• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.146-149
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• 2007

The effects of boron additions in steels have long been recognized as very important, mainly with respect to hardnability of heat treatable steels. The systematics of structure and properties of boron steels will then be illustrated in the context of low-alloy steels with carbon contents raging from 0.05 to 0.25% and boron contents 0-130 ppm. we investigated the effect of the microstructure and mechanical properties with heat treatment condition of the boron-treated(0.0013 ppm) low carbon(0.2 %C) low alloy steel. The specimens were austenitised for 5 and 10, 15 min at $880{\sim}940^{\circ}C$(with/without tempered at 150, 180 and $210^{\circ}C$ for the various periods of time from 60 min to 120 min) After heat treatment, mechanical properties were measured by tensile test and hardness test. For analysis of microstructure, Optical/SEM analysis and XRD were carried out.

• Mass Spectrometry Letters
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• v.12 no.1
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• pp.26-30
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• 2021

The impurity concentration is a crucial parameter for semiconductor thin films. Evaluating the impurity distribution in silicon thin film is another challenge. In this study, we have investigated the doping concentration of boron in silicon thin film using time of flight secondary ion mass spectrometry in dynamic mode of operation. Boron doped silicon film was grown on i) p-type silicon wafer and ii) borosilicate glass using hot wire chemical vapor deposition technique for possible applications in optoelectronic devices. Using well-tuned SIMS measurement recipe, we have detected the boron counts 101~104 along with the silicon matrix element. The secondary ion beam sputtering area, sputtering duration and mass analyser analysing duration were used as key variables for the tuning of the recipe. The quantitative analysis of counts to concentration conversion was done following standard relative sensitivity factor. The concentration of boron in silicon was determined 1017~1021 atoms/㎤. The technique will be useful for evaluating distributions of various dopants (arsenic, phosphorous, bismuth etc.) in silicon thin film efficiently.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.3
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• pp.139-143
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• 2017

N-type crystalline silicon solar cells have high metal impurity tolerance and higher minority carrier lifetime that increases conversion efficiency. However, junction quality between the boron diffused layer and the n-type substrate is more important for increased efficiency. In this paper, the current status and prospects for boron diffused layers in N-type crystalline silicon solar cell applications are described. Boron diffused layer formation methods (thermal diffusion and co-diffusion using $a-SiO_X:B$), boron rich layer (BRL) and boron silicate glass (BSG) reactions, and analysis of the effects to improve junction characteristics are discussed. In-situ oxidation is performed to remove the boron rich layer. The oxidation process after diffusion shows a lower B-O peak than before the Oxidation process was changed into $SiO_2$ phase by FTIR and BRL. The $a-SiO_X:B$ layer is deposited by PECVD using $SiH_4$, $B_2H_6$, $H_2$, $CO_2$ gases in N-type wafer and annealed by thermal tube furnace for performing the P+ layer. MCLT (minority carrier lifetime) is improved by increasing $SiH_4$ and $B_2H_6$. When $a-SiO_X:B$ is removed, the Si-O peak decreases and the B-H peak declines a little, but MCLT is improved by hydrogen passivated inactive boron atoms. In this paper, we focused on the boron emitter for N-type crystalline solar cells.

• Journal of Environmental Health Sciences
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• v.44 no.6
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• pp.556-562
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• 2018

Objectives: This study was conducted to investigate the boron concentrations in 30 slime products and estimate children's dermal exposure to boron. Methods: Thirty slime products from online and offline stores were purchased for boron analysis. The boron content of each slime sample was analyzed using ICP-OES. A nationwide survey was performed to determine use patterns of slimes by a home-visit survey of 10,000 children divided into three age groups: 0-2, 3-6, and 7-12 years. The dermal exposure to boron was calculated using an exposure algorithm for child slime users. Results: The proportion of the child population using slime was 45.8%, and the mean use frequency was $2.5{\pm}3.8$ per week (range: 0.08-35). Mean time spent playing with slime was $19.6{\pm}11.3min$ (range: 1-100). Twenty-five of the thirty slimes contained a boron concentration exceeding the EU limit for toys made with sticky material of 300 mg/kg. Dermal exposure ranged from $0.0008-13.78{\mu}g/kg/day$ with the maximum weight fractions of boron in the 30 products. The dermal exposure estimate was the highest in 7-12 years old group. Conclusion: Slime use among Korean children may cause high exposure to boron. Regulation is needed to minimize boron exposure from slime products.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.91-94
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• 2008

Newly developed Atom Probe Tomography (APT) technique can provide the highest available spatial resolution, 3D tomography imaging and quantitative chemical analysis in a sub-nm scale. As a complementary technique to APT, Nano-secondary ion Mass Spectroscopy (SIMS) also provides the boron distribution in micro-scale. Therefore, the exact behavior of boron at either grain boundary or grain interior in steels can be investigated by the combination of APT and SIMS techniques from the sub-nanometer scale to the micrometer scale. The results obtained by both APT and SIMS revealed that the boron atoms were mainly segregated to the grain boundaries rather than to the grain interior in the steels containing 50ppm and 100ppm boron. It also found that carbon atoms were segregated at the boron enriched regions, which were thought to be retained austenite phase due to the chemical composition of carbon atoms.

• Corrosion Science and Technology
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• v.19 no.1
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• pp.1-7
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• 2020

Chalk River Unidentified Deposits (CRUDs) were collected from the Korean pressurized water reactor (PWR) plant (A, B, and C) where the axial offset anomaly (AOA) occurred. AOA, also known as a CRUD-induced power shift, is one of the key issues in maintaining stable PWR plant operations. CRUDs were sampled from spent nuclear fuel rods and analyzed using an electron probe micro-analyzer (EPMA). This paper describes the characteristics of boron-deposits from the CRUDs sampled from twice-burnt assemblies from the Korean PWR. The primary coolant of a PWR contains boron and lithium. It is known that boron deposition occurs in a thick CRUD layer under substantial sub-cooled nucleate boiling (SNB). The results of this study are summarized as follows. Boron was not found at the locations where the existence was confirmed in simulated CRUDs, in other words, the cladding and CRUD boundaries. Nevertheless, we clearly observed the presence of boron and confirmed that boron existed as a lump in crystalline form. In addition, the study confirmed that CRUD existed in a crystal form with a unique size of about 10 ㎛.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.3
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• pp.97-102
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• 2009

The use of deep water as drinking water is greatly limited of significant concentration of boron in sea water. Boron is reported to be toxic for human and plants. Some of possible methods are available to remove boron. The polymeric resins were synthesized to remove the boron from the sea water. The resin was characterized with IR analysis and the morphology was discussed with SEM images. To assess boron removal capacity of the resin, it was distributed in three different bead size i.e., 0.25mm, 0.5mm and 1.0mm. The removal behavior of this resin was examined under the batch experiments.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.4
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• pp.195-198
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• 1975

Boron deficiency appeared as a cause of poor growth of sunflower(Helianthus annuus) according to soil and plant analysis. The investigated results are as follows; 1. Boron deficiency was due to low content of available boron (hot water soluble) in soil and clitical concentration appeared as 0.17 ppm. 2. Clitical concentrations in plant appeared to be 20 ppm for head(flower), 25 for leaf, 15 for stem and 10 for root. Boron concentration among positional leaves was greatly decreasing in the upper leaves. 3. Soils low in boron were relatively higher in calcium, silica and pH than in normal soil but relationship between boron and organic matter or other nutrients was uncertain. 4. The content of Ca and P is high in the head of boron deficient plant but low in root. Plants deficient in boron also showed a tendency of high N and low K but no clear tendency was shown in Mg and Fe. 5. Symptoms of boron deficinicy were yellowing of upper leaves, browning and drying of upper part of stem, cracking and blackening of stem and roots resulting short stem and poor growth.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.99-100
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• 2006

$BF_2$ molecule 이온주입은 ULSI기술에 있어서 ultra shallow 정합형성을 위해고 P-MOS를 제작하는데 매우 유용한 기술이다. 주입된 boron 이온의 분포를 위해서 $0.05{\mu}m$ 나노스케일의 마스크사이즈의 패턴에 이온 주입한 결과를 일차원적인 분포해석을 위해서 UT-Marlowe tool을 사용하여 gauss 및 pearson 모델의 도핑분포를 나타내었다. 또한 이 데이터를 TSUPREM4에 적용하여 이차원적인 도핑분포와 열처리 후에 boron의 gauss 및 pearson의 모델의 도핑분포를 본 논문에 나타내었다.

• Fibers and Polymers
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• v.2 no.4
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• pp.190-195
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• 2001

Additives, such as sodium perborate and borax, were examined in dialdehyde wrinkle resistant finishing of cotton. Results indicated that the whiteness index(WI) of cotton treated with dialdehyde and additive showed about 90% of WI of the untreated cotton but with decrease in wrinkle recovery angle (WRA) due to inhibition effect of these additives. Effect of additive on the WRA reduction was more prominent with glutaraldehyde than with glyoxal. Reduction in WRA of cotton treated with both dialdehydes and boron compound was minimized by simultaneous addition of formic acid in the bath. Addition of formic acid was also generally beneficial in maintaining WI retentions after 8 months storage. Furthermore, boron compounds were also effective in improving retentions of mechanical properties. By FTIR analysis the residual aldehyde group was detected on the dialdehyde-finished cotton, whereas no peak was shown by addition of boron compounds. This suggested that the residual aldehyde group was a main cause of fabric yellowing on the dialdehyde-finished cotton. Dialhehyde with boron compound, therefore, can be used to replace a conventional formaldehyde-containing wrinkle resistant finishing of cotton.