• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.12
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• pp.1781-1786
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• 2011

This study was conducted to investigate the cause of microbiological contamination in yogurt and evaluate the effect of physicochemical treatment on the growth inhibition of Hanseniaspora uvarum isolated from yogurt. The yeast strain Hanseniaspora uvarum Y1 was subjected to heat and pH treatments. H. uvarum Y1 was killed at $70^{\circ}C$ and $80^{\circ}C$ after 15 min and survived in a wide pH range from pH 2 to 9. However, it did not survive under pH 1 and over pH 10. In a disk diffusion susceptibility test on H. uvarum Y1, a clear zone (5 mm) of growth inhibition was observed upon treatment with electrolyzed water. The effect of ozone gas on the growth of H. uvarum Y1 was evaluated by viable cell count. Initial cell numbers of $10^2$ and $10^3$ CFU/mL of H. uvarum Y1 were completely killed by treatment for 10 and 30 min, respectively. H. uvarum Y1 was also sterilized by microwave treatment for 1 min. When treated with gamma-irradiation, the rate of killing of H. uvarum Y1 was proportional to the irradiation dose. and complete killing occurred at a dose of 50 kGy.

• The korean journal of orthodontics
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• v.29 no.5 s.76
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• pp.551-562
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• 1999

This study was undertaken to investigate the relation between orthodontic force magnitude and the amount of tooth movement. And more light force application for reducing root resorption Twenty-four rats were divided into three experimental groups(A, B, C) based on force magnitude and application method. Springs of 50g force were applied to A group, springs of 100g force were applied to B group and springs of 25g force were applied to C group initially, and after 4 days springs of C group were changed to springs of 50g force. Two kinds of $sentally^{(R)}$(GAC U.S.A.) closed coil spring, 50g and 100g, were used. And we made 25g springs by heat treatment process of 50g springs. Each spring was inserted between the maxillary central incisor and the maxillary left first molar. Amounts of tooth movement were measured everyday by digital caliper($Digimatic^{(R)}$, Mitutoyo, Japan) under inhalation anesthesia for 15 days. After 15 days, all rats were sacrificed and histological samples were obtained with Hematoxyline-Eosin stain and Masson's trichrome stain. Following conclusion were made; 1. Group B showed the mean cumulative tooth movement of $2.19{\pm}0.41mm$ at 15th day, which was greatest among three groups, followed by group C($2.06{\pm}0.10mm$), group A($1.90{\pm}0.49mm$) respectively. however, there was no statistically difference among three groups. 2. All groups showed general tooth movement pattern and A, B, C group finished lag phase at 9th, 8th, 7th day, but there was no statistical significance. 3. Group A,B,C showed root resorption and especially group B showed the most severe root resorption and group C showed milder root resorption than other groups. According to the above results, large initial force with the development of a flirty widespread hyalinized zone may cause severe root resorption, so initial force should be applied lightly to reduce hyalinized area and eventually root resorption and then increased force will induce efficient tooth movement.

• Journal of Korea Soil Environment Society
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• v.5 no.2
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• pp.55-66
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• 2000

A U.S EPA Synthetic soil matrix was used for reference neat soil and pyrene contaminated soil. For the contaminated soil, 4.79 wt.% pyrene was dissolved completely into the djchlorornethane, and the soil was evenly soaked with the pyrene solution. The contaminated soil samples(50$\pm$0.5mg) were heated in a modified electrical screen heater reactor which consisted of a thin stainless foil (3.5cm$\times$13cm$\times$0.00254cm, 302 stainless steel shim), two electrodes, and a 20cm dia. $\times$30cm tall cylindrical Pyrex chamber sealed at both ends by aluminum flanges. The heating rate and time conditions were selected as $455^{\circ}C$ @ $1137^{\circ}C$ /s, $760^{\circ}C$ @ $950^{\circ}C$ /s and $977^{\circ}C$ @ $977^{\circ}C$/s. Tar samples after heating the soils were collected on the aluminum foil funnel and a glass filter paper (25mm dia. filter paper) The tar sample and remnant soil on the reactor were extracted with dichloromethane covering the filters, foils and soil by sonicating each in the waterbath for 10 minutes. The extractions were run on a HPLC. At the low peak temperature(about $455^{\circ}C$ @ $1137^{\circ}C$/s) the color of tar was "white", at the middle peak temperature (about 76$0^{\circ}C$ @ 95$0^{\circ}C$/s) the color of tar was "pink brown", at the high peak temperature (about 977$^{\circ}C$ @ 977$^{\circ}C$/s) the color of tar was "dark brown". Cyclopeta(cd)pyrene (CPEP) , which is an interesting species due to mutagenic effect on human cells, was detected in tar samples only above the middle peak temperature. This species was not detected at the low peak temperature. Six isomers of bipyrene were detected. Phenanthrene(C$_{14}$ $H_{10}$) and cyclopenta(def)phenanthrene(C$_{15}$ $H_{10}$) were also detected, but their content was very small relative to the other listed compounds.to the other listed compounds.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.5-11
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• 2002

In this study, new development of natural ventilation window was accomplished to control environment of greenhouse with no use of farced ventilation during hot season. The ventilation effect of developed ventilation window was investigated in experimental greenhouse which was designed using side wall panel and folding type panel fur natural ventilation. Folding panel type ventilation window was designed to open upper part of the side wall and top of the roof using two hinges which are located bottom of the side wall and the roof panel to grab one side of each panels and guide the other side along with the guidance rail. Developed ventilation window has top ventilation part with maximum moving distance X=ι (1-cos$\theta$)=848.5 mm and side ventilation part with maximum moving distance Y=ι/2 $\times$sin$\theta$=1,184.4 mm at 45$^{\circ}$ of theoretical opening angle. It took 4.5 minutes to open roof vent fully and temperature at 1.2 and 0.8 m height decreased after 1 minute from starting opening and became equilibrium state maintaining 3-4$^{\circ}C$ difference after 2 minutes from complete opening. Air exchange rate was 15.2~39.3 h$^{-1}$ which was more than 10~15 h$^{-1}$ of continuous type and Venlo type greenhouse. The descent effect of temperature by ventilation windows was two times higher than Venlo type greenhouse.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.5
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• pp.341-358
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• 1992

In order to estimate energy budgets of Palaemon macrodactylus, larvae of the shrimp were reared in the laboratory at constant conditions $(25^{\circ}C: 31-32\%o),$ and then juvenile to adult of the shrimp were reared at $15^{\circ}C\;and\;25^{\circ}C$ in the laboratory. Energy used by the reared shrimps were calculated from estimates of data on feeding, growth, molting, metabolism, nitrogen excretion, and energy content. Juveniles and adults reared in the laboratory, which fed on Artemia nauplii, had an average daily growth rates of 0.079 mm/day at $15^{\circ}C\;and\;of\;0.122mm/day\;at\;25^{\circ}C$. The average growth factor* of P. macrodactylus males and females ranged from $3.2\%$ for adult to $13.2\%$ for juveniles individuals, respectively. Intermolt periods were related to body size of the shrimp and to temperature. Average laboratory growth curves were calculated from data on growth factors and intermolt periods to body size of the shrimp at $15^{\circ}C\;and\;25^{\circ}C$. The calorie contents of the shrimp, their molts, eggs and larvae were determined by biochemical composition and oxygen bomb calorimetry. The average amount of energy used in growth for larvae and juvenile to adult were 4.94 cal and 4.55 cal per dry weight in milligram, respectively. The ammount of oxygen used in metabolism was calculated from size, temperature-specific respiration rate. To convert the ammount of oxygen used in respiration into the equivalent energy lost heat was estimated from the data on chemical composition for the larvae and adult, the values was 4.58 cal/ml $O_2$. The energy content per egg was 0.078 cal. The assimilation efficiency estimated by nitrogen content of food and egested faeces gave $61.5\%$ for the larvae. The efficiencies for juvenile to adult ranged between $79.4\%$ and $90.1\%$ The gross growth efficiencies $(K_1)$ and net growth efficiencies $(K_2)$ of P macrodactylus showed $18.33\%\;and 32.63\%$ for total larval stages, ranged from $21.30\%\;to\;31.04\%\;and\;from\;30.03\%\;to\;39.34\%$ for juvenile to adult, respectively.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.05
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• pp.27-47
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• 1992

Engineers have developed new instruments that aid in diagnosis and therapy Ultrasonic imaging has provided a nondamaging method of imaging internal organs. A complex transducer emits ultrasonic waves at many angles and reconstructs a map of internal anatomy and also velocities of blood in vessels. Fast computed tomography permits reconstruction of the 3-dimensional anatomy and perfusion of the heart at 20-Hz rates. Positron emission tomography uses certain isotopes that produce positrons that react with electrons to simultaneously emit two gamma rays in opposite directions. It locates the region of origin by using a ring of discrete scintillation detectors, each in electronic coincidence with an opposing detector. In magnetic resonance imaging, the patient is placed in a very strong magnetic field. The precessing of the hydrogen atoms is perturbed by an interrogating field to yield two-dimensional images of soft tissue having exceptional clarity. As an alternative to radiology image processing, film archiving, and retrieval, picture archiving and communication systems (PACS) are being implemented. Images from computed radiography, magnetic resonance imaging (MRI), nuclear medicine, and ultrasound are digitized, transmitted, and stored in computers for retrieval at distributed work stations. In electrical impedance tomography, electrodes are placed around the thorax. 50-kHz current is injected between two electrodes and voltages are measured on all other electrodes. A computer processes the data to yield an image of the resistivity of a 2-dimensional slice of the thorax. During fetal monitoring, a corkscrew electrode is screwed into the fetal scalp to measure the fetal electrocardiogram. Correlations with uterine contractions yield information on the status of the fetus during delivery To measure cardiac output by thermodilution, cold saline is injected into the right atrium. A thermistor in the right pulmonary artery yields temperature measurements, from which we can calculate cardiac output. In impedance cardiography, we measure the changes in electrical impedance as the heart ejects blood into the arteries. Motion artifacts are large, so signal averaging is useful during monitoring. An intraarterial blood gas monitoring system permits monitoring in real time. Light is sent down optical fibers inserted into the radial artery, where it is absorbed by dyes, which reemit the light at a different wavelength. The emitted light travels up optical fibers where an external instrument determines O2, CO2, and pH. Therapeutic devices include the electrosurgical unit. A high-frequency electric arc is drawn between the knife and the tissue. The arc cuts and the heat coagulates, thus preventing blood loss. Hyperthermia has demonstrated antitumor effects in patients in whom all conventional modes of therapy have failed. Methods of raising tumor temperature include focused ultrasound, radio-frequency power through needles, or microwaves. When the heart stops pumping, we use the defibrillator to restore normal pumping. A brief, high-current pulse through the heart synchronizes all cardiac fibers to restore normal rhythm. When the cardiac rhythm is too slow, we implant the cardiac pacemaker. An electrode within the heart stimulates the cardiac muscle to contract at the normal rate. When the cardiac valves are narrowed or leak, we implant an artificial valve. Silicone rubber and Teflon are used for biocompatibility. Artificial hearts powered by pneumatic hoses have been implanted in humans. However, the quality of life gradually degrades, and death ensues. When kidney stones develop, lithotripsy is used. A spark creates a pressure wave, which is focused on the stone and fragments it. The pieces pass out normally. When kidneys fail, the blood is cleansed during hemodialysis. Urea passes through a porous membrane to a dialysate bath to lower its concentration in the blood. The blind are able to read by scanning the Optacon with their fingertips. A camera scans letters and converts them to an array of vibrating pins. The deaf are able to hear using a cochlear implant. A microphone detects sound and divides it into frequency bands. 22 electrodes within the cochlea stimulate the acoustic the acoustic nerve to provide sound patterns. For those who have lost muscle function in the limbs, researchers are implanting electrodes to stimulate the muscle. Sensors in the legs and arms feed back signals to a computer that coordinates the stimulators to provide limb motion. For those with high spinal cord injury, a puff and sip switch can control a computer and permit the disabled person operate the computer and communicate with the outside world.

• Journal of the Korean Wood Science and Technology
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• v.48 no.3
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• pp.271-282
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• 2020

Sewage treatment plants are social infrastructure of cities. The sewage distribution rate in Korea is reaching 94% based on the sewage statistics based in the year of 2017. In Korean sewage treatment plants, use of PAC (Poly Aluminum Chloride) accounts for 58%. It contains a large amount of impurities (heavy metal) according to the quality standards, however, there have been insufficient efforts to reinforce the standards or technically improve the quality, which resulted in secondary pollution problems from injecting excessive coagulant. Also, the increase in the use of chemicals is leading to the increases in the annual amount of sewage sludge generated in 2017 and the need to reuse sludge. As such, this study aims to verify the possibility of reusing sludge by evaluating the stability of heavy metals based on the injection of coagulant mixture during water treatment which uses the torrefield wood powder and natural materials, and evaluating the sedimentation and heating value of sewage sludge. As a result of analyzing heavy metals (Cr, Fe, Zn, Cu, Cd, As, Pb, and Ni) from the coagulant mixture and PAC (10%), Cr, Cd, Pb, Ni, and Hg were not detected. As for Zn, while its concentration notified in the quality standards for drinking water is 3 mg/L, only a small amount of 0.007 mg/L was detected in the coagulant mixture. Maximum amounts of over double amounts of Fe, Cu, and As were found with PAC (10%) compared to the coagulant mixture. Also, an analysis of sludge sedimentation found that the coagulant mixture showed a better performance of up to double the speed of the conventional coagulant, PAC (10%). The dry-basis lower heating value of sewage sludge produced by injecting the coagulant mixture was 3,378 kcal/kg, while that of sewage sludge generated due to PAC (10%) was 3,171 kcal/kg; although both coagulants met the requirements to be used as auxiliary fuel at thermal power plants, the coagulant mixture developed in this study could secure heating values 200 kal/kg higher than the counterpart. Therefore, utilization of the coagulant mixture for water treatment rather than PAC (10%) is expected to be more environmentally stable and effective, as it helps generating sludge with better stability against heavy metals, having a faster sludge sedimentation, and higher heating value.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.533-541
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• 2017

Agricultural landscape has many ecosystem service functions. However, the development of the horticulture complex has no consideration for environmental conservation. Therefore, we analyzed the priorities of ecosystem service functions required for the composition. The study was conducted in three stages. As a result of the first survey, 17 functions were selected to be improved. In the second survey, 12 functions were selected excluding 5 functions. Finally, 1. Measures for water purification, 2. Groundwater recharge plan, 3. Surface water storage space, 4. Flood control measures, 5. Vegetation diversity space, 6. Carbon emission reduction plan, 7. Aquatic insect habitat space, 8. Amphibian reptiles 9. Landscape and Waste Management, 10. Bird Species Space, 11. Heat Island Mitigation Plan, 12. Experience / Ecological Education Plan. We proposed the structure, capacity, flow rate, arrangement and form of the water treatment facility to improve water quality by improving the function. We proposed a reservoir space of 7-10% for groundwater recharge. The development of reservoir and storage facilities suitable for the Korean situation is suggested for the surface water storage and flood control measures. And proposed to secure a green space for the climate cycle. Proposed habitat and nutrient discharge management for biodiversity. We propose green area development and wetland development to improve the landscape, and put into the facilities for experiential education. The results of the research can be utilized for the development and improvement of the horticultural complex.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.74-80
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• 1996

This experiment was conducted to obtain the basis of degradation of remaining agricultural chemicals accumulated in upland soils of Honam district in Korea. The population. relative growth rate(RGR). chlorothalonil(TPN)-degradation ability and bacterialogical characteristics of TPN resistant strains were investigated in TPN levels of 0, 25, 50, 100 and $500{\mu}l/ml$ compared with Mancozeb. A number of TPN-resistant bacteria were differ in the area of examined and were decreased with higher levels of TPN. The resistance of bacteria was stronger in TPN than Mancozeb but the resistance of fungi was vise versa. RGR of bacteria in the culture was the highest at the level of $50{\mu}l/ml$ and the lowest in $500{\mu}l/ml$ of TPN. TPN-degradation ability of bacteda isolated in various TPN levels was varied : only 8 percentage of bacteria showed 75 percentage or more degradation ability. The higher the concentration in TPN resistance, the larger the number of strains carried great ability to decompose pesticide residues. The strains having higher decomposition ability was rod-shapes cells and senstive to heat. Analyses of the indol production, methyl red, and V-P test have given similar results, with negative reaction in all these strain, while the other biochemical characteristics were differ in the strains. Based on these, these strains might be classified into Pseudomonas sp., Corynebacterium sp., Acinetobacter sp. and Moraxcella sp.

• The Journal of the Petrological Society of Korea
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• v.21 no.3
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• pp.335-365
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• 2012

Fission-track (FT) thermochronological records from SE Korean Cretaceous-Paleogene granitic plutons in different fault-bounded blocks reveal contrasting cooling and later thermal histories. Overall cooling patterns are represented by a monotonous (J-shaped) curve in most plutons except some Cretaceous granites retaining a complicated (N-shaped) path due to post-reset re-cooling. Discriminative cooling rates over different temperature ranges can be explained for individual plutons with respect to relative pluton sizes, differences in initial heat loss depending on country rocks, and the presence and proximity of later igneous activity. Even within a single batholith, cooling times for different isotherms were roughly contemporaneous with respect to positions. Insignificant deviations in cooling ages from two different plutons in succession across the Yangsan fault may suggest their contemporaneity before major horizontal fault movement. The extent of later thermal rise recorded locally along the Yangsan and Dongnae fault zones were reached the Apatite Partial Stability Zone ($70-125^{\circ}C$), but did not exceed $200^{\circ}C$. Thermal alteration from fractured zones in the Yangsan-Ulsan fault junction may suggest a thermal reset above $290^{\circ}C$ resulting a complete reset in FT sphene age (31 Ma), caused by a tectonic subsidence in Early Oligocene. A consistency in FT zircon/apatite ages (24 Ma) may imply a sudden rapid cooling over $200-105^{\circ}C$, plausibly related to the abrupt tectonic uplift of the Pohang-Gampo Block including the fault junction in Late Oligocene. A remarkable trend of lower cooling ages for $300-200-100^{\circ}C$ isotherms (i.e., 19% for FT sphene and K-Ar biotite; 20% for FT zircon; 27% for FT apatite) from the east of the Ulsan fault (Pohang-Gampo Block) comparing to the west of the fault may be attributed to retarded cooling times from the Paleogene granites and also reflected by their partially-reduced apatite ages due to later thermal effects.