• 제목/요약/키워드: boron effect

검색결과 390건 처리시간 0.022초

보론 첨가 저탄소합금강에서 Mn함량과 오스테나이트 결정입도가 경화능에 미치는 영향에 관한 연구 (Study on the Effect of Austenite Grain Size and Mn Content on Hardenability in Boron-added Low Carbon alloys Steels)

  • 허웅렬;노용식;최문성;김영희;이상윤
    • 열처리공학회지
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    • 제3권4호
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    • pp.23-40
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    • 1990
  • This study has been carried out to investigate into some effects of Mn content with varying amounts and austenite grain size on hardenability in boron-added Fe-C-Cr-Mo alloy systems. (1) Austenite grains have been found to hardly grow in the temperature range of $900^{\circ}C$ to $950^{\circ}C$, whereas they grow rapidly in the temperature range of $975^{\circ}C$ to $1100^{\circ}C$. (2) Austenite grain growth is considerably small with increasing holding time at a given austenitizing temperature and is, in particular, hardly found to occur at a temperature of $900^{\circ}C$. (3) The hardenability improves ramarkably as Mn content is increased at three different austenitizing temperatures $900^{\circ}C$, $1000^{\circ}C$ and $1100^{\circ}C$. (4) The maximum hardenability is obtained from steels A, B and C austenitized at the $900^{\circ}C$, although Mn content is varied in each specimen.

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In-situ 고온 딜라토미터를 이용한 탄화붕소의 소결거동 연구 (A Study of the Sintering Behavior of Boron Carbide using In-situ High Temperature Dilatometer)

  • 이혁재;김범섭;정태주
    • 한국분말재료학회지
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    • 제21권2호
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    • pp.102-107
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    • 2014
  • A high temperature dilatometer attached to a graphite furnace is built and used to study the sintering behavior of $B_4C$. Pristine and carbon doped $B_4C$ compacts are sintered at various soaking temperatures and their shrinkage profiles are detected simultaneously using the dilatometer. Carbon additions enhance the sinterability of $B_4C$ with sintering to more than 97% of the theoretical density, while pristine $B_4C$ compacts could not be sintered above 91% due to particle coarsening. The shrinkage profiles of $B_4C$ reveal that the effect of carbon on the sinterability of $B_4C$ can be seen mostly below $1950^{\circ}C$. The high temperature dilatometer delivers very useful information which is impossible to obtain with conventional furnaces.

채널구조와 바이어스 조건에 따른 Si0.8Ge0.2 pMOSFET의 저주파잡음 특성 (Low-frequency Noise Characteristics of Si0.8Ge0.2 pMOSFET Depending upon Channel Structures and Bias Conditions)

  • 최상식;양현덕;김상훈;송영주;이내응;송종인;심규환
    • 한국전기전자재료학회논문지
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    • 제19권1호
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    • pp.1-6
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    • 2006
  • High performance $Si_{0.8}Ge_{0.2}$ heterostructure metal-oxide-semiconductor field effect transistors (MOSFETs) were fabricated using well-controlled delta-doping of boron and $Si_{0.8}Ge_{0.2}$/Si heterostructure epitaxal layers grown by reduced pressure chemical vapor deposition. In this paper, we report 1/f noise characteristics of the SiGe pMOSFETs measured under various bias conditions of the gate and drain voltages changing in linear operation regions. From the noise spectral density, we found that the gate and drain voltage dependence of the noise represented same features, as usually scaled with $f^{-1}$ However, 1/f noise was found to be much lower in the device with boron delta-doped layer, by a factor of $10^{-1}_10^{-2}$ in comparison with the device fabricated without delta-doped layer. 1/f noise property of delta-doped device looks important because the device may replace bipolar transistors most commonly embedded in high-frequency oscillator circuits.

Chlorella 의 물질대사에 미치는 미양원소의 결핍효과 1 (제 1 ) -생 및 광합성 에 관하여- (Effect of micronutritional-element deficienies on the metabolism of Chlorella cells. (I) -On the growth rate, respiation and photosynthesis-)

  • 이영록;진평;심웅섭
    • 미생물학회지
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    • 제5권1호
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    • pp.15-19
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    • 1967
  • Chlorella ellipsoidea cells were cultured in an iron, copper, zinc, manganese, molybdenum or boron-free medium. Physiological activities such as growth rate, reproduction, endogenous and glucose respiration, photosynthetic activity and biosythesis of chlorophyll of the micro-element definition cells were measured. It generally, growth rate, respiratory and photosynthetic activities, and biosynthesis of chlorophyll of the micro-element deficient cells decreased more or less, compared with those of the normal cells. The growth of the algal cells in an iron-free medium were retarded severely with the chlorosis, and the photosynthetic activity of the cells decreased remarkably even though the low content of chlorophyll in the cells owing to the iron-deficiency is considered. Therefore, it is deduced that iron takes part in the photosynthetic process itself, possibly by its participation in the photo phosphorylation coupled with electron transport. Respiratory activity of boron-deficient cells showed the most severe decrease whereas those of the molybdenum-deficient cells showed very slight decrease in spite of severe growth retardation.

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SiGe pMOSFET의 채널구조와 바이어스 조건에 따른 잡음 특성 (Low-Frequency Noise Characteristics of SiGe pMOSFET Depending upon Channel Structures and Bias Conditions)

  • 최상식;양현덕;김상훈;송영주;조경익;김정훈;송종인;심규환
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.5-6
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    • 2005
  • High performance SiGe heterostructure metal-oxide-semiconductor field effect transistors(MOSFETs) were fabricated using well-controlled delta-doping of boron and SiGe/Si heterostructure epitaxal layers grown by reduced pressure chemical vapor deposition. In this paper, we report 1/f noise characteristics of the SiGe MOSFETs measured under various bias conditions of the gate and drain voltages changing in linear operation regions. From the noise spectral density, we found that the gate and drain voltage dependence of the noise represented same features, as usually scaled with $f^1$. However, 1/f noise was found to be much lower in the device with boron delta-doped layer, by a factor of $10^{-1}\sim10^{-2}$ in comparion with the device fabricated without delta-doped layer. 1/f noise property of delta-doped device looks important because the device may replace bipolar transistors most commonly embedded in high-frequency oscillator circuits.

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In vitro Inhibition Effect of Plant Extracts, Urine, Fertilizers and Fungicides on Stem Rot Pathogen of Sclerotium rolfsii

  • Alam, Shahidul;Islam, M. Rafiqul;Sarkar, Montaz Ali;Alam, M.S.;Han, Kee-Don;Shim, Jae-Ouk;Lee, Tae-Soo;Lee, Min-Woong
    • Mycobiology
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    • 제32권3호
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    • pp.128-133
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    • 2004
  • Twenty plant extracts were tested against mycelial growth, sclerotium formatiom and dry weight of mycelium with sclerotia of Sclerotium rolfsii Sacc. The highest(90 mm) mycelial growth was measured in Adhatoda vasica, Tegetes erecta, Allium cepa, and Curcuma longa. The lowest(25 mm) was in Azadirachta indica. No mycelial growth was found in any concentration of cow, buffalo, and goat urine. The highest(90 mm) and the lowest(15 mm) mycelial growth were measured in Biomil and Urea, respectively. No mycelial growth was observed in Zinc. The highest(60 mm) and the lowest(2 mm) mycelial growth were recorded in Macuprex(Dodine; 65% WP) and Boron(100% Boric acid and 17% Boron) respectively. Mycelial growth was totally inhibited in Rovral(Iprodione; 50% WP).

기수지역 선박평형수의 염소 생성 효율에 미치는 전기화학 처리의 영향 (Effect of Electrochemical Treatment on the Chlorine Generation Efficiency of Ballast Water in the Brackish Zone)

  • 최용선;이유기
    • 한국재료학회지
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    • 제29권1호
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    • pp.16-22
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    • 2019
  • Indirect oxidation using chlorine species oxidizing agents is often effective in wastewater treatment using an electrochemical oxidation process. When chlorine ions are contained in the wastewater, oxidizing agents of various chlorine species are produced during electrolysis. In a ballast water management system, it is also used to treat ballast water by electrolyzing seawater to produce a chlorine species oxidizer. However, ballast water in the brackish zone and some wastewater has a low chlorine ion concentration. Therefore, it is necessary to study the chlorine generation current efficiency at various chlorine concentration conditions. In this study, the chlorine generating current efficiency of a boron-doped diamond(BDD) electrode and insoluble electrodes are compared with various chloride ion concentrations. The results of this study show that the current efficiency of the BDD electrode is better than that of the insoluble electrodes. The chlorine generation current efficiency is better in the order of BDD, MMO(mixed metal oxide), $Ti/RuO_2$, and $Ti/IrO_2$ electrodes. In particular, when the concentration of sodium chloride is 10 g/L or less, the current efficiency of the BDD electrode is excellent.

64M DRAM의 Defect 관련 STI(Shallow Trench Isolated) NMOSFET Hump 특성 (Hump Characteristics of 64M DRAM STI(Shallow Trench Isolated) NMOSFETs Due to Defect)

  • 이형주
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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    • pp.291-293
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    • 2000
  • In 64M DRAM, sub-1/4m NMOSFETs with STI(Shallow Trench Isolation), anomalous hump phenomenon of subthreshold region, due to capped p-TEOS/SiN interlayer induced defect, is reported. The hump effect was significantly observed as channel length is reduced, which is completely different from previous reports. Channel Boron dopant redistribution due to the defect should be considered to improve hump characteristics besides consideration of STI comer shape and recess.

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반데르발스 2차원 반도체소자의 응용과 이슈 (Trend and Issues of van der Waals 2D Semiconductor Devices)

  • 임성일
    • 진공이야기
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    • 제5권2호
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    • pp.18-22
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    • 2018
  • wo dimensional (2D) van der Waals (vdW) nanosheet semiconductors have recently attracted much attention from researchers because of their potentials as active device materials toward future nano-electronics and -optoelectronics. This review mainly focuses on the features and applications of state-of-the-art vdW 2D material devices which use transition metal dichalcogenides, graphene, hexagonal boron nitride (h-BN), and black phosphorous: field effect transistors (FETs), complementary metal oxide semiconductor (CMOS) inverters, Schottky diode, and PN diode. In a closing remark, important remaining issues of 2D vdW devices are also introduced as requests for future electronics and photonics applications.

Anomalous Subthreshold Characteristics of Shallow Trench-Isolated Submicron NMOSFET with Capped p-TEOS/SiN

  • Lee, Hyung J.
    • Transactions on Electrical and Electronic Materials
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    • 제3권3호
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    • pp.18-20
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    • 2002
  • In sub-l/4 ${\mu}{\textrm}{m}$ NMOSFET with STI (Shallow Trench Isolation), the anomalous hump phenomenon of subthreshold region, due to capped p-TEOS/SiN induced defect, is reported. The hump effect was significantly observed as channel length is reduced, which is completely different from previous reports. Channel boron dopant redistribution due to the defect should be considered to improve hump characteristics besides considerations of STI comer and recess. 130