• Economic and Environmental Geology
• /
• v.56 no.6
• /
• pp.715-728
• /
• 2023

Tracksite of pterosaurs, birds, and dinosaurs in Chungmugong-dong in Jinju was designated as a natural monument in 2011 and is known as the world's largest in terms of the number and density of pterosaur footprints. This site has been managed by installing protection buildings to conserve in 2018. About 17% of the footprints of pterosaur, theropod, and ornithopod in this site under management in the 2nd protection building are of great academic value, but observation of footprints has difficulties due to continuous physical and chemical damage. In particular, the accumulation of milk-white contaminants is formed by the gypsum and air pollutant complex. Gypsum remains evaporated with a plate or columnar shape in the process of water circulation around the 2nd protection building, and the dust is from through the inflow of the gallery windows. The aqueous solution of gypsum, consisting of calcium from the lower bed and sulfur from grass growth, is catchmented into the groundwater from the area behind the protection building. Pollen and a few minerals other constituents of contaminants, go through the gallery window, which makes it difficult to expel dust. To conserve the fossil-bearing beds from two contaminants of different origins, controlling the water and atmospheric circulation of the 2nd protection building and removing the contaminants continuously is necessary. When cleaning contaminants, the steam cleaning method is sufficiently effective for powder-shaped milk-white contaminants. The fossil-bearing bed consists of dark gray shale with high laser absorption power; the laser cleaning method accompanies physical loss to fossils and sedimentary structures; therefore, avoiding it as much as possible is desirable.

• Membrane and Water Treatment
• /
• v.1 no.1
• /
• pp.83-92
• /
• 2010

To improve the antifouling characteristics of polypropylene hollow fiber microporous membranes in a submerged membrane-bioreactor for wastewater treatment, the surface-modification was conducted by Ar plasma treatment. Surface hydrophilicity was assessed by water contact angle measurements. The advancing and receding water contact angles reduced after the surface modification, and hysteresis between the advancing and receding water contact angles was enlarged after Ar plasma treatment due to the increased surface roughness after surface plasma treatment. After continuous operation in a submerged membrane-bioreactor for about 55 h, the flux recovery after water cleaning and the flux ratio after fouling were improved by 20.0 and 143.0%, while the reduction of flux was reduced by 28.6% for the surface modified membrane after 1 min Ar plasma treatment, compared to those of the unmodified membrane. Morphological observations showed that the mean membrane pore size after Ar plasma treatment reduced as a result of the deposition of the etched species; after it was used in the submerged membrane-bioreactor, the further decline of the mean membrane pore size was caused by the deposition of foulants. X-ray photoelectron spectroscopy and infrared spectroscopy confirmed that proteins and polysaccharide-like substances were the main foulants in the precipitate.

• Journal of the Korean Dietetic Association
• /
• v.14 no.2
• /
• pp.139-151
• /
• 2008

Presently, media for sanitation education consisting of a sanitation manual and a CD-ROM intended for restaurant employers and employees was developed and evaluated. The sanitation manual consisted of five principles: prevention of foodborne illness, personal hygiene, control of food production, instrument and equipment cleaning and sanitation, and management of environmental sanitation. The CD-ROM was composed of animations detailed real-life examples of Salmonella, Staphylococcus aureus, and Norovirus foodborned illness outbreaks; slides summarizing the five principles of the manual; and a poster entitled You can prevent foodborne illness listing and describing the principles. A 15 question evaluation survey was developed to gauge the efficacy of the animations. The survey was divided into five sections on comprehension of the instructions, content organization concerning understanding, content organization concerning the information presented, content organization concerning retention of interest (concentration), and recommendations concerning concentration. Ranked on a 5-point scale the survey produced a mean value of 3.80$\pm$0.39 and individual scores of 3.92$\pm$0.45 (learning instruction), 3.86$\pm$0.48 (understanding), 3.82$\pm$0.52 (information), 3.75$\pm$0.49 (concentration), and 3.67$\pm$0.58 (concentration-recommendation). Overall, evaluation results of the animation were good and easy to understand, with only a few respondents electing to watch the animations more than once. In terms of continuous and recurring education, sanitation training programs should be easy to learn and contain sufficient and specific examples of the importance of sanitation in achieving food safety.

• Journal of Korean Society of Water and Wastewater
• /
• v.28 no.2
• /
• pp.151-160
• /
• 2014

Capacitive deionization(CDI) has many advantages over other desalination technologies due to its low energy consumption, less environmental pollution and relative low fouling potential. The objectives of this study are evaluate the performance of CDI which can be used for dissolved salts removal from sewage. To identify ion selectivity of nitrate and phosphate in multiionic solutions and adsorption/desorption performance related to applied potential, a series of laboratory scale experiments were conducted using a CDI unit cell with activated carbon electrodes. The CDI process was able to achieve more than 75 % TDS and $NO_3{^-}$, $NH_4{^+}$ removals, while phosphate removal was 60.8 % and is inversely related in initial TDS and $HCO_3{^-}$ concentration. In continuous operation, increasing the inner cell pressure and reduction of TDS removal ability were investigated which are caused by inorganic scaling and biofouling. However a relative mild cleaning solution(5 % of citric acid for calcium scaling and 500 mg/L of NaOCl for organic fouling) restored the electrochemical adsorption capacity of the CDI unit to its initial level.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2002.05a
• /
• pp.12-16
• /
• 2002

Soil, ground water and sea bed are exposed to continuous accumulation of polluted materials causing serious environmental damage. It has been reported that such pollution causes a massive mortality of fish stock in rivers by the resuspension of toxic chemicals during strong wind conditions. Therefore, it becomes apparent that there is an immediate demand for the restoration treatment of polluted river bed (or sea bed) sediment layers. Pollution levels of major rivers and ports such as Pal-dang, Kyung-an rivers, Ma-san port are becoming public concern and are posing a serious environmental threat. In particular, the pollution of Shi-hwa river has become a nation wide issue for last few years. In spite of such public concern, the pollution level of such rivers or port are getting worse everyday. In this study, an environmentally sound engineering package is introduced which helps to restore the polluted river bed or sea bed sediments. This engineering package is consisted of a suction facility followed by a series of mechanical, chemical as well as biological treatment units. The suction facility is designed to minimize the secondary pollution due to the resuspension of toxic materials during suction. The sea bed cleaning engineering package is designed to be installed on the top of a floating barge. Such combination of environmental plant and shipbuilding technology provides a cost-effective solution, minimizing the cost involved in the transportation between suction and treatment facilities.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.18 no.1
• /
• pp.28-35
• /
• 2004

$N_2$ has been one of the most useful gases in industrial application, for example, plasma ashing, surface cleaning and decomposition of pollution gases. In order to clarify $N_2$ plasma properties and increase practical applications, many experimental and theoretical investigations have been carried out until now on. In this papa, we examined the characteristics of $N_2$ RF Plasmas using one-dimensional fluid model. $N_2$ plasmas showed a double-layer structure in both sheath regions as the power source voltage becomes higher. Generally, a double-layer structure should be showed in electro-negative plasmas, but not in electro-postive plasmas such as $N_2$ discharge. However, most electrons in $N_2$ plasmas lost their energy by many excitation reactions in the near of both electrodes where electron collisions were actively executed and such continuous reactions during an RF period made this structure strong with increase of the power source voltage. The dependence of $N_2$ plasma properties on pressure was also discussed.

• Journal of Home Health Care Nursing
• /
• v.9 no.1
• /
• pp.5-13
• /
• 2002

This study was conducted to assess need for education on the infection control by examining the knowledge on infection control in home care of the home care trainees who had completed an infection control course. Using 64 items questionnaire. home care trainees of eight home care education institutions who took classes related with infection control. The level of knowledge evaluated subjectively was 4.24point (full mark: 5 point). The correct answer rates for handwashing and gloving. cleaning patients' rooms. preventing sharp injury, preventing exposure to potential infectious agents, home care bag technique were 84.5% 86.4% 70.7% 65.3% 76.2% representatively. For the knowledge on the infection control principles to prevent catheter related infection, indwelling catheter related infection, tracheal tube related pneumonia. L-tube related infection, oxygen therapy related infection. and wound infection were 62.8% 27.8% 39.1% 87.8% 76.5% 80.5% representatively. The correct answer rates varied depending upon the educational institutes (p< = .0001), educational levels (p= .001), workplaces (p<.0001), and the experience of infection control education (p= .001). Considering these results. a standardized curriculum must be developed and implemented after analyzing the existing infection control curricula of the home care education institutes. and guide books for infection control in home care should be developed and distributed. In addition. continuous infection control education be provided to the home care nurses through reeducation so they can acquire new knowledge needed for carrying out infection control activities effectively.

• Journal of Conservation Science
• /
• v.32 no.3
• /
• pp.365-375
• /
• 2016

This study was interpreted the forming process of surface contaminants on ten-story stone pagoda of Wongaksa temple, Seoul. Results of research, we estimated that black contaminants were formed by graphite stuck carbon in air pollution substance after that gypsum was generated by chemical weathering on stone pagoda. White contaminants were built by recrystallization of calcite that were made by decomposition of finishing materials and structure on the stone surface. To preserve a long-term of stone pagoda in Wongaksa temple, there were required that continuous monitoring, anticorrosion treatment and contaminants cleaning of protective facilities.

• Journal of Korea Soil Environment Society
• /
• v.1 no.2
• /
• pp.61-72
• /
• 1996

A series of batch and lab-scale continuous tests were conducted to optimize the design parameters for the full-scale in-situ soil flushing experiments. The cleaning abilities of the surfactant solutions of Tween 80, Triton X-100 and SDS were compared for the soil artificially contaminated by hydrophobic organic contaminants: n-dodecane, naphthalene and anthracene. Tween 80 and Triton X-100 were shown to be efficient for n-dodecane. SDS and Tween 80 were shown to be efficient for naphthalene and anthracene. At the end of each column test, the sorbed amount of surfactant to soil was also measured. Tween 80 was found to be the least adsorbed surfactant to soil. The flushing ability at flowrate of 7 ml/min, was hampered comparing to flowrate of 3 and 5 ml/min. Initial pH of the soil did not significantly affect the flushing efficiencies. Tween 80 was determined as the most harmless surfactant for the Gram(+) and Gram(-) bacteria.

• Parasites, Hosts and Diseases
• /
• v.44 no.1 s.137
• /
• pp.73-79
• /
• 2006

We evaluated the efficacy of health education in reducing indoor arthropod allergens in Seoul. The mite control measures comprised the use of mite-proof mattress and pillow coverings, regular washing of potentially infested materials, maintenance of a low humidity, removal of carpets, and frequent vacuum cleaning. Cockroach control measures included trapping, application of insecticides, and protecting food. Of 201 homes enrolled in October 1999, 63 volunteers were included in a 2-year follow-up survey between April 2000 and January 2002. Before intervention, the density of mites/g of dust varied greatly; 27.1/g in children's bedding, 20/g in adult bedding, 7.2/g on the floors of children's bedrooms, 6.8/g in sofas, 5.9/g on the floors of adult's bedrooms, 3.9/g on living room floors, 3.7/g in carpets, and 1.9 mites/g on kitchen floors. The predominant mite species and house percentages infested were; Dermatophagoides farinae $93\%$, D. pteronyssinus $9\%$, and Tyrophagus putrescentiae $8\%$. Comparing 1999 and 2001 infestations, before and after 25 mo of education, mite abundance was reduced by $98\%$, from 23.7 to 0.57 mites/g of dust. In 1999, cockroaches were detected in $62\%$ homes: $36\%$ Blattella germanica and $35\%$ Periplaneta spp., including $9\%$ double infestations of B. germanica and P. americana. Following intervention, cockroach infestation rates decreased to $22\%$ of houses in 2000 and $23\%$ in 2001. We conclude that continuous and repetitive health education resulted in the effective control of domestic arthropods.