Suchergebnisse

High-step-up converters are widely used for solar power applications. In that, impedance source converters are mostly preferred as it has a special feature of high gain at a low-duty cycle. However, the traditional impedance source converters have limited duty ratio operation and high stress across the network and the device. Thus, this paper presents a new type of quasi-impedance source dc-dc converter. The proposed converter has a large boost ratio operation using a switch voltage spike reduction technique. This reduces the stress across the network as well as across the device. The performance of the proposed topology has been investigated against several types of quasi-impedance source converters such as a switched capacitor, inductance alone, embedded, and conventional quasi-impedance source converter. The results clearly show that the projected modified quasi-impedance source converter topology has a high efficiency of 92 %. The modes of operation and comparative study of the modified topology are presented. A 60 W laboratory setup is developed to investigate the performance of the suggested converter, and the simulation results are verified experimentally.

With a view to better assessment of the roles played by social security and social policy in determining well-being, this presentation introduces the 'decommodified security ratio' (DSR), an instrument for evaluating an important duty of the social State, namely to maintain and improve people's economic security. To that end we describe the conventions for its use and analyse its main components in 24 countries in 1999-2001, by using the wave V of Luxembourg Income Survey database. From an analysis of the sources of economic security we then distinguish five different rationales.

The article of record as published may be found at http://dx.doi:10.3928/01477447-20120621-14 ; Although greater trochanteric pain syndrome is thought to be a common musculoskeletal disorder, little has been reported on the incidence rates of the disorder. The purpose of this study was to determine the incidence and demographic risk factors of greater trochanteric pain syndrome in a United States military population. Multivariate Poisson regression analysis was used to estimate the rate of greater trochanteric pain syndrome per 1000 person-years, controlling for sex, race, age, rank, and branch of service. The overall unadjusted incidence rate of greater trochanteric pain syndrome was 2.03 per 1000 person-years. Women had a significantly increased adjusted incidence rate ratio for greater trochanteric pain syndrome of 5.03 (95% confidence interval [CI], 4.91-5.16). The adjusted incidence rate ratio for White servicemembers compared with Black servicemembers was 1.36 (95% CI, 1.32-1.40). The adjusted incidence rate ratio for the 40+ age group compared with the 25 to 29 age group was 2.81 (95% CI, 2.68-2.95). Compared with junior officers, junior and senior enlisted ranks had an increased adjusted incidence rate ratio of 1.94 (95% CI, 1.84-2.04) and 1.17 (95% CI, 1.12-1.23), respectively. Compared with the Navy, each branch of service had an increased adjusted incidence rate ratio, with the Army at 2.90 (95% CI, 2.80-3.01), the Marines at 1.96 (95% CI, 1.87-2.07), and the Air Force at 1.33 (95% CI, 1.27-1.38). Female servicemembers had a five-fold greater incidence of greater trochanteric pain syndrome. Increasing age, enlisted rank groups, and service in the Army, Marines, or Air Force were also significant risk factors.

BACK GROUND Due to the nature of their job military personnel is highly mobile and posted away from their family for extended period of time. As result personnel who are on active military service may be exposed to undesirable sexual behaviors. OBJECTIVES: The objective of this study was to assess the relationship between duty location and sexual behavior of married military personnel. METHODS: This is a comparative cross-sectional study conducted among military personnel in Tigray. Data were collected using self administered questionnaire and FGD from married military personnel RESULTS: Military personnel stationed away from their spouses were more likely to have extra-marital sex than those who were living together with their spouses, adjusted odds ratio is 2.14(1.40, 3.27) Conclusion: Military personnel posted away from their spouse are likely to be engaged in sexually risk behaviors thus appropriate sexual health package including condom promotion and regulation of commercial sex industry need to be strengthened

BACK GROUND Due to the nature of their job military personnel is highly mobile and posted away from their family for extended period of time. As result personnel who are on active military service may be exposed to undesirable sexual behaviors. OBJECTIVES: The objective of this study was to assess the relationship between duty location and sexual behavior of married military personnel. METHODS: This is a comparative cross-sectional study conducted among military personnel in Tigray. Data were collected using self administered questionnaire and FGD from married military personnel RESULTS: Military personnel stationed away from their spouses were more likely to have extra-marital sex than those who were living together with their spouses, adjusted odds ratio is 2.14(1.40, 3.27) Conclusion: Military personnel posted away from their spouse are likely to be engaged in sexually risk behaviors thus appropriate sexual health package including condom promotion and regulation of commercial sex industry need to be strengthened

Intro -- FrontMatter -- Preface -- Contents -- Boxes, Figures, and Tables -- Summary -- 1 Introduction -- 2 Technologies for Reducing Fuel Consumption in Spark-Ignition Engines -- 3 Technologies for Reducing Fuel Consumption in Compression-Ignition Diesel Engines -- 4 Electrified Powertrains -- 5 Transmissions -- 6 Non-Powertrain Technologies -- 7 Cost and Manufacturing Considerations for Meeting Fuel Economy Standards -- 8 Estimates of Technology Costs and Fuel Consumption Reduction Effectiveness -- 9 Consumer Impacts and Acceptance Issues -- 10 Overall Assessment of CAFE Program Methodology and Design -- Appendix A: Statement of Task -- Appendix B: Committee Biographies -- Appendix C: Presentations and Committee Meetings -- Appendix D: Ideal Thermodynamic Cycles for Otto, Diesel, and Atkinson Engines -- Appendix E: SI Engine Definitions and Efficiency Fundamentals -- Appendix F: Examples of Friction Reduction Opportunities for Main Engine Components -- Appendix G: Friction Reduction in Downsized Engines -- Appendix H: Variable Valve Timing Systems -- Appendix I: Variable Valve Lift Systems -- Appendix J: Reasons for Potential Differences from NHTSA Estimates for Fuel Consumption Reduction Effectiveness of Turbocharged, Downsized Engines -- Appendix K: DOE Research Projects on Turbocharged and Downsized Engines -- Appendix L: Relationship between Power and Performance -- Appendix M: HCCI Projects -- Appendix N: Effect of Compression Ratio of Brake Thermal Efficiency -- Appendix O: Variable Compression Ratio Engines -- Appendix P: Fuel Consumption Impact of Tier 3 Emission Standards -- Appendix Q: Examples of EPA's Standards for Gasoline -- Appendix R: Impact of Low Carbon Fuels to Achieve Reductions in GHG Emissions (California LCFS 2007 - Alternative Fuels and Cleaner Fossil Fuels CNG, LPG)

1. Survey of the Existing Analysis Methods -- 1. Introduction to the Injected-Absorbed-Current Method of Analysis -- 2. Elementary Converters Operating at Constant Frequency with Duty Ratio as Controlled Quantity -- 3. General Small-Signal, Low-Frequency Analysis of Switching Regulators -- 4. State-Variables-Averaging Method -- 2. Multiple-Loop Switching Power Cells -- 5. Elementary Switching Power Cells with Inductor Current as Controlled Quantity -- 6. Multiple-Loop Switching Cells Using Inductor Voltage in a Minor Feedback Loop -- 3. Special Configurations -- 7. ?uk and SEPIC Switching Cells -- 8. Analysis of Power Cells with Duty-Ratio Control at Variable Frequency -- 9. Free-Running Hysteretic Regulator -- 4. Applications of Linear Analysis Method -- 10. Interconnection of a Power Source and a Switching Regulator -- 11. Feedforward in Switching Regulators -- 12. Parallel Operation of Switching Regulators -- 5. Selected Analytic Approaches and Applications and Future Advances in Analysis Methods -- 13. Selected Analysis Examples -- 14. High-Frequency Extension of the Linear Cell Model -- Appendixes -- Appendix 1. Additional Information for Chapter 5 -- A1-1 Derivation of Time Delay Between Control and Injected Current for Constant Off Time Current-Mode Control -- A1-2 Control-to-Output Voltage Functions of CurrentMode-Controlled Buck Converter with Three Different Control Methods -- Appendix 2. Graphical-Analytical Representation of Transfer Functions -- A2-1 Introduction -- A2-2 Transfer Functions of Passive Networks -- References -- Appendix 3. Examples and Problems -- A3-1 Introduction -- A3-2 Appendix to Chapter 2—Regulators Employing Elementary Cells, Operating at Constant Switching Frequency, and with Duty Ratio as the Controlled Quantity -- A3-3 Appendix to Chapter 14—Successive Approximations of the Cell Controlled-Quantity-to-Output-Voltage Transfer Function -- Appendix 4. Sources of Technical Information -- A4-1 Conferences -- A4-2 Periodicals -- A4-3 Compendia -- A4-4 Textbooks.

Runners were classified using two different methods based on their spontaneous running form: (1) subjectively using the V®score from the Volodalen® scale, leading to terrestrial and aerial groups; and (2) objectively using the duty factor (DF), leading to high (DFhigh) and low (DFlow) DF groups. This study aimed to compare these two classification schemes. Eighty-nine runners were divided in two groups using the V®score (VOL groups) and were also ranked according to their DF. They ran on a treadmill at 12 km·h−1 with simultaneous recording of running kinematics, using a three-dimensional motion capture system. DF was computed from data as the ratio of ground contact time to stride time. The agreement (95% confidence interval) between VOL and DF groups was 79.8% (69.9%, 87.6%), with relatively high sensitivity (81.6% (68.0%, 91.2%)) and specificity (77.5% (61.6%, 89.2%)). Our results suggest that the DF and V®score reflect similar constructs and lead to similar subgroupings of spontaneous running form (aerial runners if DF < 27.6% and terrestrial runners if DF > 28.8% at 12 km·h−1). These results suggest that DF could be a useful objective measure to monitor real-time changes in spontaneous running form using wearable technology. As a forward-looking statement, spontaneous changes in running form during racing or training could assist in identifying fatigue or changes in environmental conditions, allowing for a better understanding of runners.

The current study is focused on platinum recovery from the secondary sources of end-of-life heavy-duty diesel oxidation catalysts (DOCs) and heavy-duty catalyzed diesel particulate filters (c-DPFs) in order to reduce the supply–demand gap within the European Union. The extraction of platinum was based on a hydrometallurgical single-step low acidity leaching system (HCl-H2O2-NaCl) and a calcination step that takes place before the leaching process. The parameters of calcination and leaching process were thoroughly investigated in order to optimize recovery efficiency. The optimized results proved that a calcination step (at 800 °C for 2 h) improves the recovery efficiency by a factor of 40%. In addition, optimal Pt recovery yield was achieved after 3 h of leaching at 70 °C, with a solid-to-liquid (S/L) ratio of 70 g/100 mL (70%) and 3 M HCl-1% vol H2O2-4.5 M NaCl as leaching conditions. The optimum Pt recovery yield was 95% and 75% for DOC and c-DPF, respectively. Since the secondary feedstock investigated is highly concentrated in platinum, the pregnant solution can be used as a precursor for developing new Pt-based catalytic systems.

To examine whether cause, severity, and frequency of traumatic brain injury (TBI) increase risk of postdeployment tinnitus when accounting for comorbid posttraumatic stress disorder.Self-report and clinical assessments were done before and after an "index" deployment to Iraq or Afghanistan.Assessments took place on Marine Corps bases in southern California and the VA San Diego Medical Center. Participants were 1647 active-duty enlisted Marine and Navy servicemen who completed pre- and postdeployment assessments of the Marine Resiliency Study. The main outcome was the presence of tinnitus at 3 months postdeployment.Predeployment TBI increased the likelihood of new-onset postdeployment tinnitus (odds ratio [OR] = 1.86; 95% confidence interval [CI], 1.28-2.70). Deployment-related TBIs increased the likelihood of postdeployment tinnitus (OR = 2.65; 95% CI, 1.19-5.89). Likelihood of new-onset postdeployment tinnitus was highest for those who were blast-exposed (OR = 2.93; 95% CI, 1.82-6.17), who reported moderate-severe TBI symptoms (OR = 2.22; 95% CI, 1.22-3.40), and who sustained multiple TBIs across study visits (OR = 2.27; 95% CI, 1.44-4.24). Posttraumatic stress disorder had no effect on tinnitus outcome.Participants who were blast-exposed, sustained multiple TBIs, and reported moderate-severe TBI symptoms were most at risk for new-onset tinnitus.

ImportanceDisrupted autonomic nervous system functioning as measured by heart rate variability (HRV) has been associated with posttraumatic stress disorder (PTSD). It is not clear, however, whether reduced HRV before trauma exposure contributes to the risk for development of PTSD.ObjectiveTo examine whether HRV before combat deployment is associated with increased risk of a PTSD diagnosis after deployment when accounting for deployment-related combat exposure.Design, setting, and participantsBetween July 14, 2008, and May 24, 2012, active-duty Marines were assessed 1 to 2 months before a combat deployment and again 4 to 6 months after their return. The first phase of the Marine Resiliency Study (MRS-I) included 1415 male Marines, 59 of whom developed PTSD after deployment. Participants in the second phase of the Marine Resiliency Study (MRS-II) included 745 male Marines, 25 of whom developed PTSD after deployment. Analysis was conducted from November 25, 2013, to April 16, 2015.Main outcomes and measuresPredeployment HRV was measured via finger photoplethysmography during a 5-minute period of rest. Frequency-domain measures of HRV were generated. Diagnosis of PTSD was determined using the Clinician-Administered PTSD Scale.ResultsAfter accounting for deployment-related combat exposure, lower HRV before deployment as measured by an increased low-frequency (LF) to high-frequency (HF) ratio of HRV was associated with risk of PTSD diagnosis after deployment (combined MRS-I and MRS-II cohort meta-analysis odds ratio, 1.47; 95% CI, 1.10-1.98; P = .01). The prevalence of postdeployment PTSD was higher in participants with high predeployment LF:HF ratios (15.8% [6 of 38 participants]) compared with participants who did not have high LF:HF ratios (3.7% [78 of 2122 participants]).Conclusions and relevanceThis prospective longitudinal study provides initial and modest evidence that an altered state of autonomic nervous system functioning contributes to PTSD vulnerability, taking into account other key risk factors. If these findings are replicated, interventions that change autonomic nervous system function may open novel opportunities for prevention and treatment of PTSD.