4,672 research outputs found
The Little Engine that Could : Development of an Electromechanical Valvetrain
The goal of the present project is to design and implement an electromechanical valvetrain for a single-cylinder gasoline engine. This system is to replace the existing fully mechanical camshaft-based valvetrain with a computer-controlled system capable of independently controlling each engine valve. This system can improve the power and fuel efficiency of the engine by removing the inefficiencies caused by the camshaft-based valvetrain. Recently, the Camcon and FreeValve companies have each developed similar systems which replace the camshaft in automobile engines and provide up to 15% increases in fuel economy. The electromechanical valvetrain of this project uses high-speed electric air valves to control the flow of air to high-speed pneumatic rams which open and close the engine valves. A primary improvement of this system is the expected ability to open the engine valves faster than a camshaft-based valvetrain. The pneumatic-based design was chosen for its cost effectiveness, manufacturability and availability of suitable components to simplify production of a working system
Lashkar-I-Taiba: The Fallacy of Subservient Proxies and the Future of Islamist Terrorism in India
A discussion of the foundation of Lashkar-i-Taiba (LeT), the development of its modus operandi, and engages in an investigation of LeT’s activities in India, Pakistan, and the Kashmir region are discussed. Further, LeT’s fundraising methods are touched upon, and LeT’s relationships with regional state and nonstate actors such as Pakistan’s Inter-Services Intelligence (ISI) and Dawood Ibrahim’s D-Company are analyzed. Also, the impact that these developments have on domestic Islamist terrorism in India are addressed. The author argues that although LeT has been a vital component of Islamabad’s regional strategy in the past, the organization has grown beyond the control of its former patron, is largely self-sufficient and operates independently of the political process, and has expanded its agenda well beyond Kashmir. These developments challenge the long-held notion that irregulars can be sustainably used to achieve limited objectives in an asymmetric conflict and should serve as a clear warning to other state sponsors of terrorism. However, contrary to many analyses, LeT is not likely to sacrifice its independence and come under Al-Qaeda’s umbrella. Rather, LeT will continue to evolve into a distinctive, South Asia-centric terrorist actor in its own right while still receiving aid from fringe elements in Pakistan’s security and intelligence apparatus and elsewhere. This will not only allow LeT to continue to plan future Mumbai-style terrorist attacks in India from safe havens in Pakistan, but will also allow LeT to guide and assist the predominantly indigenous Indian Mujahideen (IM).https://press.armywarcollege.edu/monographs/1347/thumbnail.jp
Chinese Energy Security: The Myth of the PLAN\u27s Frontline Status
This monograph examines the dynamics of China’s energy security dilemma and the role of the People’s Liberation Army Navy (PLAN). Following this, PLAN development is discussed and its future role in regional security is hypothesized. This report argues that it is domestic market inefficiencies and poor management practices that pose the greatest threat to China’s energy security. Further, less and less of Chinese energy imports are making their way to the country by sea, and as such, the PLAN actually has a minimal role to play. Given these realities, Chinese fears of a naval blockade that deprives it of energy supplies, and American confidence that this is a realistic strategic option in the event of hostilities are implausible. In addition, Beijing’s desire to develop aircraft carriers and other high-tech naval capabilities, combined with its contribution to the anti-piracy mission in the Gulf of Aden, have led many analysts to erroneously conclude that China seeks to engage in global power projection like the United States. However, the focus of the PLAN will remain regional and on asymmetric capabilities, namely the effective use of submarines and other undersea “unknowns” that ultimately seek to deter American and possible Japanese involvement in a conflict over Taiwan and/or maritime features in the South China Sea, such as the Spratly Islands, which China views as inalienable parts of its territory. Although China’s interests are expanding and becoming more international in nature, recovering from the Century of Humiliation and ensuring domestic legitimacy remain the top priorities of China’s leadership.https://press.armywarcollege.edu/monographs/1344/thumbnail.jp
Vertical Sediment Accretion in Jamaica Bay Wetlands, New York
Over the last century, ~60% of the saltmarsh wetlands in Jamaica Bay (in the Gateway National Recreation Area of the Greater New York City region) have been converted to intertidal or subtidal unvegetated mudflats and projections suggest that all of Jamaica Bay’s saltmarsh wetlands may disappear within the next two decades. After landfall of Hurricane Sandy in 2012 and to better understand environmental controls on the maintenance of the remaining Jamaica Bay wetlands, cores were collected from twelve saltmarsh locations in the bay to study the chronology of wetland vertical accretion and mineral sediment accumulation. In association with the United States Geological Survey Wetland and Aquatic Research Center (formerly National Wetlands Research Center), cores were analyzed for 137Cs /210Pb geochronology, percent mineral content, and total water content. Results show that averaged sediment accumulation rates for the wetlands are 0.48 cm-yr-1. Analysis of sediment core mineral content indicates the uneven presence of a mineral-rich surface layer that is likely the result of sediment delivery from Hurricane Sandy. Results also document the presence of numerous subsurface layers of mineral-rich sediment interbedded between zones of organic-rich sediment. Based on various radionuclide chronologies, the estimated time of deposition, mineral-rich layers correspond to the known landfalls of major hurricanes near Jamaica Bay over the last nine decades. Collectively, these results suggest that sediments are delivered unevenly by landfalling hurricanes to coastal wetlands and that other phenomena that flood coastal wetlands with suspended sediments, such as extra-tropical storms, are important sediment sources as well
Assessment of Pain in adults with cognitive impairment : a review of the tools
The aim of this paper is to discuss the results of a review into the literature related to chronic pain and the older adult. Several themes within the review have been identified and reported elsewhere and the final report has been published by the University of Sheffield in the form of an annotated bibliography. This report focuses upon the findings of the in relation to the assessment of pain in the adult with cognitive impairment. Issues surrounding assessment in the non-cognitively impaired older adult have also been reported elsewhere. For this paper nine studies will be discussed which report the development and testing of pain assessment scales the focus of which is upon behavioural indicators of pain. Some scales have been omitted from the review and the rationale for this decision will be discussed. Each of the selected scales will be discussed and the authors will make recommendations for both clinical practice and for future research based upon the validity, reliability and user friendliness of the scales. From the paper it can be concluded that the Abbey, DOLOPLUS-2 and PACSLAC appear to be the most reliable and valid and in terms of the “user friendliness” would be appropriate to explore further. Recommendations are made for further multi-centre evaluation of these scales.University of Sheffiel
Assessment of pain in older people : where are we now and what needs to be done?
The purpose of this paper is to present the findings of a review of the literature into pain and older people. The funded study was part of the development of an annotated bibliography published in August 2005. The review included all major databases and involved the collection of 214 papers between the dates of 1995 and 2005. The papers were divided into several major themes, which include experiences, management (pharmacological and non-pharmacological), assessment, and attitudes. Within this paper, the results of the review into pain assessment will be discussed, which includes 42 of the collected papers. The other sections will be published later. The paper will discuss issues pertaining to the development of specific tools for older people, a discussion of tools already available, comparisons of staff versus older people’s perceptions of pain scales, and articles with cognitive impairment as a focus. Recommendations for further study are made.University of Sheffiel
Tuning Electronic Structure To Control Manganese Nitride Activation
Investigation of a series of oxidized nitridomanganese(V) salen complexes with different para ring substituents (R = CF3, tBu, and NMe2) demonstrates that nitride activation is dictated by remote ligand electronics. For R = CF3 and tBu, oxidation affords a Mn(VI) species and nitride activation, with dinitrogen homocoupling accelerated by the more electron-withdrawing CF3 substituent. Employing an electron-donating substituent (R = NMe2) results in a localized ligand radical species that is resistant to N coupling of the nitrides and is stable in solution at both 195 and 298 K
Investigación acción para el desarrollo profesional y curricular en la enseñanza de las Ciencias en la escuela infantil
Development of an Electromechanical Valvetrain
The Electromechanical Valvetrain Conversion Team designed and implemented a new system to improve internal combustion engine performance and efficiency. This system replaces the traditional camshaft-based valvetrain with a computer-controlled pneumatic actuation system. This new system has the potential to reduce emissions without sacrificing the benefits which have made combustion engines a popular power source.https://pilotscholars.up.edu/egr_project/1026/thumbnail.jp
Conversion of aldoses to valuable ω-amino alcohols using amine transaminase biocatalysts
The conversion of readily available monosaccharides to high-value amino alcohols using a key biocatalytic step is an attractive strategy for the preparation of these chiral synthons. Here, we report a previously undescribed example of the direct amination of monosaccharides, which exist predominantly in their cyclic form at equilibrium, using amine transaminase biocatalysts, providing access to a panel of amino alcohols in moderate to high conversion and isolated yield. A recently developed high-throughput colorimetric screen, employing o-xylylenediamine, was initially used to identify amine transaminase enzymes displaying this activity towards cyclic sugars and reactions were successfully scaled-up using isopropylamine
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