• 한국세라믹학회지
• /
• 제22권1호
• /
• pp.60-66
• /
• 1985

Hard shaped bodies are made by sintering a cold-pressed compact of a boron carbide compound which contains a densification aid. Titanium diboride and carbon were used as a densification aid in a range of 1% to 10% by weight. The effects of sintering temperature and additives on linear shrinkage porosity hardness bend strength and microstructure were examined. The initial partical size dependence on the sintered density was also discussed.

• 한국토양비료학회지
• /
• 제11권1호
• /
• pp.43-50
• /
• 1978

숙전(熟田) 토양(土壤)에 있어서 대두재배시(大豆在培時) 용인(熔燐), 붕사(硼砂) 입상용인(粒狀熔璘), 함붕소입상용인(含硼素粒狀熔燐), 복합비료(複合肥料) 및 함붕소복합비료(含硼素複合肥料)($B_2O_3$ 0.5, 1.0, 1.5%)의 시용(施用)이 대두함량(大豆收量)에 미치는 영향(影響)을 밝히고져 포장시험(圃場試驗)한 결과(結果)는 다음과 같다. 1. 용인형태별(熔燐形態別) 대두수량(大豆收量)을 보면 분상용인(粉狀熔燐), 입상용인((粒狀熔燐), 복합비료複合肥料)들 간(間)에는 차이(差異)가 인정(認定)되지 않았으나 무연산구(無憐酸區)에 비(比)해서는 모든 용인(熔燐) 시용구(施用區)들이 수량(收量)이 유의성(有意性)있게 높았다. 이로 미루어보아 본시험(本試驗)에 공시(供試)된 입상(粒狀) 용인(熔燐)은 분상(粉狀) 용인(熔燐)과 비(比)할 때 비효면에서 차이(差異)없는 것으로 볼 수 있다. 2. 붕소이용(硼素施用)은 무시용(無施用)에 비(比)해 유의성(有意性)있는 증수(增收)를 갖어 왔으며 분상용인(粉狀熔燐)에 붕사(硼砂)를 별도(別途)로 첨가(添加)하는 것보다는 함붕소입상용인(含硼素粒狀熔燐)의 형태(形態)로 시용(施用)하는 편(便)이 더 유리(有利)한 것으로 나타났고 함붕소복비(含硼素複肥)의 환경(境遇)에는 붕산함량(硼酸含量)이 1.5%는 되어야 하는 것으로 나타났다. 3. 붕소이용(硼素施用)은 내수(萊數)를 증가(增加)시키는 효과가 있었으며 식물체중(植物體中)의 붕소(硼素), 가리(加里) 및 석회(石灰)의 농도(濃度)와 그 흡수량(吸收量)을 증가(增加)시키는 효과도 인정(認定)되었다. 4. 시험후(試驗後) 토양분석치(土壤分析値)를 보면 분상용인(粉狀熔燐), 입상용인(粒狀熔燐), 복합비료(複合肥料), 함붕소복합비료(含硼素複合肥料)들은 토양중(土壤中) 유효인산 함량(含量)을 높이는데 있어 차이(差異)가 없었으며 이런 경향(傾向)은 석회(石灰)나 고토(苦土)의 경우(境遇)에도 같았다. 5. 붕소이용(硼素施用)은 시험후(試驗後) 토양중(土壤中) 수용성(水溶性) 붕소함량(硼素含量)을 높인 傾向이었다.

• Journal of the Korean Wood Science and Technology
• /
• 제48권4호
• /
• pp.513-526
• /
• 2020

The existing preservation methods are difficult to be applied to a large dimension log which is needed for making traditional wooden ship 'Jalur' in Riau Province. Novel techniques to provide the use of readily available species to replace traditional species alternative were investigated. These included infusion and a combination of injection and bandage-wrapping methods for preserving living trees of Balam (Macaranga conifera (Rchb.f. & Zoll.) Müll.Arg.) and Bintangor (Calophyllum soulattri Burm.f.). Water-based boron compounds were applied as wood preservatives. In total, 18 discs from the bottom, middle, and top of four trees and two controls were used. Trees undergoing treatment were also used to see how wood anatomical structure might affect the boron penetration. The overall aim was to identify the best method for use in Jalur manufacturing. The results showed that in infused Balam tree where the hose position for the preservative intake was deep (10-15 cm from the bark), no boron compound was observed in the outer sapwood. Combination of injection and bandage-wrapping method gave higher percentage of boron penetration at bottom and middle of Balam tree. However, infused Bintangor showed 100% boron penetration. The larger vessel diameter, the absence of tyloses, and the simple perforation plates in Bintangor wood were likely to have contributed to the higher penetration of boron. The combination of bandage-wrapping and infusion, or alternatively by infusing the living trees close to the bark, and at as low as position in the stem gives better protection when treatments are applied to living trees.

• 공업화학
• /
• 제29권6호
• /
• pp.670-676
• /
• 2018

붕산, 5붕산암모늄, 붕산/5붕산암모늄 첨가제로 처리한 편백목재 시험편의 연소가스 발생에 관한 시험을 하였다. 15 wt%의 붕소 화합물 수용액으로 각각 편백목재 시험편에 붓으로 3회 칠하였다. 실온에서 건조시킨 후, 콘칼로리미터(ISO 5660-1)를 이용하여 연소가스를 분석하였다. 그 결과, 붕소화합물로 처리한 시험편의 연기성능지수(SPI)는 공시편 보다 1.37~2.68배 증가하였고, 연기성장지수(SGI)는 29.4~52.9% 감소하였다. 그리고 붕소화합물로 처리된 시험편의 연기강도(SI)는 공시편보다 1.16~3.92배 감소되어 연기 및 화재 위험성이 낮아지는 것으로 예상된다. 또한 붕소화합물로 처리한 시험편의 최대일산화탄소($CO_{peak}$) 농도는 공시편보다 12.7~30.9% 감소되었다. 그러나 미국직업안전위생관리국(OSHA) 허용기준(PEL)보다 1.52~1.92배 높은 치명적인 독성을 발생하는 것으로 측정되었다. 붕소화합물은 일산화탄소를 감소시키는 역할을 하였으나 편백목재 자체의 일산화탄소의 생성 농도가 높기 때문에 감소효과에 대한 기대에 미치지 못하였다.

• Transactions on Electrical and Electronic Materials
• /
• 제18권1호
• /
• pp.7-12
• /
• 2017

This work takes place in the context of the development of a transport phenomena simulation based on group III nitrides. Gallium and boron nitrides (GaN and BN) are both materials with interesting physical properties; they have a direct band gap and are relatively large compared to other semiconductors. The main objective of this paper is to study the effect of boron content on the electron transport of the ternary compound $B_xGa_{(1-x)}N$ and the effect of the temperature of this alloy at x=50% boron percentage, specifically the piezoelectric, acoustic, and polar optical scatterings as a function of the energy, and the electron energy and drift velocity versus the applied electric field for different boron compositions ($B_xGa_{(1-x)}N$), at various temperatures for $B_{0.5}Ga_{0.5}N$. Monte carlo simulation, was employed and the three valleys of the conduction band (${\Gamma}$, L, X) were considered to be non-parabolic. We focus on the interactions that do not significantly affect the behavior of the electron. Nevertheless, they are introduced to obtain a quantitative description of the electronic dynamics. We find that the form of the velocity-field characteristic changes substantially when the temperature is increased, and a remarkable effect is observed from the boron content in $B_xGa_{(1-x)}N$ alloy and the applied field on the dynamics of holders within the lattice as a result of interaction mechanisms.

• 대한금속재료학회지
• /
• 제46권6호
• /
• pp.329-337
• /
• 2008

During the continuous casting of boron-bearing steel, the corner cracks on the slab are formed by deformation with low strain rate and rapid cooling at the unbending temperature within the range of 800- $1000^{\circ}C$. Especially, the rapid cooling in the corner of slab during the continuous casting leads to as corner cracking. Therefore, in this study, the hot tensile tests applied to the different cooling rates were taken into account in order to study the effect of cooling rate on the hot ductility of boron-bearing steel. The results revealed that increasing cooling rate deteriorate the hot ductility of boron- bearing steel. Rapid decreasing of the hot ductility is caused by formation of a film-like ferrite and precipitate at the austenite grain boundaries. The morphology of the precipitates in the boron-bearing steel was monitored by PTA (Particle Tracking Autoradiography) and TEM, we observed MnS and BN compound and their morphology was quite different depending on the cooling rates. When the cooling rate is increased, rodshape MnS and BN precipitates can be formed along the austenite grain boundaries. It can cause that weakening the boundary region and decreasing the hot ductility of boron-bearing steel.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
• /
• pp.1033-1034
• /
• 2006

Metallic compound of ternary Al-B-C system was prepared by mechanical alloying (MA) using Al, boron and graphite powders as starting materials. MA was carried out using Spex 8000 mixer/mill for 50 hours in an argon atmosphere without process control reagent such as methyl alcohol. The MA powders obtained were heat-treated in vacuum at the temperature of 873 and 1273 K for 5 hour. Pure ternary Al-B-C compound was obtained in the chemical content of Al:B:C=55:27:18. The ternary compound obtained in this study has a new phase whose crystal structure is not identified yet.

• 통합자연과학논문집
• /
• 제10권3호
• /
• pp.171-174
• /
• 2017

Non-hydrolyzable fluorinated organosilicon compounds as an eletrolyte for the application of lithium-ion batteries (LIB) are synthesized. New synthetic method for the perfluorinated organosilicon compound containing spacer such as ethyl and propyl group with cyano moiety instead of ethylene glycol to prevent hydrolysis and to promote conductivity are developed in one pot reaction with moderately high yield. Air-sensitive boron trifluoride etherate is no longer required in this reaction. The products are characterized by spectroscopic analysis.

• 한국레이저가공학회지
• /
• 제13권3호
• /
• pp.19-26
• /
• 2010

In this study, fundamental experiment was conducted with various strength of UHSS (Ultra High Strength Steel) by $CO_2$ laser. And then, butt and lap joint laser welding with boron alloyed steel and Al-Si coated boron alloy steel have been done by changing laser beam feature, existence of gap and existence of coating layer to know welding characteristics of those materials. As a result, in case of fundamental experiment with various strength steel, hardening was found in the weld metal of all tested materials and softening was found at the heat affected zone of SGAFC 1180. In case of laser butt welding of UHSS, mechanical properties was improved by using small laser beam diameter and Al-Si coating layer caused fracture of weld metal. In case of laser lap welding of UHSS, Al-Si coating layer resulted in formation of intermetallic compound at the fusion boundary where fracture occurred. Al-Si coating layer caused lowering mechanical properties of weld metal.

• 콘크리트학회논문집
• /
• 제29권1호
• /
• pp.85-92
• /
• 2017

본 연구에서는 붕소화합물을 혼입하여 제작한 모르타르의 특성에 대한 검토를 수행하였다. 사용된 붕소화합물은 pH 값에 따라 산성 및 약알칼리성, 강알칼리성으로 구분하여 선별한 것으로 산성 기반인 붕산(AA)과 약알칼리 기반의 붕사(AB), 강알칼리성인 붕사(HB)이다. 실험은 모르타르의 물리적 화학적 특성을 파악할 수 있는 pH 측정 및 응결 시험, 압축강도 시험을 수행하였으며 모르타르 내 미세구조 분석을 위해 SEM 촬영을 수행하였다. pH 측정 결과 붕소화합물을 혼입한 시험체 전반적으로 기본 모르타르보다 pH가 낮게 측정되었으며 시간이 지남에 따라 pH가 저하되는 양상을 보였다. 또한, 응결 시험에서도 기본 시험체보다 초결 및 종결 시점이 늦게 발생되었으며 알칼리도에 따라 응결 지연을 저감할 수 있다는 기존 문헌과 다소 다른 결과를 나타냈다. 압축 강도 및 SEM 촬영 결과, 붕소화합물의 종류 및 성분에 따라 강도 등의 물리적 성능이 결정되기 때문에 이를 고려하여 최적 혼입량을 결정하는 것이 바람직할 것으로 판단된다.