Residual Strength after Fatigue of Unidirectional and Cross-Ply Metal Matrix Composites at Elevated Temperature

This study investigated the residual strength of the unidirectional and cross-ply laminates of SCS-6 / Ti-15-3, metal matrix composite at elevated temperature 427°C (800°F) after under tension-tension load controlled mode. For this purpose, several specimens were fatigued to various fractions of the fatigue life and then loaded monotonically to failure. The purpose of this study was to determine the effects of different levels of fatigue damage on the composite\u27s strength. The unidirectional specimens were cycled at a 900 MPa maximum stress at a frequency of 10 Hz, while, the cross-ply specimens were tested at both 300 MPa and 450 MPa at 5 Hz and 10 Hz, respectively. The residual strength results for the three cases showed similar trends in that residual strength drop with cycles was small until near the end of the fatigue life. Both the unidirectional and cross-ply specimens demonstrated only a small drop of the residual strength with cycles until near the end of the fatigue life

Development of Information Technology Auditing Teaching Modules: An Interdisciplinary Endeavor between Seidenberg and Lubin Faculty

The original goals of the project were to develop interdisciplinary Information Technology (IT) Auditing teaching modules, to be integrated into courses offered by both Business and Information Technology disciplines during Fall 2009 and Spring 2010. IT Auditing is an interdisciplinary field which requires understanding audit, control, technology and security concepts in accordance with audit standards, guidelines, and best practices. Thus, IT Auditing requires interdisciplinary knowledge across IT and Accounting/Auditing domains. With increasing use of IT in business processes, the demand for IT Auditors is increasing rapidly, offering a lucrative career path. Acquiring IT Audit related knowledge and skills will help our students improve their career opportunities by exploring this growing field. Based upon the curriculum content areas of the CISA Exam as well as the ISACA Model Curriculum, we proposed the following three interdisciplinary teaching modules for IT Auditing: 1) IT Auditing Frameworks & Business Continuity; 2) IT Lifecycle Management & Service Delivery; and 3) Protection of Information Assets. We had developed the three teaching modules. Each individual module can be covered in one to two weeks. The entire set of three IT Auditing modules can then be covered in 3-4 weeks of class time. For each of the individual modules, we had developed presentation slides, reading lists and online quizzes based on the CISA Exam. We had also identified an overarching case study to be used throughout the three individual modules for continuity reasons

A phenomenology analysis of the tachyon warm inflation in loop quantum cosmology

We investigate the warm inflation condition in loop quantum cosmology. In our consideration, the system is described by a tachyon field interacted with radiation. The exponential potential function, V(\phi)=V_0 e^{-\alpha\phi}\label{exp-p}, with the same order parameters $V_0$ and $\alpha$, is taken as an example of this tachyon warm inflation model. We find that, for the strong dissipative regime, the total number of e-folds is less than the one in the classical scenario, and for the weak dissipative regime, the beginning time of the warm inflation will be later than the tachyon (cool) inflation.Comment: 7 pages,accepted for publication in Physics Letters

A simplified guide ruler from numeric table method in doing rotational osteotomy

<p>Abstract</p> <p>Background</p> <p>Čobeljić et al. recently reported a numeric table method to provide precise rotational osteotomy which is a well established orthopaedic procedure. The numeric table requires four pages in length that is rather inconvenient during performing an osteotomy operation. </p> <p>Methods</p> <p>We thus develop our own method by summarizing the data of the four-page table into a small ruler, which is easy to carry and use in operation room. An electrical version of this ruler is also available. We also build a computer model to verify Čobeljić et al. method.</p> <p>Results</p> <p>The error of Čobeljić et al. is between -37% to 16% (mean ± SD = -6% ± 9%). We verify our ruler by calculating the absolute difference between our method and that of Čobeljić et al. The difference is less than 0.1 mm.</p> <p>Conclusion</p> <p>Our ruler is convenient for practical use for the rotational osteotomy procedure with equal precision. Further clinical verification is needed to justify its real significance.</p

Evaluation of Seismic Rupture Models for the 2011 Tohoku-Oki Earthquake Using Tsunami Simulation

Developing a realistic, three-dimensional rupture model of the large offshore earthquake is difficult to accomplish directly through band-limited ground-motion observations. A potential indirect method is using a tsunami simulation to verify the rupture model in reverse because the initial conditions of the associated tsunamis are caused by a coseismic seafloor displacement correlating to the rupture pattern along the main faulting. In this study, five well-developed rupture models for the 2011 Tohoku-Oki earthquake were adopted to evaluate differences in simulated tsunamis and various rupture asperities. The leading wave of the simulated tsunamis triggered by the seafloor displacement in Yamazaki et al. (2011) model resulted in the smallest root-mean-squared difference (~0.082 m on average) from the records of the eight DART (Deep-ocean Assessment and Reporting of Tsunamis) stations. This indicates that the main seismic rupture during the 2011 Tohoku earthquake should occur in a large shallow slip in a narrow range adjacent to the Japan trench. This study also quantified the influences of ocean stratification and tides which are normally overlooked in tsunami simulations. The discrepancy between the simulations with and without stratification was less than 5% of the first peak wave height at the eight DART stations. The simulations, run with and without the presence of tides, resulted in a ~1% discrepancy in the height of the leading wave. Because simulations accounting for tides and stratification are time-consuming and their influences are negligible, particularly in the first tsunami wave, the two factors can be ignored in a tsunami prediction for practical purposes

Air and Steam Gasification of Almond Biomass

Experiments were performed on a laboratory scale fluidized bed gasifier to characterize the gasification products of almond shell and hull removed in nut processing operations and to determine the effect of gasifying media on bed agglomeration. The higher heating value of syngas during air gasification of almond biomass ranged from 4 to 6 MJ m(-3) while gas concentrations ranged from 14 to 18% H-2, 3-4% CH4, 43-50% N-2, 16-19% CO, and 16-17% CO2. For steam gasification, higher heating value was 10-12 MJ m(-3) and gas concentrations were 35-40% H-2, 5-7% CH4, 17-21% N-2, 18-21% CO, and 16-18% CO2. The high level of potassium in the almond shells led to strong corrosion and bed agglomeration due to flue gas transport of potassium compounds. These resulting pervasive kalsilite reactions were significantly worse under air gasification than under steam gasification. As a result of prolonged duration and elevated temperature approaching 1,000 degrees C, the corrosinal reaction changes to formation of an adhesive potassium distillate melt locally forming strong bonds. This latter is interpreted as a result of aerosol transported of melt particles.California Energy Commission [PIR-07-002, PIR-11-008]; Almond Board of California; USDA-NIFA/UC Agricultural Experiment Station; California Almond Hullers and Processors AssociationThis work was supported by the California Energy Commission [PIR-07-002 and PIR-11-008]. We also acknowledge the generous support of the Almond Board of California, the California Almond Hullers and Processors Association, and USDA-NIFA/UC Agricultural Experiment Station

Dipole-Deformed Bound States and Heterotic Kodaira Surfaces

We study a particular N = 1 confining gauge theory with fundamental flavors realised as seven branes in the background of wrapped five branes on a rigid two-cycle of a non-trivial global geometry. In parts of the moduli space, the five branes form bound states with the seven branes. We show that in this regime the local supergravity solution is surprisingly tractable, even though the background topology is non-trivial. New effects such as dipole deformations may be studied in detail, including the full backreactions. Performing the dipole deformations in other ways leads to different warped local geometries. In the dual heterotic picture, which is locally given by a C* fibration over a Kodaira surface, we study details of the geometry and the construction of bundles. We also point out the existence of certain exotic bundles in our framework.Comment: 40 pages, 3 .eps figures, Harvma

Assessment of hypermucoviscosity as a virulence factor for experimental Klebsiella pneumoniae infections: comparative virulence analysis with hypermucoviscosity-negative strain

<p>Abstract</p> <p>Background</p> <p><it>Klebsiella pneumoniae </it>displaying the hypermucoviscosity (HV) phenotype are considered more virulent than HV-negative strains. Nevertheless, the emergence of tissue-abscesses-associated HV-negative isolates motivated us to re-evaluate the role of HV-phenotype.</p> <p>Results</p> <p>Instead of genetically manipulating the HV-phenotype of <it>K. pneumoniae</it>, we selected two clinically isolated K1 strains, 1112 (HV-positive) and 1084 (HV-negative), to avoid possible interference from defects in the capsule. These well-encapsulated strains with similar genetic backgrounds were used for comparative analysis of bacterial virulence in a pneumoniae or a liver abscess model generated in either naïve or diabetic mice. In the pneumonia model, the HV-positive strain 1112 proliferated to higher loads in the lungs and blood of naïve mice, but was less prone to disseminate into the blood of diabetic mice compared to the HV-negative strain 1084. In the liver abscess model, 1084 was as potent as 1112 in inducing liver abscesses in both the naïve and diabetic mice. The 1084-infected diabetic mice were more inclined to develop bacteremia and had a higher mortality rate than those infected by 1112. A mini-Tn<it>5 </it>mutant of 1112, isolated due to its loss of HV-phenotype, was avirulent to mice.</p> <p>Conclusion</p> <p>These results indicate that the HV-phenotype is required for the virulence of the clinically isolated HV-positive strain 1112. The superior ability of the HV-negative stain 1084 over 1112 to cause bacteremia in diabetic mice suggests that factors other than the HV phenotype were required for the systemic dissemination of <it>K. pneumoniae </it>in an immunocompromised setting.</p

Gauge-Gravity Dualities, Dipoles and New Non-Kahler Manifolds

In this work we explore many directions in the framework of gauge-gravity dualities. In type IIB theory we give an explicit derivation of the local metric for five branes wrapped on rigid two-cycles. Our derivation involves various interplays between warp factors, dualities and fluxes and the final result confirms our earlier predictions. We also find a novel dipole-like deformation of the background due to an inherent orientifold projection in the full global geometry. The supergravity solution for this deformation takes into account various things like the presence of a non-trivial background topology and fluxes as well as branes. Considering these, we manage to calculate the precise local solution using equations of motion. We also show that this dipole-like deformation has the desired property of decoupling the Kaluza-Klein modes from the IR gauge theory. Finally, for the heterotic theory we find new non-Kahler complex manifolds that partake in the full gauge-gravity dualities and study the mathematical structures of these manifolds including the torsion classes, Betti numbers and other topological data.Comment: Harvmac, 80 pages, 4 .eps figures; v2: Some typos corrected and new references added; v3: More typos corrected and references updated. Final version to appear in Nucl. Phys.