• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.13-17
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• 2005

Children and teenagers have a higher frequency of proximal surface caries in the posterior teeth than adults. For proximal restoration, class II amalgam or stainless steel crown has been widely used in the past, however composite resin restoration is getting ore popular due to it's superior cosmetic appearance. When applying composite resin on proximal area, various types of matrix bands can be utilized according to the operator's reference or skill. Such bands have several clinical effects including suitability for proximal margin, reduction of micro-leakage, moisture-control against saliva and ease finishing and polishing. In this case report, orthodontic bands were utilized instead of matrix bands as a remedy for proximal restorations in both primary and permanent teeth and their clinical advantages are as follows. 1. Orthodontic bands showed superior marginal adaptation compared to conventional matrix bands and moisture-control against saliva was excellent. 2. While applying composite resin, deformation of restoration material was estimated to be insignificant due to he rigidity of the orthodontic bands. 3. Natural tooth contour of the orthodontic bands facilitates to reproduce proximal tooth contour of the restoration. 4. In general, pediatric dentists are accustomed to applying orthodontic bands and this may allow pediatric dentists to make proximal composite restorations more efficiently than other dental specialists.

• Journal of the Korean Wood Science and Technology
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• v.40 no.1
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• pp.10-18
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• 2012

A high airtightness is required for the residential spaces constructed recently to save cooling and heating energy through improving insulation performance. Because the chances to release steam formed by human activity in building and inflow of water vapor in outdoor air to residential space are reduced, the natural humidity control performance of interior materials has become more important. In this study, hygroscopic performance of thermo-physically treated wood (Pinus koraiensis) was estimated. At various relative humidity condition, the water vapor adsorption and desorption rates of wooden materials were measured as well as equilibrium moisture content. Effects of roughness and surface microstructure as physical factors and functional groups as chemical factors on the hygroscopicity were analyzed. It is expected that the results from this study and further study of measuring moisture generation in residential spaces could contribute to install a system for evaluating the hygrothermal performance of wooden building.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.1
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• pp.59-70
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• 1998

A steady-state molecular diffusion experiment was conducted to evaluate the water vapor proof properties of paper Handsheets prepared from unbleached Itraft pulps(UKP) and old newspapers(ONP) and four different types of polymer-laminated white duplex board were tested under appropriate standard conditions. The diffusivity was determined on the basis of the Fickean first law. Results obtained from this study can be summarized as follows ; 1. The diffusivity data for handsheets showed about $10^{-5}cm^2/min$. whereas polymer-laminated paperboards had remarkably improved water-vapor resistance with about $10^3 to 10^4$ times lower diffusivity : 2. Sheet basis weight, wet-swelling and sizing degree had little influence on the diffusivity of paper; 3 Linear relationship existed between sheet density and diffusivity, and, 4. Highly sfgnificant linear relationship could be observed between diffusivity and Darcy s gas permeability. Results indicate that diffusivity, an intrinsic property of paper, can provide a valuable information for precise evaluation and improved quality control of water-vapor proof properties of paper.

• Journal of the Korean Society of Tobacco Science
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• v.26 no.1
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• pp.43-49
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• 2004

This study was carried out to investigate moisture sorption and desorption characteristics followed by tobacco type. Experiments were performed at various temperature(5, 15, 25, 40 $^{\circ}C$) and relative humidity range (11～84 %) controlled by saturated salt solution. Regression equation was obtained to predict equilibrium moisture according to various relative humidity, temperature and tobacco types. The obtained regression equation showed high $R^2$(above 0.95) and predicted accurate equilibrium moisture. Equilibrium moisture contents declines in the following order when a relative humidity is 50 % or above: expanded stem, flue-cured, expanded tobacco, reconstituted tobacco, USA flue-cured, orient, burley. To maintain 13 % moisture of each tobacco type in the range of 5～40 $^{\circ}C$ it is recommendable to control relative humidity 49～56 % for expanded stem, 50～57 % for flue-cured, 54～61 % for USA flue-cured, 56～60 % for reconstituted tobacco, 57～62 % for expanded tobacco, 58～64 % for orient and 58～65 % for burley, respectively. It means that the relative humidity of each tobacco type should be differently controlled to maintain the same moisture under the same temperature. In the range of 5～25 $^{\circ}C$, the lower temperature showed the higher equilibrium moisture content.

• Journal of the Korean Wood Science and Technology
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• v.19 no.4
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• pp.52-61
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• 1991

In this paper, the difference of the property of absorption and desorption for five species in semi-steady state are studied. The species used are listed in Table 1 and the dimension of specimen was $8\times8{\times}T$(Tangential direction)cm and tested in various conditions. A change of average moisture content with time were measured in each cycles. The results obtained are summarized as follows. When the relative humidity in air was maximum or minimum, the distribution of moisture In wood of all specimens were illustrated by exponential curves of decrease or increased from lace 10 center of wood. From the consideration of coefficient of decrease(C), the amount of moisture change of spruce was larger than the others. The pheonomenon was considered no relation to the specific gravity in air dry, but the wood structures. The velocity of the absorption and desorption for species decreased in the order spruce(Picea sitchensis) neodobam(Fagus crenata), solsong(Tsuga heterophylla), meranti(Shorea sp.) and kaesoo(Cercidiphyllum japoicum). In case of constant temperature and water vapor pressure is changed. the amount of absorbed moisture was larger than that of constant water vapor pressure and temperature vaned. In this fact, it is considered that the property of sorption of wood is strongly influenced by vapor pressure gradient than temperature gradient.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.2
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• pp.26-32
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• 2003

For the purpose of manufacturing water-resistant corrugated board boxes for agricultural products in the cold chain system, the effects of fiber types, wet strength agents and a moisture-proof chemical on the properties of the base papers were investigated first. PAE(polyamide amine epichlorohydrin) showed better performance than MF(melamine formalde-hyde) over broad stock pH ranges, which was prefered as wet strength agent for the paper grade. When short fibers(AOCC, KOCC) were mixed with long fiber(UKP) in certain ratios, some physical properties of the paper made with mixed fibers were similar to those of the paper made with UKP only. Paper containing AOCC showed the biggest increase in water resistance when PAE was added to the stock. Synergistic effects in moisture-proof and some mechanical properties of paper were appeared when PAR was added internally, together with the coating of a moisture proof chemical on the sheets.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.3
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• pp.43-52
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• 2018

This study is conducted to evaluate the performance of ceramic panels and painting materials for humidity control which are developed in non-plastic room temperature hardening structure as part of a project to improve a residential environment for the low-income class, rather than the performance of high-priced humidity control materials that are produced with the existing plasticity processing. The testing methods included the measurements of absorption & desoprtion of humidity per material; Mock-up Testing; an evaluation method of comparing the absorption & desoprtion performances of Ecocarat, ceramic panels and painting materials through Living Lab. According to the measurements of absorption & desoprtion per material, ceramic panels, E panel, and ceramic painting material showed 73.3g/m2, 96.6g/m2, and 111.1g/m2, respectively. That is, the performance of humidity control of each material was found to be good in the order of: Ceramic Paint > E panel > Ceramic Panel. According to performance evaluation testing with Mock-up test and Living Lab, Ceramic Paint, Ecocarat, and Ceramic Panels showed better absorption & desoprtion performances in the order.

• KIEAE Journal
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• v.12 no.5
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• pp.71-76
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• 2012

As reviewed of developments of Korean earth architecture, earth-made buildings have been dwindled gradually since "the new community movement" and earth have been recognized as materials which are not so good to human health and in result, earth-related techniques have been also forgotten. However, recently the earth architecture has been more attracting back many attentions thanks to the people who are interested in health and wellbeing and the earth related techniques or skills got keenly required. The present study has investigated and reproduced earth finishing materials which are based on natural materials as basic stuffs to use them as the finishing materials of the modern earth architecture. For the test, the finishing materials have been divided roughly into sorts of pastes and oils. In case of applying finishing materials onto earth surfaces, the moisture permeability test was conducted to measure a water-absorbing speed, and at the case of using finishing materials for interior works moisture adsorption/desorption test was performed to verify the indoor humidity regulation ability, and further a test to check whether to be stained when contacted with the finishing materials, was conducted. If there is not any stain it might be recognized to be high quality of moisture adsorption/desorption and so seaweed pastes or starches might be used for paste finishing materials and for natural oils, beans are desirable in practical ways. As low-quantity of moisture adsorption materials, linseed oil is most desirable and also beaned water over75% are thought to be useful.

• Journal of the Korean Society for Nondestructive Testing
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• v.15 no.4
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• pp.540-548
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• 1996

In general residual stress is measured by X-ray diffraction method but in case of bonding residual thermal stress it is inadequate technique to examine the stress singularity. Therefore Two-dimensional elastic boundary element analyses were carried out to investigate the residual thermal stress and stress singularity of bonding interface in Al/Epoxy. This boundary element results were compared with the strain gauge measurements. The effects of different interface models, sub-element and adherend thickness are presented and discussed. On the basis of the obtained results, interface delamination causing by normal stress is expected and stress singularity is observed more intensively increasing with adherend thickness. It is concluded that the bonding strength of Al/Epoxy interface can be estimated correctly by taking into account the stress singularity at the edge of the interface.

• Korean Journal of Food Science and Technology
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• v.19 no.2
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• pp.176-180
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• 1987

The sorption characteristics of dried garlic flakes stored at various relative humidity and storage temperature were studied. At low relative humidity below RH 51%, the sorption equilibrium was easily attained, whereas at higher relative humidity above RH 67%, the flakes were browned by higher equilibrium moisture content. The flakes were browned at relative humidity above 67% at $20^{\circ}C$ and $35^{\circ}C$, above 84% at $5^{\circ}C$, respectively. The moisture contents of monolayer value for the flakes were ranging from 5.80% to 6.20% (DB) with varying temperatures. And the necessity of moisture-proof packaging material suggested for the long term storage of the flakes because the lower moisture content and storage temperature, the higher driving force of wetting. Regression equation for browning rate prediction with relative humidity and storage temperature of the flakes was determined.