Solar energetic particle events: phenomenology and prediction

Solar energetic particle events can cause major disruptions to the operation of spacecraft in earth orbit and outside the earth's magnetosphere and have to be considered for EVA and other manned activities. They may also have an effect on radiation doses received by the crew flying in high altitude aircraft over the polar regions. The occurrence of these events has been assumed to be random, but there would appear to be some solar cycle dependency with a higher annual fluence occurring during a 7 year period, 2 years before and 4 years after the year of solar maximum. Little has been done to try to predict these events in real-time with nearly all of the work concentrating on statistical modelling. Currently our understanding of the causes of these events is not good. But what are the prospects for prediction? Can artificial intelligence techniques be used to predict them in the absence of a more complete understanding of the physics involved? The paper examines the phenomenology of the events, briefly reviews the results of neural network prediction techniques and discusses the conjecture that the underlying physical processes might be related to self-organised criticality and turbulent MHD flows

Hazes and clouds in a singular triple vortex in Saturn's atmosphere from HST/WFC3 multispectral imaging

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Temperature changes in serial casting in the treatment of clubfoot

INTRODUCTION: Idiopathic clubfoot (talipes equinovarus) is a congenital deformity of the foot. The common treatment consists of serial manipulation and casting, known as the Ponseti method, which is started in the first week after birth. After an average of five cast changes and often a percutaneous Achilles tenotomy the deformity is corrected [1]. An abduction orthosis is worn for several years to prevent relapse. The application of plaster cast includes soaking the roll in lukewarm water which starts the exothermic curing reaction. After the plaster has cured the surplus water evaporates, which is an endothermic process. Heat is drawn from the surrounding but also from the patient. One case study describes observed hypothermia after the application of a plaster jacket for immobilization of the cervical spine [2]. In a survey among parents (unreported, 49 respondents) a number of parents mentioned that their child seemed to feel cold the first hours after a new cast had been applied. The aim of current study is to investigate the temperature changes underneath the cast in the treatment of clubfoot with the Ponseti method. METHODS: A 1-wire DS1825 digital thermometer (Maxim Integrated, San Jose, CA, USA) was used to measure the temperature underneath the cast. The sensor was placed underneath the sole of the foot and attached to a custom made data logger which stored time and temperature data every 10 minutes for a full week. Dip duration was calculated as the time from the moment the first maximum was reached until the temperature reached the mean value of the last 6 days. T-Tests were used to test the temperature difference for statistical significance.According to the Medical ethical evaluation committee of the UMCG the study does not fall under the Medical Research Involving Human Subjects act. RESULTS AND DISCUSSION: Preliminary results of the first seven measurements in four subjects (age 2-30d, all boys, 2 bilateral) are presented in Figure 1. Figure 1: Typical measurement of the temperature underneath the cast during the first 24 hours after casting.After an initial temperature increase after the application of the plaster cast, a decrease was visible in all measurements (p < 0.000). This dip reached a minimum of 23-33°C and lasted 5.9-16h before reaching a relatively stable 34-37°C. During the ISB2017 the additional results of the remaining scheduled measurements will be presented. CONCLUSIONSA considerable decrease in skin temperature was observed after the application of long leg casts in the treatment of clubfoot. Especially in bilateral cases this might cause discomfort or even hypothermia. ACKNOWLEDGEMENTS: This study has been supported by the Dutch Technology Foundation

Reanalyzing Jupiter ISO/SWS Data through a More Recent Atmospheric Model

The study of isotopic ratios in planetary atmospheres gives an insight into the formation history and evolution of these objects. The more we can constrain these ratios, the better we can understand the history and future of our solar system. To help in this endeavour, we used Infrared Space Observatory Short Wavelength Spectrometer (ISO/SWS) Jupiter observations in the 793–1500 cm−1 region together with the Nonlinear Optimal Estimator for MultivariatE Spectral analySIS (NEMESIS) radiative transfer suite to retrieve the temperature–pressure profile and the chemical abundances for various chemical species. We also used the 1500–2499 cm−1 region to determine the cloud and aerosol structure of the upper troposphere. We obtained a best-fit simulated spectrum with 2/=0.47 for the 793–1500 cm−1 region and 2/=0.71 for the 1500–2499 cm−1 region. From the retrieved methane abundances, we obtained, within a 1 uncertainty, a 12C/13C ratio of 84 ± 27 and a D/H ratio of (3.5 ± 0.6) × 10−5, and these ratios are consistent with other published results from the literature.This research was funded by the Portuguese Fundação Para a Ciência e Tecnologia through the research grants UIDB/04434/2020 and UIDP/04434/2020 as well as a fellowship grants 2021.04584.BD and 2022.09859.BD

Wind-tunnel pressure measurements on model-scale rigid downwind sails

This paper describes an experiment that was carried out in the Twisted Flow Wind Tunnel at The University of Auckland to measure a detailed set of pressure distributions on a rigid 1/15th scale model of a modern asymmetric spinnaker. It was observed that the pressures varied considerably up the height of the spinnaker. The fine resolution of pressure taps allowed the extent of leading edge separation bubbles, pressure recovery region, and effect of sail curvature to be observed quite clearly. It was found that the shape of the pressure distributions could be understood in terms of conventional aerodynamic theory. The sail performed best at an apparent wind angle of about 55°, which is its design angle, and the effect of heel was more pronounced near the head than the foot

Long-term follow-up after attempted angioplasty of saphenous vein grafts: the Thoraxcenter experience 1981-1988

Between 1981 and 1988, 107 percutaneous transluminal coronary angioplasty (PTCA) procedures, including repeat PTCA, were performed in 84 patients with previous coronary artery bypass grafting (CABG). Fifty-nine patients underwent a first angioplasty of the vein graft alone, and 25 underwent a first PTCA of the graft and one or more native vessels. Seventeen patients underwent two procedures, four patients three procedures and one patient four procedures. In 84 first angioplasties, 133 lesions were attempted; 40 lesions in native vessels and 93 graft lesions (28 ostial stenoses, 33 shaft stenoses, and 32 stenoses at the distal anastomosis). Three patients died during their hospital stay. Two patients underwent emergency CABG. Seven patients sustained an acute myocardial infarction (AMI), among whom five underwent a PTCA of an occluded vessel. The clinical primary success rate per patient was 82%. After five years, 70% of patients were alive. At a median follow-up of 2.1 years, 41% of patients were alive and event-free (no AMI, no repeat CABG, no repeat PTCA). Symptomatic improvement was maintained in 36% of patients. Angioplasty of grafts may be an alternative to re-operation in selected patients with previous bypass surgery

Dynamic measurements of pressures, sail shape and forces on a full-scale spinnaker

This work presents a full-scale experimental study on a sailing yacht in downwind conditions with simultaneous time-resolved measurements of pressures, sail shape and loads. Those on-water experiments on a J/80 class yacht permit the dynamic behaviour of the fluid structure system made of a light cloth sail and highly curved flow to be investigated. Aerodynamic forces on the asymmetric spinnaker were determined from pressure distribution and shape measurements and also from strain gauges located on the corners of the sail. Both time-averaged and instantaneous data are analysed. The time-averaged pressures and forces were studied according to the apparent wind angle. The pressure distribution and thus the loads tend to decrease when the apparent wind angle is increased. The standard deviation of pressures was largest near the luff, decreasing downstream. Simultaneous time series recordings of the pressure distributions, flapping sail shapes, and forces in the sheets show a strong correlation. Flapping of spinnaker creates pressure peaks at the leading edge, increasing the aerodynamic forces dynamically by 50 to 70%. These results will also give reliable benchmark data to validate unsteady fluid structure interaction predictions from numerical simulations of downwind sails

Uranus's Northern Polar Cap in 2014

In October and November 2014, spectra covering the 1.436 – 1.863-μm wavelength range from the SINFONI Integral Field Unit Spectrometer on the Very Large Telescope showed the presence of a vast bright North polar cap on Uranus, extending northward from about 40ºN and at all longitudes observed. The feature, first detected in August 2014 from Keck telescope images, has a morphology very similar to the southern polar cap that was seen to fade before the 2007 equinox. At strong methane-absorbing wavelengths (for which only the high troposphere or stratosphere is sampled) the feature is not visible, indicating that it is not a stratospheric phenomenon. We show that the observed northern bright polar cap results mainly from a decrease in the tropospheric methane mixing ratio, rather than from a possible latitudinal variation of the optical properties or abundance of aerosol, implying an increase in polar downwelling near the tropopause level

An intense narrow equatorial jet in Jupiter’s lower stratosphere observed by JWST

The atmosphere of Jupiter has east–west zonal jets that alternate as a function of latitude as tracked by cloud motions at tropospheric levels. Above and below the cold tropopause at ~100 mbar, the equatorial atmosphere is covered by hazes at levels where thermal infrared observations used to characterize the dynamics of the stratosphere lose part of their sensitivity. James Webb Space Telescope observations of Jupiter in July 2022 show these hazes in higher detail than ever before and reveal the presence of an intense (140 m s−1) equatorial jet at 100–200 mbar (70 m s−1 faster than the zonal winds at the cloud level) that is confined to ±3° of the equator and is located below stratospheric thermal oscillations that extend at least from 0.1 to 40 mbar and repeat in multiyear cycles. This suggests that the new jet is a deep part of Jupiter’s Equatorial Stratospheric Oscillation and may therefore vary in strength over time.JWST-ERS-01373, NASA/ESA Hubble Space Telescope programmes no. 16913, 15502 and 16790, PID2019-109467GB-I00 funded by MCIN/AEI/10.13039/501100011033/, Grupos Gobierno Vasco IT1742-22. I.d.; European Research Council Consolidator Grant (under the European Union’s Horizon 2020 research and innovation programme, grant agreement no. 723890), STFC PhD Studentship, NASA grants 80NSSC21K1418 and 80NSSC19K0894

Probable detection of hydrogen sulphide (H₂S) in Neptune’s atmosphere

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