Journal articles on the topic 'Open air factor'
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Hobday, R. A. "The open-air factor and infection control." Journal of Hospital Infection 103, no. 1 (September 2019): e23-e24. http://dx.doi.org/10.1016/j.jhin.2019.04.003.
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Cox, R. Anthony, Markus Ammann, John N. Crowley, Paul T. Griffiths, Hartmut Herrmann, Erik H. Hoffmann, Michael E. Jenkin, et al. "Opinion: The germicidal effect of ambient air (open-air factor) revisited." Atmospheric Chemistry and Physics 21, no. 17 (September 2, 2021): 13011–18. http://dx.doi.org/10.5194/acp-21-13011-2021.
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Abstract. The term open-air factor (OAF) was coined following microbiological research in the 1960s and 1970s which established that rural air had powerful germicidal properties and attributed this to Criegee intermediates formed in the reaction of ozone with alkenes. We have re-evaluated those early experiments applying the current state of knowledge of ozone–alkene reactions. Contrary to previous speculation, neither Criegee intermediates nor the HO radicals formed in their decomposition are directly responsible for the germicidal activity attributed to the OAF. We identify other potential candidates, which are formed in ozone–alkene reactions and have known (and likely) germicidal properties, but the compounds responsible for the OAF remain a mystery. There has been very little research into the OAF since the 1970s, and this effect seems to have been largely forgotten. In this opinion piece we remind the community of the germicidal open-air factor. Given the current global pandemic spread by an airborne pathogen, understanding the natural germicidal effects of ambient air, solving the mystery of the open-air factor and determining how this effect can be used to improve human welfare should be a high priority for the atmospheric science community.
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IINO, Akinaru, Kazuhiro KOGA, Kenji TSUKAMOTO, and Satoru ITO. "FACTOR ON AIR TEMPERATURE DISTRIBUTION ON OPEN TYPE PLATFORMS." Journal of Environmental Engineering (Transactions of AIJ) 70, no. 587 (2005): 37–44. http://dx.doi.org/10.3130/aije.70.37_1.
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BAILEY, ROGER, LOUISE FIELDING, ANDY YOUNG, and CHRIS GRIFFITH. "Effect of Ozone and Open Air Factor against Aerosolized Micrococcus luteus." Journal of Food Protection 70, no. 12 (December 1, 2007): 2769–73. http://dx.doi.org/10.4315/0362-028x-70.12.2769.
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Because of increased concerns over failures in cleaning, the role of bioaerosols, and the environmental and clinical persistence of pathogens, the evaluation of novel decontaminants is increasingly important. The bactericidal properties of open air factor (OAF; a collection of highly reactive chemical species) were identified in the 1970s; however, the potential practical applications of artificially generated OAF have been considered only recently. In this study, the effects of OAF against Micrococcus luteus were investigated. OAF was generated and distributed in a bioaerosol test chamber by delivery of monoterpenes into ozonated air (0.1 ppm) at concentrations of 2.0 (high), 0.75 (medium), or 0.3 (low) mgm−3 h−1. M. luteus was aerosolized, and the number of culturable survivors was determined after 2, 5, 10, 20, and 60 min. Culturable bacteria were enumerated by aerobic plate counts in all-glass impinger fluid. Data were analyzed for statistical significance using one- or two-way analyses of variance. When aerosolized bacteria were exposed to ozone alone (0.05, 0.1, and 2 ppm), a significant (up to 3-log) reduction was observed at all concentrations, and the effect was time dependent. When exposed to the cyclic monoterpene alone, there were no significant differences between test samples and controls. When exposed to OAF (high and medium concentrations in 0.1 ppm ozone) there were significant differences after 20 min. These reductions were significantly greater than those achieved with ozone alone at 0.1 ppm. OAF is potentially an effective antibacterial agent that can reduce the microbial load in air. Because the technology uses reaction compounds naturally found in the environment, risks to health may be lower than those associated with ozone or other gaseous treatments. However, this hypothesis needs further investigation.
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Gong, Myung Keun, Gun Woo Kim, and Myung Do Oh. "The Effect of Round Flow Path Discharger and Back Panel Open Ratio on a Performance of Open Refrigerating Showcase." International Journal of Air-Conditioning and Refrigeration 27, no. 03 (September 2019): 1950025. http://dx.doi.org/10.1142/s2010132519500251.
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Numerical study is conducted to confirm the effect of round flow path control and back panel open ratio on a performance of open refrigerating showcase in this study. The rounding control is applied to flow path of air discharger in various radii and the punched panel with various open ratios is applied to back panel of showcase. These structural changes have a significant impact on its aircurtain performance because both changes can affect flow pattern of showcase. To prove it, the two-dimensional steady simulation is performed using [Formula: see text]–[Formula: see text] turbulent model. The performance of showcase is assessed using entrainment factor which is a ratio between cooled air and ambient air at the suction of refrigerating part. As a result of simulation, the curved path at air discharger reduces the entrainment factor by a maximum 9% less than typical design. The curved flow path removes the dead zone at the honeycomb structure of discharger. In addition, it is found that there is an optimal back panel open ratio at the storage space of the showcase. When the back panel open ratio is 0%, the cooled air from the discharge is attached to the cold storage area because of the Cowanda effect. However, the Cowanda effect is eliminated when back panel open ratio increases. Results address that the entrainment factor remains almost the same at back panel open ratio 3.93% or more. Lastly, the simulation of showcase with product in cold storage area is conducted to confirm the structure changes effect on performance of real use showcase according to KS Standard.
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Sobko, Z. Z., N. M. Vozniuk, and O. A. Lykho. "Evolution of open air quality of urbanized territories under Covid-19 pandemic conditions." Ukrainian Journal of Ecology 10, no. 6 (December 10, 2020): 48–53. http://dx.doi.org/10.15421/2020_256.
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Current state of world affairs in 2020 during quarantine enforced due to COVID-19 pandemic is characterized, on the one hand, with economic recession, but on the other hand, also with improvement of ecological state of environment. Thus a unique opportunity came up to study processes of open air conditions formation in settlements in circumstances of restricted economic activity and limitations imposed on all kinds of transportation. This article presents results of research of trends of formation of open air quality of urbanized territories (using city of Rivne as an example) during quarantine enforced due to COVID-19 pandemic. It is determined that due to introduction of quarantine measures air quality has improved. So, during the quarantine as well as after relaxation of quarantine measures only concentration of formaldehyde in open air of Rivne city did exceed average daily MAC. Primary source of open air pollution in Rivne city is motor vehicles which comprise 79% of total amount of pollutant emissions. Main pollutants which influence formation of open air quality in the city are: dust, sulfur dioxide, nitrogen dioxide, hydrogen fluoride and formaldehyde. They exceeded average daily MAC by factor of 1.3 to 32. Complex air pollution index (CAPI) was equal to 5.4 during quarantine restrictions but grew to 5.7 when the restrictions were partially loosened. Thus, air pollution level was evaluated as "mild pollution". During the corresponding periods of 2019 this index was changing from 6.9 ("mild air pollution") to 7.7 ("polluted air") respectively. Open air pollution level is determined by a complex of constituents including pollutant emission amounts, their specifics and dependency on meteorological factors. Due to this aspect we have performed statistical examinations to determine dependency of open air pollutant concentrations on meteorological conditions using multiple correlation coefficients. Strong correlation was exhibited for nitrogen oxide, hydrogen chloride and ammonia: multiple correlation coefficients fall within 0.76-0.80 range; moderate correlation was seen for dust, sulfur dioxide, nitrogen dioxide, hydrogen disulphide, phenol and formaldehyde with multiple correlation coefficients varying in 0.51-0.70 range.
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Maddrell, SH. "Why are there no insects in the open sea?" Journal of Experimental Biology 201, no. 17 (September 1, 1998): 2461–64. http://dx.doi.org/10.1242/jeb.201.17.2461.
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The air-filled tracheal respiratory system of insects prevents them from diving deeply in water. It is argued that this is the major factor in preventing insects from colonizing the open sea: they cannot descend sufficiently deeply in the daytime to escape being eaten by fish.
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Gaspar, Pedro Dinis, L. C. Carrilho Gonçalves, and R. A. Pitarma. "Experimental analysis of the thermal entrainment factor of air curtains in vertical open display cabinets for different ambient air conditions." Applied Thermal Engineering 31, no. 5 (April 2011): 961–69. http://dx.doi.org/10.1016/j.applthermaleng.2010.11.020.
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Belyanovskaya, Elena, Kostyantyn Mikhaylovich Sukhyy, Yana Oleksandrivna Serhiienko, Mikhaylo Porfyryevich Sukhyy, G. Pustovoy, and Irina Valeriivna Sukha. "EXERGY ANALYSIS OF AN OPEN-MODE ADSORPTIVE HEAT STORAGE UNIT BASED ON COMPOSITE ADSORBENT ‘SILICA GEL – CRYSTALLINE HYDRATE’." Scientific Works 86, no. 1 (December 16, 2022): 51–56. http://dx.doi.org/10.15673/swonaft.v86i1.2403.
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Exergy analysis of an open-mode adsorptive heat storage unit has been performed when a composite ‘silica gel – crystalline hydrate’ used as an adsorbent. The crucial factors affecting the exergy efficiency factor are stated to be temperature and initial humidity of airflow supplied to the inlet of adsorbent layer, temperature of external air and methods of air flow humidification. Procedure of calculation of the operating characteristics of an open-mode adsorptive heat storage device was further developed. The suggested procedure involves determination of adsorption, specific adsorption heat and final airflow temperature, useful heat, heat inputs for operating heat storage device and its efficiency factor, then exergy recovered, exergy supplied and exergy efficiency are calculated. Exergy efficiency depends on characteristics of flow of humid air fanned into the adsorbent layer such as temperature and initial absolute humidity which strongly affect the adsorption and final airflow temperatures. Increase of initial temperature of the humid air leads to decreasing of the exergy efficiency. Maximal values of exergy efficiency are determined at the absolute humidity and temperatures of initial airflow within the ranges of 0.03 – 0.04 kg/m3 and 20 – 30ºC, respectively. These characteristics are corresponded to the maximal airflow temperatures after passing through the adsorbent layer which meet to the Sanitary Regulations. Dependence of exergy efficiency vs. external air temperature and initial airflow temperature is shown. The exergy efficiencies of the open-mode adsorptive heat storage unit with steam and ultrasonic humidification were compared. Ultrasonic humidification is shown to allow increasing the exergy efficiency by 7 % against steam humidification. The obtained results can be used when energy-efficient heat and ventilation systems for residential premises developed.
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Alifia, Lustyafa Inassani. "Karakteristik Masyarakat Desa Jatirejoyoso Mengenai Perilaku Buang Air Besar Sembarangan." CoMPHI Journal: Community Medicine and Public Health of Indonesia Journal 1, no. 2 (October 30, 2020): 84–91. http://dx.doi.org/10.37148/comphijournal.v1i2.10.
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Introduction: The proportion of open defecation behavior in Indonesia ranks second highest after India. Stop open defecation is the first pillar of the Community-Led Total Sanitation (CLTS) program as the main focus. Disposing feces that not eligible with sanitation requirements can cause soil pollution, the provision of clean water, and trigger the disease vectors. Aim of study: This study describes the characteristics of the people in Jatirejoyoso Village, Kepanjen District, Malang Regency regarding the ownership of healthy latrines, and the behavior of open defecation. This research sample was taken using a purposive sampling method of 46 households. Results and Discussion: The results showed 42 respondents (91.3%) understood the importance of healthy latrines. Meanwhile, 32 respondents (69.56%) behaved defecate in the river, and 14 (30.44%) of respondents conducted defecation in a neighbor's toilet. Residents who don’t have latrines because of the cost factor, as many as 40 respondents (86.96%), and the remaining 6 respondents due to lack of house land. 28 respondents (60.86%) experienced diarrhea within 1 year. All respondents (100%) claimed to have received information about BABS and PHBS from health workers in the village. Conclusion: The conclusion that can be drawn is the knowledge of the people of Jatirejoyoso Village about the importance of good healthy latrines, but the cost and land constraints are a factor for residents not to have private healthy latrines.
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Quratul Aini binti Udin, Asmia binti Kasim, Hanita binti Rassa, and Asma Ul Husna binti Abdul Nasir. "FACTORS THAT CONTRIBUTE TO AIR POLLUTION IN MALAYSIA." Malaysian Journal of Business and Economics (MJBE) 8, no. 2 (December 31, 2021): 43–58. http://dx.doi.org/10.51200/mjbe.vi.3662.
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In this study, the overall objective used is to identify the factors that contribute to air pollution in Malaysia. The objective chosen was to study further the factors that cause this pollution. The theory used in this study is conceptual. Not only that, the independent variables in this study are divided into 5 which are the open burning activities, industrial fuel burning and processes, transportation emissions, agriculture activities, and cigarettes smoke. While the dependent variable is the factor of air pollution. The type of sample used in this study is non-probability convenience sampling. This study was conducted in Klang Valley, Malaysia, the area that is often associated with this pollution. The total sample in the study was 55 respondents. In addition, the instrument used is a questionnaire to 55 respondents, consisting of 39 women and 16 men through the results of the questionnaire. The questionnaire was given in the form of Google Form which asked the respondents to give their responses or views on the causes of this air pollution. Not only that, the analysis method used in this study is a quantitative method and the findings of the study from the results of the questionnaire of 55 respondents showed that the main cause of air pollution is open burning in large forest areas. While the problem that causes less pollution is that cigarette smoke has nothing to do with the occurrence of air pollution through questionnaires.
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Клепиков, О. В., and С. А. Куролап. "Оценка уровня воздействия техногенных факторов при добыче и производстве гранитного щебня." ТЕНДЕНЦИИ РАЗВИТИЯ НАУКИ И ОБРАЗОВАНИЯ 70, no. 2 (2021): 122–24. http://dx.doi.org/10.18411/lj-02-2021-68.
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Using the example of Open Joint Stock Company «Pavlovskgranit», located in the Voronezh region, the level of impact of technogenic factors (air pollution and noise) during the extraction and production of crushed granite was estimated. It was established that 61 pollutants enter the atmospheric air from 134 sources of pollution. The main contribution to the total volume of emissions (1881.0 tons/year) is made by inorganic dust with a SiO2 content of 70-20% - 73.4%, sulfur dioxide - 9.8%, carbon monoxide - 114.3 tons/year. Blasting operations in open pits during the extraction of crushed granite are the leading production process that makes a significant contribution to the volume of emissions. At the same time, the remoteness of industrial sites from the territory of residential development, the presence of a sanitary protection zone, allows us to speak about the admissibility of the impact of concentrations of pollutants in the air and the noise factor at the border of the territory of the nearest residential development.
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Gudata, Daba. "Prevalence of ovine lung worm at Jucavm open air veterinary clinic, Southwest Ethiopia." International Journal of Research in Informative Science Application & Techniques (IJRISAT) 3, no. 4 (April 10, 2019): 51–67. http://dx.doi.org/10.46828/ijrisat.v3i4.82.
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A cross sectional study was conducted in Jimma university veterinary clinic, Ethiopia from April 2018 to May 2018. The objectives of study were to estimate the prevalence of lungworm infection and associated risk factors in sheep. Coproscopic examination was done by using a modified Baermann technique. Fecal samples were collected from randomly selected sheep of systematically chosen households. The study animals were composed of different breeds, age groups, sexes, management systems, and subjected to different health care conditions. Out of 384 sheep examined, 69 (17.9%) were found to be positive for one or more species of lungworm parasites. Dictyocaulus filaria (6.8%) was the predominant species of parasite identified followed by Muellerius capillaries (4.7%) Protostrongylus rufescens (2.6%) and mixed infection of D. filaria and M. capillaries (3.9%). There was statistically significant difference in prevalence of lungworm parasite (P<0.05)among the risk factor like body conditions of animals. Animals with young age, not dewormed, and managed under extensive production system were more infected with the parasites. On the other hand, the prevalence of the parasites among management, age groups, deworming history and sexes showed no statistically significant difference (P>0.05). Despite the smaller prevalence observed in this study, ovine lungworm is still a constraint to sheep in the area in different season of the year, and therefore, vigorous controlling strategy should be implemented to reduce the prevalence of infection.
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Nicholas, R., P. Dunton, A. Tatham, and L. Fielding. "The effect of ozone and open air factor on surface-attached and biofilm environmental Listeria monocytogenes." Journal of Applied Microbiology 115, no. 2 (June 3, 2013): 555–64. http://dx.doi.org/10.1111/jam.12239.
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Yu, Ke-zhi, Guo-liang Ding, and Tian-ji Chen. "A correlation model of thermal entrainment factor for air curtain in a vertical open display cabinet." Applied Thermal Engineering 29, no. 14-15 (October 2009): 2904–13. http://dx.doi.org/10.1016/j.applthermaleng.2009.02.016.
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Liyew, Erkihun Zelalem. "Effect of the Imperfection of Open-End Yarn (Thin, Thick, and Nep Place) on Air Permeability of Plain Woven Fabric." Journal of Engineering 2022 (February 18, 2022): 1–8. http://dx.doi.org/10.1155/2022/8710495.
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Wearing clothes is an intermediate channel by exchange of air released from human bodies and environments to bring breathing stability and to control body temperature. Air permeability is an expression describing the properties of a fabric that permit the passage of air through the fabric’s interstices. It has been found that there are many factors that can affect the air permeability of a fabric comfort. Several early studies of air permeability of different materials showed that different factors affect air permeability and breathability of fabrics, and some of them are imperfections of yarns (thick, thin, and nep place) which are introduced on the surface of the fabric that originated from the appearance of the yarn. In this experiment, the yarn and fabric samples are collected from five different spinning mills which have an identical warp yarn linear density of 20 Ne regardless of the weft linear density, and the fabric was constructed from those selected yarns by using the thread set of 28 ends per centimeter and 20 picks per centimeter. The experiment was conducted by measuring the imperfection of each code of yarn on USTER statistics and air permeability of the fabric with respect to the thin, thick, and nep place/km of the yarn and fabric cover. The impacts of each factor were analyzed, and the relationships of each parameter were stated on the graph. The results were discussed by using the design of the experiment by quadratic and linear models to the response of air permeability and fabric cover, respectively, and the results showed that there is a direct impact of thin, thick, and neps of the yarn on the ability of the fabric to permeate air.
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De Castro Ribeiro, Sergio, Marcio Peixoto De Sequeira Santos, and Carla Conceição Lana Fraga. "ANALYSIS OF REGIONAL AIRPORTS AS A FACTOR FOR DEVELOPMENT IN BRAZIL." Journal of Air Transport Studies 2, no. 2 (July 1, 2011): 49–73. http://dx.doi.org/10.38008/jats.v2i2.100.
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The establishment an open market policy in Brazil’s airline sector in the beginning of the 1990s has brought substantial changes to the country’s aviation regulatory framework. One effect of this liberalization has been a substantial decrease in the number of regional airports with regularly scheduled air service. This paper discusses both the internal and external factors that have directly affected the present scenario, based on a review of the literature. We first provide an overview of the evolution of the country’s airport industry and its management concerns, and then analyze the effect of the deregulation process on air travel and the social and economic changes this has brought to smaller cities, especially those in the northern region. The overall effect has been to weaken the country’s potential for national integration and political unity.
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Georgakis, C., M. Santamouris, and G. Kaisarlis. "The Vertical Stratification of Air Temperature in the Center of Athens." Journal of Applied Meteorology and Climatology 49, no. 6 (June 1, 2010): 1219–32. http://dx.doi.org/10.1175/2010jamc2290.1.
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Abstract The intraurban temperature variation in the center of Athens, Greece, was investigated in relation to urban geometry. This paper describes two main tasks: 1) Air temperature was recorded in the center of Athens and at the Meteorological Service Station at the University of Athens. Experimental data were collected through extensive monitoring at four different heights inside five different urban canyons in the center of Athens during the summer period. A measurement uncertainty analysis was carried out to estimate critical threshold values of air temperature below which differences were not significant. 2) The correlation between urban–suburban air temperature differences was assessed, using the geometrical characteristics of each urban street canyon. Urban–rural air temperature differences were considered to be not important if they were below the threshold value of 0.3°C. It was concluded that the major factor controlling urban–suburban air temperature differences was the geometry of the urban area. Other factors were the orientation of the observational sites, the current weather conditions, and the inversion of air masses adjacent to the ground level. An increase in the value of aspect ratios leads to a decrease in the difference between air inside the canyons and at the suburban station. The air temperature profile in an open-space area was the most important defining factor for the stratification of the urban–rural air temperature differences.
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Marcella ; Nancy Yusnita Nugroho, Gabriela. "INFLUENCE OF MASS ‘U’ FORM IN LINE UP FORMATION TOWARDS AIR MOVEMENT ON SUPPORTING THERMAL COMFORT IN OUTSIDE SPACE OF APARTMENT LANDMARK RESIDENCE, BANDUNG." Riset Arsitektur (RISA) 3, no. 04 (October 5, 2019): 398–413. http://dx.doi.org/10.26593/risa.v3i04.3522.398-413.
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Abstract- Indonesia with the characteristics of tropical climate requires control in design to achieve thermal comfort both in outside space and inside space. One of the factors that can affect thermal comfort is the pattern of air movement and air velocity. Landmark Residence Apartment is one of the new apartments in Bandung, with mass ‘U’ form in line up of new partially awakened. The newly constructed 'U' mass formation forms the characteristic of the two different masses, the space side in the closed A mass with the characteristic of the centered space as well as the side in the open mass B. this apartment become an object of research to determine the factors of order and mass form to the characteristics of air movement as well as thermal comfort in the outside space as a space of activities in residents. The method used in this research is descriptive-quantitative with simulation software Flow Design to know the air movement and measurement of thermal comfort factor at the point of population and sample which have been determined. This thermal factor will be analyzed using CET Nomogram method, so it generates thermal comfort level in outer space which will be associated with order and mass form of apartment. By using analysis of air movement patterns and CET Nomogram, it is seen that thermal comfort level in the outside space Landmark Residence apartment is more affected by wind velocity. The mass 'U' form with the back to wind direction will produce high wind velocity on the outside space of the building's side, while on the inner side of the 'U' form will form the shadow of the wind and the pattern of turbulence air movement affecting the achievement of different thermal conditions. The 'U' mass sequence lined up can also cause air movement on the inner side of closed A mass not getting enough air movement compared to open mass B with better airflow pattern. The pattern of air movement on the inner side of mass A can be at any time higher when the wind velocity enters the gap between the masses. Key Words: apartment, outside space, mass ‘U’ form in line up, air movement, thermal comfort.
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Won, Soo Ran, Young Sung Ghim, Jeonghoon Kim, Jungmin Ryu, In-Keun Shim, and Jongchun Lee. "Volatile Organic Compounds in Underground Shopping Districts in Korea." International Journal of Environmental Research and Public Health 18, no. 11 (May 21, 2021): 5508. http://dx.doi.org/10.3390/ijerph18115508.
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Underground shopping districts (USDs) are susceptible to severe indoor air pollution, which can adversely impact human health. We measured 24 volatile organic compounds (VOCs) in 13 USDs throughout South Korea from July to October 2017, and the human risk of inhaling hazardous substances was evaluated. The sum of the concentrations of the 24 VOCs was much higher inside the USDs than in the open air. Based on factor analysis, six indoor air pollution sources were identified. Despite the expectation of a partial outdoor effect, the impacts of the indoor emissions were significant, resulting in an indoor/outdoor (I/O) ratio of 5.9 and indicating elevated indoor air pollution. However, the effects of indoor emissions decreased, and the contributions of the pollution sources reduced when the USD entrances were open and the stores were closed. Although benzene, formaldehyde, and acetaldehyde exhibited lower concentrations compared to previous studies, they still posed health risks in both indoor and outdoor settings. Particularly, while the indoor excess cancer risk (ECR) of formaldehyde was ~10 times higher than its outdoor ECR, benzene had a low I/O ratio (1.1) and a similar ECR value. Therefore, indoor VOC concentrations could be reduced by managing inputs of open air into USDs.
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Jiang, Feng, Weilin Xu, Jun Deng, and Wangru Wei. "Flow Structures of the Air-Water Layer in the Free Surface Region of High-Speed Open Channel Flows." Mathematical Problems in Engineering 2020 (November 3, 2020): 1–10. http://dx.doi.org/10.1155/2020/5903763.
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In hydraulic engineering, intense free surface breakups have been observed to develop in high-speed open channel flows, resulting in a mixed air-water layer near the free surface that grows with the development of self-aeration. This region is characterized by a substantial number of droplets coexisting with an induced air layer above. Little information about this droplet layer is currently available and no practicable approach has been proposed for predicting the parameters of the induced air layer based on the related flow structures in the droplet layer. In this research, laboratory experiments were accordingly conducted to observe the detailed droplet layer development in terms of layer thickness, droplet size, and frequency distributions under comparative flow conditions. Based on the simplified droplet layer roughness determined using the experimentally measured mean droplet size, the classical power-law of boundary layer theory was applied to provide an analytical solution for the air velocity profile inside the air layer. The relationship of air layer growth to droplet layer thickness, which is a key factor when determining the air velocity distribution, was also established, and the analytical results were proven to be in reasonable agreement with air velocity profiles presented in the literature. By determining the relationship between droplet layer properties and air velocity profiles, the study establishes a basis for the improved modeling of high-speed open channel flows.
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Pietras, Katarzyna. "Comparison of Air Temperature Characteristics in Forest Communities in Puszcza Borecka and in Open Space." Miscellanea Geographica 14, no. 1 (December 1, 2010): 135–43. http://dx.doi.org/10.2478/mgrsd-2010-0013.
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Abstract Changes in similarities of five forest communities and of open space taking place during the year were analyzed in the scope of twelve daily and monthly characteristics of air temperature. The density of tree crowns having impact on the level of solar radiation reaching the ground during the day and the level of long term nocturnal emissions is the most important factor shaping thermal conditions in the forest.
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Sun, Han-Yin, Ci-Wen Luo, Yun-Wei Chiang, Kun-Lin Yeh Yi-Ching Li, Yung-Chung Ho, Shiuan-Shinn Lee, Wen-Ying Chen, Chun-Jung Chen, and Yu-Hsiang Kuan. "Association Between PM2.5 Exposure Level and Primary Open-Angle Glaucoma in Taiwanese Adults: A Nested Case–control Study." International Journal of Environmental Research and Public Health 18, no. 4 (February 10, 2021): 1714. http://dx.doi.org/10.3390/ijerph18041714.
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Primary open-angle glaucoma (POAG) is the most common type of glaucoma. However, little is known about POAG in adults and exposure to air pollution. The current study aims to investigate whether exposure to particulate matter with a mass median aerodynamic diameter of ≤2.5 μm (PM2.5) is associated with POAG diagnosis. Patient data were obtained from the Longitudinal Health Insurance Database 2010 (LHID2010) of Taiwan for the 2008–2013 period. PM2.5 concentration data, collected from the Ambient Air Quality Monitoring Network established by the Environmental Protection Administration of Taiwan, were categorized into four groups according to World Health Organization (WHO) exposure standards for PM2.5. We estimated the odds ratios (ORs) and 95% CIs for risk factors for POAG with logistic regression. The OR of per WHO standard level increase was 1.193 (95% CI 1.050–1.356). Compared with the normal level, the OR of WHO 2.0 level was 1.668 (95% CI 1.045–2.663, P < 0.05). After excluding confounding risk factors for POAG in this study, we determined that increased PM2.5 exposure is related to POAG risk (ORs > 1, P < 0.05). In this study, PM2.5 was an independent factor associated with open-angle glaucoma. Further research is required to better understand the mechanisms connecting PM2.5 and open-angle glaucoma.
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Kaulachs, I., A. Ivanova, A. Holsts, M. Roze, A. Flerov, A. Tokmakov, I. Mihailovs, and M. Rutkis. "Perovskite CH3NH3PbI3–XClx Solar Cells. Experimental Study of Initial Degradation Kinetics and Fill Factor Spectral Dependence." Latvian Journal of Physics and Technical Sciences 58, no. 1 (January 29, 2021): 53–69. http://dx.doi.org/10.2478/lpts-2021-0006.
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Abstract The main drawback of the methylammonium lead halide perovskite solar cells is their degradation in ambient atmosphere. To investigate ambient-air-induced cell degradation, spectral dependencies of open-circuit voltage (V OC ), fill factor (FF) and the power conversion efficiency (PCE) have been acquired (for the first time reported in literature). Our custom-made measurement system allowed us to perform measurements of the abovementioned entities in situ directly in vacuum during and after thermal deposition of the electrode. We also studied how these parameters in vacuum changed after cell exposure to ambient air for 85 min (50 nm top electrode) and for 180 min (100 nm top Ag electrode). For fresh CH3NH3PbI3–xClx cell (never been in open air) with very high shunt resistance of 3·107 Ω·cm2 (with practically no shorts and therefore FF could be determined mainly by charge carrier recombination processes) we found that FF in vacuum increased along with an increase of the incident photon energy from 0.55 at 760 nm up to 0.82 at 400 nm. Hypothesis considering hot polaron participation in charge carrier photogeneration and recombination processes as well as another competing hypothesis were offered as possible explanations for the observed FF increase. The kinetics of short-circuit photocurrent EQE with a change in pressure was also investigated. It was also shown that perovskite solar cell degradation could be noticeably reduced by increasing the top Ag electrode thickness to at least 100 nm, which could possibly facilitate the usual encapsulation process.
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Brkić, Dejan, and Pavel Praks. "Air-Forced Flow in Proton Exchange Membrane Fuel Cells: Calculation of Fan-Induced Friction in Open-Cathode Conduits with Virtual Roughness." Processes 8, no. 6 (June 11, 2020): 686. http://dx.doi.org/10.3390/pr8060686.
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Measurements of pressure drop during experiments with fan-induced air flow in the open-cathode proton exchange membrane fuel cells (PEMFCs) show that flow friction in its open-cathode side follows logarithmic law similar to Colebrook’s model for flow through pipes. The stable symbolic regression model for both laminar and turbulent flow presented in this article correlates air flow and pressure drop as a function of the variable flow friction factor which further depends on the Reynolds number and the virtual roughness. To follow the measured data, virtual inner roughness related to the mesh of conduits of fuel cell used in the mentioned experiment is 0.03086, whereas for pipes, real physical roughness of their inner pipe surface goes practically from 0 to 0.05. Numerical experiments indicate that the novel approximation of the Wright-ω function reduced the computational time from half of a minute to fragments of a second. The relative error of the estimated friction flow factor is less than 0.5%.
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Kondratyeva, I. Yu, and L. K. Gurkina. "Factors affecting the development of Phytophthora infestans on a tomato in the open ground." Vegetable crops of Russia, no. 6 (December 26, 2020): 112–15. http://dx.doi.org/10.18619/2072-9146-2020-6-112-115.
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Relevance and methods. For the Non-chernozem zone, the main factor for the active development of late blight is the low air temperature and its sharp fluctuations during the day, contributing to the formation of increased air humidity and drip-liquid moisture on the plants. In the Moscow region, the causative agent of late blight is manifested almost annually. Populations of Phytophthora infestans are represented by the To and T1 races. Epiphytotic development was observed periodically (1977-1979, 1982, 1986, 1996-1999, 2000, 2001, 2003-2004, 2008-2009, 2013, 2014, 2015, 2016, 2017, 2019) and was provided by the virulent T1 race. Observations showed that epiphytotic situations arose in those years when the minimum air temperature was below long-term average values, and relative humidity and precipitation exceeded them. With a deviation from the norm in the direction of increasing temperature, decreasing rainfall and relatively low humidity, years were observed with a depressive (1992, 1994) or moderate development of the disease (1980, 1981, 1983, 1985, 1987-1991, 2002, 2005-2007, 2010-2012, 2018). Results. As a result of breeding work, a Grot tomato-tolerant tomato variety was obtained, on the basis of which varieties with high resistance Grand, Dubok, Gnom, Chelnok, Patris, Geya, Zolushka, Perst, Severyanka, Blagodatny were obtained. In the general collection of VIR as a source resistance to leaf spot pathogens were registered: Geya (v.k. 14839), Slavyanka (v.k. 14840), Patrice (v.k. 14841), Rossiyanka (v.k. 14842), Krepysh (v.k. 14843), Sibiryachka (v.k. 14444) and line 1079-94 (v.k. 14845) donors, in addition to their high resistance to late blight, have excellent economic characteristics.
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Rathomi, Hilmi Sulaiman, and Eka Nurhayati. "Hambatan dalam Mewujudkan Open Defecation Free." Jurnal Integrasi Kesehatan & Sains 1, no. 1 (January 31, 2019): 68–73. http://dx.doi.org/10.29313/jiks.v1i1.4325.
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Open defecation free (ODF) merupakan salah satu target terpenting dalam Sustainable Development Goals (SDGs) yang ditujukan memutus rantai transmisi penyakit menular. Penelitian ini bertujuan mengetahui perilaku buang air besar sembarangan (BABS) yang masih dilakukan oleh masyarakat, sekaligus menganalisis berbagai faktor yang berpengaruh terhadap upaya eliminasinya menggunakan model behavior change wheel. Penelitian ini merupakan studi cross sectional dengan melibatkan 210 orang penduduk Desa Mangunjaya, Kabupaten Bandung yang dipilih secara cluster random sampling periode April 2017. Data diperoleh melalui wawancara menggunakan kuesioner tervalidasi, lalu dianalisis menggunakan software SPSS 20 dengan uji chi-square dan Spearman Rank Correlation. Hasil penelitian menunjukkan 28,6% penduduk Desa Mangunjaya yang masih mempraktikkan kebiasaan BAB sembarangan 22,4% penduduk yang tidak memiliki jamban. Ditemukan korelasi positif yang signifikan perilaku BABS dengan faktor motivasi (r=0,584), kemampuan (r=0,638), dan kesempatan (r=0,548). Terdapat perbedaan persepsi antara warga yang masih melakukan BABS dan yang tidak melakukan BABS mengenai faktor apa yang dinilai menghambat kepemilikan dan penggunaan jamban. Meskipun keduanya menyatakan bahwa faktor biaya adalah penghambatan utama, warga yang melakukan BABS cenderung menyalahkan lokasi desa sebagai hambatan terbesar kedua, sementara warga yang tidak BABS menilai bahwa kurangnya edukasi justru menjadi faktor terpenting selain hambatan biaya. Masih terdapat warga yang BABS dan tidak memiliki jamban dipengaruhi oleh faktor motivasi, kapabilitas, dan kesempatan. Peningkatan pengetahuan dan kepemilikan jamban perlu diupayakan lebih serius karena merupakan determinan terpenting pencapaian kondisi open defecation free di Desa Mangunjaya. BARRIER OF OPEN DEFECATION FREE Open defecation free (ODF) is one of the most important target in Sustainable Development Goals (SDGs) that is intended to break the transmission chain of infectious diseases. This research aims to discover the open defecation (OD) behavior as well as to analyze factors that influence its elimination effort using behavioral change wheel model. This was a cross sectional study involving 210 villagers from Desa Mangunjaya, Bandung during April 2017 who were randomly selected with cluster random sampling method. Data were taken through interview using validated questionnaire, then analyzed using SPSS 20 with chi-square and Spearman rank correlation test. This research found there were 28.6% of residents in Desa Mangunjaya who are still practising OD and 22.4% do not have latrines. There was a significant positive correlation between OD behavior with motivational factor (r = 0.584), capability (r: 0.638), and opportunity (r: 0.548). There was a difference of perception between residents who were still practicing OD and who were not, on what factors are considered to inhibit the ownership and use of latrines. Although both placed the cost factor as the main barrier, residents who practicing OD tend to assess the location of the village as the second greatest obstacle, meanwhile the second group put the lack of education as a major factor in addition to cost constraints. The achievement of ODF condition in Desa Mangunjaya was inhibited by motivational, capability, and opportunity factors. Increasing latrines ownership and knowledge among villagers were very crucial, since they are the most important determinants.
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Wei, Wei, Ming Cao, Qianling Jiang, Sheng-Jung Ou, and Hong Zou. "What Influences Chinese Consumers’ Adoption of Battery Electric Vehicles? A Preliminary Study Based on Factor Analysis." Energies 13, no. 5 (February 27, 2020): 1057. http://dx.doi.org/10.3390/en13051057.
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The rapid development of automobile industry in China did improve people’s quality of life. However, it has also damaged the ecological environment. The emission of a large amount of automobiles is one of the serious air pollution sources. In recent years, the shortage of petrochemical energy, the rapid rise of harmful particles in the air (e.g., PM2.5 and PM10), and the increasing worse atmospheric environment are becoming obstacles to China’s sustainable development. Battery electric vehicles (BEVs) are recognized as an ideal alternative to conventional cars. This study aims to explore the factors that can promote consumers’ adoption of BEVs and to construct domains of these factors. Firstly, an open web questionnaire and semi-structured interviews were conducted to widely collect factors that promote consumers’ purchase of BEVs. Then, questionnaire survey and exploratory factor analysis were used to construct domains of promoting consumers’ purchasing willingness. A total of six factors that promote consumers’ adoption of BEVs were obtained. Finally, the research results can provide references for the Chinese government and the BEV manufacturers in the development and promotion of EVs.
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Pouresmaeili, Esmaeil, Arash Ebrahimabadi, and Hadi Hamidian. "Sustainability assessment of an open-pit mine using a new model developed based on Folchi approach." Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, no. 6 (2021): 141–47. http://dx.doi.org/10.33271/nvngu/2021-6/141.
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Purpose. Surface mining is one of the main activities that affect the environment, economy and society in its surrounding region. Therefore, it is important to investigate the results of this activity in terms of sustainability assessment. Measuring sustainability of a mine requires a methodology which covers all aspects of mining sustainability.The purpose of the article is to assess the sustainability of career development and determine which components require modification and more consideration. Methodology.Many researchers have tried to develop certain frameworks to measure sustainable score of mining activities, while some of them are complicated and the rest of them do not cover all aspects of sustainability. In this research work, in order to evaluate the sustainability of an open-pit mine, Folchi method based on Multi-Criteria Decision Making (MCDM) approach was used. With this respect, primarily, influential factors and the impact of each influential factor on the sustainable component of an open-pit mine were investigated. Findings.In this regard, Anguran lead and zinc open-pit mine was chosen as a case study. A correlation matrix of the weighted impact of each influential factor on each environmental component was built up based on experts opinion. Afterwards, the magnitude of the influential factors and the impact of each influential factor on the sustainable component of Anguran mine were calculated. Originality. The results obtained using the Folchi method demonstrated that human health and safety, water quality, air quality, flora and fauna, as well as the surface have become decisive factors in the sustainability of Anguran open-pit mine. Practical value.Finally, it can be concluded that Anguran quarry is characterized by a significant degree of resilience due to the low level of influence of the influential factors, and there is no need to modify any influential factors.
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Vasina, Martin, Katarina Monkova, Peter Pavol Monka, Drazan Kozak, and Jozef Tkac. "Study of the Sound Absorption Properties of 3D-Printed Open-Porous ABS Material Structures." Polymers 12, no. 5 (May 6, 2020): 1062. http://dx.doi.org/10.3390/polym12051062.
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Noise pollution is a negative factor that affects our environment. It is, therefore, necessary to take appropriate measures to minimize it. This article deals with the sound absorption properties of open-porous Acrylonitrile Butadiene Styrene (ABS) material structures that were produced using 3D printing technology. The material’s ability to damp sound was evaluated based on the normal incidence sound absorption coefficient and the noise reduction coefficient, which were experimentally measured by the transfer function method using an acoustic impedance tube. The different factors that affect the sound absorption behavior of the studied ABS specimens are presented in this work. In this study, it was discovered that the sound absorption properties of the tested ABS samples are significantly influenced by many factors, namely by the type of 3D-printed, open-porous material structure, the excitation frequency, the sample thickness, and the air gap size behind the sound-absorbing materials inside the acoustic impedance tube.
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Lagnika, S. B. Mondoukpe, and Robert Hausler. "Environmental Risks in Open Pit Mines: Representation of a Temporal Evolution Related to Water Factor." Environmental Management and Sustainable Development 7, no. 4 (September 17, 2018): 22. http://dx.doi.org/10.5296/emsd.v7i4.13534.
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Natural resources are sources of much ecological instability. They are subjects of many types of research and led to the strengthening of measures. However, the exposure to hazards (water-air-soil pollution, radiation, degradation, etc.) due to such industries as mining continuous. This paper intends to show the dynamic relationships between production and time as part of the synergy of the whole extraction system over time. Given to sensitives issues known in the heart of mining operations, water is, therefore, the only environmental factor considered to lighten the research methodology. So, after the hypothesis, a temporal graphic with time and mining production level as explanatory and dependent variables is developed. Then, attention is given to the hypothesis validation used to highlight the joint result of the two variables. This is done by a literature review on environmental management risks tools existing, in-depth on the open pit mines with the simple linear regression analysis. The paired T-test Student result will help to clarify the potential of this statistical approach.
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Ageev, Igor M., and Yuri M. Rybin. "Measuring complex for monitoring carbon dioxide in air." Izmeritel`naya Tekhnika, no. 4 (2021): 68–71. http://dx.doi.org/10.32446/0368-1025it.2021-4-68-71.
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The advantages and disadvantages of infrared and electrochemical gas analyzers for carbon dioxide CO2 are described. The possibility of using conductometric sensors with distilled water for monitoring the CO2 content in the air has been investigated. Two identical measuring systems were manufactured, each containing two open-type conductometric cells, a matching device and a personal computer. With the help of these complexes, experiments were carried out on the simultaneous measurement of the CO2 content in the air in two places (a laboratory room and a building in a forest, located at a distance of 15 km from each other) with deliberately different daily dynamics of the CO2 level change. A special experiment was carried out, which made it possible to obtain an estimate of the inertia of conductometric cells and a conversion factor for the values of CO2 content into standard units of measurement. It is shown that the daily dynamics of changes in the electrical conductivity of distilled water in open cells corresponds to the expected dynamics of changes in the CO2 content in the rooms where the measurements were carried out. The operability of the measuring complex and the possibility of creating on its basis a device for long-term monitoring of the CO2 content in the air mixture of gases has been confirmed. The principal high selectivity of the measuring complex to CO2 in relation to other gases of the atmosphere has been established.
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Koya, Eitaro, Masahiko Nakagawa, Shinya Kitagawa, Jun Ishimoto, Yoshikatsu Nakano, and Naoya Ochiai. "CFD Analysis of Mechanisms Underlying the Porosity-reducing Effect of Atomized Flows in High-pressure Die Cast Products." MATEC Web of Conferences 326 (2020): 06006. http://dx.doi.org/10.1051/matecconf/202032606006.
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In high-pressure die casting, attention has been paid to the J factor, which is defined by the speed of the metal injected at the gate and the shape of the gate. In casting experiments using a piston die, the porosity of the product can be reduced by increasing the J factor such that the metal flow passing through the gate forms an atomized flow. To clarify the underlying mechanisms, we developed a system for simulating a two-phase flow of air and aluminum by large-scale calculations of turbulent flow. During the development of the system, we injected metal into an open space and performed imaging to confirm the state of the atomized flow. The system was then verified by reproducing the atomized flow. The analysis results visualized the many small turbulent vortices generated in the thick part far from the gate. We demonstrated that the change from small to longitudinal vortices promoted entrainment of air into the aluminum and increased the efficiency of air expulsion outside the die through an increase in the J factor.
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Ismainar, Hetty, Tety Kuniasari, and Ahmad Hanafi. "FAKTOR DOMINAN YANG MEMPENGARUHI PERILAKU BUANG AIR BESAR SEMBARANGAN (BABS) DI KOTA PEKANBARU, PROVINSI RIAU." JURNAL EKOLOGI KESEHATAN 20, no. 3 (March 10, 2022): 204–14. http://dx.doi.org/10.22435/jek.v20i3.5732.
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ABSTRACT
Open defecation is the act of disposing of waste in an area that can contaminate the environment. In Indonesia, there are still areas with Open Defecation Free (ODF) coverage that does not meet the national target (100%), one of which is in Pekanbaru City (28,6%). This study aims to explain the influence of environmental factors on defecation behavior. The type of research was quantitative with a cross-sectional design. A total of 194 families become respondents with proportional random sampling technique. Collecting data using a questionnaire. Data analysis was univariate, bivariate with chi-square test, and multivariate with logistic regression test. There were still 105 families (54.1%) who had open defecation. The variable that has a significant relationship with p-value <0.05 with open defecation behavior was latrine access (p=0.019), TOMA support (p=0.000), health care coaching (p=0.033), financial income (p=0.003) and habits (p=0.000). There were two dominant factors, namely habit with POR=3.771 (1.881-7.563) and TOMA support with POR=3.698 (1.872-7.034). Public awareness is needed, also increasing the frequency of home visits, socializing, and providing health information through print, electronic and social media.
Keywords: Open Defecation Free (ODF), Environmental Factor, Pekanbaru
ABSTRAK
Buang Air Besar Sembarangan (BABS) adalah tindakan membuang kotoran di area yang dapat mengkontaminasi lingkungan. Di Indonesia masih terdapat daerah dengan cakupan STOP BABS masih belum sesuai target nasional (100%), salah satunya di Kota Pekanbaru (28,6%). Penelitian ini bertujuan menjelaskan pengaruh faktor lingkungan terhadap perilaku BABS. Jenis penelitian kuantitatif dengan desain cross-sectional. Total 194 kepala keluarga (KK) yang menjadi responden dengan teknik proportional random sampling. Pengambilan data menggunakan kuesioner. Analisis data univariat, bivariat dengan uji chi-square dan multivariat dengan uji regresi logistic. Masih ditemukan 105 KK (54,1%) yang berperilaku BABS. Variabel yang memiliki hubungan yang signifikan p-value <0,05 dengan perilaku BABS yaitu akses jamban (p=0.019), dukungan TOMA (p=0.000), pembinaan nakes (p=0.033), pendapatan (p=0.003), dan kebiasaan (p=0.000). Terdapat dua faktor dominan yaitu kebiasaan dengan POR=3,771 (1,881-7,563) dan dukungan TOMA dengan POR=3,698 (1,872-7,034). Perlu kesadaran dari masyarakat, peningkatan frekuensi kunjungan rumah, sosialisasi dan pemberian informasi kesehatan melalui media cetak, elektronik juga media sosial.
Kata kunci: Perilaku Buang Air Besar Sembarangan (BABS), Faktor Lingkungan, Pekanbaru
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Granger, R. J., and N. Hedstrom. "Controls on open water evaporation." Hydrology and Earth System Sciences Discussions 7, no. 3 (May 4, 2010): 2709–26. http://dx.doi.org/10.5194/hessd-7-2709-2010.
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Abstract. The paper presents the initial results of a field study of boundary layer behaviour and open water evaporation carried out on two small- to medium-sized lakes in Western and Northern Canada. Meteorological and boundary layer measurements were made over the water surfaces and over the upwind land surface, allowing for an examination of the effect of lake-land contrasts of temperature on the wind speed over the open water and on the evaporation rates. Lake evaporation was measured directly using eddy covariance equipment. The study showed that, for time periods shorter than daily, the open water evaporation bears no relationship to the net radiation. The wind speed is the most significant factor governing the evaporation rates, followed by the land-water temperature contrast and the land-water vapour pressure contrast. The effect of the stability on the wind field is demonstrated; stability over the water and adjacent land surfaces are, for the most part, out of phase. The derived relationships will be used to develop a model for estimating the hourly evaporation rates from open water. Examination of the seasonal trends shows that the open water period can be separated into two distinct evaporative regimes: the warming period in the Spring, when the land temperature is greater than the water temperature, the turbulent fluxes over water are suppressed; and the cooling period, when the water temperature is greater than the air temperature, and the turbulent fluxes over water are enhanced.
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Sheikholeslami, Mohsen, and Davood Domiri Ganji. "Turbulent heat transfer enhancement in an air-to-water heat exchanger." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 231, no. 6 (August 31, 2016): 1235–48. http://dx.doi.org/10.1177/0954408916664758.
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Hydrothermal behavior in a water-to-air double-pipe heat exchanger is studied experimentally and numerically. To achieve fully developed conditions, the heat exchanger was built with additional lengths before and after the test section. Commercial code (ANSYS 14) is used for numerical section. In order to enhance rate of heat transfer, discontinuous helical fins is utilized. Results show that Nusselt number augments with the enhancement of Reynolds number and Prandtl number, which are calculated at bulk temperature. The use of square section helical fins also shows a higher heat transfer enhancement rate than that of the circular one. Thermal performance factor is an increasing function of the open area ratio.
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Dukhan, Nihad, Rubén Picón-Feliciano, and Ángel R. Álvarez-Hernández. "Air Flow Through Compressed and Uncompressed Aluminum Foam: Measurements and Correlations." Journal of Fluids Engineering 128, no. 5 (January 31, 2006): 1004–12. http://dx.doi.org/10.1115/1.2236132.
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Wind-tunnel steady-state unidirectional pressure-drop measurements for airflow through nine compressed and uncompressed isotropic open-cell aluminum foam samples, having different porosities and pore densities, were undertaken. The compressed foam produced significantly higher pressure drop, which increased with increasing Darcian velocity following the quadratic Forchheimer equation. The permeability and the inertia coefficient data for the compressed foam showed less scatter compared to those for the uncompressed foam. Both were correlated using an Ergun-like equation, with the correlation being better for the permeability. The permeability correlation predicted the results of some previous studies very well. The friction factor correlated well with the Reynolds number.
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Dirks, Kim, Nicholas Talbot, Jennifer Salmond, and Seosamh Costello. "In-Cabin Vehicle Carbon Monoxide Concentrations under Different Ventilation Settings." Atmosphere 9, no. 9 (August 28, 2018): 338. http://dx.doi.org/10.3390/atmos9090338.
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This paper explores the impact of choice of ventilation setting (“window open”, “new (external) air” and “recirculate”) on in-vehicle carbon monoxide exposures for commuters travelling by car at different times of the day (morning, midday, and evening) and different seasons (warm and cool) in Auckland, New Zealand. Three near-identical vehicles travelled in close proximity to each other on the same three “loops” out and into the city three times a day, each with a different ventilation setting. Concentrations of carbon monoxide were recorded using portable monitors placed inside each of the vehicles. The season was not found to be a significant factor. However, mean concentrations varied across ventilation settings by the time of day, typically peaking during the morning commute. The mean concentrations were significantly different between ventilation settings, with the recirculate setting found to result in a higher in-vehicle concentration than either new air or windows open but also heavily dependent on the initial in-vehicle concentration. However, this setting was the most effective at avoiding concentration spikes, especially when idling at intersections; an isolated peak event reaching 170 ppm was observed with the “new air” setting when following immediately behind an old, poorly-tuned, and visibly-emitting vehicle. This study suggests that having the windows open is the best setting for maintaining low in-cabin air pollution levels but that recirculate should be used in anticipation of congested conditions.
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M., Swapnajaswanth, Suryanarayana S. P., Suman G., and Murthy N. S. "A study to assess select risk factors for carcinoma cervix among patients attending Kidwai Memorial Institute of Oncology." International Journal Of Community Medicine And Public Health 4, no. 11 (October 25, 2017): 4238. http://dx.doi.org/10.18203/2394-6040.ijcmph20174836.
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Background: Cervical cancer is an important public health problem worldwide; it is second most common cancer among women aged 15-44 years globally (Globocan 2012). The objective of the study was to study the association between select risk factors and carcinoma cervix among patients attending Kidwai Memorial Institute of Oncology, Bangalore.Methods: Hospital based case- control study was carried among newly diagnosed cases of cervical cancer, cases and apparently healthy controls were selected. Statistical analysis was performed using, Chi square test of significance, logistic regression were preformed.Results: Univariate analysis revealed the following variables as significant risk factors these were Age at consummation of marriage <18 years OR 5.9 (2.6-19.4), Age 1st pregnancy <18 years OR 3.4 (2.2-5.2), live births delivered >5 OR 2.9 (1.7-5.8), marital status other than those who were married OR 1.7 (1.2-2.6), education of study subject being uneducated OR 3.9 (2.9-5.7), not washing genitals after sex OR 2.8 (1.6-4.9), material used during menstruation other than sanitary pads OR 6 (3.1-11.7), sex during menstruation OR 3 (1.1-7.9), not washing of private parts daily OR 10.8 (6.4-18.2), not taking bath daily OR 4.4 (2.8-7), open air defecation 7.6 (5.4-11.7), tobacco use OR 3.3 (2.2-5.6), never use of any contraceptive OR 3.7 (1.0-8.3) were significant at 0.05 level. Following backward multiple logistic regression analysis the following variables were independently associated with the development of cancer cervix, these were, age at 1st pregnancy <18 years OR 2.2 (1.2-3.8), use of material other than sanitary pads OR 3 (1.3-6.5), having sex during menstruation OR 4.3 (1.2-15), not washing of private parts daily OR 5.5 (2.9-10.4), open air defecation OR 2.6 (1.4-4.7), attained significance at 0.05 level.Conclusions: The study has revealed that age at 1st pregnancy <18 years, use of material other than sanitary pads, having sex during menstruation, not washing of private parts daily, open air defecation, as an independent risk factor for the development of cancer cervix. It can be noted that all the risk factor mentioned above is highly amenable for primary prevention.
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Gorbunov, Roman V., Vladimir A. Tabunshchik, Tatyana Yu Gorbunova, and Maria S. Safonova. "Dynamics of air temperature in the main types of mountain Crimea regional ecosystems." RUDN Journal of Ecology and Life Safety 29, no. 1 (December 15, 2021): 39–54. http://dx.doi.org/10.22363/2313-2310-2021-29-1-39-54.
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Climate change in Crimea is characterized by spatial heterogeneity in the displacement of air temperature fields, due to the influence of regional and local factors. There are currently no works devoted to the study of the reaction of regional ecosystems to changes in air temperature in Crimea. Based on open databases of reanalysis, geoinformation modeling the results of studies of the dynamics of air temperature in the main types of ecosystems of the Mountain Crimea under conditions of climate change are presented. For each circulation epoch and period of the Northern Hemisphere, maps of average annual temperatures were obtained along the landscape contours of the Crimean Peninsula. A map of the standard deviation of temperature within the landscape contours was made. For key areas, the mean annual air temperature, standard deviation, and factorial entropy were calculated. The main regularities of air temperature dynamics in the main types of Mountain Crimea ecosystems with the change of circulation epochs and periods of the Northern Hemisphere are revealed. Based on the analysis of the dynamics of the standard deviation and factor entropy, the role of changes in air temperature in the formation of strategies for the development or stabilization of the main types of regional ecosystems in Mountain Crimea is shown.
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Ghali, K., N. Ghaddar, and E. Jaroudi. "Heat and Moisture Transport Through the Microclimate Air Annulus of the Clothing-Skin System Under Periodic Motion." Journal of Heat Transfer 128, no. 9 (February 10, 2006): 908–18. http://dx.doi.org/10.1115/1.2241811.
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The study is concerned with the heat and moisture transport in a ventilated fabric-skin system composed of a microclimate air annulus that separates an outer cylindrical fabric boundary and an inner oscillating cylinder representing human skin boundary for open and closed aperture settings at the ends of the cylindrical system. The cylinder ventilation model of Ghaddar et al. (2005, Int. J. Heat Mass Transfer, 48(15), pp. 3151–3166) is modified to incorporate the heat and moisture transport from the skin when contact with fabric occurs at repetitive finite intervals during the motion cycle. During fabric skin contact, the heat and moisture transports are modeled based on the fabric dry and evaporative resistances at the localized touch regions at the top and bottom of points of the cylinder. Experiments were conducted to measure the mass transfer coefficient at the skin to the air annulus under periodic ventilation and to measure the sensible heat loss from the inner cylinder for the two cases of fabric-skin contact and no contact. The model predictions of time-averaged steady-periodic sensible heat loss agreed well with the experimentally measured values at different frequencies. The model results showed that the rate of heat loss increased with increased ventilation frequency at fixed (=amplitude/mean annular spacing). At amplitude factor of 1.4, the latent heat loss in the contact region increased by almost 40% compared to the loss at amplitude factor of 0.8 due to the increase in fabric temperature during contact. The sensible heat loss decreased slightly between 3% at f=60rpm and 5% at f=25rpm in the contact region due to higher air temperature and lack of heat loss by radiation when fabric and skin are in touch. The presence of an open aperture has a limited effect on increasing the total heat loss. For an open aperture system at amplitude factor of 1.4, the increase in heat loss over the closed apertures is 4.4%, 2.8%, and 2.2% at f=25, 40, and 60rpm, respectively.
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Flågan, Sigurd, Daniel Riedel, Alisa Javadi, Tomasz Jakubczyk, Patrick Maletinsky, and Richard J. Warburton. "A diamond-confined open microcavity featuring a high quality-factor and a small mode-volume." Journal of Applied Physics 131, no. 11 (March 21, 2022): 113102. http://dx.doi.org/10.1063/5.0081577.
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With a highly coherent, optically addressable electron spin, the nitrogen-vacancy (NV) center in diamond is a promising candidate for a node in a quantum network. A resonant microcavity can boost the flux of coherent photons emerging from single NV centers. Here, we present an open Fabry–Pérot microcavity geometry containing a single-crystal diamond membrane, which operates in a regime where the vacuum electric field is strongly confined to the diamond membrane. There is a field anti-node at the diamond–air interface. Despite the presence of surface losses, a finesse of [Formula: see text] was observed. The quality ([Formula: see text]) factor for the lowest mode number is [Formula: see text]; the mode volume [Formula: see text] is estimated to be [Formula: see text], where [Formula: see text] is the free-space wavelength. We investigate the interplay between different loss mechanisms and the impact these loss channels have on the performance of the cavity. This analysis suggests that the surface waviness (roughness with a spatial frequency comparable to that of the microcavity mode) is the mechanism preventing the [Formula: see text] ratio from reaching even higher values. Finally, we apply the extracted cavity parameters to the NV center and calculate a predicted Purcell factor exceeding 150.
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Liu, Tianzhu, Gao Lin, Hui Peng, Lesheng Huang, Xiaosong Jiang, Hongyi Li, Kaili Cai, et al. "Clinicopathological characteristics and prognosis of gastrointestinal stromal tumors containing air-fluid levels." PLOS ONE 16, no. 12 (December 17, 2021): e0261566. http://dx.doi.org/10.1371/journal.pone.0261566.
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An air-fluid level within a gastrointestinal stromal tumor (GIST) is unusual and indicates the presence of a fistula within the lumen of the GI tract. Until recently, the optimal management of such patients was not clear-cut. This retrospective study investigated the clinicopathological characteristics, surgical procedures, pre-and post-operative management, and prognosis of patients with GIST containing an air-fluid level. Data of GIST patients, spanning 5 years, including 17 GIST patients with air-fluid levels in the experimental group and 34 GIST patients without air-fluid levels in the control group, were retrieved from two hospitals in China. The clinicopathological characteristics, types of surgery, management, and clinical outcomes of GIST patients were compared between the two groups. GISTs containing air-fluid levels were significantly different from GISTs without air-fluid levels regarding tumor morphology, NIH risk category, invasion of adjacent organs, and necrosis or ulceration. Most GIST patients with air-fluid levels (14/17, 82.4%) received open surgery, significantly higher than the 20.6% in the control group. Targeted therapy with Imatinib mesylate (IM) was implemented in all GIST patients in the experimental group (17/17, 100%); markedly higher than those (3/34, 8.8%) in the control group. During follow-up, recurrence and death rates (5.9% and 5.9%) in the experimental group were higher than those (2.9% and 0%) in the control group. Open surgery is commonly performed in GIST patients with air-fluid levels who also require targeted therapy with IM. The Torricelli-Bernoulli sign could be a risk factor, adversely affecting the patient’s prognosis.
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Jiao, Ming Li, Shuang Hua Wang, and Wang Xi Zhang. "Electromagnetic Interference Shielding Properties of Silver-Plated Polyester Fabric." Applied Mechanics and Materials 239-240 (December 2012): 310–13. http://dx.doi.org/10.4028/www.scientific.net/amm.239-240.310.
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Over the last two decades, the electromagnetic radiation is becoming the fourth public pollution in addition to the noise, water and air pollution. Here, we had studied the structure and the electromagnetic properties of machine-knitted fabric coated with silver by means of microscopy and shielding effectiveness in the open space. The silver-plated polyester fabric showed a different shielding effectiveness of electromagnetic wave in the open space compared with enclosed space. The value of SE had closed relation with transmitting and receiving distance except the theory factor. When the frequency dropped below 900 MHz, the value SE usually became negative.
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Alam, Tabish, R. P. Saini, and J. S. Saini. "Heat Transfer Enhancement due to V-Shaped Perforated Blocks in a Solar Air Heater Duct." Applied Mechanics and Materials 619 (August 2014): 125–29. http://dx.doi.org/10.4028/www.scientific.net/amm.619.125.
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An experimental study of enhancement of heat transfer due to V-shaped perforated blockages attached to the heated surface has been presented in this paper. The duct equipped with perforated V-blocks had an aspect ratio (W/H) of 12, relative blockage height ratio (e/H) of 0.8, angle of attack (α) of 60° and open area ratio (β) of 20%, while relative pitch ratio (P/e) was varied from 4 to 12. The values of Nusselt number and friction factor of the duct with blockages were compared with values of Nusselt number and friction factor of the smooth duct operating under similar experimental conditions. It was found that there was a significant effect on the Nusselt number ratio and friction factor ratio when the pitch ratio was changed and there was exist an optimum value of pitch ratio. Thermal hydraulic performance was found to be maximum corresponding to relative pitch value of 8.
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Wang, Qi, Miao Tian, Yun Su, Xiang Hui Zhang, Yi Ting Xiao, and Jun Li. "Analyzing Garment Aperture Effect on Thermal Shrinkage of Flame Resistant Fabrics under Fire Exposure." AATCC Journal of Research 8, no. 2_suppl (December 2021): 63–67. http://dx.doi.org/10.14504/ajr.8.s2.13.
Full textAbstract:
Thermal shrinkage of flame resistant fabrics can greatly affect the thermal protection of firefighters’ clothing. In this study, four boundary conditions were designed to simulate garment aperture structures. Thermal shrinkage was measured with and without an air gap under three heat-flux levels. The shrinkage ratio was measured and calculated using digital image technology. Results showed that an air gap between the fabric and sensors was the main factor in thermal shrinkage. The presence of an air gap aggravates thermal shrinkage at the garment apertures, especially under the open boundary condition with incomplete fixation. The ease required for human movement and thermal shrinkage should be taken into consideration when designing thermal protective clothing. This study provides a quantitative method for determining the thermal shrinkage of fabrics.
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Thiagarajan, Krish P. "Hydrostatic Stability of Compartmented Structures Supported by Air Cushions." Journal of Ship Research 53, no. 03 (September 1, 2009): 151–58. http://dx.doi.org/10.5957/jsr.2009.53.3.151.
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This paper presents theoretical formulations to evaluate the restoring moment of structures supported by air cushions at zero forward speed. The air cushion is assumed to be enclosed within a number of compartments that are open to sea. The height of the water plug within the compartments is thus an important parameter. The theory, developed from first principles, is verified against data from inclining experiments conducted on a nine-compartment air cushion supported structure at different drafts and water plug heights. The theory shows that the air cushion affects the stability in two conflicting ways: favorable decrease in the vertical center of gravity caused by the water plug effect and unfavorable enhancement of the internal free surface effect. The net effect on stability depends on the operating conditions as well as on the scale of the structure being considered. A correction factor for the metacentric height incorporating the air cushion effects is proposed.
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Rasyida, Afinnisa. "Hubungan antara Persepsi terhadap Kualitas dan Pemanfaatan Ruang Terbuka Hijau dengan Kesejahteraan Psikologis Anak." TATALOKA 23, no. 3 (August 31, 2021): 404–17. http://dx.doi.org/10.14710/tataloka.23.3.404-417.
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Gresik Regency has been trying to implement a green open space policy in the form of a child-friendly park. It is very substantial for Gresik Regency to have a park that can be both as outdoor space for children and also air pollution filter. This study aims to identify the relationship between perceptions of the quality and utilization of green open space with child psychological well-being. Data was collected using Perception of the Quality and Utilization of Green Open Space scale and Strength and Difficulties Questionnaire that obtained from parent’s assessment. The results suggested that there was a relationship between the perception of the quality and utilization of green open space with the child’s psychological well-being in the dimension of strength, specifically in developing prosocial behavior. However, there was no relationship in the dimension of difficulties. The results also obtained that the perception of the quality and utilization of green space in Gresik was good. Even so, the community still perceived the lack of park safety factors. They also infrequently visit the park. These results can be used as an evaluation for the Local Regional Government to improve the safety and comfort factor of the park.
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Yuan, Lin, Mao, Li, Yang, Wei, and Xiao. "Performance Analysis of Heat Pump Dryer with Unit-Room in Cold Climate Regions." Energies 12, no. 16 (August 14, 2019): 3125. http://dx.doi.org/10.3390/en12163125.
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This study presents the development and evaluation of a novel partially open-loop heat pump dryer with a unit-room (HPDU). The unit-room was designed to enable the ambient air to be mixed with the return air, thereby reducing the influence of the ambient air on the system performance, while maintaining a high system thermal efficiency. A modelling system for the HPDU was developed and validated based on a real-scale experimental study. By using the modelling system, the system characteristics under different ambient conditions and bypass factors were analyzed. The energy benefit of the proposed HPDU was quantified through a comparative study with a closed-loop heat pump dryer (CHPD). It is evident that a maximal specific moisture extraction rate (SMER) and a minimal total energy consumption (TEC) existed when changing the bypass factor of the HPDU under certain ambient temperatures. Compared to the CHPD, the coefficient of performance (COP) of the HPDU increased by up to 39.56%, presenting a significant energy benefit for the application of HPDU.
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Lorn, Sokles, Pinnara Ket, Chanmoly Or, Sela Kong, Dalin Um, Srean Aun, Chanreaksmey Taing, and Leakhena Hang. "Health Impact Assessment from Rice Straw Production in Cambodia." Applied Sciences 12, no. 20 (October 12, 2022): 10276. http://dx.doi.org/10.3390/app122010276.
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Rice is a staple crop best known for its crucial role in feeding humans. In Cambodia, the human population depends on rice as its staple food. Increased rice production results in an increase in straw residue. The extensive residue caused by straw burning significantly contributes to high concentrations of air pollution, which are associated with critical health issues. As such, our objective in this study was to assess the human health impact of rice straw production in Cambodia. In this assessment, we focused on primary and secondary fine particulate matter formation (PM2.5, NH3, NOx, and SO2) from fertilizer, combustion of fuel in rice production processing, and burning of straw. We assessed endpoint impact by the following methods: (1) We estimated the proportion of rice straw from the annual rice production of the Ministry of Agriculture, Forestry, and Fisheries (MAFF) of Cambodia subjected to open burning in all 25 Cambodian provinces. (2) We calculated air pollutants emissions in terms of kilograms of pollutants per ton of rice produced by following the air pollutant emission inventory (EI) in the EMEP/EEA Guidebook for 2019, using data for fertilizer and fuel combustion that was applied in the field, based on a face-to-face survey of farmers. (3) We analyzed health impact in terms of DALYs using the characterization factor (CF) adapted from the ReCiPe 2016 v1.1 method. The results showed that the total health impact of rice straw production was 13,093.50 DALYs. Our analysis showed that open burning alone contributed 98.55% of the total health impact considered in this study, while fertilizers and combustion contributed only 0.12% and 1.33%, respectively. As the major of the total health impact arose from open burning, a policy of zero open burnings should be an effective way to reduce health impacts. These findings provide information for policymakers on how to alleviate air quality issues caused by the practice of open straw burning by adopting alternative techniques of rice straw management.