• 한국레이저가공학회지
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• 제2권2호
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• pp.34-41
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• 1999

A RS840 $CO_2$laser and a powder auto-feeding apparatus have been used to deposit single tracks of Ni-base superalloy on low carbon steel. In this paper, the effects of laser cladding parameters on clad geometry, dilution and microhardness are studied. As a results, the w/h ratio of the clad layer increases with decreasing powder feed rate and increasing laser scan speed. Increase of powder density and decrease of specific energy have little effect on dilution. It was found that the clad layer of the highest hardness has a structure in which fine and leaf like phases are dispersed in ${\gamma}$Ni matrix.

• 센서학회지
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• 제21권5호
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• pp.319-323
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• 2012

In this paper, we present the possibility of quantification analysis for $A{\beta}$ captured by micro beads using Near-filed detection. In order to evaluate detection efficiency, detected signals were compared with different sizes of micro beads and a varied number of micro beads. Also, $A{\beta}$ deposits and $A{\beta}$ binding to micro beads were measured, therefore, we observed the $A{\beta}$ deposit and light scattering around the surface of micro beads induced by attached $A{\beta}$. This method can be used for quantitative analysis for not only the number of $A{\beta}$, but also the binding ratio of $A{\beta}$ to micro beads.

• Corrosion Science and Technology
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• 제9권4호
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• pp.171-174
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• 2010

MAO (micro-arc oxidation) is an eco-friendly convenient and effective technology to deposit high-quality oxide coatings on the surfaces of Ti, Al, Mg and their alloys. The roles of the electrolyte concentration and relative cathode electrode area sizes in the grown oxide film during titanium MAO were investigated. The higher the concentration of the electrolyte, the lower the $R_{total}A$ value. The oxide film produced by the lower concentration of the electrolyte is thinner and less uniform than the film by the higher concentration, which is thick and porous. The cathode area size must be bigger than the anode area size in order to minimize the voltage drop across the cathode. The ratio of the cathode area size to the anode area size must be bigger than 8. Otherwise, the cathode will be another source for voltage drop, which is detrimental to and slows down the oxide growth.

• 한국광물학회지
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• 제11권2호
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• pp.69-84
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• 1998

The Daehyun sericite deposit in socheon-myun, Bongwha-gun, Kyungsangbuk-do, Korea, has been formed by the hydrothermal alteration of the Hongjesa granite of Precambrian age, leaving the muscovite granite between ore body and the Hongjesa granite as the wall rock alteration zone. The process of sericitization of granitic rock as well as chemistry and structures of sericites were studied using polarizing microscope, X-ray diffractometer (XRD), electron probe microanalyzer (EPMA) and high resolution transmission electron microscope (HRTEM). There are two genetic types of sericites having different chemistry and structure. The early sericite is of 2M1 polytype and has octahedral composition close to muscovite. It has been formed from the primary muscovite, tourmaline and quartz under a relatively high temperature. The late sericite is of 1M, 2M1 and 3T polytypes and has phengitic composition. It has been formed form feldspar, biotite, muscovite and tourmaline under a relatively low temperature. Chemical analyses show t, the early sericite has less Mg+FeT content and lower Si/AlIV ratio in tetrahedral site than the late sericite.

• Journal of Magnetics
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• 제12권3호
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• pp.124-128
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• 2007

Co/Cu GMR multilayers were electrodeposited from various electrolytes using the dual bath technique to achieve high sensitive GMR multilayers. GMR ratio and sensitivity were strongly influenced by solution compositions and electrodeposition parameters where GMR and sensitivity of 12% and 0.052%/Oe were achieved from pyrophosphate baths. The effect of plating conditions on properties of Co/Cu multilayers may be attributed to crystallinity and grain size of deposits, and the ability of plating solutions to deposit contiguous films at lower nano thicknesses.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1998년도 PROCEEDINGS OF THE 15TH KACG TECHNICAL MEETING-PACIFIC RIM 3 SATELLITE SYMPOSIUM SESSION 4, HOTEL HYUNDAI, KYONGJU, SEPTEMBER 20-23, 1998
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• pp.1-20
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• 1998

Processing of thin films by chemical vapor deposition (CVD) is accompanied by chemical reactions, in which the rigorous kinetic analysis is difficult to achieve. In these conditions, thermodynamic calculation leads to better understanding of the CVD process and helps to optimise the experimental parameters to obtain a desired product. A CVD phase diagram has been used as guide lines for the process. By determining the effect of each process variable on the driving force for deposition, the thermodynamic limit for the substrate temperature that diamond can deposit is calculated in the C-H system by assuming that the limit is defined by the CVD diamond phase diagram. The addition of iso-supersaturation ratio lines to the CVD phase diagram in the Si-Cl-H system provides additional information about the effects of CVD process variables.

• 한국안전학회지
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• 제17권4호
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• pp.153-159
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• 2002

This experimental study is aimed to increasing the velocity in the sewerage and also development of easy removal method for a corrosion and sand in the flow pipe. And the result by the increasing the out flow per unit time, diameter of sewerage pipe is becoming small size, cut down the construction fee and the same time reducing the tubulent flow pattern in the flow pipe. As a result of detected experimental velocity signal from the probe in the test wall surface, reducing the pump power and increasing the out flow unit time. Apparent water velocity decreases as the value of void ratio increases depends on the varies center of pipe.

• 한국표면공학회지
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• 제29권5호
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• pp.330-337
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• 1996

A rf reactive sputter deposition technique was adopted to deposit ferroelectric lead zirconate titanate (PZT) thin films with high rate from a ZrTi alloy target combined with PbO pellets. Deposition characterisitics including the effects of PbO are ratio were discussed. A new deposition mode called the quasi-metallic mode was observed. Perovskite PZT films were prepared at a growth temperature as low as$ 450^{\circ}C$. However, because the target structure is unstable, weproposed a mixture target consisted of Zr, Ti and PbO. Fundamental experiments were investigated using the powder target. Perovskite PZT film could be obtained at $450^{\circ}C$ with better electrical properties also.

• 한국레이저가공학회지
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• 제5권2호
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• pp.17-22
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• 2002

Characteristics of micro carbon structures fabricated with laser-induced chemical vapor deposition (LCVD) are investigated. An argon ion laser (λ＝514.5nm) and ethylene gas were utilized as the energy source and precursor, respectively. The laser beam was focused onto a graphite substrate to produce carbon deposit through thermal decomposition of the precursor. Average growth rate of a carbon rod increased for increasing laser power and pressure. Micro carbon rods with good surface quality were obtained at near the threshold condition. Micro carbon rods with aspect ratio of about 100 and micro tubular structures were fabricated to demonstrate the possible application of this method to the fabrication of three-dimensional microstructures. Laser Raman spectroscopic analysis of the micro carbon structures revealed that the carbon rods are consisting of amorphous carbon.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.30-31
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• 2006

We have fabricated SmBCO coated conductor on IBAD-MgO substrates using unique co-evaporation method. The batch type co-deposition system was specially designed and named as EDDC(evaporation using drum m dual chamber) that is possible to deposit superconducting layer with different composition ratio at low temperature of $700^{\circ}C$. In this study, we have investigated the influence of SmBCO phase composition and texture of IBAD-MgO template on the critical current density. We have changed the deposition rates of Sm, Ba and Cu during co-evaporation to examine the optimal composition ratio shown better critical current density. The composition ratio and surface morphology of SmBCO coated conductors were analyzed by the EDX and SEM, respectively. A higher critical current density was measured at superconducting phase composition ratio of Ba deficiency, Sm or Cu rich compared to the Sm1Ba2Cu3Ox stoichiometry.