• Title/Summary/Keyword: external materials

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Design of Tissue-Transfer Container Using Thermoelectric Element Module

  • Park, Yong Pil;Cheon, Min-Woo
    • Transactions on Electrical and Electronic Materials
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    • v.18 no.2
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    • pp.66-69
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    • 2017
  • The internal temperature of human-tissue transfers must be steadily maintained regardless of the external environmental changes. An ice pack and dry ice are the coolants for the transfer containers for which heat-insulating materials such as EPP (expended polypeopylene and EPS (expended polystrene) are used; however, changes of the external temperature/pressure and the melting of the coolants that is due to a long carriage result in changes of the internal temperature, and this makes it difficult to maintain the temperature. Accordingly, the thermoelectric element was used to design/manufacture a transfer container to maintain the internal temperature regardless of the external environmental changes. As a result of the measurement of the changes of the internal temperatures of the manufactured thermoelectric-element container and the EPS container over time, the internal temperature of the EPS container was increased, whereas the internal temperature of the thermoelectric-element container was maintained. The temperature of the distilled water that was poured into the containers indicated a pattern identical to that of the internal temperature.

Dialysis in double-pass cross-flow rectangular membrane modules with external recycle for improved performance

  • Yeh, Ho-Ming
    • Membrane and Water Treatment
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    • v.2 no.2
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    • pp.75-89
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    • 2011
  • The predicting equations for mass transfer rate in cross-flow rectangular dialyzers with double flow and recycle, have been derived by mass balances. The recycling operation has two conflicting effects. One is the desirable effect of the increase in fluid velocity, resulting in an increased mass transfer coefficient. The other is the undesirable effect of the reduction in concentration difference due to remixing, resulting in decreased mass-transfer driving force. In contrast a single-pass device without recycling, considerable improvement in mass transfer is achieved if the cross-flow rectangular dialyzer of same size is operated with double pass and external recycling. It is concluded that recycle can enhance mass transfer, especially for larger reflux ratio.

COERCIVE FIELD AND SPIN-GLASS BEHAVIOR OF AMORPHOUS Y-Fe ALLOYS

  • Fujita, A.;Fukamichi, K.
    • Journal of the Korean Magnetics Society
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    • v.5 no.5
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    • pp.762-766
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    • 1995
  • The coercive field $H_{c}$ of amorphous Y-Fe alloys in the spin-glass state has been investigated. Foramorphous $Y_{10}Fe_{90}$ alloy, the thermal variations of $H_{c}$ in the maximum external field $H_{max}=300,\;600$ and 1 k Oe exhibit a maximum. Since spin-glass behavior is strongly affected by external magnetic fields, the maximum point moves to lower temperature with increasing $H_{max}$. The appearance of the maximum in $H_{c}$ has been discussed in terms of the change of the spin-glass state in the external magnetic field. When the value of $H_{max}$ is 55 kOe, the temperature dependence of $H_{c}$ has no maximum and shows an exponential decrease with increasing temperature. Similar trends have been observed over a wide concentration range. The concentration dependence of $H_{c}$ is associated with the magnetic phase diagram.

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Flame Characteristics of Surface Part of Composite Emulsion Exterior Finishes (복합 에멀젼 외장마감재 표면부의 화염 특성)

  • Ryu, Hwa-Sung;Shin, Sang-Heon;Song, Sung-Yong;Kim, Deuck Mo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.11a
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    • pp.133-134
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    • 2019
  • As part of recent low-energy policies, thermal insulation standards for buildings are being tightened every year. The importance of external insulation methods is increasing due to the strengthening of insulation standards. Among the main materials used in the external insulation method, dry bit material is a finishing material composed of an organic binder and aggregate. When the fire occurs, the ignition of the surface part causes a direct fire on the thermal insulation material at the rear side when heat energy is concentrated. Therefore, it is important that the finishing material in dry insulation using a dry bit has a low fire spreading property in case of a fire and does not have a sustained combustion. The purpose of this study was to evaluate the fire spreadability by changing the internal fillers while using alkoxide-based acrylic emulsions, hybrid acrylic emulsions, and general acrylic emulsions in order to suppress the fire spreading properties of exterior finish materials.

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A Study on the Basic Properties of Exterior Insulation Plasterer Finishing Materials by Addition of Calcium Carbonate Powder (탄산칼슘계 분말 첨가에 따른 외단열 미장 마감재의 기초물성에 관한 연구)

  • Shin, Joung-Hyeon;Jo, Su-Yeon;Jung, Ui-In;Kim, Bong-Joo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.213-214
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    • 2021
  • External insulation method is used to conserve energy of buildings. However, the current external insulation method uses organic insulating materials to become a diffusion path in case of fire. In this study, the purpose of this study is to provide basic data on the required performance of the plastering material according to the CaCO3 powder addition of the finishing material of the external insulation method. In Figure 1, when powder was added, the adhesion strength decreased by 30% to 35% at 10% and 0% to 50% at 20% compared to Plain. In Figure 2, the moisture permeability increases approximately twice when powder is added. The results for the water absorption coefficient are shown in Figure 3.

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Production of Fine Tantalum Powder by Electronically Mediated Reaction (EMR) (도전체 매개반응(EMR)법에 의한 미세 Ta 분말 제조)

  • Park Il;Lee Chuel Ro;Lee Oh Yeon
    • Korean Journal of Materials Research
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    • v.14 no.10
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    • pp.719-724
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    • 2004
  • Production of fine tantalum powder by calciothermic reduction of tantalum oxides ($Ta_{2}O_5$) pellet through an electronically mediated reaction (EMR) has been investigated. $Ta_{2}O_5$ pellet feed and reductant calcium-nickel (Ca-Ni) alloy were charged into electronically isolated locations in a molten $CaCl_2$ bath. The current flow through an external path between the feed (cathode) and reductant (anode) locations was monitored. The current approximately 4.7A was measured during the reaction in the external circuit connecting cathode and anode location. Tantalum powder with approximately 99 $mass\%$ purity was readily obtained after each experiment. Tantalum powder by EMR using $Ta_{2}O_5$ pellet feed was fine compared with that of metal powder by metallothermic reduction and EMR using $Ta_{2}O_5$ powder feed.

The External Auricular Reconstruction with Inferior Based Retroauricular Flap Including the Posterior Auricular Artery

  • Choi, Jong Hwan;Ki, Sae Hwi
    • Archives of Reconstructive Microsurgery
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    • v.25 no.1
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    • pp.1-6
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    • 2016
  • Purpose: The external ear is a common area of trauma on the body prone to exposure of ultraviolet light, which can lead to skin cancer. Thus, variable techniques have been developed and used for reconstruction of the external ear. The aim of this study is to review the surgical method, its area of application, as well as advantages and pitfalls of reconstruction of the external ear with inferior based retroauricular flaps. Materials and Methods: Eight patients underwent external ear reconstruction with inferior based retroauricular flap for external ear defects in our institute from September 2012 to June 2015. According to the area of the defect, patients were classified as middle 1/3 (n=4), inferior 1/3 (n=2), superior auroculo-cephalic sulcus (n=1), and external auditory canal (n=1). Results: All of the flaps survived the operation and there was no marginal necrosis. Mean size of the defect was $2.8{\times}1.8cm$ and mean size of the retroauricular flap was $5{\times}2cm$. For insetting of the flap, a subcutaneous tunneling technique was used in 6 cases and rotation without subcutaneous tunneling was used in 2 cases. Transient paresthesia occurred in 3 cases. Two cases recovered within 3 months but one case did not recover until 6 months. Conclusion: The inferior based retroauricular flap is an available technique in external ear reconstruction with one stage operation.

Analysis of the Types of External Wall and Roof Structure Layer Composition of CLT Building (CLT 건축물의 외벽 및 지붕 구조체 레이어 구성 유형 분석)

  • Yoo, Dong-Wan;Lee, Tae-Goo
    • Journal of the Korean Institute of Rural Architecture
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    • v.22 no.4
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    • pp.71-78
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    • 2020
  • Today, the whole world is going through a big chaos due to the COVID-19, but paradoxically, the emergence of COVID-19 has been leading to the need for sustainable development, such as Green New Deal that can improve global warming and carbon emissions, and the need for sustainable architecture is growing bigger and bigger in the architectural field as well. The level of CLT buildings in Korea is at a very rudimentary stage, while CLT buildings remedying existing wooden buildings are getting the spotlight among European countries for sustainable architecture. This study was conducted to categorize structure layer compositions of overseas CLT buildings and analyze architectural techniques and materials applied by collecting and analyzing information about CLT structure layer compositions of overseas CLT building-related institutions, companies and cases. When classifying structure layer compositions of foreign CLT buildings depending on the roles of layers. it was revealed that exterior wall structure layers were combined and organized within a sequence of external finishing, ventilation, waterproof, board, external insulation, airtightness, structure, airtightness, interior insulation, interior finishing, sloped roof structure layers were external finishing, ventilation, waterproof, board, external insulation, airtightness, structure, airtightness, interior insulation, interior finishing, flat roof structure layers were external finishing, ventilation, waterproof, planking wood, external insulation, waterproof, external insulation, airtightness, structure, airtightness, interior insulation, interior finishing.

Passive Damping Enhancement of Composite Beam Using Piezo Ceramic Connected to External Electrical Networks (외부 회로가 연결된 압전 세라믹을 이용한 복합재 보의 수동 감쇠 개선)

  • Yang, Seung-Man;Kim, Do-Hyung;Han, Jae-Hung;Lee, In
    • Composites Research
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    • v.12 no.2
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    • pp.1-9
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    • 1999
  • The piezoelectric material connected to external electric networks possesses frequency dependent stiffness and loss factor which are also affected by the shunting circuit. The external electric networks are generally specialized for two shunting circuits: one is the case of a resistor alone and the other is the combination of a resistor and an inductor. For resistive shunting, the material properties exhibit frequency dependency similar to viscoelastic materials, but are much stiffer and more independent of temperature. Shunting with a resistor and inductor introduces an electrical resonance, which can change the characteristics of structural resonance optimally in a manner analogous to a PMD (proof mass damper). Passive damping enhancement of composite beam using piezoelectric material connected to external electrical networks is achieved and presented in this paper.

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