[EN] The combination of different materials to form a single structural member to take profit of their individual good characteristics is a successfully established practice in building industry. In concrete filled tubular columns (CFT) the combined action of steel and concrete results in many positive attributes at ambient temperature: high load-bearing capacity with smaller cross-section size, aesthetics, high stiffness and ductility and reduced construction cost. In the last decades, the use of CFT columns in building industry, especially in high-rise buildings, has increased not only because of their positive characteristics at room temperature, but also for their inherent high fire resistance. Besides, CFT sections are greatly versatile given that they admit different types of concrete infill such as plain concrete, bar-reinforced concrete or fiber reinforced concrete; and also a wide variety of shapes. Although the more commonly used shapes are circular, and rectangular, new configurations and shapes are continuously appearing together with innovative materials. The ambient temperature behavior of CFT columns has been deeply studied and, in turn, the investigations dealing with their fire behavior have increased. For its structural analysis, the column can be considered as an isolated member or as a column integrated in a structure interacting with other structural members. The review of the state of the art in the area of CFT columns in fire carried out in the framework of this thesis has pointed out that most works cover the fire response of isolated members and that the existing studies on columns within frames differ in their proposals and conclusions. In this thesis, the fire response of CFT columns is analyzed by means of a fiber beam element model. First, a realistic cross-sectional thermal model is implemented to be integrated in the thermo-mechanical model developed whose accuracy is validated against experimental results after its calibration. Parametric studies are carried out with the aim of investigating the main factors affecting the problem and developing a simple calculation method based on Eurocode 4 and using the concept of equivalent concrete core cross-section. Finally, given the reduced computational cost of the fiber model, the effects of axial and rotational restraint in the fire response of CFT columns are investigated by integrating the heated CFT column within a frame. A parametric analysis is performed in order to draw conclusions about this interaction and contrast the current code provisions. The scope of this thesis is limited to circular CFT columns subjected to concentric axial loads. / [ES] Combinar diferentes materiales en un único elemento estructural para aprovechar las fortalezas individuales de cada uno es una práctica consolidada con éxito en el sector de la construcción. En los pilares tubulares de acero rellenos de hormigón (CFT) la acción conjunta del acero y el hormigón presenta muy buenas cualidades a temperatura ambiente: alta capacidad de carga con secciones pequeñas, buena apariencia, alta rigidez y ductilidad y bajo coste de puesta en obra. En las últimas décadas, el uso de pilares CFT en el sector de la construcción, especialmente en edificios de gran altura, ha aumentado no solo debido a sus buenas características a temperatura ambiente sino también por su inherente alta resistencia al fuego. Además, las secciones de pilares CFT son muy versátiles ya que admiten diferentes tipos de relleno, como hormigón en masa, con armaduras o reforzado con fibras; y también una amplia variedad de formas. Aunque los perfiles tubulares más usados son los circulares y rectangulares, nuevas configuraciones están continuamente en desarrollo junto con nuevos materiales. El comportamiento de los pilares CFT a temperatura ambiente ha sido ampliamente estudiado y, a su vez, las investigaciones sobre su comportamiento a fuego han aumentado. Para su análisis estructural, el pilar puede ser considerado como un elemento aislado o como un elemento integrado en una estructura que interactúa con otros elementos estructurales. La revisión del estado del arte en el área de los pilares CFT sometidos a fuego llevado a cabo en el marco de esta tesis ha puesto de manifiesto que la mayoría de los trabajos cubren la respuesta a fuego de elementos aislados y que los estudios existentes sobre pilares en estructuras difieren en sus propuestas y conclusiones. En esta tesis, la respuesta a fuego de pilares CFT se analiza por medio de un modelo de elementos viga con integración por fibras. En primer lugar, se implementa un modelo térmico realista para ser integrado en el modelo termo-mecánico desarrollado cuya precisión se valida con resultados experimentales después de ser calibrado. Un estudio paramétrico se lleva a cabo con el objeto de estudiar los principales factores que afectan al problema y desarrollar un modelo simplificado de cálculo basado en el Eurocódigo 4 Parte 1-1 y que emplea el concepto de sección equivalente del núcleo de hormigón. Finalmente, dado el reducido coste computacional del modelo de fibras, se investigan los efectos de la restricción axial y rotacional en la respuesta frente al fuego de los pilares CFT integrando la columna expuesta a fuego dentro de una subestructura. Se ejecuta un estudio paramétrico para extraer conclusiones sobre esta interacción y contrastar las prescripciones de la normativa actual. El alcance de esta tesis queda limitado a pilares CFT sin protección externa, de sección circular y sometidos a carga axial centrada. / [CA] Combinar distints materials en un únic membre estructural per a aprofitar les fortaleses individuals de cada u és una pràctica consolidada amb èxit en el sector de la construcció. En els pilars tubulars d'acer omplerts de formigó (CFT) l'acció conjunta de l'acer i el formigó presenta molt bones qualitats a temperatura ambient: alta capacitat de càrrega amb seccions xicotetes, bona aparença, alta rigidesa i ductilitat i baix cost de posada en obra. En les últimes dècades, l'ús de pilars CFT en el sector de la construcció, especialment en edificis de gran altura, ha augmentat no sols degut a les seues bones característiques a temperatura ambient, sinó també per la seua inherent alta resistència al foc. A més, les seccions de pilars CFT són molt versàtils, doncs admeten distints tipus de farcit, com formigó en massa, amb armadures o reforçat amb fibres; i també una àmplia varietat de formes. Encara que els perfils tubulars més usats són els circulars i rectangulars, noves configuracions estan contínuament en desenvolupament junt amb nous materials. El comportament dels pilars CFT a temperatura ambient ha sigut àmpliament estudiat i, al mateix temps, les investigacions sobre el seu comportament a foc han augmentat. Per a la seua anàlisi estructural, el pilar pot ser considerat com un element aïllat o com un element integrat en una estructura que interactua amb altres elements estructurals. La revisió de l'estat de l'art en l'àrea dels pilars CFT sotmesos a foc, duta a terme en el marc d'aquesta tesi, ha posat de manifest que la majoria dels treballs cobreixen la resposta a foc d'elements aïllats, i que els estudis existents sobre pilars en estructures difereixen en les seues propostes i conclusions. En aquesta tesi, la resposta a foc de pilars CFT s'analitza mitjançant un model d'elements biga amb integració per fibres. En primer lloc, s'implementa un model tèrmic realista per a ser integrat en el model termo-mecànic desenvolupat, i la seua precisió es valida amb resultats experimentals desprès de ser calibrat. Un estudi paramètric es du a terme amb l'objectiu d'estudiar els principals factors que afecten al problema i desenvolupar un model simplificat de càlcul basat en l'Eurocodi 4, Part 1-1 i que empra el concepte de secció equivalent del nucli de formigó. Finalment, tenint en compte el reduït cost computacional del model de fibres, s'investiguen els efectes de les restriccions axial i rotacional en la resposta a foc dels pilars CFT integrant la columna exposada a foc dins d'una subestructura. Un estudi paramètric s'executa per a obtenir conclusions sobre aquesta interacció i contrastar les prescripcions de la normativa actual. L'abast d'aquesta tesi queda limitat a pilars CFT sense protecció externa, de secció circular i sotmesos a càrrega axial centrada. / Ibáñez Usach, C. (2016). FIRE RESPONSE ANALYSIS OF CIRCULAR CONCRETE FILLED TUBULAR COLUMNS AND THE EFFECTS OF AXIAL AND ROTATIONAL RESTRAINTS [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/60150 / TESIS / Premios Extraordinarios de tesis doctorales

Le recours aux contentions physiques auprès des personnes âgées hospitalisées demeure une problématique malgré l'abondance d'écrits scientifiques sur la nécessité d'en réduire l'usage pour la sécurité et le maintien de la dignité des patients, notamment par l’utilisation des mesures alternatives. Les infirmières, qui sont parmi les professionnels de la santé qui ont la responsabilité d'en déterminer l'utilisation et la surveillance auprès d'aînés, se perçoivent comme étant peu formées sur le sujet. Bien que diverses interventions éducatives aient été mises en place pour tenter d'en réduire l'utilisation, leur efficacité sur les changements de pratique des infirmières demeure limitée. Par ailleurs, des interventions éducatives actives et engageantes, telle qu'une intervention de pratique réflexive, seraient pertinentes à explorer puisqu'elles semblent soutenir le développement professionnel des infirmières et l'amélioration des pratiques cliniques. Une étude pilote à devis mixte a permis de mettre à l'essai une intervention de pratique réflexive portant sur l’utilisation des contentions physiques auprès de huit infirmières d'un centre hospitalier universitaire et d'en évaluer l'acceptabilité, la faisabilité ainsi que les retombées. Les données collectées au moyen de questionnaires, de journaux réflexifs (infirmières participantes), d’un journal de bord (étudiante-chercheuse) et de groupes de discussion focalisée ont été analysées selon la méthode d’analyse thématique de Paillé et Mucchielli ainsi que de tests de Student. Les résultats de cette étude suggèrent qu’une intervention de pratique réflexive est acceptable et faisable auprès des infirmières, en plus d’améliorer leurs connaissances et favoriser leur réflexion quant à leurs attitudes et leur pratique en lien avec l’utilisation des contentions physiques auprès des personnes âgées hospitalisées. Cette étude a permis de relever les forces et les pistes d’amélioration de l’intervention. De nouvelles études portant sur l’évaluation des effets d’une intervention de pratique réflexive sur l’amélioration des pratiques cliniques des infirmières au regard de l’utilisation de la contention seraient pertinentes à mener. / The use of physical restraints on hospitalized elderly persons remains a concern despite the abundance of scientific literature emphasizing the need to reduce their use for the safety and dignity of patients through the implementation of alternative measures. Nurses, who are among the healthcare professionals responsible for determining the use and monitoring of restraints, perceive themselves as poorly trained on the subject. Although various educational interventions have been implemented to try to reduce their use, their effectiveness in changing nurses' practices remains limited. Moreover, active and engaging educational interventions, such as a reflective practice intervention, would be relevant to explore, as they appear to support nurses' professional development and the improvement of their clinical practices. A mixed-design pilot study was conducted to test a reflective practice intervention on the use of physical restraints with eight nurses from a university hospital and to assess its acceptability, feasibility, and outcomes. Data were collected through questionnaires, reflective journals (from participating nurses), field notes (from the student-researcher) and focused groups, and were analyzed using Paillé and Mucchielli's thematic analysis method as well as Student's t-tests. The results of this study suggest that a reflective practice intervention is acceptable and feasible among nurses, in addition to enhancing their knowledge and encouraging reflection on their attitudes and practices related to the use of physical restraints among hospitalized elderly. This study identified strengths and avenues for improvement in the intervention. Further studies evaluating the effects of a reflective practice intervention would be relevant.

Unplanned extubation is premature removal of endotracheal tube, is an adverse event; which can either, be accidental during a nursing procedure or self deliberate by the patient. The AACN Synergy Model for Patient Care was used as conceptual model for this study. A retrospective descriptive design revealed that over a period of two years, 327 patients admitted to the intensive care unit require intubation of which 40.4% were self-deliberate extubation and 59.4% accidental extubation. Of the accidental extubated patients, 29.8% had physical restrains, 57.6% received sedation, 43.9% had analgesic infusion and 38.9% were on neuromuscular blockade. A means Glasco Coma Scale was 9.4 and 56% of the patients were reported as being. Most patients (89.9%) required re-intubation. The findings also revealed that 49.1% of the nurses who cared for the patients when the extubation occured had one patient at the time. Also, 84.2% of nurses had 0-6 years of nursing experience and 74% of nurses had less than five years of ICU experience. / Health Studies / M.A. (Health Studies)

A synopsis of the importance and the nature of reading serve as the point of departure for this study. The pupils involved are learning restrained as well as A comprehensive reading problem analysis table, compiled for analysis of individual reading problems, facilitates identification of the remedial reading areas, as well as the underlying subskills causing the problems to be accommodated in remedial reading. A control chart, developed for recording the information concerning the pupil's reading problem area and underlying subskills, facilitates compilation of an integrated remedial reading programme. Existing exercises, selected from the works of various authors and adapted, provide guidelines and exercises for particular remedial reading areas. These guidelines serve as a point of departure for the compilation of a specific remedial reading programme for a particular pupil with reading problems. Two case studies elucidate how a remedial reading programme can be compiled according to the pupil's background, reading problems and inadequacies in the underlying subskills. Group A learning disabled pupils although learning disabled pupils in Group B and C can also be involved. The total reading process is illustrated by means of a reading model. The two main components, namely, word identification and comprehension, form the basis of this study. The different subcategories featuring in each component are highlighted. This model serves as a framework for the diagnosis and remediation of reading problems. A teaching model is used to illustrate the complexity of teaching. The factors ( within the teaching model are indicated, as well as the ways they may serve when reading is taught. The reduction and choice of reading content for a specific pupil are set out as important aspects to be taken into consideration in reading remediation. Determining each pupil's reading levels, namely, his/her independent level, instructional level and frustrational level, enables the teacher to choose the appropriate reading material. / Teacher Education / D. Ed. (Orthopedagogics)

This thesis deals with the selected vertical restraints on competition that occur in the sector of e-commerce, namely resale price maintenance, dual pricing and most-favoured-nation clauses. The thesis raises the research question what stance the European Commission, the Court of Justice of the European Union, and particularly national competition authorities and courts of the Federal Republic of Germany, the French Republic, the United Kingdom of Great Britain and Northern Ireland, the Italian Republic, the Kingdom of the Netherlands and the Kingdom of Sweden take to the above-mentioned practices. The decisions of the authorities are considered in terms of their degree of strictness towards the vertical restraints in question. From a systematic point of view, the thesis is divided into eight chapters. Its subject, basic questions, aims and methods used are outlined in the introductory chapter. The second chapter, which deals with the concept of e-commerce, mainly provides the definition of the scope of the sector under consideration from a material point of view. The third chapter analyses the results of the European Commission's inquiry into the e-commerce sector, especially its conclusions on the functioning of the sector, its features and trends in this sector, particularly with regard to their...

INTRODUÇÃO: A instabilidade multiligamentar do joelho, normalmente, é provocada por um trauma que determina sua luxação, um evento pouco frequente, mas, que pode trazer sequelas devastadoras. Mesmo com o tratamento cirúrgico preconizado é alto o índice de complicações. A mobilização precoce no pósoperatório provoca afrouxamento dos ligamentos reconstruídos, o que leva à instabilidade residual. A imobilização melhora a estabilidade, mas provoca dor e rigidez. Este trabalho tem o objetivo de avaliar se o uso do fixador externo articulado proporciona melhora na mobilidade, estabilidade e na função subjetiva de pacientes submetidos à reconstrução ligamentar. MÉTODOS: Neste ensaio clínico randomizado com grupos paralelos, 33 pacientes do ambulatório do Instituto de Ortopedia e Traumatologia do Hospital das Clínicas da Universidade de São Paulo com mais que 3 semanas de lesão dos ligamentos cruzados anterior e posterior associado à lesão de ligamento colateral fibular e/ ou ligamento colateral tibial foram submetidos à cirurgia de reconstrução multiligamentar, após alocação cega aleatória ao grupo 0 - controle (18 pacientes), com órtese rígida ou ao grupo 1 - fixador externo articulado por 6 semanas (15 pacientes), no período entre novembro de 2010 e novembro de 2013. Após seguimento mínimo de um ano de pós-operatório, a estabilidade dos ligamentos reconstruídos foi avaliada ao exame físico, foram mensurados os déficits de extensão e de flexão residual em relação ao joelho contralateral não acometido e foi aplicado o questionário específico para sintomas do joelho de Lysholm. RESULTADOS: Não houve diferença na avaliação da estabilidade articular nem na extensão entre os grupos. No grupo 1, o déficit de flexão passiva foi menor (4,8º +- 5,4º contra 18,2 +- 14,8º, p < 0,05) com mais pacientes, obtendo déficit de flexão considerado normal, de até 5º (64% contra 18%, p < 0,05) e com classificação excelente ou boa no questionário de Lysholm (73% contra 35%, p < 0,05). CONCLUSÕES: Comparado ao protocolo de reabilitação com órtese rígida removível, o uso do fixador externo articulado no tratamento cirúrgico das lesões multiligamentares do joelho proporciona os mesmos resultados de estabilidade ligamentar, aumenta a amplitude de movimento final, com manutenção da extensão e redução do déficit de flexão e proporciona melhores resultados funcionais / INTRODUCTION: Multiligament knee instability is normally caused by a trauma which results in its dislocation, an infrequent event, but one which can have devastating aftereffects. Even with the recommended surgical treatment the rate of complications is high. Early post-operative mobilization provokes loosening of the reconstructed ligaments, which leads to residual instability. Immobilization improves the stability, but causes pain and stiffness. This study aims to assess whether the use of an articulated external fixator provides improvements in the mobility, stability and the subjective function of the patients submitted to ligament reconstruction. METHODS: In this randomized clinical trial with parallel groups, 33 patients of the outpatient clinic of the Institute of Orthopaedics and Traumatology of the Hospital das Clínicas of the University of Sao Paulo with more than 3 weeks of injury to the anterior cruciate ligaments and the posterior cruciate ligaments associated with injury to the fibular collateral ligament and/or medial collateral ligament, were submitted to multiligament reconstruction surgery, after blind random allocation to either: Group 0 - control (18 patients), with rigid bracing, or to Group 1 - articulated external fixator for 6 weeks (15 patients), in the period from November, 2010 to November 2013. The stability of the reconstructed ligaments were assessed after 1 year postoperatively by physical examination, the deficit of residual extension and flexion was measured in relation to the unaffected contralateral knee and the Lysholm knee scoring scale questionnaire was applied. RESULTS: There was no difference in the assessment of joint stability or of the extension between the groups. In group 1 the passive flexion deficit was less (4.8º +- 5.4º versus 18.2 +- 14.8º, p<0.05) with more patients obtaining a flexion deficit considered normal, or up to 5º (64% versus 18%, p<0.05) and with excellent or good classification in the Lysholm knee scoring scale questionnaire (73% versus 35%, p<0.05). CONCLUSIONS: Compared to the rehabilitation protocol with removable rigid bracing, the use of an articulated external fixator in the treatment of multiligament knee injuries provides equal results for ligament stability, increases the amplitude of the Range of Motion, maintains the extension and reduces the flexion deficit, and provides better functional result

Background: The relevance of conducting this thesis is evident by the fact that bus and coach casualties have been “stubbornly stable” in Europe recent years and a need for investigating if a similar trend could be found in Sweden is therefore obvious. It was also important to add new knowledge to the bus and coach research in Sweden, since many areas were scarcely addressed. Aims: To describe bus and coach occupants’ injuries, crash and injury mechanisms generated in a traffic environment based on data from the medical sector. Additional aims were to investigate the injury reducing effect of a 3-point belt, the effect of cross-winds, and crucial factors in the emergency- and rescue response. Material and methods: Injury data analyses were based on a complete ten-year medical data set from a catchment-area with about 130,000 inhabitants. A number of crash studies with the scope in different crash phases were conducted by applying and elaborating the Haddon matrix as a framework. An additional framework, Protocol for Major Incidents was used in order to investi-gate the emergency- and rescue response to a severe coach crash. Results: Between the first and second five-year period, the incidence of injured in non-crash in-cidents was increased by 24%. In non-crash incidents, 54% were injured; 2/3 while alighting from a bus or coach. The pre-crash factor cross-wind, in addition to vehicle design, vehicle speed and road friction, was investigated in ten crashes. It was confirmed that cross-wind, in relation to vehicle speed and slippery road conditions, needs more attention. The importance of goods load-ing and passengers’ position in the bus, was indicated by the fact that a displacement of the cen-tre of mass rearwards with 10% increased the necessary coefficient of friction with, on average 45%, which in many cases corresponded to dry road conditions. Three Swedish rollover crashes were analysed with regard to the injury outcome, mechanisms and the possible injury reduction for occupants using a safety belt. A considerable increase in safety for occupants belted with 3-point belts was shown through limiting interior contacts, occupant interaction and the possibility of ejection. Crucial post-crash factors in the emergency- and rescue response showed that ordi-nary ways of working and equipment are not always useful and proper equipment for lifting a coach body is essential in the case of a rollover. Finally, the communication between the hospitals is important, and the telephone systems may be overloaded by calls from worried relatives and media. Conclusions: In non-crash events: Non-crash events constitute a majority of all bus and coach casualties with a high proportion of elderly female occupants among the MAIS 2+ injury cases. Boarding and, especially alighting causes many injuries to the lower extremities. In the pre-crash phase: Cross-winds do affect the safety of buses and coaches and requires more at-tention. Seat belt usage among bus and coach occupants has to be increased. In the crash phase: Rollover and ejection are the major causes behind serious and fatal injuries to bus and coach occupants, consequently, retentive glazing, pillars or rails need more attention. An upgrade from 2-point seat belts to 3-point seat belts yields an increase in the estimated injury re-duction from approximately 50% up to 80% for the MAIS 2+ casualties in a rollover crash. In the post-crash phase: In order to be able to lift a coach body proper equipment originated from experience and development is essential in a rescue operation of a crashed bus or coach. Fur-thermore, to improve the emergency response inside crashed coaches proper methods originated from experience need to be developed. Euro NBAP: Based on the results and conclusions generated in this thesis, a European New Bus and Coach Assessment Programme is suggested, which would provide bus and coach occupants with a assessment programme similar to the Euro NCAP.

PURPOSE: Substantial research demonstrates that many nursing homes are not providing adequate quality of care for residents because of inadequate processes of care and insufficient numbers and training of nursing staff. Some residents experience poor-quality outcomes, such as pressure ulcers and unintended weight loss. To address these issues, the long-term care industry has focused on improving quality of care by improving staff education about care processes and reducing nurse turnover rate. The aim of this study was to compare the association between - licensed nurse hours of care and turnover rate to five quality measures—incidence of ADL decline, physical restraints, prevalence of pressure ulcers among residents with risk factors for skin breakdown, and prevalence of unintended weight loss. DESIGN: The study population included 618 freestanding Texas nursing facilities. A cross-sectional multiple regression analysis was conducted using 2007 data to examine the relationship between nurse staffing levels and turnover and resident outcomes with control variables for facility and resident characteristics. RESULTS: The high-risk pressure ulcer variable accounted for 10% of the variation in the regression model. LVN (hprd) was positively associated with an increase in high-risk pressure ulcers. The ADL decline variable accounted for 7.5% of the variation in the regression model, and RN hprd was positively associated with ADL decline. The prevalence of weight loss variable accounted for 3% of the variation in the regression model. RN turnover rate was approaching significance. The physical restraint variable accounted for 2% of the variation in the regression model. LVN contract hprd was significant and positively associated with an increase in physical restraint use although a minimal contribution to the model given the low percentage of LVN contract hprd. The prevalence of low-risk pressure ulcers was not significant. The control variable case mix index was positively associated with ADL decline, high-risk pressure ulcers, and weight loss. CONCLUSIONS: This research will contribute to understanding the relationship of licensed nursing staff to resident outcomes. Additionally, it will contribute to nursing education, research, and policy. While controlling for acuity using case mix index, some negative findings were still noted that requires further research. / text

Nowadays disabled persons are actively integrated into social life. Different compensatory equipment allows them to work and travel independently and one of such means is the wheelchair. Not every disabled person has possibilities to travel by his own car, it is more convenient to use public transport facilities. Transportation safety of the wheelchair users is one of the most important problems facing engineers and transit providers, becouse improperly or totally unsecured wheelchair can lose the stability and tip over during the emergency driving situations. The main object of the scientific research work is complex dynamic system "Man - Wheelchair - Vehicle", whis is under action of environmental factors (road roughness, motion oscillations of vehicle). The main tasks of the work are to form and research nonlinear model of dynamic system considered and to define system's stability limits, providing means for safe travel; to determine main characteristics of the external action and analyze its influence on to dynamic system; to build engineering computation methodology for estimation of the rational parameters to fasten the wheelchair to the vehicle.

Mi tesis utiliza la noción de contrato relacional para explicar pautas aparentemente contraintuitivas de organización vertical. El primer capitulo muestra que, cuando existen externalidades entre empresas, la integración vertical reduce la tentación de sus ejecutivos de bajar el esfuerzo, haciendo sus promisas de cooperar más creibles. El segundo capitulo muestra que, cuando una regulación europea prohibió los territorios exclusivos en la distribución de automóviles, los fabricantes impusieron estándares de servicio y precios maximos, estos últimos para reducir la tentación de los concesionarios de romper pactos informales para no competir. El tercer capitulo muestra que, pese a la asignación simétrica de derechos de decisión en sus contratos de franquicia, los fabricantes de coches dictan estándares a los concesionarios, remunerandolos con descuentos discrecionales. Eso sugiere que los fabricantes son delegados informalmente para tomar decisiones, y usan sus podéres contractuales como recurso extremo contra la tentación de los concesionarios de rechazarlas. / My thesis applies the notion of relational contracts to explain seemingly counterintuitive vertical arrangements. The first chapter shows that, in the presence of spillovers between an upstream and a downstream firm, vertical integration reduces the downstream manager's present gains from shirking, making her promise to cooperate with the upstream firm credible. The second chapter shows that, after a European regulation prohibited exclusive territories, car dealership contracts switched to a mix of service standards and price ceilings, and argues that price ceilings were introduced to reduce the dealers' short-run profits from reneging on an informal "no-compete" agreement. The third chapter shows that, despite the even allocation of decision rights in dealership contracts, car manufacturers dictate performance standards ex post, and reward dealers through discretionary discounts. This suggests manufacturers are informally delegated to set standards, and use formal decision rights as a last resort against the dealers' temptation to overturn their decisions.