Single-stage, single-phase, ac–dc buck–boost converter for low-voltage applications

The suitability of a single-stage ac–dc buck–boost converter for low-voltage applications is investigated. In-depth discussion and analysis of the converter's operating principle, basic relationships that govern converter steady-state operation and details of the necessary control structures needed to comply with the grid code are provided. The validity of the proposed system is confirmed using power system computer aided design (PSCAD)/electromagnetic transients including DC (EMTDC) simulations, and is substantiated experimentally. The buck–boost converter under investigation has good dynamic performance in both buck and boost modes, and ensures near unity input power factor over the full operating range, whilst having fewer devices and passive elements than other published versions of the buck–boost converter

Reporting radiographers in Europe survey: An overview of the role within the European Federation of Radiographer Society (EFRS) member countries

Introduction Reporting radiographers undertake an important role in healthcare and for the radiographer profession in general. First introduced in the United Kingdom, reporting radiographers are now practicing in several other European countries. Our objective was to investigate the workforce of reporting radiographers across the European Federation of Radiographer Societies (EFRS) community. Method and material A voluntary anonymous 34 item electronic survey was distributed online using social media accounts such as Twitter, Facebook and LinkedIn covering a wide range of topics relating to professional role, advanced practice, education, and seniority. The questionnaire was distributed during a 12-week period in 2022. Result A total of 345 individual responses were received from 15 countries with majorities of respondent from United Kingdom (n = 245, 71%) and Denmark (n = 66, 19%). Mean age was 41.9 (S.D 9.8), similar for females, 42.5 (S.D 9.0) and men 40.9 years (S.D 9.7). Most reporting radiographers worked in public hospitals (90%). The vast majority of the respondents (n = 270, n = 94%) authored and signed their own clinical reports while a minority (n = 18, 6%) stated that their reports were checked by radiologists. Conclusion The survey highlights the scope of practice of reporting radiographers working in Europe. Reporting is becoming a career path for an increasing number of radiographers across Europe and there is assess to academic education and clinical support. Implication for practice Reporting radiographers fulfil an important role within the current demands of healthcare. This demand is likely to increase in the future, and therefore it is vital that there is some form of standardisation in the level of education that this group of healthcare professionals receive

The Effect of Participation in Organized Soccer on Fitnessgram Scores in 11-12 Year Old Girls

Purpose: Childhood obesity is increasing at an alarming rate throughout the United States and has been associated with multiple health complications such as heart disease and diabetes. Due to these increasing rates and health effects, there is a need to determine effective methods to measure physical activity as well as promote physical activity. One form of determining a child\u27s level of fitness is through the Fitnessgram. This study was designed to determine if formally testing fitness levels with the Fitnessgram in 11-12 year old girls participating in organized soccer is correlated with changes in fitness levels from pre-season to post-season, determine if using a measure such as the Fitnessgram influences the motivation to participate in organized and nonorganized physical activities, and determine if girls participating in organized soccer have higher fitness levels when compared to normative data. Subjects: Subjects were recruited from a soccer club and consisted of four female soccer players ages 11 to 12. Inclusion was based on participation in organized girls soccer and exclusion was based on parent/guardian and/or player\u27s refusal to consent to participation. Instrumentation: The Fitnessgram was used to provide feedback on whether or not the child achieved the criterion referenced age and gender specific standards for physical activity or fitness. In addition, participants were asked to complete questionnaires relative to the study. Procedure: Fitnessgram protocol was followed to evaluate strength, flexibility, body composition, and endurance. Subjects completed six tests both pre and post season which included curl-ups, trunk lifts, push-ups, PACER, skinfold measurements and sit and reach. Data Analysis: A related sample t-test compared pre and post-season measurements for curl-ups, trunk lift, push-ups, PACER test, and sit and each measurements. Results: Results of this study revealed no significant difference in preseason Fitnessgram scores compared to post-season scores. Conclusion and Clinical Implications: A major focus of physical therapy is to promote health and wellness across the lifespan. This includes advocating the benefits of exercise, encouraging participation in physical activity, and educating on the risks of obesity. In the future health professionals as well and educators could utilize the Fitnessgram to provide an objective measure of a child\u27s fitness level in reference to standardized age and gender specific norms

Cognitive ability does not predict objectively measured sedentary behaviour: evidence from three older cohorts

Higher cognitive ability is associated with being more physically active. Much less is known about the associations between cognitive ability and sedentary behavior. Ours is the first study to examine whether historic and contemporaneous cognitive ability predicts objectively measured sedentary behavior in older age. Participants were drawn from 3 cohorts (Lothian Birth Cohort, 1936 [LBC1936] [n = 271]; and 2 West of Scotland Twenty-07 cohorts: 1950s [n = 310] and 1930s [n = 119]). Regression models were used to assess the associations between a range of cognitive tests measured at different points in the life course, with sedentary behavior in older age recorded over 7 days. Prior simple reaction time (RT) was significantly related to later sedentary time in the youngest, Twenty-07 1950s cohort (p = .04). The relationship was nonsignificant after controlling for long-standing illness or employment status, or after correcting for multiple comparisons in the initial model. None of the cognitive measures were related to sedentary behavior in either of the 2 older cohorts (LBC1936, Twenty-07 1930s). There was no association between any of the cognitive tests and the number of sit-to-stand transitions in any of the 3 cohorts. The meta-analytic estimates for the measures of simple and choice RT that were identical in all cohorts (n = 700) were also not significant. In conclusion, we found no evidence that objectively measured sedentary time in older adults is associated with measures of cognitive ability at different time points in life, including cognitive change from childhood to older age

Energy Loss versus Shadowing in the Drell-Yan Reaction on Nuclei

We present a new analysis of the E772 and E866 experiments on the nuclear dependence of Drell-Yan (DY) lepton pair production resulting from the bombardment of $^2H$, Be, C, Ca, Fe, and W targets by 800 GeV/c protons at Fermilab. We employ a light-cone formulation of the DY reaction in the rest frame of the nucleus, where the dimuons detected at small values of Bjorken x_2 << 1 may be considered to originate from the decay of a heavy photon radiated from an incident quark in a bremsstrahlung process. We infer the energy loss of the quark by examining the suppression of the nuclear-dependent DY ratios seen as a function of projectile momentum fraction x_1 and dimuon mass M. Shadowing, which also leads to nuclear suppression of dimuons, is calculated within the same approach employing the results of phenomenological fits to deep inelastic scattering data from HERA. The analysis yields -dE/dz =2.73 +/- 0.37 +/- 0.5 GeV/fm for the rate of quark energy loss per unit path length, a value consistent with theoretical expectations including the effects of the inelastic interaction of the incident proton at the surface of the nucleus. This is the first observation of a nonzero energy loss effect in such experiments.Comment: 43 pages including 17 figure

High-­resolution bio-­ and chemostratigraphy of an expanded record of Oceanic Anoxic Event 2 (Late Cenomanian–Early Turonian) at Clot Chevalier, near Barrême, SE France (Vocontian Basin, SE France)

A newly located exposure of the Niveau Thomel, an organic-­‐rich level at the Cenomanian–Turonian boundary, provides a highly expanded record of Oceanic Anoxic Event (OAE) 2, excepted for the lower relatively condensed glauconite-­rich part of the section. The new locality, close to Barrême in the Vocontian Basin, SE France, is developed in deep-­water hemi-­pelagic facies (shales, marls, marly limestones, variably enriched in organic matter) and provides an improved understanding of palaeoceanographic events associated with OAE 2. Investigation of the biostratigraphy (nannofossils and planktonic foramininfera), organic and inorganic geochemistry (bulk carbonate δ18O, total organic carbon (TOC), bulk organic, biomarker-specific and carbonate δ13C, major and trace elements, and Rock-­Eval data) has allowed characterization of the sediments in great detail. The combined study further constrains the detailed relationship between bio-­ and chemostratigraphy (particularly with respect to the details of the well-­displayed positive carbon-­‐isotope excursion) for this interval. The section also provides new evidence, in the form of a positive oxygen-­isotope excursion and an offset between carbonate and organic-­carbon carbon-­isotope records, which confirms the importance of cooling accompanied by a drop in dissolved CO2 in near-­surface waters during the Plenus Cold Event that characterized the early part of OAE 2. Evidence for increased oxygenation of bottom waters, together with elevated concentrations of redox-­sensitive and chalcophilic elements registered elsewhere through the level of the Plenus Cold Event, may be reflected in enhanced concentrations of iron (in glauconite) and nickel in coeval strata from the Clot Chevalier section

Effects of post-capture ventilation assistance and elevated water temperature on sockeye salmon in a simulated capture-and-release experiment

The live release of wild adult Pacific salmon (Oncorhynchus spp.) following capture is a management tactic often used in commercial, aboriginal, and recreational fisheries. Fisheries capture and handling can be both exhausting and stressful to fish, which can limit their ability to swim and survive after release. As a result, researchers have assessed methods intended to improve post-release survival by assisting the flow of water over the gills of fish prior to release. Such approaches use recovery bags or boxes that direct water over the gills of restrained fish. This study evaluated a method of assisting ventilation that mimics one often employed by recreational anglers (i.e. holding fish facing into a current). Under laboratory conditions, wild Fraser River sockeye salmon (Oncorhynchus nerka) either received manual ventilation assistance for 1 min using a jet of water focused at the mouth or were left to recover unassisted following a capture-and-release simulation. A control group consisted of fish that were not exposed to the simulation or ventilation assistance. The experiment was conducted at 16 and 21°C, average and peak summer water temperatures for the Fraser River, and fish survival was monitored for 33 days. At 21°C, all fish perished within 3 days after treatment in all experimental groups, highlighting the consequences of handling adult sockeye salmon during elevated migration temperatures. Survival was higher at 16°C, with fish surviving on average 15-20 days after treatment. At 16°C, the capture-and-release simulation and ventilation assistance did not affect the survival of males; however, female survival was poor after the ventilation assistance compared with the unassisted and control groups. Our results suggest that the method of ventilation assistance tested in this study may not enhance the post-release survival of adult Fraser River sockeye salmon migrating in fresh water

Ductile-Phase Toughening of Brazed Joints

A heat treatment is presented that uses ductile-phase toughening to mitigate the effect of brittle intermetallics in a Ni-based braze alloy. The fracture resistance has been enhanced by creating a microstructure containing elongated ductile γ-(Ni) domains that align, preferentially, across the joint. The development of this beneficial microstructure is based on an understanding of the transient dissolution, isothermal solidification, and coarsening phenomena. Due to slow kinetics, the elimination of intermetallics by diffusion is avoided in favor of ductile domain formation through solidification control. The toughening has been attributed to a combination of bridging and process zone dissipation, enabled by the ductile phase

Comparative Analysis of Calcineurin Inhibitor-Based Methotrexate and Mycophenolate Mofetil-Containing Regimens for Prevention of Graft-versus-Host Disease after Reduced-Intensity Conditioning Allogeneic Transplantation

The combination of a calcineurin inhibitor (CNI) such as tacrolimus (TAC) or cyclosporine (CYSP) with methotrexate (MTX) or with mycophenolate mofetil (MMF) has been commonly used for graft-versus-host disease (GVHD) prophylaxis after reduced-intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (alloHCT), but there are limited data comparing efficacy of the 2 regimens. We evaluated 1564 adult patients who underwent RIC alloHCT for acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL), chronic myelogenous leukemia (CML), and myelodysplastic syndrome (MDS) from 2000 to 2013 using HLA-identical sibling (matched related donor [MRD]) or unrelated donor (URD) peripheral blood graft and received CYSP or TAC with MTX or MMF for GVHD prophylaxis. Primary outcomes of the study were acute and chronic GVHD and overall survival (OS). The study divided the patient population into 4 cohorts based on regimen: MMF-TAC, MMF-CYSP, MTX-TAC, and MTX-CYSP. In the URD group, MMF-CYSP was associated with increased risk of grade II to IV acute GVHD (relative risk [RR], 1.78; P <.001) and grade III to IV acute GVHD (RR, 1.93; P =.006) compared with MTX-TAC. In the URD group, use of MMF-TAC (versus MTX-TAC) lead to higher nonrelapse mortality. (hazard ratio, 1.48; P =.008). In either group, no there was no difference in chronic GVHD, disease-free survival, and OS among the GVHD prophylaxis regimens. For RIC alloHCT using MRD, there are no differences in outcomes based on GVHD prophylaxis. However, with URD RIC alloHCT, MMF-CYSP was inferior to MTX-based regimens for acute GVHD prevention, but all the regimens were equivalent in terms of chronic GVHD and OS. Prospective studies, targeting URD recipients are needed to confirm these results