• Journal of Soil and Groundwater Environment
• /
• v.27 no.6
• /
• pp.11-21
• /
• 2022

Sorption of phenanthrene (PHE) and pyrene (PYR) in several sorbents, i.e., natural soil, BionSoil^®, Pahokee peat, vermicompost and Devonian Ohio Shale and a surfactant (hexadecyltrimethyl ammonium chloride)-modified montmorillonite (HDTMA-M) were investigated. Pyrene exhibited higher sorption tendency than phenanthrene, as predicted by its higher octanol to water partition coefficient (K_ow). Several sorption models: linear, Freundlich, solubility-normalized Freundlich model, and Polanyi-Manes model (PMM) were used to analyze sorption isotherms. Linear isotherms were observed for natural soil, BionSoil^®, Pahokee peat, vermicompost, while nonlinear Freundlich isotherms fitted for Ohio shale and HDTMA-M. The relationship between sorption model parameters, organic carbon content (f_oc), and elemental C/N ratio was studied. In the binary competitive sorption of phenanthrene and pyrene in natural soil, competition between the solutes caused reduction in the sorption of each solute compared with that in the single-solute system. The ideal adsorbed solution theory (IAST) coupled with the single-solute Freundlich model was not successful in describing the binary competitive sorption equilibria. This was due to the inherent nature of linear sorption of phenanthrene and pyrene in natural soil. The result indicates that the applicability of IAST for the prediction of binary competitive sorption is limited when the sorption isotherms are inherently linear.

• Journal of Soil and Groundwater Environment
• /
• v.28 no.5
• /
• pp.68-77
• /
• 2023

The effect of soil damage on the physicochemical characteristics and activity of the soil microbial community is not well known. This study investigates this relationship by analyzing 11 soil samples collected from various points of soil damage across Gyeonggi-do. Soil damage resulted from forest fires, landslides, and development areas, with their impacts most severe on the topsoil layer (0-30 cm). Dehydrogenase and β-glucosidase activities were notably higher at locations damaged by forest fires compared to other sites. While enzyme activities in soils influenced by landslides and development areas were relatively low, sites with a pollution history exhibited elevated dehydrogenase activity, likely due to past microbial response to the pollution. Additionally, an assessment of carbon substrate usability by soil microorganisms indicated higher substrate availability in areas impacted by forest fires, contrasting with lower availability in landslide and development sites. Statistical analysis revealed a positive correlation between organic content of sand and clay and microbial activity. These findings provide valuable insights into soil damage and associated restoration research, as well as management strategies.

• The Korean Journal of Pesticide Science
• /
• v.5 no.3
• /
• pp.26-35
• /
• 2001

In order to search potent antifungal substances from domestic plants, 40 plants cultivated in Korea were collected. After extracting with methanol (MeOH) and concentrating to dryness, the MeOH extracts were screened for in vivo antifungal activity against six plant diseases at a concentration of $2000{\mu}g/mL$. Fourteen extracts showed disease-controlling activity more than 90% against at least one of the 6 plant diseases tested; eight, seven, and three extracts controlled more than 90% the development of rice blast, tomato late blight, and wheat leaf rust, respectively. However, none of the extracts exhibited in vivo antifungal activity more than 90% against rice sheath blight, tomato gray mold, and barley powdery mildew. From the MeOH extracts of Angelica gigas and A. dahurica showing potent controlling activity against rice blast, 1 and 2 antifungal substances, respectively, were isolated by solvent partitioning and column chromatography. The three compounds were identified to be coumarins, namely, decursin, imperatorin, and isoimperatorin, by mass spectrometry and NMR spectroscopy. They were examined for in vitro and in vivo antifungal activities together with umbelliferone (7-bydroxycournarin) and scopoletin (6-methoxy-7-hydroxycoumarin) containing a free hydroxyl group at position 7 to investigate the structure-activity relationship. In vitro, most of 50% growth inhibitory concentrations ($IC_{50}$) were over $200{\mu}g/mL$, indicating that they have relatively weak antifungal activity. The antifungal activity of decursin and scopoletin, containing cyclic alkoxy groups instead of free hydroxyl group at position 7, was stronger than umbelliferone and scopoletin. Especially, decursin and imperatorin showed potent antifungal activities against Pythium ultimum and Magnaporthe grisea, respectively, with $IC_{50}$ values less than $25{\mu}g/mL$. In vivo, decursin and imperatorin showed potent antifungal activity against rice blast, whereas other coumarins hardly controlled the development of 6 plant diseases tested. These results suggest that the antifungal activity of 7-hydroxycoumarin derivative is substantially increased when the hydroxyl group at position 7 is protected by a stable cyclic alkoxy grouping.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.2 no.2
• /
• pp.19-29
• /
• 1994

A large volume of paper mill sludge(PMS) is produced every day from paper industries after treatments of waste water and it costs too much to dispose of the sludge. Since PMS consists mostly of biodegradable organic matter, cellulose, it is desirable to recycle it by proper treatments such as composting. In this study, experiments were conducted using a small scale reactor(12l) to establish optimum conditions for efficient composting of PMS of which initial pH, C/N ratio, and moisture content were 7.1, 28~30, and 60~65%, respectively. No heavy metals such as mercury, cadmimum, and lead were not detected in the PMS. Various levels of forced aeration, 1 minute aeration per every 30, 60, 120, 240, and 480 minutes were applied and 1 minute aeration per 60 and 120 minutes found to be proper for composting of 8l PMS in this system. Relationship between $CO_2$ production and temperatures was positively correlated with r> 0.82 suggesting that the normal decomposition of PMS by microorganisms occurred. However, under the condition of aeration interval over than 240 minutes, a negative relationship between two parameters was found indicating the occurrence of abnormal(maybe anaerobic) degradation. The amount of added nitrogen also affected composting of PMS resulting in the increase of $CO_2$ production and temperature. Semi-field tests using 100kg PMS in a static pile sysem showed that PMS could be composted efficiently under optimal environmental conditions. The parameters determining efficiency of composting such as C/N ratio, aeration, moisture content, and pH need to be monitored.

• Journal of Environmental Health Sciences
• /
• v.43 no.4
• /
• pp.324-333
• /
• 2017

Objectives: The purpose of this study was to assess the correlation relationship between personal exposure and urinary hippuric acid in biological monitoring for airborne toluene in an industrial complex and in general environments. Methods: Personal exposure to toluene and its metabolite, hippuric acid, in urine were simultaneously measured in occupational environments area near an industrial complex and in general environments. The study subjects were divided into three types: 137 workers who use organic solvents in the workplace, 210 residents living near a dyeing industrial complex, and 379 residents living in general environments. The toluene exposures of workers and residents were measured by a passive sampler for four days. The urine of participants was sampled when the passive samplers of personal exposure were collected. Results: The toluene and hippuric acid concentrations of workers were the highest, followed by the concentrations of residents living near a dyeing industrial complex and residents living in general environments. The coefficient of correlation between the concentrations of toluene and hippuric acid among workers was 0.749 (p<0.01) in the workplace. On the contrary, correlations between the concentrations of toluene and hippuric acid among residents living near a dyeing industrial complex and residents living in general environments were all not significant. The relationship between the concentrations of hippuric acid and toluene in three types could be described by the exponential growth model. Conclusions: This study analyzed the relationships between toluene exposure and the concentrations of hippuric acid in urine in high, middle, and low exposure environments, and could be described by the exponential growth model.

• Journal of Distribution Science
• /
• v.11 no.6
• /
• pp.81-89
• /
• 2013

Purpose - The market orientation of a manufacturer is a very critical competitive advantage factor in the development of new markets and the sustainability and maintenance of existing ones, achieved through the design of customer-oriented products. This is recognized as a virtuous circle, in which firms grow by means of promoting quality management. However, though market-oriented activities are important in management and operations, they seem to be promoted mainly by large-scale enterprises rather than by small- and medium-scale firms, the latter having invested relatively few company resources. Furthermore, few studies and analyses have examined how market orientation relates to the expansion of quality programs within organizations or with business performance; the market orientation and customer-orientation concepts are mixed together when both are used in research. Given the current market situation in which the servitization of manufacturing firms is rapidly expanding, this study's analysis of the effect on market orientation of manufacturers is a significant contribution. From this perspective, this study has several objectives. First, is to analyze and suggest the relationship between market orientation and quality management activity for manufacturers, focusing on three sub-activities: products, process, and quality management activities. Second, it is intended to identify correlation between manufacturers' market oriented activity and their management performance and then to analyze how market orientation affects business performance. The results of a number of prior studies on the correlation between market orientation and management performance have indicated that market orientation does affect management performance. Third, this study also investigates whether any differences in the relationship among market orientation, quality management activity and business performance occur according to company size. The results are used to present operational suggestions for large- and small- and medium-size firms. Research design, data, methodology - This study seeks to analyze and identify the causal features of the organic relationship among market orientation, quality management, and management performance for Korean manufacturing companies using three years (2005-2007) of market orientation, quality management, and business performance data. Subsequently, structural equation modeling was used to analyze the causal features of related factors and it aims to identify the features of market orientation, quality management, and business performance. Results - The analysis examined how market orientation affected the quality management and management performance of 159 smalland medium-size companies. In particular, enterprise quality management was analyzed in relation to management performance with a focus on activities such as leadership, measurement and improvement, quality control, cost management, and process management. Conclusions - The result of the analysis show that market orientation significantly affected all of the quality management activities and that market orientation in turn significantly affected organizational performance. The result of analysis indicate that quality management activities have a significant effect on quality control and cost management.

• Korean Journal of Psychosomatic Medicine
• /
• v.22 no.2
• /
• pp.55-62
• /
• 2014

The relationship of mind and body has stimulated extensive discussion for a long time. However, answers are ambigous and not forthcoming yet. Meanwhile, after the western medicine had embraced materialistic paradigm, conditions which cannot be substantiated by organic change were pushed out to periphery under the banner of "Medically Unexplained Symptoms". Medical experts endeavored to understand these mysterious illnesses based on the mind-body relationship and provided a frame of interpretation called Psychosomatic Medicine. This frame of interpretation had influenced not only the communication practice but also the health-seeking behavior and even the subjective experience of patients regarding their illnesses. The frame of interpretation had been drastically changed many times keeping pace with the socio-economic situation and the new scientific discoveries. Accordingly, body or mind was given differential importance by medical experts. For instance, when treatment modalities were lacking, mind was given excessive importance and patients were blamed for their unconscious motives, characterological weaknesses and for their lack of responsibility. In contrast, after the discovery of effective drug, mind was given no more attention and patients were no longer blamed for their contribution to suffering. In this paper, the historical change of the frame of interpretation for understanding migraine and headache was presented as an example. By this, it can be demonstrated how the frame of interpretation has modified the subjective experience of patients, and how the patients' responsibilities were viewed differently. This observation can help to realize the enormous influence of the frame of interpretation provided by medical experts.

• Culinary science and hospitality research
• /
• v.22 no.2
• /
• pp.136-150
• /
• 2016

As foodservice industry has been developing, more people are interested in healthy life and want to learn cooking. This study validated the moderating effect of education program on cooking institutes. Also the present study revealed cause and effect relationship among the education environment, the satisfaction and reregistration intentions by conducting a survey for trainees in cooking institutes located in Busan and Gyeongnam area. For the purposes of the study, conjunction and organic cause-and-effect relationship of entire model was validated by using an exploratory factor analysis, confirmatory factor analysis and structural equation modeling with 313 trainees who have used cooking institutes. A nested model and basic model were established to analyze the moderating effect of education program. The adjustment role of education program was validated with ${\chi}^2$ difference considering the degree of freedom between two models. As results of the analysis, the education service was statistically significant in all factors except the effect on education satisfaction. The education program has moderating effect on the relationship between the level of instructor and satisfaction degree, and between satisfaction degree and the reregistration intentions. Therefore, this study suggests that managers of cooking institutes should recruit instructors with excellent capability in order to operate the education program very well.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.6
• /
• pp.806-817
• /
• 2014

The objective of this experiment was to evaluate the effect of providing different levels of a supplement on the nutritional characteristics and productive performance of heifers on pasture during the rainy-dry transition and dry season in Brazil or tropical area. Thirty crossbred heifers with predominance of Zebu breed were used in a completely randomized experimental design. Treatments consisted of a mineral supplement and 0.5, 1.0, 1.5, or 2.0 kg/animal/d of a protein supplement containing 300 g crude protein (CP)/kg of dry matter (DM). In the rainy-dry transition season there was quadratic effect of the protein supplementation (p<0.10) on daily weight gain (DWG). A linear relationship (p<0.10) was found between increasing supplement intake and intakes of DM, organic matter (OM), crude protein (CP), ether extract (EE), non fibrous carbohydrates (NFC) and total digestible nutrients (TDN). Coefficients of apparent digestibility of CP, EE, and NFC increased linearly (p<0.10) with increasing supplement levels, but there was no effect on the DM apparent digestibility (p>0.10); the microbial efficiency (g CPmic/kg TDN) and the relationship of microbial nitrogen flow with nitrogen intake (g/g nitrogen intake) were negative linear profiles. In the dry season, the descriptive pattern least squares means showed a trend of stabilization of DWG from the supply of 0.98 kg of protein supplement; the intakes of DM, OM, CP, EE, NFC, and TDN showed increasing linear relationship (p<0.10) with protein supplement levels; the means of apparent digestibility coefficients of the different dietary fractions presented a linear-response-plateau (LRP); the microbial nitrogen flow (g/d) showed positive linear profile (p<0.10) for supplementation levels. It is concluded that supplementation improves the productive performance of grazing heifers and that 1.0 kg/d of supplement per animal gives the maximum increment of weight gain.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.5
• /
• pp.782-793
• /
• 1997

To study the physiological adaptation (shift-up) of phytoplankton under the simulated upwelling conditions, nitrate uptake capacity of Dunaliella tertiolecta batch culture was measured in the laboratory using the stable isotope $^{15}N-KNO_3$. Contrary to the expected, there was no significant relationship between the maximum $V_{NO3}$ (nitrogen specific nitrate uptake rate) and the initial nitrate concentration. However, there was a strong relationship between the maximum $\rho_{NO3}$ (nitrate transport rate) and the initial nitrate concentration of $<25\;{\mu}M$, which was also influenced by the physiological status of the culture. The increase in $V_{NO3}$ was mainly due to the increase in PON (particulate organic nitrogen) concentration and partly due to the increase in $V_{NO3}$. When the phytoplankton population was severely shifted-down, the physiological adaptation of nitrate uptake was significantly inhibited at high initial nitrate concentrations. The timing of the maximum $V_{NO3}$ or $\rho_{NO3}$ was related to the initial nitrate concentration. At higher initial nitrate concentrations, maxima in $V_{NO3}$ and $\rho_{NO3}$ occurred 1 or 2 days later than at lower nitrate concentrations. This relationship was the opposite to the prediction from the shift-up model of Zimmerman et al. (1987), The shift-up process is apparently controlled by an internal time sequence and the initial nitrate concentration, but the magnitude of $V_{NO3}$ was affected little by changes in nitrate concentration.