Selective Laser Sintering of Zirconia with Micro-Scale Features

Recent work in Selective Laser Sintering of ceramics at the University of Texas at Austin demonstrates the capability to produce zirconia parts with fine features. Zirconia powder was pre-processed into spherical particles, laser sintered with a sacrificial polymer binder, infiltrated and post-sintered to higher density. Optical micrographs show that hole sizes of 180 /-tm are possible in fully ceramic components.Mechanical Engineerin

Functionally Gradient Material Design and Modeling Using Hypertexture for Solid Freeform Fabrication

SFF technologies have the potential to become manufacturing process that are capable of producing parts that have not been feasible by other techniques. The fabrication of Functionally Gradient Material (FGM) is one of the possible candidate. It is critical.to provide three dimensional material gradient data in the solid model to fabricate FGM. The approach is to model spatially varying material density distribution on implicit solid geometry using a hypertexturing scheme and a procedural volumetric modeling. It is essentially an extension of procedural solid texture synthesis, which has been effectively used to model cloud, gas, and flow stream. It will save the amount of information storage especially when the gradient pattern is repeating. Geometric operation becomes convenient since the material data are linked to the geometry only by the reference surfaces.Mechanical Engineerin

Quantum protocols for anonymous voting and surveying

We describe quantum protocols for voting and surveying. A key feature of our schemes is the use of entangled states to ensure that the votes are anonymous and to allow the votes to be tallied. The entanglement is distributed over separated sites; the physical inaccessibility of any one site is sufficient to guarantee the anonymity of the votes. The security of these protocols with respect to various kinds of attack is discussed. We also discuss classical schemes and show that our quantum voting protocol represents a N-fold reduction in computational complexity, where N is the number of voters.Comment: 8 pages. V2 includes the modifications made for the published versio

Compositional disorder and its influence on the structural, electronic and magnetic properties of MgC(Ni_{1-x}Co_{x})_{3} alloys using first-principles

First-principles, density-functional based electronic structure calculations are carried out for MgC(Ni_{1-x}Co_{x})_{3} alloys over the concentration range 0\leq x\leq1, using Korringa-Kohn-Rostoker coherent-potential approximation (KKR CPA) method in the atomic sphere approximation (ASA). The self-consistent calculations are used to study the changes as a function of x in the equation of state parameters, total and partial densities of states, magnetic moment and the on-site exchange interaction parameter. To study the magnetic properties as well as its volume dependence, fixed-spin moment calculations in conjunction with the phenomenological Landau theory are employed. The salient features that emerge from these calculations are (i) a concentration independent variation in the lattice parameter and bulk modulus at x~0.75 with an anomaly in the variation of the pressure derivative of bulk modulus, (ii) the fixed-spin moment based corrections to the overestimated magnetic ground state for 0.0\leq x\leq0.3 alloys, making the results consistent with the experiments, and (iii) the possibility of multiple magnetic states at x~0.75, which, however, requires further improvements in the calculations

Roux-en-Y Gastric Bypass Surgery Regulates Mitochondrial Dynamics Proteins in Primary Human Myotubes Derived from Severely Obese Humans

Mitochondrial dynamics including mitochondrial fission (e.g., Dynamin-related protein 1 (Drp1) and Fission 1 (Fis1)) and fusion (e.g., Mitofusin 2 (MFN 2)) regulates mitochondrial homeostasis. Defects in mitochondrial dynamics are suggested to contribute to skeletal muscle mitochondrial dysfunction and insulin resistance associated with severe obesity. Roux-en-Y gastric bypass (RYGB) surgery markedly improves metabolic health as indicated by enhanced substrate oxidation and insulin action in skeletal muscle. However, the underlying cellular mechanisms responsible for these are unclear and could possibly be due to the improvement of mitochondrial dynamics. PURPOSE: The purpose of this study was to determine whether RYGB surgery improves mitochondria dynamics proteins in primary human myotubes from severely obese humans. METHODS: Primary skeletal muscle cells were isolated from muscle biopsies obtained from six lean subjects (BMI = 23.4 ± 0.6 kg/m2) and six RYGB patients prior to, 1-month and 7-months after surgery (BMI = 50.2 ± 2.0, 43.2 ± 2.8 and 35.7 ± 2.2 kg/m2, respectively) and were differentiated to myotubes. On day 7 of differentiation, myotubes were harvested for further assessing the expressions of mitochondria dynamics proteins. RESULTS: Before surgery, Drp1Ser616 phosphorylation and Fis1 expression were significantly higher in myotubes derived from severely obese patients when compared to lean controls (41% and 26%, respectively, P \u3c 0.05). While there were no improvements at 1-month post-surgery, Drp1Ser616 phosphorylation and Fis1 expression were significantly decreased in myotubes from severely obese humans at 7-months post-surgery (Pre vs. 7-months post: 0.046 ± 0.004 vs. 0.035 ± 0.003; 0.023 ± 0.008 vs. 0.014 ± 0.003 AU; respectively, P \u3c 0.05), and not statistically different from lean controls. However, MFN2 expression did not change post-surgery in comparison to pre-surgery. CONCLUSION: These data suggest that RYGB surgery reduces obesity-induced rise in mitochondrial fission, but not fusion in primary human myotubes derived from severely obese humans

Beyond Attitudes: Attachment and Consumer Behavior

Although attachment theorists have examined the attachment concept in diverse relationship contexts (romantic relationship, kinship, and friendship, etc.), the nomological network of the construct has not been fully delineated. The purpose of the present paper is to develop this nomological network. We define brand attachment as the strength of the cognitive and emotional bond connecting the brand with the self. This definition involves two unique and essential elements: (1) connectedness between the brand and the self and (2) a cognitive and emotional bond, the strength of which evokes a readiness to allocate ones processing resources toward a brand. We examined factors that create brand attachment, the effects of brand attachment on higher order relationship-based exchange behaviors, why attachments (and hence relationships) weaken or terminate, and how they may be measured

A first-principles comparison of the electronic properties of MgC_{y}Ni_{3} and ZnC_{y}Ni_{3} alloys

First-principles, density-functional-based electronic structure calculations are employed to study the changes in the electronic properties of ZnC_{y}Ni_{3} and MgC_{y}Ni_{3} using the Korringa-Kohn-Rostoker coherent-potential approximation method in the atomic sphere approximation (KKR-ASA CPA). As a function of decreasing C at%, we find a steady decrease in the lattice constant and bulk modulus in either alloys. However, the pressure derivative of the bulk modulus displays an opposite trend. Following the Debye model, which relates the pressure derivative of the bulk modulus with the average phonon frequency of the crystal, it can thus be argued that ZnCNi_{3} and its disordered alloys posses a different phonon spectra in comparison to its MgCNi_{3} counterparts. This is further justified by the marked similarity we find in the electronic structure properties such as the variation in the density of states and the Hopfield parameters calculated for these alloys. The effects on the equation of state parameters and the density of states at the Fermi energy, for partial replacement of Mg by Zn are also discussed.Comment: 19 pages, 15 figure

What doesn’t kill me ... : adversity-related experiences are vital in the development of superior Olympic performance

Objectives: Recent research suggests that experiencing some adversity can have beneficial outcomes for human growth and development. The purpose of this paper was to explore the adversities that the world’s best athletes encounter and the perceived role that these experiences play in their psychological and performance development. Design: A qualitative design was employed because detailed information of rich quality was required to better understand adversity-related experiences in the world’s best athletes. Method: Semi-structured interviews were conducted with 10 Olympic gold medalists from a variety of sports. Inductive thematic analysis was used to analyze the data. Results: The findings indicate that the participants encountered a range of sport- and non-sport adversities that they considered were essential for winning their gold medals, including repeated non-selection, significant sporting failure, serious injury, political unrest, and the death of a family member. The participants described the role that these experiences played in their psychological and performance development, specifically focusing on their resultant trauma, motivation, and learning. Conclusions: Adversity-related experiences were deemed to be vital in the psychological and performance development of Olympic champions. In the future, researchers should conduct more in-depth comparative studies of Olympic athletes’ adversity- and growth-related experiences, and draw on existing and alternative theoretical explanations of the growth-performance relationship. For professional practitioners, adversity-related experiences offer potential developmental opportunities if they are carefully and purposely harnessed