5,851 research outputs found
Analyzing the United States Department of Transportation’s implementation strategy for high speed rail: Three case studies
High-speed rail (HSR) has become a major contributor to the transportation sector with a strong push by the Obama Administration and the Department of Transportation to implement high-speed rail in the United States. High-speed rail is a costly transportation alternative that has the potential displace some car and airport travel while increase energy security and environmental sustainability. This thesis will examine the United States high-speed rail implementation strategy by comparing it to the implementation strategies of France, Japan, and Germany in a multiple case study under four main criteria of success: economic profitability, reliability, safety, and ridership. Analysis will conclude with lessons to be taken away from the case studies and applied to the United States strategy. It is important to understand that this project has not been established to create a comprehensive implementation plan for high-speed rail in the United States; rather, this project is intended to observe the depth and quality of the current United States implementation strategy and make additional recommendations by comparing it with France, Japan, and Germany
PNNL Dark Matter Bubble Chamber
The Pacific Northwest National Laboratory (PNNL) prototype bubble chamber is intended to address issues encountered with the current PICO dark matter search detectors and improve the functionality of future experimental designs. The PNNL bubble chamber accomplishes this with a simplified interface between the hydraulic pressure controls and the target vessel and altering the standard chamber design such that it can be easily exchanged and replaced with vessels of various sizes and materials for testing purposes. The chamber itself is a glass vessel which houses perfluorobutane and holds the target fluid above room temperature and atmospheric pressure. The target fluid becomes a metastable superheated liquid that undergoes a localized phase change in areas where particles with sufficient energy interact with the fluid’s nuclei and nucleate bubbles. The temperature of the chamber is controlled by submersing the target vessel in a heated water bath to ensure the target fluid remains in a metastable superheated state. The hydraulic pressure can be adjusted to maintain energy thresholds above which gamma rays or electron (significant backgrounds to most dark matter searches) energy deposition is insufficient to cause the target fluid to undergo a phase change. The chamber itself is monitored by 200 fps cameras adapted with nucleation threshold trigger algorithms and a series of piezo-electric sensors to capture visual and acoustic information of bubble nucleation events. Once triggered, nucleated bubbles are collapsed by the opening of automatic solenoid valves contained in the hydraulic cart which causes a compression of the cold system and increases the pressure within the bubble chamber. The pressure in the hydraulic cart is then reduced, allowing for the system to expand, releasing pressure within the cold zone and the bubble chamber, and prepares the chamber for the next event. The presented work towards the commissioning of the PNNL bubble chamber includes the design and construction of the hydraulic cart, system mounting framework, compressed air and water testing, laboratory setup and organization, and solid works structure design
Holocene landform evolution and natural site formation processes at the West Blennerhassett archaeological site (46WD83-A), Wood County, West Virginia
This study utilizes sedimentary, pedological, and archaeological data recovered from the West Blennerhassett site (46WD83-A), a deeply stratified archaeological site located at Blennerhassett Island, an Ohio River island in Wood County, West Virginia, to determine a site-specific history of landform evolution and natural site formation processes. Archaeological investigations were conducted at West Blennerhassett by the Cultural Resources Section of Michael Baker Jr., Inc. in 2002 and 2003 as part of the environmental studies for the U.S. Route 50 Blennerhassett Bridge Project for the West Virginia Division of Highways and the Federal Highways Administration. These investigations revealed stratified archaeological deposits extending to a minimum of 5 m in Holocene alluvium and dating from approximately 8660 B.P.;Results of particle-size analysis, bolstered by a robust radiocarbon chronology, indicate that the West Blennerhassett site was a rapidly accreting, dynamic, near-channel environment from at least 8660 to 7010 B.P. Rapid sedimentation and high-energy floods gave way to a more quiescent setting at ca. 7010 B.P., apparently as a result of vertical accretion of the site coupled with vertical incision and, possibly, lateral migration of the Ohio River channel. Alluvial sedimentation rates remained slow and the site was dominated by a low-energy overbank flood regime until ca. 3000 B.P. A distinct discontinuity in the sedimentary stratigraphy at ca. 3000 B.P. marks a return of a relatively high-energy flood regime, presumably due to combined climatic and anthropogenic factors.;Archaeological deposits from the early Holocene, prior to 7010 B.P., were subject to high-energy Ohio River discharges; some were reworked or eroded, while others were sealed in discrete contexts. A hiatus in human occupation of the site occurred between ca. 7010 and 4315 B.P., but was followed by serial occupations throughout the late Holocene. Slow sedimentation rates have resulted in minimal vertical separation between assemblages from individual occupations in the late Holocene. As such, occupation-specific archaeological assemblages deposited after 4315 B.P. are essentially indiscernible
The Silent War: Free Speech and the Right to Information in the Context of Military Sexual Assault
Project Extranets : b a strategic necessity or a tool for competitive advantage?
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2000.Vitae.Includes bibliographical references (leaves 78-80).An exploratory study was conducted to determine the strategic advantage that firms may gain by using project extranets on real estate development projects. Eight organizations were interviewed to determine their priorities, risk preferences, and needs regarding project communication technologies. Interviews were conducted with Corporate Owner/Occupiers, Owner/Non Occupiers, and Institutional Owner/Occupiers. The hypothesis tested was that owners and developers of real estate were looking to use project extranets to gain a competitive advantage. Research results indicated a resounding 'no' to our hypothesis. No owners or developers are currently looking at extranets as a source of competitive advantage at this time. However, the research data did provide insights into what is necessary for the technology to deliver for organizations to view a project extranet as a source of competitive advantage in the future. Owners were segmented into categories based on risk profile and needs regarding project extranets. Corporate Owner/Occupiers with real estate support needed assistance with predictability and execution. Corporate Owner/Occupiers of Manufacturing operations needed increases in speed. Institutional Owner/Occupiers needed certainty. Finally Owner/Non-Occupiers needed mitigation of market risks.by Ryan Carley [and] Matthew Robinson.S.M
How possible was Prometheus’ punishment?
In this paper we discuss the feasibility of the regeneration of Prometheus’ liver – would cells be able to regrow fast enough to allow Prometheus’ liver to be eaten every day by an eagle?  For this, a simple model is constructed that incorporates the eating habits of eagles – how much food they eat in a day – as well as the natural regeneration time of a human liver. Our calculations have shown that if Prometheus’ liver was the only food source of the eagle (300 g consumed per day), it would take approximately 2 days for complete regeneration of the mass of Prometheus’ liver, but that 160.5 g of the liver could be eaten each day by the eagle and still result in complete regeneration
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Integration of Direct-Write (DW) and Ultrasonic Consolidation (UC) Technologies to Create Advanced Structures with Embedded Electrical Circuitry
In many instances conductive traces are needed in small, compact and enclosed areas.
However, with traditional manufacturing techniques, embedded electrical traces or antenna
arrays have not been a possibility. By integrating Direct Write and Ultrasonic Consolidation
technologies, electronic circuitry, antennas and other devices can be manufactured directly into a
solid metal structure and subsequently completely enclosed. This can achieve a significant
reduction in mass and volume of a complex electronic system without compromising
performance.Mechanical Engineerin
The epidemiology of noncommunicable respiratory disease in sub-Saharan Africa, the Middle East, and North Africa
Noncommunicable diseases (NCDs) are a major and increasing global health issue. The World Health Organization (WHO) estimates that NCDs represent 63% of all global deaths of which 3.9 million are due to chronic respiratory diseases (CRDs) and Chronic Obstructive Pulmonary Disease (COPD) in particular. COPD is now the third most common cause of death globally; 90% of these deaths occur in Low and Middle Income Countries (LMICs). COPD affects 329 million people, almost 5% of the world's population. In addition, asthma affects 334 million people, again representing almost 5% of the world's population. There is limited literature published on the epidemiology of COPD and Asthma from Sub-Saharan Africa (SSA) and Middle East and North Africa (MENA). Both diseases are under-diagnosed and underestimated in both SSA and MENA regions. The burden of COPD in sub-Saharan Africa is disputed and reports offer variable prevalence estimates, ranging from 4.1% to almost 22.2%. SSA and MENA countries report similar mortality rates from COPD of 18 per 100,000 population (2001 data). Asthma is a less common cause of death than COPD but is a major cause of morbidity; WHO estimates that there are 250,000 deaths per year from asthma, mainly in LMICs and it remains in the top twenty causes of disability in children globally. Risk factors for CRD are genetic and environmental; the latter dominated by air pollution exposures including tobacco smoke, household air pollution, outdoor air pollution and occupational exposures
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