• Journal of Environmental Health Sciences
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• v.17 no.2
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• pp.78-94
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• 1991

The purpose of this study is to research the actual conditions of industrial accident patients and to produce worker satisfaction and a rational and effective counter measure pain. Direct interviews with 179 cases (in and out patients) were carried out during a three month period from April to July 1990, at six hospitals two general hospitals Sun Lin and Sung Mo in Po Hang, and four general hospitals in Taegu Kyung Pook University Hospital, Dong San Medical Center, Young Nam Medical Center and Catholic Hospital. The results of this study are summarized as follows: 1. Among the 179 cases, 51.6 % were male and 48.4 % were female. The two largest age groups were 30~39, 31.8 % and 20~29, 27.4 %. Among the 179 cases, 51.6% were married, the largest family number was 2 to 3, 41.1% and 4 to 5, 25.6%. Educationally, graduation from high school was the largest group, 46.4% among the patients, followed by middle school and primary school. The largest group income level was from 40~69만원, 45.2%. The largest group of patients who worked over 50 hrs. a week was 52.0%. The largest group of patients who worked less than 1 year was 44.7%, of the patients in work places of less than 100 people, 60.3% were injured and in work places of 100~299 people, 20.1% were injured. In manufacturing, the lagest group injured was 55.3%, the next group was transport, stroage, communication. The largest group of production workers injured was 40.2%. 2. The cause of injury in the largest group was facility problems, 33.5%. The next group was unsafe habits, 30.2% a lack of safety knowledge, 17.9% and insufficient supervision, 12.3%. The 30~39 year age group was head the highest number of injuries, 40.4% work places with more than 10 yeras of work, 44.4% work palces with more than 1000 people, 56.3% and mining accidents, 80.0%. Among these groups the highest cause of injury was due to facility problems. 3. The accident pattern showed machinery injuries 28.5% as the largest group, followed by falls & falling objects 17.3%, fire & electric 15.1%, struke by an object 14.5%, followed by overaction and vehicular accidents. The accident pattern showed 46.4 % among workers over the 50 year age group, workers in the 5~10 year group, 50.0 % places employing more than 1000 workers, 35.3 % : construction 73.7%, and construction workers 57.1%, among these fall & falling objects caused the greatest number of injuries. 4. The largest group of injuries was fractures 54.8%, trauma 14.5%, amputation 11.7%, open wound, and burns. The largest number of fractures occurred in people in the 30~39 year age group, 63.2 % over 10 years of work, 55.6% in work places of 300~400 people, 63.6% construction 63.2% and general workers 57.2 %. 5. The largest group of injuries was upper extremity 45.3%, lower extremity 24.0%, trunk 18.5 % and head or neck 12.2%. Of these groups, upper extremity injuries were the highest in those less 20 years old 75.0%, less than 1 years of work 59.5%, in work places of 500~999 people 60.0%, manufacturing 56.6 % and production workers 55.6%. 6. Periods of injury showed 34 people injured in September, to be the largest followed by October, 32 August, 22 people July, 19 people and the lowest December, 2 people. During the week, Friday had the largest group injured, 35 people followed by Saturday, 26 people and the lowest was Wednesday, 17 people, During the day 1400 hours had the largest group injured, 38 people followed by 800 hours, 31 people. 7. On a basis of 5 as the highest mark, the average, according to worker satisfaction showed facility safety 3.55, work environment 3.47, income 3.44, job 3.21 and treatment 2.98. 8. The correlation between general characteristics and injury showed that age was directly correlated to the duration of work(r=.2591) p<0.01, age was directly correlated to industry (r=2311) p<0.01, and the duration was directly correlated to occupation(r =.4372) p<0.001.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.2
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• pp.99-105
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• 1976

After investigation of soil characteristics the properties of a reclaimed marine soil (Gupo series) distributed along the southern coastal areas of Korea are summarized as follows: 1. Gupo soils distributed in the southern Ria coastal area are derived from rolling to hilly materials and are poorly sorted with less influences of river fluvial action. These soils have high content of sand compared with the broad fluvio-marine soils in the western coastal areas. 2. The morphological features of the poorly drained Gupo soils are greyish brown sandy loam with a few yellowish mottles in the surface horizon and are grey sandy loam with a few gravel in the sub-strata. The ground water table remains around 10-30cm below the surface. These soils, recently reclaimed younger deposits, do not show any evidence of illuviation. 3. The "n" value (about 0.8) of the Gupo soils indicates physically unripened soils. 4. pH value of these soils shows more than 8.0 throughout the profile. Organic matter contents are extremely low (around 0.5%) except 1.2 percent in the surface horizon. C.E.C. ranges from 7 to 9m.e/100g which is lower than average in the country. The ratios of extractable cations such as Ca, Mg, Na and K of the surface horizon are 20:7:4:1. Base saturation is more than 60%. Available phosphate content is very low that is less than 25 ppm. Electric conductivity of the soils at $25^{\circ}C$ ranges 7 to 12 mmhos/cm and increased with depth. 5. According to classification of soil based on physical ripening, the Gupo soils can be classified into "Unripe soils with half-ripe sub-soils". The soils could be classified into "Hydric Haplaquents" in the original of the 7th Approximation (1960), but into "Typic Haplaqents in the supplement of 7th approximation which the physical ripening condition is not clearly expressed. Soil Taxonomy, apparently the final version of the 7th approximation, defines the soils as "Haplic Hydraquents" that clearly show the condition of physical ripening as well as other properties. Other several classification systems applied do not describe physical ripening condition of the soils.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.4
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• pp.394-401
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• 2005

A nonthermal plasma-assisted fuel reformer was developed and the effects of operating variables on the performance of this reformer were studied. The $H_2$-rich reformed gas from the reformer was injected into a diesel engine under an idle condition and the effects of the amount of injected gas on the NO and soot reduction were investigated. It was found that with increasing electric power consumption, the degree of facility of ignition of the reforming reaction in the reformer could be enhanced. The performance of the reformer including $H_2$ concentration, $H_2$ recovery, and energy conversion was affected only by the O/C mole ratio. This was because the equilibrium reaction temperature was governed by the O/C mole ratio. With increasing O/C mole ratio, the $H_2$ recovery and energy conversion passed through the maximum values of 33.4% and 66%, respectively, at an O/C mole ratio between 1.2 and 1.5. The reason why the $H_2$ recovery and energy conversion increased with increasing O/C mole ratio when the O/C mole ratio was lower than $1.2{\sim}1.5$ appeared to be that the complete oxidation reaction occurred more enough with increasing O/C mole ratio in this low O/C mole ratio range and accordingly the reaction temperature increased. Whereas the reason why the $H_2$ recovery and energy conversion decreased with increasing O/C mole ratio when the O/C mole ratio was higher than $1.2{\sim}1.5$ appeared to be that the complete oxidation reaction was further advanced and the $H_2$ recovery and energy conversion decreased. As the weight ratio of reformed diesel to total diesel which entered the diesel engine was increased to $18.2{\sim}23.5%$, NO and soot reduction efficiencies increased and reached as values high as 68.5% and 23.5%, respectively.

• Journal of the Korean Magnetics Society
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• v.17 no.2
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• pp.81-85
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• 2007

MnTe layers of high crystalline quality were successfully grown on Si(100) : B and Si(111) substrates by molecular beam epitaxy (MBE). Under tellurium-rich condition and the substrate temperature around $400^{\circ}C$, a layer thickness of $700{\AA}$ could be easily obtained with the growth rate of $1.1 {\AA}/s$. We investigated the structural, magnetic and transport properties of MnTe layers by using x-ray diffraction (XRD), superconducting quantum interference device (SQUID) magnetometry, and physical properties measurement system (PPMS). Characterization of MnTe layers on Si(100) : B and Si(111) substrates by XRD revealed a hexagonal structure of polycrystals with lattice parameters, ${\alpha}=4.143{\pm}0.001{\AA}\;and\;c=6.707{\pm}0.001{\AA}$. Investigation of magnetic and transport properties of MnTe films showed anomalies unlike antiferromagnetic powder MnTe. The temperature dependence of the magnetization data taken in zero-field-tooling (ZFC) and field-cooling (FC) conditions indicates three magnetic transitions at around 21, 49, and 210 K as well as the great irreversibility between ZFC and FC magnetization in the films. These anomalies are attributable to a magnetic-elastic coupling in the films. Magnetization measurements indicate ferromagnetic behaviour with hysteresis loops at 5 and 300 K for MnTe polycrystalline film. The coercivity ($H_c$) values at 5 and 300 K are 55 and 44 Oe, respectively. In electro-transport measurements, the temperature dependence of resistivity revealed a noticeable semiconducting behaviours and showed conduction via Mott variable range hopping at low temperatures.

• Korean journal of applied entomology
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• v.16 no.2 s.31
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• pp.127-131
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• 1977

This experiment was conducted to evaluate the insect-proof netting, chemical sprays, application of attractants, fruit bagging and light trapping as the control methods of the fruit piercing moths in the orchards on reclaimed land in Sugyeri, Goksung, Chonnam Province, during June to October in 1976. The results are summarized as follows; 1. Insect-proof. netting effectively decreased fruit damage, compared as to the control, down to $9.4\%$ from $38.3\%$ in plum, $2.5\%$ from $53.0\%$ in peaches and $10.0\%$ from $29.0\%$ in grapes. 2. The control effects of chemicals varied significantly among the 7 insecticides tested: Deoclean, Naphthalene, and Thiometon were more effective to the fruit damages as low as $2.0\%,\; 3.6\%,\;and\;5.9\%$ respectively. while the fruit damage was rather high, $9.8\%$ for Demeton, $10.1\%$, for Takju +lead arsenate and $14.2\%$ for Padan. ,3. In the test with 7 attractants, the largest number of moths attracted and killed was 416.by Takju+brown sugar and the next was 307 by Takju+venegor while this number was 141 by mixed solution (see text) which is rather lower than expectation The fruit damage was lowest in Takju+honey and$5.2\%$, the next was $5.60\%$ for Takju+venegor and the highest was $12.0\%$, Takju alone. 4. Fruit bagging with polyethylene film effectively decreased the fruit damage from the inserts but brought about severe fruit rot and delay ripening. Meanwhile, paper bagging was less effective in preventing insects, resulting in $17.5\%$ fruit damage, however, gave no adverse effect other than slight Belay in ripening. 5. Light trapping was hardly expected to be a method of controlling these fruit piercing moths. However, the number of collected moths swarmed by electric light was 10.8 for can-descence, 0.95 for blue, and 0.22 for yellow light.

• Journal of dental hygiene science
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• v.9 no.1
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• pp.121-127
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• 2009

A comparative analysis was conducted through this study on tooth brushing and a use of auxiliary oral hygiene devices for oral hygiene for 287 S Health College students some of whom major dental hygiene and some of whom don't relate to the department, and then has drawn out the results as below. 1. Relating to the frequency of tooth brushing, 2-3 times a day was the utmost case in both departments(p < 0.05). 2. In use of toothbrush bristle, the students of dental hygiene department used medium bristle(51.2%), while the student of other department used soft bristle(51.5%)(p > 0.05). 3. In the term of tooth brush used, 2~5 months was the utmost case in both departments(p > 0.05). 4. In tooth- brushing method, all the student of both departments said they knew how to do it(p > 0.05). 5. In the acquisition of tooth brushing methods, the students of dental hygiene acquired it from dentistry 44.4%, and the students of other department from TV or Radio 47.5% (p > 0.05)which was a quite high rate. 6. In reference to recognition level on auxiliary oral hygiene devices, dental hygiene students said Yes 79.8%, and the other side students said No 63.9%(p < 0.05). In reuse of auxiliary oral hygiene devices, a great number of students of both departments said No (p < 0.05). 8. In reference to the chance to use auxiliary oral hygiene devices, 58.1% of dental hygiene students chose them with their own judgement, and 37.8% of other department students recommended by dentist's offices(p < 0.05). 9. Relating to the reason for not using auxiliary oral hygiene devices, 38.9% of the dental hygiene students said it's bothersome, and 56.7% of the other department students said they didn't know about these things(p < 0.05). 10. In the recognition level of dental floss, in knowing the way to use it, whether or not of using it, the students of both department showed a significant difference (p < 0.05). 11. In the recognition level of floss holder and the yes or not of using it, there was an insignificant difference(p > 0.05), while in understanding of it, there was a significant difference(p < 0.05). 12. Relating to the recognition level of electric tooth brush, yes or no of using it, there wasn't a significant difference(p > 0.05). 13. In the cognition level of rubber stimulator, yes or no of using it, there wasn't much difference, while in understanding to use it, there was a significant difference(p < 0.05). 14. In the understanding level of water pik, yes or not of using it, there wasn't a great deal of difference(p < 0.05), but in inquiry of whether or not of using it, there was no difference (p > 0.05), 15. In the understanding level of tongue scraper, whether or not of using it, there wasn't much difference(p > 0.05), but in understanding to use it, there was a great deal of difference(p < 0.05). 16. In the recognition of garglin, understanding of it, and whether or not of using it, the two departments didn't show a significant difference(p < 0.05).

• Journal of Technologic Dentistry
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• v.20 no.1
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• pp.37-49
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• 1998

The specimens used were Ag-25 Pd-15 Cu ternary alloy and Au addition alloy. These alloys were melted and casted by induction electric furnace and centrifugal casting machine in Ar atmosphere. These specimens were solution treated for 2hr at $800^{\circ}C$ and were then quenched into iced water, and aged at $350{\sim}550^{\circ}C$ Age- hardening characteristics of the small Au-containing Ag-Pd-Cu dental alloys were investigated by means of hardness testing. X-ray diffraction and electron microscope observations, electrical resistance, ergy dispersed spectra and electron probe microanalysis. Principal results are as follows : Hardening occured in two stages, i.e., stage I in low temperature and stage II in high temperature regions, during continuous aging. The case of hardening in stage I was due to the formation of the $L1_0$ type face-centered tetragonal PdCu-ordered phase in the grain interior and hardening in stage I was affected by the Cu concentration. In stage II, decomposition of the ${\alpha}$ solid solution to a PdCu ordered phase($L1_0$ type) and an Ag-rich ${\alpha}2$ phase occurred and a discontinuous precipitation occurred at the grain boundary. From the electron microscope study, it was conclued that the cause of age-hardening in this alloy is the precipitation of the PdCu ordered phase, which has AuCu I type face-centered tetragonal structure. Precipetation procedure was ${\alpha}{\to}{\alpha}+{\alpha}_2+PdCu {\to}{\alpha}_1+{\alpha}_2+PdCu$ at Pd/Cu = 1.7 Ag-Pd-Cu alloy is more effective dental alloy as ageing treatment and is suitable to isothermal ageing at $450^{\circ}C$.

• Korean journal of food and cookery science
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• v.16 no.6
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• pp.652-662
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• 2000

This study was performed to measure the mutagenicity of fish by cooking and storage. Mutagenicity of the fish extract was measured by Ames test(Salmonella typhimurium reversion assay with TA 100) in vitro and by micro-nucleus test in vivo. The fish samples screened in this study were white fish(Trichiurus, Croaker, Salted Croaker) and red fish(Saury pike, Mackerel, Yellowtail, Salmon). The number of revertants of red fish were significantly higher than that of white fish. And the mutagenicity of mackerel was higher than other red fish, so followed experiment was made by using the extract of mackerel. Mutagenicity of the samples cooked on microwave oven was the lowest, whereas there was no significant difference between the samples cooked on gas grill and the ones on electric grill. In the presence of S9 mixture, the methanol extract of mackerel showed 2∼4 times high values of mutagenicity in comparison with the extract without S9. The extract of mackerel cooked with various vegetable juices showed inhibitory effects on the mutagenicity in the order of green tea, ginger, and radish. Also, the number of revertants was increased in the stored samples. Mutagenicity of the samples stored in the refrigerator was higher than that of the freezer. In micronucleus test, the methanol extract treated with vegetable juice inhibited micro-nucleus formation in bone marrow by cyclophosphamide in the order of ginger, green tea, and radish. In TBA test, there was a tendency that TBA values were increased as the storage time increased. Also, the rancidity of sample were stored in the refrigerator was higher value than sample stored in the freezer. Samples cooked on microwave oven showed the highest value in rancidity. When the antioxidant effect of vegetable juice was measured by electron donating ability(EDA) of mackerel cooked with vegetable juice to DPPH, the samples treated with onion showed the highest value of EDA(%), and the samples treated with green tea, ginger and cabbage also showed the antioxidant effect.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.4
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• pp.72-81
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• 2013

The objective of this study was to verify whether SCB(Slurry Composting & Bio-filtration) system can be applied for the treatment of anaerobic digestion(AD) wastewater and also, to identify the most effective set among three filtration compost beds tested. Results can be summarized as these; (a) When AD wastewater was sprayed on the top of beds which were mainly composed of sawdust and/or other media and, subsequently, filtrates collected and analyzed, there were large drop in the values of Electric Conductivity(EC), Total Suspended Solid(TSS), Biochemical Oxygen Demand(BOD), and Chemical Oxygen Demand(COD). In contrast, Total Nitrgen(T-N) and Total Phosphorus(T-P) were progressively elevated. We consider these changes as positive if the filtrate are to be utilized as liquid fertilizer. (b) When three sets of filtration beds (T1, T2, T3) were compared for their effectiveness, no significant difference was found among them. These indicate that expensive sawdust can be replaced in part with cheaper media such as woodchip, rice husks, or others. (c) At early stage of operation (within 20 days), BOD in filtrates were maintained at high level probably due to the lack of microbial activity. During the same stage, T-N, T-P was at low level but, were elevated to higher levels thereafter. These data, when combined, indicate that the filtration system needs at least a couple of weeks for the optimized microbial functioning. (d) The temperatures of the experimental beds were progressively dropped as the experiment continued through the fall season, although filtration effectiveness was not noticeably influenced.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.349-354
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• 2009

In this study, a bubbling fluidized-bed reactor was used to study $CO_2$ capture from flue gas using a potassium-based dry sorbent. A dry sorbent, manufactured by the Korea Electric Power Research Institute, consists of 35% of $K_2CO_3$ for $CO_2$ absorption and 65% of supporters for mechanical strength. $H_2O$, a reactant of the carbonation reaction, was supplied in the reactor as a form of saturated water vapor at a given temperature. The experiment of the regeneration reaction was performed by raising up to a given temperature using $N_2$ as a fluidization gas. It was indicated that sorption capacity and regenerability of dry sorbents showed high-efficiency at $1.97\;mol\;H_2O/mol\;CO_2$ and $400^{\circ}C$, respectively. The regenerated sorbent samples were analyzed by TGA to confirm the extent of the reaction. When the regeneration temperature was $150^{\circ}C$, the regenerability of dry sorbents was about 60%, which was capable of applying those sorbents to a two-interconnected fluidized-bed reactor system with continuous solid circulation. The results obtained in this study can be used as basic data for designing and operating a large scale $CO_2$ capture process with two fluidized-bed reactors.