• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.20 no.4
• /
• pp.316-333
• /
• 1998

Obstructive sialadenitis of major salivary glands is a common entity that occurs either in sialolithiasis or in foreign-body obstruction of the excretory ducts. This is characterized histologically by the presence of duct-like structural groups in a highly fibrotic stroma. Although the pathologic features are well recognized, the various cell types involved in the atrophy and subsequent regeneration of the obstructed salivary gland have been controversial. For this reason, an animal model of obstructive sialadenitis that induced atrophy in the salivary gland was used. Experimental study was performed to observe changes of submandibular gland in rabbit and apply the results to clinical activity. Forty-five rabbits each weighing about 3Kg were used and divided into control and experimental group. In the experimental group, ducts of submandibular gland was ligated and cutted divided into each twenty rabbits. Rabbits were serially sacrificed on the 3rd, 5th, 14th, 30th day of experiment. The submandibular glands were dissected out at sacrifice and stained with H&E, MT, immunohistochemical stain and the histological examinations were carried out under the light and transmission electron microscope. After examination and comparison of all specimens, the results of this study were as follows: 1. In the features of H&E stain, moderate infiltration of inflammatory cell were present at 3rd day of experiment. The features of ductal metaplasia was observed after 7th day in the ligation group and destructive changes was continued. In the cutting group, atrophic changes were less severe than ligation group but the small ductule were separated from stroma after 7th day. 2. In the feature of MT stain, apposition of connective tissue was increased in all group, more active in ligation group. 3. In the features of immunohistochemical stain, ligation group showed increased PCNA positive response at 7th day and the higher activity of duct cells was observed. Severance group showed more PCNA positive response than ligation group at 30th day. 4. In TEM features, ductal metaplasia was started at 7th day and degenerative change with margination of nucleus had been severe. Although ductal metaplasia was seen in the severance group, more numerous granule in different size was founded than ligation group. From above results, degenerative change was identified with ductal metaplasia, apically apposition of granule, r-ER destruction in ligation group. Severance of duct elicit degenerative change of grandular cells but the change was less severe than ligation group and more PCNA positive cell was founded at acinar cell.

• Journal of Korean Library and Information Science Society
• /
• v.35 no.3
• /
• pp.79-94
• /
• 2004

This research studied the preservation treatment of the papered literature the national treasure 745-9 $\ulcorner$Keumganggyung-samgahae$\lrcorner$, discovered in 1995 from the Four Devas of Borimsa Buddhist Temple at Jangheung County, in the viewpoint of the bibliography. The overall features of the $\ulcorner$Keumganggyung-samgahae$\lrcorner$ were of 25.3cm width, 38.9cm height 1.5cm depth, 58 pages and of high-fine yellow-brown colored reef paper. The book was ruined physically in the shape and color. The covers of the book were deeply stained by the permeated rain and some internal pages were changing into brown color by corrosion. The treatment policies were； maintaining the status quo and capable repeated treatment. And the preservation treatment was done in the sequences of 1) 1st cleaning process, 2) repairing and correcting, 3) 2nd cleaning and preservation 4) cutting, binding the book and making the envelope and wood box. The post-preservation features of $\ulcorner$Keumganggyung-samgahae$\lrcorner$ were； total 64 pages and the size being 25.8 cm width 39.4cm of lenght, and 1.9cm of depth.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2002.07a
• /
• pp.25-37
• /
• 2002

The most important industrial application of gamma radiation in characterizing green compacts is the determination of the density. Examples are given where this method is applied in manufacturing technical components in powder metallurgy. The requirements imposed by modern quality management systems and operation by the workforce in industrial production are described. The accuracy of measurement achieved with this method is demonstrated and a comparison is given with other test methods to measure the density. The advantages and limitations of gamma ray densitometry are outlined. The gamma ray densitometer measures the attenuation of gamma radiation penetrating the test parts (Fig. 1). As the capability of compacts to absorb this type of radiation depends on their density, the attenuation of gamma radiation can serve as a measure of the density. The volume of the part being tested is defined by the size of the aperture screeniing out the radiation. It is a channel with the cross section of the aperture whose length is the height of the test part. The intensity of the radiation identified by the detector is the quantity used to determine the material density. Gamma ray densitometry can equally be performed on green compacts as well as on sintered components. Neither special preparation of test parts nor skilled personnel is required to perform the measurement; neither liquids nor other harmful substances are involved. When parts are exhibiting local density variations, which is normally the case in powder compaction, sectional densities can be determined in different parts of the sample without cutting it into pieces. The test is non-destructive, i.e. the parts can still be used after the measurement and do not have to be scrapped. The measurement is controlled by a special PC based software. All results are available for further processing by in-house quality documentation and supervision of measurements. Tool setting for multi-level components can be much improved by using this test method. When a densitometer is installed on the press shop floor, it can be operated by the tool setter himself. Then he can return to the press and immediately implement the corrections. Transfer of sample parts to the lab for density testing can be eliminated and results for the correction of tool settings are more readily available. This helps to reduce the time required for tool setting and clearly improves the productivity of powder presses. The range of materials where this method can be successfully applied covers almost the entire periodic system of the elements. It reaches from the light elements such as graphite via light metals (AI, Mg, Li, Ti) and their alloys, ceramics ($AI_20_3$, SiC, Si_3N_4, $Zr0_2$, ...), magnetic materials (hard and soft ferrites, AlNiCo, Nd-Fe-B, ...), metals including iron and alloy steels, Cu, Ni and Co based alloys to refractory and heavy metals (W, Mo, ...) as well as hardmetals. The gamma radiation required for the measurement is generated by radioactive sources which are produced by nuclear technology. These nuclear materials are safely encapsulated in stainless steel capsules so that no radioactive material can escape from the protective shielding container. The gamma ray densitometer is subject to the strict regulations for the use of radioactive materials. The radiation shield is so effective that there is no elevation of the natural radiation level outside the instrument. Personal dosimetry by the operating personnel is not required. Even in case of malfunction, loss of power and incorrect operation, the escape of gamma radiation from the instrument is positively prevented.

• Journal of Society of Preventive Korean Medicine
• /
• v.17 no.1
• /
• pp.181-197
• /
• 2013

Objectives : This study aimed to assess the differences in treatment behavior by reviewing data of a medical institution that studies treatment behavior in URI and assessing the treatment efficacy in Korea. Methods : We analyzed the behavior of medical customers and providers of upper respiratory infection medications using the NPS published by the Health Insurance Review Assessment Service. We created an operational definition for complications, and confirmed the difference in complication distribution between medical specialties. We also performed a multivariate analysis using a mixed model to elucidate the factors influencing the occurrence of complications. Results : The outcomes of analyzing factors to influence the difference in practice patterns of the diagnosing URI between the physicians are as follows; (1) Analysis of antibiotics prescriptions rate showed significant difference from medical departments (pediatrics; 49.7%, internal medicine; 54.2%, otorhinolaryngology; 69.6%, family medicine; 61.6%, general surgery; 57.5%, p<0.001). Analysis of steroid prescriptions rate showed significant difference from medical departments (pediatrics; 3.8%, internal medicine; 4.5%, otorhinolaryngology; 5.4%, family medicine; 3.0%, general surgery; 11.2%, p<0.001). (2) In patients who visited medical institutes with the common cold, the complication distribution differed according to the medical specialty, which suggests that specific complications arise depending on the particular medical specialty (p<0.001). (3) Moreover, through multivariate analysis, we found that the complication rate is higher in clinics than in hospitals, depending on the institute's size. (p<0.001; odds ratio of 4.67 in clinics than in hospitals, 95% CI 2.66-8.21) Conclusions : We observe a deviation between the behavior of patients diagnosed with URI and medication providers. This may arise from the interaction between providers and consumers, wherein the complications are associated with the choice of outpatient department and the prevention of cutting incentives. These findings suggest that the health policies should be improved to prevent inappropriate medical practice in the treatment of pediatric URI.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2011.10a
• /
• pp.39-41
• /
• 2011

The recycling rate of recovered paper in Korea is the highest in the world, 92%, but remanufacturing yield is low due to the extremely poor quality of the paper. The poor quality, in turn, influences to the reject amount in deinking process. To increase the yield of old newspaper recycling process, hydrophobic degree of inorganic pigments of deinking stock must be reduced. To determine the hydrophobicity, Pitch Potential Deposit Tester (PDT) was newly designed and applied with respect to the SB latex property of various quality used in Korea; its hydrophobic degree according to Tg, gel content, charge and particle size of latex and optimum designing condition of SB latex. And below are the conclusions: 1. The reason of excessive reject from old newspaper deinking process for total amount of printed ink is loss of inorganic pigments. When lipase, a biochemical catalyst, was applied with the purpose of preventing inorganic pigments loss about more than 70% of total reject weight and promoting hydration of pulp for deinking, deinking process yield of pre flotation secondary stage increased remarkably without any changes of deinking efficiency. 2. Lipase improved deinking stock by cutting ester linkage on surface of hydrophobic materials to promote its hydration. From this, it reached the conclusion that hydration degree of stock exercises significant effect on flotation deinking process yield. 3. Inorganic alkali promotes hydration of deinking stock. But there have been needs for more fundamental measures other than inorganic alkali of promoting hydration for yield improvement. For this, this study intended to find out reasons of chemical properties change on surface of hydrophobic material by change of pH. 4. Pitch Deposit Test (PDT) was performed for understanding principle of why surface of coating flake from OMG is hydrophobic and why it becomes hydrophilic when pH of stock is alkaline. As a result of this test, it is determined that swelling property by change of pH of latex film, which were used as coating adhesive is the reason for hydrophobic change. 5. Hydrophilicity of coating flake increased with hydrophilic pigments. And as more of SB Latex adhesive was used and higher of calcium hardness of stock became, its hydrophilicity decreased. SB Latex adhesive film is reformed by mechanical friction. For having hydrophilicity under neutral pH, strong bruising action such as kneading is required. 6. Because swelling of adhesive film decreases as Tg of SB latex gets lower and mean diameter gets smaller, it shows hydrophobicity under neutral pH. This lowers hydrophilicity of coating flake, which leads to easy elimination with flotation reject on DIP process. Therefore, for improving future flotation yield, it is necessary to develop to use eco-friendly clean SB latex by raising Tg and increasing mean diameter for recycling, and as a result, to reduce excessive loss of coating flake as a reject from deinking process.

• Korean Journal of Oriental Medicine
• /
• v.15 no.2
• /
• pp.51-61
• /
• 2009

Objective: Much has been known that the systematical theory of acupuncture was developed from stone needle as therapeutic tools for orthopedic diseases in ancient times. Stone needle is very old therapeutic method like moxibustion and has been recognized that it was developed since the Stone Age in China so far. In the present study, it was examined for the origination and formation of stone needle based on stone relics of the Stone Age in Korean Peninsular, the medical and geographical literatures. Materials and methods: The facts of stone needle was examined and arranged on the ancient medical or geographical literatures such as The Yellow Emperor's Canon Internal Medicine, Shanhaijing as an ancient geographical book, etc. The clan societies and family related to an origination of stone needle was chased together with their cultural characteristics and origination. The stone relics which have been digged out of historic sites in the North-East Asia were examined for a relevance to stone needle. Results: In The Yellow Emperor's Canon Internal Medicine, it was referred to the stone needle that originated from a fishery zone related to the east coast district in North-East Asia. Through the examination of Shan Hai Jing as an ancient geographical book and its historical reviews, a Go-yi clan society who keep Go's family tree dealt well with the stone needle and jewels including jade in the North-East Asia before the publication periods of The Yellow Emperor's Canon Internal Medicine, and is comprised in the culture of Dong-yi clan society but not the Chinese culture. The obsidian stones, which have been digged out of historical sites in the North-East Asia since the Stone Age, are originated from volcanic areas combined with seashore that seems to be Baekdu mountain district in Korea and Kyushu district in Japan. Furthermore, obsidian stone tools which were found out at Laodung peninsula and the Korean peninsula are archeologically similar to the stone needle with regards to the shape, size and dual-use. In addition, specific obsidian stone tools have been used in orthopedic surgery as well-crafted obsidian blades have a cutting edge up to five times sharper than high-quality steel surgical scalpels. Conclusion: The origin of obsidian stone needle is well corresponded to the explanation about that of the stone needle. It is suggested that the stone needle which influenced in completion of acupuncture and Meridian theory in China seems to be an obsidian stone, and distribution of obsidian stone needle has been closely connected to Dong-yi clan society which are lived in the North-East Asia including Baekdu-mountain district.

• Korean Journal of Food Science and Technology
• /
• v.36 no.2
• /
• pp.276-282
• /
• 2004

Barley flakes were developed by extrusion cooking using broken kernels, by-products of the barley pearling process. Broken kernels from both non-waxy and waxy barley broken kernels were sufficiently gelatinized at the barrel temperature of over $100^{\circ}C$ and the moisture content of broken kernels of over 35%. Cutting and flaking roll separating properties of pellets prepared from non-waxy barley broken kernels were better than those of waxy barley broken kernels. Characteristics of pellets prepared by extrusion cooking in different mixing ratios of non-waxy and waxy barley broken kernels were investigated. As the mixing ratio of waxy barley broken kernels increased, RVA peak viscosity, apparent viscosity, and yield stress of prepared pellets decreased, while flow behavior index increased. As the mixing ratio of waxy barley broken kernels increased, compressive strength and bulk density of deep-fat fried flakes drastically decreased, and the size of air cells on cross-section increased, and thickness of cell-constituting bodies decreased. Sensory evaluation results showed that acceptability for texture and taste of flakes inclosed as the mixing ratio of waxy barley broken kernels increased, and optimum mixing level of waxy barley broken kernels appeared to be 30-40%.

• Membrane Journal
• /
• v.8 no.4
• /
• pp.203-209
• /
• 1998

The cutting oil emulsion microfiltration was carried out on dead-end call and crossflow systems equipped with 0.22 $\mu$m GVHP Millipore and 0.2 m stainless steel Mott microfiltration membranes, respectivdy. The oil drop size in the emulsion was varied from 0.07 to 0.22 $\mu$m. Cake filtration(CFM) and standard pore blocking models(SPBM) were applied to predict the permeation flux. The permeation fluxes of 0.01 vol% oil emulsion followed CFM for dead-end system very well under the condition of 400 rpm and below 100 kPa. The SPBM was, however, suitable for the permeation flux at 400 rpm and above 150 kPa. The oil layer on the membrane surface was destroyed and reproduced repeatedly as operating pressure was suddenly changed from 60 to 200 kPa, and then returned to 60 kPa. Also, we estimated the critical entry pressure(CEP) which is changed from CFM to SPBM, and CEP for dead-end system was around 100 kPa. The CEP increased from around 100 to 150 kPa for the crossflow system as the oil concentration increased from 0.01 to 0.03 vol% when Reynolds number was 7080.

• Journal of the Korean Ceramic Society
• /
• v.40 no.9
• /
• pp.867-873
• /
• 2003

$Si_{3}N_{4}$-BN based machinable ceramics were fabricated by hot-pressing at $1800^{\circ}C$ for 2 h under a pressure of 25 MPa. The microstructure, mechanical properties, and machinability were investigated. With increasing h-BN content from 5 vol% to 30 vol%, three point flexural strength decreased from 1000 MPa of monolithic S $i_3$ $N_4$ to 720～400 MPa. The fracture toughness, $K_{IC}$ , was decreased from 7.6 MPaㆍ$m^{1/2}$ of monolithic S $i_3$ $N_4$ to 6.5～4.1 MPaㆍ$m^{1/2}$. The grain size and aspect ratio of $\beta$-S $i_3$ $N_4$ slightly decreased with increasing h-BN content. S $i_3$ $N_4$ monolith could not be machined due to brittle fracture, but S $i_3$ $N_4$-BN based machinable ceramics could be machined without fracture, showing excellent machinability. With increasing h-BN content, the thurst force during cutting and micro-drilling process was decreased.

• The Journal of Korean Academy of Prosthodontics
• /
• v.30 no.3
• /
• pp.457-478
• /
• 1992

Electrical resistance strain gauges, brittle-coatings, Moir'e fringe analysis, photoelasticity methods, etc, have been employed in the study of stress analysis and three-dimensional photoelasticity method used in this experiment. The author fabricated a total of 24 samples of maxillary and mandibular edentulous ridges with normal and sharp shapes using epoxy resin, one of the photoelastic materials. In addition, complete denture made from artificial resin teeth in other twoo sizes, large and medium size, were affixed to the specimens and attached to an articulator. The following results were attained by cutting 9 slice specimens into 6mm thick portions, in accordance with the three dimensional photoelastic stress freezing method, to analyze stress distribution status under specific static loading in the central, lateral and protrusive occlusions of the shape of edentulous ridge. 1. In the case of central occlusion, when complete resin artificial teeth in large and medium sizes were used on normal and sharp alveolar ridges, high stress distribution was broadly shown in the labio-buccal sides, and low and concentrated in the lingual sides, in all cases. Generally, the highest stresses were shown at the top of the alveolus, or at 2mm below the top of the alveolus, particularly in the specimen 2, 3, and stresses were more or less the same in the symmetrical right and left sides. 2. In the case of lateral occlusion, when the same load was applied, high stresses were shown broadly at the working sides in both the labio-buccal and lingual sides, and low and concentrated at the balanced sides. The highest stresses were shown in the top of the alveolus on the working sides in specimen 2 portion, and the lowest stresses at the balanced sides in specimen 6, slightly higher stresses were shown at retromolar parts in the balanced sides. 3. In the case of protrusive occlusion, high stresses were broadly shown at the labio-buccal sides, and slightly higher stresses at the top 2, 4, and 6mm parts of the alveolus with concentration. The highest stresses were shown in specimen No. 5 and the lowes stresses in specimen 1, 9 and stresses were more of less the same at the symmetrical right and left sides.