• Title/Summary/Keyword: boron effect

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Reactor core design with practical gadolinia burnable absorbers for soluble boron-free operation in the innovative SMR

  • Jin Sun Kim;Tae Sik Jung;Jooil Yoon
    • Nuclear Engineering and Technology
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    • v.56 no.8
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    • pp.3144-3154
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    • 2024
  • The development of soluble boron-free (SBF) operation in the innovative Small Modular Reactor (i-SMR) requires effective strategies for managing excess reactivity over extended operational cycles. This paper introduces a practical approach to reactor core design for SBF operation in i-SMR, emphasizing the use of gadolinia burnable absorbers (BA). The study investigates the feasibility of Highly Intensive and Discrete Gadolinia/Alumina Burnable Absorber (HIGA) rods for controlling excess reactivity sustainably. Through comprehensive analysis and simulations, the reactivity behavior with varying quantities of HIGA rods is examined, leading to the development of optimized fuel assembly designs. Furthermore, the integration of HIGA rods with integral gadolinia BA rods is discussed to enhance reactivity control and operational flexibility further. This approach utilizes the spatial self-shielding effect of gadolinia for extended reactivity management, crucial for stable and efficient reactor performance. The paper thoroughly addresses core design considerations, including fuel assembly configurations and control rod patterns, to ensure safety and performance in initial and reload cycles. This research advances the development of SBF operation in i-SMR by offering practical reactivity management solutions.

Effect of Boron Contained Compound Fertilizer on Chestnut Trees (밤나무 전용복비(專用複肥) 비효시험(肥效試驗))

  • Maeng, Do-Weon;Chung, In-Ku
    • Korean Journal of Soil Science and Fertilizer
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    • v.16 no.3
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    • pp.250-255
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    • 1983
  • Newly manufactured compound fertilizers for chestnut trees developed by Chosun Fertilizer Inc. were tested to evaluate their effectiveness. An experiment was carried out in chestnut farm with 4 years old Eungi Var. from 1981 to 1982. The results obtained are as follows: 1. The growth of chestnut trees was generally good in plots of compound fertilizer contained boron (B C F). 2. The number of ripened strobiles was significantly increased by reducing the ratio of dropped strobiles in plot of B C F. 3. The yield of chestnut by B C F was markedly increased, 6 times more than that of compound fertilizer without boron. 4. Boron content in soil and plant by application of B C F was relatively high, resulting in high production of chestnut. 5. B C F was effective in chestnut orchard to increase nut production markedly.

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Effect of Hot-Stamping on Mechanical Properties and Microstructures of CO2 Laser Welded Boron Steel coated with Al-Si layer (Al-Si 용융 도금된 보론강 CO2 레이저 용접부의 미세조직과 기계적 성질에 미치는 핫스탬핑 처리의 영향)

  • Oh, Myeonghwan;Kong, Jongpan;Shin, Hyeonjeong;Kwon, Minsuck;Jung, Byunghun;Kang, Chungyun
    • Laser Solutions
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    • v.16 no.3
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    • pp.1-10
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    • 2013
  • In this study, Al-Si coated boron steel(1.2 mm) were laser welded by $CO_2$ laser and hot-stamping was applied to the laser joints. Tensile properties and microstructures of the joints were investigated before and after hot-stamping. Tensile and yield strengths of the as welded specimen similar with base metal and fracture occurred base metal of boron steel. Although, in case of heat treated specimen, fracture occurred fusion zone that Al segregated zone near the bond line. These could be explained by the existence of ferrite, in the Al segregated zone near the bond line and base metal of boron steel. Before hot-stamping, hardness of base metal is lower than fusion zone and heat affected zone in spite of exist Al segregation zone($Fe_3$(Al,Si)). So fracture occurred base metal. Although, after hot-stamping, microstructure of base metal and welds zone transformed to martensite and bainite except in Al segregation zone near the bond line that $Fe_3$(Al,Si) transformed to a-ferrite. So fracture occurred Al segregation zone near the bond line.

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Effect of micronutritional-element deficiencies on the metabolism of Chlorella cells. (II) On the biosynthetic activities of protein, nucleic acids and phospholipid (Chlorella 의 물질대사에 미치는 미양원소의 결핍효과(제 2 ) -, 리보 및 의 생합성능에 관하여-)

  • Lee, Yung-Nok;Chin, Pyung;Sim, Woong-Seop
    • Korean Journal of Microbiology
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    • v.6 no.1
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    • pp.22-28
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    • 1968
  • Chlorella ellipsoidea cells were cultured in an iron, copper, zinc, manganese, molybdenum or boron-free medium. Biosynthetic activities of nucleic acids, protein and phospholipid in chlorella cells, which were growing in a microelement deficient medium were compared with those of the normal cells by measuring the contents of phosphate, amino acids or UV-absorbing substances in the various cell fractions. When the algae were grown in a molybdenum-free medium, the amounts of phosphate in the acid-soluble fraction of the cells increased, whereas the amounts of alkali-stable protein and RNA decreased compared with the normal cells showing that the synthesis of protein and RNA from the early products of photosynthesis was inhibited. When the algae were grown in a boron-free medium, amounts of alkali-labile protein and phospholipid of the cells decreased, while the amount of phosphate in acid-soluble fraction increased compared with the normal cells showing that the biosynthesis of protein and phospholipid from the early products of photosynthesis was retarded. In general, amounts of protein and RNA in the microelement deficient cells significantly decreased compared with those of the normal cells. Phosphate content in the acid-soluble fraction of the algal cell grown in an zinc, copper, molybdenum, or boron-free medium increased considerably, whereas that of the algal cell grown in an iron or manganese-free medium decreased remarkably compared with that of the control. It is considered, therefore, that molybdenum, zinc, copper and boron etc. play an important role in the biosyntbesis of macromolecule from acid-soluble phosphate compounds, in contrast to the principal action of iron and manganese on the photosynthetic process itself.

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The Effect of Boron Doped CdS Film on CdS/CdTe Solar Cell (CdS 박막의 boron doping에 따른 CdS/CdTe 태양전지 특성)

  • Lee, H.Y.;Lee, J.H.;Kim, J.H.;Park, Y.K.;Shin, J.H.;Shin, S.H.;Park, K.J.
    • Proceedings of the KIEE Conference
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    • 1998.07d
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    • pp.1370-1372
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    • 1998
  • Boron doped CdS films were prepared by CBD(Chemical Bath Deposition) method using boric acid ($B_3HO_3$) as donor dopant source, and their properties were investigated. As-grown CdS films were highly adherent and specularly reflective. Boron doped CdS film which was fabricated under the condition of 0.01 $B_3HO_3/Cd(Ac)_2$ mole ratio, exhibited the lowest resistivity of $2{\Omega}cm$ and the highest optical bandgap of 2.41eV. Also, CdS/CdTe solar cells were fabricated with various doping concentration of CdS films. Using optimized CdS film as the window layer of CdS/CdTe solar cell, the characteristics of the cell were improved. ( $V_{oc}$=610mV, $J_{sc}$=37.5mA/cm, FF=0.4, $\eta$=9.1% )

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Enhanced Electrochemical Properties of NCA Cathode Materials for Lithium Ion Battery by Doping Effect (도핑효과에 따른 리튬이차전지용 NCA 양극활물질의 전기화학적 특성 향상)

  • Fan, Zhi Yu;Jin, n Mei;Jeong, Sang Mun
    • Korean Chemical Engineering Research
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    • v.55 no.6
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    • pp.861-867
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    • 2017
  • In order to improve the capacity and cycling stability of Ni-rich NCA cathode materials for lithium ion batteries, the boron and cobalt were doped in commercial $Li_{1.06}Ni_{0.91}Co_{0.08}Al_{0.01}O_2$ (NCA) powders. Commercial NCA particles are mixed composites such as secondary particles of about $5{\mu}m$ and $12{\mu}m$, and the particle size was decreased by doping boron and cobalt. The initial discharge capacities of the boron and cobalt doped NCA-B and NCA-Co were found to be 214 mAh/g and 200 mAh/g, respectively, which are higher values than that of the raw NCA cathode material. In particular, NCA-Co exhibits the best discharge capacity of 157 mAh/g after 20 cycles, which is probably due to the enhanced diffusion of lithium ion by crystal growth along with the c-axis direction.

A Study on the Development of Porcelain Bonded Ni-Cr Dental Alloy (도재소부용 Ni-Cr 보철합금 개발에 관한 연구)

  • Lee, Gyu-Hwan;Sin, Myeong-Cheol;Choe, Bu-Byeong
    • Journal of Biomedical Engineering Research
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    • v.6 no.1
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    • pp.37-46
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    • 1985
  • Development of a dental Ni-Cr alloy system for porcelain veneering crown and bridge was studied in this research. The principles of alloy design were a) It should not contain toxic beryllium. b) It should have low melting Point. c) It should be easily ground and polished. d) It should possess an adequate strength to resist the deformational force In the mouth. e) It should be bondable Ivith porcelain by chemically. After investigating the effect of minor elements such as boron and rare earth metals on the mechanical properties of the Ni-Cr alloy system, the compromised ideal composition for dental use was determined. The composition was l9.6%, Cr, 5.6% Mo, 3.4% Si, 1, 0% Fe, 0.01% Ti, 0.5-1.0% B, 0.2-0.6% misch metal, balance Ni. To compare the performance of experimental alloy with commercially available alloys, the properties such as strength, melting point, and bond strength were measured. The results Ivere as follows: a) Boron increases the strength of the alloy but reduces the elongation. b) Misch metal increases the strength when the boron content is low, but does not increase the strength when boron content is high. And it reduces the elongation drastically, c) Mechanical strength of the experimental alloy was not superior to commercially available Be containing alloy, but handling performance such as castability, ease of granting and polishing, and cuttability were superior to the Be containing alloy.

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Characteristics of Mechanical Properties and Micro Structure according to High-Frequency Induction Heating Conditions in Roll Forming Process of a Sill Side Part (실사이드 부품의 롤포밍공정에서 고주파유도가열 부가조건에 따른 기계적 특성 및 미세조직 평가)

  • Kim, Kun-Young;Choy, Lee-Jon;Shin, Hyun-Il;Cho, Jun-Haeng;Lee, Chang-Hoon;Kang, Myung Chang
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.6
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    • pp.87-94
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    • 2017
  • Hot stamping processes are possible for tensile strength 1.4 GPa but the strength reduction is appeared from the cooling performance unbalance. And the strength of roll forming process is below than that of hot stamping process owing to using the steel which is lower strength of boron steel. In this study, We provide roll forming process asssisted high-frequency induction heating to solve the problem of conventional one. The experiments were carried out at under various sill side part conditions: high-frequency induction heating conditions of 15, 18, 21, 24, 27 and 30 kW. The high-frequency induction heating temperature was checked with Infrared camera and the sill side parts of mechanical properties and microstructure were measured. The heating temperature of high frequency induction was measured to max $850^{\circ}C$ under the coil power of 30 kW. The tensile strength was 1.5 GPa and hardness was 490 Hv. The martensite structure was discovered under coil power of 30 kW. The weight of steel material sill side having thickness 1.5 mm and the boron steel sill side having thickness 1.2 mm were compared to weight effect. The boron steel sill side reduced 11.5% compared to steel. Consequently, manufacturing process of 1.5 giga-grade's sill side part was successfully realized by the roll forming assisted high-frequency induction heating methods.

The Effect of Boron Content and Deposition Temperature on the Microstructure and Mechanical Property of Ti-B-C Coating Prepared by Plasma-enhanced Chemical Vapor Deposition (PECVD법에 의해 증착된 Ti-B-C코팅막 내의 보론함량과 증착온도에 따른 미세구조 및 기계적 물성의 변화)

  • Ok, Jung-Tae;Song, Pung-Keun;Kim, Kwang-Ho
    • Journal of the Korean institute of surface engineering
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    • v.38 no.3
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    • pp.106-111
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    • 2005
  • Ternary Ti-B-C coatings were synthesized on WC-Co and Si wafers substrates by a PECVD technique using a gaseous mixture of $TiCl_4,\;BCl_3,\;CH_4,\;Ar,\;and\; H_2$. The effects of deposition variables such as substrate temperature, gas ratio, $R_x=[BCl_3/(CH_4+BCl_3)]$ on the microstructure and mechanical properties of Ti-B-C coatings were investigated. From our instrumental analyses, the synthesized Ti-B-C coatings was confirmed to be composites consisting of nanocrystallites TiC, quasi-amorphous TiB2, and amorphous carbon at low boron content, on the contrary, nanocrystallites $TiB_2$, quasi-amorphous TiC, and amorphous carbon at relatively high boron content. The microhardness of the Ti-B-C coatings increased from $\~23 GPa$ of TiC to $\~38 GPa$ of $Ti_{0.33}B_{0.55}C_{0.11}$ coatings with increasing the boron content. The $Ti_{0.33}B_{0.55}C_{0.11}$ coatings showed lower average friction coefficient of 0.45, in addition, it showed relatively better wear behavior compared to other binary coatings of $TiB_2$ and TiC. The microstruture and microhardness value of Ti-B-C coatings were largely depend on the deposition temperature.

Improvement of Thermal Conductivity of Poly(dimethyl siloxane) Composites Filled with Boron Nitride and Carbon Nanotubes (보론 나이트라이드와 탄소나노튜브로 충전된 실리콘 고무의 열전도도 향상)

  • Ha, Jin-Uk;Hong, Jinho;Kim, Minjae;Choi, Jin Kyu;Park, Dong Wha;Shim, Sang Eun
    • Polymer(Korea)
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    • v.37 no.6
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    • pp.722-729
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    • 2013
  • In order to enhance the thermal conductivity of poly(dimethyl siloxane) (PDMS), boron nitride (BN) and carbon nanotubes (CNTs) were incorporated as the thermally conductive fillers. The amount of BN was increased from 0 to 100 phr (parts per hundred rubber) and the amount of CNTs was increased from 0 to 4 phr at a fixed amount of the boron nitride (100 phr). The thermal conductivity of the composites increased with an increasing concentration of BN, but the incorporation of CNTs had only a slight effect on the enhancement of thermal conductivity. Unexpectedly, the thermal degradation of the composites was accelerated by the addition of CNTs in 100 phr BN filled PDMS. Activation energy for thermal decomposition of the composites was calculated using the Horowitz-Metzger method. The curing behavior, electrical resistivity, and mechanical properties of PDMS filled with BN and CNTs were investigated.