89 research outputs found
Safety in Alpine Helicopter Rescue Operations—Minimal Requirements of Alpine Skills for Rescue Personnel
Objective: There is a lack of data to establish minimal requirements for technical alpine climbing skills needed by rescue teams involved in alpine helicopter rescue operations to perform such operations safely. Methods: A year of rescue operations (N = 2731) were investigated for the technical difficulties of the terrain. The difficulties were graded according to the Union Internationale des Associations d'Alpinisme (UIAA) scale for rocky terrain and steepness for ice slopes. Results: For 99.7% of the operations, the terrain could be accurately evaluated. In at least 30.7% of all rescue operations, personal advanced alpine climbing skills were required for the rescue personnel, and in 6.0%, the difficulties of the rocky terrain correspond to UIAA scale grade III with another 2.4% to UIAA grade IV or above. About 1.5% of all operations took place in ice faces steeper than 50°. Conclusions: To be able to manage 90% of all operations safely, all crew members, except the pilot, must be competent at climbing rock terrain of UIAA scale grade IV and ice of 50° steepness using appropriate rescue, rope, and belaying techniques. These recommendations include a technical safety margin for adverse conditions, such as bad weathe
Психологические особенности защитно-совладающего поведения сотрудников государственного пожарного надзора и пожарных частей ГПС МЧС России
Risks to Young Volunteers in International Social Projects
Background: The number of young volunteers in international social projects has increased significantly with governmental and non-governmental project support. This paper investigates the hypothesis that the preventative medical advice currently given prior to departure is inadequate because the risk profile of young persons (<30 years) differs from that of the general population. Methods: A retrospective cross-sectional study was performed with participants of international social projects. A specific questionnaire was developed; inclusion criteria were age between 18 and 30 years at departure and a duration with the project of at least 6 months. Results: One hundred and fifty-three data sets could be evaluated. Fifty-three percent were females; the destinations were as follows: 65.4% to Asia, 14.4% to Africa, and 10.5% to Latin America. The mean age was 20 years. Ninety percent of the participants received some kind of advice in travel medicine prior to departure. The vaccination rate was quite good, but pertussis (13.7%), yellow fever (80%), typhoid fever (54%), and rabies (49.7%) should be improved when travelling to high-risk regions. Food is a very important potential source of problems as 66% receive catering by the project, 56.2% from street stalls, and 44% were regularly invited to dine with locals. In Africa, only two-thirds of the participants of projects had regular access to safe water and the sanitary facilities were also poor; 51.7% of respondents reported new sexual contacts (one to more than six new partners). In most cases, condoms were used, but there were two unintended pregnancies. Conclusions: We conclude that young people need to be targeted with specialized advice for health and safety while abroad. This should highlight age-specific risks compared to advice for a more general population. Vaccination status should be improved for some regions and disease
Development Of An 80'-Diameter Ribbon Drogue Parachute For The NASA X-38 Vehicle
The NASA X-38 program required a larger, more robust drogue parachute. A multi-organizational team from NASA, Sandia National Laboratories, United Space Alliance, and Pioneer Aerospace Corporation has developed and tested a new 80-ft.-dia., quarter-spherical, ribbon drogue parachute. The design requirements, design specifics, margin analyses, and results of testing are all discussed herein. Some of the weight advantages of switching from Kevlar to Zylon for radial, line and riser materials are presented
Low Velocity Airdrop Tests of an X-38 Backup Parachute Design
The NASA Johnson Space Center's X-38 program designed a new backup parachute system to recover the 25,000 lb X-38 prototype for the Crew Return Vehicle spacecraft. Due to weight and cost constraints, the main backup parachute design incorporated rapid and low cost fabrication techniques using off-the-shelf materials. Near the vent, the canopy was constructed of continuous ribbons, to provide more damage tolerance. The remainder of the canopy was a constructed with a continuous ringslot design. After cancellation of the X-38 program, the parachute design was resized, built, and drop tested for Natick Soldiers Center's Low Velocity Air Drop (LVAD) program to deliver cargo loads up to 22,000 lbs from altitudes as low as 500 feet above the ground. Drop tests results showed that the 500-foot LVAD parachute deployment conditions cause severe skirt inversion and inflation problems for large parachutes. The bag strip occurred at a high angle of attack, causing skirt inversion before the parachute could inflate. The addition of a short reefing line prevented the skirt inversion. Using a lower porosity in the vent area, than is normally used in large parachutes, improved inflation. The drop testing demonstrated that the parachute design could be refined to meet the requirements for the 500-foot LVAD mission
Work in Hypoxic Conditions-Consensus Statement of the Medical Commission of the Union Internationale des Associations d'Alpinisme (UIAA MedCom)
Objectives: The Commission gives recommendations on how to provide health and safety for employees in different kinds of low oxygen atmospheres. So far, no recommendations exist that take into account the several factors we have outlined in this report. Methods: The health and safety recommendations of several countries were analysed for their strength and deficiencies. The scientific literature was checked (Medline, etc.) and evaluated for relevance of the topic. Typical situations of work in hypoxia were defined and their specific risks described. Specific recommendations are provided for any of these situations. Results: We defined four main groups with some subgroups (main risk in brackets): short exposure (pressure change), limited exposure (acute altitude disease), expatriates (chronic altitude disease), and high-altitude populations (re-entry pulmonary oedema). For healthy unacclimatized persons, an acute but limited exposure down to 13% O2 does not cause a health risk. Employees should be advised to leave hypoxic areas for any break, if possible. Detailed advice is given for any other situation and pre-existing diseases. Conclusions: If the specific risk of the respective type of hypoxia is taken into account, a pragmatic approach to provide health and safety for employees is possible. In contrast to other occupational exposures, a repeated exposure as often as possible is of benefit as it causes partial acclimatization. The consensus statement was approved by written consent in lieu of a meeting in July 200
Multi-epoch high-spectral-resolution observations of neutral sodium in 14 Type Ia supernovae
One of the main questions concerning Type Ia supernovae is the nature of the binary companion of the exploding white dwarf. A major discriminant between different suggested models is the presence and physical properties of circumstellar material at the time of explosion. If present, this material will be ionized by the ultraviolet radiation of the explosion and later recombine. This ionization-recombination should manifest itself as time-variable absorption features that can be detected via multi-epoch high-spectral-resolution observations. Previous studies have shown that the strongest effect is seen in the neutral sodium D lines. We report on observations of neutral sodium absorption features observed in multi-epoch high-resolution spectra of 14 Type Ia supernova events. This is the first multi-epoch high-resolution study to include multiple SNe. No variability in line strength that can be associated with circumstellar material is detected in the events presented in this paper. If we include previously published events, we find that ~18 per cent of the events in the extended sample exhibit time-variable sodium features associated with circumstellar material. We explore the implication of this study on our understanding of the progenitor systems of Type Ia supernovae via the current Type Ia supernova multi-epoch high-spectral-resolution sample
Geophagy as a means of survival for herbivores in anomalous rare-earth landscapes
The results of studies of the natural water composition, "edible" lands, forage vegetation, and animal tissues in the Sikhote-Alin, Altai Mountains, and the Caucasus, considering the literature data on Africa and Southeast Asia indicate that instinctive form of geophagy in animals (it seems, also in humans) develops in landscapes with an anomalously high and anomalously low concentration of rare earth elements (REE), with the disrupted ratio of LREEs and HREEs. The main reason for geophagy is to regulate the concentration and ratio of REE in the organism with the natural sorbents. The animals prefer sodium-containing analogs when they choose them
The type Iax supernova, SN 2015H A white dwarf deflagration candidate
We present results based on observations of SN 2015H which belongs to the small group of objects similar to SN 2002cx, otherwise known as type Iax supernovae. The availability of deep pre-explosion imaging allowed us to place tight constraints on the explosion epoch. Our observational campaign began approximately one day post-explosion, and extended over a period of about 150 days post maximum light, making it one of the best observed objects of this class to date. We find a peak magnitude of Mr = −17.27± 0.07, and a (Δm15)r = 0.69 ± 0.04. Comparing our observations to synthetic spectra generated from simulations of deflagrations of Chandrasekhar mass carbon-oxygen white dwarfs, we find reasonable agreement with models of weak deflagrations that result in the ejection of ~0.2 M⊙ of material containing ~0.07 M⊙ of 56Ni. The model light curve however, evolves more rapidly than observations, suggesting that a higher ejecta mass is to be favoured. Nevertheless, empirical modelling of the pseudo-bolometric light curve suggests that ≲0.6 M⊙ of material was ejected, implying that the white dwarf is not completely disrupted, and that a bound remnant is a likely outcome
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