16,910 results match your criteria Aircraft Engineering And Aerospace Technology[Journal]

Toward practical stratospheric aerosol albedo modification: Solar-powered lofting.

Sci Adv 2021 May 14;7(20). Epub 2021 May 14.

Institute for Environmental and Climate Research, Jinan University, Guangzhou, China.

Many climate intervention (CI) methods have been proposed to offset greenhouse gas-induced global warming, but the practicalities regarding implementation have not received sufficient attention. Stratospheric aerosol injection (SAI) involves introducing large amounts of CI material well within the stratosphere to enhance the aerosol loading, thereby increasing reflection of solar radiation. We explore a delivery method termed solar-powered lofting (SPL) that uses solar energy to loft CI material injected at lower altitudes accessible by conventional aircraft. Read More

View Article and Full-Text PDF

Finite-time control of delay switched systems via input anti-bump switching.

ISA Trans 2021 May 8. Epub 2021 May 8.

College of Marine Electrical Engineering, Dalian Maritime University, Dalian, 116026, China. Electronic address:

This article devotes to the finite-time (FT) input anti-bump switching control (SC) issue for a kind of delay switched systems (DSSs). Our objective is to carry the FT control while bringing down possible large jumps in the control input. First, a formulation of the alleviation for the control signal jumps is given. Read More

View Article and Full-Text PDF

Risk of cardiovascular mortality, stroke and coronary heart mortality associated with aircraft noise around Congonhas airport, São Paulo, Brazil: a small-area study.

Environ Health 2021 May 13;20(1):59. Epub 2021 May 13.

UK Small Area Health Statistics Unit (SAHSU), Department of Epidemiology & Biostatistics, School of Public Health, Imperial College London, London, UK.

Background: Noise pollution is increasingly recognised as a public health hazard, yet limited evidence is available from low- and middle-income countries (LMIC), particularly for specific sources. Here, we investigated the association between day-night average (L) aircraft noise and the risk of death due to cardiovascular disease (CVD), stroke and coronary heart disease (CHD) at small-area level around São Paulo's Congonhas airport, Brazil during the period 2011-2016.

Methods: We selected 3259 census tracts across 16 districts partially or entirely exposed to ≥50 dB aircraft noise levels around the Congonhas airport, using pre-modelled 5 dB L noise  bands (≤50 dB to > 65 dB). Read More

View Article and Full-Text PDF

Hyperbaric oxygen for decompression sickness.

Undersea Hyperb Med 2021 Second Quarter;48(2):195-203

Departments of Anesthesiology and Medicine, Center for Hyperbaric Medicine and Environmental Physiology, Duke University, North Carolina U.S.

Decompression sickness (DCS, "bends") is caused by formation of bubbles in tissues and/or blood when the sum of dissolved gas pressures exceeds ambient pressure (supersaturation). This may occur when ambient pressure is reduced during any of the following: ascent from a dive; depressurization of a hyperbaric chamber; rapid ascent to altitude in an unpressurized aircraft or hypobaric chamber; loss of cabin pressure in an aircraft; and during space walks. Read More

View Article and Full-Text PDF

Thermal transport investigation in AA7072 and AA7075 aluminum alloys nanomaterials based radiative nanofluids by considering the multiple physical flow conditions.

Sci Rep 2021 May 10;11(1):9837. Epub 2021 May 10.

Department of Mathematics, College of Arts and Sciences, Prince Sattam Bin Abdulaziz University, Wadi Aldawaser, 11991, Saudi Arabia.

Now a day's variety of nanomaterials is available, among these Aluminum Alloys AA7072 and AA705 are significant due to their thermal, physical and mechanical characteristics. These extensively used in manufacturing of spacecraft, aircraft parts and building testing. Keeping in view the significance of nanoliquids, the analysis of methanol suspended by AA7072 and AA7075 alloys under the multiple physical flow conditions is reported. Read More

View Article and Full-Text PDF

A new analytical approach for preconcentration, separation and determination of Pb(II) and Cd(II) in real samples using a new adsorbent: Synthesis, characterization and application.

Food Chem 2021 Apr 22;359:129923. Epub 2021 Apr 22.

Department of Chemistry, Sivas Cumhuriyet University, Sivas, Turkey.

A green and efficient analytical approach was reported for simultaneous preconcentration, and separation of Pb(II) and Cd(II) in water, vegetables, and barbecue samples by dispersive solid-phase microextraction prior to their determination using flame atomic absorption spectrometry. A new poly-3-hydroxy butyrate-polyvinyl triethyl ammonium chloride comb-type amphiphilic cationic block copolymer (PHBvbNCl) was synthesized and characterized. Main variables such as pH, sorbent amount, adsorption time, eluent type, desorption time, and sample volume were optimized. Read More

View Article and Full-Text PDF

Correlation Between Physiological and Performance-Based Metrics to Estimate Pilots' Cognitive Workload.

Front Psychol 2021 20;12:555446. Epub 2021 Apr 20.

I3D Lab, Centre for Product Design and Manufacturing, Indian Institute of Science (IISc), Bengaluru, India.

This paper discusses the utilization of pilots' physiological indications such as electroencephalographic (EEG) signals, ocular parameters, and pilot performance-based quantitative metrics to estimate cognitive workload. The study aims to derive a non-invasive technique to estimate pilot's cognitive workload and study their correlation with standard physiological parameters. Initially, we conducted a set of user trials using well-established psychometric tests for evaluating the effectiveness of pupil and gaze-based ocular metrics for estimating cognitive workload at different levels of task difficulty and lighting conditions. Read More

View Article and Full-Text PDF

Preliminary user centred evaluation of regional aircraft cabin interiors in virtual reality.

Sci Rep 2021 May 6;11(1):9662. Epub 2021 May 6.

Center for Studies and Research in Cognitive Neuroscience, Department of Psychology, University of Bologna, Cesena, Italy.

The main aim of the CASTLE (Cabin System Design Towards Passenger Wellbeing) European project is to deliver innovative interiors solutions that maximize the comfort and wellbeing of passengers in the next future. To achieve such objective, an effective HCD (Human Centred Design) approach has been employed to derive a Human Response Model based on a holistic assessment of comfort. The overall methodology has been conceived to provide different tools and methods to collect data on the impact that the design of each cabin item has on the user from the earliest design stages. Read More

View Article and Full-Text PDF

Theoretical and experimental insights into the effects of halogen composition on the thermal decomposition details, as well as the fire-suppressing mechanism and performance of CFCX[double bond, length as m-dash]CH (X = F, Cl, Br).

Phys Chem Chem Phys 2021 May 5. Epub 2021 May 5.

Center for Aircraft Fire and Emergency, Department of Safety Engineering, Civil Aviation University of China, China.

The mechanism of thermal decomposition and fire suppression, and the fire-extinguishing performance of HFO-1234yf, HCFO-1233xf and 2-BTP agents were investigated by using both experimental and theoretical methods. The different halogen atoms connected with the middle carbon atom result in the varied strength of C-X (X = F, Cl, Br) bonds, and thus different thermal stability of these agents, which could further affect the pyrolysis mechanism/products and the fire-extinguishing mechanism/performance of these agents. Owing to the generation of CF3˙, Cl˙ and Br˙ radicals, as well as some unsaturated small molecules produced by their pyrolysis, the HFO-1234yf, HCFO-1233xf and 2-BTP agents have minimum extinguishing concentrations (MECs) of 9. Read More

View Article and Full-Text PDF

Cellular and Virtualization Technologies for UAVs: An Experimental Perspective.

Sensors (Basel) 2021 Apr 29;21(9). Epub 2021 Apr 29.

Telefónica I+D, Distrito Telefónica, Ronda de la Comunicación s/n, 28050 Madrid, Spain.

The Unmanned Aircraft System (UAS) ecosystem is exponentially growing in both recreational and professional fields to provide novel services and applications to consumers from multiple engineering fields. However, this technology has only scraped the surface of its potential, especially in those cases that require fast reaction times. Accordingly, the UAS Traffic Management (UTM) project aims at efficiently managing the air traffic for Unmanned Aerial Vehicle (UAV) operations, including those cases where UAVs might be remotely managed from a completely different geographical location. Read More

View Article and Full-Text PDF

Quantitative Assessment of the Entry through Mechanical Transport in Aircraft of Rift Valley Fever Virus-Infected Mosquitoes into Previously Unaffected Areas.

Pathogens 2021 Apr 30;10(5). Epub 2021 Apr 30.

Research Unit of Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULiège), Fundamental and Applied Research for Animals and Health (FARAH) Center, Faculty of Veterinary Medicine, University of Liege, 4000 Liège, Belgium.

(1): Rift Valley Fever (RVF) is a zoonotic disease of significant international health concern and considered as an emerging risk to Europe, where no RVF outbreaks in humans or animals have been reported so far. (2): Using a stochastic approach, we estimated the risk of RVF virus (RVFV) introduction during the period of May to October (the period when mosquito populations, including RVFV potential vectors, are present in European countries), into previously unaffected areas (e.g. Read More

View Article and Full-Text PDF

Intraoperative and postoperative complications in colorectal procedures: the role of continuous updating in medicine.

Minerva Surg 2021 May 4. Epub 2021 May 4.

IRCAD, Research Institute against Digestive Cancer, Strasbourg, France.

Accepting surgical complications, especially those related to the learning curve, as unavoidable events in colorectal procedures, is like accepting to fly onboard an aircraft with a 10 to 20% chance of not arriving at final destination. Under this condition, it is very likely that the aviation industry and the concurrent reshaping of the world and of our lives would have not been possible in the absence of high reliability and reproducibility of safe flights. It's hard to imagine surgery without any intraoperative and/or postoperative complications. Read More

View Article and Full-Text PDF

Microstates in complex and dynamical environments: Unraveling situational awareness in critical helicopter landing maneuvers.

Hum Brain Mapp 2021 May 4. Epub 2021 May 4.

Hospital Israelita Albert Einstein, São Paulo, Brazil.

Understanding decision-making in complex and dynamic environments is relevant for designing strategies targeting safety improvements and error rate reductions. However, studies evaluating brain dynamics in realistic situations are scarce in the literature. Given the evidence that specific microstates may be associated with perception and attention, in this work we explored for the first time the application of the microstate model in an ecological, dynamic and complex scenario. Read More

View Article and Full-Text PDF

Evidence for nonlinear reflections in shock-containing noise near high-performance military aircraft.

J Acoust Soc Am 2021 Apr;149(4):2403

Blue Ridge Research and Consulting, LLC, 29 North Market Street, Suite 700, Asheville, North Carolina 28801, USA.

Skewness values for the pressure time derivative are greater at ground-based measurements near a tactical aircraft than they are at nearby off-ground locations. A possible explanation for this phenomenon is the occurrence of nonlinear, irregular shock reflections at the ground. Propagation angle, source location, and corresponding angle of incidence relative to the ground are estimated using a two-point cross correlation of windowed shock events. Read More

View Article and Full-Text PDF

Synergistic aircraft and ground observations of transported wildfire smoke and its impact on air quality in New York City during the summer 2018 LISTOS campaign.

Sci Total Environ 2021 Jun 3;773:145030. Epub 2021 Feb 3.

City College of New York, New York, NY 10031, USA; NOAA - Cooperative Science Center for Earth System Sciences and Remote Sensing Technologies, New York, NY 10031, USA.

Air pollution associated with wildfire smoke transport during the summer can significantly affect ozone (O) and particulate matter (PM) concentrations, even in heavily populated areas like New York City (NYC). Here, we use observations from aircraft, ground-based lidar, in-situ analyzers and satellite to study and assess wildfire smoke transport, vertical distribution, optical properties, and potential impact on air quality in the NYC urban and coastal areas during the summer 2018 Long Island Sound Tropospheric Ozone Study (LISTOS). We investigate an episode of dense smoke transported and mixed into the planetary boundary layer (PBL) on August 15-17, 2018. Read More

View Article and Full-Text PDF

Silica Aerogels with Self-Reinforced Microstructure for Bioinspired Hydrogels.

Langmuir 2021 May 3. Epub 2021 May 3.

Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China.

Aerogel is a kind of high-performance lightweight open-porous solids with ultralow density, high specific surface area, and broad application in many emerging fields including biotechnology, energy, environment, aerospace, etc. A giant challenge remains in preventing of the hydrophilic aerogel framework shrinkage when replacing of solvent with air in its extremely abundant nanosized pores during its fabrication process in ambient conditions. In this work, started from a linear polymeric precursor with further condensation reaction, superhydrophilic silica aerogels with self-reinforced microstructure and the least volume shrinkage have been successfully obtained via ambient pressure drying process without use of any additives in the presence of a low surface tension solvent. Read More

View Article and Full-Text PDF

Insight into ozone profile climatology over northeast China from aircraft measurement and numerical simulation.

Sci Total Environ 2021 Apr 24;785:147308. Epub 2021 Apr 24.

Joint International Research Laboratory of Atmospheric and Earth System Sciences (JirLATEST), School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China; Jiangsu Province Collaborative Innovation Center of Climate Change, Nanjing, China. Electronic address:

Tropospheric ozone is a major pollutant that can harm human health, animals and plants. With a rapid development in Northeast China, ozone pollution has become an increasingly serious environmental challenge. To study the ozone distribution and the potential sources of ozone precursors in Northeast China, we analyzed vertical ozone profiles from the In-service Aircraft for a Global Observing System (IAGOS) in 2012-2014 and provided the climatological vertical structure of tropospheric ozone over Shenyang. Read More

View Article and Full-Text PDF

Electrochemical Surface Structuring for Strong SMA Wire-Polymer Interface Adhesion.

ACS Appl Mater Interfaces 2021 May 30;13(18):21924-21935. Epub 2021 Apr 30.

Functional Nanomaterials, Institute for Materials Science, Faculty of Engineering, Kiel University, Kaiserstraße 2, D-24143 Kiel, Germany.

Active hybrid composites represent a novel class of smart materials used to design morphing surfaces, opening up new applications in the aircraft and automotive industries. The bending of the active hybrid composite is induced by the contraction of electrically activated shape memory alloy (SMA) wires, which are placed with an offset to the neutral axis of the composite. Therefore, the adhesion strength between the SMA wire and the surrounding polymer matrix is crucial to the load transfer and the functionality of the composite. Read More

View Article and Full-Text PDF

Ablation of lysozyme M-positive cells prevents aircraft noise-induced vascular damage without improving cerebral side effects.

Basic Res Cardiol 2021 Apr 30;116(1):31. Epub 2021 Apr 30.

Department of Cardiology, Cardiology I-Laboratory of Molecular Cardiology, University Medical Center of the Johannes Gutenberg-University, Building 605, Langenbeckstr. 1, 55131, Mainz, Germany.

Aircraft noise induces vascular and cerebral inflammation and oxidative stress causing hypertension and cardiovascular/cerebral dysfunction. With the present studies, we sought to determine the role of myeloid cells in the vascular vs. cerebral consequences of exposure to aircraft noise. Read More

View Article and Full-Text PDF

In-flight Medical Emergencies.

Am Fam Physician 2021 May;103(9):547-552

Christus Mother Frances Hospital, Sulphur Springs, TX, USA.

In 2018, approximately 2.8 million passengers flew in and out of U.S. Read More

View Article and Full-Text PDF

Extreme oxidant amounts produced by lightning in storm clouds.

Science 2021 May 29;372(6543):711-715. Epub 2021 Apr 29.

Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA.

Lightning increases the atmosphere's ability to cleanse itself by producing nitric oxide (NO), leading to atmospheric chemistry that forms ozone (O) and the atmosphere's primary oxidant, the hydroxyl radical (OH). Our analysis of a 2012 airborne study of deep convection and chemistry demonstrates that lightning also directly generates the oxidants OH and the hydroperoxyl radical (HO). Extreme amounts of OH and HO were discovered and linked to visible flashes occurring in front of the aircraft and to subvisible discharges in electrified anvil regions. Read More

View Article and Full-Text PDF

Short-Term Annoyance Due to Night-Time Road, Railway, and Air Traffic Noise: Role of the Noise Source, the Acoustical Metric, and Non-Acoustical Factors.

Int J Environ Res Public Health 2021 Apr 27;18(9). Epub 2021 Apr 27.

German Aerospace Center (DLR), Institute of Aerospace Medicine, 51170 Cologne, Germany.

Field studies on traffic noise-induced annoyance have predominantly used estimated outside noise levels. We intended to complement existing knowledge with exposure-response relationships that are based on precise indoor noise measurements. Acoustic recordings inside the bedrooms of nightly road traffic and annoyance ratings in the following morning were obtained from 40 suburban residents (mean age 29. Read More

View Article and Full-Text PDF

A Particle Filtering Approach for Fault Detection and Isolation of UAV IMU Sensors: Design, Implementation and Sensitivity Analysis.

Sensors (Basel) 2021 Apr 28;21(9). Epub 2021 Apr 28.

Dipartimento di Ingegneria dell'Informazione, Delle Infrastrutture e dell'Energia Sostenibile, Universitá degli Studi "Mediterranea" di Reggio Calabria, 89122 Reggio Calabria, Italy.

Sensor fault detection and isolation (SFDI) is a fundamental topic in unmanned aerial vehicle (UAV) development, where attitude estimation plays a key role in flight control systems and its accuracy is crucial for UAV reliability. In commercial drones with low maximum take-off weights, typical redundant architectures, based on triplex, can represent a strong limitation in UAV payload capabilities. This paper proposes an FDI algorithm for low-cost multi-rotor drones equipped with duplex sensor architecture. Read More

View Article and Full-Text PDF

Identification of Pilots' Fatigue Status Based on Electrocardiogram Signals.

Sensors (Basel) 2021 Apr 25;21(9). Epub 2021 Apr 25.

College of General Aviation and Flight, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China.

Fatigue is an important factor affecting modern flight safety. It can easily lead to a decline in pilots' operational ability, misjudgments, and flight illusions. Moreover, it can even trigger serious flight accidents. Read More

View Article and Full-Text PDF

Noise-Induced Vascular Dysfunction, Oxidative Stress, and Inflammation Are Improved by Pharmacological Modulation of the NRF2/HO-1 Axis.

Antioxidants (Basel) 2021 Apr 19;10(4). Epub 2021 Apr 19.

Department of Cardiology, Cardiology I, University Medical Center of the Johannes Gutenberg-University, Langenbeckstraße 1, 55131 Mainz, Germany.

Vascular oxidative stress, inflammation, and subsequent endothelial dysfunction are consequences of traditional cardiovascular risk factors, all of which contribute to cardiovascular disease. Environmental stressors, such as traffic noise and air pollution, may also facilitate the development and progression of cardiovascular and metabolic diseases. In our previous studies, we investigated the influence of aircraft noise exposure on molecular mechanisms, identifying oxidative stress and inflammation as central players in mediating vascular function. Read More

View Article and Full-Text PDF

How Does a Community Respond to Changes in Aircraft Noise? A Comparison of Two Surveys Conducted 11 Years Apart in Ho Chi Minh City.

Int J Environ Res Public Health 2021 Apr 19;18(8). Epub 2021 Apr 19.

Department of Architecture, National Institute of Technology, Ishikawa College, Tsubata, Kahoku-gun, Ishikawa 929-0932, Japan.

There have been many arguments about findings of an increase in noise annoyance over time and a recommendation of stricter limits on aircraft noise levels to protect the health of residents around airports. It is crucial to examine if the established exposure-response relationship is suitable for designing future aircraft noise regulations. This study was focused on identifying changes in response to noise over time by comparing community responses from two surveys conducted in 2008 and 2019 at Tân Sơn Nhất (TSN) international airport. Read More

View Article and Full-Text PDF

Detection and Quantification of Delamination Failures in Marine Composite Bulkheads via Vibration Energy Variations.

Sensors (Basel) 2021 Apr 17;21(8). Epub 2021 Apr 17.

Técnicas y Servicios de Ingeniería S.L., Avda. Pio XII, 44, 28016 Madrid, Spain.

This paper proposes a new vibration-based structural health monitoring method for the identification of delamination defects in composite bulkheads used in small-length fiber-based ships. The core of this work is to find out if the variations of vibration energy can be efficiently used as a key performance indicator for the detection and quantification of delamination defects in marine composite bulkheads. For this purpose, the changes of vibrational energy exerted by delamination defects in sandwich and monolithic composite panel bulkheads with different types of delamination phenomenon are investigated using a non-destructive test. Read More

View Article and Full-Text PDF

A Review of Corrosion in Aircraft Structures and Graphene-Based Sensors for Advanced Corrosion Monitoring.

Sensors (Basel) 2021 Apr 21;21(9). Epub 2021 Apr 21.

Department of Electronics Engineering, Carleton University, Ottawa, ON K1S 5B6, Canada.

Corrosion is an ever-present phenomena of material deterioration that affects all metal structures. Timely and accurate detection of corrosion is required for structural maintenance and effective management of structural components during their life cycle. The usage of aircraft materials has been primarily driven by the need for lighter, stronger, and more robust metal alloys, rather than mitigation of corrosion. Read More

View Article and Full-Text PDF

Spider Web-Inspired Lightweight Membrane-Type Acoustic Metamaterials for Broadband Low-Frequency Sound Isolation.

Polymers (Basel) 2021 Apr 2;13(7). Epub 2021 Apr 2.

School of Aeronautics, Northwestern Polytechnical University, Xi'an 710072, China.

Membrane-type acoustic metamaterial (MAM) has exhibited superior sound isolation properties, as well as thin and light characteristics. However, the anti-resonance modes of traditional MAMs are generated intermittently in a wide frequency range causing discontinuities in the anti-resonance modes. Achieving broadband low-frequency sound attenuation with lightweight MAM design is still a pivotal research aspect. Read More

View Article and Full-Text PDF

Experiment and Simulation Research on the Fatigue Wear of Aircraft Tire Tread Rubber.

Polymers (Basel) 2021 Apr 2;13(7). Epub 2021 Apr 2.

Center for Rubber Composite Materials and Structures, Harbin Institute of Technology, Weihai 264209, China.

The road surface and the tread pattern structures directly affect the wear performance of aircraft tire, especially for lateral sliding conditions. In this paper, wear tests of tread block with different draft angles and root radiuses, different interfaces, and different slip angles were carried out, and combined with the simulation, the effects of tread groove structure and slip angle on the wear mechanism were analyzed. Results indicated that the influences of draft angle were greater than the root radius; the wear geometry of the tread block decreased when the draft angle increased in the range of 0° to 15°, but for the root radius, the wear geometry of each sample was similar to a strip shape. Read More

View Article and Full-Text PDF