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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

Návrh upevňovacího rámu pro zkoušení spalovacího motoru / Mounting Frame Design for IC Engine Testing

Truksa, Jan January 2008 (has links)
In those diploma thesis I engaged in design of mounting frame for mounting mtorcycle four-stroke inline combustion engine to dynamometric testing site. The goal is necessary mobility and versatility of the design. That mean the construction would be useful for other motorcycle engines.
62

Småskaliga vindkraftverk på byggnader i urban miljö : Möjligheter och hinder för ökad implementering / Small-scale wind turbines mounted on buildings in the urban environment : Possibilities and barriers for increased use

Halvarsson, Patrik, Larsson, Emma January 2013 (has links)
Intresset för småskaliga vindkraftverk på byggnader har ökat under de senaste åren. Allt fler människor blir mer energi- och miljömedvetna samt ser fördelarna med att elektriciteten produceras där den konsumeras; i den bebyggda miljön. Det är dock en större utmaning att installera ett vindkraftverk i urban miljö, jämfört med i öppet landskap, då det finns många faktorer som skall beaktas. Stadens komplexa uppbyggnad gör att vindens hastighet och riktning varierar och ger upphov till turbulenta strukturer i den omgivande luften. Många av dagens vindkraftverk kan ej operera effektivt vid turbulens, därför måste dessa vindkraftverken placeras på höga höjder för att nå den laminärt strömmande vinden över staden, vilket ger orealistiska längder på de master som krävs, även om vindkraftverket monteras på en byggnad. För att kunna utnyttja de vindar som uppkommer i urbana miljöer bör vertikalaxlade vindkraftverk med en helixformad geometri på rotorn användas. Dessa har visat sig vara både de effektivaste och de vindkraftverk som utsätter omgivningen för lägst nivå av störningar. Att placera ett vindkraftverk på en byggnad i urban miljö, där många människor vistas, kräver god kunskap om säkert montage samt vilka störningar som vindkraftverket kan generera. Ett vindkraftverk som monteras felaktigt kan bidra till hälso- och säkerhetsrisker, och om dessa risker blir för stora kan vindkraftverket tvingas att tas ur drift. För att vara säker på att vindkraftsanläggningen är tillförlitligt bör vindkraftverket och montaget vara stadardiserat och certifierat, något som i dagsläget saknas i Sverige. I dag finns inga direkta stöd för småskaliga vindkraftverk i Sverige, vilket är en bidragande faktor till att ekonomin kring dessa vindkraftverk är bristfällig. Elcertifikatsystemet som skall ge stöd åt förnyelsebar energi är inte utformat för småskalig elproduktion. Men i takt med att detta användningsområde för vindkraft utvecklas samt att priset för energi förväntas stiga kommer troligtvis byggnadsmonterade vindkraftverk bli en lönsam investering i framtiden. / The interest for small-scale wind turbines mounted on buildings has increased during the last couple of years. More and more people are giving more consideration to energy and environmental questions and are appreciative of the benefits of producing electricity where it is consumed; in the urban environment. However it is a greater challenge to install a wind turbine in the urban environment, compared to an open landscape, because of the many factors that needs to be taken in consideration. The complex structure of the city has an effect on the speed and direction of the wind and causes turbulent structures in the surrounding air. Many of today’s wind turbines cannot operate effectively in turbulence, this is why these turbines need to be placed on high heights to reach the laminar wind flow over the city, which gives unrealistic lengths of the towers that are required, even if the turbine is mounted on a building. To be able to utilize the existing wind in urban environments a vertical axis wind turbine with a helix shaped rotor should be used. These turbines have shown themselves to not only be the most effective but also the turbines that expose the surroundings to the lowest level of disturbances. To place a wind turbine on a building in an urban environment, where a lot of people reside, requires a good knowledge of how to securely mount the turbine but also what kind of disturbances that a turbine can emit. A turbine that is mounted incorrectly can contribute to health and safety hazards, and if these risks become to great the turbine may be forced to be taken out of operation. To be certain that the wind turbine and its components are trustworthy the turbine and mounting should be standardized and certified, a feature that don’t exist today in Sweden.  Currently there is no direct support scheme for small-scale wind turbines in Sweden, which is a contributing factor to the inadequate economics surrounding these wind turbines. The Swedish system with certificates is meant to give support renewable energy but the system is not suited for small-scale production of electricity.  But the more this field of application for wind turbines develops, together with the assumption of rising cost of energy will most likely make building mounted wind turbines a profitable investment in the future.
63

Effektivisering vid montering av KL-element – en pilotstudie av infästningar mellan väggskiva- bjälklagsplatta / More effective installation of CLT-elements – a pilot study on connections of wall-to-floor joints.

Finnhult, Johan, Petersson, Martin January 2020 (has links)
Byggsektorn tenderar idag att välja material med låg miljöpåverkan och bygga energi- och tidseffektiva konstruktioner. Att öka användningen av träprodukter är en del av lösningen. Korslimmat trä (KL-trä) är ett byggmaterial som har blivit mer och mer populärt att använda i byggbranschen. I Sverige har KL-trä använts sedan slutet på 90- talet och användandet ökar för varje år som går. Materialet är relativt nytt och vid monteringen av KL-trä finns det utrymme för förbättringar. Syftet med arbetet är att undersöka och analysera hur dagens infästning av KL-element utförs och hur dessa kan effektiviseras. Målet är att undersöka om det går att korta ner monteringstiden av KL- trästommar. Detta görs genom beräkningar, fältstudie och experiment. I arbetet undersöks möjligheten att reducera skruvning för det vanligast använda vägg till golv anslutningarna och om det finns tid att spara i montaget med hjälp av förborrning. Resultatet av rapporten visar att det finns en potentiell tid motsvarande ca 40 % tidsvinst att spara med förborrade bjälklag från fabrik och andra kvalitétsfördelar som förborrning kan medföra, medan reducering av skruv är möjligt men inte optimerad för dagens mest tillämpade infästningslösningar. / The construction sector today tends to choose material with a low environmental impact and build energy- and time-efficient structures. Increasing the use of wood products is part of the solution. Cross laminated timber (CLT) is a building material that has become more and more popular to use in the construction industry. In Sweden, CLT has been used since the late 90 and its use is increasing every year. The material is relatively new and especially for mounting CLT element, there are still potentials for improvement. The purpose of the work is to investigate and analyze how todays attachment of CLT elements is carried out and how these can be made more efficient. The aim is to investigate whether it is possible to shorten the assembly time of CLT elements. The study was carried out through calculations, study visit and experiments. The work investigates the possibility of reducing screwing for the most commonly used wall to floor joints and showed there is a potential time efficiency of about 40% to be gained with pre-drilled floor element from the factory and other quality benefits that pre-drilling can bring, while the study also showed reducing fasteners under construction phase is possible but not an optimal solution.
64

Проектирование технологического процесса обработки корпусной детали «Корпус адаптера» с элементами исследования средств технологического обеспечения операций в условиях автоматизированного производства : магистерская диссертация / Designing the process of processing the body parts "Adapter housing" with elements of research of technological support tools for operations in automated production conditions

Пупырева, А. С., Pupyreva, A. S. January 2019 (has links)
Работа выполнена на основании данных АО «НПО автоматики». Дипломный проект состоит из трех частей: Технологической, которая включает: описание конструкции детали; определение типа производства; разработку концепции механической обработки детали; выбор вида заготовки и метода её получения; конструирование заготовки и определение общих припусков на обработку; составление планов обработки каждой поверхности в соответствии с этапами обработки; разработку маршрута, включающего назначение базовых поверхностей, выбор станочного оборудования и технологической оснастки; моделирование эскизов на каждую операцию; определение операционных допусков и припусков на обрабатываемые поверхности; определение операционных размеров на обрабатываемые поверхности; выбор режимов обработки; определение норм времени на каждую операцию; оформление рабочей технологической документации. Конструкторской, которая включает: определение потребной силы закрепления (силовой расчёт); выбор и расчёт механизированного привода; точностной анализ приспособления; эскизное конструирование общего вида приспособления; проектирование контрольного приспособления; оформление рабочей конструкторской документации. Научно-исследовательской, которая включает экспериментальное исследование влияния режима резания на качество обрабатываемой поверхности из алюминиевого сплава АМг6 с последующим выводом уравнения регрессии. Графическая часть – 15 листов формата А1; Таблиц – 89; Рисунков – 44; Количество используемых источников – 19. / The work was performed on the basis of the data of JSC "NPO Automation". The graduation project consists of three parts: 1. Technological, which includes: description of the construction details; determining the type of production; development of the concept of machining parts; selection of the type of workpiece and the method of its receipt; design of the workpiece and the definition of total allowances for processing; drawing up plans for the treatment of each surface in accordance with the processing steps; development of the route, including the assignment of base surfaces, the choice of machine equipment and tooling; modeling sketches for each operation; Determination of operating tolerances and allowances for machined surfaces; determination of the operating dimensions of the treated surface; selection of processing modes; determination of time norms for each operation; registration of working technological documentation. Design, which includes: determination of the required strength of fastening (force calculation); selection and calculation of a mechanized drive; accuracy analysis of the device; conceptual design of the general form of the device; design of the control device; design of working design documentation. 3. Research, which includes an experimental study of the influence of the cutting mode on the quality of the processed surface of aluminum alloy AMg6 with the subsequent derivation of the regression equation. - Graphic part - 15 sheets of A1 format; - Tables - 89; Figures -40; The number of sources used - 18.
65

Knock-Knock Door Lock : Unlocking your door with a secret knock sequence / Knack-Knack Öppna Tack

ANDERSSON, FILIP, BERGLING, DAVID January 2020 (has links)
The door lock - a key function in every modern home, as well as a product which is today undergoing drastic change. The digital revolution has not left the door lock untouched, and there is today a wide variety of digital door locks utilizing technologies ranging from touch displays to fingerprint readers. The premises of the project was to try a different approach to the digital door lock and implement it schoolyard-style using a secret knock sequence, set by the user. The secret sequence would consist of two elements, both a rhythmical and a positional pattern. To unlock the door, the user would therefore need to simultaneously knock the correct rhythm and knock at the correct positions. To record and analyze the knock vibrations, piezo electric sensors connected to an Arduino Uno were used. To unlock the door, a small servo motor, two gears and a timing belt were used to turn the lock turning knob . Despite a short time frame and hardships due to the limitations caused by the coronavirus outbreak, a fully functional prototype which fulfilled both reliability and consistency was achieved. It could with good consistency recognize the test sequence, which was the intro rhythm to ”We Will Rock You” knocked in a square pattern. But even with flawless functionality, the conclusion would have been the same. The security of the system may be exceptional from a technical perspective, but it falls flat when the human factor is taken into account. The ability for a potential burglar to simply watch as one executes the secret knock is too much of a security hazard for the system to ever be considered as a competitor to other alternatives. The usage of the system is therefore better suited for applications where the thrill of using the product is more important than the actual security of it. / Dörrlåset - en grundläggande funktion i varje modernt hem, och samtidigt en produkt som idag genomgår drastisk förändring. Som resultat av den digitala revolutionen finns det idag en uppsjö av olika digitala dörrlås som utnyttjar allt från touchskärmar till fingeravtrycksläsare. Syftet med projektet var att testa en annorlunda tappning på det digitala dörrlåset, och förverkliga något många hade drömt om i barndomen - ett dörrlås aktiverat genom ett eget hemligt knackningsmönster. Det hemliga knackningsmönstret skulle då bestå av både ett rytmiskt och ett positionellt mönster. Därmed skulle den som ville öppna dörren behöva knacka både rätt rytm, och på rätt ställen på dörren. För att spela in och analysera vibrationerna från knackningarna användes piezoelektriska sensorer kopplade till en Arduino Uno. Mekanismen som styrde själva upplåsningen bestod av en liten servomotor, två kugghjul och en kuggrem som kopplade samman det hela. Trots en begränsad tidsram och motgångar orsakade av coronaviruset lyckades en fullt fungerande prototyp med hög pålitlighet färdigställas. Den kunde med hög tillförlitlighet känns igen testsekvensen, som var introrytmen till ”We Will Rock You” knackat i mönstret av en kvadrat. Men även med felfri prestanda hade slutsatsen varit densamma. Säkerheten för systemet må vara exeptionell ur ett rent tekniskt perspektiv, men den faller platt när den mänskliga faktorn tas med i beräkningen. Risken att en potentiell inbrottstjuv helt enkelt tittar på när någon knackar det hemliga mönstret är för stor för att systemet någonsin skulle kunna betraktas som en seriös konkurrent till andra digitala dörrlås. Produkten är därmed bäst lämpad för användningsområden där nöjet av att använda den är av högre prioritet än själva säkerheten.
66

Žemės paėmimo visuomenės poreikiams įtakos žvyrkelių rekonstrukcijos kainai VĮ „Telšių regiono keliai“ veiklos zonoje vertinimas / Evaluation of the effect of taking of land for public needs on the price of the gravel roads reconstruction in the state enterprice „Telšių regiono keliai“ activity area

Lašinytė, Asta 13 June 2005 (has links)
The final master‘s work analyzes problems which occur or may occur due to taking the land for public needs when implementing the program of asphalt works on gravel roads in the area of activity of state enterprise „Telšių regiono keliai“. A research of sections of gravel roads intended for reconstruction and included into the program of maintenance and expansion of public highways for 2002–2015 was carried out, in the course of which a road plan was projected following norms of road engineering and the extent of taking the land for public needs was evaluated. Recommendations regarding the expedience of taking the land for road lane when implementing the program of asphalt works on gravel roads in the area of activity of state enterprise „Telšių regiono keliai“ were rendered.
67

Náhrada šroubového spoje dílců světlometu plastovým trnem / Replacement of headlamp parts screw fixation by a plastic nail

Lysa, Bohuslav January 2010 (has links)
The master thesis covers several issues linked to a substitution of headlamp screw fixation by a plastic nail. The thesis includes an analysis of the headlamp technology, including description of the prescribed durability tests. On the basis of the analysis some new designs of plastic nails are proposed, consistent with characteristics of plastic materials. Selected outcomes of the analysis have been tested as prototypes and verified with Finite Elements Method in SimDesigner including 3D modeling capabilities provided by the Catia V5. The feasibility study regarding a casting form of the new design of plastic nails and technical economic valuation for contingent assembly mounting is included in the thesis.
68

The evolution of social behaviour : the effect of mating system and social structure in the European badger Meles meles

Dugdale, Hannah L. January 2007 (has links)
Studies of mating systems and social organisation have been central to understanding of the evolution of social behaviour. The European badger Meles meles is a good species in which to study these processes, as its complex social system provides an opportunity to investigate how both natural and kin selection shape the evolution of mating systems and social structure. In this thesis, I use behavioural and genetic data to describe the mating system and social organisation of a high-density badger population and examine the occurrence of cooperative breeding. I genotyped 915 (85%) badgers trapped in Wytham Woods (1987–2005), 630 of which were cubs, and assigned both parents to 331 cubs with 95% confidence. This revealed a polygynandrous mating system, with up to five mothers and five fathers per social group. Mounting behaviour was also polygynandrous and I show the strongest evidence to date for multiple-paternity litters. I demonstrate, for the first time, that groups consisted of close and distant kin: approximately one third of group members were first-order kin, and overall group members had slightly lower relatedness levels than half-siblings. Within groups, adult and yearling females had higher pairwise relatedness than males, and neighbouring groups contained relatives. These findings result from the high level (42%) of extra-group paternities, 86% of which were assigned to neighbouring males. For the first time I show that females avoided inbreeding by mating with extra-group males; however, incestuous matings did occur. Promiscuous and repeated mountings were observed, which may reduce male–male aggression and infanticide, but may also promote sperm competition, genetic diversity, and / or genetic compatibility. Just under a third of adult males and females were assigned parentage each year and I quantify, for the first time, reproductive skew within badger groups. Correlations between relatedness, group productivity, and reproductive skew were not consistent with the predictions of incomplete-control models; rather, resource availability may play a role. Older and younger badgers displayed reduced annual breeding success, with male success increasing initially with experience. The Restraint, Constraint, and Selection Hypotheses did not explain the age-related breeding pattern in females. Variance in lifetime breeding success (LBS) was greater for males. Males that only bred within or only outside of their groups had half the LBS of males that did both. Females that were assigned maternity probably bred cooperatively and allonursed non-offspring, which has not been demonstrated previously. No benefit was established, however, in terms of litter size, probability of offspring breeding, or offspring lifetime breeding success, with more mothers in a group. In conclusion, badger social groups are fostered through kinship ties. Polygynandry and repeated mounting may have evolved originally to reduce male–male aggression and infanticide by males, through paternity masking. Although plural breeding occurs, group living appears to be costly. Motivation to disperse may be reduced through high-levels of extra-group paternities, which may also reduce inbreeding. Cooperative breeding among mothers may represent a low-cost behaviour with indirect benefits due to high levels of relatedness between female group-members. Badger sociality therefore represents an early stage in the evolution of social behaviour.
69

Městské divadlo v Kuřimi / Theatre House in Kuřim

Petr, Radovan January 2015 (has links)
The theme of the master´s theses is to design a wooden structure of city theater with internal steel construction. The concept of wooden structure is developed in two versions according to standard ČSN EN. The theses solve the static effect of the construction and design of individual parts and materials. Theater has dimensions 49.0 x 25.6 m, max. height of 12.5 meters. The construstion is devise to withstand a weight and applicability. The supporting structure of the roof is solved using by 13 arched plate girders. The second variant is designed as arched truss girders. The gable wall is glassed-in, glass envelopes support by wooden structure with columns and side runners. The work also includes solutions for joins and construction details. The structure was solved in the program RSTAB Dlubal 8. The assessment of the components was done using additional module TIMBER Pro. First Variant of plate girder was checking by manual report. The work includes drawings.
70

Komplex bytových domů, Praha - Jarov, stavebně technologická příprava stavby / The complex of residential buildings, Praha - Jarov, civil technological project

Komenda, Tomáš January 2016 (has links)
The goal of this diploma thesis is to create a building technology project for construction of 4 flat houses within stage 3a. of the building project „Green town of Prague – Jarov, phase II“. The flat houses are in two pairs interconnected by basement, each is a 7 floor high reinforced concrete building with flat roof and is functionally connected to others by a terrace garden system. This document focuses on organisation and preparation of the construction. It includes building site equipment, cost calculation for setting up and servicing of the building site with graphical illustrations for selected construction phases. Additionally a detailed time schedule was created with a proposal for stream construction of the reinforced concrete scelet and lining in the pairs of interconnected buildings. A realization study of the main technological phases was also prepared. The diploma thesis covers in detail construction of reinforced steel scelet and circumferential casing including a layer of contact insulation system. A blueprint of formwork for walls and ceiling is included in the manual for construction of reinforced steel scelet. On these particular actions probationary and control plans were added. The required machinery set with detailed placement was also drafted. An itemized budget for the main building was prepared as well. Attached to this document is a detailed manual on how to use housing units including repairs and revisions plan for next 30 years. Part of this diploma thesis is also a detailed study covering the construction in relation to the surronding living and educational areas.

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