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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.
951

Driving organisational culture change for sustainability. Employee engagement as means to fully embed sustainability into organisations

Vargas, Anamaria, Negro, Pietro Antonio January 2019 (has links)
When integrating sustainability, companies are often overlooking the changes needed in their organisational culture. This hinders organisations’ core business to efficiently embed sustainability and dooms corporate sustainability initiatives to be superficial. A possible solution is for organisations to develop a sustainability- oriented organisational culture that engages employees with the sustainability change and that develops a leadership supportive of the engagement of their employees. As a result, this thesis aims at exploring how organisations can change their organisational culture in order to fully integrate sustainability by engaging employees and managers. Specifically, it studies how employee engagement can contribute to transforming organizational cultures to fully embed sustainability. Additionally, this paper analyses how managers can support employee engagement with sustainability. The thesis conducts a literature review to set the theoretical foundations; it further resorts to semi-structured interviews and document analysis conducted in a Swedish public company, which has begun to integrate sustainability into its culture. The study finds that organisations’ cultures are being changed at the artifact levels and, partially, at the values and beliefs level of their cultures. Additionally, the thesis establishes that organisations are failing to create the conditions for employee engagement. It finally shows that leadership in companies is not efficiently supporting the engagement of employees to integrate sustainability into their culture.
952

Search for the production of four top quarks in proton-proton collisions at $\sqrt{s}=13$ TeV in the single lepton and opposite-sign dilepton channels with the ATLAS detector at the Large Hadron Collider

Sabatini, Paolo 10 February 2020 (has links)
No description available.
953

Synthesis of polymers and oligomers containing fluorinated side groups for the construction of hydrophobic surfaces

Zhuang, Rong-Chuan 06 June 2005 (has links)
Oligomers and polymers based on functionalized Rf-amides were successfully synthesized for the fabrication of hydrophobic surfaces with either linear or network structure. Firstly, new functionalized Rf-amides (RfCONH-, Rf is a perfluoroalkyl segment) were developed in most cases by a one step reaction and a simple work-up procedure. The reaction behaviors of synthesized Rf-amides in polyreactions were well understood. New fluorinated oligoester polyols, blocked IPDI's, and end-hydroxyl terminated oligo(urea urethane)s have been synthesized, the detail structures and properties are well understood. These materials could be suitable components of powder coatings. On the other hand, the end-hydroxyl terminated oligo(urea urethane)s could be used as reactive additives in high solid content and water-borne coatings. Hydrophobic smooth surfaces based on linear polymers, poly(urea urethane)s and alternating MI copolymers, containing fluorinated side groups were successfully constructed. The attachment of fluorinated side groups into polymers can dramatically alter the surfaces of corresponding polymers from more hydrophilic to hydrophobic due to the enrichment of fluorinated side groups on the top of the surface. The backbone configuration, the polarity of backbones, and the thermal treatment on surfaces can influence the surface properties of corresponding materials. Finally, hydrophobic surfaces of cross-linked polyurethanes as model top coatings were constructed under melt condition at high temperature (180 and 190 oC) using the combination of fluorinated oligouretdiones and non-fluorinated oligoester polyols. It was found that the hydrophobicity of resulting cured films is a matter of the competition between the formation of cross-linking network and the segregation of fluoromoieties on the top of the surface.
954

Factors Underlying Invasive Grass Fire Regimes in the Mojave Desert and its Consequences on Plant and Animal Communities

Horn, Kevin J. 08 July 2013 (has links)
Climate change and exotic plant invasions are significant anthropogenic threats to desert community structure and resilience . In the Mojave Desert, the invasive grass red brome (Bromusrubens L) is increasing fire frequency and extent in response to climatic factors. The resilience of this ecosystem will be affected by how plant and animal communities respond to fire. To better understand these dynamics, we studied the environmental factors underlying changes in invasive grass fire regimes in the Mojave Desert and its structural and functional effects on plant and animal communities. Following fire, reestablishment of native vegetation can be preempted by repeated burning associated with the abundant exotic grass red brome. Red brome density is correlated with various climate and landscape variables, but to establish causality, we experimentally assessed germination and growth of red brome. Red brome responded positively to fall precipitation, finer-textured soils, fertile-islands soils, and soils from burned landscapes. Red brome germination is maximized in wet fall periods when adequate water and optimal temperatures overlap . To evaluate landscape responses of pre- and post-fire plant communities and the potential for repeated burning we analyzed vegetation greenness (NDVI) data from 1985-2011 in response to temperature and precipitation. Landscape analysis indicated that the dominance of exotic grasses increases on post-fire landscapes. Following wet fall and winter seasons, high red brome productivity increases fire potential. Without mitigation, the establishment of an invasive-plant-driven fire regime is likely and may drive state transitions from arid shrublands to arid annual grasslands. Potential revegetation of post-fire landscapes will depend at least in part upon the physiological response of surviving vegetation to post-fire landscapes. Plant physiological responses to post-fire landscapes were generally neutral or positive, suggesting that revegetation of post-fire landscapes is not precluded by resource loss associated with fire and may even be enhanced by post-fire conditions. This will likely translate to increased reproductive potential of surviving plants. Alterations to small mammal populations will likely play a role in the reestablishment of vegetation (both native and exotics) as small mammals have strong top-down effects in arid ecosystems. Diversity and species richness responded negatively to burned landscapes as Merriam's kangaroo rat (Dipodomys merriami) increased in abundance while other species practically disappeared from burned landscapes. Merriam's kangaroo rat affects propagule sources through direct consumption, and seed dispersal. Increases in abundance and dominance of Merriam's kangaroo rat will likely alter plant recruitment.
955

Experimentální studium modifikátorů tření v kolejové dopravě / Experimental study of friction modifiers in rail transportation

Knápek, Jiří January 2017 (has links)
The adhesion in the wheel-rail contact can be effectively controlled by using the friction modifier. Adhesion control can reduce excessive wear of the contact bodies or noise. The essence of this diploma thesis is to determine the optimal amount of friction modifier in wheel-rail contact depending on the climatic and operating conditions. For experimental study of the behavior of the friction modifier, the twin-disc device is used. Twin-disc simulates and controls the most important operating parameters such as speed, slip, attack angle or contact pressure. On the basis of these findings, the off-board top-of-rail lubricator system was designed. This system controls the amount of friction modifier according to current climatic and operating conditions.
956

Friction Modification within Wheel-Rail Contact / Friction Modification within Wheel-Rail Contact

Galas, Radovan January 2018 (has links)
Předložená disertační práce se zabývá experimentálním studiem modifikátorů tření a maziv pro temeno kolejnice, které jsou aplikovány do kontaktu kola a kolejnice za účelem optimalizace adheze a redukce hluku. Hlavním cílem práce bylo objasnit vliv aplikovaného množství a složení těchto látek na adhezi v kontaktu. Hlavní pozornost byla věnována zejména potencionálním hrozbám souvisejících s kriticky nízkou adhezí, která může nastat po aplikaci těchto látek. Experimentální studium probíhalo v laboratorních i reálných podmínkách, konkrétně v tramvajovém provozu. V případě laboratorních experimentů byl využit komerční tribometr a dvoudiskové zařízení umožňující simulovat průjezd vozidla traťovým obloukem. Kromě samotné adheze bylo při experimentech sledováno také opotřebení a míra hluku. Výsledky ukázaly, že maziva pro temeno kolejnice jsou schopna poskytovat požadované třecí vlastnosti, nicméně jejich chování je silně závislé na aplikovaném množství. V případě předávkování kontaktu dochází ke kriticky nízkým hodnotám adheze, které vedou k výraznému prodloužení brzdné dráhy. V případě modifikátorů tření bylo ukázáno, že chování těchto látek je výrazně ovlivněno odpařováním základního média. Výsledky také ukázaly, že nadměrné množství částic pro modifikaci tření může způsobit kriticky nízké hodnoty adheze. U obou výše zmíněných typů produktů byl prokázán pozitivní vliv na míru opotřebení a míru poškození povrchu, zatímco významná redukce hluku byla dosažena pouze v případech, kdy došlo ke značnému poklesu adheze. V závěru této práce jsou uvedena doporučení pro další výzkumné aktivity v této oblasti.
957

Konstrukční návrh otočného stolu s nosností 65 000 kilogramů / Design of rotary table with maximal load capacity 65 000 kg

Bezděk, Petr January 2021 (has links)
The diploma thesis deals with the design of a rotary table for machining large non-rotary workpieces up to a maximum weight of 65 000 kg. The aim of the work is to analyze and evaluate the current state of knowledge in the field of rotary tables, to create a table design according to the assignment and its 3D model with part of the drawing documentation. The theoretical part of the work searches for solutions used in the construction of rotary tables in the category of table according to the assignment. The information obtained is further used in the design of rotary table solution variants. By evaluating the weight of the required properties and their degree of fulfillment, a variant of the design solution of the table is selected, which is then designed. The individual design steps are described and explained in the text part of the work accompanied by pictures and calculations. The result of the process is a structural design of the mechanical part of the rotary table with a 3D model and partially processed drawing documentation. The contribution of the work is the summarization of relevant information for the design of rotary tables, the processed procedure of solving the design of the table and the modeled design of the rotary table. These outputs can be further treated as documentation for the production of the designed table, the development of the rotary table design to deeper details or technical development in this area.
958

Optimización de procesos constructivos de cimentación aplicando metodología top down en edificaciones de oficinas en la ciudad de Lima

Napa Ercilla, Gumer Mayco 25 October 2019 (has links)
En el presente trabajo se realizó una evaluación de construcción de una edificación de oficinas en Lima mediante dos procesos constructivos, el tradicional con estabilización de muros anclados y cimentación de zapatas versus el Top Down con pantallas y pilotes. La misma que determinará cual es el proceso que brinda mejores resultados, evaluando las diferencias como propuesta técnica y económica. Para esta evaluación se desarrollan seis capítulos. En el capítulo número uno, se describe el plan de trabajo a seguir para llegar a los objetivos planteados. El segundo capítulo, abarca el marco teórico, en el cual se describen conceptos, procedimientos, metodología, beneficios, restricciones y aplicaciones de cada proceso en evaluación. En el tercer capítulo, se realiza un análisis descriptivo de las variables técnicas y económicas del proceso constructivo tradicional con muro anclados y cimentación tradicional versus el top down. En el cuarto capítulo, se presenta la propuesta de optimización aplicando la metodología top down para el proyecto en evaluación, en este capítulo se describe criterios de selección de proyecto, metodología, plazo y costos asociados. Además, se analiza el costo de alquiler del metro cuadrado de oficina en la zona del proyecto, para posteriormente considerar el retorno de inversión. En el quinto capítulo, se realiza un análisis descriptivo y comparativo entre las principales variables técnicas y económicas de los resultados de cada evaluación. Con ello se determina los beneficios y restricciones de cada proceso constructivo. Finalmente, en el capítulo seis se presenta conclusiones y recomendaciones según los objetivos planteados. / In the present work a construction an office building in Lima has been evaluated through two construction processes, starting with the traditional one that consist of the stabilization of anchored walls versus the Top Down constructive process with foundation piles, the same that will determine which system provides better results, as well as the evaluation of the incidences related to cost and time. For this evaluation six chapters have been developed. In the first chapter, we describe the work plan to follow in order to reach the objectives proposed. The second chapter covers the theoretical framework which consist of describing main concepts, advantages, procedures and applications of each process under evaluation. In the third chapter, a descriptive analysis of the technical and economic variables is developed according to the building process with traditional foundation and anchored walls versus the top-down. In the fourth chapter, the project under evaluation is presented based on the top-down methodology, taking into account the selection criteria, methodology, the time limit and the cost associated. In addition, the office renting cost is analyzed according the square meter of the project for a later consideration of the investment return. On the other hand, in the fifth chapter, a descriptive analysis of the results of each process is carried out and comparative result tables of the principal technical and economic variables, thereby determining the best construction alternative. Finally, in chapter six, conclusions and recommendations are presented according to the objectives set. / Tesis
959

Měření parametrů přijímače pro digitální televizi DVB-T (set-top boxu) / Measurements of the DVB-T Digital Television Receiver Parameters

Komenda, Jan January 2009 (has links)
The diploma thesis is focused on the measurement of selected parameters of the digital TV receiver DVB T, set top box. In the introductory part the work briefly deals with the theory of compression and transmission of the digital TV signal. Main part of the thesis contains detail information about individual circuits of the selected set top box Humax F3-FOX T and the results of measurements of individual parameters obtained from the available measuring devices. The final part of the thesis deals with the design changes necessary for creation of the external output for the signals and also with the methodology of the measurement.
960

Měření přijímače pro pozemní digitální televizi DVB-T / Measurements of the DVB-T Digital Television Receiver

Kobza, Jaromír January 2010 (has links)
This thesis is focused on a receiver for digital television broadcasting set-top box, mainly on its features, parameters and measurement. The important point of this work is the possibility to analyze and visualize the parallel transport stream in the same time and the solution of this problem. The principle of tuner and its measuring is deeply discussed. The text is supported with oscilloscope screenshots in particular parts of decoding stream. The set-top box is modified for laboratory measurement purpose and the transport stream output is added. An example laboratory exercise was created as a part of this work.

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