Sheets In Space Research Articles

Designing of Lightweight and Ultrathin III‐V/Ge Solar Cells for Flexible Space and Terrestrial Photovoltaic Blankets

The method described in this article offers a simple and convenient way to obtain highly efficient, ultrathin, and flexible solar cells (SCs) based on III‐V/Ge heterostructures. This is achieved by thinning Ge to several tens, or even a few units of microns, which accounts for up to 95% of the total thickness and weight of a SC. The only low‐temperature thermal peelable tape REVALPHA as a temporary carrier supports and saves the heterostructure along the process route. The carrier is then easily and cleanly removed by heating without damaging the thinned SC. The temporary carrier provides a reliable transfer of the thinned SC with a developed low‐temperature (i.e., without annealing) indium back contact to an arbitrary light and flexible substrate (Kapton or carbon sheet). The possibility of creating highly efficient, ultrathin, and ultralight SCs on a flexible carrier is demonstrated using mass‐produced GaInP/Ga(In)As/Ge heterostructures. Based on the results obtained, a possible architecture and technology for assembling coupons from ultrathin solar cells based on any III‐V/Ge heterostructures on a Kapton or carbon carrier for space and terrestrial applications are proposed.

What is the best way to keep the patient warm during technical rescue? Results from two prospective randomised controlled studies with healthy volunteers

BackgroundAccidental hypothermia is a manifest problem during the rescue of entrapped victims and results in different subsequent problems as coagulopathy and wound infection. Different warming methods are available for the preclinicial use. However, their effectiveness has hardly been evaluated.MethodsIn a first step a survey among German fire brigades was performed with questions about the most used warming methods. In a second step two crossover studies were conducted. In each study two different warming method were compared with forced air warming – which is the most frequently used and highly effective warming method in operation rooms (Study A: halogen floodlight vs. forced air warming; Study B: forced air warming vs. fleece blanket). In both studies healthy volunteers (Study A: 30 volunteers, Study B: 32 volunteers) were sitting 60 min in a cold store. In the first 21 min there was no subject warming. Afterwards the different warming methods were initiated. Every 3 min parameters like skin temperature, core body temperature and cold perception on a 10-point numeric rating scale were recorded. Linear mixed models were fitted for each parameter to check for differences in temperature trajectories and cold perception with regard to the different warming methods.ResultsOne hundred fifty-one German fire brigades responded to the survey. The most frequently used warming methods were different rescue blankets (gold/silver, wool) and work light (halogen floodlights). Both studies (A and B) showed significantly (p < 0.05) higher values in mean skin temperature, mean body temperature and total body heat for the forced air warming methods compared to halogen floodlight respectively fleece blanket shortly after warming initiation. In contrast, values for the cold perception were significantly lower (less unpleasant cold perception) during the phase the forced air warming methods were used, compared to the fleece blanket or the halogen floodlight was used.ConclusionForced air warming methods used under the standardised experimental setting are an effective method to keep patients warm during technical rescue. Halogen floodlight has an insufficient effect on the patient’s heat preservation. In healthy subjects, fleece blankets will stop heat loss but will not correct heat that has already been lost.Trial registrationThe studies were registered retrospectively on 14/02/2022 on the German Clinical Trials registry (DRKS) with the number DRKS00028079.

Adsorption Capacity of Plastic Foils Suitable for Barrier Resuscitation

Chest compressions and ventilation attempts can generate aerosols during resuscitation. It is important to determine whether different materials suitable for the blanketing of cardiac arrest patients can diminish exposure to aerosols. In this study, three volatile organic compounds, ethanol, acetone, and isoprene, commonly found in human breath in moistened air, acted as substitutes for aerosols. Here, we present information on the adsorption of these volatiles to three blanketing materials: polyvinyl chloride, polyethylene, and aluminum coated polyethylene terephthalate. After exposure to the surfaces of these materials the test volatiles were quantified by the proton transfer reaction-time of flight-mass spectrometry. There was a trend towards a potentially higher reduction for acetone (p = 0.071) and isoprene (p = 0.050) on polyethylene, compared to polyvinyl chloride and aluminum coated polyethylene terephthalate during the rise interval. Adsorption capacity did not differ between the foils and was between 67% and 70%. From our studies, we propose that the aluminum-coated polyethylene terephthalate surface of space blankets prove adequate to diminish exposure to volatiles in moistened air, and hence to aerosols.

Rescue Blankets as Multifunctional Rescue Equipment in Alpine and Wilderness Emergencies-A Narrative Review and Clinical Implications.

The utilization of rescue blankets in pre-hospital emergency medicine exceeds protection from hypothermia and enhanced visibility by far. In this narrative review, we focus on emphasizing the alternative applications of these fascinating multifunctional tools in the pre-hospital setting. A literature search in PubMed® and Web of ScienceTM yielded 100 results (last update was on 8 July 2022), a total number of 26 of which were included in this narrative review. Nine articles assessing alternative functions of rescue blanket were further evaluated and described in more detail. In addition, we performed various experimental and observational trials to test the functionality of rescue practice in mountain emergency medicine. Newly fabricated rescue blankets proved to possess impressive robustness. We evaluated rescue blankets in their applicability to not only protect from hypothermia, but also as practical tools to treat catastrophic hemorrhage and bleeding limbs, to perform open pneumothorax chest seals in sucking chest wounds, to prevent damage to unprotected eyes on the glacier and as alternative instruments for transportation in the inaccessible areas. Rescue blankets are important rescue equipment in alpine and wilderness emergencies with multifunctional applications, and must be part of every personal medical kit.

Ultralow Emittance Thermal Radiation Barrier Achieved by a High-Contrast Grating Coating

Thermal radiative emission in vacuum is minimized using metal-backed flexible “space blankets” that have a theoretical minimum infrared emittance of 0.03. However, their presence under oxygenated and degradation-prone environments rapidly increases emittance due to metal oxidation, surface pitting, and implantation of contaminants. A monolithic dielectric coating composed of microscale periodic metasurface gratings on multilayers and metal thin film can achieve sub-1% total emittance. The minimum emittance can be tailored to any temperature-function blackbody emission, so long as the selected dielectric coating materials have near-zero absorption. Using computational optimization and theoretical understanding of high-contrast grating phase-shift mode conditions, we identified characteristic at-wavelength germanium gratings and a near-quarter-wave layer above a low-refractive-index infrared-transparent Fabry–Pérot multilayer interference cavity. This dual mechanism can achieve a room-temperature total emittance of 0.0085, paving a new theoretical minimum multilayer insulation effective conductance. As multilayer insulation, this coating offers total effective emittance of 0.0032 per pair of optimally mismatched grating surfaces. This ultrahigh reflection coating design can also be relevant in thermal management of refrigeration and electronic components.

Thin foil body-shield resuscitation barrier device to protect from blood: an experimental study

In times of collective concern about pandemics, body-shield resuscitation barrier devices are more and more considered to protect against transmission of different pathogens between rescuers and patients. The objective of this experimental study was to investigate the characteristics of blood drops dispersed on the surface of four different foils suitable for blanketing patients during resuscitation. We analyzed run-off characteristics of blood stains depending on surface properties of polyvinyl chloride, polyethylene, polyethylene terephthalate and aluminum-coated polyethylene terephthalate. Confocal fluorescence microscopy revealed less cellular density and lack of fibrin networks in blood stains on the four foil surfaces than on paper towel. Delayed clotting went along with larger areas of contamination indicating a greater likelihood of coming into contact with potential germs but a smaller chance of contracting an infection. Space blankets as obligatory components of first aid kits are readily available for rescuers and serve as a mechanical barrier between rescuers and patients during resuscitation.

Differences in the thermal properties and surface temperature of prehospital antihypothermia devices: an in vitro study

BackgroundPreventing and treating hypothermia in prehospital settings is crucial. Several products have been developed to prevent heat loss and actively warm patients in prehospital settings. We compared the efficacy and...

Prevention of hypothermia in trauma victims - the HYPOTRAUM 2 study.

Hypothermia is common in trauma patients. It contributes to increasing mortality rate. Hypothermia is multifactorial, favoured by exposure to cold, severity of the patient's state and interventions such as infusion of fluids at room temperature. To demonstrate that specific management of hypothermia (or of the risk of hypothermia) increases the number of trauma patients arriving at the hospital with a temperature >35°C. This is a prospective, multicentre, open-label, pragmatic, cluster randomized clinical trial of an expected 1,200 trauma patients included by 12 out-of-hospital mobile intensive care units (MICU). Trauma patients are included in a prehospital setting if they present at least one of the following criteria known to be associated with an increased incidence of hypothermia: ambient temperature <18°C, Glasgow coma scale <15, systolic arterial blood pressure <100mm Hg or body temperature <35°C. Patients are randomized, by cluster, to receive a conventional management or 'interventional' nursing management associating: continuous epitympanic temperature monitoring, early installation in the heated ambulance (temperature target >30°C controlled by infrared thermometer), protection by a survival blanket, and use of heated solutes (temperature objective >35°C controlled by infrared thermometer). The primary end point is the prevalence of hypothermia on arrival at the hospital. The hypothesis tested is a reduction from 20% to 13% in the prevalence of hypothermia. Secondary end points are to evaluate the interaction between the effectiveness of the measures taken and: (1) the severity of the patients assessed by the Revised Trauma Score; (2) the meteorological conditions when they are managed; (3) the time of care; and (4) therapeutic interventions. This trial will assess the effectiveness of an invasive, out-of-hospital, temperature management on the onset of hypothermia in moderate to severe trauma patients. Specific management of hypothermia is expected to decrease hypothermia in trauma patients.

Use of Medical Supplies at the Roskilde Festival 2016: A Prospective Observational Study.

Music festivals are popular events often including camping at the festival site. A mix of music, alcohol, drugs, and limited hygiene increases health risks. This study aimed to assess the use of medical supplies at a major music festival, thereby aiding planning at similar events in the future. The Medical Health Care Organization (MHCO) at Roskilde Festival 2016 (Denmark) collected prospective data on disposable medical supply use and injuries and illnesses presenting to the MHCO. A total of 12,830 patient presentations were registered by the MHCO and a total of 104 different types of disposable medical supplies were used by the MHCO from June 25, 2016 through July 3, 2016. Out of 12,830 cases, 594 individuals (4.6%) had a potential or manifest medical emergency, 6,670 (52.0%) presented with minor injuries, and 5,566 (43.4%) presented with minor illnesses. The overall patient presentation rate (PPR) was 99.0/1,000 attendees and the transport-to-hospital rate (TTHR) was 2.1/1,000 attendees. For medical emergencies, the most frequently used supplies were aluminum rescue blankets (n = 627), non-rebreather masks (n = 121), and suction catheters for an automatic suction unit (ASU) for airway management (n = 83). Most used diagnostic equipment were blood glucose test strips (n = 1,155), electrocardiogram electrodes (n = 960), and urinary test strips (n = 400). The most frequently used personal protection equipment were non-sterile gloves (n = 1,185 pairs) and sterile gloves (n = 189). This study demonstrates a substantial use of disposable medical supplies at a major music festival. The results provide aid for planning similar mass-gathering (MG) events.

Evaluación de un protocolo de prevención de la hipotermia durante anestesia general en perros domésticos sometidos a profilaxis dental

El incorrecto manejo térmico del paciente canino sometido a anestesia general puede generar complicaciones en la recuperación e inclusive presentar el riesgo de muerte. El objetivo fue evaluar un protocolo de prevención de la hipotermia en pacientes caninos sanos sometidos a anestesia general para la realización de un procedimiento de profilaxis dental. Para el método investigativo se reclutaron 10 pacientes para un ensayo clínico controlado de tipo cruzado por intención de tratamiento, a los pacientes se les sometió a dos procedimientos anestésicos, el primero sin ningún medio de mantenimiento de la normotermia, y el segundo procedimiento acompañado de un protocolo compuesto por precalentamiento durante 30 minutos a 28°C, manta reflectante Survival Blanket ® + luz radiante (foco infrarrojo de 250W) para minimizar la perdida de temperatura de los pacientes. Se evaluaron las temperaturas rectales (temperatura periférica) durante todo el perioperatorio (60 minutos) obtenidas en los 10 pacientes en ambas intervenciones, siendo estos datos analizados mediante una prueba estadística (T-Test) Como Resultados se encontró diferencias significativas entre aplicar y no aplicar dicho protocolo. Las diferencias estadísticamente significativas que se encontraron fueron: al final de la premedicación (p valor= 0.039), al inicio de la inducción (p valor = 0.041), y durante todo el mantenimiento (p valor= 0.008 – 0.013 – 0.012 – 0.005 – 0.008 – 0.005 – 0.005). Conclusiones. - se observó y demostró que combinar métodos activos y pasivos ayudan a minimizar la perdida de temperatura del paciente.

Rescue blankets hamper thermal imaging in search and rescue missions

Thermal imaging for unmanned aerial vehicles is used to search for victims in poor visibility conditions. We used a gimbal-mounted camera for thermo-radiation measurements of body temperature from persons covered with rescue blankets in the hibernal wilderness setting. Long-wave infrared radiation in the spectral range between 7500 and 13,500 nm was evaluated. Parts of this research have previously been published in a review on electromagnetic radiation reflectivity of rescue blankets (https://www.mdpi.com/2079-6412/10/4/375/htm). Surface temperature measurement was diminished by clothing, namely by 72.6% for fleece, by 82.2% for an additional down jacket and by 92.3% for an additional all-weather jacket, as compared to forehead temperature. Furthermore, we detected that a single-layer rescue blanket is sufficient to render recognition of a body shape impossible. With three layers covering a clothed body infrared transmission was almost completely blocked. However, rescue blankets increase visibility for thermal cameras due to high gradients in temperature. Conspicuously low temperatures from objects of 1 to 2 m length may indicate reflections from rescue blanket surfaces in a cold environment. Ideally, rescue blankets should be removed from the body to increase the chance of being located when using thermal imaging to search for victims in search and rescue missions.

High Tensile Strength Increases Multifunctional Use of Survival Blankets in Wilderness Emergencies

Metallic survival blankets are multifunctional medical devices frequently used to provide thermal insulation in sport and leisure activities and in emergency care. To assess further properties of survival blankets, we investigated their breaking strength under laboratory conditions. An experimental study was performed with 2 commercially available survival blankets used by emergency medical services. Breaking strength measured with a tensile testing machine was determined consecutively with 10 tests conducted per brand. Breaking strength (mean±SD) of the tested brands was 3.8±0.4 kN, (range: 2.8-4.1 kN) and 4.0±0.5 kN (range: 3.2-4.6 kN). When using the windlass of a commercially available tourniquet for the longitudinally folded survival blanket, the windlass bent at a force of 0.8 kN; when using a carabiner, the force exceeded 3.6 kN before failure occurred in both blanket brands. Both brands of survival blankets show impressive tensile strength, indicating that they have the potential to serve as temporary pelvic binders or even as makeshift tourniquets when urgent bleeding control is needed.

Rescue Blankets-Transmission and Reflectivity of Electromagnetic Radiation

Rescue blankets are medical devices made of a polyethylene terephthalate sheet coated with a thin aluminum layer. Blankets are used for protection against hypothermia in prehospital emergency medicine and outdoor sports, but totally different qualities are typical for these multi-functional tools. On the one hand, rescue sheets prevent hypothermia by reducing thermo-convection and diminishing heat loss from evaporation and thermal radiation. On the other hand, the sheets promote cooling by acting as a radiant barrier, by providing shade and even by increasing heat conduction when the sheet is in direct contact with the skin. As foils are watertight and windproof, they can function as vapor barriers and even as stopgap bivouac sacks. We evaluated three experimental studies, one on heat loss by rescue blankets according to surface color, one on transparency with ultraviolet radiation, high-energy visible light and visible light, and one on infrared radiation from rescue blankets. When evaluating the effects of different bands of the electromagnetic spectrum on rescue sheets, we focused on ultraviolet radiation (200–380 nm), high-energy visible light in the violet/blue band (380–450 nm), visible light (380–760 nm) and infrared radiation (7500–13,500 nm). Rescue sheets transmit between 1% and 8% of visible light and about 1% of ultraviolet B radiation (280–315 nm), providing sufficient transparency and adequate protection from snow blindness. Reflection of visible light increases detectability in search and rescue missions performed in good visibility conditions, while reflection of infrared radiation increases detectability in poor visibility conditions and provides protection against hypothermia.

Efficacy of rescue blanket versus conventional blanket in terms of preventing accidental hypothermia during patient transfer by emergency medical service: a randomized clinical trial

Objective: This study aimed to compare the efficacy of rescue blankets with conventional blankets in terms of preventing hypothermia in the pre-hospital setting. Methods: In this randomized clinical trial, patients older than 18 years old with Cold Discomfort Scale (CDS) &gt; 2, and those who were transferred to the emergency department (ED) by emergency medical service entered the study. Patients were randomly divided into two groups based on the type of transfer. In this regard, one group was transferred with rescue blankets and the other group was transferred with conventional blankets. The tympanic temperature in patients and CDS were recorded before the use of blanket (primary) and at the time of arrival in the ED (secondary). Results: Finally, 161 patients with the mean age of 45.31±19.8 years were included (63.4% were male). Totally, 88 cases (54.7%) were transferred with rescue blankets and 73 cases (45.3%) with conventional blankets. The mean of the primary tympanic temperatures in the rescue and conventional blanket groups were 36.20±0.84°C and 36.34±0.65°C, respectively (P=0.23). The mean of the primary CDS in rescue and conventional blanket groups were 6.55±1.95 and 5.89±2.29, respectively (P=0.05). Also, the mean of the secondary tympanic temperatures in the rescue and conventional blanket groups were 36.59±0.47°C and 36.76±0.48 °C, respectively (P=0.03). Besides, the mean of the secondary CDS in the rescue and conventional blanket groups were 2.64±2.80 and 2.41±1.29, respectively (P=0.48). Conclusion: According to the results, there is no significant difference in the tympanic temperature and CDS of the patients transferred with the rescue blanket compared with the conventional blanket.

Suppression of Antenna Backscatter on a Nanosat Using a Resistively Loaded FSS Absorber

A very thin microwave absorber that can be integrated into the outermost layer of thermal blankets is proposed as a means to electromagnetically decouple payload antennas from spacecraft platforms. The effectiveness of this concept is evaluated for a critical test case where a linearly polarized dipole antenna working at 10 GHz is placed at three different distances above the surface of a $\text{10 cm}$ Nanosat mock-up. This scenario is chosen as the dipole will radiate into both half spaces and any reflections from the vehicle onto which it is mounted will significantly affect its behavior. A resistively loaded frequency selective surface (FSS) absorber is employed to supress the energy contained in the antenna backlobes, and it is shown that the installed performance for all three geometries closely resembles the beam shape of the antenna in isolation. Experimental results have been obtained for one arrangement to confirm that the directive gain is increased by 18 dB in the boresight direction. The FSS absorber is composed of an array of resistively loaded hexagonal patches that are patterned on a 1.12 mm ( $\lambda /25$ ) thick foil-backed polyethylene terephthalate sheet to replicate the physical construction of commercially available space blankets.

Resistively loaded ultra‐thin FSS absorbers for radio‐frequency enhancement of spacecraft thermal blankets

This study reports the use of metal-backed frequency selective surface (FSS) absorbers as a means to control the scattering of electromagnetic energy from satellite platforms which are covered with thermal blankets. This is achieved by exploiting the similarity of the physical construction of this class of absorber and the dielectric clad foil-backed outermost layer of space blankets. Simulated results are presented for five absorber designs which are suitable for mechanical integration into the top surface of a multi-layer insulator. These were constructed using polyethylene terephthalate (PET) material with sheet thickness in the range 140 μ m ( λ / 213 ) − 1120 μ m ( λ / 25 ). The optimum performance around 10 GHz was obtained from an array of hexagonal patch elements with the conductivity of the silver plating adjusted to achieve the desired resistive loading. At normal incidence, the FSS-based structures presented −10 dB reflectivity bandwidths that are strongly dependent on the thickness of the PET sheet and vary between 2 and 16%. The design methodology is verified by measuring the radar backscatter from 140 and 1120 μ m thick absorbers in the frequency range 8–12 GHz.

A dynamic thermoregulatory material inspired by squid skin

Effective thermal management is critical for the operation of many modern technologies, such as electronic circuits, smart clothing, and building environment control systems. By leveraging the static infrared-reflecting design of the space blanket and drawing inspiration from the dynamic color-changing ability of squid skin, we have developed a composite material with tunable thermoregulatory properties. Our material demonstrates an on/off switching ratio of ~25 for the transmittance, regulates a heat flux of ~36 W/m2 with an estimated mechanical power input of ~3 W/m2, and features a dynamic environmental setpoint temperature window of ~8 °C. Moreover, the composite can manage one fourth of the metabolic heat flux expected for a sedentary individual and can also modulate localized changes in a wearer’s body temperature by nearly 10-fold. Due to such functionality and associated figures of merit, our material may substantially reduce building energy consumption upon widespread deployment and adoption.

Construction of a Low-cost Mobile Incubator for Field and Laboratory Use.

Incubators are essential for a range of culture-based microbial methods, such as membrane filtration followed by cultivation for assessing drinking water quality. However, commercially available incubators are often costly, difficult to transport, not flexible in terms of volume, and/or poorly adapted to local field conditions where access to electricity is unreliable. The purpose of this study was to develop an adaptable, low-cost and transportable incubator that can be constructed using readily available components. The electronic core of the incubator was first developed. These components were then tested under a range of ambient temperature conditions (3.5 °C - 39 °C) using three types of incubator shells (polystyrene foam box, hard cooler box, and cardboard box covered with a survival blanket). The electronic core showed comparable performance to a standard laboratory incubator in terms of the time required to reach the set temperature, inner temperature stability and spatial dispersion, power consumption, and microbial growth. The incubator set-ups were also effective at moderate and low ambient temperatures (between 3.5 °C and 27 °C), and at high temperatures (39 °C) when the incubator set temperature was higher. This incubator prototype is low-cost (< 300 USD) and adaptable to a variety of materials and volumes. Its demountable structure makes it easy to transport. It can be used in both established laboratories with grid power or in remote settings powered by solar energy or a car battery. It is particularly useful as an equipment option for field laboratories in areas with limited access to resources for water quality monitoring.

Human Subject Effects on Torsion Pendulum Oscillations: Further Evidence of Mediation by Convection Currents

When a human subject sits beneath a wire mesh, hemispheric torsion pendulum (TP) a rapid-onset series of oscillations at frequencies both higher and lower than the fundamental frequency of the TP have been consistently observed. This study was designed to replicate and extend prior findings that suggest the human subject effect on TP behavior is due to subject-generated, heat-induced convection currents. Effects on pendulum behavior were tested after draping an aluminized "space blanket" over the subject and by replacing the subject with a thermal mattress pad shaped to approximate the human form. Experiments were performed in a basic science university research laboratory. Real-time recordings and Fast Fourier Transform frequency spectra of pendulum oscillatory movement. The space blanket blocked, while the mattress pad mimicked, the human subject induced complex array of pendulum oscillations. Our findings support and strengthen previous results that suggest the effects of human subjects on behavior of a torsion pendulum are mediated by body-heat-induced air convection rather than an unknown type of biofield.

A torso model comparison of temperature preservation devices for use in the prehospital environment

BackgroundHypothermia is an independent predictor of increased morbidity and mortality in patients with trauma. Several strategies and products have been developed to minimise patients’ heat loss in the prehospital arena,...