Dissertations

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17b-Estradiol is Abundant in Skin and Regulates the Hair Follicle Cycle and Mirex Tumor Promotion
(2002-01-07) Porter, Karen; Robert C. Smart, Chair; C. Lee Robinette, Co-chair; Ronald Baynes, member; Gerald A. LeBlanc, member
Skin is a complex, hormone responsive tissue that functions as a barrier against water loss and infection. Estrogens have been shown to influence dermal thickness, vasodilatation and hair growth in skin. Remarkably, cutaneous E2 levels and capacity for E2 synthesis have not been fully assessed. We have determined that cutaneous17b-estradiol (E2) levels average nine times greater than serum E2 levels in female mice and that skin E2 is independent of serum E2. Additionally, we determined that estrogens are a major metabolite of testosterone in mouse skin explants, indicating that skin is a major site of extraglandular estrogen biosynthesis. Earlier studies have shown that castration accelerates hair growth in mice, and we have determined that castration induces a greatly diminished telogen phase, of the hair cycle. Previously our laboratory has shown that E2 blocks telogen to anagen transition of the hair cycle. We observed that only twice weekly 1 nmol E2 treatment reversed the effects of castration while daily treatment with 100 nmol testosterone or 25 nmol DHT was required, indicating that E2 is up to 100 times more potent than androgens. Previous studies have shown that mirex, a non-phorbol ester skin tumor promoter, promotes three times more tumors in female mice than OVX mice. E2 implants were able to restore 80% of the intact female mirex promotion response to OVX mice, indicating that E2 is the primary ovarian hormone that regulates mirex promotion. Since mirex promotes three times more tumors in female mice than in male mice, we conducted a tumor promotion study on intact and castrate mice given empty or E2 containing implants, and found that intact mice develop three times more tumors than castrated mice and that E2 implants fully restore intact male response to castrate mice, indicating that E2 also regulates mirex tumor promotion sensitivity in male mice. Collectively, these data indicate that skin is an important extraglandular source of E2 and skin E2 influences the hair cycle and chemical carcinogenesis.
19Ne Excited States and Resonances in the 18F(p,α)15O Reaction in Classical Novae.
(2022-02-16) Portillo Chaves, Federico Exeario; Richard Longland, Chair; Albert Young, Member; James Kneller, Member; Robert Janssens, Inter-Institutional; Ethan Hyland, Graduate School Representative
2D Human Pose Estimation by Integrating Convolutional Neural Networks and Structural Information.
(2019-11-06) Dong, Liang; Tianfu Wu, Co-Chair; Min Chi, Co-Chair; Edgar Lobaton, Member; Christopher Healey, Member
3-D Microstructure Creation Using Elliptical Vibration-Assisted Machining (EVAM).
(2014-06-26) Brehl, David Edward; Thomas Dow, Chair; Ronald Scattergood, Member; Paul Ro, Member; Gregory Buckner, Member
3-D Prismatic Packaging Methodologies for Wide Band Gap Power electronics Modules
(2017-09-15) Ke, Haotao; Douglas Hopkins, Chair; Subhashish Bhattacharya, Member; B. Baliga, Member; Ola Lars Harrysson, Member
3-tier Service Level Agreement with Automatic Class Upgrades
(2006-04-12) Haddad, Reda Nassif; Yannis Viniotis, Committee Chair
Tremendous efforts have been spent on devising mechanisms that would provide Quality of Service (QoS) needed by various applications, and network operators have spent a lot of resources trying to fit their networks with differentiated services capabilities. One of the Service Level Agreements (SLA) promising to sell these QoS services is the "triple play" SLA, bundling 3 classes of services targeting voice, data and video. In particular, circuit switched network operators envision the triple play SLA as essential to revenue maintenance, customer retention, and growth. It is their way, through the IP Multimedia Subsystem (IMS) standardization for example, to move all non-IP current and future services, such as voice, onto IP. In this thesis, we propose a "3-tier SLA with automatic class upgrades", an enhancement to the triple play SLA, in that it automatically upgrades lower classes' packets to fill gaps or unused bandwidth in the upper classes. The proposed SLA incorporates a scalable solution to the reordering problem, caused by upgrading lower class-packets to upper classes; the solution does not require per flow state information. We provide a thorough analysis of the QoS performance in terms of goodput, losses and delay of both UDP and TCP sources and show that the proposed SLA maximizes the customer's utilization of the reserved and paid-for bandwidth by maximizing the utilization of the most expensive, better service, upper QoS classes, and provides much greater throughput than the proposed "triple play" model.
3D Integral Invariant Signatures And Their Application on Face Recognition
(2007-09-17) Feng, Shuo; Hamid Krim, Committee Chair; Irina Kogan, Committee Member; Michael Escuti, Committee Member; Griff Bilbro, Committee Member
Curves are important features in computer vision and pattern recognition, and their classification under a variety of transformations, such as Euclidean, affine or projective, poses a great challenge. Invariant features of these curves turn out to be crucial to simplifying any classification procedure. This, as a result, has recently led to a renewed research interest in transformation invariants. In this thesis, new explicit formulae for integral invariants for curves in 3D with respect to the special and the full affine groups are presented.The development of the 3D integral invariant are based on an inductive approach in terms of Euclidean invariants. For the first time, a clear geometric interpretation of both 2D and 3D integral invariants is presented. Since integration attenuates the effects of noise, integral invariants have advantages in computer vision applications. We use integral invariants to construct global and local signatures that characterize curves up to the special affine transformations, subsequently extended to the full affine group. Global Signatures are independent of parameterization, and Local Signatures are independent of both parameterizationa and initial point selection. We analyze the robustness of these invariants in their application to the problem of classification of noisy spatial curves extracted as characteristics from a 3D object. Our investigation of 2D and 3D integral invariants and signatures, originally motivated by Biometrics applications, are successfully implemented and applied to face recognition to eliminate the effects of pose and facial expression. A high recognition performance rate of 95% is achieved in the test with a large face data set.
3D Nanofabrication Using AFM-Based Ultrasonic Vibration Assisted Nanomachining.
(2017-07-18) Deng, Jia; Jingyan Dong, Co-Chair; Paul Cohen, Co-Chair; Chih-Hao Chang, Minor; Yuan-Shin Lee, Member; Consuelo Arellano, Graduate School Representative
3D Patterning of Ultralight Porous Metal Oxide/MWCNT Macro-Structures And Their Applications.
(2018-08-20) Aksu, Cemile; Philip Bradford, Co-Chair; Jesse Jur, Co-Chair; Michael Dickey, Member; Xiangwu Zhang, Member
3D Structures formed by a Robotic and Meltblowing Integrated System
(2003-04-09) Velu, Yogeshwar Karunakaran; Abdelfattah M. Seyam, Committee Co-Chair; Tushar K. Ghosh, Committee Co-Chair; Behnam Pourdeyhimi, Committee Member; Marcia L. Gumpertz, Committee Member; Martin W. King, Committee Member; Donald A. Shiffler, Committee Member
Meltblown nonwovens have been produced as 2D web structures for a variety of end uses. Investigation into the development of 3D structures, has led to the integration of meltblown and robotic technology to form the Robotic Fiber Assembly and Control System. The effects of various process parameters including the fiber stream approach angle and the curvature of the collecting surface on the structural properties of the webs such as the diameter and orientation distribution of the fibers and the pore size distribution on the webs has been investigated. The interrelationships between these structural parameters have been explored and a statistical model developed. Orientation distribution, and the fiber diameter distribution of the webs were measured on image analysis software, while the pore size distribution was measured using equipment developed on the basis of capillary flow technique. SAS was used to develop the correlations between the structural parameters of the web. In general, all the webs show a larger percentage of fibers orienting in the machine direction (MD). The webs with finer fiber diameter produced webs with smaller pore diameter. The take-up speed of the collector had a significant influence on the orientation and diameters of the fibers in the web. Finer fibers were formed which are more oriented in the machine direction as the take-up speed of the collecting surface increased resulting in the formation of a web which has pores with finer diameter. A decrease in the polymer throughput demonstrated a decrease in the fiber diameter, the pore diameter and the basis weights of the webs. The resulting webs also produced pores that are of finer diameter. Lower attenuating air pressures produced larger diameter fibers. The average pore diameter of the analyzed meltblown fabrics decreased significantly when the attenuating air pressure was increased. Increasing the die to collector distance (DCD) shows a decrease in the percentage of fibers that are oriented in the machine direction. An increase in the DCD also exhibits an initial decrease followed by an increase in the average pore size confirming the existence of different 'zones' in the space between the die and collector. The increase in fiber stream approach angle shows an initial decrease followed by significant increase in the pore size of the web. Compared to the webs formed at low approach angles, analyses of the webs formed at higher approach angles shows that the fibers are more randomly arranged at higher approach angles. The relative frequency of fiber oriented in the machine direction increased significantly when the curvature of the collecting surface increases while the average pore size of the web decreases, due to the increased orientation of fibers in the direction of collection. The pore diameter is found to be directly proportional to the fiber diameter and inversely related to the web anisotropy parameter. The relationship that was established for the 2D webs correlates to the relationship developed for the 3D web structures.
3D-Bioplotted Scaffold for Autograft Substitution in Osteochondral Plug Transfer Approaches: Design and Process Characterization.
(2018-05-10) Huebner Dos Reis, Pedro; Rohan Shirwaiker, Chair; Richard Wysk, Member; Ola Lars Harrysson, Member; Matthew Fisher, Minor; Maria Avramova, Graduate School Representative
3D-DATE: A Circuit-Level Three-Dimensional DRAM Area, Timing, and Energy Model.
(2018-04-20) Park, Jong Beom; Paul Franzon, Co-Chair; William Davis, Co-Chair; James Tuck, Member; Hans Hallen, Member
4H-SiC Trench-Gate MOSFET: Practical Surface-Channel Mobility Extraction.
(2019-08-23) Harmon, Jeffrey Lee; B. Baliga, Chair; Stephen Michielsen, Graduate School Representative; John Muth, Member; John Veliadis, Member; Veena Misra, Member
7.2 kV Solid State Transformer Based on 15 kV SiC MOSFETs and A Novel Single Stage AC-AC Converter
(2017-12-08) Zhu, Qianlai; Alex Huang, Chair; Wensong Yu, Member; Srdjan Lukic, Member; Xiangwu Zhang, Member
90nm CMOS Direct-Conversion Transmitter Design For WCDMA
(2009-03-11) Yang, Xuemin; Kevin G. Gard, Committee Chair; Antonio J. Montalvo, Committee Member; Paul D. Franzon, Committee Member; Maysam Ghovanloo, Committee Member; D. Troy Case, Committee Member
Over the last decade, third-generation (3G) cellular networks have been undergoing tremendous development to meet an increasing demand for better quality and higher speed wireless services. Silicon germanium (SiGe) bipolar CMOS (BiCMOS) has been the dominant process technology for RF transceivers of cellular systems. However, in recent years, there is increasing interest to implement RF transceivers using advanced submicron CMOS technology driven by the demand for high-volume and low-cost solutions. One big challenge for designing a CMOS WCDMA direct conversion transmitter is to meet the demand for both good linearity and good power efficiency. As opposed to constant envelop modulation adopted in GSM system, WCDMA employs HPSK modulation technique which presents better spectral efficiency but results in variable envelop modulation. Hence, linear amplification is required for WCDMA transmitter. Typically, power efficiency is traded for linearity performance. However, for cellular systems, low power solution is highly desirable for maximum usage of battery life. The goal of this research is to design a CMOS WCDMA transmitter with high power efficiency that is comparable to the SiGe BiCMOS counterpart while meeting the tough linearity specification. In this thesis, a third-order intermodulation distortion (IMD) cancelation technique is developed to design a high power efficiency, highly linear operation and large output power transmitter for WCDMA systems. The third-order IMD cancelation approach is realized by using a two-stage driver amplifier, where amplifiers at the two stages amplifier generate opposite distortions and cancel each other. In this work, the nonlinearity of a CMOS common source amplifier is comprehensively investigated to set a solid ground for directing the design of two-stage driver amplifier with third-order IMD cancelation. One big challenge of two-stage driver amplifier with third-order IMD cancelation is how to maintain the third-order IMD cancelation over process and temperature variations. In this thesis, the required condition to realize third-order IMD cancelation is discussed over process and temperature variations, and the design criteria for achieving the third-order IMD cancelation over process and temperature variations are presented.
A Biocomposite Biocatalyst for Energy Efficient Gas-to-Liquid Conversion of Carbon Monoxide by Clostridium ljungdahlii OTA1.
(2016-07-21) Schulte, Mark Joseph; Michael Flickinger, Chair; Steven Peretti, Member; Harold Lamb, Minor; Amy Grunden, Minor
A Braided Scaffold for Rotator Cuff Tissue Engineering.
(2022-08-17) Huang, Yihan; Martin King, Co-Chair; Jacqueline Cole-Husseini, Co-Chair; Edwin R. Cadet, Technical Consultant; Matthew Fisher, Minor; Sonja Salmon, Member; Jessica Gluck, Member
A Case Study Examining Perceptions of Postsecondary Career and Technical High-Risk Education Instructors within the North Carolina Community College System.
(2023-07-21) Gray, Jarvis K; James Bartlett, Chair; Michelle Bartlett, Member; Travis Park, Member; Alex Albert, Member
A Case Study Exploring Perspectives of Community College Experiences’ Role on Soft Skills Development of North Carolina Students Enrolled in Career and Technical Programs.
(2020-03-18) Lewis-Sessoms, Micara; James Bartlett, Chair; Michelle Bartlett, Member; Travis Park, Member; Carrol Adams Warren, Member
A Case Study of Nutrition Educators’ Perspectives on the Delivery of Virtual Community Nutrition Programming.
(2023-03-03) Anderson, Alyssa Nicole; Susan Barcinas, Chair; Mattie Fleener, Member; Duane Akroyd, Member; Susan Braithwaite, Member; Angela Smith, Member

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