• Transactions on Electrical and Electronic Materials
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• 제13권1호
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• pp.39-42
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• 2012

To study the physical and chemical properties, solid solutions of $(Sr_{1-x}Ba_x)NdFe{^{3+}}_{1-\tau}Fe{^{4+}}_{\tau}O_{4-y}$ system with x=0.0(SBN-0), 0.1(SBN-1), 0.2(SBN-2) and 0.3(SBN-3) were synthesized in air at 1,473 K and annealed in air at 1,073 K for 24 h. X-ray powder diffraction assured that the four samples had tetragonal symmetries (I4/mmm). Their lattice volumes increased gradually with x values. Nonstoichiometric chemical formulas were formulated using the data such as $\tau$(amount of $Fe^{4+}$ ion) and y(oxygen deficiency) values using Mohr salt analysis. It was found out that all the four samples had excessive oxygen (4-y>4.0). All the samples started to lose some of their oxygen at around 613K(TG/DTA thermal analysis). They exhibited semiconductivities in the temperature range of around 283-1173K. All the four specimens had sufficient tensile strength to endure the force of 19.6 N (2 kg of weights) and the conductivity values of the ECIAs which were painted on pieces of glass with the area of $150mm^2$ ($10mm{\times}15mm$) and it was in the order of ECIA-0${\rightarrow}$ECIA-1${\rightarrow}$ECIA-2${\rightarrow}$ECIA-3 at a constant temperature.

• Geomechanics and Engineering
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• 제38권2호
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• pp.125-137
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• 2024

In paste backfill mining, cemented coal gangue-fly ash backfill (CGFB) can effectively utilize coal-based solid waste, such as gangue, to control surface subsidence. However, given the pressurized water accumulation environment in goafs, CGFB is subject to coupling effects from water pressure and chloride ions. Therefore, studying the influence of pressurized water on the chlorine salt erosion of CGFB to ensure green mining safety is important. In this study, CGFB samples were soaked in a chloride salt solution at different pressures (0, 0.5, 1.5, and 3.0 MPa) to investigate the chloride ion transport characteristics, hydration products, micromorphology, pore characteristics, and mechanical properties of CGFB. Water pressure was found to promote chloride ion transfer to the CGFB interior and the material hydration reaction; enhance the internal CGFB pore structure, penetration depth, and chloride ion content; and fill the pores between the material to reduce its porosity. Furthermore, the CGFB peak uniaxial compression strain gradually decreased with increasing soaking pressure, whereas the uniaxial compressive strength first increased and then decreased. The resulting effects on the stability of the CGFB solid-phase hydration products can change the overall CGFB mechanical properties. These findings are significant for further improving the adaptability of CGFB for coal mine engineering.

• 한국광물학회지
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• 제26권1호
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• pp.9-18
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• 2013

저항성 황화광물 정광으로부터 최적의 gold를 용출시키기 위하여 염소-차아염소산 용액과 다양한 온도와 농도를 소금소성정광에 적용하였다. 정광은 황철석, 황동석, 방연석으로 구성되었으며, 공기 중에서 $750^{\circ}C$ 소성처리하자 적철석으로 변환되었고, 소금으로 소성처리하자 적철석과 난토카이트(nantokite, CuCl)으로 변환되었다. 다양한 변수로 용출실험을 수행한 결과, 염소-차아염소산 나트륨 혼합 비율 1 : 2에서, $FeCl_3$ 첨가량 1.0 M에서, 광액농도 1.0%에서, 그리고 용출온도 $60^{\circ}C$에서 최대의 금 용출율을 얻었다. 금 용출율은 정광에서보다 소성정광에서 더 높게 용출되었고, 소성정광에서보다 소금소성정광에서 더 높게 용출되었다. XRD 분석 결과, 소금소성정광에서, 그리고 $60^{\circ}C$의 염소-차아염소산 용출용액 고체 잔유물에서 석영이 관찰되었다.

• 자원리싸이클링
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• 제27권5호
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• pp.61-68
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• 2018

알루미늄 드로스는 알루미늄 용해 공정에서 용탕 표면에 발생하는 산화물 덩어리로서, Salt 유무에 따라 화이트드로스와 블랙드로스로 구분된다. 화이트드로스의 경우 금속 함량이 높아 용해 공정으로 재활용 되지만, 블랙드로스는 금속 함량이 낮고 성분 분리가 어려워 대부분 매립 처리되며, 물과 반응하면 가스와 발열 반응이 일어나 토양오염의 원인으로 작용한다. 하지만 블랙드로스에는 NaCl과 KCl과 같은 Salt 성분과, $Al_2O_3$, MgO와 같은 무기소재가 포함되어 있어 이러한 유가자원을 회수하고 소재화하는 기술 연구가 필요하다. 본 연구에서는 알루미늄 블랙드로스를 재활용하기 위한 공정을 제시하였다. 파쇄-용해(Dissolution)-고액분리-감압증발을 거치는 공정을 통하여 블랙드로스에 존재하는 무기물과 용해성 물질을 분리하였다. 물과 블랙드로스 함량을 제어하여 조건에 따라 분리물의 회수율을 최적화하였으며, 블랙드로스:물 비율이 1:9 일 때 91 wt.%의 Salt flux 회수율을 보임을 확인하였다. 추가적으로, 회수된 무기물을 이용한 제올라이트의 합성을 통하여 블랙드로스의 소재화 가능성을 확인하였다.

• 자원리싸이클링
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• 제10권5호
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• pp.36-43
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• 2001

The chlorine component in fly ash from municipal solid waste incineration ash was removed by water washing for the purpose of recycling fly ash as a raw material of ordinary portland cement. The samples were a different kind of 리y ashes using $Ca(OH)_2$and NaOH as media of wet scrubber for flue gas cleaning. The content of soluble salts of fly ash using $Ca(OH)_2$and NaOH was 32.8%, 50.1% and the content of chlorine component, 22.9% and 26.0% respectively, which was KCl, NaCl, CaC1OH mainly. When each fly ash was washed using water under conditions of a agitation speed of 300 rpm, a liquid to solid ratio of 10, most soluble salts in fly ash were dissolved within 30 minutes and the content of chlorine component in ash was diminished to the content of 4.4%, 2.O% at $20^{\circ}C$ and 1.7%, 0.8% at $50^{\circ}C$ respectively. And the main compound of residual chlorine component in ash after water washing was friedel`s salt ($3CaO.A1_2$$O_3$.$CaCl_2$.$10H2$O). From analysis results of water quality for wastewater by water washing, the components exceeding discharged wastewater standard were only Pb and Cd. But As pH was controlled to 10 with addition of $CO_2$(g) or $Na_2$$_CO3$in water, the concentration of heavy metals such as Pb and Cd was also under discharged wastewater standard.

• 폴리머
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• 제32권2호
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• pp.189-192
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• 2008

Styrylpyrylium salt 화합물(DHSP)을 합성하고 광이량화시켜 cyclobutane형 이량체(DHSP dimer)를 합성하였다. 여기에 메타크릴레이트기를 도입하여 DMSP dimer를 합성하였다. DMSP dimer 광가교물의 FT-IR 분석 결과, 크랙 생성에 의해 cyclobutane환이 개열되어 styryl C=C 구조로 되돌아가는 것으로 판단되었다. 385 nm의 빛에 의하여 DHSP는 626 nm의 형광을 방출하는 반면 DHSP dimer는 매우 약한 형광만을 나타내었다. DMSP dimer의 광가교 필름에 microcrack을 생성시키고 $330{\sim}385\;nm$의 빛을 조사한 결과, 크랙 부분에서의 형광 방출이 확인되었다.

• E2M - 전기 전자와 첨단 소재
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• 제9권2호
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• pp.146-151
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• 1996

PZT powders were prepared by the molten salt synthesis method. The porous PZT ceramics were made from a mixture of PZT and polyvinylalcohol(PVA) by BURPS(Bumout Plastic Sphere) technique. The 3-3 type composites were fabricated by impregnating an sintered porous PZT ceramics with various polymer matrices. The relative permittivity of 3-3 type composite specimens was shown 860-1,100 smaller than that of solid PZT ceramics(2,100), and the dissipation factors of composite specimens were about 0.02 to 0.03. The piezoelectric coefficient d$_{33}$ of composite specimens(285-328*10$^{12}$ C/N) was comparable with that of single phase PZT specimens(364*10$^{-12}$ C/N). The thickness mode coupling factor k$_{t}$(O.5-0.6) of composite specimens was comparable with that of single phase PZT specimens(k$_{t}$-0.7), and the mechanical quality factor of composite specimens was smaller than 10, and thus these 3-3 type composite specimens would be believed as a good candidates for broad band transducer applications.ons.

• 한국식생활문화학회지
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• 제27권6호
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• pp.702-709
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• 2012

Seolleongtang, a traditional broth in Korea, is expected to become a hot global item for its unique flavor and healthiness. In this study, the correlations between sensory attributes and physicochemical characteristics were studied for the popular seolleongtang stock products through descriptive analysis, sensory evaluation and analysis of salt, soluble solid, protein, viscosity and color for the quality control. Our results indicate that color, concentration, viscosity, and freshness are important attributes in evaluating the quality of seolleongtang stock. There were significant differences between preference and sensory attributes among the stock products. Significant correlations were found between flavor and texture and overall acceptability, as well as beany odor and aroma. Preference and physicochemical aspects also correlated, and indicate that a range of salt, solubility, and viscosity are applicable as quality control factors in seollengtang stock.

• 한국잡초학회지
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• 제17권2호
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• pp.135-138
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• 1997

Sulfonylureas are highly active herbicides which can be applied at very low rate(10-50g/ha) to control broadleaf weeds. The nature of this category of compound is, however, very unstable toward hydrolysis. Therefore, the preparation of these compounds as liquid formulation was not possible. Most of the current formulations of sulfonylurea are in dry forms such as water dispersible granule or wettable powder. Even in these dry forms, the active ingredients also encounter significant chemical decomposition. This study involves the preparation of the sulfonylurea salts by reacting the parent compound with base such as sodium hydroxide. The salt becomes stable toward hydrolysis and it turns soluble when diluted with water. This discovery makes the preparation for liquid formulation or soluble granule of sulfonylurea possible. The stoichiometry of base added to the neutral sulfonylurea is controlled quite precisely. The base has to be added enough to quench the acidic impurities in the technical material and to convert the active ingredient into salt. However, the base should not be overused to cause further saponification of the sulfonylurea salts. The chemical nature of these compounds is presented and the chemical reaction is described. New soluble liquid formulation and solid granule formulation of sulfonylurea are suggested.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2633-2636
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• 2011

A new type of ionic liquid based on N-(3-aminepropyl)imidazolium iodide, called IIQAI, which consists of imidazolium and quaternary ammonium salt, and APII-(hydroxyethyl, propyl, hexyl) were synthesized and used as ionic liquid in dye-sensitized solar cells. APII-hexyl is solid, whereas IIQAI, APII-(hydroxyethyl, propyl) are viscous liquids. The synthesized ionic liquid showed relative thermal stability compared to the commercial ionic liquid of DMII. Among them, IIQAI was more stable than the other ionic liquid because of the two salt groups. APII-hydroxyethyl, which contains two hydroxyl groups, showed low viscosity with good flow. New types of ionic liquids were examined by $^1H$-NMR spectroscopy, thermo gravimetric analysis (TGA). IIQAI enabled a solar energy conversion efficiency of 6.3%, which is slightly higher than that of the referenced (DMII, 6.2%).