3,251 research outputs found
Performance of the Lester battery charger in electric vehicles
Tests are performed on an improved battery charger. The primary purpose of the testing is to develop test methodologies for battery charger evaluation. Tests are developed to characterize the charger in terms of its charge algorithm and to assess the effects of battery initial state of charge and temperature on charger and battery efficiency. Tests show this charger to be a considerable improvement in the state of the art for electric vehicle chargers
Antenna pointing compensation based on precision optical measurement techniques
The pointing control loops of the Deep Space Network 70 meter antennas extend only to the Intermediate Reference Structure (IRS). Thus, distortion of the structure forward of the IRS due to unpredictable environmental loads can result in uncompensated boresight shifts which degrade blind pointing accuracy. A system is described which can provide real time bias commands to the pointing control system to compensate for environmental effects on blind pointing performance. The bias commands are computed in real time based on optical ranging measurements of the structure from the IRS to a number of selected points on the primary and secondary reflectors
Automated Mixed Traffic Vehicle (AMTV) technology and safety study
Technology and safety related to the implementation of an Automated Mixed Traffic Vehicle (AMTV) system are discussed. System concepts and technology status were reviewed and areas where further development is needed are identified. Failure and hazard modes were also analyzed and methods for prevention were suggested. The results presented are intended as a guide for further efforts in AMTV system design and technology development for both near term and long term applications. The AMTV systems discussed include a low speed system, and a hybrid system consisting of low speed sections and high speed sections operating in a semi-guideway. The safety analysis identified hazards that may arise in a properly functioning AMTV system, as well as hardware failure modes. Safety related failure modes were emphasized. A risk assessment was performed in order to create a priority order and significant hazards and failure modes were summarized. Corrective measures were proposed for each hazard
Hybrid vehicle assessment. Phase 1: Petroleum savings analysis
The results of a comprehensive analysis of near term electric hybrid vehicles are presented, with emphasis on their potential to save significant amounts of petroleum on a national scale in the 1990s. Performance requirements and expected annual usage patterns of these vehicles are first modeled. The projected U.S. fleet composition is estimated, and conceptual hybrid vehicle designs are conceived and analyzed for petroleum use when driven in the expected annual patterns. These petroleum consumption estimates are then compared to similar estimates for projected 1990 conventional vehicles having the same performance and driven in the same patterns. Results are presented in the form of three utility functions and comparisons of sevral conceptual designs are made. The Hybrid Vehicle (HV) design and assessment techniques are discussed and a general method is explained for selecting the optimum energy management strategy for any vehicle mission battery combination. Conclusions and recommendations are presented, and development recommendations are identified
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The Proposed U.S.-South Korea Free Trade Agreement (KORUS FTA): Provisions and Implications
On June 30, 2007, United States Trade Representative Susan Schwab and South Korean Foreign Trade Minister Kim Hyung-chong signed the proposed U.S.-South Korean Free Trade Agreement (KORUS FTA) for their respective countries. If approved, the KORUS FTA would be the largest FTA that South Korea has signed to date and would be the second largest (next to North American Free Trade Agreement NAFTA) in which the United States participates. South Korea is the seventh-largest trading partner of the United States and the United States is South Korea’s third largest trading partner. Various studies conclude that the agreement would increase bilateral trade and investment flows.
The final text of the proposed KORUS FTA covers a wide range of trade and investment issues and, therefore, could have wide economic implications for both the United States and South Korea. The KORUS FTA includes issues on which the two countries achieved early agreement, such as the elimination on tariffs on trade in most manufactured goods and the partial liberalization in services trade. The agreement also includes provisions on a number of very sensitive issues, such as autos, agriculture, and trade remedies, on which agreement was reached only during the final hours of negotiations.
If the agreement is to enter into force, Congress will have to approve implementation legislation. The negotiations were conducted under the trade promotion authority (TPA), also called fast-track trade authority, that the Congress granted the President under the Bipartisan Trade Promotion Act of 2002 (P.L. 107-210). The authority allows the President to enter into trade agreements that receive expedited congressional consideration (no amendments and limited debate). The White House has not indicated when it will send the draft implementing legislation to Congress. (The TPA sets no deadline for the President to do this.)
While a broad swath of the U.S. business community supports the agreement, the KORUS FTA faces opposition from some groups, including some auto and steel manufacturers and labor unions. In addition, the agricultural community and some Members of Congress have withheld support for the agreement until South Korea lifts its restrictions on imports of U.S. beef. Some U.S. supporters view passage of the KORUS FTA as important to secure new opportunities in the South Korea market. Opponents claim that the KORUS FTA does not go far enough in opening up the South Korean market and is a lost opportunity to resolve long running concerns about South Korean barriers. Other observers have suggested the outcome of the KORUS FTA could have implications for the U.S.-South Korean alliance as a whole.
Differences between the White House and the Democratic leadership in the Congress over the implications of the KORUS FTA have made the timing and even the likelihood of the President’s submission and the Congress’s subsequent consideration of implementing legislation uncertain. This report will be updated as events warrant
Flexible structure control laboratory development and technology demonstration
An experimental structure is described which was constructed to demonstrate and validate recent emerging technologies in the active control and identification of large flexible space structures. The configuration consists of a large, 20 foot diameter antenna-like flexible structure in the horizontal plane with a gimballed central hub, a flexible feed-boom assembly hanging from the hub, and 12 flexible ribs radiating outward. Fourteen electrodynamic force actuators mounted to the hub and to the individual ribs provide the means to excite the structure and exert control forces. Thirty permanently mounted sensors, including optical encoders and analog induction devices provide measurements of structural response at widely distributed points. An experimental remote optical sensor provides sixteen additional sensing channels. A computer samples the sensors, computes the control updates and sends commands to the actuators in real time, while simultaneously displaying selected outputs on a graphics terminal and saving them in memory. Several control experiments were conducted thus far and are documented. These include implementation of distributed parameter system control, model reference adaptive control, and static shape control. These experiments have demonstrated the successful implementation of state-of-the-art control approaches using actual hardware
Evidence of animal mtDNA recombination between divergent populations of the potato cyst nematode Globodera pallida
Recombination is typically assumed to be absent in animal mitochondrial genomes (mtDNA). However, the maternal mode of inheritance means that recombinant products are indistinguishable from their progenitor molecules. The majority of studies of mtDNA recombination assess past recombination events, where patterns of recombination are inferred by comparing the mtDNA of different individuals. Few studies assess contemporary mtDNA recombination, where recombinant molecules are observed as direct mosaics of known progenitor molecules. Here we use the potato cyst nematode, Globodera pallida, to investigate past and contemporary recombination. Past recombination was assessed within and between populations of G. pallida, and contemporary recombination was assessed in the progeny of experimental crosses of these populations. Breeding of genetically divergent organisms may cause paternal mtDNA leakage, resulting in heteroplasmy and facilitating the detection of recombination. To assess contemporary recombination we looked for evidence of recombination between the mtDNA of the parental populations within the mtDNA of progeny. Past recombination was detected between a South American population and several UK populations of G. pallida, as well as between two South American populations. This suggests that these populations may have interbred, paternal mtDNA leakage occurred, and the mtDNA of these populations subsequently recombined. This evidence challenges two dogmas of animal mtDNA evolution; no recombination and maternal inheritance. No contemporary recombination between the parental populations was detected in the progeny of the experimental crosses. This supports current arguments that mtDNA recombination events are rare. More sensitive detection methods may be required to adequately assess contemporary mtDNA recombination in animals
Bioelectronic DNA detection of human papillomaviruses using eSensorâ„¢: a model system for detection of multiple pathogens
BACKGROUND: We used human papillomaviruses (HPV) as a model system to evaluate the utility of a nucleic acid, hybridization-based bioelectronic DNA detection platform (eSensorâ„¢) in identifying multiple pathogens. METHODS: Two chips were spotted with capture probes consisting of DNA oligonucleotide sequences specific for HPV types. Electrically conductive signal probes were synthesized to be complementary to a distinct region of the amplified HPV target DNA. A portion of the HPV L1 region that was amplified by using consensus primers served as target DNA. The amplified target was mixed with a cocktail of signal probes and added to a cartridge containing a DNA chip to allow for hybridization with complementary capture probes. RESULTS: Two bioelectric chips were designed and successfully detected 86% of the HPV types contained in clinical samples. CONCLUSIONS: This model system demonstrates the potential of the eSensor platform for rapid and integrated detection of multiple pathogens
Changes in gene expression following trauma are related to the age of transfused packed red blood cells
BACKGROUND
Transfusion of packed red blood cells (PRBCs) is associated with an increased incidence of nosocomial infections and an increased risk of death. The duration of storage before transfusion may influence these outcomes. Here, we explore the association between the age of transfused PRBCs and specific patterns of inflammatory gene expression in severely injured trauma patients.
METHODS
Severely injured trauma patients requiring intensive care unit treatment and receiving transfusion of PRBCs within 24 hours of the injury were recruited. Blood samples were obtained within 2 hours of the trauma, at 24 hours, and at 72 hours. Messenger RNA was extracted from whole blood, and gene expression was quantified using quantitative polymerase chain reaction. The median age of the units of PRBCs transfused to each patient was recorded. The primary outcome measure was the change in candidate gene expression over the initial 72 hours.
RESULTS
Sixty-four patients were studied. Fifty-three patients (83%) were male, and the median age was 40.5 years (interquartile range [IQR], 31-59). Median Injury Severity Score (ISS) was 31.5 (IQR, 23-43), and 55 patients (86%) experienced a blunt injury. Forty-one patients (64%) developed a nosocomial infection, and 15 patients (23%) died before hospital discharge. Each patient received a median of 5 U of PRBCs (IQR, 4-9.8 U) during the first 24 hours of hospital admission. The median age of the units of PRBCs transfused in each patient was 20 days (IQR, 17-22 days). Older blood was associated with greater decreases in interleukin 12 (IL-12), IL-23, and RORγt (all p's < 0.05) gene expression over the initial 24 hours, greater decreases in IL-12 gene expression over 72 hours, and a rise in transforming growth factor β gene expression over the first 72 hours. A multivariate analysis confirmed the independence of these associations.
CONCLUSION
Increasing the duration of storage of PRBCs before transfusion is associated with a pattern of gene expression consistent with more severe immunosuppression.
LEVEL OF EVIDENCE
Epidemiologic study, level III
Psychologizing indexes of societal progress: Accounting for cultural diversity in preferred developmental pathways
Since the Second World War, the dominating paradigm of societal development has focused on economic growth. While economic growth has improved the quality of human life in a variety of ways, we posit that the identification of economic growth as the primary societal goal is culture-blind because preferences for developmental pathways likely vary between societies. We argue that the cultural diversity of developmental goals and the pathways leading to these goals could be reflected in a culturally sensitive approach to assessing societal development. For the vast majority of post-materialistic societies, it is an urgent necessity to prepare culturally sensitive compasses on how to develop next, and to start conceptualizing growth in a more nuanced and culturally responsive way. Furthermore, we propose that cultural sensitivity in measuring societal growth could also be applied to existing development indicators (e.g. the Human Development Index). We call for cultural researchers, in cooperation with development economists and other social scientists, to prepare a new cultural map of developmental goals, and to create and adapt development indexes that are more culturally sensitive. This innovation could ultimately help social planners understand the diverse pathways of development and assess the degree to which societies are progressing in a self-determined and indigenously valued manner.info:eu-repo/semantics/acceptedVersio
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