Apparatus for measuring charged particle beam

An apparatus to measure the incident charged particle beam flux while effectively eliminating losses to reflection and/or secondary emission of the charged particle beam being measured is described. It comprises a sense cup through which the charged particle beam enters. A sense cone forms the rear wall of the interior chamber with the cone apex adjacent the entry opening. An outer case surrounds the sense cup and is electrically insulated therefrom. Charged particles entering the interior chamber are trapped and are absorbed by the sense cup and cone and travel through a current measuring device to ground

Analog to digital conversion using suprathreshold stochastic resonance

© 2005 COPYRIGHT SPIE--The International Society for Optical Engineering Copyright 2004 Society of Photo-Optical Instrumentation Engineers. This paper was published in Smart Structures, Devices, and Systems II, edited by Said F. Al-Sarawi, Proceedings of SPIE Vol. 5649 and is made available as an electronic reprint with permission of SPIE. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.We present an analysis of the use of suprathreshold stochastic resonance for analog to digital conversion. Suprathreshold stochastic resonance is a phenomenon where the presence of internal or input noise provides the optimal response from a system of identical parallel threshold devices such as comparators or neurons. Under the conditions where this occurs, such a system is effectively a non-deterministic analog to digital converter. In this paper we compare the suprathreshold stochastic resonance effect to conventional analog to digital conversion by analysing the rate-distortion trade-off of each.Mark D. McDonnell, Nigel G. Stocks, Charles E. M. Pearce, and Derek Abbot

Assessment of Corona/Arcing Hazard for Electron Beam Welding in Space Shuttle Bay at LEO for ISWE: Test Results

Test welds were made in argon over a range of pressures from 10-5 to 10-3 torr (the latter pressure an order of magnitude above pressures anticipated in the space shuttle bay during welding) with and without plasma on 304 stainless steel, 6Al-4V titanium, and 5456 aluminum in search of any possible unwanted electrical discharges. Only a faint steady glow of beam-excited atoms around the electron beam and sometimes extending out into the vacuum chamber was observed. No signs of current spiking or of any potentially dangerous electrical discharge were found

Charge Distributions in Metallic Alloys: a Charge Excess Functional theory approach

Charge Distributions in Metallic Alloys: a Charge Excess Functional theory approachComment: 13 pages, 5 figure

Formal Specification and Testing of a Management Architecture

The importance of network and distributed systems management to supply and maintain services required by users has led to a demand for management facilities. Open network management is assisted by representing the system resources to be managed as objects, and providing standard services and protocols for interrogating and manipulating these objects. This paper examines the application of formal description techniques to the specification of managed objects by presenting a case study in the specification and testing of a management architecture. We describe a formal specification of a management architecture suitable for scheduling and distributing services across nodes in a distributed system. In addition, we show how formal specifications can be used to generate conformance tests for the management architecture

Impact of long‐term management with sleep medications on blood pressure: An Australian national study

OnlinePublBackground: There is mixed evidence about the impact of long-term management with hypnotic medications on blood pressure (BP). Aim: To estimate the effect of short- and long-term management with benzodiazepine and z-drugs (BZD) on BP. Method: Open cohort study using deidentified electronic health records of 523,486 adult regular patients (42.3% males; mean age 59.0 ± 17.0 years) annually attending 402 Australian general practices between 2016 to 2018 (MedicineInsight database). Average treatment effects (ATE) of recorded incident BZD prescriptions in 2017 on systolic (SBP) and diastolic (DBP) BP after starting these prescriptions were computed using augmented inverse probability weighting (AIPW). Results: In 2017, 16,623 new cases of short-term management with BZD and 2532 cases of long-term management with BZD were identified (incidence 3.2% and 0.5%, respectively). The mean BP among those not treated with BZD (reference group) was 130.9/77.3 mmHg. Patients prescribed short-term BZD showed a slightly higher SBP (ATE 0.4; 95% CI 0.1, 0.7) and DBP (ATE 0.5; 95% CI 0.3, 0.7), while those on long-term BZD prescriptions showed lower SBP (ATE -1.1; 95% CI −2.0, −0.2), but no effect on DBP (ATE −0.1; 95% CI −0.8, 0.5). However, long-term BZD prescriptions showed a stronger BP-lowering effect among patients aged 65+ years (SBP ATE −2.5 [95% CI −3.8, −1.3]; DBP ATE −1.0 [95% CI −1.7, −0.2]), but almost no effect was observed among younger patients. Conclusion: Long-term management with BZD had a BP-lowering effect among older patients. These findings add new evidence to current recommendations on limiting long-term BZD management in the elderly.Mumtaz Begum, David Gonzalez-Chica, Carla Bernardo, Nigel Stock

Dynamics of defect formation

A dynamic symmetry-breaking transition with noise and inertia is analyzed. Exact solution of the linearized equation that describes the critical region allows precise calculation (exponent and prefactor) of the number of defects produced as a function of the rate of increase of the critical parameter. The procedure is valid in both the overdamped and underdamped limits. In one space dimension, we perform quantitative comparison with numerical simulations of the nonlinear nonautonomous stochastic partial differential equation and report on signatures of underdamped dynamics.Comment: 4 pages, LaTeX, 4 figures. Submitted to Physical Revie

Impact of funding influenza vaccination on coverage among Australian children: a national study using MedicineInsight, a large general practice database

Published Online 7 October 2019Influenza contributes to morbidity and mortality worldwide. Children are at a higher risk of influenza-related complications and vaccination promotes direct protection and limits transmission. This study aimed to explore influenza vaccination coverage among children in Australian general practice from 2015 to 2018, and patterns in coverage before and after the implementation of state-funded immunization programs. Data from 196,520 ‘active’ patients (3+ consultations in two consecutive years) aged <5 years from 542 Australian general practices were included (MedicineInsight database). Logistic regression models were used to identify associations between vaccination with patient and practice characteristics. The overall vaccination coverage increased more than five times from 2015 (3.9%) to 2018 (19.6%) and varied among states. Children attending practices located in the wealthiest areas were more likely to receive the vaccine and appeared to benefit most from the funding, as the increase in coverage from 2017 to 2018 was greater among them than those attending practices in the least advantaged areas (17 vs. 11 percentage points, respectively). This relationship was not evident when analyzing the patient’s socioeconomic level. In conclusion, free influenza vaccinations increase coverage in at-risk populations. Promotional campaigns may be required to maintain higher coverage and target practices located in low-income areas.Carla De Oliveira Bernardo, David Alejandro González-Chica, and Nigel Stock