• Journal of Korean Society for Atmospheric Environment
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• v.28 no.3
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• pp.282-293
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• 2012

This study aimed to show the chemical characteristics of $PM_{10}$ and $PM_{2.5}$ during Asian dust (AD) events and high PM episodes observed in Seoul. Time-resolved chemical composition of $PM_{10}$ or $PM_{2.5}$ was monitored in 1 hour interval using ambient ion monitor, semi-continuous carbon monitor, and on-line XRF spectrometer at Seoul intensive monitoring site in 2009. Considering that AD events were classified into three different cases according to the source area and pathway, the concentrations of ammonium-sulfate and trace metal components were relatively high when the AD were occurred in Gobi and inner-mongolia and transported across the Bohai bay. In addition, the influence of alkaline dust, which carried from saline land located in the northeastern China, was observed when the AD was originated from Gobi, inner-mongolia, and Manchuria. Except AD events, the high PM episodes observed in Seoul were impacted by various anthropogenic sources such as biomass burning, motor vehicle, oil combustion and road dust.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.572-576
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• 2016

Soil quality assessment is an important tool for environmental management in an agricultural field. It can be used to evaluate the health of the soils and to establish the basis for sustainable urban agriculture and soil management. For this study, the chemical properties of the soils used for urban agriculture were examined. Results of the soil analysis for chemical properties were applied to soil quality assessment system, which is composed of principal component analysis, application to scoring function and derivation of soil quality index (SQI). Soil pH, electrical conductivity (EC), organic matter (OM), total nitrogen (T-N) were determined for minimum data set (MDS) according to principal component analysis. Based on the results of scoring for four indicators (pH, EC, OM, T-N), soil pH was the indicator that needs the most urgent management. Results of SQI derivation showed that many of the urban farms appeared to be insufficient score in comprehensive soil quality assessment. In conclusion, soil management practices based on scores derived from soil chemical indicators need to be carried out to maintain sustainable urban agricultural soil environment and to provide easy-to-understand information to urban farmers.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.110-119
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• 2024

Background: The Mae Kha Canal is one of Chiang Mai's most important waterways. It supports local agriculture, irrigation, and transportation as well as provides stormwater drainage to prevent floods. Due to the unregulated rapid urbanization of the city and lack of efficient waste and wastewater management systems over the past few decades, the canal has become heavily polluted. This study aimed to evaluate the water quality of Mae Kha canal through assessment of the physico-chemical water quality and coliform bacteria. Moreover, benthic macroinvertebrates were samples and assessed using the Biological Monitoring Working Party (BMWP^Thai) and Average Score Per Taxon (ASPT^Thai) as biological indices. Results: The physico-chemical showed low dissolved oxygen levels, high levels of ammonia and phosphates, and elevated levels of biochemical oxygen demand, indicating that the water quality had significantly deteriorated. The canal was found to be heavily polluted, with most sites falling into the polluted to very heavily polluted. Coliform bacteria analysis revealed alarmingly high levels of total coliform bacteria and fecal coliform bacteria in the canal. The BMWP^Thai and ASPT^Thai scores indicated poor to very poor water quality. Conclusions: The physico-chemical and coliform bacteria indicated that the water quality of the Mae Kha canal had significantly deteriorated. The biological indices also indicated the poor to very poor water quality. This study underscores the urgent need for comprehensive remediation efforts, emphasizing strategic planning, investment, and community engagement to revive the canal's ecological health and water quality.

• Safety and Health at Work
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• v.9 no.2
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• pp.159-163
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• 2018

Background: Fatigue and sleepiness are inter-related and common among road transport drivers. In this study, sleep deprivation and fatigue among chemical transportation drivers were examined. Methods: A cross-sectional study surveying 107 drivers from three hazardous types of chemical production and transportation industries (nonflammable gases, flammable gases, and flammable liquids) was conducted. Data on sleep deprivation were collected using questionnaires of the Stanford Sleeping Scale and the Groningen Sleep Quality Scale. Fatigue was assessed using an interview questionnaire and a flicker fusion instrument. Results: Chemical drivers had a mean sleeping scale (Stanford Sleeping Scale) of 1.98 (standard deviation 1.00) and had a mean score of 1.89 (standard deviation 2.06) on the Groningen Sleep Quality Scale. High-risk drivers had higher scores in both the Stanford Sleeping Scale and the Groningen Sleep Quality Scale with a mean score of 2.59 and 4.62, respectively, and those differences reached statistical significance (p < 0.05). The prevalence of fatigue, as assessed through a critical flicker fusion analyzer, subjective fatigue question, and either of the instruments, was 32.32%, 16.16%, and 43.43%, respectively. Drivers who slept <7 hours and had poor sleep quality were found to have more fatigue than those who slept enough and well. Drivers who had a more sleepiness score resulted in significantly more objective fatigue than those who had a less sleepiness score. Conclusion: Sleep quality and sleeping hour can affect a driver's fatigue. Optimization of work-rest model should be considered to improve productivity, driver retention, and road safety.

• Journal of the Korean Wood Science and Technology
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• v.48 no.4
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• pp.503-512
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• 2020

Using Na₂CO₃ versus NaCl as chemical activator, we compared the quality of activated carbon produced from oil palm fronds as raw material. These activators were selected for comparison because both are readily available and are environmentally friendly. In the manufacturing, we used Indonesian National Standard (SNI 06-3730-1995) parameters. For the quality comparison, we determined activated-carbon yield, moisture, ash, volatiles, and fixed-carbon contents; and adsorption capacity of iodine. The best characteristics, assessed by morphological surface analysis and Fourier transform infrared (FTIR) spectral analysis, were observed in the carbon activated by Na₂CO₃ at an activator concentration of 10% and carbonization temperature of 400 ℃. The results were as follows: activated-carbon yield, 84%; water content, 8.80%; ash content, 2.20%; volatiles content, 14.80%; fixed-carbon content, 68.60%; and adsorption capacity of iodine, 888.51 mg/g. Identification using the FTIR spectrophotometer showed the presence of the functional groups O-H, C=O, C=C, C-C, and C-H in the Na₂CO₃-activated carbon.

• Horticultural Science & Technology
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• v.34 no.6
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• pp.898-911
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• 2016

Sugars play many important roles in plant metabolism and directly influence fruit quality. The effects of two edible coatings, 2% calcium chloride and 1% pullulan, on sugar metabolism in postharvest Huangguan pear fruit were investigated during cold storage. The respiration rate, sugar content and composition, sucrose metabolism enzyme activities [acid invertase (AIV), neutral invertase (NI), sucrose synthase (SS), and sucrose phosphate synthase (SPS)] and expression of the AIV gene were analyzed during storage at $0^{\circ}C$ for 210 days. Coating treatments slowed the decrease of sucrose and hexose, the respiration rate, and the activities of AIV, NI, SS and SPS, thus maintaining high total soluble solids (TSS) and titratable acid (TA) contents in the fruit. There were no significant differences in AIV expression or activity between the treated and control groups of fruits. Both of the coatings could inhibit the activities of sucrose-cleaving enzymes, thus slowing the decrease of sugar content and maintaining high fruit quality during cold storage.

• Korean journal of food and cookery science
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• v.19 no.5
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• pp.631-639
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• 2003

In order to control the quality and safety of cooked foods, production and holding methods of foods should be carefully studied and applied to the foodservice industry. Therefore studies on microbiological, nutritional, physicochemical and sensory quality are essential in this area. The purpose of this study was to evaluate the chemical and microbial qualities of cooked foods during preparation and holding From the results, the following guidelines should be adhered to give effective quality control when holding foods after cooking in foodservice institutions, as well as to provide quality foods when selling cooked foods at commercial establishments. Sauteed and simmered foods such as sauteed chicken meat & vegetables and simmered pork in soy sauce satisfy the standard for microorganisms till 1-3 hours of room temp. holding, 6-18 hours at 60$^{\circ}C$ steam table, and 12-18 hours at 80$^{\circ}C$ heating table.

• 한국가스학회:학술대회논문집
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• 2003.10a
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• pp.126-130
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• 2003

• Journal of Korean Society on Water Environment
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• v.25 no.3
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• pp.394-403
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• 2009

A total of 52 sampling sites were selected in the stream network of the upper Paldang watershed (e.g. Kyonan, Gapyeong, Jojong, Chengmi, Bockha, Yanghwa and Heuk streams). Over the time period of April 2007-February 2008, 1820 samples were collected and analyzed for physico-chemical variables of the upper watershed in order to investigate spatio-temporal water quality variation in particular the relationship with land use. Although temporal variations of water quality in each stream were similar and were significantly influenced by flow, spatial variations in each stream varied as physico-chemical characteristics of upper watershed. As a result of regression analysis, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Nitrogen (T-N), and Total phosphorus (T-P) concentration were the most significantly and positively associated with people population density. It is necessary to manage not only water quality but also land use of upper watershed and flow flux.

• The Korean Journal of Ecology
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• v.21 no.6
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• pp.759-770
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• 1998

biotic indices scoring with the benthic macroinvertebrates were assessed as pollution monitoring tools in the north branch of the Han River system, Korea. We investigated the temporal variability of water quality at unpolluted, moderately polluted and heavily polluted sites using several biotic indices and assessed appropriate biological monitoring indices for lotic systems in Korea. The following biotic and chemical indices were employed in order to compare their applicability to the lotic systems : Trent Biotic Index (TBI), Chandler's Biotic Index-Average Score per Taxon (CBI-ASPT), Modified Biological Monitoring Working Party Score System-Average Score per Taxon (BMWP-ASPT), Hilsenhoff's biotic Index (BI) and Family-level Biotic Index (FBI) models for biotic analyses and National Sanitation foundation's Water Quality Index (NSFWQI) and comprehensive Chemical Pollution Index (Pb/n) for chemical analyses of water quality. Index and score values were compared with each other and with 24 water chemistry parameters. All biotic indices were significantly auto-correlated (p<0.001) and BI and FBI/ROK among them were highly correlated (r=0.84). BI and BMWP-ASPT models were also highly correlated with NSFWQI, while TBI values showed high correlation with the Pb/n. The BI and BMWP-ASPT were highly correlated with the most water chemistry parameters. We conclude that the BI model, which includes indicator species and abundance of taxa, is best suited for the bioassessment of lotic systems in Korea. For rapid field-based assessments, FBI/ROK and BMWP-ASPT models are also appropriate.