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2021 ◽  
Vol 14 (2) ◽  
pp. 1047-1073
Author(s):  
Maria V. Makarova ◽  
Carlos Alberti ◽  
Dmitry V. Ionov ◽  
Frank Hase ◽  
Stefani C. Foka ◽  
...  

Abstract. Global climate change is one of the most important scientific, societal and economic contemporary challenges. Fundamental understanding of the major processes driving climate change is the key problem which is to be solved not only on a global but also on a regional scale. The accuracy of regional climate modelling depends on a number of factors. One of these factors is the adequate and comprehensive information on the anthropogenic impact which is highest in industrial regions and areas with dense population – modern megacities. Megacities are not only “heat islands”, but also significant sources of emissions of various substances into the atmosphere, including greenhouse and reactive gases. In 2019, the mobile experiment EMME (Emission Monitoring Mobile Experiment) was conducted within the St. Petersburg agglomeration (Russia) aiming to estimate the emission intensity of greenhouse (CO2, CH4) and reactive (CO, NOx) gases for St. Petersburg, which is the largest northern megacity. St. Petersburg State University (Russia), Karlsruhe Institute of Technology (Germany) and the University of Bremen (Germany) jointly ran this experiment. The core instruments of the campaign were two portable Bruker EM27/SUN Fourier transform infrared (FTIR) spectrometers which were used for ground-based remote sensing measurements of the total column amount of CO2, CH4 and CO at upwind and downwind locations on opposite sides of the city. The NO2 tropospheric column amount was observed along a circular highway around the city by continuous mobile measurements of scattered solar visible radiation with an OceanOptics HR4000 spectrometer using the differential optical absorption spectroscopy (DOAS) technique. Simultaneously, air samples were collected in air bags for subsequent laboratory analysis. The air samples were taken at the locations of FTIR observations at the ground level and also at altitudes of about 100 m when air bags were lifted by a kite (in case of suitable landscape and favourable wind conditions). The entire campaign consisted of 11 mostly cloudless days of measurements in March–April 2019. Planning of measurements for each day included the determination of optimal location for FTIR spectrometers based on weather forecasts, combined with the numerical modelling of the pollution transport in the megacity area. The real-time corrections of the FTIR operation sites were performed depending on the actual evolution of the megacity NOx plume as detected by the mobile DOAS observations. The estimates of the St. Petersburg emission intensities for the considered greenhouse and reactive gases were obtained by coupling a box model and the results of the EMME observational campaign using the mass balance approach. The CO2 emission flux for St. Petersburg as an area source was estimated to be 89 ± 28 ktkm-2yr-1, which is 2 times higher than the corresponding value in the EDGAR database. The experiment revealed the CH4 emission flux of 135 ± 68 tkm-2yr-1, which is about 1 order of magnitude greater than the value reported by the official inventories of St. Petersburg emissions (∼ 25 tkm-2yr-1 for 2017). At the same time, for the urban territory of St. Petersburg, both the EMME experiment and the official inventories for 2017 give similar results for the CO anthropogenic flux (251 ± 104 tkm-2yr-1 vs. 410 tkm-2yr-1) and for the NOx anthropogenic flux (66 ± 28 tkm-2yr-1 vs. 69 tkm-2yr-1).


Author(s):  
Sheng Dong ◽  
Yun-Seok Kang ◽  
John Bolte ◽  
Jason Stammen ◽  
Kevin Moorhouse

Abstract Motor vehicle crashes can produce serious head or brain injuries due to contact with interior vehicle structures. It has been found through both field data analysis and experimental testing that many of these brain injuries occur in oblique crashes, even with the deployment of air bags. Research has determined that rotational head velocity is strongly correlated to the risk of brain injury through metrics such as Brain Rotational Injury Criteria (BrIC). The severity of rotational head motion could be related to the friction force developed during contact between the head and air bags. Although crash test dummy head skins are designed with appropriate mass properties and anthropometry as well as material type and thickness to emulate the proper impact response of the human head, it is not known whether they accurately represent the frictional properties of human skin during air bag interaction. This study experimentally characterized the friction coefficient between human skin and air bag fabrics using a pin-on-disc tribometer. Skin samples were harvested from different locations (forehead, cheeks, chin) from specimens of post-mortem human subjects (PMHS). Fabric samples were cut from six different air bags spanning various vehicle manufacturers and interior mounting locations. For comparison, four types of dummy head skin samples were also tested against the air bag samples. Friction was measured between different skinair bag material combinations at various linear velocities and normal forces. It was determined that the difference between human and dummy skin friction with the air bag samples varied significantly among different air bags; however, the effect of linear speed, normal force, and human skin sample harvesting location on friction coefficient is negligible. Except for one air bag fabric, the friction coefficients of the dummy skin are higher than those quantified for human skin.


2020 ◽  
Author(s):  
Kyle Kercher ◽  
Jesse A. Steinfeldt ◽  
Jonathan T. Macy ◽  
Keisuke Ejima ◽  
Keisuke Kawata

ABSTRACTPurposeUSA Football established five levels of contact (LOC) to guide the intensity of high school football practices. However, it remains unclear whether head impact exposure differs by LOC. The purpose of this study was to examine head impact frequency and magnitude by LOC in the overall sample and three position groups.MethodsThis longitudinal observational study included 24 high school football players during all practices and games in the 2019 season. Players wore a sensor-installed mouthguard that monitored head impact frequency, peak linear acceleration (PLA), and rotational head acceleration (PRA). Practice/game drills were filmed and categorized into 5 LOCs (air, bags, control, thud, live), and head impact data were assigned into 5 LOCs. Player position was categorized into linemen, hybrid, and skill.ResultsA total of 6016 head impacts were recorded during 5 LOCs throughout the season. In the overall sample, total number of impacts, sum of PLA, and PRA per player increased in an incremental manner (air<bags<control<thud<live), with the most head impacts in live (113.7±17.8 hits/player) and the least head impacts in air (7.7±1.9 hits/player). The linemen and hybrid groups had consistently higher impact exposure than the skill group. Average head impact magnitudes by position group were higher during live drills (PLA (41.0-45.9g) and PRA (3.3-4.6 krad/s2) per head impact), whereas other LOCs had lower magnitudes (PLA (18.2-23.2g) and PRA (1.6-2.3krad/s2) per impact).ConclusionOur data suggest that LOC may influence cumulative head impact exposure in high school football, with players incurring frequent head impacts during live, thud, and control. The data indicate the importance of considering LOCs to refine practice guidelines and policies to minimize head impact burden in high school football athletes.


Author(s):  
Enrique Contreras-Calderón ◽  
Iván Alcalá-Barojas ◽  
Jorge Salvador Valdez-Martínez ◽  
Alberto Miguel Beltrán-Escobar

The automotive industry has always been concerned with improving day by day all of its vehicle models, developing more comfortable systems for its users, such as rear cameras, automatic parking systems, collision detection, air bags, etc. However, it has neglected certain aspects like the replacement of tires when having a puncture, using devices that have not changed in a long time. We present the design of a protoype coupled to a bottle-type hydraulic jack to elevate automotive vehicles, replacing the mechanical energy provided by the human with electrical energy of direct current provided by the car’s battery. The prototype consists of a 12 V gear motor that moves a gear train mechanism to activate a crank that will be coupled to the jack to produce the lifting.


2018 ◽  
Vol 58 (4) ◽  
pp. 210-215 ◽  
Author(s):  
Siobhan O’Donovan ◽  
Corinna van den Huevel ◽  
Matthew Baldock ◽  
Roger W Byard

Motor-vehicle collisions are the leading cause of unintentional injury and death in children in many parts of the world, including Europe, North America and Australia. The number of fatal collisions has decreased considerably in countries where safety measures such as child restraints, seat belts and air bags have been introduced, providing protection for children within vehicles, although it is recognised that there have been concomitant improvements in emergency responses and techniques, and in hospital treatments. Helmets and changes in external vehicle designs have been implemented to protect paediatric pedestrians and cyclists. However, despite the development of safety guidelines and technologies, injuries still occur. This paper provides an overview of the role of motor-vehicle collisions in paediatric morbidity and mortality to analyse the nature and aetiology of common fatal and non-fatal injuries in children that may present for forensic assessment as passengers, pedestrians or cyclists.


2018 ◽  
Vol 183 ◽  
pp. 04009 ◽  
Author(s):  
Krzysztof Mielczarek ◽  
Krzysztof Knop

In the chapter was presented enterprise producing air bags. described. Toyota’s management principles by Jeffrey Liker were pointed out, which refers to production process (second). An innovative BOST questionnaire survey was characterized as a tool for transformation of Toyota’s management principles into questions. Survey and research method determined as BOST (the name of the is an acronym created from the first two letters of the name and surname of his creator i.e. Stanislaw Borkowski, professor of technical and economic sciences, the acronym is legally protected). Results of the questionary were introduced. It was made an analysis in the range of the principle 2 of Toyota. It was shown analysis of respondent’s characteristics. Next structure of assessments was determined and some statistical graphs were built.


REAKTOR ◽  
2017 ◽  
Vol 9 (2) ◽  
pp. 20
Author(s):  
J. P. Sitompul

The use of hydrazine,N2H4 becomes very broad nowadays, in the production of polymer such as automobile air bags, in pharmacy, and in the water treatment for oxygen scavenge. Three commercial processes are available for hydrazine production , i.e. via Rasching-Olin, Ketazin, and Urea process. The operating condition for the later process is very mild compared to with the other two processes and hence requires simple processing equipments. This paper concerns with the kinetic study on production and on the effect of deactivator/ inhibitor during hydrazine bench-scale production via  Urea process. Operating condition are at 1 bar and at temperature range 5-100 0C. The yield of the hydrazine and its concentration with varying reactants, NaOH, hypochlorite, and urea during the cource of reaction are presented. Futher, the effect of gelatin as the deactivator toward hydrazine yield is futher examined. A kinetic model is proposed and used to predict yield of hydrazine. The predicted yield is in close agreement with the experimental yield.Keywords : hydrazine, bench-scale production, kinetic model, oxygen scavenger, inhibitor, geltine


2015 ◽  
Vol 9 (3) ◽  
pp. 86
Author(s):  
Tharcisio A. Caldeira ◽  
Andréia A. Albino ◽  
Jorge Ferreira Brantes ◽  
T. Diana L. Van Aduard de Macedo-Soares
Keyword(s):  
Air Bags ◽  

Este artigo investigou a aversão à traição nos consumidores de produtos de segurança, propondo uma extensão ao trabalho desenvolvido por Gershoff e Koehler (2011). A literatura investigada discute o processo de tomada de decisão diante de condições incertas, a aversão ao risco e a aversão à traição. Foram realizados três experimentos com 525 universitários que escolheram entre dois carros idênticos equipados com diferentes air bags. Dentre os participantes, alguns eram aleatoriamente expostos à possibilidade de falha do air bag. O primeiro experimento investigou se os tipos de traição influenciavam as escolhas. O segundo experimento investigou se havia diferenças nas escolhas de acordo com o destinatário do produto. O terceiro experimento investigou se a exposição a campanhas de direção defensiva interferia na escolha. Após a realização de testes ANOVA, os resultados evidenciaram a existência da aversão à traição quando os indivíduos eram expostos à informação da possibilidade de traição de um produto de segurança. 


Author(s):  
M. Shahinpoor ◽  
H. Asanuma

Presented is an initial discussion on dynamic simulation of tsunami air bag deployment in connection with a number of smart inflatable and deployable structures, called tsunami air bags (TAB) that can be rather quickly set up and strongly anchored to the ocean floor to withstand the impact of a tsunami wave and thus protect the buildings and structures on shore. These dedicated inflatable smart structures are designed such that upon tsunami impact they can perform two smart deployment tasks. The first one is for the structure to deploy in the form of a porous structure containing internal folds and pockets and reconfigure due to tsunami impact to perform energy absorption by forcing the tsunami waves to pass through the porous inflatable structure forcing the tsunami waves to lose kinetic energy due to viscous drag and pressurizing the TABs. The second task is related to a special de sign of the inflatable structure that causes it to deploy to either further vertically rise or become a hollow inflatable dam upon the tsunami impact. In these endeavors a wave generation channel was designed and constructed to perform experiments and to simulate tsunami wave impacts on inflatable structures deploying from an underwater location. The initial observation indicates that TABs have a great potential to mitigate tsunami impacts.


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