• Asian-Australasian Journal of Animal Sciences
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• v.30 no.4
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• pp.554-561
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• 2017

Objective: This experiment was conducted as a $3{\times}2{\times}2$ factorial design to examine the effects of particle size (mean particle size of 331, 640, or $862{\mu}m$), evaluation method (direct vs indirect method) and adaptation duration (7 or 26 days) on the energy content and the apparent total tract digestibility (ATTD) of various chemical components in wheat when fed to finishing pigs. Methods: Forty-two barrows ($Duroc{\times}Landrace{\times}Yorkshire$) with an initial body weight of $63.0{\pm}0.8kg$ were individually placed in metabolic cages and randomly allotted to 1 of 7 diets with 6 pigs fed each diet. For the indirect method, the pigs were fed either a corn-soybean meal based basal diet or diets in which 38.94% of the basal diet was substituted by wheat of the different particle sizes. In the direct method, the diets contained 97.34% wheat with the different particle sizes. For both the direct and indirect methods, the pigs were adapted to their diets for either 7 or 26 days. Results: A reduction in particle size linearly increased the digestible energy (DE) and metabolizable energy (ME) contents as well as the ATTD of gross energy, crude protein, organic matter, ether extract (EE) and acid detergent fiber (ADF) (p<0.05), and had a trend to increase the ATTD of dry matter of wheat (p = 0.084). The DE, ME contents, and ATTD of gross energy, crude protein, dry matter and organic matter were higher (p<0.05) when determined by the direct method, but the ATTD of ADF, EE, and neutral detergent fiber were higher when determined by the indirect method (p<0.05). Prolongation of the adaption duration decreased the ATTD of neutral detergent fiber (p<0.05) and had a trend to increase the ATTD of EE (p = 0.061). There were no interactions between particle size and the duration of the adaptation duration. The ATTD of EE in wheat was influenced by a trend of interaction between method and adaptation duration (p = 0.074). The ATTD of ADF and EE in wheat was influenced by an interaction between evaluation method and wheat particle size such that there were linear equations (p<0.01) about ATTD of ADF and EE when determined by the direct method but quadratic equations (p = 0.073 and p = 0.088, respectively) about ATTD of ADF and EE when determined by the indirect method. Conclusion: Decreasing particle size can improve the DE and ME contents of wheat; both of the direct and indirect methods of evaluation are suitable for evaluating the DE and ME contents of wheat with different particle sizes; and an adaptation duration of 7 d is sufficient to evaluate DE and ME contents of wheat in finishing pigs.

• Journal of the Korean earth science society
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• v.34 no.7
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• pp.693-710
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• 2013

This study investigates the distribution of suspended particulates during the Asian dust period in Busan, Korea in the spring of 2009. Weather map and automatic weather system (AWS) data were used to analyze the synoptic weather conditions during the period. Particulate matter 10, laser particle counter data, satellite images and a backward trajectories model were used to analyze the aerosol particles distribution and their origins. In Case 1 (20 February 2009), when the $PM_{10}$ concentration increased, the aerosol volume distribution of small ($0.3-1.0{\mu}m$) particles decreased, while the concentration of large ($1.0-10.0{\mu}m$) particles increased. When the $PM_{10}$ concentration decreased, the aerosol volume distribution was observed to decrease as well. The prevailing winds changed from weak northerly winds to strong southwesterly winds when the concentration of the large particles increased. The correlation coefficient between the $PM_{10}$ concentration and aerosol volume distribution of large particles showed a high positive value of over 0.9. The results from the trajectory model show that the Asian dust originated in the Gobi desert and the Nei Mongol plateau. In Case 2 (25 April 2009), when the $PM_{10}$ concentration increased, the aerosol volume concentration of small ($0.3-0.5{\mu}m$) particles decreased, but the concentration of large ($0.5-10.0{\mu}m$) particles increased. The opposite was observed when the $PM_{10}$ concentration decreased. The prevailing winds changed from northeasterly winds to southwesterly and northeasterly winds. The correlation coefficient between the $PM_{10}$ concentration and aerosol volume distribution of large particles ($1.0-10.0{\mu}m$) showed a high positive value of about 0.9. The results from the trajectory model show that the Asian dust originated in Manchuria and the eastern coast of China.

• Journal of Environmental Health Sciences
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• v.47 no.3
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• pp.267-278
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• 2021

Objectives: Using atmospheric dispersion representative models (AERMOD and CALPUFF), the emissions characteristics of each model were compared and analyzed in ready-mixed concrete manufacturing facilities that generate a large amount of particulate matter (PM-10, PM-2.5). Methods: The target facilities were the ready-mixed concrete manufacturing facilities (Siheung RMC, Goyang RMC, Ganggin RMC) and modeling for each facility was performed by dividing it into construction and operation times. The predicted points for each target facility were selected as 8-12ea (Siheung RMC 10, Goyang RMC 8, and Gangjin RMC 12ea) based on an area within a two-kilometer radius of each project district. The terrain input data was SRTM-3 (January-December 2019). The meteorological input data was divided into surface weather and upper layer weather data, and weather data near the same facility as the target facility was used. The predicted results were presented as a 24-hour average concentration and an annual average concentration. Results: First, overall, CALPUFF showed a tendency to predict higher concentrations than AERMOD. Second, there was almost no difference in the concentration between the two models in non-complex terrain such as in mountainous areas, but in complex terrain, CALPUFF predicted higher concentrations than AERMOD. This is believed to be because CALPUFF better reflected topographic characteristics. Third, both CALPUFF and AERMOD predicted lower concentrations during operation (85.2-99.7%) than during construction, and annual average concentrations (76.4-99.9%) lower than those at 24 hours. Fourth, in the ready-mixed concrete manufacturing facility, PM-10 concentration (about 40 ㎍/m³) was predicted to be higher than PM-2.5 (about 24 ㎍/m³). Conclusions: In complex terrain such as mountainous areas, CALPUFF predicted higher concentrations than AERMOD, which is thought to be because CALPUFF better reflected topographic characteristics. In the future, it is recommended that CALPUFF be used in complex terrain and AERMOD be used in other areas to save modeling time. In a ready-mixed concrete facility, PM-10, which has a relatively large particle size, is generated more than PM-2.5 due to the raw materials used and manufacturing characteristics.

• Particle and aerosol research
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• v.8 no.4
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• pp.151-160
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• 2012

Health effects caused by the ultrafine particles in ambient air are great concern to the public health, and the strict measuring and monitoring of the ambient aerosol are required. In this work, the characteristics of the aerosol size distribution in Pohang province are studied. Optical particle counters (Grimm APS 1108 and 1109) were used to measure the aerosol size distribution in the area. Locations near the national monitoring site located in the industrial and the residence area were selected for the measuring sites of this study, and the locations in border area between the industry and the residence were selected for the reference of the comparison. In the industry site, it is found that the concentration of aerosol particles near the size of 5 ${\mu}m$ appear characteristically and the fluctuations in concentration with respect to time are minimal. The mass concentration of the aerosol above 10 ${\mu}m$ in diameter in the industry area was found to fluctuate significantly. The mass portion of $PM_{10}$ and PM2.5 to TSP in the residence area were 83% and 51% respectively. In the industrial regional, it was found that the mass portion of PM10 and $PM_{2.5}$ to TSP were 76% and 35% respectively. In the boundary area the mass portion of $PM_{10}$ and $PM_{2.5}$ to TSP were 78% and 54% respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.345-352
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• 1999

The sand dollar, Astriclypeus manni is commonly encountered on a subtidal sand bottom along the coast of Cheju Island. limited information has been reported on their ecology despite their natural abundance. This study reports ecology and an annual reproductive cycle of the sand dollars present at Hamdock, northern coast of Cheju Island. A. manni collected from Hamdock revealed that they are 80 to 200 mm in test diameter. Sediment Brain size analysis indicated that A. manni mostly occurs on medium (particle diameter of 500 $\mu$m) to very find sand (particle diameter of 125 $\mu$m), particularly on fine sand (particle diameter of 250 $\mu$m). Internal morphology and in situ observations on their feeding habit indicated that A. manni is a deposit feeder, feeding on organic debris contained in the sediment around its habitat. A. manni were more frequently observed near Zostrea marina bed where content of organic matter in the sediment is considered to be higher. Gonadal tissues of the male were yellow in color while female gonads appeared to be purple. Fully mature eggs, with a mean diameter of 381 $\mu$m, and sperm were observed from the histological slides of the sand dollars collected in late July to August, suggesting that A. manni spawn during July to August when water temperature reaches 20 to $25^{\circ}C$.

• Journal of Animal Environmental Science
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• v.11 no.3
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• pp.197-206
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• 2005

This study was carried out to investigate the concentration and characteristics of dust originating from windowless broiler building in each season. 12.0m width and 46m tenth with side wall height of 3.0m was investigated and capacity was 12,800 birds at a stock density of 23.2 birds per square meter. Dust concentrations in terms of total suspended particles (TSP), and particulate matter of sizes $10{\mu}m(PM10),\;2.5{\mu}m (PM2.5),\;and\;1{\mu}m(PM1)$ were measured at 30-minute intervals. On the basis of broiler age, the average dust concentration in summer in TSP as follows: 1,229 904.5 558.8 and $1,053{\mu}g/m^3$ on the broilers' first to fourth week of age, respectively. But during winter, the average dust concentration showed an increasing pattern, as follows: 465.4, 1,401, 4,497, 5,097 and $6,873{\mu}g/m^3$ on the broilers' first to fifth week of age, respectively. The maximum dust concentration of $11,132{\mu}g/m^3$ was observed on the fifth week. On a daily basis, the maximum dust concentration during summer was detected in early morning, and the minimum in the afternoon. The aerial dust particle size of $0.05\~0.35{\mu}m$ was the highest in number. But on volume basis, particle size of 16~99 un had the largest percentage in the broiler house. Crude protein of the dust $(42.8\~65.2\%)$, on dry matter basis, was higher than that $(20.5\~24.5\%)$ fed to the broilers. Heavy metal concentration of the dust also had high levels compared with that of the feed.

• Journal of Wetlands Research
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• v.11 no.2
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• pp.47-54
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• 2009

This study was conducted to consider the characteristics of PM10(particulate matter with aerodynamic diameters less than 10 ${\mu}m$) concentration according to land-use in Busan coastal area. Fine particle is affected by emissions, geographical conditions and meteorological factors. In case industrial area, Gamjeondong(inland) PM10 concentration was higher than Noksandong(seashore) at all season except for Summer. Primary peak at Gamjeondong cleared than Noksandong in Fall and Winter. In case green area, Daejeodong(inland) PM10 concentration was higher than Dongsamdong(seashore) at all seasons. In case commercial area, primary peak occurrence time at Jeonpodong lagged one hour according to season and diurnal change of PM10 concentration at Gwangbokdong was higher than Jeonpodong in Spring. In case residential area, high PM10 concentration(80~90 ${\mu}g/m^3$) lasted for six hours during the daytime in Spring at Deogcheondong and Yongsuri(inland).

• Journal of Environmental Health Sciences
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• v.36 no.2
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• pp.108-117
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• 2010

In this study, ambient particulate matter ($PM_{2.5}$ and $PM_{10}$) levels were measured and their chemical and physical properties were characterized. Two sites in Gwangju were sampled once a month from December 2008 to November 2009. The annual mean concentrations of $PM_{2.5}$ and $PM_{10}$ were $26.9\;{\mu}g/m^3$ and $46.3\;{\mu}g/m^3$, respectively, in Nongseongdong and $26.1\;{\mu}g/m^3$ and $44.8\;{\mu}g/m^3$, respectively, in Duam-dong. $PM_{2.5}$ levels were 1.8 times higher than the USA Environmental Protection Agency (EPA) national ambient air quality standard for $PM_{2.5}$ ($15\;{\mu}g/m^3$). The average $PM_{2.5}/PM_{10}$ ratio of 0.58 suggested that $PM_{2.5}$ is a significant component of the ambient particle pollution. The order of concentration of metallic elements in $PM_{2.5}$ and $PM_{10}$ was Si > Al > Fe > Zn > Pb > Cu > Mn. Cd was not detected. The earth crustal enrichment factors for Cr, Cu, Pb and Zn in $PM_{2.5}$ were higher than those in $PM_{10}$. When the earth crustal enrichment factors for Cr, Cu, Pb and Zn were higher than 10, this suggested influence from anthropogenic sources. The soil contribution ratios for $PM_{2.5}$ and $PM_{10}$ were 11.3% and 16.4%, respectively, and were higher in the fall and winter. Anions (${SO_4}^{-2}$, ${NO_3}^-$, and $Cl^-$) comprise 28.7% of $PM_{2.5}$ and 21.4% of $PM_{10}$. The correlation coefficient of Zn-Fe, Mn-Cu, Fe-Cu and Fe-Mn in $PM_{2.5}$ was high in the sampling sites, and metallic elements were primarily from anthropogenic sources such as fuel combustion and vehicle emissions.

• Asian Journal of Atmospheric Environment
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• v.9 no.4
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• pp.280-287
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• 2015

The high time-resolution monitoring data are essential to estimate rapid changes in chemical compositions, concentrations, formation mechanisms, and likely sources of atmospheric particulate matter (PM). In this study, $PM_{2.5}$ sulfate, $PM_{2.5}$, $PM_{10}$, and the number concentration of size-resolved PMs were monitored in Fukuoka, Japan by good time-resolved methods during the springtime. The highest monthly average $PM_{2.5}$ sulfate was found in May ($8.85{\mu}g\;m^{-3}$), followed by April ($8.36{\mu}g\;m^{-3}$), March ($8.13{\mu}g\;m^{-3}$), and June ($7.22{\mu}g\;m^{-3}$). The cases exceed the Japanese central government's safety standard for $PM_{2.5}$ ($35{\mu}g\;m^{-3}$) reached 10.11% during four months campaign. The fraction of $PM_{2.5}$ sulfate to $PM_{2.5}$ varied from 12.05% to 68.11% with average value of 35.49% throughout the entire period of monitoring. This high proportion of sulfate in $PM_{2.5}$ is an obvious characteristic of the ambient $PM_{2.5}$ in Fukuoka during the springtime. However, the average fraction of $PM_{2.5}$ sulfate to $PM_{2.5}$ in three rain events occurred during our intensive campaign fell right down to 15.53%. Unusually high $PM_{2.5}$ sulfate (> $30{\mu}g\;m^{-3}$) marked on three days were probably affected by the air parcels coming from the Chinese continent, the natural sulfur in the remote marine atmosphere, and a large number of ships sailing on the nearby sea. The theoretical number concentration of $(NH_4)_2SO_4$ in $PM_{0.5-0.3}$ was originally calculated and then compared to $PM_{2.5}$ sulfate. A close resemblance between the diurnal variations of the theoretically calculated number concentration of $(NH_4)_2SO_4$ in $PM_{0.5-0.3}$ and $PM_{2.5}$ sulfate concentration indicates that the secondary formed $(NH_4)_2SO_4$ was the primary form of sulfate in $PM_{2.5}$ during our monitoring period.

• Journal of Korean Society on Water Environment
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• v.35 no.5
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• pp.409-417
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• 2019

In this study, a $480m^3/day$ pilot device was constructed through laboratory experiments based on the Ministry of Environment manual. The purpose of this study was to analyze the characteristics of CSO treatment and backwashing characteristics by applying the pilot device to the field. The purpose of this study was to acquire the basic data necessary for the design and operation management of the real scale filtration type non-point pollution control system. The filtration was conducted while maintaining the linear velocity of 20m/hour. The CSO treatment efficiencies of the pilot devices were 0.4-76.1%(mean 49.0 %), SS 51.4-91.6%(mean 77.8%), COD 22.2-59.4% (mean 38.3%) and TP 14.5-52.6%(mean 38.1%),respectively. The correlation coefficient between SS and the turbidity of influent water was 0.90, higher than that of CSO. To operate the treatment system effectively, the turbidity can be easily measured in real time as the monitoring item is the most appropriate because SS is the main target substance of the non-point source. As a result of analyzing the adsorbent treatment characteristics of PP filter material applied to this pilot device, the average particle diameter range of influent was $4.6-40.1{\mu}m$(mean $21.2{\mu}m$) and the treated water was $0.9-24.5{\mu}m$(mean $6.4{\mu}m$), respectively. Particles of approximately 10m or less are leached out, and so it is necessary to compensate for the raw water containing micro particulate matter.