• The Korean Journal of Ecology
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• v.20 no.1
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• pp.61-68
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• 1997

Due to its lack of wave action and tide ecosystem in Inchon dock lacks in marine characteristics. Structural condition in the dock is artificially similar to that of lake. The purposes of this study was to clarify the water quality, to provide the basic physicochemical data and tl resolve the causation of ？미 blooming. Samples were obtained monthly from four stations in Inchon dock during January to December, 1991. Water temperature ranged from $2.7^{\circ}C$ to $27.6^{\circ}C$ under the strong influence of air temperature. Salinity varied between 24.7%-30.4% thus being influenced by freshwater discharged from a spring. Dissolved oxygen was concentrated from 0.1-13.92 mg/l and suspended solids were 6.9-231.0 mg/l. The physicochemical factors were similar to those investigated 10 years ago. However, increased concentration of nitrogenous nutrients initiated ？미 blooming and its process was accelerated to reach eutrophication. Algal blooming was proceeded in March and August.

• Journal of Biosystems Engineering
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• v.23 no.5
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• pp.473-480
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• 1998

This study was performed to analyze the variation of various physicochemical factors related to the freshness of apple and tomato during post-harvest period. The total soluble solids content, uronic acid content, cell surface roughness. density, rupture deformation and rupture force were measured for 39 days at 7-day intervals for apple and for 11 days at 2-day intervals for tomato. respectively. The cell surface roughness of apple increased with the elapsed time, while the rupture force decreased. In case of tomato, uronic acid content, density and rupture deformation increased with the elapsed time whereas the rupture force decreased. Both apple and tomato exhibited the significant correlations among those physicochemical factors.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.322-329
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• 2018

In this study the community characteristics of benthic macroinvertebrates distributed in stream of Gaya Mountain were figured out and the correlation with the physicochemical water quality factors were calculated. During the study period, total 4 phyla, 6 classes, 13 orders, 36 families, 100 species of benthic macroinvertebrates were recorded. Ephemeroptera were the most dominant followed by Trichoptera, Plecoptera, Diptera, Non-insecta, Hemiptera, and Odonata. The overall dominant species was Cincticostella levanidovae by dominance rate in 17.72%, subdominant species was Hydatophylax nigrovittatus by dominance rate in 6.15%. The biotic indices showed the diversity index 5.17, richness index 12.44, dominant index 0.24 and evenness index 0.78, there is no absolutely dominant benthic macroinvertebrates in the stream of Gaya Mountain. We identified the correlation between the species number and individuals of main taxa and the physicochemical water quality factors. Ephemeroptera and Plecoptera showed a negative correlation with water temperature, but they represented a positive correlation with the dissolved oxygen. This results suggest that water temperature and dissolved oxygen are important physicochemical water quality factors affects the distribution of Ephemeroptera and Plecoptera, the indicators of clean water stream.

• Safety and Health at Work
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• v.10 no.4
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• pp.437-444
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• 2019

Background: Headache/eyestrain symptoms are common health problems that people experience in daily life. Various studies have examined risk factors contributing to headache/eyestrains, and physicochemical exposure was found to be a leading risk factor in causing such symptoms. The purpose of this study was to examine the relationship of headache/eyestrain symptoms with physicochemical exposure among Korean construction workers depended on worksite. Methods: This study used data from the 4th Korean Workers Conditions Survey and selected 1,945 Korean construction workers as participants. Multivariable logistic regression analysis was used to determine the relationship. Results: Exposure to vibrations among all construction workers affected the moderate exposure group [odds ratio (OR) 1.53, 95% confidence interval (CI) 1.01-2.32], the high exposure group (OR 1.77 95%CI 1.17-2.67), and the indoor high exposure group (OR 1.61, 95%CI 1.02-2.55) and among outdoor construction workers, the moderate group (OR 6.61, 95%CI 15.4-28.48) and the high group (OR 6.61, 95%CI 1.56-27.98). When exposed to mist, dust, and fumes, the indoor high exposure group was significantly affected (OR 1.63, 95%CI 1.07-2.47). All construction workers exposed to organic solvents were affected, high exposure group (OR 1.69, 95%CI 1.15-2.49) and indoor high exposure group (OR 1.77, 95%CI 1.08-2.89). The high exposure group in all construction worker (OR 1.70, 95%CI 1.20-2.42) and the indoor high exposure group (OR 1.83, 95%CI 1.17-2.89) also were affected by secondhand smoking exposure. Conclusion: Many physicochemical exposure factors affect headache/eyestrain symptoms among construction workers, especially indoor construction workers, suggesting a deficiency in occupational hygiene and health environments at indoor construction worksites.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1998.06b
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• pp.157-170
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• 1998

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.3
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• pp.251-268
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• 1986

Selecting a site for the safe disposal of radioactive waste requires the evaluation of a wide range of geologic, mineralogic, hydrologic, and physicochemical properties. Although highly diverse, these properties are in fact interrelated. Site requirements are also diverse because they are influenced by the nature of the radionuclides in the waste, for example, their half-lives, specific energy, and chemistry. A fundamental consideration in site selection is the mineralogy of the host rock, and one of the most ubiquitous mineral groups is clay minerals. Clays and clay minerals as in situ lithologic components and engineered barriers may playa significant role in retarding the migration of radionuclides. Their high sorptivity, longevity (stability), low permeability, and other physical factors should make them a very effective retainer of most radionuclides in nuclear wastes. There are, however, some unanswered questions. For example, how will their longevity and physicochemical properties be influenced by such factors as radionuclide concentration, radiation intensity, elevated temperatures, changes in redox condition, pH, and formation fluids for extended periods of time? Understanding of mechanisms affecting clay mineral-radionuclide interactions under prevailing geochemical conditions is important; however, the utilization of experimental geochemical information related to physicochemical properties of clays and clay-bearing materials with geohydrologic models presents a uniquely challenging problem in that many assessments have to be based on model predictions rather than on experiments. These are high-priority research investigations that need to be addressed before complete reliance for disposal area performance is made on clays and clay minerals.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.3
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• pp.484-490
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• 1996

Physicochemical changes were determined for the boiled-dried anchovies packaged in a laminated film(nylon 15${\mu}{\textrm}{m}$/polyethylene 100${\mu}{\textrm}{m}$) and stored for one year at ambient and cooling(5~1$0^{\circ}C$) temperatures after gamma irradiation. Lipophilic and hydrophilic browning pigments increased with storage time particularly at ambient temperature, even though initial 5 kGy irradiation did not affect the formation of pigments significantly. This results were confirmed by the instrumental color determinations, Hunter color L, a, b and ΔE. With respect to changes in relative fatty acid compositions, storage period and temperature were more influential factors than gamma irradiation. Irradiation at 5 kGy induced insignificant changes in the total flavor profiles of stored anchovies, which were mainly composed of n-dodecanal(26.7%), n-pentadecane(22.2%), n-octanal(4.9%) and 2-pentylfuran(3.4%).

• Environmental Analysis Health and Toxicology
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• v.14 no.1_2
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• pp.65-73
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• 1999

Dioxins refer to a family of chemicals comprising 75 polychlorinated dibenzo-p-dioxin (PCDD) and 135 polychlorinated dibenzo-p-furan (PCDF) congeners, which may cause skin disorder, human immune system disruption, birth defects, severe hormonal imbalance, and cancer. The effects of exposure of dioxin-like compounds such as PCBs are mediated by binding to the aryl hydrocarbon receptor (AHR), which is a ligand-activated transcription factor. To grasp physicochemical factors affecting human toxicity of dioxins, six geometrical and topological indices, eleven thermodynamic variables, and quantum mechanical descriptors including ESP (electrostatic potential) were analyzed using QSAR and semi-empirical AM1 method. Planar dioxins with high lipophilicity and large surface tension show the probability that negative electrostatic potential in the lateral oxygen may make hydrogen bonding with DNA bases to be a carcinogen.

• Journal of Environmental Health Sciences
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• v.27 no.4
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• pp.1-8
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• 2001

From August 2000 to August 2001, 9 variables of physicochemical factors and phytase activity were investigated at 4 sites in the River Yungpyung and the influences of Physicochemical factors to Phytase activity were analyzed. Phytase activities of Site 1, Site 2, Site 3, and Site 4 varied between N.D ∼566 nmol/ ι /hr, N.D \" 434 nmol/ ι /hr, N.D ∼557 nmol/ ι /hr, and N.D ∼723 nmol/ ι /hr, respectively. The activities of summer season were higher than those of other season. But the activities were not detected on the winter season. The phytase activity and temperature showed high correlation. The correlation coefficients of Site 1, Site 2, Site 3, and Site 4 were 0.82(p<0.01).0.92(p<0.01),0.87(p<0.01), and 0.88(p<0.01), respectively. The phytase activity and NOI₃/sup -/ ion showed negative relation(r=-0.59, p<0.05) at Site 1. And the phytase activity had relation with Zn/sup 2+/at Site 2(r=().57, p<0.05) and Site 3(r=0.7E, p<7.07).

• Journal of the Korean Society of Food Culture
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• v.37 no.4
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• pp.345-353
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• 2022

This study compared the physicochemical and gelatinization properties of naked barley, tetrastichum barley, and waxy barley. Compared to tetrastichum barley and waxy barley, naked barley had shorter and rounder grains with a 1.43 length/width ratio. Tetrastichum barley had lower crude protein, crude lipid, and crude ash content and higher amylose content compared to naked barley and waxy barley. The L, a, b color values of waxy barley were significantly higher than those of naked barley and tetrastichum barley. The water absorption index (WAI) and the water soluble index (WSI) were highest in waxy barley. The X-ray diffraction pattern was type A in all samples, and the peak intensity was highest in waxy barley. The maximum viscosity, cooling viscosity, breakdown, and setback of amylogram properties were the highest in tetrastichum barley. The thermal properties through the differential scanning calorimeter showed that the waxy barley had higher values of the onset, peak, conclusion temperature and enthalpy (?H). In conclusion, the variety of barley influenced the physicochemical and gelatinization properties, which could be important factors in the manufacture of processed foods. These results would thus useful inputs for the manufacturing of these foods using barley.