Texas A&M University-Kingsville: AKM Digital Repository
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1689 research outputs found
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Modeling grace period policy in supercomputer systems using game-theoretic approach
No full textSupercomputers are employed for the execution of jobs that require considerably extensive computational resources. However, over or under-request job runtime has been observed in supercomputer systems, which drags down the scheduling performance. In order to maximize the performance of the supercomputers, users are encouraged to provide a more accurate estimate of the job runtime, and the service provider offers an appropriate amount of grace period. Data analysis of a supercomputer’s job runtime is conducted to show users’ behavioral patterns regarding runtime estimates. This study focuses on the design of a game model between the supercomputer service provider and users with the aim of finding the best grace-period level. In the proposed game-theoretic model, the grace period offered is the service provider’s decision variable. The user’s decision variable is the requested runtime deviation. The best response and Nash equilibrium condition for the service provider and the users are found. It is made apparent that the user’s runtime deviation directly affects the job scheduling reward for the service provider and the users. It is shown that under complete information between the service provider and users, the service provider can achieve higher reward of job scheduling when grace period is offered, and only a small number of jobs are terminated
Some mollusks of the Texas Coast
No full textA lack of information on classification and a personal interest in mollusks of the Texas coast has resulted in this study. The late Mr. John Kern Strecker, of Baylor University, Waco, Texas, has compiled the most complete checklist to date. The available data on the mollusks of this region is relatively scaroo. Four of the five classes of Mollusca, including seven orders, approximately fifty-five families and seventy-five genera are represented; however, this work is not as complete as the writer would like for it to be
Woodrow Wilson and the failure of world peace
No full textIn the decade proceeding the first World War the nations of Europe were engaged in a system of rival alliances designed to protect their national security and preserve the peace. This system of rival alliances was accompanied by conflicting interest in colonies and in trade, and many of the European nations were mailing a determined effort toward the realization of far reaching, imperialistic ambitions. Europe became a divided armed camp, and as military preparations continued the structure of European peace became increasingly unstable
Some phases of the development of the Texas transportation system
No full textTransportation has always held a vital place in the development of states and nations. In America as elsewhere, animal and Indian trails had marked the best routes for overland transportation when the white men appeared. These paths and trails could be used only by travelers on foot or at least at their best by horse-men and pack trains. When the need became sufficiently pressing, roads were out through the forest, streams were bridged and commerce was carried in wagons of various types drawn by oxen or horses. waterways were important as routes of travel from the early beginning. Canals were built in due time, and the canal boat, barge, flatboat, keelboat and canoe carried much of internal commerce of Texas numerous years ago. The steamboat largely supplanted other boats and carried a greatly increased tannage
Acoustic feedback (howling) in public address systems
No full textThere was once a man from Texas who, people said, used a "Hill Billy band" as a means to popularize himself and thereby win elections. Few people, however, realize that much of his success was due to his skill in the use of a public address system. Perhaps that is an art which has had a considerable amount of neglect
Dynamics of a semi-submersible offshore floating multi-wind-turbine platform
No full textThis research aims to design a novel semi-submersible platform for installing multiple turbines and analyze the aero-hydrodynamic responses of the platform operating under wind-wave conditions that can reduce the installation and mooring costs. The potential of wind power increases as we go further into the offshore. Extracting wind energy from offshore wind resources in deep water gives a chance to advance in expanding power generation from renewable resources. In this study, a review of the dynamics of existing floating platform concepts is investigated to evaluate the research gap to find a more effective platform for installing multiple wind turbines. The wake interference between the wind turbines on a multi-wind-turbine platform causes the performance drop in the downstream wind turbines hence, it is necessary to analyze the wake effects in the initial phase of the design. The wake effect analysis is performed using the Larsen wake model and CFD simulations on three probable platform choices to choose the best possible platform to design the multi-wind-turbine platform. The offshore floating platform studied in this report supports five 8 MW wind turbines. Hydrostatic analysis of the platform is done to study the floating stability behavior of the platform. The first order hydrodynamics and wave loadings on the platform are calculated in the frequency domain using the potential flow linear diffraction model. The hydrodynamic analysis is carried out on the platform to predict the wave-body interaction between the platform and the waves. The aero-hydrodynamic analysis of the multi-wind turbine platform has been carried out to comprehend the dynamic responses of the platform operating under coupled wind-wave loads. The aerodynamic loads due to wind speed on the wind turbines and hydrodynamic loads due to wind and waves on the overall system are evaluated. The dynamics of a wind turbine considering the five-degree of freedom are formulated and an adaptive control algorithm is developed for the pitch and torque control of the wind turbine. These dynamics are extended for the case of a multi-wind-turbine platform considering aerodynamics, hydrostatics, hydrodynamics, and mooring forces. The performance of the multi-turbine floater is evaluated by employing an adaptive blade pitch control to reduce the power fluctuations of the wind turbines
Investigation of the effect of simultaneous internal flow boiling and external condensation on the heat transfer performance under low pressure low flow conditions
No full textHeat exchangers used in thermal management systems have mostly been adopting a single-phase heat transfer process either at both sides or at one side while the other side is manipulated with a phase-change heat transfer process. However, the recent leap in heat dissipation rates, coupled with the need for size reduction of cooling hardware makes it impossible for these typical thermal configurations to meet requirements of the emerging advanced applications even with their maximum exploitable heat transfer performance. Specifically, those applications generating high heat fluxes such as thermal management in space, microelectronics, advanced material processing, and nuclear fusion reactors require most efficient heat transfer techniques to overcome the existing limits.
In the present study, a thermal configuration with both sides manipulated simultaneously by the phase-change heat transfer processes of internal flow boiling and external condensation is proposed and investigated analytically and experimentally. For comparison purposes, overall heat transfer performance of the proposed configuration is compared with that of a typical thermal configuration with an internal liquid single-phase flow while being exposed to the same external condensation process with the same geometrical aspects of the test section as those of the proposed configuration. Both analytical and experimental investigations revealed that the proposed thermal configuration can substantially enhance the heat transfer performance, and also set the stage for more uniform system temperature and improved system tuning compared to the other configuration due to its significant increase in overall heat transfer coefficients caused by phase-change heat transfer processes occurring at constant temperatures for both hot- and cold-side fluids. For a range of vapor qualities and mass fluxes in the laminar regime, a range of enhancement ratios of 2.5 – 3.2 was experimentally achieved, which indicates a range of improvements in heat transfer performance from 150% to 220%. The proposed thermal configuration therefore contributes effectively to the deployment of sustainable energy systems. Lastly, an experimental methodology was first introduced in the present study to estimate heat losses and calibrate the latent heat supplies for more accurate measurements of local vapor qualities in the internal flow boiling experiments
Disability theory and the dynamic of societal rejection in Mary Shelley’s Frankenstein
No full textDisability theory provided the lens by which Mary Shelley’s Frankenstein (1818) cloaked an acute commentary of dimensions within the social body. Projections onto the Creature revealed its limited critical self-awareness, and how the society Shelley set up viewed such a Creature. The Creature was rejected by society based on his appearance, thus, why he was judged so harshly could be traced back to society’s general concept of the human person. Analysis of the Creature’s rejections served to show the components at hand, such as an inability to be self-aware, and the Creature’s negative identity became an important result of this inability, along with what transformed him into the monster he became. He was primarily questioned because he appeared different on the outside, but he should not have been reduced to his physicality; hence, the relationship between society and the Creature exposed a deep anxiety of disability within the societal realm
The effect of simulated medium salt stress on seed germination, growth and development of Sorghum
No full textSorghum (Sorghum bicolor) is well known for its strong resistance to abiotic stress and wide adaptability to varying soil conditions including salt tolerance. Agricultural crops are usually not grown in soils with any measurable salt content, but irrigation and evaporation leave significant levels of salt in the soil. Elevated levels of salt generally reduce growth and yield of crops by limiting their ability to absorb water. Also, salt content affects seed germination and early establishment of crops. While seed germination and seedling establishment are important positive attributes of growth, development and yield, salt content can lead to a reduction in crop yield especially if the crop is salt sensitive. A study of simulated medium salt stress was conducted to understand the effects of salt stress on seed germination, growth and development of sorghum. Salt solution with electrical conductivities in the range of 0.01–0.30% (0.2- 6 dSm-1) conducted in two trials based on the electrical conductivities was used in a randomized complete block study. Results indicate that seed germination and chlorophyll content are statistically significant with increase in electrical conductivities for both Trial 1 and Trial 2 (P<0.0001). Also, dry shoot biomass and relative plant height of Trial 1 had a significant difference (P<0.0001) with increased electrical conductivity. The result of dry shoot biomass and relative plant height of Trial 2 were not significant
Neutralization of snake venom by a novel polyclocal antibody
No full textEnvenomation by the snake family Viperidae is characterized by hemorrhage, local necrosis, edema, and systemic effects such as coagulopathy, nephrotoxicity, neurotoxicity, and cardiotoxicity. Snake venom metalloproteases (SVMPs) and disintegrins are the critical factors responsible for hemorrhage and interfere with the hemostasis pathway. Metalloproteases from snake venoms are classified into three major classes (P-I to P-III) based on their structural domains. The disintegrin domain is a part of the P-II and P-III SVMPs, which have been reported to possess more diverse biological activities than the P-I class of SVMPs. The goal of this project is to determine the neutralization ability of anti-disintegrin polyclonal antibodies on the activities of snake venom disintegrins and P-II and P-III SVMPs. Reverse-Phase C18 High-Performance Liquid Chromatography (HPLC) was used to purify and isolate disintegrins from crude venoms. Cation Exchange HPLC was used to purify an isolate SVMPs and native disintegrins from crude snake venom. The native disintegrins were able to inhibit the migration of the cell line, SK-Mel- 28, in the “wound healing” assay, and the polyclonal antibody, anti-disintegrin inhibited these same disintegrins. The anti-disintegrin polyclonal antibody inhibited the antiplatelet activity of a recombinant disintegrin using a Sonoclot analyzer. Most importantly, anti-disintegrin was also able to inhibit the activity of SVMPs in the gelatinase and hemorrhagic assays. These anti- disintegrin disintegrin polyclonal antibodies have the potential to lay the foundation for an entirely new approach to the treatment of venomous snakebites alleviating enormous suffering worldwide. The use of antibodies can open new avenues not only for treating envenomations but also in identifying novel cellular targets of venom toxins providing the foundation for designing innovative therapeutics as well as diagnostic tools for treatment of various illnesses