In der vorliegenden Arbeit wurden Schichten des Hochtemperatursupraleiters YBa2Cu3O7-δ (YBCO) untersucht, die epitaktisch mittels gepulster Laserabscheidung auf texturierten metallischen Templaten abgeschieden wurden. Dabei kamen ionenstrahltexturiertes ABAD-YSZ-Band und walztexturiertes NiW-Band zum Einsatz. Für Anwendungen solcher sogenannten Bandleiter ist die Fähigkeit zum Transport möglichst hoher kritischer Ströme Ic essentiell. Dies kann durch das Wachstum möglichst dicker Schichten, eine Verbesserung der Flussschlauchverankerung (Pinning), sowie die Reduzierung der durch Korngrenzen verursachten Stromlimitierung erreicht werden. Im ersten Teil der Arbeit wurden strukturelle und supraleitende Eigenschaften in bis zu 5 µm dicken YBCO-Schichten auf ABAD-YSZ-Band untersucht. Dazu wurden neben nicht-fremdphasendotierten (undotierten) YBCO-Schichten auch BaHfO3- und BaY(NbTa)O6-dotierte YBCO-Schichten herangezogen. Die Untersuchungen erfolgten mittels Röntgenbeugungs-methoden (XRD), Rasterelektronen- und Rasterkraftmikroskopie (REM, AFM), sowie resistiver und induktiver Methoden zur Bestimmung der Sprungtemperatur Tc und der kritischen Stromdichte Jc. Schichtdickenabhängige Messungen konnten u. a. zeigen, dass Ic in undotierten YBCO-Schichten bei einer Dicke oberhalb von 2,8 µm nicht weiter anstieg, während Ic in den dotierten Schichten bis zu einer Dicke von 5 µm nicht limitiert war. Darüber hinaus konnte in temperatur- und feldabhängigen Jc-Messungen ein verbessertes Pinningverhalten bei tiefen Temperaturen und in hohen äußeren Magnetfeldern gefunden werden. Mit Hilfe von transmissionselektronenmikroskopischen Untersuchungen (TEM) und Messungen der Jc-Anisotropie wurde zusätzlich ein Strukturschema herausgearbeitet, das eine Verknüpfung von Herstellungsparametern, Mikrostruktur und Pinningeigenschaften ermöglicht. Der zweite Teil befasste sich mit der Analyse der Mikrostruktur und der lokalen Textur von undotierten YBCO-Schichten auf ABAD-YSZ- und NiW-Band. Die lokale Textur wurde dabei mittels Rückstreuelektronenbeugung (EBSD) aufgelöst. Die Ergebnisse wurden mit orts-aufgelösten Magnetisierungsmessungen (Raster-Hall-Sonden-Mikroskopie) korreliert, mit denen der lokale Stromfluss untersucht werden kann. Auf beiden Templaten zeigte sich eine granulare Struktur, die durch gegeneinander verkippte bzw. verdrehte YBCO-Körner gekennzeichnet war. Während die granulare Struktur auf ABAD-YSZ-Band durch hauptsächlich in-plane missorientierte YBCO-Bereiche mit einem Durchmesser < 1 µm charakterisiert war, konnten auf NiW-Band hauptsächlich out-of-plane missorientierte Bereiche mit einer typischen Größe von 20-50 µm nachgewiesen werden. Auf NiW-Band hing die YBCO-Mikrostruktur und die Schärfe der lokalen Textur von der individuellen out-of-plane Missorientierung des darunter-liegenden NiW-Korns ab, was auf eine bereits im unbeschichteten NiW-Band vorhandene Facettierung zurückgeführt werden konnte. Zu deren Beschreibung wurde ein Facettenmodel entwickelt, das durch TEM-Untersuchungen bestätigt werden konnte. Abschließend wurde auf einkristallinen Substraten und auf ABAD-YSZ-Band ein homogener Stromfluss nachgewiesen, während die supraleitenden Eigenschaften in YBCO-Schichten auf NiW-Band von der lokalen Mikrostruktur und Textur bestimmt wurden. Damit konnte gezeigt werden, dass die globalen Eigenschaften der Bandleiter vom Zusammenspiel eines über Korngrenzen miteinander verbundenen Ensembles von Körnern mit individuellen Eigenschaften bestimmt werden.

Surgical site infection is responsible for 38 percent of reported infections after surgery. This infection increases mortality and treatment costs, and prolongs the hospitalization of patients. Bacteria-carrying particles are the main cause of surgical site infection and one of the main sources of these particles is skin fragments released from the surgical personnel during an ongoing surgery. Ventilation systems reduce the concentration of bacteria-carrying particles by supplying clean air in the operating room. The performance of operating room ventilation systems is affected by internal disruptions such as medical equipment, surgical lamps, number of staff and their behaviour during the surgery. Using computational fluid dynamics, this thesis investigates the airflow behaviour and distribution of the contamination in the operating room under the presence of various internal disruptions. In this regard, three common ventilation systems are considered: laminar airflow, turbulent mixing and temperature-controlled airflow ventilations. This study tries to overcome the weaknesses of the ventilation systems by providing sustainable solutions and continuously being in contact with design companies. It is common to use warming blankets to prevent reduction in the core body temperature of the patient during major surgeries. However, there is a major concern that these blankets disrupt the supplied airflow, which results in rising contaminant concentration. Most of the studies about warming blankets are clinical works and it is still not clear whether or not these blankets should be used. The results of the present study show that using warming blankets had no impact on increase of contamination level at the surgical zone. However, one common type of warming blanket – a forced-air warming blanket – can considerably increase the concentration of bacteria-carrying particles at the wound area if it becomes contaminated. The simulated results of the airflow field and particle tracking showed that the laminar airflow ventilation system was disturbed more easily by the local heat loads than overall heat loads in the operating room. Surgical lamps are considered as an obstacle in the supplied airflow path. These lamps create a stagnant area above the operating table and increase the contamination level. In this regard, a novel design of surgical lamp, a fan-mounted surgical lamp, was introduced to operating rooms.This device was used in the operating rooms equipped with laminar airflow and mixing ventilation system. The simulated results revealed that this lamp significantly reduced the contamination level at the operating table. Visualization techniques were adopted to teach and improve the understanding of surgical personnel about transmission of contaminated particles in operating rooms. Here, a virtual and augmented reality interface was used to visualize the impact of differences in ventilation principle, surgical staff constellation and work practice. / Infektioner relaterade till kirurgiskt ingrepp utgör 38 % av rapporterade infektioner efter operation. Dessa infektioner ökar dödligheten och behandlingskostnaderna samt förlänger patienternas sjukhusvistelse. Bakteriebärande partiklar är den främsta orsaken till infektion vid kirurgi. Huvudkällan till dessa partiklar är hudfragment som frigörs från kirurgisk personal under en pågående operation. Genom att tillföra ren luft via ventilationssystemet kan koncentrationen av baktebärande partiklar i operationssalen minskas. Ventilationssystemets förmåga att ventilera salen påverkas av föremål som stör luftströmmen, som exempel medicinsk utrustning, kirurgiska lampor samt av närvarande personal och deras beteende under operationen. Med avancerade numeriska strömningsberäkningar undersöks i denna avhandling luftflöden och fördelningen av föroreningar i operationssalen under inverkan av sådana störningar. Tre olika ventilationssystem inkluderas. Ett för laminärt luftflöde, ett för turbulent omblandning och ett för temperaturreglerad luftströmning. I studien kartläggs ventilationssystemens funktion och relevansen prövas i ett kontinuerligt samarbete med tillverkande industri. Användning av värmefiltar förekommer under större operationer för att hålla patientens kroppstemperatur stabil. Det finns emellertid en stor oro för att dessa filtar stör det tillförda luftflödet och därmed ökar föroreningsnivån. En vanlig typ av värmefilt med forcerad varmluft kan om den är förorenad avsevärt öka koncentrationen av bakteriebärande partiklar i sårområdet. De flesta undersökningar om värmande filtar är kliniska studier och det är fortfarande inte helt klarlagt i vilken mån och hur dessa filtar skall användas. Denna studie visar emellertid att användning av värmefiltar inte påverkar föroreningsnivån i den kirurgiska zonen. Gjorda datorsimuleringar av luftflödesfältet och partikelspårning visar att det laminära ventilationsflödet lättare störs av lokala värmebelastningarna än av generella värmebelastningar i operationssalen. Kirurgiska lampor betraktas som hinder i en planerad luftflödesväg. Lampor kan skapa en stillastående luftmassa ovanför operationsbordet och därmed öka föroreningsnivån. För detta introduceras en ny design av kirurgisk lampa, en fläktmonterad kirurgisk lampa för operationsrum, utrustade med laminärt luftflöde och omblandning. Simulerade resultat visar att denna nya kirurgiska lampa signifikant minskar föroreningsnivån vid operationsbordet. Visualiseringsteknik användes i denna studie för att förbättra förståelsen hos kirurgisk personal om hur förorenade partiklar kan spridas i operationssalen. Med ett virtuellt och förstärkt gränssnitt visualiserades föroreningshalter i rumsluften då olika typer av ventilationssystem användes. Visualiseringen visar också hur kirurgigruppens storlek och arbetsställning under operation påverkar spridningen av föroreningar. / <p>QC 20201103</p>

Utvecklingen av teknologin i dagens industrier förändras snabbt och för att bibehålla verksamhetens konkurrenskraft är det viktigt att förstå kundernas behov. Prognostisering är förväntat framtida behov baserad på historisk data. En prognos kan hjälpa ett företag med att planera och budgetera för framtida produktions- och distributions behov, samt fatta beslut om lagerhållning och inköp av råvaror. Syftet med studien är att undersöka framtida materialbehov med hjälp av prognostisering samt öka förståelsen samtidigt. Målet med studien är att få fram en metod för att utföra prognoser i ett affärssystem. De frågor studien kommer att besvara är “Hur kan användning av prognoser minska ledtider och bundet kapital?” &amp; “Hur kan affärssystemet SAP användas för prognoser av en specifik produktgrupp?”Genom en förstudie om ämnet och därefter en fallstudie hos Wexiödisk kommer informationen att tas. Studien består av primära källor i form av intervjuer och sekundära källor i form av dokumentinsamling. Resultaten studien kom fram till var bland annat transaktionskoder och dess användningsområde, förklaring och utvärdering av parametrarna tillhörande materialplanering 1-4 och prognos. Dessutom hur en grundläggande prognos kan utföras med historiska värden. Resultatet redovisar även skillnaden i bundet kapital med hjälp av prognostisering.Den generella slutsatsen från studien är att med en parameterlösning och arbetssätt för att utföra prognosen besvaras frågan “Hur kan affärssystemet SAP användas för prognoser av en specifik produktgrupp?”. Vidare förslag om forskning och optimering kring parametrarna ges även för att få en mer exakt slutgiltig prognos. / The development of technology in today's industries is changing rapidly and in order to maintain the competitiveness of the business it is important to understand the needs of the customers. Forecasting is expected future demand based on historical data. A forecast can help a company plan and budget for future production and distribution needs, as well as make decisions about stocking and purchasing raw materials.The purpose of the study is to investigate future material needs using forecasting and to gaina greater understanding at the same time. The goal of the study is to come up with a method for performing forecasts in a business system. The questions the study will answer are "How can the use of forecasts reduce lead times and tied up capital?" &amp; "How can the business system SAP be used for forecasts of a specific product group?"Through a preliminary study on the subject and then a case study at Wexiödisk, which the information will be taken from. The study consists of primary sources in the form of interviews and secondary sources in the form of document collection.The results of the study showed among other things, transaction codes and their area of use, explanation and evaluation of the parameters associated with MRP 1-4 and forecasting. Also, how a basic forecast can be performed using historical values. The result also reports the difference in tied up capital with the help of forecasting.The general conclusion of the study is that with a parameter solution and working method to perform the forecast, the question "How can the business system SAP be used for forecasts of a specific product group?" is answered. Further suggestions about research and optimization around the parameters are also given to get a more accurate final forecast.

[EN] This work has been developed within the framework of the Tourism Research Group of the Universidad Politécnica de Valencia. The main objective is to provide a model for a systematic analysis of the key elements that intervene in the process of determination of the Recreational Carrying Capacity for public use zones in Protected Areas. The proposed tool was deployed in the following cases study: Font Roja Natural Park (Ibi and Alcoi, in Alicante), Columbretes Islands Natural Reserve (in Castellón) and Albufera Natural Park (in Valencia). Considering the high volume of variables that take place in the determination and further management of the Recreational Carrying Capacity, it becomes highly difficult to elaborate a world-wide methodology. Nevertheless, this Thesis brings a general pattern applicable to practically every case with the necessary adaptations. On the other hand, this thesis arises the importance of considering the social aspects in the determination of the Recreational Carrying Capacity. In this sense, new concepts as psychological comfort of the users and visitors satisfaction are incorporated into the analysis with equal consideration as the ecological ones. It is also suggested that Recreational Carrying Capacity must be taken into account on the drawing up of the Protected Area Master Plans as a preventive tool for avoiding tourist impacts and guarantee users’ satisfaction. / [ES] Teniendo como marco de trabajo el desarrollado en el seno del Grupo de Investigación Aplicada al Turismo de la Universidad Politécnica de Valencia, la presente Tesis Doctoral tiene como objetivo principal aportar una sistemática orientada al análisis de los factores clave que intervienen en el proceso de determinación de la capacidad de carga recreativa para las áreas de uso público de los espacios protegidos. La herramienta de trabajo propuesta, se probó en tres casos de estudio: Parque Natural de la Font Roja (Ibi y Alcoi, Alicante), la Reserva Natural de las Islas Columbretes (Castellón) y el Parque Natural de l’Albufera de Valencia (Valencia). Considerando el volumen elevado de variables que intervienen en la determinación y posterior gestión de la capacidad de carga, es difícil elaborar una metodología de aplicación universal. En el presente trabajo se plantea, sin embargo, un esquema aplicable a todos los casos con las consiguientes adaptaciones que cada uno requiera. Por otro lado, se plantea la importancia de considerar los aspectos sociales en la determinación de la capacidad de carga de un sistema, sugiriéndose su incorporación, junto con los aspectos ecológicos tradicionalmente contemplados para el estudio de espacios protegidos y el diseño posterior de los correspondientes planes de gestión. En este sentido, se incorporan conceptos nuevos relacionados con la herramienta planteada como es el caso del confort psicológico de los usuarios y la satisfacción de los visitantes. / [CA] Tenint com a marc de treball el desenvolupat el sinus del Grup d’Investigació Aplicada al Turisme de la Universitat Politècnica de València, la present Tesi Doctoral té com objectiu principal aportar una sistemàtica orientada a l’anàlisi dels factors clau que intervenen al procés de determinació de la capacitat de càrrega recreativa per a les àrees d’ús públic dels espais protegits. L’eina de treball proposada, es va assajar amb tres casos d’estudi: Parc Natural de la Font Roja (Ibi i Alcoi, Alacant), la Reserva Natural de les Illes Columbretes (Castelló) i el Parc Natural de l’Albufera de València (València). Considerant l’elevat volum de variables que intervenen a la determinació i posterior gestió de la capacitat de càrrega, és difícil elaborar una metodologia d’aplicació universal. Al present treball es planteja un esquema aplicable a tots els casos amb les escaients adaptacions que cadascun requereix. D’altra banda, el planteja la importància de considerar els aspectes socials a la determinació de la capacitat de càrrega d’un sistema, suggerint-se la seva incorporació, junt amb aspectes ecològics tradicionalment considerats per a l’estudi d’espais protegits i el disseny posterior dels corresponents plans de gestió. En aquest sentit, s’incorporen nous conceptes relacionats amb l’eina plantejada com és el cas del confort psicològic dels usuaris i la satisfacció dels visitants. / Morant González, M. (2007). Desarrollo de un modelo para la determinación de la capacidad de carga recreativa y su aplicación a espacios naturales protegidos de la Comunidad Valenciana [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/131738

The main aim of this study was to classify and describe the plant communities in the home range of white rhinoceros in order to understand the animal seasonal foraging ecology. To provide a detailed habitat description, forty sample plots were stratified randomly. A TWINSPAN classification, refined by Braun-Blanquet procedures, was carried out on the Viewpoint section of the reserve. Ten plant communities, grouped into five major community types, were identified. The veld condition and ecological carrying capacity in these communities were measured, stating an abundance of food on long grass while the short grass equal the number of short grass feeders. A number of behavioural aspects such as activity data, home range utilization and dietary usage were examined. Statistical methods such as the Spearman rank-order correlation, Wilcoxon sign test and Student T-test were used on rhino data. The difference in usage of the home range during wet and dry seasons was insignificant. / Environmental Sciences / M.Sc. (Environmental Management)

Social sustainability provides a meaningful approach for industry practitioners wishing to establish a platform to engage communities within enterprise development. It can be said that sustainability requires much more than environmental and fiscal achievements and, with an increased awareness of issues such as equity and power sharing, more corporates are incorporating their strategies in line with social responsibility values. This study therefore takes a closer look at how the Table Mountain Aerial Cableway Company, integrates this important concept of social sustainability in its business practices. The tourism industry has in fact grown to such an extent that global economists estimate the progress of international growth at between three and six percent annually. However, this growth can only be measured when businesses take social responsibility factors into consideration. According to the UNWTO (2011, p 1) UN Secretary-General, Ban Ki-Moon, opened the Fourth UN Conference on Least Developed Countries stating that the majority of: “…least developed countries (LDCs) are rich in resources. All have young and vibrant populations. These men and women need decent jobs, education, training, so they can make the most of their country’s assets - minerals and other commodities, farmland, rich stores of biodiversity and tourism potential”. This study therefore focuses on current and future issues pertaining to socially sustainable tourism at the Table Mountain Aerial Cableway Company in Cape Town, South Africa. In addition, it presents solutions for reducing the negative impacts of tourism, whilst at the same time embracing the benefits of tourism for the area and its local communities. The outcome of the study found that the Table Mountain Aerial Cableway Company added little value to social responsibility objectives. The company has made a significant effort in marketing their product through the mass media. However, there is an overall corporate responsibility barrier. Much still needs to be done to ensure accountability for social responsibility issues, not just within this particular company, but also throughout the tourism industry. / Environmental Sciences / M. Sc. (Environmental Science)

The history of surgery is nearly as old as the human race. Control of wound infection has always been an essential part of any surgical procedure, and is still an important challenge in hospital operating rooms today. For patients undergoing surgery there is always a risk that they will develop some kind of postoperative complication. It is widely accepted that airborne bacteria reaching a surgical site are mainly staphylococci released from the skin flora of the surgical staff in the operating room and that even a small fraction of those particles can initiate a severe infection at the surgical site.  Wound infections not only impose a tremendous burden on healthcare resources but also pose a major threat to the patient. Hospital-acquired infection ranks amongst the leading causes of death within the surgical patient population. A broad knowledge and understanding of sources and transport mechanisms of infectious particles may provide valuable possibilities to control and minimize postoperative infections. This thesis contributes to finding solutions, through analysis of such mechanisms for a range of ventilation designs together with investigation of other factors that can influence spread of infection in hospitals, particularly in operating rooms. The aim of this work is to apply the techniques of computational fluid dynamics in order to provide better understanding of air distribution strategies that may contribute to infection control in operating room and ward environments of hospitals, so that levels of bacteria-carrying particles in the air can be reduced while thermal comfort and air quality are improved.  A range of airflow ventilation principles including fully mixed, laminar and hybrid strategies were studied. Airflow, particle and tracer gas simulations were performed to examine contaminant removal and air change effectiveness. A number of further influential parameters on the performance of airflow ventilation systems in operating rooms were examined and relevant measures for improvement were identified. It was found that airflow patterns within operating room environments ranged from laminar to transitional to turbulent flows. Regardless of ventilation system used, a combination of all airflow regimes under transient conditions could exist within the operating room area. This showed that applying a general model to map airflow field and contaminant distribution may result in substantial error and should be avoided. It was also shown that the amount of bacteria generated in an operating room could be minimized by reducing the number of personnel present. Infection-prone surgeries should be performed with as few personnel as possible. The initial source strength (amount of colony forming units that a person emits per unit time) of staff members can also be substantially reduced, by using clothing systems with high protective capacity. Results indicated that horizontal laminar airflow could be a good alternative to the frequently used vertical system. The horizontal airflow system is less sensitive to thermal plumes, easy to install and maintain, relatively cost-efficient and does not require modification of existing lighting systems. Above all, horizontal laminar airflow ventilation does not hinder surgeons who need to bend over the surgical site to get a good view of the operative field. The addition of a mobile ultra-clean exponential laminar airflow screen was also investigated as a complement to the main ventilation system in the operating room. It was concluded that this system could reduce the count of airborne particles carrying microorganisms if proper work practices were maintained by the surgical staff. A close collaboration and mutual understanding between ventilation experts and surgical staff would be a key factor in reducing infection rates. In addition, effective and frequent evaluation of bacteria levels for both new and existing ventilation systems would also be important. / Tidigt i mänsklighetens utveckling har kirurgin funnits med i bilden. Hantering av infektioner har genom tiderna varit en oundviklig del av alla kirurgiska ingrepp, och finns kvar ännu idag som en viktig utmaning i operationssalar på sjukhus. För patienter som genomgår kirurgi finns alltid en risk att de efter ingreppet utvecklar någon behandlingsrelaterad komplikation. Allmänt accepterat är att de luftburna bakterier som når operationsområdet huvudsakligen består av stafylokocker frigjorda från hudfloran av operationspersonalen i operationssalen, och att endast en liten del av dessa partiklar behövs för att initiera en allvarlig infektion i det behandlade området. Sårinfektioner innebär inte bara en enorm börda för hälso- och sjukvårdsresurser, utan utgör också en betydande risk för patienten. På sjukhus förvärvad infektion finns bland de främsta dödsorsakerna i kirurgiska patientgrupper.. En bred kunskap och förståelse av spridningsmekanismer och källor till infektionsspridande partiklar kan ge värdefulla möjligheter att kontrollera och minimera postoperativa infektioner. Denna avhandling bidrar till lösningar genom analys av en rad olika ventilationssystem tillsammans med undersökning av andra faktörer som kan påverka infektionsspridningen på sjukhus, främst i operationssalar. Syftet med arbetet är att med hjälp av CFD-teknik (Computational Fluid Dynamics) få bättre förståelse för olika luftspridningsmekanismers betydelse vid ventilation av operationssalar och vårdinrättningar på sjukhus, så att halten av bacteriebärande partiklar i luften kan minskas samtidigt som termisk komfort och luftkvalité förbättras.  Flera luftflödesprinciper för ventilation inklusive omblandade strömning, riktad (laminär) strömning och hybridstrategier har studerats. Simuleringar av luft-, partikel- och spårgasflöden gjordes för alla fallstudier för att undersöka partikelevakuering och luftomsättning i rummet. Flera viktiga parametrar som påverkar detta undersöktes och relevanta förbättringar  föreslås i samarbete med industrin. Av resultaten framgår att mängden genererade bakterier i en operationssal  kan begränsas genom att minska antalet personer i operationsteamet. Infektionsbenägna operationer skall utföras med så lite personal som möjligt. Den initiala källstyrkan (mängden kolonibildande enheter som en person avger per tidsenhet) från operationsteamet kan avsevärt minskas om högskyddande kläder används. Av resultaten framgår också att ett horisontellt (laminärt) luftflöde kan vara ett bra alternativ till det ofta använda vertikala luftflödet. Ett horisontellt luftflöde är mindre känsligt för termisk påverkan från omgivningen, enkelt att installera och underhålla, relativt kostnadseffektivt och kräver vanligen ingen förändring av befintlig belysningsarmatur. Framför allt begränsar inte denna ventilationsprincip kirurgernas rörelsemönster. De kan luta kroppen över operationsområdet utan att hindra luftflödet. En flyttbar flexibel skärm för horisontell spridning av ultraren ventilationsluft i tillägg till ordinarie ventilation undersöktes också. Man fann att denna typ av tilläggsventilation kan minska antalet luftburna partiklar som bär mikroorganismer om operationspersonalen följer en strikt arbetsordning. Bra samarbete och förståelse mellan ventilationsexperter och operationsteamet på sjukhuset är nyckeln till att få ner infektionsfrekvensen. Det är också viktigt med effektiva och frekventa utvarderingar av bakteriehalten i luften, för såväl nya  som befintliga ventilationssystem. / <p>QC 20160129</p>

Main extrinsic and intrinsic modifiers factors of crack growth rate in AA7050-T7451 were assessed in order to provide tools for aeronautical structures designers. These tools cover most necessary information to project aircraft\'s structures using the studied alloy, under damage tolerance philosophy. The experimental methodology consisted of use CT specimens, on TL and LT rolling direction to test its behavior under different conditions of stress ratio, force waveform, and the environment. The stress ratio values were 0.1 and 0.5, the force waveform used were sine and trapezoidal or Dwell under normal air laboratory conditions and salt fog 3.5%NaCl weight in order to simulate the marine environment. In Dwell tests, results were checked with the electrical potential drop technique (DCPD) in addition to the crack opening displacement (COD) method. Using the Walker coefficients, calculated on the present research, could be projected accurately the crack propagation behavior on Paris region and do fatigue life predictions using da/dN and S-N diagrams for different stress ratio values. The corrosion environment increases both crack growth rate and &Delta;Kth due to oxides formation on the crack path that generates a crack closure effect. Dwell carrying makes decrease the crack growth rate by decreasing the slope of the Paris line on log (da/dN) versus log (&Delta;K) curve, instead of shifting down the line as occurs on titanium alloys. Rolling direction change from LT to TL increase the FCG rate in both threshold and Paris region, where the rate change use to be small. / Os principais fatores modificadores extrínsecos e intrínsecos da taxa de propagação de trincas na liga AA7050-T7451 foram avaliados para fornecer subsídios para projetistas de estruturas aeronáuticas, com base na filosofía de tolerância ao dano. A metodologia experimental consistiu em ensaiar corpos de prova do tipo compact tension (CT) da liga nas direções de laminação TL e LT, para verificar seu comportamento sob diferentes razões de tensões, forma de onda e condição ambiente. Os valores de razão de tensão estudados foram 0,1 e 0,5, as formas de onda foram senoidal e trapezoidal ou de Dwell, em condições normais de laboratório, ao ar, e névoa salina 3,5% NaCl, em massa, para simular um ambiente marinho. No caso dos ensaios Dwell, os resultados foram conferidos pelo método de queda de potencial eléctrico (QPE), além do método de flexibilidade elástica. Usando os coeficientes de Walker calculados a partir dos resultados obtidos, pôde-se projetar com precisão o comportamento da propagação de trinca na região de Paris e prever a vida em fadiga usando os diagramas da/dN e S-N para diferentes valores da razão de tensões. O ambiente corrosivo aumenta tanto a taxa de propagação de trinca, quanto o valor de &Delta;Kth por causa da formação de óxidos na trajetória da trinca, que geram um efeito de fechamento sobre a mesma. Quanto à forma de onda, verificou-se que o carregamento Dwell diminui a taxa de propagação de trinca, diminuindo a inclinação das curvas log (da/dN) versus log (&Delta;K) na região de Paris, ao invés de deslocá-la paralelamente como ocorre com ligas de titânio. A mudança da direção de laminação de LT para TL aumenta a taxa de propagação de trinca por fadiga (PTF) tanto na região de threshold, quanto na região de Paris, onde a mudança de taxa é pequena.

Made available in DSpace on 2016-04-26T18:16:22Z (GMT). No. of bitstreams: 1 Fatima Daltro de Castro Correia.pdf: 981156 bytes, checksum: c066fd1d35e52db7caca7f986cb0bf9e (MD5) Previous issue date: 2007-09-11 / The increase of the images media exposition of wheels chair bodies promotes the impression to collaborate for the social inclusion of the body that we nominate deficient. However, the action of the nominations consecrated for the press, as of pcd (person with deficiency), operates exactly in the contrary direction, exposing the deficiency, transforming it into a stigma. The images of wheels chair bodies that are spreadon media are always associates to the question of the overcoming of limits, tying those bodies only to the values in circulation in the sport world. The prominence that the Paraolimpics Games occupies in the media inserts there, in the consolidation of the boarding of these bodies with images that congeal around an uniform way of the deficiencies in an only niche, delimited for the adopted concept of efficiency/productivity. A critical reflection regarding this situation becomes necessary to be able to deal with the dance that this body practises outside the narrow limits imposed for this stigma mechanism. For this, we here adopt the Theory Corpomedia (Katz & Greiner), with which if it presents the hypothesis of that the wheels chair body dancer is a complex system and able to breach with the perverse speech that the frozen images produce. The concept of corpomedia, formulated from the study of the communication between body, and its environments, favor the agreement of the paper that the media exploration has when it congeals the images that produce around the deficiency and not of the deficient one with its singularities. The methodology contemplates a Study of Case, Judite wants to cry, but it does not get it! , created for the wheels chair dancer Edu Oliveira; interviews aiming qualitative research; critical analysis of these interviews, carried through after the presentation of the spectacle in two different cities (Salvador and Votorantim); bibliographical revision of the subject of the deficient body; video registers. The bibliographical research allowed a brief historical panoramic sketch of the access of the wheels chair bodies to the world of dance and its social implications. Conclusion is that that the wheels chair dancer is cultural and biologically implied in a system of construction of images that associates him with a poor body and that they feed who it cognitivaly, with ominous consequences for the process of its social inclusion. From there the urgency in promoting actions that can breach with the media action in course. This is the role for the dance in wheels chair has and, to accomplish it, cannot be remained based in the criteria of the sport. The dance in wheels chair needs to discover its poetical, therefore they are who potencializes an effective social insertion / O aumento da exposição midiática de imagens de corpos cadeirantes promove a impressão de colaborar para a inclusão social do corpo que nomeamos de deficiente. Todavia, a ação das nomeações consagradas pela imprensa, como a de pcd (pessoa com deficiência), opera justamente no sentido contrário, midiatizando a deficiência, transformando-a em um estigma. As imagens de corpos cadeirantes que ganham divulgação estão sempre associadas à questão da superação de limites, vinculando aqueles corpos somente aos valores em circulação no mundo do desporto. O destaque que a Paraolimpíada ocupa na mídia se insere aí, na consolidação da abordagem desses corpos com imagens que se congelam em torno de uma uniformização das deficiências em um nicho único, delimitado pelo conceito de eficiência/produtividade adotado. Faz-se necessária uma reflexão crítica a respeito dessa situação para poder tratar da dança que esse corpo pratica fora dos estreitos limites impostos por esse mecanismo estigmatizador. Para isso, aqui se adota a Teoria Corpomídia (Katz & Greiner), com a qual se apresenta a hipótese de que o corpo do dançarino cadeirante é um sistema complexo e apto a romper com o discurso perverso que as imagens congeladas produzem. O conceito de corpomídia, formulado a partir do estudo da comunicação entre corpo, e seus ambientes, favorece o entendimento do papel que a exploração midiática tem quando congela as imagens que produz em torno da deficiência e não do deficiente com suas singularidades. A metodologia contempla um Estudo de Caso, o do espetáculo Judite quer chorar, mas não consegue! , criado pelo dançarino cadeirante Edu Oliveira; entrevistas com fins de pesquisa qualitativa; análise crítica dessas entrevistas, realizadas após a apresentação do espetáculo em duas cidades diferentes (Salvador e Votorantim); revisão bibliográfica do tema do corpo deficiente; registros em vídeo. A pesquisa bibliográfica permitiu um breve esboço panorâmico/ histórico do acesso dos cadeirantes ao mundo da dança e suas implicações sociais. Concluiu-se que o dançarino cadeirante é cultural e biologicamente implicado em um sistema de construção de imagens que o associam ao corpo coitadinho e que são elas que o alimentam cognitivamente, com conseqüências nefastas para o processo de sua inclusão social. Daí a urgência em promover ações que possam romper com a ação midiática em curso. É esse o papel que a dança em cadeira de rodas tem e, para desempenhá-lo, não pode se manter pautada pelos critérios do desporto. A dança em cadeira de rodas precisa descobrir as suas poéticas, pois são elas que potencializam uma inserção social efetiva

Although it offers a wide variety of interesting properties such as fire resistance or durability, stainless steel has been used in limited amount in structures. It is a known fact that the design rules don't properly account for the additional benefits of stainless steel properties and are largely based on the specifications for carbon steel. Indeed, a number of similarities exist between stainless steel and ordinary carbon steel but there is sufficient differences to afford a specific treatment in design standards. And since stainless steel is an expensive material, it is important to accurately predict the resistance of structural members. The present research work is dedicated to the study of cold-formed stainless steel profiles. It actually follows the life of a stainless steel construction element and falls on three fundamental topics: the material behavior, the through-thickness residual stress distribution and mechanical enhancement due to the cold-forming process and, last, the strength of concentrically compressed thin-walled columns. Firstly, several constitutive models are characterized such as Teodosiu-Hu's micro-structural based hardening model, capable of predicting the behavior of the studied stainless steel grade submitted to biaxial loading causing plastic strain. This model accounts for the nonlinear hardening behavior, the anisotropy, the Bauschinger effect and more complex behavior such as the observed work-hardening stagnation under reversed deformation at large strains. For this purpose, a collection of tests is carried out including multiaxial tests such as tensile-shear tests and successive simple shear tests and plane-strain tests. Secondly, the effects of the forming process on the mechanical properties are studied. To begin with, on the basis of the constitutive models developed previously, an analytical method that calculates the biaxial residual stress distribution in the walls and in the corners of cold-formed profiles is established. Based on the conclusions drawn from this theoretical analysis, a new formula for the evaluation of the actual mechanical properties is established. This formula is not restricted to a single alloy or type of cross-section. Current design standards are then used to calculate the strength of lipped-channel section columns failing by combined distortional and overall flexural-torsional buckling and the results are compared to tests. Indeed, full-scale tests on cold-formed stainless steel lipped channel section columns were achieved in the Structures Laboratory of the University of Liège. And, once verified against the test results, finite element models were used to generate additional results when necessary. The author then presents a new Direct Strength Method taking into account this phenomenon. Finally, a wide amount of reference results are gathered from the literature, without limiting oneself to any kind of cross-section or stainless steel grade. This database is used to propose an improved formulation for the design of stainless steel thin-walled section columns failing by distortion, local or combination of local and overall buckling in the low slenderness range.