515 research outputs found
Barriers and Opportunities for Residential Solar PV and Storage Markets - A Western Australian Case Study
Residents and businesses around the world are increasingly installing solar photovoltaic (PV) panels and battery storage systems, satisfying not just their interest in clean energy, but also taking advantage of reduced technology costs and mitigating against future electricity price rises. Solar PV panels coupled with storage systems present an opportunity to move towards a resilient, affordable, flexible and secure electricity network. Western Australia provides a unique set of conditions (isolated network, high solar radiation, and rising electricity prices), which has contributed to the rapid uptake of solar PV’s in the state. Yet, a number of issues are still obstructing the transition to renewables. Using Western Australia as a case study, this paper investigates the barriers inhibiting the network transformation and explores the role that solar PV and storage can play as a disruptive threat to the incumbent, centralised service model of electricity utilities
Fe and N self-diffusion in non-magnetic Fe:N
Fe and N self-diffusion in non-magnetic FeN has been studied using neutron
reflectivity. The isotope labelled multilayers, FeN/57Fe:N and Fe:N/Fe:15N were
prepared using magnetron sputtering. It was remarkable to observe that N
diffusion was slower compared to Fe while the atomic size of Fe is larger
compared to N. An attempt has been made to understand the diffusion of Fe and N
in non-magnetic Fe:N
Radiative transition rates and collision strengths for Si II
Aims. This work reports radiative transition rates and electron impact
excitation collision strengths for levels of the 3s23p, 3s3p2, 3s24s, and 3s23d
configurations of Siii. Methods. The radiative data were computed using the
Thomas-Fermi-Dirac-Amaldi central potential, but with the modifications
introduced by Bautista (2008) that account for the effects of electron-electron
interactions. We also introduce new schemes for the optimization of the
variational parameters of the potential. Additional calculations were carried
out with the Relativistic Hartree-Fock and the multiconfiguration Dirac-Fock
methods. Collision strengths in LS-coupling were calculated in the close
coupling approximation with the R-matrix method. Then, fine structure collision
strengths were obtained by means of the intermediate-coupling frame
transformation (ICFT) method which accounts for spin-orbit coupling effects.
Results. We present extensive comparisons between the results of different
approximations and with the most recent calculations and experiment available
in the literature. From these comparisons we derive a recommended set of gf-
values and radiative transition rates with their corresponding estimated
uncertainties. We also study the effects of different approximations in the
representation of the target ion on the electron-impact collision strengths.
Our most accurate set of collision strengths were integrated over a Maxwellian
distribution of electron energies and the resulting effective collision
strengths are given for a wide range of temperatures. Our results present
significant differences from recent calculations with the B-spline
non-orthogonal R-matrix method. We discuss the sources of the differences.Comment: 6 figures, 5 tables within text, 2 electronic table
“Pure” severe aortic stenosis without concomitant valvular heart diseases:echocardiographic and pathophysiological features
Purpose!#!In echocardiography the severity of aortic stenosis (AS) is defined by effective orifice area (EOA), mean pressure gradient (mPG!##!Methods and results!#!Patients (n = 306) with asymptomatic (n = 133) and symptomatic (n = 173) 'pure' severe AS (mean age 78 ± 9.5 years) defined by indexed EOA < 0.6 cm!##!Conclusion!#!In patients with 'pure' AS according to current guidelines the presence of combined LVH, DD and PAH as accepted pathophysiological sequelae of severe AS cannot be confirmed. Probably, the detection of these secondary cardiac alterations might improve the diagnostic algorithm to avoid overestimation of AS severity
Important Historical Efforts at Emergency Department Categorization in the United States and Implications for Regionalization
This article is drawn from a report created for the American College of Emergency Physicians (ACEP) Emergency Department (ED) Categorization Task Force and also reflects the proceedings of a breakout session, “Beyond ED Categorization—Matching Networks to Patient Needs,” at the 2010 Academic Emergency Medicine consensus conference, “Beyond Regionalization: Integrated Networks of Emergency Care.” The authors describe a brief history of the significant national and state efforts at categorization and suggest reasons why many of these efforts failed to persevere or gain wider implementation. The history of efforts to categorize hospital (and ED) emergency services demonstrates recognition of the potential benefits of categorization, but reflects repeated failures to implement full categorization systems or limited excursions into categorization through licensing of EDs or designation of receiving and referral facilities. An understanding of the history of hospital and ED categorization could better inform current efforts to develop categorization schemes and processes.ACADEMIC EMERGENCY MEDICINE 2010; 17:e154–e160 © 2010 by the Society for Academic Emergency MedicinePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79214/1/j.1553-2712.2010.00931.x.pd
Risk factors for early mortality in patients with pulmonary tuberculosis admitted to the emergency room.
Abstract Background and objectives Mortality of patients with pulmonary tuberculosis (TB) admitted to emergency departments is high. This study was aimed at analysing the risk factors associated with early mortality and designing a risk score based on simple parameters. Methods This prospective case-control study enrolled patients admitted to the emergency department of a referral TB hospital. Clinical, radiological, biochemical and microbiological risk factors associated with death were compared among patients dying within one week from admission (cases) and those surviving (controls). Results Forty-nine of 250 patients (19.6%) experienced early mortality. Multiple logistic regression analysis showed that oxygen saturation (SaO2) ≤90%, severe malnutrition, tachypnoea, tachycardia, hypotension, advanced disease at chest radiography, severe anaemia, hyponatremia, hypoproteinemia and hypercapnia were independently and significantly associated with early mortality. A clinical scoring system was further designed to stratify the risk of death by selecting five simple parameters (SpO2 ≤ 90%, tachypnoea, hypotension, advanced disease at chest radiography and tachycardia). This model predicted early mortality with a positive predictive value of 94.88% and a negative predictive value of 19.90%. Conclusions The scoring system based on simple parameters may help to refer severely ill patients early to a higher level to reduce mortality, improve success rates, minimise the need for pulmonary rehabilitation and prevent post-treatment sequelae
Optical and near-infrared recombination lines of oxygen ions from Cassiopeia A knots
Context. Fast-moving knots (FMK) in the Galactic supernova remnant Cassiopeia
A consist mainly of metals and allow to study element production in supernovae
and shock physics in great detail. Aims. We work out theoretically and suggest
to observe previously unexplored class of spectral lines -- metal recombination
lines in optical and near-infrared bands -- emitted by the cold ionized and
cooling plasma in the fast-moving knots. Methods. By tracing ion radiative and
dielectronic recombination, collisional -redistribution and radiative
cascade processes, we compute resulting oxygen, silicon and sulphur
recombination line emissivities. It allows us to determine the oxygen
recombination line fluxes, based on the fast-moving knot model of Sutherland
and Dopita (1995b), that predicts existence of highly-ionized ions from
moderate to very low plasma temperatures. Results. The calculations predict
oxygen ion recombination line fluxes detectable on modern optical telescopes in
the wavelength range from 0.5 to 3 microns. Line ratios to
collisionally-excited lines will allow to probe in detail the process of rapid
cloud cooling after passage of a shock front, to test high abundances of O V
and O VI ions at low temperatures and measure them, to test existing
theoretical models of a FMK and to build more precise ones.Comment: 18 pages, 22 figures, version accepted by A&A. Electronic supplement
available at http://www.mpa-garching.mpg.de/~dima/CasA_ORL/e-sup
Truncating Variants in Titin Independently Predict Early Arrhythmias in Patients With Dilated Cardiomyopathy.
Direct and indirect effect of the COVID-19 pandemic on patients with cardiomyopathy
Objectives: (i) To evaluate the prevalence and hospitalisation rate of COVID-19 infections amongst patients with dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM) in the Royal Brompton & Harefield Hospital Cardiovascular Research Centre (RBHH CRC) Biobank. (ii) To evaluate the indirect impact of the pandemic on patients with cardiomyopathy through the Heart Hive COVID-19 study. (iii) To assess the impact of the pandemic on national cardiomyopathy-related hospital admissions. Methods: (i) 1,236 patients (703 DCM, 533 HCM) in the RBHH CRC Biobank were assessed for COVID-19 infections and hospitalisations; ii) 207 subjects (131 cardiomyopathy, 76 without heart disease) in the Heart Hive COVID-19 study completed online surveys evaluating physical health, psychological wellbeing, and behavioural adaptations during the pandemic; (iii) 11,447 cardiomyopathy-related hospital admissions across NHS England were studied from NHS Digital Hospital Episode Statistics over 2019-2020. Results: A comparable proportion of patients with cardiomyopathy in the RBHH CRC Biobank had tested positive for COVID-19 compared with the UK population (1.1% vs 1.6%, p=0.14), but a higher proportion of those infected were hospitalised (53.8% vs 16.5%, p=0.002). In the Heart Hive COVID-19 study, more patients with cardiomyopathy felt their physical health had deteriorated due to the pandemic than subjects without heart disease (32.3% vs 13.2%, p=0.004) despite only 4.6% of the cardiomyopathy cohort reporting COVID-19 symptoms. A 17.9% year-on-year reduction in national cardiomyopathy-related hospital admissions was observed in 2020. Conclusion: Patients with cardiomyopathy had similar reported rates of testing positive for COVID-19 to the background population, but those with test-proven infection were hospitalised more frequently. Deterioration in physical health amongst patients could not be explained by COVID-19 symptoms, inferring a significant contribution of the indirect consequences of the pandemic
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