• The Journal of Korean Academy of Prosthodontics
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• v.58 no.3
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• pp.177-184
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• 2020

Purpose: The purpose of this study was to compare and evaluate the tensile bond strength of chairside reline resin to denture base resin fabricated by different methods (subtractive manufacturing, additive manufacturing, and conventional heat-curing). Materials and methods: Denture base specimens were fabricated as cuboid specimens with a width of 25 mm × length 25 mm × height 3 mm by subtractive manufacturing (VITA VIONIC BASE), additive manufacturing (NextDent Base) and conventional heat-curing (Lucitone 199). After storing the specimens in distilled water at 37℃ for 30 days and drying them, they were relined with polyethyl methacrylate (PEMA) chairside reline resin (REBASE II Normal). The subtractive and additive manufacturing groups were set as the experimental group, and the heat-curing group was set as the control group. Ten specimens were prepared for each group. After storing all bound specimens in distilled water at 37℃ for 24 hours, the tensile bond strength between denture bases and chairside reline resin was measured by a universal testing machine at a crosshead speed of 10 mm/min. The fracture pattern of each specimen was analyzed and classified into adhesive failure, cohesive failure, and mixed failure. Tensile bond strength, according to the fabrication method, was analyzed by 1-way ANOVA and Bonferroni's method (α=.05). Results: Mean tensile bond strength of the heat-curing group (2.45 ± 0.39 MPa) and subtractive manufacturing group (2.33 ± 0.39 MPa) had no significant difference (P>.999). The additive manufacturing group showed significantly lower tensile bond strength (1.23 ± 0.36 MPa) compared to the other groups (P<.001). Most specimens of heat-curing and subtractive manufacturing groups had mixed failure, but mixed failure and adhesive failure showed the same frequency in additive manufacturing group. Conclusion: The mean tensile bond strength of the subtractive manufacturing group was not significantly different from the heat-curing group. The additive manufacturing group showed significantly lower mean tensile bond strength than the other two groups.

• Korean Journal of Heritage: History & Science
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• v.53 no.2
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• pp.4-23
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• 2020

The purpose of this study was to explore the diversity of Korea's iron casting technology and to examine various casting methods. The study involved a literature review, analysis of artifacts, local investigation of production tools and technology, and scientific analysis of casting and cast materials. Bellows technology, or Bulmi technology, is a form of iron casting technology that uses bellows to melt cast iron before the molten iron is poured into a clay cast. This technology, handed down only in Jeju Island, relies on use of a clay cast instead of the sand cast that is more common in mainland Korea. Casting methods for cast iron pots can be broadly divided into two: sand mold casting and porcelain casting. The former uses a sand cast made from mixing seokbire (clay mixed with soft stones), sand and clay, while the latter uses a clay cast, formed by mixing clay with rice straw and reed. The five steps in the sand mold casting method for iron pot are cast making, filling, melting iron into molten iron, pouring the molten iron into the cast mold, and refining the final product. The six steps in the porcelain clay casting method are cast making, cast firing, spreading jilmeok, melting iron into molten iron, pouring the molten iron, and refining the final product. The two casting methods differ in terms of materials, cast firing, and spreading of jilmeok. This study provided insight into Korea's unique iron casting technology by examining the scientific principles behind the materials and tools used in each stage of iron pot casting: collecting and kneading mud, producing a cast, biscuit firing, hwajeokmosal (building sand on the heated cast) and spreading jilmeok, drying and biyaljil (spreading jilmeok evenly on the cast), hapjang (combining two half-sized casts to make one complete cast), producing a smelting furnace, roasting twice, smelting, pouring molten iron into a cast, and refining the final product. Scientific analysis of the final product and materials involved in porcelain clay casting showed that the main components were mud and sand (SiO₂, Al₂O₃, and Fe₂O₃). The release agent was found to be graphite, containing SiO₂, Al₂O₃, Fe₂O₃, and K₂O. The completed cast iron pot had the structure of white cast iron, comprised of cementite (Fe₃C) and pearlite (a layered structure of ferrite and cementite).

• Parasites, Hosts and Diseases
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• v.28 no.4
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• pp.241-252
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• 1990

In a basic attempt to develop the prophylactic and therapeutic measures on intestinal giantcystic disease of the Israel carp, C), prinks carpio nudum, the effects of physical and chemical factors on viability or survival of the spores of Thelchcnellus kiteuei were checked in vitro by means of extrusion test on the polar filament. When the fresh spores suspended with 0.45% and 0.9% scdium chloride solution and distilled water were laid at $5^{\circ}C$ and $28^{\circ}C$ for short terms, the extrusion rates increased until the 3rd day, meanwhile when son;e of them were suspended with Tyrode's solution at $-70^{\circ}C$ the rates increased gradually until the 8th day. Viabilities of the spores suspended with 0.9% saline and added antibiotics to the suspension at $5^{\circ}C$ for long terms lasted for 997 days and 1, 256 days (presumed values) at maximum, respectively. The spores suspended with distilled water at $28^{\circ}C$ for long terms survived 152.4 days, but the spores suspended with Tyrode's solution at $-70^{\circ}C$ for long terms showed almost the same viable pattern as early freezing stages up to 780 days. The spores suspended with Tyrode's solution, frozen at $-70^{\circ}C$ and thawed at $5^{\circ}C$, showed the highest rate of extrusion of the polar filament. In the case of frozen spores, the extrusion rates during heating tend to become higher in accordance with the increase of frozen period, and the critical points of 180 day-frozen spores to be killed were generally 78.5 hr. at $60^{\circ}C$, 23.4 hr. at $70^{\circ}C$, 189.1 min. at $80^{\circ}C$ or 10.5 min. at $90^{\circ}C$. The longer the spores were frozen, the more time was needed for the death of spores after thawing; 20 days-17.4 days, 100 days-33.2 days, and 400 days-37.8 days. The longer the spores were frozen, the more time was needed for the death of spores at a conventional when they were dried air drying condition, 540 days-23.5 days, 160 days-21.0 days, and 20 days-14.4 days. On the other hand, the longer the spores were frozen, the more spores were dead rapidly when they were irradiated with 10W UV-ray; 100 days-26.0 hr, 300 days-21.9 hr, and 540 days-13.9 hr. The time needed for killing 200 days-frozen spores by various disinfectants at 1, 000 ppd was 5.2 min. by calcium oxide, 10.4 min. by potassium permanganate, 27.8 min. by malachite green and 14.3 hr. by formalin. Transient inhibitory effects of the extrusion of the polar filament were observed by various antiprotozoal and antifungal agents in the descending order of ketoconazole. metronidasole and dapsone. The above results presume that full drying, followed by spraying CaO and maintaining sunny condition for a few days on the concrete bottoms of knish farm may be an effective method for the prevention of intestinal giant.cystic disease.

• Journal of the Korean Society of Food Culture
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• v.15 no.1
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• pp.59-68
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• 2000

This survey investigated on the degree of acknowledgment, intake frequency and using methods of wild grasses of the residents in Kyeonggi, Kangwon, Chunnam, Chungbook, Kyeongnam & Cheju area. The results were as follows: 1. An answer that impression of wild grasses is 'nature food' was the highest(42.6%). It was founded that interest of nature food has been increasing. 2. It has been shown that the most common method for elimination of astringent taste is to blanch and then wash several times with water.(62.9%) 3. The most common obtaining routes was traditional market. It has been shown that rate of gathering in the fields is higher in rural community and the group of over 60 years old than that of urban community and the other groups. 4. In rural area, people(28.7%) ate wild grasses more frequently than in urban area. Family with the old and the group of over 40 years old eat wild grass often. 5. More than 95% of answerers were familiar with the names of wild grasses, codonopsis lanceolata, chinese bellflower, braken, mugwort, wild rocambole and edible shoots of a fatsia & Korean lettuce are known to them with over 88.6%, 85.1% respectively. Frequently eaten wild grasses were braken, chinese bellflower, wild tocambole, codonopsis lanceolata, mugwort and korean lettuce orderly. But in Chunnam & Kyeongnam, they were braken, chinese bellflower, mugwort, wild rocambole and Korean lettuce orderly. 6. Wild grasses eaten with rice were total 25 species, and mugwort had the highest usage rate with 41.9%. Mugwort was used for $D'{\breve{o}}k$(rice cake)(77.8%), T'wigim $J{\breve{o}}n$(deep fat fried dish swallow fat fried dish)(50.1%) and liquor(4.6%). In the cooking of Guk(soup), Chigae(stew), Sengch'ae(raw vegetable) and kinds of wild grasses for Namul(cooked seasonal vegetable) & Bokkum(saute) are the most various with 58 species, especially braken was most commonly used for saute. Sedum & Korean lettuce were the common ingredients of Kimch and codonopsis lanceolata was used in liquer & Jangachis(pickle) with 40%, 46% each. Chinese bellflower was used with the most variable cooking method. 7. 43 species of wild grasses were stored by blanching and drying, and braken had the highest rate(32.3%) then aster scaber, flowering fern, Pimpinella brachycarpa, mugwort and ligularia orderly.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.4
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• pp.446-454
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• 2008

The traditional Korean drink "Jehotang", which is one of the most commonly prescribed drugs for treatment of the heat stroke accompanied by high fever, severe sweat and thirst, it is effective far quenching thirst strengthening the stomach, stopping diarrhea and regulating intestinal function. It is also known to play a role in activating the growth of useful microbes in the intestine and in multiplying intestinal immune cells. Thus, this study investigated all aspects of the drink in an effort to develop a new functional beverage. In the course of this study, the analytical research into the literature concerning Jehotang an error in the secrets of preparing the drink. The Japanese apricot, which was given the botanical name, "Prunusmume", should only be used with the flesh (scientifically referred to as "Fructusmume"), which is fumigated with straw fire before drying. and the seed should be thrown away. The honey should only be used after it is heated with a gentle fire, before removing the white foam that farms on its surface to make the "Yeonmil". Two kinds of cooking processes were found in the ancient literature. One procedure boiling down the powered Fructus mume mixed with the Yeonmil, while the other procedure involved preparing the Fructus mume's water by adding water to it and blending the water with the Yeonmil and the rest of the raw ingredient before boiling them down. The current procedure, in which the cooking is done in a double boiler, has been widely adopted to its simplicity. The finished Jehotang is put in porcelain, kept at room temperature, and consumed after mixing with cold water.

• Journal of Korean Medical classics
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• v.6
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• pp.89-130
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• 1993

Huh-joon's medical thoughts shown on his medical book of the Doog-Eui-Bo-Kham can be summerized as follows. 1. The general trend of medical science in Koryo dynasty is that much more interests were concentrated upon the books about curative means rather than upon the books about theoretical knowledge of medical science. With the development of Hyang Yak(鄕樂) (the term referring either various kinds of domestic medical stuffs such as herbs or the curative methods using those stuffs) and the writing of books on Hyang Yak, independent medical science of the nation's own was established in late Koryo dynasty. And the national medical science was continuously further developed until early Choson dynasty. Briskly-expanded mutual exchanges with China in early Choson dynasty provided Choson opportunities to import Chinese medical science and to examine it. Under this circumstances, he wrote the Dong-Eui-Bo-Kham. 2. As we look over the preface and Chip-Rae-Muo(集例文), we can find the characterstic of Doog-Eui-Bo-Kham is that the philosophical theory of Taoism was quoted in explaining the principles of his medical science and that the main idea of Naekyuog is the basis in explaining the way of curing diseases. 3. 83 kinds of medical books were quoted in the Doog-Eui-Bo-Kham. Besides, as many as 200 kinds of books including Tao-tzu's teaching books(道書), history books(史書), almanac(曆書), and Confucius' teaching books(儒家書籍) were quoted in total. Naekyuog and Eue-Hak-Ip-Mun, Dan-Kye-Sim-Bup were the most frequently quoted books among them. 4. Huh-Joon's medical thoughts about health care were like these. 1) The reason why Huh-Joon regarded the idea of health care as of great importance was that he laid much more emphasises on the preventive medicines rather than on the remedial medicines. The direct reason was that he was greatly influenced by profound knowledge of Taoist's study of discipline and who participated in the editing the books from the beginning. 2) Huh-Joon's outlook on human body started from the theory of "Unity of Heaven and Man"(天人合一論), which implied man was a kind of miniature universe. In addition to that, he largely theory of essence(精), vital force(氣), and spirit(神) which were regarded very important as the three most valuable properties in Taoism. However, he took his medical ground on practical and pragmatic idea that he did not discuss fundamental essence(元精), fundamental vital force(元氣), and fundamental spirit(元神) which were given by Heaven from the received only the theory of essence, vital force, and spirit which were acquired after birth and worked mainly on realistic activity of life. 3) Huh-loon accepted Do-In-Bup(導引法) sharply as a method to prevent and cure diseases. 5. Huh-loon's medical thoughts on remedial aspects are as 1) Naekyung was considered so important in Dong-Eui-Bo-Kham that not only each paragraph was begun with the Quotations from Nackyung but also the edited order of the content of the book the same with that of Naekyung. And differently from the former korean medical books he accepted at large and recorded the theories of the four noted physicians of the Geum-Won era(金元四大家) by Dong-Eui-Bo-Kham. 2) For the first time, Huh-Joon introduced the theory of Un-Ki (運氣論) in the Dong-Eui-Bo-Kahm. However, he accepted it as a pathological function of human body but he did not apply physical constitution, physiological function, pathological function, and remedial methods. 3) Huh-loon liked to use Hyang Yak that he recorded korean name of Hyang Yak(鄕名), places of the production(産地), the time of collecting(採取時月), and the way of drying herbs(陰陽乾正法) in the remedial method of a single medicine prescription for diseases at the end of each paragraph. By doing so, he developed, arranged, and revived Hyang Yak. 4) He believed that since the natural features of China were different from those of Korea the reasons of being attacked with its remedial methods couldn't be the same with different from Chinese medical books which primarily focused on paralysis and the injury of the cold has his own structure in his book that he founded independent science of this nation. He consulted enormous documents He discovered and wrote the theory and therefore concrete methods for diseases so that the book hadthe principles of outbreak of diseases(理), methods of cure(法), prescription(方), and a single medicine prescription(藥) and set system of medical science in a good order. By doing so, he and pragmatic development of medical science.

• Clean Technology
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• v.19 no.3
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• pp.264-271
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• 2013

In this study, we optimized the removal condition of contaminants attached on the scrap surface to recycle the scrap generated from the Zr alloy tube manufacturing process back to the nuclear grade. The main contaminant is remnant of watersoluble cooling lubricant that is used in the pilgering manufacture during the tube production, and it is assumed to be compressed and carbonized on the surface of tube. Zirlo alloy tube of ${\phi}9.50mm$, which has high occurrence frequency of scrap, was selected as the object to be cleaned, and cleaning abilities of reagents were evaluated by measuring the characteristics of contaminants remained and by analyzing the surface of the tube after cleaning process. For evaluation of each cleaning agent, we selected two types of sodium hydroxide series and three types of potassium hydroxide series. Furthermore, to confirm dependence on tempe-rature and ultrasonic intensities, cleaning at the room temperature, $40^{\circ}C$, and $60^{\circ}C$ was conducted, and results showed that higher the cleaning temperature and higher the ultrasonic intensity, better the cleaning effect. As a result of the bare-eye inspection, while the use of sodium hydroxide provided satisfactory condition on the tube surface, the use of potassium hydroxide series provided satisfactory condition on the tube surface only when the ultrasonic intensity was over 120 W. In the cleaning effect analysis using the gravimetric method, cleaning efficiency of sodium hydroxide series was as high as 97.6% ($60^{\circ}C$, 120 W), but since the tube surface condition was poor after the use of potassium hydroxide, the gravimetric method was not appropriate. In the analytical result of surface contaminants on the tube surface, C, O, Ca, and Zr were detected, and mainly C and O dominated the proportion of contaminants. It was also found that the degree of cleaning on the tube affected the componential ratio of C and O; if the degree of cleaning is high, or if cleaning is well-conducted, the proportion of C is decreased, and the proportion of O is increased. Based on these results, optimal cleaning for application in the industry can be expected by categorizing cleaning process into three steps of Alkali cleaning, Rinsing, and Drying and by adjusting cleaning parameters in each step.

• Journal of Korean Academy of Nursing
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• v.24 no.4
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• pp.597-615
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• 1994

This study is designed to facilitate the creation of home environment conducive to the family taking care of chronic bed-ridden patients with more effective method. The need for this study has emerged against the background of marked changes in the structure of ailments and causes of death, resulting in the number and plights of chronic bed-ridden patients as well as of a rapid increase in demand for medical care and resulting premature discharge. Keeping these in mind, this study focused on home-wards where the majority of chronic bed-ridden patients are being cared for. Despite. their overriding importance, home-words are less than efficient in caring (or chronic bed-ridden patients. These circumstances require the designing of home-wards that can offer greater comfort to patients and at the same time make things easier for caregivers, on the basis of an overall analysis of patients' life and home - ward situation. According1y this study adopted a Participant Observation Method derived cultural anthropology, Toward this end, 3 patients were chosen as subjects of this study for intensive interviewing and participant observation. In the process of this field re-search efforts were made to collect emprical data, that is, to faithfully record the words of the subjects and their caregivers for analysis and interpretation. The findings of these analyses are as follows. Firstly, the chronic bed-ridden patients are mostly being taken care by close family members. Secondly, a room for the exclusive use of the patient, floor, kitchen, bathroom and multipurpose space were found to be necessary for proper caring of the patient. These spaces were respectively used with a view to 1) accomodating the patient as well as caregivers' activities, 2) keeping general and medical supplies and other appliances for patient's care and drying the patient's washing, 3) preparing and keeping the patient's foods and beverages, 4) keeping the supplies necessary for cleaning the patient's body and treating the patient's eliminations, 5) washing the patient's clothes, underwears and bedclothes. The patient's room in turn is subdivided into six portions in terms of uses : specifically the places for accomodating 1) the patient, 2) medical supplies, 3) medicines, 4) linens St clothes, 5) bedclothes and, 6) diapers. Thirdly, the activities of the caregiver are subdivided into seven key areas : hygiene, exercise, diet, elimination, therapeutic nursing, prevention of sore, and other activities. Each area is further classified into several different activities of caring. These activities we mainly carried out in the patient's room. Fourthly, the supplies for caring the chronic bed-ridden patient is divided into two large domains : medical and general supplies. Finally, three main problems areas were found in this study on the part of caregivers, that is, sore prevention, hygiene problem related frequent urination / defecation, the caregiver's physical, psych ological and emotional burden. In consideration of the aforesaid problem areas, a model home-ward was developed in this study. The newly-developed model has been found to have the following six advantages. Firstly, the time and effort required for maintaining the patient's hygiene are reduced, thus relievins the caregiver's physical and psychological bur-den. Secondly, the patient's hygiene can be maintained in satisfactory conditions, because the patient's eliminations are more easily removed. Thirdly, skin irritations caused by the patient's eliminations were remarkably reduced and so were the patient's sores due to moisture and bacteria. Fourthly, the home-ward have a tilt-table ef-fect thanks to the inclining room floor. This improves the patient's cardiovascular function as well as constantly changes pressed skin areas and thus prevents sores. Fifthly, improved shelf arrangements help make the best use of patient's supplies. Sixthly, the trouble of continuously changing clothes, underwears, diapers & bedclothes is remarkably reduced simply by covering the patient with cotton sheets when laid in bed. This is espected to cut down expenses by reducing the comsumptions of diapers and other disposable supplies.

• Journal of Korean Society of Forest Science
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• v.78 no.3
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• pp.314-322
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• 1989

For the improvement of nursery condition and the study of eco-physiological characteristics of Pinus koraiensis(2-2) seedlings, the primary productivity was investigated and the growth characteristics and their correlationship were analyzed from May to September in 1987. Seedlings used in this study were grown at the nursery of Experimental Forestry of Kyung Hee Univ. The installation of experimental plots were divided into control plot (100%), 63%, 37% and 19% relative light intensity, and each relative light intensity plots were split into $15{\times}15/m^2$, $12{\times}12/m^2$, $9{\times}9/m^2$ and $6{\times}6/m^2$ plnting density by randomized black design method. To take into account the edge effect of plant population, material were selected from each plot by random sampling at 30 days interval. Each sampled material was divided into leaf and stem drived in a drying oven at the temperature of $85^{\circ}C$ until it had constant weight and weighed. and leaf area was surveyed. Growth analysis for RGR and NAR was done by Blackman method and correlation coefficient were investigated between RGR and NAR by analyzing the dry matter production and growth characteristics of the material, cultivated on the experimental nursery under the condition of different treatment the obtained result were as follows : 1. The increasing rate of dry matter was similar at early stage of growth, but not at late stage. 2. Leaf area growth was the maximum value at 63% relative light intensity and the minimum at 19% RLI 3. The value of RGR was the highest on June under $6{\times}6/m^2$ planting density in 63% relative light intensity, the lowest on September under $12{\times}12/m^2$ of 19% relative light intensity. 4. The change NAR decreased in early stage of growth, while it increased on August and September, The value of RGR on June under $6{\times}6/m^2$ planting density in 100 light intensity was the highest, and on September under $12{\times}12/m^2$ planting density in 19% relative light intensity was the lowest. 5. Regression and correlation between RGR and NAR showed significantly positive.

• Restorative Dentistry and Endodontics
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• v.35 no.5
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• pp.335-343
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• 2010

Objectives: To compared the effect of different levels of moisture of root canal on the sealing ability after filling with four different types of sealer. Materials and Methods: Single-rooted teeth (n = 90) instrumented to and apical size of 0.06 / 45 were randomly assigned to 12 experimental groups (n = 7 per group), positive/negative control groups (n = 3 per group). The teeth of the experimental groups (a. DRY; b. PAPER POINT DRY; c. WET) were obturated with sealer (Group 1-3: Sealapex; Group 4-6: AH plus; Group 7-9: Tubuli-seal; Group 10-12: EndoRez) and warm vertical compaction method. After 7 days in $37^{\circ}C$, 100% humidity, the coronal-to-apical microleakage was evaluated quantitatively using a glucose leakage model. The leaked glucose concentration was measured with spectrophotometer at 1, 3, 7, 14, 21, and 30 days. Data were recorded ad mmol/L and statistically analysed with the two-way ANOVA and Duncan test (p = 0.05). Results: Throughout the experimental period Tubuli-seal/WET (Group 9) showed the highest mean cumulative glucose penetration (178.75 mmol/L), whereas AH plus/DRY (Group 4) had the least (20.78 mmol/L). Conclusions: The results of this study demonstrated that the moisture condition of root canals at the time of obturation and the type of sealer that was used had a significant effect on leakage and sealing ability. Thus drying procedure according to sealer types is a critical step and should not be missed in endodontic treatment.