To see the other types of publications on this topic, follow the link: TEE.

Dissertations / Theses on the topic 'TEE'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'TEE.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Schuh, Christian. "Wichtige Aromastoffe in schwarzem und grünem Tee (Camellia sinensis)." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973910054.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Portatius, Amélie$cvon [Verfasser]. "Die Wirkung von grünem Tee, schwarzem Tee sowie schwarzem Tee mit Milch auf die vaskuläre Endothelfunktion bei postmenopausalen Frauen / Amélie von Portatius." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2009. http://d-nb.info/1023750112/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Powers, Kristin L. "a house on Tee street." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/33230.

Full text
Abstract:
Combining both roof and shelter into one creates several design opportunities for a small house for college students living in Blacksburg, VA. The roof will serve many purposes, including structure, rain water collection, and inhabitable space. The house has two volumes overlapped into a large cubic volume to create different spaces which can be reached through overlapping stairs leading to the different levels of the house.
Master of Architecture
APA, Harvard, Vancouver, ISO, and other styles
4

Klimusch, Anna. "Metabolismus des Insektizids Deltamethrin in der Teepflanze Abbau, Bildung konjugierter und gebundener Rückstände sowie Analyse der Aufgüsse von unterschiedlichen Teearten." Berlin Logos-Verl, 2007. http://deposit.d-nb.de/cgi-bin/dokserv?id=3033635&prov=M&dok_var=1&dok_ext=htm.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Monclova, Luis A. "Numerical simulation of a pipeline tee mixer." Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/11023.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Read, Paul John Charles Lewis. "Fatigue characterisation of FRP structural tee joints." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242730.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Shohel, Muhammad Shah Newaz. "Panting Fatigue of Welded Steel Tee Details." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1428328220.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Charron, Yves. "Two-phase flow in a vertical tee junction." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356962.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Dhar, Siddharth. "Optimizing TEE Protection by Automatically Augmenting Requirements Specifications." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/98730.

Full text
Abstract:
An increasing number of software systems must safeguard their confidential data and code, referred to as critical program information (CPI). Such safeguarding is commonly accomplished by isolating CPI in a trusted execution environment (TEE), with the isolated CPI becoming a trusted computing base (TCB). TEE protection incurs heavy performance costs, as TEE-based functionality is expensive to both invoke and execute. Despite these costs, projects that use TEEs tend to have unnecessarily large TCBs. As based on our analysis, developers often put code and data into TEE for convenience rather than protection reasons, thus not only compromising performance but also reducing the effectiveness of TEE protection. In order for TEEs to provide maximum benefits for protecting CPI, their usage must be systematically incorporated into the entire software engineering process, starting from Requirements Engineering. To address this problem, we present a novel approach that incorporates TEEs in the Requirements Engineering phase by using natural language processing (NLP) to classify those software requirements that are security critical and should be isolated in TEE. Our approach takes as input a requirements specification and outputs a list of annotated software requirements. The annotations recommend to the developer which corresponding features comprise CPI that should be protected in a TEE. Our evaluation results indicate that our approach identifies CPI with a high degree of accuracy to incorporate safeguarding CPI into Requirements Engineering.
Master of Science
An increasing number of software systems must safeguard their confidential data like passwords, payment information, personal details, etc. This confidential information is commonly protected using a Trusted Execution Environment (TEE), an isolated environment provided by either the existing processor or separate hardware that interacts with the operating system to secure sensitive data and code. Unfortunately, TEE protection incurs heavy performance costs, with TEEs being slower than modern processors and frequent communication between the system and the TEE incurring heavy performance overhead. We discovered that developers often put code and data into TEE for convenience rather than protection purposes, thus not only hurting performance but also reducing the effectiveness of TEE protection. By thoroughly examining a project's features in the Requirements Engineering phase, which defines the project's functionalities, developers would be able to understand which features handle confidential data. To that end, we present a novel approach that incorporates TEEs in the Requirements Engineering phase by means of Natural Language Processing (NLP) tools to categorize the project requirements that may warrant TEE protection. Our approach takes as input a project's requirements and outputs a list of categorized requirements defining which requirements are likely to make use of confidential information. Our evaluation results indicate that our approach performs this categorization with a high degree of accuracy to incorporate safeguarding the confidentiality related features in the Requirements Engineering phase.
APA, Harvard, Vancouver, ISO, and other styles
10

Ahlcrona, Sara. "Tee Tree Oil - Ett effektivt behandlingspreparat i tandvården?" Thesis, Malmö högskola, Odontologiska fakulteten (OD), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-19927.

Full text
Abstract:
Tea Tree Oil eller TTO som det förkortas, är en olja som utvinns ur en australiensisk buske vid det latinska namnet Melaleuca alternifolia. Oljan har sedan många år använts som antiinflammatoriskt och bakteriedödande ämne. Denna litteraturstudie gjordes på 13 artiklar som svarade på tre sökningar i databasen PubMed. Artiklarna påvisar att TTO har en viss antibakteriell förmåga och kan fungera som antimykotiskt medel, men fler in vivo studer behövs för att säkerställa TTO:s effekt på olika parodontala åkommor.
APA, Harvard, Vancouver, ISO, and other styles
11

Förg, Alexander. "Hochdruck-Anreicherungen polarer Pflanzenwirkstoffe ohne und mit integrierter adsorptiver Extraktreinigung." [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=963951106.

Full text
APA, Harvard, Vancouver, ISO, and other styles
12

Sert, Cumhur. "Entwicklung einer schonenden Trocknungstechnologie zur Pulverisierung wässriger Naturstoffextrakte." Aachen Shaker, 2008. http://d-nb.info/99182007X/04.

Full text
APA, Harvard, Vancouver, ISO, and other styles
13

Fulford, Andrew Richard Wentworth Stuart M. "Conductor and dielectric property extraction using microstrip tee resonators." Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Summer/master's/FULFORD_ANDREW_7.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
14

Lim, Steven. "Recommending TEE-based Functions Using a Deep Learning Model." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/104999.

Full text
Abstract:
Trusted execution environments (TEEs) are an emerging technology that provides a protected hardware environment for processing and storing sensitive information. By using TEEs, developers can bolster the security of software systems. However, incorporating TEE into existing software systems can be a costly and labor-intensive endeavor. Software maintenance—changing software after its initial release—is known to contribute the majority of the cost in the software development lifecycle. The first step of making use of a TEE requires that developers accurately identify which pieces of code would benefit from being protected in a TEE. For large code bases, this identification process can be quite tedious and time-consuming. To help reduce the software maintenance costs associated with introducing a TEE into existing software, this thesis introduces ML-TEE, a recommendation tool that uses a deep learning model to classify whether an input function handles sensitive information or sensitive code. By applying ML-TEE, developers can reduce the burden of manual code inspection and analysis. ML-TEE's model was trained and tested on functions from GitHub repositories that use Intel SGX and on an imbalanced dataset. The accuracy of the final model used in the recommendation system has an accuracy of 98.86% and an F1 score of 80.00%. In addition, we conducted a pilot study, in which participants were asked to identify functions that needed to be placed inside a TEE in a third-party project. The study found that on average, participants who had access to the recommendation system's output had a 4% higher accuracy and completed the task 21% faster.
Master of Science
Improving the security of software systems has become critically important. A trusted execution environment (TEE) is an emerging technology that can help secure software that uses or stores confidential information. To make use of this technology, developers need to identify which pieces of code handle confidential information and should thus be placed in a TEE. However, this process is costly and laborious because it requires the developers to understand the code well enough to make the appropriate changes in order to incorporate a TEE. This process can become challenging for large software that contains millions of lines of code. To help reduce the cost incurred in the process of identifying which pieces of code should be placed within a TEE, this thesis presents ML-TEE, a recommendation system that uses a deep learning model to help reduce the number of lines of code a developer needs to inspect. Our results show that the recommendation system achieves high accuracy as well as a good balance between precision and recall. In addition, we conducted a pilot study and found that participants from the intervention group who used the output from the recommendation system managed to achieve a higher average accuracy and perform the assigned task faster than the participants in the control group.
APA, Harvard, Vancouver, ISO, and other styles
15

Selbach, Michael. "Darstellung des Raums Circumflexus mittels TEE zur minimalinvasiven Diagnostik des Versorgungstyps und zur prophylaktischen Kontrolle eines iatrogenen Verschlusses bei Mitralklappenrekonstruktion." Doctoral thesis, Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-175163.

Full text
Abstract:
Im Rahmen dieser Dissertation wurde in einer prospektiven klinischen Studie bei 110 kardiochirurgischen Patienten, welche sich einer Mitralklappenrekonstruktion [MKR] unterzogen, untersucht, ob mittels transösophagealer Echokardiographie [TEE] die Durchblutung der Koronarien zu Beginn, während und nach der Operation dargestellt werden kann und ob die anatomischen Gegebenheiten gut abzugrenzen sind. Dabei wurden der Ramus Circumflexus [RCX] und der Sinus Coronarius [SC] im gesamten Verlauf verfolgt, der Diameter proximal (nach Abgang der Aorta), im Verlauf (bei Überkreuzung der arteriellen und venösen Gefäße) und distal bestimmt und der Blutfluss mittels Dopplersonographie dargestellt. Ein weiterer Punkt war die Untersuchung, ob anhand des Kalibers der Gefäße verlässliche Rückschlüsse auf den Versorgungstyp geschlossen werden können, was sonst nur mittels Koronarangiographie [CA] unter Einsatz von Kontrastmittel invasiv darzustellen war. Zuletzt wurde beim sich noch in Narkose befindlichen Patienten untersucht, ob evtl. erst postoperativ durch iatrogenen Verschluss aufgetretene Wandbewegungsstörungen mittels TEE minimalinvasiv diagnostiziert werden können, sodass ggf. eine sofortige Intervention erfolgen konnte. In der Phase der Datenerhebung kam es bei drei Patienten zu Komplikationen im Sinne einer Obstruktion bzw. Stenose der RCX, wobei die Befunde der TEE-Untersuchungen zusammenmit den klinischen Symptomen in einer anschließenden Koronarangiographie bestätigt wurden. Die Ergebnisse dieser Studie wurden im Jahr 2010 in „The annals of thoracic surgery“ unter dem Titel „Echocardiographic Identification of Iatrogenic Injury of the Circumflex Artery During Minimally Invasive Mitral Valve Repair“ veröffentlicht (1).
APA, Harvard, Vancouver, ISO, and other styles
16

Stoppe, Sebastian. "„Tee, Earl Grey, heiß“: Star Trek und die technisierte Gesellschaft." LIT, 2008. https://ul.qucosa.de/id/qucosa%3A20899.

Full text
Abstract:
Der Schöpfer der Science-Fiction-Serie Babylon 5 J. Michael Straczynski musste sich in einem Interview die Frage gefallen lassen, warum in seiner Serie die alltägliche Kommunikation noch über Handgeräte abgewickelt würde. Schließlich sei es doch heute allgemein akzeptiert, dass so genannte Kommunikatoren, die an die Brust geheftet werden, die vorherrschende Technologie der Zukunft sein werden. Diese Art von Technik, Kommunikatoren, tauchten zum ersten Mal 1987 in der Fernsehserie Star Trek: The Next Generation auf. In der Tat lösten sie in der Star Trek-Zeitlinie jene Handgeräte ab, die 1966 erstmals von Captain James T. Kirk und seiner Crew in Star Trek: The Original Series verwendet wurden und die eine frappierende Ähnlichkeit mit den kleinen Mobiltelefonen der Gegenwart besitzen. Diese kleine Anekdote macht deutlich, wie sehr Star Trek im gesellschaftlichen Diskurs mit alltäglich benutzter Technik assoziiert wird und welche mächtige Position diese Science-Fiction-Serie in unserer Populärkultur einnimmt, dass sich sogar andere Science-Fiction-Serien, die in völlig anderen zukünftigen Parallelwelten spielen, nach ihr richten sollen. Ist Star Trek tatsächlich so von Technik dominiert, dass sich andere Serien danach richten sollen? Wie wird die Technisierung der Gesellschaft in Star Trek thematisiert? Welche Konsequenzen ergeben sich daraus? Und auf welche Weise reflektiert das Star Trek-Universum die technische Fortentwicklung der Gegenwart?
APA, Harvard, Vancouver, ISO, and other styles
17

Schmid, Anne. "Investigation of Double Tee Seismic Moment Connections with HSS Columns." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1511795426731486.

Full text
APA, Harvard, Vancouver, ISO, and other styles
18

Solsjö, Oskar. "Secure key management in a trusted domain on mobile devices." Thesis, Linköpings universitet, Databas och informationsteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-118501.

Full text
Abstract:
As mobile devices manage more and more sensitive information they have become a more targeted platform to exploit. To maintain system integrity while providing a highly responsive product, platform developers have developed hardware as well as software solutions to improve security. Until recently however, it was only possible to devise hardware solutions to achieve the security requirements of EU’s Restricted VoIP protocol. This thesis investigates whether a software solution can provide the necessary levels of assurance to protect EU Restricted Voice over Internet Protocol (VoIP) communications. The thesis covers a literature study over possible approaches to protect sensitive information, which was used in the risk analysis to derive five tests to evaluate the trusted execution environment. The tests show that the trusted execution environment does provide good protection but that the implementation and design greatly influence the robustness and level of assurance that can be expected from the trusted execution environment.
APA, Harvard, Vancouver, ISO, and other styles
19

Sroka, Linda Marie Norfolk. "Fluid mixing with a side tee in straight and curved pipelines." Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/10085.

Full text
APA, Harvard, Vancouver, ISO, and other styles
20

Poore, Lois. "The Development of a Steel Embedded Connection for Double-Tee Beams." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/33041.

Full text
Abstract:
The research conducted was sponsored by JVI of Pittsfield, Massachusetts. JVI has developed a steel embedded connection, referred to as a shooter. The shooter is provided in capacities, a 40 kip capacity shooter and a 50 kip capacity shooter. This steel connection is embedded near the end of a double-tee prestressed girder. Double-tee prestressed girders are a primary component used in the construction of parking garages. Typical double-tee lengths are 60 to 75 feet; however, for this research 20 ft long segments were cast and tested with the shooter installed.

This project had three main goals. The first goal was to develop a preliminary design for the reinforcement around the shooter and test the shootersâ capacity in the laboratory to determine if the stated capacity was correct. Four different designs were created, two designs for the 40 kip capacity shooter and 2 designs for the 50 kip capacity shooter. Each design was placed in one stem of the double-tee and tested at the laboratory. Results from these tests indicate that that each specimen achieved the stated capacity. However, failure was not a connection failure but a shear bond failure.

The second goal was to take the information gathered from testing and develop a design model that could be used for other situations for this type of connection. The design model was created according to the guidelines in the ACI 318-08 code. Two different methods were used, a strut-and-tie model and a modified ACI code approach. From these designs it was determined that the strut-and-tie model should be used for the design of these connections; however, more research needs to be done before using the modified ACI code approach.

The final goal was to determine if finite element analysis could be used to determine if the load at which large cracks that immediately proceed failure occur could be predicted. From this analysis it was determined that a load range could be predicted in which a crack could form as well as a range of what the transfer length of the strands could be.
Master of Science

APA, Harvard, Vancouver, ISO, and other styles
21

Crispino, Eric Daniel. "Anchorage Zone Design for Pretensioned Bulb-Tee Bridge Girders in Virginia." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/31454.

Full text
Abstract:
Precast/Prestressed concrete girders are commonly used in bridge construction in the United States. The application and diffusion of the prestress force in a pretensioned girder causes a vertical tension force to develop near the end of the beam. Field surveys of the beam ends of pretensioned bridge girders indicate that many of the PCBT beams used in the Commonwealth of Virginia develop cracks within the anchorage zone region. The lengths and widths of these cracks range from acceptable to poor and in need of repair. Field observations also indicate deeper cross sections, very heavily prestressed sections, and girders with lightweight concrete tend to be most susceptible to crack formation. This research examined a new strut-and-tie based design approach to the anchorage zone design of the PCBT bridge girders used in Virginia. Case study girders surveyed during site visits are discussed and used to illustrate the nature of the problem and support the calibration of the strut-and-tie based model. A parametric study was conducted using this proposed design model and the results of this study were consolidated into anchorage zone design tables. The results of the parametric study were compared to the results obtained using existing anchorage zone design models, international bridge codes, and standard anchorage zone details used by other states. A set of new standard details was developed for the PCBT girders which incorporates elements of the new design approach and is compatible with the anchorage zone design aids. A 65 ft PCBT-53 girder was fabricated to verify the new strut-and-tie based design model. This girder contained anchorage zone details designed with the new model. The new anchorage zone details were successful at controlling the development of anchorage zone cracks. The new design approach is recommended for implementation by the Virginia Department of Transportation.
Master of Science
APA, Harvard, Vancouver, ISO, and other styles
22

Otegui, Michael A. "Simplified method for design of stiffened and unstiffened structural tee hangers." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-10022008-063105/.

Full text
APA, Harvard, Vancouver, ISO, and other styles
23

Hofer, Christine [Verfasser]. "Einfluss von Tee-Polyphenolen auf die Endothelfunktion beim Menschen / Christine Hofer." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2017. http://d-nb.info/1133493181/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
24

Earl, Jacqueline Sonia. "The influence of hygrothermal ageing on polymeric composite sandwich materials and structures." Thesis, University of Southampton, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342836.

Full text
APA, Harvard, Vancouver, ISO, and other styles
25

Hochmuth, Christian. "Globale Güter - lokale Aneignung Kaffee, Tee, Schokolade und Tabak im frühneuzeitlichen Dresden." Konstanz UVK-Verl.-Ges, 2008. http://d-nb.info/988912287/04.

Full text
APA, Harvard, Vancouver, ISO, and other styles
26

Tee, Hisaschi [Verfasser]. "Polyphosphoesters: A degradable alternative to polyolefins and poly(ethylene glycol) / Hisaschi Tee." Mainz : Universitätsbibliothek Mainz, 2019. http://d-nb.info/1185605630/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
27

Thräne, Claudia [Verfasser]. "Untersuchungen zum Vorkommen von Nicotin in Tee und teeähnlichen Erzeugnissen / Claudia Thräne." München : Verlag Dr. Hut, 2015. http://d-nb.info/1080754644/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
28

Powelson, Phillip. "Prestress Losses and Temperature Effects on a Deck Bulb Tee Girder Bridge." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/5396.

Full text
Abstract:
The Utah Transportation Center (UTC), in partnership with the Mountain Plains Consortium (MPC), sponsored a study to investigate the differences in prestress losses and temperature gradients in a concrete deck bulb tee girder bridge. The Millville Bridge was built as an access point to the Ridgeline High School in Millville, Utah. The bridge was built in 2016 and presently supports two lanes of traffic. Changes in prestress were measured with a total of 16 vibrating wire strain gauges located at four cross-sections. Temperature gradients were measured with a total of 50 thermocouples located at five cross-section locations, four of which were shared locations with the vibrating wire strain gauges. These instruments were placed at the mid-span and end of an exterior and center girder to effectively measure the bridge response in one quarter of the bridge superstructure. These instruments were placed in the precast plant and tied to the reinforcing steel before the concrete was poured. The prestress loss recordings were initiated before the prestressing strands were released. The thermocouple data for Girder 1 began to be recorded before the initial casting of the girder concrete. The thermocouple data for Girder 5 was not recorded during casting and curing of the girder concrete, but was started before the curing blanket was removed in the casting yard. All data was recorded until February 29, 2016. Prestress losses at the girder mid-span and temperature gradients were compared with code recommended values according to the AASHTO bridge design specifications.
APA, Harvard, Vancouver, ISO, and other styles
29

Malan, Wynand Louis. "Design, modelling and control of CLC Tee-Resonant Dual Active Bridge Converters." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/200329/1/Wynand_Malan_Thesis.pdf.

Full text
Abstract:
Tee-Resonant Dual Active Bridges are isolated, bidirectional, DC-DC converters that behave as voltage-controlled current sources, which makes them especially useful for battery charging applications. In this work, three new phase-shift modulation strategies are proposed that can improve the converter efficiency at high switching frequencies and enable loss-shifting between the primary and secondary sides. To model the converter, a large signal state-space model is derived and it is demonstrated to be useful for controller design. Lastly, a converter topology is proposed that enables direct integration of the converter with the grid, including power factor correction capability.
APA, Harvard, Vancouver, ISO, and other styles
30

Friedrich, Maika. "Wirkung von Teecatechin Epigallocatechingallat auf den Energiestoffwechsel der Maus." Phd thesis, Universität Potsdam, 2010. http://opus.kobv.de/ubp/volltexte/2010/4815/.

Full text
Abstract:
Die gesundheitsfördernden Eigenschaften von grünem Tee sind weitgehend akzeptiert. Den Teecatechinen, insbesondere dem Epigallocatechin-3-gallat (EGCG), werden zahlreiche positive Effekte zugesprochen (z. B. antioxidativ, antikanzerogen, antiinflammatorisch, Blutdruck und Cholesterinspiegel senkend). Die Mechanismen, die zu einer Reduktion der in Tierversuchen beschriebenen Körper- und Fettmasse führen, sind nicht ausreichend geklärt. Ziel dieser Arbeit bestand darin, die kurz- und mittelfristigen Wirkungen einer TEAVIGO®-Applikation (mind. 94 % EGCG) am Mausmodell im Hinblick auf den Energie- und Fettstoffwechsel sowie die Expression daran beteiligter Gene in wichtigen Organen und Geweben zu untersuchen. In verschiedenen Tierversuchen wurde männlichen C57BL/6-Mäusen eine Hochfettdiät (HFD) mit und ohne Supplementation (oral, diätetisch) des entkoffeinierten Grüntee-Extraktes TEAVIGO® in unterschiedlichen Dosierungen gefüttert. Es wurden sowohl kurz- als auch mittelfristige Wirkungen des EGCG auf die Energiebilanz (u. a. indirekte Tierkalorimetrie) und Körperzusammensetzung (NMR) sowie die exogene Substratoxidation (Stabilisotopentechnik: Atemtests, Inkorporation natürlicher 13C-angereicherter Triglyceride aus Maiskeimöl in diverse Organe/Gewebe) und Gen-expression (quantitative real-time PCR) untersucht. Die Applikationsform und ihre Dauer riefen unterschiedliche Wirkungen hervor. Mäuse mit diätetischer Supplementation zeigten bereits nach kurzer Zeit eine verminderte Körperfettmasse, die bei weiterer Verabreichung auch zu einer Reduktion der Körpermasse führte. Beide Applikationsformen resultieren, unabhängig von der Dauer der Intervention, in einer erhöhten Energieausscheidung, während die Futter- und Energieaufnahme durch EGCG nicht beeinflusst wurden. Der Energieverlust war von einer erhöhten Fett- und Stickstoffausscheidung begleitet, deren Ursache die in der Literatur beschriebene Interaktion und Hemmung digestiver Enzyme sein könnte. Besonders unter postprandialen Bedingungen wiesen EGCG-Mäuse erniedrigte Triglycerid- und Glycogengehalte in der Leber auf, was auf eine eingeschränkte intestinale Absorption der Nährstoffe hindeutet. Transkriptanalysen ergaben im Darm eine verminderte Expression von Fettsäuretransportern, während die Expression von Glucosetransportern durch EGCG erhöht wurde. Weiterhin reduzierte EGCG, nach Umstellung von Standard- auf eine maiskeimölhaltige Hochfettdiät, die Inkorporation natürlicher 13C-angereicherter Triglyceride in diverse Organe und Gewebe – insbesondere Leber, viszerales und braunes Fettgewebe sowie Skelettmuskel. Die Analyse der 13C-Anreicherung im Atem der Mäuse und die Energieumsatzmessungen ergaben nach kurzer Applikation eine erhöhte Fettoxidation, die im weiteren Verlauf der Intervention auf eine erhöhte Kohlenhydratoxidation umgeschaltet wurde. Weiterhin war die orale Applikation von EGCG bei gleichzeitiger Fütterung einer Hochfettdiät von makroskopischen und mikroskopischen degenerativen Veränderungen der Leber begleitet. Diese Effekte wurden nach diätetischer Supplementation der Hochfettdiät mit EGCG nicht beobachtet. Zusammenfassend zeigen die Ergebnisse, dass die Körpergewichts- und Fettgewebs-abnahme durch diätetisches EGCG sich durch eine herabgesetzte Verdaulichkeit der Nahrung erklären lässt. Dies führte zu verschiedenen kurz- und mittelfristigen Veränderungen in der Fettverteilung und im Fettmetabolismus.
The health-promoting properties of green tea are widely accepted. Tea catechins, particularly epigallocatechin-3-gallate (EGCG), are attributed to many positive effects (anti-oxidative, anti-cancerogen, anti-inflammatory, blood pressure and cholesterol lowering). Mechanisms leading to a reduction of body mass and fat mass in animal experiments are not fully elucidated. The aim of this study was to examine multiple effects of TEAVIGO® application (at least 94% EGCG) in a mouse model in terms of energy and fat metabolism. Expressions of genes involved in these processes were also determined in different organs and tissues. In several animal studies, male C57BL/6 mice were fed a high fat diet supplemented with decaffeinated TEAVIGO® (oral, dietetic) at different dosages. Short- and medium-term effects of EGCG were investigated on energy balance (indirect animal calorimetry), body composition (NMR), exogenous substrate oxidation (stable isotopes: breath tests, incorporation of naturally 13C-enriched triglycerides from corn oil into various organs/tissues), and gene expression (quantitative real-time PCR). Type of application and its duration elicited different effects. Supplemented mice already showed a reduced body fat mass after short- and medium-term treatment. Further administration lead to a reduction of body weight. Regardless of the duration of intervention, both types of application resulted in an increased energy excretion, while food and energy intake was not affected by EGCG. Fecal energy loss was accompanied by an increased fat and nitrogen excretion, which was probably due to an inhibition of digestive enzymes. Fed mice displayed a decreased triglyceride and glycogen content in liver suggesting a reduced absorption of nutrients in the intestine. This was supported by a decreased expression of intestinal fatty acid transporters. However, expression of glucose transporters was increased after short- and medium term application. Furthermore, EGCG attenuated incorporation of naturally 13C-enriched triglycerides into various organs and tissues – particularly liver, visceral and brown adipose tissue, and skeletal muscle. Analysis of 13C-enrichment in breath and measurement of energy expenditure revealed an initial increased fat oxidation, which was switched to an increased carbohydrate oxidation over time. Besides, a combination of oral administration of EGCG and high fat feeding was accompanied by macroscopic and microscopic deleterious changes in liver. These effects were not observed after dietary supplementation of EGCG. Altogether, reduction in body mass and fat mass by EGCG can be explained by a decreased food digestibility leading to various short- and medium-term changes in fat distribution and lipid metabolism.
APA, Harvard, Vancouver, ISO, and other styles
31

Higgins, Adam. "Design of all-bolted extended double angle, single angle, and tee shear connections." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0009361.

Full text
APA, Harvard, Vancouver, ISO, and other styles
32

El-Shaboury, Ahmed M. F. "Two-phase flow in horizontal impacting tee junctions, current state of the art." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0014/MQ53152.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
33

Arirachakaran, Srihasak. "Two-phase slug flow splitting phenomenon at a regular horizontal side-arm tee /." Access abstract and link to full text, 1990. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/9111868.

Full text
APA, Harvard, Vancouver, ISO, and other styles
34

Kang, Chew Ting. "Ultimate strength of Double-Tee tubular joints under combined brace and chord loading." Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364210.

Full text
APA, Harvard, Vancouver, ISO, and other styles
35

Megow, Inna [Verfasser]. "Der Einfluss von grünem Tee auf das antioxidative Potential der Haut / Inna Megow." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2021. http://d-nb.info/1241540527/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
36

Urban, Janka [Verfasser]. "Vergleich von grünem und schwarzem Tee auf NO-Produktion und Endothelfunktion / Janka Urban." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2009. http://d-nb.info/1023697076/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
37

El-Tattan, Anuar. "Erstellung eines Marketingkonzepts für die Nutzung eines ehemaligen TEE-Triebwagens (BR VT 601)." Institut für Transportwirtschaft und Logistik, WU Vienna University of Economics and Business, 2008. http://epub.wu.ac.at/810/1/document.pdf.

Full text
Abstract:
This diploma thesis analyzes and evaluates potential utilization scenarios for a former Trans Europ Express VT 601, the flagship of the German Federal Railways from the fifties to the late eighties. The introduction of the Trans Europ Express (TEE) ushered in a new era of Intra-European passenger traffic and was the beginning of increased private and business travel mainly between the founding countries Germany, Italy, France, Suisse and the Netherlands. Because of its outstanding performance, comfort and reliability the TEE upheld its enormous popularity for more than thirty years of use before it was replaced by the Eurocity (EC) in 1987. Today, 50 years after its maiden trip, the last remaining privately held TEE VT 601 is intended to be recreated as a luxury train in a new design. For this purpose, this work investigates alternative stationary and mobile utilization scenarios and assesses them from a financial and qualitative point of view. The results show potential weaknesses of this project primarily because of the high costs involved in the restructuring process. Furthermore a recommended strategic course of action is given in order to provide the involved decision-makers with appropriate ideas of how to successfully establish a strong position in the luxury travel market. (author's abstract)
Series: Schriftenreihe des Instituts für Transportwirtschaft und Logistik - Verkehr
APA, Harvard, Vancouver, ISO, and other styles
38

Lindelöf, Linnea. "Bedömning av etiologi till mitralisinsufficiens med 2DTEE vs. 3DTEE : En jämförande studie mellan oerfaren och erfaren ekokardiograför." Thesis, Umeå universitet, Biomedicinsk laboratorievetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-103672.

Full text
APA, Harvard, Vancouver, ISO, and other styles
39

Ferreira, Ana Filipa Roque de Jesus. "Projeto de campos de golfe municipais. Aplicação prática no município de Santarém." Master's thesis, ISA/UTL, 2012. http://hdl.handle.net/10400.5/5464.

Full text
Abstract:
Mestrado em Arquitectura Paisagista - Instituto Superior de Agronomia
In Portugal, for many, golf is still considered an elitist sport. This is due to the fact that in our country, until recently there were only top golf courses, usually associated with resorts where the fee that is paid for a round of golf this modality becomes inaccessible to much of the population. Such is not the case in other countries, such as UK, France or even our neighboring Spain, where there are infrastructure less showy, but with usage fees considerably lower than the municipal golf courses. Presently there are two municipal golf courses operating in the country, one in Cantanhede and the other in Jamor. These are the first contributions to that golf can be practiced by anyone regardless of their economic circumstances. This thesis is divided into four chapters. The first one is an introductory chapter to golf, speaking a bit of its history, as the field is made, some principles of the game and golf in Portugal, in order to introduce the concepts discussed in the thesis. The second chapter is about the architecture of golf courses in general, speaking of its historical evolution, the basic criteria for the design of a course and site selection, as do the design of the course of play, and then more specifically in the design of a golf hole, also the design of each of the components of the golf hole. The third chapter is already more specific municipal golf courses, introducing this concept, the existing typologies, the aspects to consider when designing a municipal golf course and existing examples in our country, which is the case with Jamor, Cidade universitária and Cantanhede. Finally, the fourth chapter deals with the practical application of this study to the municipality of Santarém. To this end, a territorial analysis is made to Santarém, selected a site for the project and this landscape is analyzed in order to better understand the dynamic nature of the site, allowing a map synthesis ability of the territory each component the golf course. From this overview map of suitability is then done the preliminary design of the golf course. This study is intended as a contribution to the dissemination of municipal golf courses, studying its architecture and all aspects to take into consideration as well as the specific characteristics in relation to a municipal golf course. This study also aims to contribute to the architecture landscape design of golf courses, including the analysis of the local landscape. The practical application of this thesis aims at a project that is both efficient in terms of play and follow the practices used in golf course architecture, but also respecting the territory and its surroundings and all associated natural dynamics.
APA, Harvard, Vancouver, ISO, and other styles
40

Menninger, Annerose. "Genuss im kulturellen Wandel Tabak, Kaffee, Tee und Schokolade in Europa (16. - 19. Jahrhundert)." Stuttgart Steiner, 2003. http://d-nb.info/98747474X/04.

Full text
APA, Harvard, Vancouver, ISO, and other styles
41

Mwakali, Jackson Aarali. "The collapse behaviour of double-layer space trusses incorporating eccentrically loaded tee-section members." Thesis, University of Surrey, 1990. http://epubs.surrey.ac.uk/756/.

Full text
APA, Harvard, Vancouver, ISO, and other styles
42

Menninger, Annerose. "Genuss im kulturellen Wandel : Tabak, Kaffee, Tee und Schokolade in Europa (16.-19. Jahrhundert) /." Stuttgart : F. Steiner, 2004. http://catalogue.bnf.fr/ark:/12148/cb39985913v.

Full text
APA, Harvard, Vancouver, ISO, and other styles
43

Raghavan, Ashwin Ph D. Massachusetts Institute of Technology. "Numerical simulations of supercritical water-hydrocarbon mixing in a 3-D cylindrical tee mixer." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/87965.

Full text
Abstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 167-171).
Supercritical water upgrading and desulfurization (SCWUDS) is a new concept in the oil refining industry wherein, crude oil is mixed with supercritical water in a reactor leading to chemical breakdown of the sulfur containing compounds (desulfurization) and cracking of long chain hydrocarbons to shorter chain compounds closer to commercial fuel components (upgrading). The focus of the present work is the development of a numerical tool to investigate the mixing of water and hydrocarbons under supercritical fully-miscible conditions (water and hydrocarbon forming a single phase) in a realistic 3-D cylindrical tee mixer geometry so as to develop an understanding of the effects of geometry, flow rates and fluid properties on the mixing dynamics which in turn will influence the rate of thermal cracking reactions of hydrocarbons and organosulfur compounds as well as the final product distributions. This work includes a consistent treatment of near-critical thermodynamics and transport property variations of real fluid mixtures. A Peng-Robinson EoS with simple van der Waals mixing rules is employed to model the near-critical thermodynamic behavior, with the mixture binary interaction parameter obtained from a Predictive Peng-Robinson approach using a group contribution method (PPR78). A 2nd order accurate finite-volume methodology is used for the numerical solution of the conservation equations. The developed numerical tool was used to investigate the mixing of supercritical water and a model hydrocarbon (n-decane) in a small-scale cylindrical tee mixer (pipe ID = 2.4mm) under fully miscible conditions. For a Reynolds number at the water inlet of 500 and a [delta]T between the two streams of l00K (Tw,in = 800K, Td,in= 700K), the flow downstream of the mixing joint remained laminar. Most of the mixing and heat transport occurs due to the circulating action of a counter-rotating vortex pair (CVP) in the hydrocarbon jet formed due to the reorientation of the vorticity preexisting in the hydrocarbon stream flowing through the vertical pipe. This CVP gets progressively weaker as it is advected downstream, due to vorticity diffusion and species and heat transport is dominated by molecular diffusion over small length scales in the far downstream region. Consequently, the mixing rate plateaus in the far downstream region of the tee mixer. Near-critical property variations were found to have a negligible impact on the flow field and mixing behavior under these conditions. However, for a 300K temperature difference between the two streams (Tw,in = 1000K, Td,in = 700K), the water-HC shear layer becomes unstable and rolls up downstream of 5 diameter lengths from the mixing joint. The onset of instability in the shear layer also triggers the stretching and breakdown of the hydrocarbon jet CVP leading to a significant enhancement in mixing manifested as a jump in the mixing rate and a thickening of the mean mixing layer. However, water n-decane mixing under identical inlet conditions but with constant physical properties, showed a stable shear layer with the flow reaching steady state. For a large [delta]T between the streams of 300K, the strong density increase (due to cooling of the water component) and the strong viscosity decrease (due to heating of the n-decane component) leads to a local increase in the Re within the mixing layer, resulting in the instability of the shear layer. SCW n-decane mixing with [delta]T = l00K was also simulated for increasingly higher Reynolds numbers up to the transition to turbulence. When the Reynolds number at the water inlet is increased to 700, the shear layer between the water and n-decane streams is found to become unstable near x = 6D downstream of the mixing joint followed by the subsequent roll up of the shear layer. The local increase of Re within the mixing layer due to mechanisms similar to the [delta]T = 300K case was found to be the cause of the shear layer instability. At Rew,in = 800 the unsteady small scale flow structures in the mixing layer and the consequent flow field fluctuations due to them are much stronger. The stretching and breakdown of the CVP in this case, is accompanied by stronger streamwise vorticity enhancement resulting in much faster mixing compared to the case of Rew,in = 700.
by Ashwin Raghavan.
S.M.
APA, Harvard, Vancouver, ISO, and other styles
44

Torres, Victor J. "Live Load Testing and Analysis of a 48-Year-Old Double Tee Girder Bridge." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/4962.

Full text
Abstract:
A 48-year-old prestressed double tee girder bridge located on Icy Springs road in Coalville, Utah, was tested for live load. The test measured strains, deflections and rotations. The instruments used for measuring the respective measurements were strain gages, deflectometers ("twangers") and tiltmeters. From the recorded measurements a finite element model (FEM) was calibrated to validate the modeling techniques based on the test data. The FEM implemented two joint link elements to connect the flanges of the FEM deck to model the transverse load distribution of the bridge deteriorated shear connectors. The abutment restraints were modeled by one joint link elements. The deck and the stems were modeled using shell element. After validating the modeling techniques, a parametric study was developed to study the prediction of FEM girder distribution factors (GDF). The FEM GDF predictions were compared to the prediction proposed by the American Association of State Highway and Transportation Officials (AASHTO) in the provision AASHTO LRFD 2010. The parametric study considered the variable parameters of span length, slab thickness, number of double tees, angle of skew, and stem spacing. The AASHTO specification provides an inaccurate prediction, therefore a new statistical model was proposed to better predict GDF. Furthermore, rating factors based on different girder distribution factors were studied for the Icy Springs bridge. The bridge has a passing rate for operating level.
APA, Harvard, Vancouver, ISO, and other styles
45

Wishart, Cornelia. "Measurement of total body water (TBW) and total energy expenditure (TEE) using stable isotopes." Thesis, Queensland University of Technology, 2011. https://eprints.qut.edu.au/44135/1/Cornelia_Wishart_Thesis.pdf.

Full text
Abstract:
Understanding the relationship between diet, physical activity and health in humans requires accurate measurement of body composition and daily energy expenditure. Stable isotopes provide a means of measuring total body water and daily energy expenditure under free-living conditions. While the use of isotope ratio mass spectrometry (IRMS) for the analysis of 2H (Deuterium) and 18O (Oxygen-18) is well established in the field of human energy metabolism research, numerous questions remain regarding the factors which influence analytical and measurement error using this methodology. This thesis was comprised of four studies with the following emphases. The aim of Study 1 was to determine the analytical and measurement error of the IRMS with regard to sample handling under certain conditions. Study 2 involved the comparison of TEE (Total daily energy expenditure) using two commonly employed equations. Further, saliva and urine samples, collected at different times, were used to determine if clinically significant differences would occur. Study 3 was undertaken to determine the appropriate collection times for TBW estimates and derived body composition values. Finally, Study 4, a single case study to investigate if TEE measures are affected when the human condition changes due to altered exercise and water intake. The aim of Study 1 was to validate laboratory approaches to measure isotopic enrichment to ensure accurate (to international standards), precise (reproducibility of three replicate samples) and linear (isotope ratio was constant over the expected concentration range) results. This established the machine variability for the IRMS equipment in use at Queensland University for both TBW and TEE. Using either 0.4mL or 0.5mL sample volumes for both oxygen-18 and deuterium were statistically acceptable (p>0.05) and showed a within analytical variance of 5.8 Delta VSOW units for deuterium, 0.41 Delta VSOW units for oxygen-18. This variance was used as “within analytical noise” to determine sample deviations. It was also found that there was no influence of equilibration time on oxygen-18 or deuterium values when comparing the minimum (oxygen-18: 24hr; deuterium: 3 days) and maximum (oxygen-18: and deuterium: 14 days) equilibration times. With regard to preparation using the vacuum line, any order of preparation is suitable as the TEE values fall within 8% of each other regardless of preparation order. An 8% variation is acceptable for the TEE values due to biological and technical errors (Schoeller, 1988). However, for the automated line, deuterium must be assessed first followed by oxygen-18 as the automated machine line does not evacuate tubes but merely refills them with an injection of gas for a predetermined time. Any fractionation (which may occur for both isotopes), would cause a slight elevation in the values and hence a lower TEE. The purpose of the second and third study was to investigate the use of IRMS to measure the TEE and TBW of and to validate the current IRMS practices in use with regard to sample collection times of urine and saliva, the use of two TEE equations from different research centers and the body composition values derived from these TEE and TBW values. Following the collection of a fasting baseline urine and saliva sample, 10 people (8 women, 2 men) were dosed with a doubly labeled water does comprised of 1.25g 10% oxygen-18 and 0.1 g 100% deuterium/kg body weight. The samples were collected hourly for 12 hrs on the first day and then morning, midday, and evening samples were collected for the next 14 days. The samples were analyzed using an isotope ratio mass spectrometer. For the TBW, time to equilibration was determined using three commonly employed data analysis approaches. Isotopic equilibration was reached in 90% of the sample by hour 6, and in 100% of the sample by hour 7. With regard to the TBW estimations, the optimal time for urine collection was found to be between hours 4 and 10 as to where there was no significant difference between values. In contrast, statistically significant differences in TBW estimations were found between hours 1-3 and from 11-12 when compared with hours 4-10. Most of the individuals in this study were in equilibrium after 7 hours. The TEE equations of Prof Dale Scholler (Chicago, USA, IAEA) and Prof K.Westerterp were compared with that of Prof. Andrew Coward (Dunn Nutrition Centre). When comparing values derived from samples collected in the morning and evening there was no effect of time or equation on resulting TEE values. The fourth study was a pilot study (n=1) to test the variability in TEE as a result of manipulations in fluid consumption and level of physical activity; the magnitude of change which may be expected in a sedentary adult. Physical activity levels were manipulated by increasing the number of steps per day to mimic the increases that may result when a sedentary individual commences an activity program. The study was comprised of three sub-studies completed on the same individual over a period of 8 months. There were no significant changes in TBW across all studies, even though the elimination rates changed with the supplemented water intake and additional physical activity. The extra activity may not have sufficiently strenuous enough and the water intake high enough to cause a significant change in the TBW and hence the CO2 production and TEE values. The TEE values measured show good agreement based on the estimated values calculated on an RMR of 1455 kcal/day, a DIT of 10% of TEE and activity based on measured steps. The covariance values tracked when plotting the residuals were found to be representative of “well-behaved” data and are indicative of the analytical accuracy. The ratio and product plots were found to reflect the water turnover and CO2 production and thus could, with further investigation, be employed to identify the changes in physical activity.
APA, Harvard, Vancouver, ISO, and other styles
46

Dong, Fangxiao. "KINETICS OF WEDGE-TEE JOINT FORMATION DURING BRAZING OF AN ALUMINUM ALLOY UNDER CONTROLLED ATMOSPHERE." UKnowledge, 2013. http://uknowledge.uky.edu/me_etds/23.

Full text
Abstract:
This work involves investigation of the kinetics data of a joint formation during aluminum alloy brazing. Data was generated by several groups of experiments conducted under conditions of a controlled oxygen level of the background brazing atmosphere. Generated data are examined to identify the phases of the joint formation and the time frame of its evolution. Specifically, the triple line kinetics data are analyzed to verify whether a power law between (1) the triple line of the molten metal preceding joint formation and (2) the formation time can be established for each formation phase. In addition, both initial and residual clad thicknesses on brazing sheets are studied to check phenomenologically an impact of silicon diffusion on joint formation. Formation shapes are also inspected in order to study if a 2-D configuration of joint formation is present. The kinetics data from different sets of experiments under adverse atmosphere conditions are compared to understand the impact of oxygen level on joint formation. This study is not necessarily aimed at building a mathematical model for T-Joint formation during brazing process, but intends to understand possible influential parameters on the development of the formation. KEYWORDS: Aluminum Brazing, Kinetics, T-Joint, Background Atmosphere, Capillary Flow.
APA, Harvard, Vancouver, ISO, and other styles
47

Meinardus, Pamela [Verfasser]. "Flavonoidgehalt in der Muttermilch nach Intervention mit einem Sojagetränk oder entkoffeiniertem schwarzen Tee / Pamela Meinardus." Bonn : Universitäts- und Landesbibliothek Bonn, 2012. http://d-nb.info/1043055177/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
48

Sprunger, W. Frederic. "An evaluation of proposals made in TEE in Japan following a decade of ministry involvement." Theological Research Exchange Network (TREN), 1992. http://www.tren.com.

Full text
APA, Harvard, Vancouver, ISO, and other styles
49

Kopec, David M., James H. Walworth, Jeffrey J. Gilbert, Greg M. Sower, Mohammed Pessarakli, D. Kerr, and J. Spense. "Response of Sea Isle I Paspalum to Fertilization and Mowing for Tee and Fairway Turf." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/216542.

Full text
APA, Harvard, Vancouver, ISO, and other styles
50

Bouazzouni, Mohamed Amine. "Processus sécurisés de dématérialisation de cartes sans contact." Phd thesis, Toulouse, INPT, 2017. http://oatao.univ-toulouse.fr/19488/1/BOUAZZOUNI_MohamedAmine.pdf.

Full text
Abstract:
Au fil des années, la technologie sans contact NFC s'est imposée dans notre quotidien au travers des différents services proposés. Les cas d'utilisation sont nombreux allant des cartes de fidélité, des cartes de transport, des cartes de paiement sans contact jusqu'aux cartes de contrôle d'accès. Cependant, les premières générations des cartes NFC ont une sécurité minimale reposant sur l'hypothèse de leur non-clonabilité. De multiples vulnérabilités ont été découvertes et leur exploitation a permis des copies frauduleuses. Afin de remédier à ces vulnérabilités, une nouvelle génération de cartes à la sécurité augmentée a vu le jour. Ces cartes permettent une authentification avec un lecteur basée sur des algorithmes de chiffrements symétriques tels qu'AES, DES, et 3DES. Elles sont plus robustes que la première génération mais ont subi des également une attaque en reverse-engineering. Pour garantir et améliorer le niveau de sécurité du système de contrôle d'accès, nous proposons dans le cadre de l'opération neOCampus, la dématérialisation sécurisée de la carte sans contact sur un smartphone muni de la technologie NFC. Cette dématérialisation nous permet d'exploiter la puissance de calcul et la capacité de stockage du smartphone afin de déployer des algorithmes d'authentification plus robustes. Cependant, l'OS du smartphone ne peut être considéré comme un environnement de confiance. Afin de répondre à la problématique du stockage et du traitement sécurisés sur un smartphone, plusieurs solutions ont été proposées : les Secure Elements (SE), les Trusted Platform Module (TPM), les Trusted Execution Environment (TEE) et la virtualisation. Afin de stocker et de traiter de manière sécurisée les données d'authentification, le TEE apparait comme la solution idéale avec le meilleur compromis sécurité/performances. Cependant, de nombreux smartphones n'embarquent pas encore de TEE. Pour remédier à cette contrainte, nous proposons une architecture basée sur l'utilisation de TEEs déportés sur le Cloud. Le smartphone peut le contacter via une liaison Wi-Fi ou 4G. Pour se faire, un protocole d'authentification basé sur IBAKE est proposé. En plus de ce scénario nominal, deux autres scenarii complémentaires ont été proposés permettant d'accompagner le développement et la démocratisation des TEE non seulement dans le monde des smartphones mais aussi sur des dispositifs peu onéreux comme le Raspberry Pi 3. Ces architectures déploient le même algorithme d'authentification que le scénario nominal. Nous proposons aussi une architecture hors ligne permettant à un utilisateur de s'authentifier à l'aide d'un jeton de connexion en cas d'absence de réseaux sans fil. Cette solution permet de relâcher la contrainte sur la connectivité du smartphone à son Cloud. Nous procédons à une évaluation de l'architecture de dématérialisation et de l'algorithme d'authentification en terme de performances et de sécurité. Les opérations cryptographiques du protocole d'authentification sont les plus coûteuses. Nous avons alors procédé à leur évaluation en nous intéressant en particulier aux opérations de chiffrement IBE et à la génération de challenges ECC. Nos implémentations ont été évaluées pour l'infrastructure Cloud et l'environnement mobile. Nous avons ensuite procédé à une validation du protocole d'authentification sur les trois architectures sélectionnées à l'aide de l'outil Scyther. Nous avons montré, que pour les trois scenarii, la clé de session négociée via le protocole d'authentification restait secrète durant tout le protocole. Cette caractéristique nous garantit que les données d'authentification chiffrées avec cette clé resteront secrètes et que la phase d'identification de la personne est protégée tout en préservant l'ergonomie du système existant.
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography