• 한국표면공학회지
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• 제33권4호
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• pp.222-228
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• 2000

The life time of cutting tool was studied in the relation with the properties of TiN coating tools. The purpose of this study is to compare the cutting conditions of the TiN coated tools with those of the non-coated tools and to find out the optimal cutting condition of the TiN coated tool. The coated tools were prepared by the sputtering process at $4$\times$10^{-3}$Torr. When the cutting speed is increased 22.2% from 90m/min, the limited life of coating bite was decreased by 60.61%, but non-coating bite was decreased by 64.05%. In the tool lifetime equation of the coated tools "a"(exponent of feed rate) was not much changed in comparison with that of the non-coated tools but "n" (exponent of tool′s life) was increased by 9.3% and "b" (exponent of cutting depth) was increased by 2.4%. It was thought to be that TiN coated tools was used for higher cutting speed than non-coated tools to improve the lifetime of the coated tools.

• Bulletin of the Korean Chemical Society
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• 제22권1호
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• pp.19-24
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• 2001

A solvent sublation has been studied for the determination of trace Au(III), Pt(IV) and Pd(II) in waste water with their complexes of 2-mercaptobenzothiazole (MBT). Experimental conditions such as the concentration of HCl, the amount of MBT as a ligand, the type and amount of surfactants, bubbling rate and time, and the type of organic solvent were optimized for the solvent sublation, i.e., 25.0 mL of 2.0 M HCl solution and 30mL of 0.4%(w/v) MBT ethanolic solution were added to a 1.0 L sample to form stable complexes. The addition of 4.0 mL of 1 ${\times}$$10^{-3}$ M CTAB (cetyltrimehtylammonium bromide) solution was needed for the effective flotation accomplished by bubbling nitrogen gas at the rate of 40.0 mL/min for 35 minutes. As a solvent, 20.0 mL of MIBK (methylisobuthylketone) was used to extract the floated complexes. The procedure was applied to three kinds of waste waters. Au(III) was determined as 0.68 ng/mL and 0.98 ng/mL respectively for final washed water of two plating industries in Banwol. Pd(II) and Pt(IV) were not detected in any of the three samples. The recovery, which was obtained with analyte-spiked samples, were 95-120%.

• 한국자기학회지
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• 제17권3호
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• pp.133-136
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• 2007

퍼말로이 도금용 순수전해액에 유기첨가제(organic additive)를 첨가하여 제작된 박막의 물성과 자성의 변화를 조사하였다. 일정한 도금조건에서 특정한 유기첨가제를 첨가하여 도금한 퍼말로이 박막은 순수한 전해액으로만 제작된 박막과는 결정성과 표면 거칠기가 달라진다. 그 결과로 도금 박막의 보자력 등 자기적 특성이 변화하였다. 유기첨가제에 의한 이러한 특성 변화는 자기임피던스 비율을 최대 20%까지 증가시키는 역할을 하였다.

• 마이크로전자및패키징학회지
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• 제19권4호
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• pp.65-69
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• 2012

복합도금이란 금속 도금층을 매트릭스로 세라믹, 폴리머, 나노분말과 같은 입자를 공석시켜 경도의 향상, 내마모성, 내식성, 자기 윤활성 등의 특성을 갖는 복합 금속피막을 얻어내는 방법으로 본 연구에서는 나노입자로 $TiO_2$를 사용하여 니켈과 함께 복합도금층을 형성하였다. $TiO_2$를 첨가시킨 복합전기도금을 통해 표면저항성 향상, 광분해 효과를 기대할 수 있다. 용액조건 중 pH 변화에 따른 zeta전위를 측정하였다. 초음파처리를 통한 물리적인 방법으로 용액 중 나노분말의 응집을 최소화한 후 $TiO_2$-Ni 복합도금을 실시하였다. 최적의 도금 조건으로 $50^{\circ}C$에서 pH 3.5, 전류밀도 $40mA/cm^2$에서 가장 효과적이었으며 Ti의 함량은 $50^{\circ}C$에서 15-20 at.%로 확인되었다.

• 한국표면공학회지
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• 제48권3호
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• pp.73-81
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• 2015

Chloride plating solution was fabricated by dissolving metal Ni powders in solution with HCl and deionized water. Effects of deposition conditions on the properties of Ni films electrodeposited from chloride baths were studied. Current efficiency of Ni films electrodeposited from the baths containing saccharin was decreased with increasing the current density. Residual stress of Ni thin films ware measured to be about 230 ~ 435 MPa in the range of current density of $10{\sim}25mA/cm^2$. Cathode current efficiency in baths without saccharin was initially increased with increasing pH, while it was decreased with increasing pH further. Cathode current efficiency in baths with saccharin (except at pH 2) exhibited less 10 ~ 20% than that in baths without saccharin. Residual stress of Ni films electrodeposited from baths without saccharin was measured to be 388 ~ 473 MPa in the range of pH 2 ~ pH 5 and then was increased to 551 MPa at pH 6. On the other hand, residual stress of Ni films electrodeposited from baths with saccharin was increased with increasing pH. Surface morphology was strongly affected by the change of current density, but slightly by solution pH and addition of saccharin.

• 한국발생생물학회지:발생과생식
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• 제12권1호
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• pp.51-56
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• 2008

제브라피쉬 배아 유래세포의 최적 성장조건을 확립하기 위해 3종류의 배지 DMEM, K-NAC, D-NAC 그룹에서의 세포 성장률을 비교하였다. 실험 결과, 접종밀도에 따른 성장률의 경우, DMEM에 비해 K-NAC 그룹에서 초기 접종 효율이 높게 나타났으며, 후기 성장률은 DMEM 그룹에서 높게 나타났다. K-NAC, DMEM 그룹 모두 FBS 농도에 의한 성장차는 보이지 않았으며, 0.1% embryo extract를 첨가한 배지에서 효과는 낮게 나타났으나 1% trout serum 첨가한 경우 매우 높은 성장률을 보였다(p<0.05). $2-3{\times}10^5$ 밀도로 접종한 그룹에서는 유의차가 없었으나, $4{\sim}5{\times}10^5$ 밀도에서는 DMEM 그룹이 K-NAC 그룹보다 다소 높은 성장률을 보였다(p<0.1). DMEM과 D-NAC 그룹에서의 FBS 농도에 따른 성장률을 비교한 결과, FBS 농도에 따른 성장차는 유의하지 않았으나(p<0.05), D-NAC의 모든 실험군이 DMEM 그룹에 비해 높은 성장률을 보였다(p<0.05).

• Journal of Plant Biotechnology
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• 제35권1호
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• pp.81-86
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• 2008

감귤에 있어서 원형질체 융합에 의한 체세포잡종체 생산을 위해서는 우선 캘러스 원형질체로부터의 식물체 재분화가 가능하여야 하기 때문에 온주밀감의 캘러스 원형질체로 부터 배형성과정을 통한 식물체 재분화에 관한 실험을 수행하였다. 흥진조생의 어린 미성숙 배주의 주심조직으로부터 유기된 배형성 캘러스를 사용하여 건강한 원형질체를 분리하고 0.6 M $BH_3$ 배지를 배양배지로 사용하여 배양방법에 따른 plating efficiency를 비교해 본 결과 liquid over solid 배양시 원형질체로부터의 미소괴 형성율이 더 높음을 알 수 있었으며, 적정 배형성 배지 선발에서는 1500 mg/L malt extract 첨가 배지에서 배형성율이 높았다. 자엽형 배로부터의 신초유기를 위한 배지비교에서는 1.0 mg/L GAB 첨가배지에서 발근과 함께 정상적으로 재분화된 신초를 얻을 수 있었다. 원형질체 배양으로부터 재분화된 식물체들은 순화과정을 거쳐 온실 육묘중에 있으며, 생장상이나 형태적인 특성에 있어서 모본 식물체와 차이가 없음을 확인할 수 있었다. 본 실험으로 얻어진 원형질체 배양에 의한 식물체 재분화 체계를 바탕으로 이종속간 감귤의 원형질체 융합 기술을 이용하여 교배육종이 불가능한 품종들로부터 우수한 형질을 지닌 감귤 품종 및 대목용 품종 생산에 활용하고자 한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.229-229
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• 2010

With the scaling down of ultra large integrated circuits (ULSI) to the sub-50 nm technology node, the need for an ultra-thin, continuous and conformal diffusion barrier and Cu seed layer is increasing. However, diffusion barrier and Cu seed layer formation with a physical vapor deposition (PVD) method has become difficult as the technology node is reduced to 30 nm and beyond. Recent work on self-forming barrier processes using PVD Cu alloys have attracted great attention due to the capability of conformal ultra-thin barrier formation using a simple technique. However, as in the case of the conventional barrier and Cu seed layer, PVD of the Cu alloy seed layer will eventually encounter the difficulty in conformal deposition in narrow line trenches and via holes. Atomic layer deposition (ALD) has been known for its good step coverage and precise thickness control, and is a candidate technique for the formation of a thin conformal barrier layer and Cu seed layer. Conformal Cu-Mn seed layers were deposited by plasma enhanced atomic layer deposition (PEALD) at low temperature ($120^{\circ}C$), and the Mn content in the Cu-Mn alloys were controlled form 0 to approximately 10 atomic percent with various Mn precursor feeding times. Resistivity of the Cu-Mn alloy films decreased by annealing due to out-diffusion of Mn atoms. Out-diffused Mn atoms were segregated to the surface of the film and interface between a Cu-Mn alloy and $SiO_2$, resulting in self-formed $MnO_x$ and $MnSi_xO_y$, respectively. No inter-diffusion was observed between Cu and $SiO_2$ after annealing at $500^{\circ}C$ for 12 h, indicating an excellent diffusion barrier property of the $MnSi_xO_y$. The adhesion between Cu and $SiO_2$ was enhanced by the formation of $MnSi_xO_y$. Continuous and conductive Cu-Mn seed layers were deposited with PEALD into 32 nm $SiO_2$ trench, enabling a low temperature process, and the trench was perfectly filled using electrochemical plating (ECD) under conventional conditions. Thus, it is the resultant self-forming barrier process with PEALD Cu-Mn alloy film as a seed layer for plating Cu that has further potential to meet the requirement of the smaller than 30 nm node.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2000년도 추계학술발표회 초록집
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• pp.3-4
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• 2000

Many researchers are interested in the synthesis and characterization of carbon nitride and diamond-like carbon (DLq because they show excellent mechanical properties such as low friction and high wear resistance and excellent electrical properties such as controllable electical resistivity and good field electron emission. We have deposited amorphous carbon nitride (a-C:N) thin films and DLC thin films by shielded arc ion plating (SAIP) and evaluated the structural and tribological properties. The application of appropriate negative bias on substrates is effective to increase the film hardness and wear resistance. This paper reports on the deposition and tribological OLC films in relation to the substrate bias voltage (Vs). films are compared with those of the OLC films. A high purity sintered graphite target was mounted on a cathode as a carbon source. Nitrogen or argon was introduced into a deposition chamber through each mass flow controller. After the initiation of an arc plasma at 60 A and 1 Pa, the target surface was heated and evaporated by the plasma. Carbon atoms and clusters evaporated from the target were ionized partially and reacted with activated nitrogen species, and a carbon nitride film was deposited onto a Si (100) substrate when we used nitrogen as a reactant gas. The surface of the growing film also reacted with activated nitrogen species. Carbon macropartic1es (0.1 -100 maicro-m) evaporated from the target at the same time were not ionized and did not react fully with nitrogen species. These macroparticles interfered with the formation of the carbon nitride film. Therefore we set a shielding plate made of stainless steel between the target and the substrate to trap the macropartic1es. This shielding method is very effective to prepare smooth a-CN films. We, therefore, call this method "shielded arc ion plating (SAIP)". For the deposition of DLC films we used argon instead of nitrogen. Films of about 150 nm in thickness were deposited onto Si substrates. Their structures, chemical compositions and chemical bonding states were analyzed by using X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and infrared spectroscopy. Hardness of the films was measured with a nanointender interfaced with an atomic force microscope (AFM). A Berkovich-type diamond tip whose radius was less than 100 nm was used for the measurement. A force-displacement curve of each film was measured at a peak load force of 250 maicro-N. Load, hold and unload times for each indentation were 2.5, 0 and 2.5 s, respectively. Hardness of each film was determined from five force-displacement curves. Wear resistance of the films was analyzed as follows. First, each film surface was scanned with the diamond tip at a constant load force of 20 maicro-N. The tip scanning was repeated 30 times in a 1 urn-square region with 512 lines at a scanning rate of 2 um/ s. After this tip-scanning, the film surface was observed in the AFM mode at a constant force of 5 maicro-N with the same Berkovich-type tip. The hardness of a-CN films was less dependent on Vs. The hardness of the film deposited at Vs=O V in a nitrogen plasma was about 10 GPa and almost similar to that of Si. It slightly increased to 12 - 15 GPa when a bias voltage of -100 - -500 V was applied to the substrate with showing its maximum at Vs=-300 V. The film deposited at Vs=O V was least wear resistant which was consistent with its lowest hardness. The biased films became more wear resistant. Particularly the film deposited at Vs=-300 V showed remarkable wear resistance. Its wear depth was too shallow to be measured with AFM. On the other hand, the DLC film, deposited at Vs=-l00 V in an argon plasma, whose hardness was 35 GPa was obviously worn under the same wear test conditions. The a-C:N films show higher wear resistance than DLC films and are useful for wear resistant coatings on various mechanical and electronic parts.nic parts.

• 식물조직배양학회지
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• 제22권1호
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• pp.7-11
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• 1995

종자발아 후 5일된 양배추 그린챌린져 배축으로부터 분리된 원형질체로부터 완전한 식물체를 재분화 시켰다. Kao배지와 B5 배지를 기본으로 한 기존의 몇가지 배지에서 원형질체를 배양한 결과 변형시킨 BS배지에서 Plating efficiency는 낮았으나 식물체 재분화율은 가장 높게 나타나 거의 원형질체 배양배지 조성, 생장조절제 농도 등이 재분화에 상당한 영향을 주는 것으로 나타났다. 또한 사용된25가지 종류의 재분화 배지중에서 MS배지에 l% sucrose zeatin 3 mg/L, 1.6% T.C. agar가 첨가된 배지에서 재분화율이 가장 좋았다. 식물체 재분화에 미치는 PVP (polyvinyl Polypyrrolidone)와 agar 농도의 영향으로는 PVP는 큰 효과가 없었고 agar농도를 1.6%로 2배 증가시켰을 때 재분화율이 다소 높아졌다. 현재까지 재분화된 식물체는 150여 개체로서 포장에서 재배중에 있다.