dielectric material, as well as the creation of the magnetic<br />field, it also allows for taking into account the history of polarization and<br />magnetization processes. The topological generalization of the elementary<br />circuit of transmission line, in addition to the standard elements, introduces a<br />capacitor in the series branch, which models the effect of charge<br />accumulation along the transmission line, i.e., the finite relaxation time.</p>
67

Effects of dietary Garcinia kola supplementation and oxidative stress in isolated perfused rat hearts

Nyepetsi, Naledi Gape January 2014 (has links)
Thesis submitted in fulfilment of the requirements for the degree of Master of Technology: Biomedical Technology In the Faculty of Health and Wellness Sciences At the Cape Peninsula University of Technology Supervisors: Prof. Adriaan J Esterhuyse Dr Dirk J Bester Bellville January 2014 / Background: Oxidative stress and chronic inflammation contributes significantly to the pathogenesis of several ischaemic heart diseases, including atherosclerotic plaque rupture and myocardial infarction. It is widely demonstrated that ischaemia, followed by reperfusion, results in alterations of the mitochondrial and endothelial function through uncontrolled cascades of events characterized by free radical release and inflammation. Recent experimental evidence shows that modulation of inflammatory and antioxidant signaling mediators may determine the host outcome following myocardial ischaemia-reperfusion injury. Investigations from the past decade indicate that food supplements may play an important role in the prevention and management of chronic inflammatory diseases. Garcinia kola seeds are flavonoid rich nut from a tropical flowering, non-timber plant of the Guttiferae family. This plant is highly valued in several African cultures for its use in herbal medicine. Recently, the majority of experimental research has linked phytochemicals found in Garcinia kola nut, to its proposed beneficial effects in treatment and management of oxidative stress related-chronic diseases. Research performed in our laboratory demonstrated that kolaviron, a prominent Garcinia kola flavonoid extract, reduces myocardial apoptosis during ischaemia-reperfusion injury. Therefore, the aim of our current study was to determine the effects of Garcinia kola supplementation on cardiac inflammatory and antioxidant signaling pathways during ischaemia-reperfusion using a Wistar rat heart model. Materials and Methods: Male wistar rats were randomly divided into two groups: a control group receiving 2ml/kg corn oil and the experimental group receiving 100mg/kg Garcinia kola dissolved in corn oil, daily for 4 weeks. After the feeding period, blood samples were collected and lymphocytic DNA damage was analyzed using the alkaline comet assay. Furthermore, rat hearts were isolated and perfused with Krebs-Henseleit buffer on a working heart perfusion apparatus to measure myocardial functional parameters. Myocardial functional recovery was measured after 15 minutes global ischaemia followed by 25 minutes reperfusion. Hearts were freeze clamped at three different time points for myocardial cytokine concentration determinations using multiplex electrochemilunescent immunoassay. Nuclear factor kappa beta (NF- kβ), p38 mitogen activated protein kinases (p38 MAPK), protein kinase B/Akt (PKB/Akt), nitro-tyrosine, inducible nitric oxide (iNOS), cyclooxygenase-2 (COX-2), poly (adenosine-di-phosphate) ribose polymerase-1 (PARP-1) and caspase-3 expression and their phosphorylated forms (where applicable) were analyzed using the Western blot technique. Results: Dietary Garcinia kola supplementation significantly improved functional recovery when compared to the control group as reflected by the improved aortic output recovery (68.47 ± 6.16% versus 44.96 ± 7.00%; p<0.05). Our biochemical results supports the hypothesis that, dietary Garcinia kola supplementation modulates different cardiac proteins in terms of expression and activation at different time points when compared to the control group. We show that, before induction of ischaemia, Garcinia kola supplementation attenuates expression of inflammatory mediators and pro-apoptotic proteins when compared to the control group. The improved functional recovery was associated with a prompt inflammatory response, activation of PKB/Akt and attenuation of protein nitrosylation after 10 minutes of reperfusion. Modulation of NF-kβ and the p38 MAPK family proteins expression could have also played a significant role in myocardial functional recovery. Conclusion: We have shown that a 4 week period of dietary Garcinia kola supplementation at 100mg/kg daily improves cardiac functional recovery following ischaemia-reperfusion injury. We propose that dietary Garcinia kola supplementation protects cardiac myocytes from ischaemia-reperfusion induced oxidative stress through the induction of a prompt inflammatory response and controlled expression and/or activation of the, NF-kβ, PKB/Akt and p38 MAPK protein signaling pathways PARP-1 and caspase. Finally, we demonstrated that dietary Garcinia kola supplementation did not induce rat lymphocytic DNA damage when compared to the control group.
68

Effects of kolaviron–a Garcinia kola biflavonoid on biochemical and histological parameters in streptozotocin - induced diabetes and diabetic complications (nephrotoxicity and hepatotoxicity) in male Wistar rats

Ayepola, Omolola Rebecca January 2014 (has links)
Thesis submitted in fulfillment of the requirements for the Doctor of Technology: Biomedical Technology In the Faculty of Health and Wellness At the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY 2014 / Diabetes mellitus (DM) results in severe metabolic imbalances and pathological changes in many tissues. Chronic inflammation and oxidative stress have been implicated in the pathophysiology of diabetes mellitus. Garcinia kola (Family: Guttiferae) is a plant well known for its ample medicinal values. The seed of the plant also known as ‘bitter kola’ due to its bitter taste is used as a masticatory agent in traditional hospitality, cultural and social ceremonies in Africa. Kolaviron (KV) is a defatted ethanol extract from the seeds of Garcinia kola (GK). Kolaviron has been shown in experimental models of diseases to have numerous beneficial effects due to the presence of flavonoids (mainly Garcinia biflavonoid (GB)-1, GB-2 and kolaflavanone). However, there is paucity of information regarding the possible effect of kolaviron on inflammatory mediators and oxidative stress in diabetes mellitus. Therefore, this study was carried out to investigate the potential beneficial effects of kolaviron on antioxidant status, inflammatory mediators and apoptosis. Other biochemical and histological alterations in the blood, liver and kidney of streptozotocin-induced diabetic rats were also evaluated. A single intraperitoneal injection of freshly prepared solution of streptozotocin (50 mg/kg.b.wt.) in citrate buffer (0.1M, pH 4.5) was administered to overnight fasted rats for diabetes induction. Diabetes was confirmed by stable hyperglycemia (>18 mmol/l) in the tail blood glucose after 5 days of streptozotocin injection. Kolaviron (100 mg/kg b.wt.) was administered to diabetic rats (by gastric gavage) on the 6th day after the induction of diabetes and treatment continued for 6 weeks (5 times weekly). The effects on blood glucose, body weight, organ (liver and kidney) weight, serum biochemical parameters, oxidative status, inflammatory mediators and histology of the liver, kidney and pancreas were assessed. Kolaviron (KV) treatment lowered blood glucose in diabetic and normoglycemic rats and reduced glycated haemoglobin [HbA1C (%)]. Plasma insulin level was raised in diabetic rats treated with KV. Histomorphometric analysis of the pancreas revealed increased β-cell area of pancreatic islets of kolaviron-treated diabetic group. The indices of organ (liver and kidney) damage were increased in diabetic rats. However, KV treatment protected against liver and kidney damage. The characteristic features of diabetic dyslipidemia such as elevated serum triglyceride and cholesterol concentration which are major risk factors for cardiovascular disease were also significantly reduced in KV-treated diabetic rats. Alteration in antioxidant enzymes status was observed in the liver, kidney and blood (erythrocyte, plasma and serum) of diabetic rats. Lowered catalase (CAT) activity was observed in the liver and kidney of diabetic rats while KV treatment significantly (p < 0.05) elevated catalase activity in the liver and kidney. There was no significant change (p > 0.05) in erythrocyte catalase activity among all treatment groups. Erythrocyte of diabetic rats showed a marked reduction in the activity of superoxide dismutase (SOD) with no significant changes in liver and kidney SOD activity of diabetic rats compared to control whereas KV administration to rats markedly increased SOD activity. Glutathione peroxidase (GPX) activity was elevated in the erythrocyte and kidney of STZ-induced diabetic rats with no significant effect on liver GPX activity. KV treatment reversed the alteration in GPX activity in the kidney and erythrocyte. Level of reduced glutathione (GSH), a non-enzymatic antioxidant was decreased in the both liver and kidney of diabetic rats and treatment of diabetic rats with KV elevated GSH concentration in both tissues. Also, malondialdehyde (MDA), a marker of lipid peroxidation was elevated in the liver, kidney and plasma of diabetic rats and significantly (p < 0.05) lowered following KV treatment. Diabetes induction reduced the capacity of liver and kidney to absorb oxygen radicals as demonstrated by lowered oxygen radical absorbance capacity (ORAC) values. KV administration to normal and diabetic rats significantly increased ORAC values. Increased rate of apoptosis, a major cellular response to high glucose induced stress was observed in the renal and hepatic tissues of diabetic control rats. Kolaviron treatment of diabetic rats protected the liver and kidney against hyperglycemia-induced apoptosis and decreased the number of TUNEL positive cells A significant (p < 0.05) elevation of pro-inflammatory cytokines; monocyte chemoattractant protein (MCP-1), Interleukin-1β (IL-1β), IL-6 and tumor necrosis factor (TNF)-𝛂 was observed in the liver of diabetes rats. KV treatment lowered these inflammatory biomarkers. On the other hand, the kidney of diabetic rats showed elevated concentration of pro-inflammatory IL-1β with no significant effect on kidney TNF-𝛂. An increase in the serum concentration of MCP-1 and IL-1β was observed in the untreated diabetic rats while kolaviron treatment normalized the alteration in serum concentration of MCP-1, IL-1β and vascular endothelial growth factor (VEGF). In conclusion, persistent and chronic hyperglycemia promotes the generation of free radicals and inflammatory molecules which contributes to progressive development of micro- and macro vascular complications and multi-organ damage. Kolaviron demonstrated beneficial effects on markers of oxidative stress and inflammation in the diabetic rats and also promoted the survival and functional integrity of the liver and kidney.
69

Eurasian Arctic ice sheets in transitions:consequences for climate, environment and ocean circulation

Kaparulina, E. (Ekaterina) 16 January 2018 (has links)
Abstract In this Ph.D. thesis sediment cores from the central Arctic Ocean, southwestern Barents Sea and sediment exposures from the Kola Peninsula were investigated in order to reveal interactions between the late middle Pleistocene and late Pleistocene Arctic ice sheets, between Marine Isotope Stages 6 and 1 (MIS 6 and MIS 1). One of the main objectives of this work is to establish provenance areas for the sediments studied in the central Arctic, the southwestern (SW) Barents Sea and the Kola Peninsula, their transport mechanisms and through that their relationship to glaciations in the Arctic and to development in the Kola Peninsula during the late middle and late Pleistocene. Mineralogical and geochemical data from the core 96/12-1pc on the Lomonosov Ridge, central Arctic Ocean was studied to evaluate ice transport from circum-Arctic ice sheets and variability in sediment drainage systems associated with their decay. SW Barents Sea sediments contain important information on Late Glacial and Holocene sediment provenance characteristics in relation to ice flow patterns and ice rafting from different regional sectors. The studied SW Barents Sea sediment cores show that sediments were most likely derived from a combination of far-field Fennoscandian sources, local subcropping Mesozoic strata below the seafloor and sea ice transport. The investigation carried out on the Kola Peninsula indicates that the Eemian (MIS 5e) marine environment in the White Sea Basin and onshore coastal areas gradually changed into a glaciolacustrine environment during MIS 5d to MIS 5a. Subsequently, the Scandinavian Ice Sheet (SIS) covered the Kola Peninsula, most probably during MIS 4. The final deglaciation of the SIS on the Kola Peninsula took place, however, during the late Weichselian (MIS 2) between 16–12 ka. / Tiivistelmä Tässä väitöstutkimuksessa tutkittiin sedimenttikairanäytteitä keskeiseltä Jäämereltä ja Lounais-Barentsinmereltä sekä tarkasteltiin sedimenttiseurantoja Kuolan niemimaalla tarkoituksena selvittää myöhäisen keskipleistoseeni- ja myöhäispleistoseeniajan Arktisten jääkenttien keskinäiset vuorovaikutukset erityisesti merellisten isotooppivaiheiden 6 ja 1 (MIS 6 ja MIS 1) välillä. Tämän työn yhtenä päätavoitteena on määritellä sedimenttien lähdealueet keskeisellä Arktiksella, lounaisella Barentsinmerellä ja Kuolan niemimaalla, sedimenttien kuljetusmekanismit ja näiden perusteella riippuvuudet Arktisiin jäätiköihin ja Kuolan niemimaalla tapahtuneeseen myöhäiskeski- ja myöhäispleistoseenin kehitykseen. Mineraloginen ja geokemiallinen tieto Lomonosovin harjanteen kairauksesta 96/12-1pc, keskeisellä Jäämerellä on perusta arvioitaessa jääkuljetusmekanismeja ympäröiviltä sirkum-Arktisilta jäätiköiltä ja arvioitaessa valuma-alueiden osuutta suhteessa näiden jäätiköiden häviämiseen. Lounaisen Barentsinmeren sedimentit sisältävät tärkeätä tietoja viimeisen jäätiköitymisen loppuvaiheen ja holoseeni-ajan sedimenttien lähdealueista ja suhteista jäävirtauksiin ja jääkuljetukseen eri aluesektoreilta. Tutkitut Lounais-Barentsinmeren sedimentit osoittavat, että sedimentit olivat todennäköisimmin peräisin suhteellisen kaukaisilta Fennoscandian lähdealueilta, paikallisista mesotsoosista merenpohjan kerrostumista ja merijään kuljettamasta materiaalista. Kuolan niemimaalla tehty tutkimus osoittaa, että Eem-kauden (MIS 5e) meriympäristö Vienanmeren altaassa ja rannikkoalueilla vähitellen muuttui glaciolakustriseksi ympäristöksi MIS 5d:n ja MIS 5a:n välisenä aikana. Sen jälkeen Skandinavian jääkenttä (SIS) peitti Kuolan niemimaan, todennäköisimmin koko MIS:n 4 ajanjakson. SIS:n lopullinen deglasiaatio alkoi Kuolan niemimaalla kuitenkin myöhäisen Veiksel-jääkauden (MIS 2) aikana noin 16–12 ka sitten.
70

Návrh elektro-hydraulické soustavy pro ovládání příďového podvozku malého dopravního letounu / Proposal of electro-hydraulic control system for the nose gear of small transport aircraft

Vodička, Petr January 2017 (has links)
The diploma thesis is focused on design of electrohydraulic system for nose gear control on small civil airliners. First part consists of brief review of small civil airliners, nose gears and CS 23 restrictions relevant for the design. In practical part a typical small civil airliner is defined and kinematic of landing gear mechanisms is designed. Then the electrohydraulic system itself is designed and parameters of some components are suggested. The wheel steering mechanism is simulated and, in conclusion, the whole system is evaluated.

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