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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.
101

The Lasting Impression of a President on the Supreme Court: FDR’s Judicial Legacy

Searls, Courtney K 01 January 2013 (has links)
After a full first term without any Supreme Court nominations, and almost no cooperation from the Court in regards to the New Deal, President Franklin D. Roosevelt decided to introduce a Court-packing plan into the Legislature that would allow him to add six new justices to the Court if necessary. The Bill failed in both the House and Senate but time allowed Roosevelt to have his chance to “pack” the court. Roosevelt nominated some of the best justices the Court has seen, and with their service the Supreme Court was forever changed.
102

A 3D Fold-Up Non-Classical Unipolar CMOS and Its Mechanism

Kuo, Chih-hao 30 July 2010 (has links)
In this thesis, we propose a three-dimensional (3D) fold-up non-classical unipolar complementary metal-oxide semiconductor field-effect transistor (CMOS-FET) structure and its operation mechanism. We utilize a NMOS transistor having punch-through effect and a classical NMOS to realize our proposed CMOS circuit. In our proposed CMOS circuit, both driver and load transistors are based on the n-channel MOS (NMOS) structures, so, in this unipolar CMOS, the carrier used is the electron only. Hence, the delay time can be improved by 14% when compared with the conventional CMOS. Moreover, the p-channel MOS (PMOS) transistor can be eliminated in our proposed CMOS circuit. Thus, we do not need the traditional N-well technique and we also use the 3D device architecture to drastically reduce the total device area more than 69%, in comparison to a conventional CMOS. If our proposed CMOS architecture is implemented in the VLSI circuits, the packing density can be increased and the device fabrication cost can also be reduced significantly. Therefore, our proposed 3D fold-up non-classical single-carrier CMOS-FET can achieve three important requirements as follows: 1) area reduction, 2) enhanced speed, and 3) decrease cost in the system fabrication.
103

Simulation and Fabrication of a Non-Classical Unipolar CMOS with Embedded Oxide

Sun, Chih-hung 30 July 2010 (has links)
In this paper, we propose a novel Unipolar CMOS device in which the transport carriers are electron only. And we achieve good inverter output waveform and logic circuit applications by simulation. Duo to all n-channel (NMOS) structures are used, we call this proposed CMOS as a Unipolar CMOS. A new basic theory of utilizing the punch through effect is demonstrated to enhance the tPLH in our proposed Unipolar CMOS. The average delay time compared with the classical CMOS circuit can be improved 23% for high-performance applications. For our proposed Unipolar CMOS, all n-channel MOS are used to eliminate the N- and P-well processes and ignore the difference between the carrier mobility. In addition, the common electrodes are also exploited, hence, the layout area can be reduced to about 75%, which leads to significantly increase the packing density of CMOS circuits in the same chip.
104

A Molecular Mechanics Knowledge Base Applied to Template Based Structure Prediction

Qu, Xiaotao 2009 December 1900 (has links)
Predicting protein structure using its primary sequence has always been a challenging topic in biochemistry. Although it seems as simple as finding the minimal energy conformation, it has been quite difficult to provide an accurate yet reliable solution for the problem. On the one hand, the lack of understanding of the hydrophobic effect as well as the relationship between different stabilizing forces, such as hydrophobic interaction, hydrogen bonding and electronic static interaction prevent the scientist from developing potential functions to estimate free energy. On the other hand, structure databases are limited with redundant structures, which represent a noncontinuous, sparsely-sampled conformational space, and preventing the development of a method suitable for high-resolution, high-accuracy structure prediction that can be applied for functional annotation of an unknown protein sequence. Thus, in this study, we use molecular dynamics simulation as a tool to sample conformational space. Structures were generated with physically realistic conformations that represented the properties of ensembles of native structures. First, we focused our study on the relationship among different factors that stabilize protein structure. Using a wellcharacterized mutation system of the B-hairpin, a fundamental building block of protein, we were able to identify the effect of terminal ion-pairs (salt-bridges) on the stability of the beta-hairpin, and its relationship with hydrophobic interactions and hydrogen bonds. In the same study, we also correlated our theoretical simulations qualitatively with experimental results. Such analysis provides us a better understanding of beta-hairpin stability and helps us to improve the protein engineering method to design more stable hairpins. Second, with large-scale simulations of different representative protein folds, we were able to conduct a fine-grained analysis by sampling the continuous conformational space to characterize the relationship among backbone conformation, side-chain conformation and side-chain packing. Such information is valuable for improving high-resolution structure prediction. Last, with this information, we developed a new prediction algorithm using packing information derived from the conserved relative packing groups. Based on its performance in CASP7, we were able to draw the conclusion that our simulated dataset as well as our packing-oriented prediction method are useful for template based structure prediction.
105

Molecular Packing in Crystalline poly(9,9-dialkyl-2,7-fluorene)s

Chou, Hung-Lung 28 July 2004 (has links)
Structural evolution and its effect on optical absorption/emission behavior of derivatives of PFs upon heat treatment at different temperatures were studies by means of a combination of x-ray diffraction, transmission electron microscopy and molecular simulation. The main physical characteristics from results of this study over a series of PFs with alkyl side-chains may be summarized as the following: (1) The crystal structure of poly (9,9-di-n-octyl- 2,7-fluorene, PF8) and poly(9,9-bis(2- ethylhexyl)- 2,7-fluorene, PF26) are determined via a combination of selected area electron diffraction and molecular simulation. In PF8 case, there are 8 chains in an orthorhombic unit cell with dimensions a = 2.56 nm, b = 2.34 nm, c (chain axis) = 3.32 nm, space group P212121, and calculated density of 1.041 gcm-3. On the other hand, in PF26 case, there are 3 chains in a trigonal unit cell with dimensions a = 1.67 nm, b = 1.67 nm, c (chain axis) = 4.04 nm, space group P3, and calculated density of 0.991 gcm-3. (2) All the simulation results indicate that branched side-chains in the case of PF26 tend to fill the space among backbones. In contrast, the linear side-chains in the case of PF8 appear to embrace the neighboring backbone, favoring formation of layered structure. (3) As a consequence, co-planrity of PF backbones is decreased by the attached alkyl side-chains. This in turn results in lowered conjugation length, and in favor of blue light emission.
106

The green process that¡¦s affect to the packing industry: The study of Orient Semiconductor Electronic,Ltd

Su, Chen-ping 05 February 2006 (has links)
The continuing of industrial revaluation and capitalism today are facing the most difficult enemy ever. 38 billion years of natural resources will be destroyed and over utilized within the next 10 years. The global business will be paying 1500 billion dollars to overcome the effect of changing wheather and natural environment especially those digital industry. The global high tech industry is having a ¡§Green colour¡¨ hits. It is not a war in invoice competition. It is a war for life. The continues of the technological advantages and fast development in industry, have bringing in a convenient life to human being but on the other hand it had introduced lots of troubles in our natural environment. The awareness of our natural environment began in 1970, the first ¡§Global Day¡¨ continues in 1972, Stockholm¡¦s environment and development conference, people begins their awareness of our natural environment, knowledge, understanding and its trouble. In August this year the European alliances will be announcing the three directions of the law in the waste of electrical engineering and facility and electrical facility and products awareness. Therefore the producers have to register their product before August this year. Which includes the digital produce company, products, after sales services and recycling business are all effected bye the law. The following trend of Green Process will be the next demand on industry generation. Under the green process direction, every products that produced have to be recyclable, Lead free, Halogen free . Therefore the trend will bring to a whole new revolution of digital industry. Taiwan¡¦s IC packing industry is one of the most important rule to be a part in global semiconductor. In order to be part of trend, and facing the changing environment, follow the flow is the only way to continue the business. Our aim for this research is to discover the green products¡¦ that¡¦s affect to the packing industry. Our research is hoping to discover a deep underneath for every cases of green process products changing and to the IC packing industry. We also hoping the research could analyze the future development of the green process environment.
107

Computational and experimental investigations of forces in protein folding

Schell, David Andrew 17 February 2005 (has links)
Properly folded proteins are necessary for all living organisms. Incorrectly folded proteins can lead to a variety of diseases such as Alzheimer’s Disease or Bovine Spongiform Encephalitis (Mad Cow Disease). Understanding the forces involved in protein folding is essential to the understanding and treatment of protein misfolding diseases. When proteins fold, a significant amount of surface area is buried in the protein interior. It has long been known that burial of hydrophobic surface area was important to the stability of the folded structure. However, the impact of burying polar surface area is not well understood. Theoretical results suggest that burying polar groups decreases the stability, but experimental evidence supports the belief that polar group burial increases the stability. Studies of tyrosine to phenylalanine mutations have shown the removal of the tyrosine OH group generally decreases stability. Through computational investigations into the effect of buried tyrosine on protein stability, favorable van der Waals interactions are shown to correlate with the change in stability caused by replacing the tyrosine with phenylalanine to remove the polar OH group. Two large-scale studies on nearly 1000 high-resolution x-ray structures are presented. The first investigates the electrostatic and van der Waals interactions, analyzing the energetics of burying various atom groups in the protein interior. The second large-scale study analyzes the packing differences in the interior of the protein and shows that hydrogen bonding increases packing, decreasing the volume of a hydrogen bonded backbone by about 1.5 Å3 per hydrogen bond. Finally, a structural comparison between RNase Sa and a variant in which five lysines replaced five acidic groups to reverse the net charge is presented. It is shown that these mutations have a marginal impact on the structure, with only small changes in some loop regions.
108

Photophysics of bis(diarylamino)biphenyl dyes adsorbed on silver nanoparticles

Haske, Wojciech 18 May 2010 (has links)
This dissertation investigates the photophysics of bis(diarylamino)biphenyl (TPD) and silver nanoparticles (AgNP). A main goal of this work was to develop an understanding of the relaxation pathways involved in the deactivation of photoexcited TPD chromophores in close proximity to silver nanoparticles. The TPD chromophores were attached to the silver nanoparticle core via an alkylthiol group. The TPD-AgNP systems were synthesized and characterized using Transmission Electron Microscopy (TEM), UV-visible absorption, infrared spectroscopy, and Nuclear Magnetic Resonance (NMR) spectroscopy, Inductively Coupled Plasma - Emission Spectroscopy (ICP-ES) and Thermogravimetric Analysis (TGA). Time-resolved photophysical processes in these systems were studied using femtosecond transient absorption spectroscopy. Initial studies of the interaction of the TPD and AgNP addressed the linker length dependence of the dye excited state decay kinetics, wherein alkyl linker chains of 3, 4, 8 and 12 carbon atoms were used. These results showed that an ultrafast deactivation of the excited state of the TPD chromophore, which is three orders of magnitude faster than that of the free chromophore in solution, occurred in all of the systems. However, an unexpected new transient species was observed for the systems with three and four carbon linker chains. Further studies showed this species to be spectroscopically very similar to the TPD radical cation, suggesting a charge separation pathway in the excited state relaxation. Possible pathways for formation of the cation-like state were examined through comparisons to the photophysics of alkyl substituted TPD in solution and in solid films, investigation of the pulse energy and TPD surface coverage dependence of the yield of the cation-like TPD species, transient absorption anisotropy decay dynamics, and kinetic modeling studies. Taken together, these investigations provide support for exciton-exciton annihilation being responsible for the formation of cation-like species. The packing of the TPD chromophores is concluded to be of critical importance in the generation of the cation like species but it is also possible that proximity to the silver nanoparticle plays a role in facilitating charge separation as well.
109

The influence of particle shape of coating pigments on their packing ability and on the flow properties of coating colours

Lohmander, Sven January 2000 (has links)
<p>The influence of particle shape of coating pigments on theirpacking ability and on the flow properties of coating colourshas been investigated. The particle shapes considered werespherical, flaky and acicular (needle-shaped). In the case ofsuspensions containing monodisperse spherical polystyreneparticles, a concentration gradient appeared in the filter cakeforming during filtration under static conditions. Such agradient, monitoredby non-destructive magnetic resonanceimaging (MRI), is not accounted for in the traditionalfiltration theory used in coating technology. Good agreementwas found between a literature model describing filtrationthrough a compressible filter cake and the concentrationgradients measured by MRI. According to this model, the scaledconcentration gradient was the same at all times.</p><p>For flaky (mainly kaolin) and acicular (aragonite)particles, a rapid method was evaluated to estimate a shapefactor of the pigment particle. Generalised mathematical modelsof oblate and prolate spheroids were applied to reduce thethree geometrical dimensions of the particle to two, the majoraxis and the minor axis. The shape factor, which is mass-based,was derived from a comparison between the results obtained bytwo different size-assessment instruments, viz. the Sedigraphand an instrument using light scattering. This yields a shapefactor distribution as a function of equivalent sphericalparticle size, but the results are uncertain for small particlediameters, below 0.2 µm. Good agreement was obtainedbetween the shape factor and a mass-based aspect ratio obtainedby image analysis, but the rapid method is generally moreaccurate for flaky than for acicular particles.</p><p>Results obtained by capillary viscometry showed that therewas a relationship between the viscosity at high shear rates(>10<sup>5</sup>s<sup>-1</sup>) and the shape factor, but that it was notsufficient to use the median value of the shape factor toachieve proper information. A more complete evaluation requiresknowledge of the shape factor distribution, which is also givenin part by the method mentioned above. However, a large medianshape factor was related to a high high-shear viscosity.Non-Newtonian entrance pressure losses were sometimessignificant in capillary viscometry, indicating that it wasinappropriate to measure the shear viscosity with only onecapillary. Such effects were however relatively much morepronounced in slit die viscometry, especially in the case ofacicular particles, where the aspect ratio was a crucialparameter. The influence of the shape factor of kaolinparticles on the non-Newtonian entrance pressure losses over aslit die was surprisingly small. The high-shear viscosity ofcoating suspensions based on different pigments correlated withthe median pore size of the corresponding coating layer ratherthan with the porosity.</p><p><b>Keywords</b>: Aspect ratio, capillary viscometry, coatingcolour, filtration, particle packing, pigment, pore structure,rheology, shape factor, slit die viscometry, spheroid.</p>
110

Boosting Lunch Is In The Bag

Almansour, Fawaz 20 August 2015 (has links)
Lunch Is In The Bag (LIITB) was a multi-level behavioral intervention with the goal of increasing the amounts of fruits, vegetables, and whole grains that parents pack in their preschoolers' lunches. The purpose of this dissertation project was to: 1) to examine the temperatures of perishable food items packed in preschoolers' sack lunches; 2) to examine parents' psychosocial constructs that relate to packing fruits, vegetables, and whole grains at four periods during the booster study; 3) to assess the servings of fruits, vegetables, and whole grains with the related nutrient content at four periods during the booster study. The four assessment periods are before LIITB, after LIITB, before the one-week booster, and after the one-week booster. Results showed that more than 97 percent of perishable food items in the sack lunches were stored at unacceptable temperatures (40-140°F). Servings of vegetables (-0.15, p=0.05) and whole grains (-0.53, p<0.0001) in preschool lunches decreased significantly before the booster in the intervention group. The booster increased the servings of vegetables (0.10, p=0.09) and whole grains (0.16, p =0.01) compared to booster baseline. The one-week booster increased thiamin, dietary fiber, and vitamin C content of foods in preschoolers' lunches. During the booster study, parents experienced improvement in psychosocial variables after LIITB and before the booster. Knowledge decreased before the booster. Parents' psychosocial variables were linked to packing more vegetables and significantly more whole grains due to the intervention. Education for parents and the public must focus on methods of packing safe, healthy lunches in order to prevent foodborne illness and chronic disease. The results of this study provide data for continued examination of an area of parental behavior related to packing lunches for their children. The booster study demonstrated that a booster was important for maintenance of program outcomes, and to increase the servings of vegetables and whole grains that parents packed in their preschool children's lunches. / text

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