• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 49
  • 12
  • 10
  • 7
  • 4
  • 1
  • 1
  • 1
  • Tagged with
  • 97
  • 26
  • 19
  • 18
  • 16
  • 16
  • 11
  • 11
  • 10
  • 9
  • 9
  • 9
  • 8
  • 8
  • 7
  • 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

Washing and drying reusable sanitary pads

Sundberg, Fanny, Anderhell, Max January 2019 (has links)
Period poverty is a problem mainly found in places characterized by poverty. The lack of means for women and girls to properly handle their menstruation is the essence of the problem. With a lack of both quantity and quality regarding water often being an issue in such places, the hygiene is a constant challenge. Two different kinds of sanitary products are used globally, disposable and reusable. The reusable ones are often being made of cotton or other absorbent materials. Regardless the material, reusable products need cleaning between the times of use, which could be a challenge when water is not always accessible. To have a reusable sanitary pad that efficiently can be cleaned with low amounts of resources is important, especially in impoverished places. Spacerpad is a reusable sanitary pad and a part of a project at the University of Borås. The aim for the project is to reduce period poverty and to educate women and girls in menstrual hygiene management. The pad is made of polyester which does not absorb blood or water, instead the pad merely contains the fluids. This thesis was conducted as a field study in Nairobi, Kenya. The study aimed to simulate a menstruation, in order to analyze the microbial activity in two different reusable sanitary pads, during as well as after menstruation. With the influences from interviews and resources found in Kibera (a slum in Nairobi) a simulation of five days was executed, with nutrient solution instead of menstrual blood. The Spacerpad and a cotton pad were exposed to the same procedures and the effects of washing and drying were studied. The microbial activity was measured with the help of dipslides, a growth medium. The results of this study show that both Spacerpad and the cotton pad could be carriers of heavy growth of bacteria. Increasing microbial activity throughout the simulation as the days went by, ended with a dividing result after a soap wash as the final washing procedure. The pad made of cotton still carried above slight growth, compared to Spacerpad that showed almost no activity after the final cleanse. Even though the microbial activity reached high levels during the simulation, the fact that the Spacerpad can be cleaned with limited resources could be reason enough to consider the Spacerpad as a sufficiently sanitary product in an impoverished place like Kibera. / Mensfattigdom är något som vanligtvis återfinns på platser präglade av fattigdom. Bristen på medel för kvinnor och flickor att kunna hantera sin menstruation är kärnan av problemet. Med en brist i kvantitet och kvalitet på vatten som ett vanligt problem på sådana platser är det en konstant utmaning att upprätthålla sin hygien. Menstruationsskydd delas in i två olika typer, engångs- och återanvändningsbara produkter. De återanvändningsbara produkterna består ofta av bomull eller andra absorberande material. Oavsett material måste produkterna rengöras mellan användningarna, vilket kan vara en utmaning på platser där vatten inte alltid är tillgängligt. Tillgång till en återanvändningsbar binda som kan rengöras med små resurser är viktigt, speciellt på platser som kännetecknas av fattigdom. Spacerpad är en återanvändningsbar binda, framtagen som del av ett projekt vid Högskolan Borås, vars syfte är att reducera mensfattigdom och samtidigt utbilda kvinnor och flickor om menstruation och hygien. Bindan är tillverkad av polyester som inte absorberar blod eller vatten, vilket gör att bindan snarare håller vätskorna på plats. Denna uppsats gjordes som en fältstudie på plats i Nairobi, Kenya och hade som mål att simulera en menstruation. Detta för att se hur den mikrobiella aktiviteten skulle kunna se ut, under och efter en menstruation. Med influenser ur intervjuer och tillgångar från Kibera (ett slumområde i Nairobi) genomfördes simulationen med näringslösning som substitut till mensblod. I simulationen studerades effekten av tvätt och tork på den mikrobiella aktiviteten. Spacerpad och en bomullsbinda genomgick samma processer där aktiviteten mättes med hjälp av dipslides, ett växtmedium. Resultaten från denna studie visar att både Spacerpad och bomullsbindan kan vara bärare av hög tillväxt av bakterier. En ökande bakteriell aktivitet genom testdagarna, slutade med ett tudelat resultat efter en tvåltvätt som sista procedur. Bindan av bomull hade lätt tillväxt, medan Spacerpad knappt visade någon tillväxt alls efter den sista rengöringen. Den mikrobiella aktiviteten hos Spacerpad nådde höga nivåer under simulationen. Trots det så gör förmågan att kunna rengöras med låg åtgång av resurser, att den kan anses vara sanitär nog för att användas på platser präglade av fattigdom, som i Kibera.
62

New Product Development : A Stage-Gate model in a B2B setting for product development with a low level of technological innovation / New Product Development : En Stage-Gate modell i en B2B-miljö för produktutveckling med låg nivå av teknisk innovation

OSBAKK, ALEXANDER, VAKSDAL, HARALD January 2015 (has links)
Företag utvecklar nya produkter för att öka intäkterna och fortsätta vara konkurrenskraftiga. Produktutveckling är ett område det forskats mycket inom och forskningen fokuserar ofta på innovativa produkter. Det ursprungliga problemet för denna uppsats var att göra en undersökning inför utvecklingen av en produkt med låg grad av teknisk innovation. Den tidigare forskningens höga fokus på innovation kombinerat med att uppdragsgivaren inte har några processer för produktutveckling gjorde att uppsatsens omfattning utökades. Denna uppsats presenterar en modell för utveckling av produkter med låg innovation samt en applicering av modellen. Modellen utvecklades genom att studera tidigare litteratur om produktutveckling, främst kring Stage-Gate modeller, och även om kriterier och best-practice inom produktutveckling. Litteraturstudien kombinerades med resultat från intervjuer och resulterade i en modell för utveckling av låginnovativa produkter. Modellen är delad i två delar, den första fokuserar på analys av produktförslaget och den andra fokuserar på att utveckla produkten. Jämfört med tidigare modeller har omfattningen för de olika stegen och gaterna blivit mer fokuserad och tydlig. Den första delen av modellen testades genom att applicera den på det ursprungliga produktförslaget. Testet visade att modellen är passande för den typen av produkter och att de föreslagna generella kriterierna var rimliga. För den specifika produkten visade modellen att produkten var strategiskt passande för företaget och att den är tekniskt genomförbar. De finansiella beräkningarna visade att produkten möjligen inte är tillräckligt attraktiv finansiellt. Några av uppsatsens huvudsakliga slutsatser rör skillnader beroende på hur innovativ produkten är. Processens start skiljer sig signifikant, för innovativa produkter börjar den med en idé och för denna forsknings miljö med ett specifikt förslag. Fokus i finansiella frågor skiljer sig också. Överlag kunde slutsatsen att produktutveckling med en Stage-Gate-metod passar för produkter med låg grad av teknisk innovation dras men det krävs förändringar från tidigare forskning / To increase revenues and continue to stay competitive companies develop new products. Newproduct development is a widely researched field and the focus of the research is often on highly innovative products. The original problem for this thesis was to perform research for the development of a product with a low level of technological innovation. The high focus on innovation in previous research combined with the lack of product development processes in the case company led to a new more extensive scope of this thesis than the original problem. This thesis presents a model for development of products with low level of innovation that has been developed and tested.The model was developed by reviewing previous literature on new product development in general and Stage-Gate models for product development in particular. Literature about criteria and best practices in product development was also studied. The literature review was combined with findings from early interviews and resulted in a development model for low innovative products. The model is divided in two parts, the first focused on analysis of the product suggestion and the second focused on developing the actual product. Compared to previous models, the scope of the stages and gates has been more focused and clear.The first part of the model was tested by applying it to the initial case. The test showed that the model is suitable for a product of that type and that the general criteria proposed was reasonable. For the specific case, the model showed that the product was a strategic fit for the company and that it is technically feasible. The financial calculations showed that the product might not financially attractive enough.Some of the main conclusions of the research are regarding differences depending on how innovative the product is. The starting point differs significantly, with an idea for innovative products and a specific suggestion in the setting of this research. The financial focus also differs. Overall it could be concluded that development with a Stage-Gate approach is suitable for products with low level of technological innovation with some changes from previous literature.
63

A Software Reuse Paradigm for the Next Generation Network (NGN)

Jagot, Bilal Abdull Rahim 17 November 2006 (has links)
MSc thesis - Faculty of Engineering / Service creation in the Next Generation Network (NGN) is focused around software creation and borrows heavily from the Software Engineering community. In the NGN, telecommunication companies demand simple, rapid and economical service creation. The key to this type of service creation is software re-use. Software re-use is a conundrum where limited, dedicated solutions exists. These solutions include amongst others Enterprise JavaBeansTM (EJBs), design patterns and object-oriented programming. The Telecommunications Information Networking Architecture- Conformance And Testing (TINA-CAT) workgroup has done work on a functionality centric concept called RP-facets. This report proposes a redefinition of RP-facets, as Facets, for software re-use across the design and code level. We redefine Facets as functionality centric reusable components. A Facet is independent of the implementation language and the execution platform. Facets allow containment in a structured manner via a user defined Facet Hierarchy. Facets are resource, context and data agnostic. They also introduce a structured way to allow source code to be changed based on design level decisions. Also, possessing the ability to allow the simultaneous use of other reuse solutions and programming paradigms. Abstraction of detail from developers and platform migration can be achieved by using Facets. Facets are composed of a Generic definition and any number of Implementation definitions. The definitions are supported by an underlying informational model called meta-¼. Meta- ¼ is a model at the M3 meta-level that focuses on describing entities. Most of the Facet’s capabilities are enabled by the meta-¼ model. An environment for developing Facets is created, called the Facet Development Environment (FDE). The Facet Developer (FD) role is introduced to develop and maintain Facets. The FD verifies programmes from programmers to be included into the catalogue of Facets via the FDE. The FD interacts with service creation teams to determine which Facets can be used in the service they wish to develop. Facets prove their capability in targeted areas, yet lack in other categories. It is recommended that the underlying informational model should be revised to form a more robust and flexible entity describing model. In addition, a cataloging capability to easily find Facets with particular functionality should be appended to the capabilities of the facet. It is proposed, for future work, that a development environment be created that encompasses a process for using Facets to create services.
64

Guidance and Control for Launch and Vertical Descend of Reusable Launchers using Model Predictive Control and Convex Optimisation

Zaragoza Prous, Guillermo January 2020 (has links)
The increasing market of small and affordable space systems requires fast and reliablelaunch capabilities to cover the current and future demand. This project aims to studyand implement guidance and control schemes for vertical ascent and descent phases ofa reusable launcher. Specifically, the thesis focuses on developing and applying ModelPredictive Control (MPC) and optimisation techniques to several kino-dynamic modelsof rockets. Moreover, the classical MPC method has been modified to include a decreasingfactor for the horizon used, enhancing the performance of the guidance and control.Multiple scenarios of vertical launch, landing and full fligth guidance on Earth and Mars,along with Monte Carlo analysis, were carried out to demonstrate the robustness of thealgorithm against different initial conditions. The results were promising and invite tofurther research.
65

Cross-Contamination Risk of Dental Tray Adhesives: An In Vitro Study

Paczkowski, Isabel, Stingu, Catalina S., Hahnel, Sebastian, Rauch, Angelika, Schierz, Oliver 05 May 2023 (has links)
Background: The aim of this study was to investigate the risk of cross-contamination in dental tray adhesives with reusable brush systems. Methods: Four dental tray adhesives with different disinfectant components were examined for risk as a potential transmission medium for Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Streptococcus oralis, and Candida albicans. Bacterial and fungal strains were mixed with artificial saliva. The contaminated saliva was intentionally added to tray adhesive liquid samples. At baseline and up to 60 min, 100 microliters of each sample were collected and cultivated aerobically on Columbia and Sabouraud agar for 24 or 48 h, respectively. Results: At baseline, contamination with Staphylococcus aureus and Candida albicans could be identified in three out of four adhesives. In the subsequent samples, low counts of up to 20 colony-forming units per milliliter could be observed for Staphylococcus aureus. All other strains did not form colonies at baseline or subsequently. Adhesives with isopropanol or ethyl acetate as disinfectant additives were most effective in preventing contamination, while adhesives with hydrogen chloride or acetone as a disinfectant additive were the least effective. Conclusion: Within 15 min, the tested adhesives appeared to be sufficiently bactericidal and fungicidal against all microorganisms tested.
66

Dynamically reconfigurable parameterized components

Sridhar, Nigamanth 20 May 2004 (has links)
No description available.
67

Creation of a set of tools enabling rapid system engineering loops for small reusable launchers / Skapande av en uppsättning verktyg som möjliggör snabba systemteknikslingor för små återanvändbara bärraketer

Terrien, Louise January 2021 (has links)
The 2010's have seen many changes happening in the launcher world: private players have emerged increasing competition for the traditional launch operators and the development of reusable launcher allowing a decrease in launch cost. The satellite market has also evolved with the appearance of nano-satellites and the development of satellite constellations. ArianeWorks is a joint initiative between CNES and ArianeGroup aiming at accelerating European innovation in the launcher field. Within this framework, Themis, a reusable first stage demonstrator, is currently built and tested. This thesis presents the evaluation of a mini-launcher that would use a derivative of Themis as a first stage. To do so, a set of software tools has been developed and evaluated. These tools make it possible to evaluate various launcher architectures, and to carry out system loops in order to refine the design choices and associated performances. The first results of design and performance from the tools are also presented. / Under 2010-talet har många förändringar skett i bärraketvärlden: privata aktörer har dykt upp och ökad konkurrensen för de traditionella operatörerna. Utvecklingen av återanvändbara bärraketer möjliggör en minskning av uppskjutningskostnaden. Satellitmarknaden har också utvecklats med uppkomsten av nanosatelliter och utvecklingen av satellitkonstellationer. ArianeWorks är ett gemensamt initiativ mellan CNES och ArianeGroup som syftar till att påskynda europeisk innovation inom bärraketområdet. Inom detta ramverk byggs och testas för närvarande Themis, en återanvändbar demonstrator för ett första raketsteg. Den här uppsatsen presenterar utvärderingen av en ministartare som använder en del av Themis. Inom detta arbetet har en uppsättning mjukvaruverktyg utvecklats och utvärderats. Dessa verktyg gör det möjligt att utvärdera olika bärraketutformningar och utföra systemloopar för att förfina utformningsval och tillhörande prestanda. De första resultaten av utformningen och prestandan presenteras.
68

Design and Development of a Cold-Flow Test-Bench for Study of Advanced Nozzles in Subsonic Counter-Flows

Scarlatella, Giuseppe, Sieder-Katzmann, Jan, Roßberg, Florian, Weber, Felix, Mancera, Carlos T., Bianchi, Daniele, Tajmar, Martin, Bach, Christian 04 June 2024 (has links)
As advanced nozzles may offer alternative solutions to conventional nozzles for the future class of reusable launch vehicles, a critical aspect is to tailor these novel technologies to current recovery strategies, more specifically to vertical landing sustained by retro-propulsion. Researchers at Technische Universität Dresden have developed a dedicated test-bench for the vacuum wind tunnel facility, where Advanced Nozzle Concepts (ANCs), such as aerospike and dual-bell nozzles, are tested in cold-gas configuration while invested by subsonic counter-flows. The main objective of the test campaign is to evaluate the performance and altitude–compensation characteristics of such ANCs by simulating a vertical landing manoeuvre through the variation of ambient pressure experienced during the landing burn. A detailed description of design and development of the test-bench, together with preliminary results from the commissioning activities, are here offered to the reader. The force measurements, together with pressure and temperature data, contribute to evaluate thrust levels and coefficients, as well as the monitoring of the interaction between the nozzle cold-flow and the opposing free-stream. A background-oriented schlieren system allows to visualise the external flow-field. In conclusion, an outline of the upcoming test campaign and a description of the expected results is offered.
69

Health Monitoring of Reuseable Rockets: Basics for Sensor Selection

Vennitti, Andrea, Schmiel, Tino, Bach, Christian, Tajmar, Martin 19 April 2024 (has links)
With regard to the space field, the number of the sensors has grown for a middle-sized spacecraft from more than 500 at the beginning of the twenty-first century [1] to several thousands for nowadays applications. Meanwhile, Reusable Launch Vehicles (RLVs) moved their steps from demonstrators to commercial working systems. As a result, Health Monitoring (HM) is conquered its own space in the field and sensors are the primary elements required for implementing a monitoring unit. The innovative concept of reusable rockets requires, from the point of view of HM implementation, not only the evaluation of the vehicle health status but also the prediction of the reusability of the individual subsystems w.r.t. the next launch cycle. Therefore, the goal of this work is divided in two parts. The former is to identify the most critical points for the development of reusable rockets, focusing on theoretical working conditions and analysis or failures. The latter is to discuss the sensing units useful for addressing the defined points, describing the possible innovative approaches for sensing the system conditions. Among them, piezoelectric units, fiber optics, imaging units, and conductive layers can be identified for enhancing the comprehension of the system working conditions.
70

New composite flooring system for the circular economy

Lam, Dennis, Yang, Jie, Wang, Yong, Dai, Xianghe, Sheehan, Therese, Zhou, Kan 15 September 2021 (has links)
No / Circular economy is an economic system aimed at minimizing wastes and making the most of the current resources. This regenerative approach contrasts with the traditional linear economy, which has been adopted by the construction industry. Developing new construction technologies for sustainable built environment is a top priority for the construction industry throughout the world. Much of the environmental impact from the construction industry is associated with the consumption of resources and generation of waste. The construction industry in Europe consumes over 70,000 million tonnes of materials each year and generates over 250 million tonnes of waste. Composite flooring formed by connecting the concrete slabs to the supporting steel beams has been widely used for many years and is well established as one of the most efficient floor systems in multi storey steel frame building structures. However, shear connectors are welded through the steel decking to the steel beams and cast into the concrete; this made deconstruction and reuse of these components almost impossible. A new composite flooring system which allows for the reuse of the steel beams and composite floor slabs is developed and tested to assess its potential and suitability for reuse. This paper presents the results of a series of full scale beam tests and demonstrates the reusability of this new form of composite flooring systems. Simplified hand calculations are also provided and compared against beam tests / EPSRC, Structural Metal Deck Ltd.

Page generated in 0.0251 seconds