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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.
571

Nyutveckling av Huddigs spakkonsoler för modellerna 1060 och 1260

Larsson, Kristoffer January 2008 (has links)
Sammanfattning Författaren Kristoffer Larsson har skrivit rapporten tillsammans med grävlastarstillverkaren Huddig i Hudiksvall. Rapporten beskriver nyutvecklingen av Huddigs spakkonsoler. Bakgrunden till examensarbetet är att Huddig har haft kontinuerlig utveckling av sin interiör och hytt men spakkonsolerna har inte följt med i den utvecklingen. Målet med examensarbetet var att ta fram fyra olika prototyper med hänsyn på utformning, handergonomi, knapplacering, trängstyrningsfunktion, rototilt, materialval och tillverkningsmetod. För att författaren skulle få en bild av vad det fanns för kundsynpunkter och vad andra personen som har en relation till Huddig har för synpunkter gjordes en marknadsundersökning. Därefter följde arbetet med att bryta ned arbetet och produkten i delar med olika metoder. Åtta olika konceptförslag skissades fram och slutligen sållades sex olika delar från koncepten fram. En grupp från Huddig och författaren Kristoffer Larsson tyckte dessa delar var bäst lämpade att gå vidare med. De delar som gick vidare var: − Konisk underdel − Kantig form − Dubbla rader med knappar på vänster konsol − Utåtlutande trängstyrning − Fram/back utåtlutande − Tvåhandsgrepp för trängstyrningen − Placering av stödbensreglage Utifrån dessa kommentarer och synpunkter på de framsållade koncepten skissade författaren fram fyra koncept som valdes att göras prototyper av. Skälet till att prototyper valdes att tillverkas var att det är svårt att känna och testa om ett koncept verkligen fungerar eller inte genom att bara kolla på en skiss. Målet med examensarbetet var att generera fram unika koncept men även att tillverka prototyper av dem, vilket uppnåddes. Utifrån resultat av denna rapport och prototyperna kan Huddig fortsätta att utveckla spakkonsolerna till en genomtänkt och smart lösning. / Abstract The author Kristoffer Larsson wrote this examinations paper for the excavator loader company Huddig AB in Hudiksvall. The subject for this bachelor’s thesis is development of joystick pads at Huddig. The background for the bachelor's thesis is that Huddig have been during the last years developed and redesigning the interior of the cabin. The problem is that the joystick brackets haven’t followed the same development. The goal with this bachelor's thesis is to develop and manufacture four prototypes with consideration on design, ergonomics, bottom positions, control of steering, rototilt, choice of material and manufacturing method. To get a picture of what the drivers want and theirs aspect of the development of the joysticks pads the author did a market research with Huddigs customers. After the market research was done some methods and functions solving methods was used to break down the product to different functions. Eight different concepts were generated and the finial concepts were selected of a group from Huddig and Kristoffer Larsson. They selected the concepts because they taught that they were best suited to manufacture prototypes of. These are the subjects of the concepts: − Conic underpart − Angular design − Double rows with bottoms at left bracket − Tilted steering control − Tilted transport direction shifter − Two hand grip for steering − Placement of hydraulic lifters From these comments and aspects the author drew four sketches to have as guidelines for the prototypes. The reason to make prototypes was that it is hard to anticipate if a concept works in the real life based from a sketch. The goal with this bachelor's thesis was to design and manufacture innovated concepts which have been done. From the result of the bachelor's thesis Huddig can use it to continue to develop the joystick brackets to a successful product.
572

Savitakio ir vakuuminio nuotakyno palyginamoji analizė / Gravity and vacuum sewer system comparison analysis

Navickas, Marius 14 January 2009 (has links)
Magistro studijų baigiamasis darbas, 58 puslapiai, 46 paveikslai, 10 lentelės, 32 literatūros šaltiniai, 9 lietuvių kalba ir 23 už sienio kalba Tyrimo objektas – Vakuuminis ir savitakinis nuotakynas. Darbo tikslas – atlikti vakuuminio ir savitakinio nuotakyno palyginamąją analizę. Uždaviniai: 1. Išanalizuoti sistemų privalumus ir trūkumus; 2. Suprojektuoti savitakinį ir vakuuminį tinklą pasirinktai gyvenvietei; 3. Atlikti suprojektuotų tinklų ekonominė analizė Tyrimo metodai – lietuvių ir už sienio mokslinės literatūros lyginamoji analizė, scheminio vaizdavimo metodas, projektavimas. Išstudijavus Lietuvių ir užsienio literatūrą apie vakuuminį bei savitakinį nuotakyną, apžvelgta dabartinė nuotakynų būklė Lietuvoje, atlikta palyginamoji analizė, nustatyti pagrindiniai sistemų privalumai bei trūkumai, apžvelgtos vakuuminės sistemos pritaikymo sritys. Vilniaus raj. Sakališkių gyvenvietei suprojektuoto vakuuminio bei savitakinio tinklo analizė parodė, kad vakuuminio nuotakyno statybos kaštai yra beveik dvigubai mažesni negu savitakinio. Atlikta analizė parodė, kad vakuuminiai nuotakynai yra perspektyvūs tam tikromis sąlygomis, tačiau Lietuvoje nepagristai nenaudojami. Vakuuminiai nuotakynai yra nepakeičiami projektuojant lygiose, retai apgyvendintose kaimiškose vietovėse. Priimant sprendimą dėl gyvenvietės nuotekų sistemos pasirinkimo, turi būti atliktas bent dviejų skirtingų sistemų variantų palyginimas. / Master degree final work consists of 58 pages, 46 pictures, 10 tables and 32 literatures. Test object – Vacuum and gravity system. Work purpose is to perform vacuum and gravity sewer system’s comparison analysis. Main tasks: 1. Analyze systems advantages and disadvantages; 2. Project gravity and vacuum systems for chosen village; 3. Perform economical analysis for projected systems; Test methods are Lithuanian and foreign scientific literatures comparison analysis, schematic representation method, planning. Overviewed Lithuanian and foreign scientific literature about vacuum and gravity sewer system was overlooked now days sewer situation in Lithuania, completed systems comparison analysis, identified the main systems advantages and disadvantages, overlooked vacuum sewer systems appliances areas, for Sakaliskes village was projected vacuum and gravity systems. Accomplished analysis showed that vacuum sewers are perspective under certain conditions, but in Lithuania interfere unused. Vacuum sewers are unchangeable in flat territories and in rural areas. Before project starts, there should be completed comparison of vacuum, gravity and pressure sever systems.
573

A Soft X-Ray Emission Endstation for the Canadian Light Source

2013 October 1900 (has links)
Based on a previously completed design for a soft X-ray (50-1100 eV) emission spectrometer, an endstation was constructed for the Resonant Elastic and Inelastic X-ray Scattering (REIXS) beamline at the CLS. The optical design employed techniques and software tools developed in-house using ray-tracing and diffraction grating efficiency calculations to analyze and compare existing designs and to propose a new design with superior performance. This design employs Rowland circle geometry to achieve a theoretical resolving power in excess of 2,500 in our range of interest. In addition, a novel optical design for a larger extremely high resolution spectrometer has been completed to provide theoretical resolving powers exceeding 10,000 throughout the higher end of the spectrum. To accommodate this optical design a completely new mechanical design was required, involving significant mechanical, electrical, vacuum and software engineering. Countless custom fabricated parts were required along with numerous o -the-shelf secondary instruments and systems. All told, this entirely student-managed project has cost over $1.5M and taken over 5 years. Construction is finally complete and the endstation is currently being commissioned. Necessary design changes made during the mechanical design process resulting in the selection of a more suitable, but lower resolution, detector. This reduced the theoretical maximum resolving power to 1,800 for the first order gratings and roughly 5,000 for the third order gratings. Commissioning is still underway, but first order resolutions in the range of 1,000 - 2,000 have been recorded as have third order resolutions exceeding 4,000. Publication quality data has been collecting by members of this research group and invited external users have successfully grown and measured samples here. Two of the optical elements required rework and upon their delivery the system commissioning will be completed and peer-reviewed access will begin.
574

Development of an experimental setup for measuring vacuum decay in dual-wall fiber-reinforced composite pipes

Ruhl, Mark Jason Unknown Date
No description available.
575

Development of a basic design tool for multi-effect distillation plant evaporators / H. Bogaards

Bogaards, Hendrik January 2009 (has links)
A need was identified for a set of basic design tools for Multi-Effect Distillation (MED) plant evaporators. This led to an investigation into the different types of evaporators as well as further research on horizontal falling film evaporators as used in the MED process. It also included the theory on these types of evaporators. In order not to duplicate existing design tools, an investigation was also performed on some of the tools that are currently available. The first set of tools that were developed were tools, programmed in EES (Engineering Equation Solver), for the vacuum system and the evaporator. These programs can be used to simulate different parameters (like different mass flows and temperatures). That enables the correct selection of components for the vacuum system and can be used to address sizing issues around the evaporator. It can also be used to plan the layout of the plant. The second of the design tools was developed by designing and building a flow pattern test section. From the flow pattern test section a set of curves for the wetted length under different conditions was obtained which can be used in order to design the sieve tray. This set of curves was found to be accurate for municipal as well as seawater and can be used in the design of the sieve tray of the evaporator. Further development can be done by implementing the figures of the wetted length into a simulation package like, for example, Flownex (a system CFD (Computational Fluid Dynamics) code that enables users to perform detail design, analysis and optimization of a wide range of thermal-fluid systems). The background gained from the study done on the evaporator can also be implemented into such a package. This could solve the problem of different design packages by creating a single design package with all of the above mentioned options included. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2009.
576

Development of a basic design tool for multi-effect distillation plant evaporators / H. Bogaards

Bogaards, Hendrik January 2009 (has links)
A need was identified for a set of basic design tools for Multi-Effect Distillation (MED) plant evaporators. This led to an investigation into the different types of evaporators as well as further research on horizontal falling film evaporators as used in the MED process. It also included the theory on these types of evaporators. In order not to duplicate existing design tools, an investigation was also performed on some of the tools that are currently available. The first set of tools that were developed were tools, programmed in EES (Engineering Equation Solver), for the vacuum system and the evaporator. These programs can be used to simulate different parameters (like different mass flows and temperatures). That enables the correct selection of components for the vacuum system and can be used to address sizing issues around the evaporator. It can also be used to plan the layout of the plant. The second of the design tools was developed by designing and building a flow pattern test section. From the flow pattern test section a set of curves for the wetted length under different conditions was obtained which can be used in order to design the sieve tray. This set of curves was found to be accurate for municipal as well as seawater and can be used in the design of the sieve tray of the evaporator. Further development can be done by implementing the figures of the wetted length into a simulation package like, for example, Flownex (a system CFD (Computational Fluid Dynamics) code that enables users to perform detail design, analysis and optimization of a wide range of thermal-fluid systems). The background gained from the study done on the evaporator can also be implemented into such a package. This could solve the problem of different design packages by creating a single design package with all of the above mentioned options included. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2009.
577

Applications of analyticity to scalar meson phenomenology

Cherry, Stuart Nicholas January 2001 (has links)
The scalar mesons have caused much debate amongst hadronic physicists for many years. Even today the number of scalars is hotly contested, and there is almost no agreement on the composition of any of the experimentally observed states, except perhaps for the K*(_0) (1430). This thesis attempts to shed light on both of these problems via the application of analyticity to two different quantities. Recently a number of authors have proposed the existence of a light, strange, scalar meson known as the k. We perform a direct search of the best available πK scattering data to determine whether or not this resonance exists. This is done by constructing contour integrals from these data and determining the number of poles present inside the contour. We do not need to model either the internal dynamics of the state nor the form of the background scattering. The number of poles found tells us the number of resonances present and their positions allow us to estimate the resonance parameters. We find that there is only one resonance in scalar πK scattering below 1800 MeV and this is identified with the established K*(_0)(1430). We find no evidence for the k. Secondly, applying Cauchy's Theorem to the vacuum polarisation function leads to a relation between experimental and theoretical integrals known as a Finite Energy Sum Rule (FESR). FESRs are used to explore the scalar, isoscalar non-strange current and allow us to determine which of the experimentally observed scalar, isoscalar mesons is most likely to be the uũ + dd state. We find that the lightest scalar, isoscalar uũ dd state is not the fo(980) as suggested by some authors, but is rather the light, broad object known as the fo(400 - 1200). We are also able to estimate the average light quark mass and find m(_q)(l GeV(^2)) = 4.7 ± 0.9 MeV which is consistent with the recent estimates of this quantity from unquenched lattice QCD.
578

Development of an experimental setup for measuring vacuum decay in dual-wall fiber-reinforced composite pipes

Ruhl, Mark Jason 11 1900 (has links)
Thermal management and energy input are required to maintain working fluids, i.e., liquefied natural gas, liquid nitrogen, and multi-phase fluids within their optimal working conditions. Increasing a pipes thermal resistance, e.g., utilizing vacuum insulation, is one method of minimizing energy input. A dual-wall concentric pipe employing a vacuum in the annulus, along with low emissivity surface coatings, is an achievable and economically viable solution. In this study, an experimental setup was designed and utilized to measure the air leakage mass flow rate for single-wall unloaded and mechanically loaded dual-wall fiber reinforced polymeric composite specimens. The mass flow rates were used to develop intrinsic permeability coefficients to quantify leakage, and to determine the maximum serviceable pipe length for a mechanical vacuum pump. In addition, thermal resistance equations were developed to quantify the theoretical heat loss, and an economic study was performed to ascertain the viability for three applications. / Applied Mechanics
579

Procurement of the vacuum waste collection systems : The cases of Hammarby Sjöstad and Stockholm Royal Seaport

Larsson, Veronique January 2013 (has links)
No description available.
580

On the zero-point energy of elliptic-cyliindrical and spheroidal boundaries : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Theoretical Physics at Massey University, New Zealand

Kitson, Adrian Robert January 2009 (has links)
Zero-point energy is the energy of the vacuum. Disturbing the vacuum results in a change in the zero-point energy. In 1948, Casimir considered the change in the zeropoint energy when the vacuumis disturbed by two parallelmetal plates. The plates disturb the vacuum by restricting the quantum fluctuations of the electromagnetic field. Casimir found that the change in the zero-point energy implies that the plates are attracted to each other. With the recent advances made in the experimental verification of this remarkable result, theoretical interest has been rekindled. In addition to the original parallel plate configuration, several other boundaries have been studied. In this thesis, two novel boundaries are considered: elliptic-cylindrical and spheroidal. The results for these boundaries lead to the conjecture that zero-point energy does not change for small deformations of the boundary that preserve volume. Assuming the conjecture, it is shown that zero-point energy plays a stabilizing role in quantum chromodynamics, the leading theory of the strong interaction.

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