A Computational Study of the Potential for LNG Tanker Polystyrene Foam Insulation Failure under Fire Exposure

Liquefied natural gas is shipped across the oceans in large marine carriers. The carriers house the LNG using several different insulation systems. One of these systems involves large aluminum spheres insulated with polystyrene foam. Polystyrene foam is very susceptible to heat degradation. This raised issues as to the extent of possible insulation failure caused by a large ship fire. Experiments were done investigating the nature of polystyrene’s thermal degradation, notably by Brauman, Chen, and Matzinger and Butler. A large scale investigation was also performed by Sandia National Laboratory. However, computational modeling of the degradation was lacking. This work set out to build comprehensive models of the experiments performed by BCM, Butler, and Sandia. The models were created using COMSOL Multiphysics, a complex finite element method computational software. The thermal degradation of polystyrene is a complex process involving moving boundaries, phase transitions, and temperature dependent physical properties. The BCM and Butler experiments provided the most amount of detail and were used to test the accuracy of the models and methods used within them. The value of principal interest was the overall regression rate of the material, a variable that could be calculated by the models and compared directly with experimentally measured values. Modeling started with an extensive literature review of the physical properties of dense and foam polystyrene. The BCM experiments were first considered as they were the least complex. Both a transient and a steady-state model of the BCM experiments were built. Although detail of the transient heat up phase was lost, the steady-state model provided a better fit with experiment. With a good fit of the BCM experiments, the techniques were carried forward and adapted to the more complex Butler foam polystyrene experiments. Again, regression rates for the model were reasonably close to those measured by experiment. Next, the Sandia experiment was investigated. Here, the values of interest were no longer regression rates but insulation failure times and cargo tank heat fluxes. The Sandia experiment presented a new complication in the form of necessary information not being available, notably the surface emissivity of the aluminum scrim used. With the model, it was found that a very low surface emissivity, one near the lowest commercially available, was required to match the experimental results

Internal Marketing in Intercollegiate Athletic Departments: Maximizing Effectiveness across Job Types

Theoretically, the results of the current study will contribute to a refined understanding of how internal marketing practices should be geared to different types of employees to maximize outcomes. In practice, the results can be used to segments internal audiences to better meet employee\u27s needs through internal marketing programs

Fabrication and characterization of locally resonant acoustic metamaterials made with resonators generated from core-shell drops

Acoustic metamaterials promise the remarkable ability to control, direct, and manipulate sound waves. Within this infant field, a promising approach to fabricate locally resonant acoustic metamaterials is the use of resonators composed of a heavy core surrounded by a rubber shell dispersed in an epoxy matrix. At the resonant frequency, the resonators vibrate 180° out-of-phase with the matrix and a band gap in transmission is observed making these materials excellent sound absorbers. The resonant frequency of the resonators scales with the core mass; therefore, it can be tailored by increasing the core diameter or the density of the core material. A significant challenge in the study and adoption of these materials is the lack of techniques to easily fabricate resonators with a wide range of sizes, and properties. Here, we present a robust yet simple technique to fabricate resonators with diameters ranging from 50 µm to 5 mm from core-shell drops generated in microfluidic and millifluidic devices. We started by fabricating resonators with core diameters ranging from 50 µm to 1 mm at rates ranging from 2000 to 200 drops/second respectively, from double emulsion drops composed of a concentrated ceramic suspension in the core (inner drop) surrounded by a UV-crosslinkable rubber shell (outer drop) using microcapillary microfluidic devices. The double emulsion drops were collected and exposed to UV to crosslink the shell material forming resonators with resonant frequencies ranging from 100 kHz to 25 kHz depending on their size. Lower resonant frequencies down to 6 kHz were obtained by fabricating resonators with core diameters ranging from 1.2 mm to 2 mm from core-shell drops extruded in air from a coaxial nozzle at rates up to 6 drops/minute. The effects of core density were studied by utilizing suspensions composed of ceramic particles of increasing density including silica, alumina, and lead zirconate titanate (PZT). Resonators were harvested, dried and mixed with epoxy to fabricate acoustic metamaterials. The transmission properties of the acoustic metamaterials made with resonators with different core diameters, core materials, and ordering within the matrix, were measured using a shaker/accelerometer setup in the frequency range from 1 kHz to 12 kHz. For example, acoustic metamaterials composed of randomly dispersed 1.8 mm alumina-core resonators at a 30 vol% concentration showed a well defined band-gap at 8.5 kHz. A finite element model was also developed to capture the acoustic transmission physics of these materials. This technique offers a robust path for the fabrication of acoustic resonators and locally resonant acoustic metamaterials

Fracture Growth Testing of Titanium 6AL-4V in AF-M315E

The Green Propellant Infusion Mission (GPIM) will demonstrate the performance of AF-M315E monopropellant in orbit. Flight certification requires a safe-life analysis of the titanium alloy fuel tank to ensure inherent flaws will not cause failure during the design life. Material property inputs for this analysis require testing to determine the stress intensity factor for environmentally-assisted cracking (K (sub EAC)) of Ti 6Al-4V in combination with the AF-M315E monopropellant. Testing of single-edge notched specimens SE(B) representing the bulk tank membrane and weld material were performed in accordance with ASTM E1681. Specimens with fatigue pre-cracks were loaded into test fixtures so that the crack tips were exposed to the monopropellant at 50 degrees Centigrade for a duration of 1,000 hours. Specimens that did not fail during exposure were opened to inspect the crack surfaces for evidence of crack growth. The threshold stress intensity value, KEAC, is the highest applied stress intensity that produced neither a failure of the specimen during the exposure nor showed evidence of crack growth. The threshold stress intensity factor of the Ti 6Al-4V forged tank material when exposed to AF-M315E monopropellant was found to be at least 22.0 kilopounds per square inch. The stress intensity factor of the weld material was at least 31.3 kilopounds per square inch

Internal Marketing Perceptions in Intercollegiate Athletics and Their Influence on Organizational Commitment

While scholars have previously focused on the external impact of marketing efforts in college athletics (e.g., Gladden, Irwin, & Sutton, 2001), little research has been done on the internal marketing orientation of collegiate sport properties and its respective impact on college sport. The purpose of this study is to determine the perceptions of internal marketing in college athletics and to examine if those perceptions have an effect on the level of organizational commitment among departmental employees. Survey methodology collected information from 248 athletic department administrators at NCAA FBS and FCS institutions. Results indicate that internal marketing orientation strongly influenced affective commitment to the organization. Further, internal marketing was found to fully mediate the relationship of job function and affective commitment. Finally, theorized moderators of job type, level of competition and gender were not statistically significant. The results support the assertion that an internal marketing orientation can be effectively implemented to foster the development of affective commitment to the organization

Mejoramiento en el proceso de originación de créditos en el Banco Financiero del Perú

Universidad Nacional Agraria La Molina. Facultad de Economía y Planificación. Departamento Académico de Gestión EmpresarialEl siguiente trabajo se realizó con el objetivo de proponer mejoras en el proceso de originación de créditos (tarjetas de crédito y préstamos personales) en el Banco Financiero del Perú. Se utilizó la metodología BPM (Business Process Management) para redefinir y diseñar el nuevo modelo de originación de créditos. Como paso inicial, se realizó la revisión del flujo actual, desde que llega un cliente a la oficina hasta el desembolso del crédito, encontrándose diversos puntos críticos por mejorar como: tiempos de atención (encontrándose mayor incidencia en la Red Retail “Carsa”), evaluación crediticia, control de expedientes, validación de información, entre otros. Los cuales generan pérdidas económicas, incrementan el nivel de riesgo y ocasionan molestias a los clientes que solicitan un producto crediticio. Posteriormente, se reestructuró el flujo de aprobación de créditos y se redefinió las funciones de las áreas que intervienen en dicho flujo. Finalmente, se implementó un nuevo Workflow conectado a un motor de decisiones el cual reemplazaría al existente. Se obtuvieron ahorros importantes para la institución, calidad de cartera, competitividad, disminución de fallas humanas y optimización de los procesos relacionados con la originación de créditos.Trabajo de suficiencia profesiona

Discrete-Event Simulation of the Establishment of a Bare Beachhead for Long-Term Joint Logistics over the Shore (JLOTS) Operations

The United States military uses Joint Logistics Over-the-Shore (JLOTS) operations to move soldiers, vehicles, and equipment across the globe for military and humanitarian missions. These logistics operations can only be accomplished through cooperation between commanders in all services.  The U.S. Army Engineer Research and Development Center is developing a tool to analyze a set of early entry alternatives to optimize mission effectives and efficiencies in order to facilitate assured mobility and freedom of movement. This program is currently being developed under the name Planning Logistics Analysis Network System (PLANS). PLANS comprehensively covers air, land, and sea transportation infrastructure, regions of avoidance, and more. This research addresses a gap in strategic and operational planning by modeling the establishment of JLOTS operations on bare beach environments. The West Point developed discrete event simulation will determine the amount of time it takes to prepare a beach to sustain JLOTS operations under varying environmental and operational conditions

Schools and Terrorism: Global Trends, Impacts, and Lessons for Resilience

This study characterizes trends in the frequency and characteristics of terrorist attacks in child-serving educational institutions around the world, examining the specific vulnerabilies of children and schools with regard to terrorist violence, as well as the various impacts that violence has on children, communities, and societies. Following the analysis of available data on terrorist attacks against educational institutions, vulnerabilities, and impacts, the study concludes with a discussion of what still needs to be understood in the intersection of child vulnerability and terrorism, and provides recommendations for improving resilience to terrorist attacks against child-serving educational institutions. One would like to think that certain truths or values would be universally understood as rules of engagement, formally declared or otherwise. The sanctity of children's well-being should be unquestioned, regardless of the issues at stake in the larger conflict. Sadly, history shows that this understanding is neither universally shared nor uniformly valued. —Irwin Redlener, Americans at Risk, 2007 Since the violent attack on School Number One in Beslan, Russia in 2004, the perceived threat of massive terror attacks targeting schoolchildren has loomed in the public consciousness. In recent years, attacks against educational institutions worldwide have increasingly been reported and documented. The kidnapping of 276 schoolgirls by Boko Haram in Nigeria and the massacre of at least 150 students and staff in a Peshawar school by the Pakistani Taliban in 2014 are still fresh in the minds of the public. These attacks serve as reminders of the vulnerability that children in schools face, being “soft targets” whose symbolic value has the capacity of invoking mayhem at the largest possible scale. They also demonstrate the urgency with which this emerging trend in violence must be systemically recorded, analyzed, and mitigated. The following article will discuss the vulnerability of children with regard to terrorist violence, exploring the literature on what makes children and educational institutions particularly desirable targets. Trends in the frequency and characteristics of terrorist attacks against child-serving educational institutions around the world will be examined, paying particular attention to potential school level and gendered disparities. Finally, a critical analysis on what can be learned from the available data and what still needs to be researched in the nexus of child vulnerability and terrorism will be provided

Acts of terrorism and mass violence targeting schools : Analysis and implications for preparedness in the USA

To enhance the preparedness of US schools to acts of terrorism and mass violence, the landscape of threats against schools must first be understood. This includes exploring the global trends of acts of terrorism against schools, as well as looking specifically at the history of terrorism and acts of mass violence against schools domestically. This paper conducts a review of two databases in order to look at the trends in acts of terrorism and mass violence carried out against schools, and provides recommendations for domestic school preparedness based on this information