scholarly journals Developing Empirical Formula of Ventilation Index for Assessing PM2.5 Exposure in Biomass-Fuel Using Households

2021 ◽  
Vol 16 (1) ◽  
pp. 158-162
Author(s):  
Rengaraj Ramasamy ◽  
Krishnendu Mukhopadhyay
Keyword(s):  
Particulate Matter ◽  
Relative Humidity ◽  
Empirical Formula ◽  
Andhra Pradesh ◽  
Biomass Fuel ◽  
Indoor Environments ◽  
Inverse Relation ◽  
Air Velocity ◽  
Micron Size ◽  
Pm2.5 Exposure

Equations of ‘ventilation index’ in industrial and medical sectors are already established, but not yet been worked out for domestic household environments. This study intended to establish an empirical formula for ‘ventilation index’ for domestic indoor environments. Measurements of 2.5 micron size particulate matter (PM2.5) with biomass, air velocity, room index, temperature and relative humidity were used for developing the empirical formula. A total of 54 households from rural Andhra Pradesh and Karnataka states of India were selected. Average air velocity ranges in selected kitchens were categorised into three parts for developing ventilation indices in household kitchen environments. Observations in kitchen environments were found to be very interesting and promising. The formula captured inverse relation between PM2.5 and air velocities, consistently.

scholarly journals 512 PB 286 EFFECTS OF INTERIOR PLANTS ON RELATIVE HUMIDITY AND AIR-BORNE PARTICULATE MATTER IN INDOOR ENVIRONMENTS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 504g-504
Author(s):  
Virginia I. Lohr ◽  
Georgia K. Goodwin ◽  
Caroline H. Pearson-Mims
Keyword(s):  
Particulate Matter ◽  
Relative Humidity ◽  
Indoor Environments ◽  
Computer Lab ◽  
Foliage Plants ◽  
Growing Medium ◽  
Presence And Absence

Foliage plants were added to different environments, including an office and a computer lab. Relative humidity and air-borne particulate matter were monitored in the presence and absence of the plants. When the relative humidity was low, the addition of plants increased the relative humidity slightly, but significantly, over that when no plants were present. Particulate matter accumulation was not increased in the presence of plants. Some have hypothesized that the growing medium could be a source of increased particulates when plants are used indoors. Some of our experiments used self-watering containers, irrigated from below, resulting in very dusty conditions in the top of the container. If the growing medium could contribute to increases in particulate matter, we should have detected it in this study.

scholarly journals The Combined Effects of Fine Particulate Matter and Temperature on Preterm Birth in Seoul, 2010–2016

2021 ◽  
Vol 18 (4) ◽  
pp. 1463
Author(s):  
Youngrin Kwag ◽  
Min-ho Kim ◽  
Shinhee Ye ◽  
Jongmin Oh ◽  
Gyeyoon Yim ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Preterm Birth ◽  
Pregnant Women ◽  
Low Temperatures ◽  
Fine Particulate Matter ◽  
Temperature Data ◽  
Fine Particulate ◽  
The Mean ◽  
Pm2.5 Exposure ◽  
Pm2.5 Concentration

Background: Preterm birth contributes to the morbidity and mortality of newborns and infants. Recent studies have shown that maternal exposure to particulate matter and extreme temperatures results in immune dysfunction, which can induce preterm birth. This study aimed to evaluate the association between fine particulate matter (PM2.5) exposure, temperature, and preterm birth in Seoul, Republic of Korea. Methods: We used 2010–2016 birth data from Seoul, obtained from the Korea National Statistical Office Microdata. PM2.5 concentration data from Seoul were generated through the Community Multiscale Air Quality (CMAQ) model. Seoul temperature data were collected from the Korea Meteorological Administration (KMA). The exposure period of PM2.5 and temperature were divided into the first (TR1), second (TR2), and third (TR3) trimesters of pregnancy. The mean PM2.5 concentration was used in units of ×10 µg/m3 and the mean temperature was divided into four categories based on quartiles. Logistic regression analyses were performed to evaluate the association between PM2.5 exposure and preterm birth, as well as the combined effects of PM2.5 exposure and temperature on preterm birth. Result: In a model that includes three trimesters of PM2.5 and temperature data as exposures, which assumes an interaction between PM2.5 and temperature in each trimester, the risk of preterm birth was positively associated with TR1 PM2.5 exposure among pregnant women exposed to relatively low mean temperatures (<3.4 °C) during TR1 (OR 1.134, 95% CI 1.061–1.213, p < 0.001). Conclusions: When we assumed the interaction between PM2.5 exposure and temperature exposure, PM2.5 exposure during TR1 increased the risk of preterm birth among pregnant women exposed to low temperatures during TR1. Pregnant women should be aware of the risk associated with combined exposure to particulate matter and low temperatures during TR1 to prevent preterm birth.

scholarly journals Performance Evaluation of Particulate Matter and Indoor Microclimate Monitors in University Classrooms under COVID-19 Restrictions

2021 ◽  
Vol 18 (14) ◽  
pp. 7363
Author(s):  
Laurentiu Predescu ◽  
Daniel Dunea
Keyword(s):  
Performance Evaluation ◽  
Particulate Matter ◽  
Air Quality ◽  
Indoor Environment ◽  
Indoor Environments ◽  
University Campus ◽  
Particle Counter ◽  
Thermal Environments ◽  
University Classrooms ◽  
Academic Personnel

Optical monitors have proven their versatility into the studies of air quality in the workplace and indoor environments. The current study aimed to perform a screening of the indoor environment regarding the presence of various fractions of particulate matter (PM) and the specific thermal microclimate in a classroom occupied with students in March 2019 (before COVID-19 pandemic) and in March 2021 (during pandemic) at Valahia University Campus, Targoviste, Romania. The objectives were to assess the potential exposure of students and academic personnel to PM and to observe the performances of various sensors and monitors (particle counter, PM monitors, and indoor microclimate sensors). PM1 ranged between 29 and 41 μg m−3 and PM10 ranged between 30 and 42 μg m−3. It was observed that the particles belonged mostly to fine and submicrometric fractions in acceptable thermal environments according to the PPD and PMV indices. The particle counter recorded preponderantly 0.3, 0.5, and 1.0 micron categories. The average acute dose rate was estimated as 6.58 × 10−4 mg/kg-day (CV = 14.3%) for the 20–40 years range. Wearing masks may influence the indoor microclimate and PM levels but additional experiments should be performed at a finer scale.

CFD Simulation of Particle Transport and Dispersion in Indoor Environment by Human Walking

2012 ◽  
Author(s):  
Iman Goldasteh ◽  
Goodarz Ahmadi ◽  
Andrea Ferro
Keyword(s):  
Particulate Matter ◽  
High Speed ◽  
Cfd Simulation ◽  
Three Dimensional ◽  
Study Data ◽  
Turbulent Dispersion ◽  
Experimental Chamber ◽  
Indoor Environments ◽  
Three Dimensional Model ◽  
Particle Resuspension

Particle resuspension is an important source of particulate matter in indoor environments that significantly affects the indoor air quality and could potentially have adverse effect on human health. Earlier efforts to investigate indoor particle resuspension hypothesized that high speed airflow generated at the floor level during the gate cycle is the main cause of particle resuspension. The resuspended particles are then assumed to be dispersed by the airflow in the room, which is impacted by both the ventilation and the occupant movement, leading to increased PM concentration. In this study, a three dimensional model of a room was developed using FLUENT™ CFD package. A RANS approach with the RNG k-ε turbulence model was used for simulating the airflow field in the room for different ventilation conditions. The trajectories of resuspended particulate matter were computed with a Lagrangian method by solving the equations of particle motion. The effect of turbulent dispersion was included with the use of the eddy lifetime model. The resuspension of particles due to gait cycle was estimated and included in the computational model. The dispersion and transport of particles resuspended from flooring as well as particle re-deposition on flooring and walls were simulated. Particle concentrations in the room generated by the resuspension process were evaluated and the results were compared with experimental chamber study data as well as simplified model predictions, and good agreement was found.

Thermal Lethality of Salmonella in Chicken Leg Quarters Processed via an Air/Steam Impingement Oven

2004 ◽  
Vol 67 (3) ◽  
pp. 493-498 ◽  
Author(s):  
R. Y. MURPHY ◽  
K. H. DRISCOLL ◽  
L. K. DUNCAN ◽  
T. OSAILI ◽  
J. A. MARCY
Keyword(s):  
Relative Humidity ◽  
Surface Area ◽  
Air Temperature ◽  
Cooking Time ◽  
Air Velocity ◽  
Poultry Products ◽  
Product Surface ◽  
Cooking Times

Chicken leg quarters were injected with 0.1 ml of the cocktail culture per cm2 of the product surface area to contain about 7 log(CFU/g) of Salmonella. The inoculated leg quarters were processed in an air/steam impingement oven at an air temperature of 232°C, an air velocity of 1.4 m/s, and a relative humidity of 43%. The endpoint product temperatures were correlated with the cooking times. A model was developed for pathogen thermal lethality up to 7 log(CFU/g) reductions of Salmonella in correlation to the product mass (140 to 540 g) and cooking time (5 to 35 min). The results from this study are useful for validating thermal lethality of pathogens in poultry products that are cooked via impingement ovens.

scholarly journals Indoor Particulate Matter (PM2.5) and Comfort Parameters in a University Building

2020 ◽  
Vol 8 (2) ◽  
pp. 61-67
Author(s):  
Nurul Bahiyah Abd Wahid ◽  
Intan Idura Mohamad Isa ◽  
Ahmad Khairuddin Hassan ◽  
Muhammad Izzat Iman Razali ◽  
Ahmad Haziq Hasrizal ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Relative Humidity ◽  
Indoor Air ◽  
National Policy ◽  
Lecture Hall ◽  
Airborne Microorganisms ◽  
Code Of Practice ◽  
The Mean ◽  
Indoor Particulate Matter ◽  
Comfort Parameters

This study aims to determine the particulate matter (PM2.5) mass concentrations and the comfort parameters (total bacterial counts (TBC), total fungal counts (TFC), relative humidity and temperature) in a university building. The samplings were carried out in three different indoor areas, including lecture hall, laboratory and lecturer office. PM2.5 samples were collected over a period of 8 h sampling using a low volume sampler (LVS). The anemometer Model Kestrel 0855YEL was used to measure relative humidity and temperature parameters. The sampling of airborne microorganisms was conducted by using microbial sampler at 350 L air sampled volume. The results showed that the highest average of PM2.5 was at lecture hall (88.54 ± 26.21 µgm-3) followed by lecturer office (69.79 ± 19.06 µgm-3) and laboratory (47.92 ± 24.88 µgm-3). The mean of TBC and TFC readings recorded as follow; 32.71 ± 5.91 cfu m-3 and 76.71 ± 21.5 cfu m-3 for laboratory, 112.1 ± 29.06 cfu m-3 and 124.67 ± 23.35 cfu m-3 for lecturer office, 121.74 ± 19.33 cfu m-3 and 115.33 ± 8.08 cfu m-3 for lecture hall. The average of all comfort parameter was within the prescribed standard by Industry Code of Practice on Indoor Air Quality 2010 for all sampling sites. Therefore, all occupants of the building can work in a conducive and comfortable environment. This study is in line with the objectives of National Policy on the Environment (DASN), which focusing on achieving a clean, safe, healthy and productive environment for present and future generations.

scholarly journals Survey of residential indoor Particulate Matter measurements 1990-2019

2021 ◽  
Author(s):  
Vito A Ilacqua ◽  
Nicole Scharko ◽  
Jordan Zambrana ◽  
Daniel Malashock
Keyword(s):  
Particulate Matter ◽  
North America ◽  
Indoor Environments ◽  
Survey Period ◽  
Size Fractions ◽  
Comprehensive Collection ◽  
Air Cleaners ◽  
Solid Fuel Combustion ◽  
Indoor Particulate Matter ◽  
The Impact

We surveyed literature on measurements of indoor particulate matter in all size fractions, in residential environments free of solid fuel combustion. Data from worldwide studies from 1990-2019 were assembled into the most comprehensive collection to date. Out of 2,752 publications retrieved, 538 articles from 433 research projects met inclusion criteria and reported unique data, from which more than 2,000 unique sets of indoor PM measurements were collected. Distributions of mean concentrations were compiled, weighted by study size. Long-term trends, the impact of non-smoking, air cleaners, and the influence of outdoor PM were also evaluated. Similar patterns of indoor PM distributions for North America and Europe could reflect similarities in the indoor environments of these regions. Greater observed variability for all regions of Asia may reflect greater heterogeneity in indoor conditions, but also low numbers of studies for some regions. Indoor PM concentrations of all size fractions were mostly stable over the survey period, with the exception of observed declines in PM2.5 in European and North American studies, and in PM10 in North America. While outdoor concentrations were correlated with indoor concentrations across studies, indoor concentrations had higher variability, illustrating a limitation of using outdoor measurements to approximate indoor PM exposures.

scholarly journals A Study on Suitable Habitat for Swiftlet Farming

2009 ◽  
Vol 1 (1) ◽  
pp. 1-7
Author(s):  
Ibrahim S. H. ◽  
Teo W.C. ◽  
Baharun A.
Keyword(s):  
Relative Humidity ◽  
Light Intensity ◽  
Air Temperature ◽  
Capital Investment ◽  
Suitable Habitat ◽  
Key Factors ◽  
Air Velocity ◽  
Animal Products ◽  
New Industry ◽  
Temperature Surface

Swiftlet farming is a new industry in Sarawak as compared to other long-standing industries such as rubber, palm oil and timber. It is one of the businesses that involved a small capital investment that could generate enormous returns in the future. Swiftlet farming involves the conversion of human-centric building into structures for Swiftlet. The purpose of this conversion is to let Swiftlet for nesting and protect them. The design and construction of such building will also helps to accommodate Swiftlets' population. The nest of the Edible-nest Swiftlet rank amongst the world's most expensive animal products. Therefore, in order to increase the productivity of bird nest, study of the suitable habitat for Swiftlet should be done thoroughly. Environmental factors such as air temperature, surface temperature, relative humidity, air velocity and light intensity are the key factors for a successful Swiftlet farm house. Internal air temperature of building should be maintained from 26°C to 35°C, relative humidity from 80% to 90%, low air velocity and light intensity less than 5 LUX. Proper ventilation and installation of a humidifier could help the building to achieve the desirable range of environment factors. Location of structure will also be considered from direct sunlight direction to reduce the internal temperature. Only licensed Swiftlet farming is legal.

scholarly journals Experimental Measurements of Particulate Matter Deliquescence and Crystallization Relative Humidity: Application in Heritage Climatology

2015 ◽  
Vol 15 (2) ◽  
pp. 399-409 ◽  
Author(s):  
Marco Casati ◽  
Grazia Rovelli ◽  
Luca D’Angelo ◽  
Maria Grazia Perrone ◽  
Giorgia Sangiorgi ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Relative Humidity ◽  
Experimental Measurements

scholarly journals Karakteristik Pengeringan Biji Jagung (Zea Mays L.) Menggunakan Alat Pengering Surya Adriyarkara Termodifikasi

2018 ◽  
Vol 3 (2) ◽  
pp. 351-360
Author(s):  
Athul Fadhli ◽  
Diswandi Nurba ◽  
Raida Agustina
Keyword(s):  
Zea Mays ◽  
Relative Humidity ◽  
Moisture Content ◽  
Zea Mays L ◽  
Initial Moisture Content ◽  
Solar Irradiation ◽  
Air Velocity ◽  
Drying Time ◽  
Average Temperature ◽  
Average Relative Humidity

Abstrak. Jagung merupakan tanaman penghasil karbohidrat terpenting. Pengeringan jagung pipil menggunakan alat pengering merupakan proses untuk menghasilkan jagung pipil yang siap diolah untuk pembuatan tepung jagung dengan batas kadar air tertentu sehingga menghaslkan jagung pipil dengan kualitas yang baik. Tujuan penelitian ini adalah untuk mengkaji karakteristik pengeringan biji jagung menggunakan alat pengering surya Termodifikasi. Metode penelitian  menggunakan 3,15 kilogram jagung pipil dengan kadar air awal 22% untuk proses pengeringan. Parameter yang dianalisis terkait alat pengering kolektor surya yaitu temperatur, kelembaban relatif, kecepatan udara dan iradiasi surya, sedangkan parameter yang dianalisis terkait bahan yaitu kadar air, lama waktu pengeringan, laju pengeringan dan organoleptik. Prosedur penelitian terdiri dari pengujian kosong dan pengujian dengan menggunakan jagung pipil. Hasil penelitian menunjukkan bahwa temperatur rata-rata dalam rak pengering sebelum dilakukan modifikasi yaitu 44,4oC, temperatur rata-rata setelah dilakukan modifikasi yaitu 55,5oC dan temperatur rata-rata rak pengering pada pengeringan menggunakan jagung pipil yaitu 46,96oC. Kelembaban relatif rata-rata dalam rak pengering sebelum dilakukan modifikasi yaitu 40,1%, kelembaban relatif rata-rata dalam rak pengering setelah modifikasi yaitu 35,1% dan kelembaban relatif rata-rata pengeringan menggunakan jagung pipil yaitu 44,45%. Dari hasil pengukuran tersebut menunjukkan bahwa nilai temperatur dan kelembaban pada alat setelah modifikasi lebih baik dibandingkan sebelum alat dimodifikasi. Pengukuran temperatur dan kelembaban relatif terdiri dari 4 titik pengukuran yaitu rak 1A,1B dan rak 2A, 2B. Kecepatan udara rata-rata yang diukur konstan yaitu 0,7 m/s pada ruang pengering, sedangkan lingkungan 1,1 m/s. Total iradiasi surya selama pengeringan yaitu 1848,84 W/m2. Kadar air jagung pipil masing-masing rak yaitu rak 1A 14,29%, rak 1B 14,47%, rak 2A 13,91% dan rak 2B 14,1%. Hasil dari pengujian organoleptik, panelis agak menyukai jagung pipil yang dikeringkan menggunakan alat pengering tersebut.Characteristics of Seed Drying (Zea mays L.) Using a Modified Adriyarkara Solar DryerAbstract. Corn is the most important carbohydrate plant. Drying corn using a drying tool is a process to produce corn that are ready to be processed for making corn flour with a certain water content limit so as to produce corn with good quality. The purpose of this study was to examine the characteristics of drying of corn kernels using a modified solar dryer. The research method used 3,15 kilogram of corn milled with the initial moisture content of 22% for drying process. The parameters analyzed in relation to solar collector dryers are temperature, relative humidity, air velocity and solar irradiation, while the parameters analyzed are materials such as moisture content, drying time, drying rate and organoleptic. The research procedure consists of unloaded testing and testing using corn. The results showed that the average temperature in the dryer tray before modification was 44,4°C, the average temperature after modification was 55,5°C and the average temperature of the dryer tray on drying using corn was 46,96oC. The average relative humidity in the dryer tray before modification is 40,1%, the average relative humidity in the dryer tray after modification is 35,1% and the average relative humidity of drying using corn is 44,45%. From the measurement results show that the value of temperature and humidity in the tool after modification is better than before. Measurement of temperature and relative humidity consist of 4 point of measurement that is tray 1A, 1B and tray 2A, 2B. Average mean air velocity measured is 0,7 m/s at the dryer room, while the environment is 1,1 m/s. Total solar irradiation during drying is 1848,84 W/m2. Moisture level of corn each shelves tray 1A is 14,29%, tray 1B is 14.47%, tray 2A is 13,91% and tray 2B is 14,1%. As a result of organoleptic testing, panelists rather like dried corn using the dryer.

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