• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.1
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• pp.57-65
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• 2005

This study suggested a new method for the solidification of molten salt waste generated from the electro-metallurgical process in the spent fuel treatment. Using binary material system, sodium silicate and phosphoric acid, metal chlorides were converted into metal phosphate in the micro-reaction module formed by SiO$_{2} particles. The volatile element in the reaction module would little vaporized below 1100$^{circ}$C After the gel product was mixed with borosilicate glass powder and thermally treated at 1000$^{circ}$C, li exists as Li$_{3}$PO$_4$ separated from glass phase and, Cs and Sr would be incorporated into an amorphous phase from XRD analysis. In case of the addition of ZrCl$_{4}$ to the binary system, the gel products were transformed into NZP structure considered as an prospective ceramic waste form after heat-treatment above 700 $^{circ}$C. From these results, the gel-route pretreatment can be considered as an effective approach to the solidincation of molten salt waste by the confirmed process or waste form and this also would be an alternative method on the ANL method using zeolites in USA by the confirmation of its chemical durability as an future work.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.11
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• pp.781-784
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• 2013

Ocean dumping of sewage sludge is banned. Therefore, it is needed to develop alternative treatment method. Sewage sludge and waste glass are used to prepare lightweight brick. Large amount of energy is consumed to prepare building material, because of its high preparation temperature, or above $1,200^{\circ}C$. We study to prepare lightweight brick, using sewage sludge and waste glass as raw materials in this research. Lightweight brick was made at low temperature of below $800^{\circ}C$ to reduce $CO_2$ emission by geopolymer technique. Calcination temperature, mixing ratio of sewage sludge/waste glass and water glass/water were discussed to evaluate their effect on the brick prepared. In this study, the optimal conditions for preparing bricks was $750^{\circ}C$ of firing temperature, 1.5 of mixing ratio for water glass/water and 10 : 90 wt% of sewage sludge/waste glass. At this condition, compressive strength and specific gravity of brick prepared were 5.1 MPa and 0.46, respectively. These values satisfy the criteria on a lightweight brick.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.3
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• pp.37-43
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• 1999

Co-firing incompatibility between the low temperature sinterable Glass/ceramic and Ag-thick film was studied. The dielectric material, which has been developed for microwave frequency applications, consists of $SiO_2-TiO_2-Bi_2O_3$-$Bi_2O_3$-RO system(RO:BaO -CaO-SrO) crystallizable glass and $Al_2O_3$as a ceramic filler. The large camber in the sintered specimen and cracks at the Ag-film under the influence of the camber occurred due to the difference of densification rate between the ceramic sheet and the Ag-film $B_2O_3$addition to the Glass/ceramic mixture reduced the severe camber. The cambers decreased with increasing the $B_2O_3$ content, and completely disappeared with 14 vol% $B_2O_3$addition. With additions of $B_2O_3$, $\varepsilon_{r}$ decreased abruptly, Q$\times$f value increased largely and the $\tau_f$ value of the material quickly shifted to positive one.

• Journal of Technologic Dentistry
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• v.30 no.2
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• pp.39-45
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• 2008

Titanium and its alloys are widely used as dental implants materials because of their excellent mechanical properties. However, the alumina and zirconia ceramics are preferred to use as the substitute of Ti implants because there is a problems in esthetics and biocompatibility in Ti implant. The the glass infiltrated alumina ceramics are studied to increase the toughness and biocompatibility. The 45S5 and soda-lime glass powder was mixed with ethanol at ratio of 1:1 and brushed on the surface of alumina. Then it was heat treated in the electric furnace at $1400^{\circ}C$ from 30 min. to 5 hours. The glass powder was controlled from 200 to $350{\mu}m$ using ball milling. After heat treatment, the glass infiltrated specimen was tested in universal testing machine to measure the bending strength. The surface microstructure of each specimen was observed with SEM. The biocompatibility of 45S5 and soda-lime glass coated alumina was investigated using PBS at $36.5^{\circ}C$ incubator. The specimen was immersed in PBS for 3, 5, 7, 10 days. After that, the surface morphology was investigated with SEM. As the results of experiment, the 45S5 bioglass infiltrated alumina show the increase of bending strength according to the increasing of heat treatment time from 30 min. to 5 hours at $1400^{\circ}C$ Finally the 1370N bending strength of alumina increased to 1958N at 5 hours heat treatment, which shows 1.4 times higher. In contrast to this, the soda lime glass infiltrated alumina ceramics shows the convex curve according to heat treatment time. Thus it shows maximum bending strength of 1820N at 1 hour heat treatment of $1400^{\circ}C$ It gives 1.3 times higher. However, the bending strength of soda lime glass infiltrated alumina is decreasing with increasing heat treatment time after 1 hour. The precipitation on the surface of 45S5 glass infiltrated alumina was revealed as a sodium phosphate ($Na_{6}P_{6}O_{24}6H_{2}O$) and the amount of precipitation is increasing with increasing of immersion time in PBS. In contrast to this, there is no precipitation are observed on the surface of soda lime glass infiltrated alumina. This implies that 45S5 glass infiltrated alumina brings more biocompatible when it is implanted in human body.

• Resources Recycling
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• v.31 no.4
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• pp.49-55
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• 2022

In this study, the heavy metal ions (of Pb, Cd, Cr, and Hg) in wastewater were removed using a spent Li₂O-Al₂O₃-SiO₂-based crystallized glass previously used as an induction top plate material. Changes in the removal efficiency of heavy metals according to different reaction parameters, such as the amount of zeolite used as a heavy-metal adsorbent, adsorption time, initial concentration of the heavy metals, and pH of the initial solution, were investigated. As the amount of zeolite added increased, the heavy-metal removal efficiency also increased. Adsorption time had a considerable influence on adsorption characteristics, and the removal efficiency of all heavy metals increased with increasing adsorption time. In the case of Cd, the removal efficiency was greatly improved depending on the adsorption time. The initial concentration of the heavy-metal solution did not affect the removal efficiency; however, the initial pH of the heavy-metal solution affected the removal efficiency. More specifically, the removal efficiency of Cd increased while that of Pb and Cr decreased with increasing pH. The adsorption characteristics of Hg were not significantly affected by pH.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.1
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• pp.19-24
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• 2007

The effects of $B_2O_3-SiO_2-R(R;CaO,\;BaO,\;ZnO,\;Bi_2O_3)$ borosilicate glass system on the sintering behavior and microwave dielectric properties of ceramic/glass composites were investigated as functions of modifier, glass addition ($30{\sim}50\;vol%$) and sintering temperature ($500{\sim}900^{\circ}C$ for 2 hrs). The addition of 50 and 45 vol% glass ensured successful sintering below $900^{\circ}C$. Sintering characteristics of the composites were well described in terms of modifier. Borosilicate glass enhanced the reaction with $Al_{2}O_{3}$ to form pores, second phases and liquid phases, which was responsible to component of modifier. Dielectric constant (${\varepsilon}_{r},\;Q{\times}f_{o}$) and temperature coefficient of resonant frequency (${\tau}_{f}$) of the composite with 50 and 45 vol% glass contents($B_{2}O_{3}:SiO_{2}:R=25:10:65$) demonstrated A-CaBS(7.8, 2,560 GHz, -81ppm/$^{\circ}C$), A-BaBs(5.8, 3.130 GHz, -64 ppm/$^{\circ}C$), A-ZnBS(5.7, 17,800 GHz, -21 ppm/$^{\circ}C$), A-BiBs(45 vol% glass in total)(8.3, 2,700 GHz, -45 ppm/$^{\circ}C$) which is applicable to substrate requiring an low dielectric properties.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.214-214
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• 2003

고체 고분자 전해질에 대한 연구는 1979년 wright와 Armand에 처음 시작된 이래로 지난 20여년간 연구가 계속적으로 지속되고 있다. 전지의 적용되기 위해 전해질이 갖추어야 할 조건중에 이온전도도가 상온에서 10-4 S/cm 이상의 전도도를 나타내야 하지만 지금까지 연구되고 있는 여러 고체 고분자 전해질은 이런 조건을 만족시키지 못하고 있는 실정이다. 본 연구에서는 이런 상온에서의 이온 전도성을 향상시키기 위해 여러 종류의 실리카와 세라믹 계열의 첨가제를 첨가하여 이온전도성의 향상을 꾀하고자 하였다. 본 연구에서는 고체 고분자 전해질의 host polymer로써 분자량 400,000 의 Polyethylene oxide를 사용하였으며 Lithuim salt로는 Lithium (bisperfluroethylsulfonyl)imide(3M)를 기본적으로 사용하였다. 여기에 가소제의 역활로써 (3-cyanopropyl)methylsiloxane cyclics를 첨가하였고 표면그룹이 CH3와 OH기로 이루어진 기능성 나노 실리카를(<11nm)이용하여 함량별 전기 화학적 특성 및 기본 물성을 측정하였다. 기본적으로 이 네 가지 물질을 유기용매 Acetonitril에 잘 용해하여 Solid Casting방법으로 80-100 마이크로의 복합고분자 전해질을 제조하였다. Homogeneous하고 uniform한 필름 제조하기 위해 9$0^{\circ}C$에서 열처리를 24h 동안 실시하였다. 제조되어진 복합고분자전해질은 XRD를 통하여 결정성을 조사하였고 DSC를 이용하여 유리 전이온도 및 결정화도를 조사하였다. 복합고체고분자의 전기화학적 성질을 평가하기 위해 blocking electrode를 제작하여 임피던스 스펙트로 스코피를 이용하여 이온전도성을 측정하였다. 또한 복합 고분자 전해질의 온도의존성에 대해서도 조사하였다. 또한 실제 전지의 작동구간에서의 전해질의 안정성을 확인하기 위해 LSV를 측정하였고. Li metal을 사용하여 non-blocking electrode를 제작하여 복합고분자 전해질과의 계면저항을 측정하였다.

• Journal of the Korean Vacuum Society
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• v.21 no.3
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• pp.158-163
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• 2012

In this work, we have fabricated the $TiO_2$ thin films on Si and glass, polymer insulator substrates as the self-cleaning coating of polymer insulator. $TiO_2$ films were deposited by RF magnetron sputtering method with $TiO_2$ ceramic target and $TiO_2$ films of 100 nm thickness were fabricated with various RF powers. We have investigated the optical and surface, and structural properties of $TiO_2$ films prepared with various RF powers. As a result, the value of the contact angle of $TiO_2$ thin film is increased with increasing RF power and the value of the rms surface roughness is increased. The transmittance is decreased with increasing RF power. These results indicate that the variation of the surface and optical properties of $TiO_2$ thin films is related to the sputtering effects by increasing RF power.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.1
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• pp.191-196
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• 2010

Aluminum doped zinc oxide (AZO) films have been prepared on Coming 7059 glass substrates by r.f. magnetron sputtering method. A powder target instead of a conventional sintered ceramic target was used in order to improve the utilization efficiency of the target and reduce the cost of the film deposition process. The influence of sputter pressure on the structural, electrical, and optical properties of AZO films were studied. The AZO films had hexagonal wurtzite structure with a preferred c-axis orientation, regardless of sputter pressure and target types. The crystallinity and degree of orientation was increased by increasing the sputter pressure. For higher sputtering pressures, a reduction of the resistivity was observed due to a increase on the mobility and the carrier concentration. The lowest resistivity of $6.5{\times}10^{-3}\;{\Omega}-cm$ and the average transmittance of 80% can be obtained for films deposited at 15 mTorr.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.1
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• pp.13-18
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• 2000

Low temperature co-fired ceramics on metal (LTCC-M) is efficient for embedding passive components with good tolerance in a module due to the dimensional stability in x and y directions by the constraint of metal core during the firing. In addition, the radiation noise can be reduced by metal core. In this paper, embedded passive components were introduced and a power amplifier module (PAM) fabricated by using the passive components was explained. The embedded passive components in test patters showed the tolerance of 10~20% and the good repeatability in tolerance of embedded passives was maintained in module fabrication. The shortened traces in multi chip modules (MCMs) make the signal delay time decreased and the embedded passives simplify the packaging processes owing to the less solder points, which enhance the electrical performance and increase the reliability of the modules. The LTCC-M technology is one of the promising candidates for RF application and is expected to expand its applications to power and high performance devices.