• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.1
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• pp.97-103
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• 2000

This paper deals with residual stresses induced at the viscoelastic adhesive layer between the semiconductor chip and the leadframe during adhesion process. The adhesive layer has been assumed to be“thermorheologically simple”. The time-domain boundary element method(BEM) has been employed to investigate the behavior of interface stresses. Numerical results show that very large stress gradients are present at the interface corner and such singularity might lead to local yielding or edge delamination.

• Journal of Periodontal and Implant Science
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• v.28 no.2
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• pp.371-376
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• 1998

This study presents an evaluation of the effectiveness of nonsurgical subgingival scaling and root planing related to initial pocket depth, type of teeth, and individual root surfaces. A total of 110 teeth designated for periodontal surgery in 67 patients with marginal periodontitis were selected and received thorough scaling and root planing with standard rigid Gracey curettes. After a healing period of 4 to 8 weeks, residual calculus was assessed at the time of periodontal surgery following the reflection of mucoperiosteal flap. The results demonstrated a high correlation between the percentage of residual calculus and initial pocket depth. It was further noted that tooth type and involved root surface also influenced the rate of calculus remnant. The results of this study suggest that complete removal of subgingival calculus utilizing conventional instrumentation via closed approach is rare.

• Journal of Ocean Engineering and Technology
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• v.15 no.2
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• pp.130-134
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• 2001

Recently environmental pollution at sea becomes serious, so every governmental organization makes its effort to solve this problem. Combustible ocean wastes as of ropes, fishing nets, and tires are usually highly polymerized compound materials. The problem of ocean waste treatment can be solved by using the pyrolysis method. Pyrolysis characteristics of ocean waste was examined to get the basic data for the production system of fuel from the ocean waste. Thermogravimetric experiment showed that residual mass rate decreases as the velocity of temperature-rising becomes lower. The pyrolysis of waste rope and fishing net occurs at 300~450$^{\circ}C $ and the waste tire does at 350~450$^{\circ}C $. Pyrolysis time is estimated about 15 to 20 minutes in the temperature range when lively act of pyrolysis temperature reached.

• Journal of the Korean Society of Safety
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• v.14 no.1
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• pp.49-54
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• 1999

In this paper. we studied cut off characteristics and fire hazard of residual current protective devices(RCD or ELB) for low voltage. The operative time of RCD with grounding resistance was analyzed by using RCD operating tester. The surface structure and composition of insulator were analyzed by using scanning electron microscope(SEM) and energy dispersive x-ray spectroscopy(EDX). The surface of phenol resin showed network structure and void. The spectra shown in EDX analysis are composed not only of the corresponding elements but also of several new spectra, as CK. OK$\alpha$. MgK, SiK. and CaK, which were absent in original material.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.101-103
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• 2009

Minimizing the residual impurity level on the MgO layer is the key factor for reducing temporal dark image sticking on bright screen. In this paper, to reduce the residual impurity level on the MgO layer of 50-in. full-HD ac-PDP with He (35%) - Xe (11%) contents, RF-plasma treatments on the MgO layer are adopted under various gases for plasma treatment. As a result of monitoring the difference in the display luminance between the before and after 5-min. sustain discharge with a square-type image at peak luminance, the Ar and Ar>$O_2$ plasma treatments can reduce the temporal dark image sticking on the bright screen in an ac-PDP.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.5
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• pp.1-10
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• 2008

Residual stress caused in the weldments with high restraint force are often during welding observed in the weldments of large size nozzles or radial tanks. The reason is that quantitative analysis about thermal stresses during welding is lack for this weldments. To verify Finite Elements Method(FEM) theory, the temperature was measured with thermocouple in a real time in this paper. Also analysis of the thermal stress for welding condition is performed by ABAQUS program package on various welding condition in 304 stainless steel butt welding.

• Journal of Environmental Health Sciences
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• v.31 no.2 s.83
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• pp.147-151
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• 2005

The disinfection effect of free residual chlorine and monochloramine on biofilm communities were investigated by CLPP (community level physiology profile) using Biolog GN plates. Low concentration of disinfectant, $0.5\;mg/\iota$ free chlorine and $1.0\;mg/\iota$ monochloramine, stimulated the growth of bacteria rather than disinfection. Bacterial concentrations were decreased at more than $1.0\;mg/\iota$ of disinfectants. CLPP was different with the type and concentration of disinfectant and sampling time. Common and different carbon sources were actively used with similar bacterial concentration in free chlorine and monochloramine. This represents the differences of bacterial communities with tap water contact times and disinfectant.

• Journal of Mechanical Science and Technology
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• v.20 no.10
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• pp.1646-1652
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• 2006

A model of mechanical behavior of microcantilever due to intrinsic strain during deposition of MEMS structures is derived. A linear ordinary differential equation is derived for the beam deflection as a function of the thickness of the deposited layer. Closed-form solutions are not possible, but numerical solutions are plotted for various dimensionless ratios of the beam stiffness, the intrinsic strain, and the elastic moduli of the substrate and deposited layer. This model predicts the deflection of the cantilever as a function of the deposited layer thickness and the residual stress distribution during deposition. The usefulness of these equations is that they are indicative of the real time behavior of the structures, i.e. it predicts the deflection of the beam continuously during deposition process.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.2
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• pp.55-61
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• 2002

In this paper, 'lifetime-temperature rise model' based on the 'lifetime-resistance model' is theoretically Proposed, in order to find out the evaluation method of degradation and the residual lifetime by use of infrared image camera for electric connections/contacts. Two assumptions have been builded up for the 'lifetime-temperature rise model': one is associated with the linear relationship between the temperature ism ΔK and contact resistance, and the other the functional relationship between the temperature of electric connections/contacts and the operating time presenting in the 'lifetime-resistance model'. To prove the proposed model, experiments have been performed for various electric connections/contacts. From the experimental results, measured values were quite similar to the calculated values, which proved the above-mentioned two assumptions. Therefore, by use of 'lifetime-temperature rise model', it is possible to estimate the trend of degradation and the residual lifetime for electric connections/contacts through the temperature measurements .

• Journal of Sensor Science and Technology
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• v.14 no.5
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• pp.357-361
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• 2005

Low-stress silicon nitride (LSN) thin films with embedded metal line have been developed as free standing structures to keep microspheres in proper locations and localized heat source for application to a chip-based sensor array for the simultaneous and near-real-time detection of multiple analytes in solution. The LSN film has been utilized as a structural material as well as a hard mask layer for wet anisotropic etching of silicon. The LSN was deposited by LPCVD (Low Pressure Chemical Vapor Deposition) process by varing the ratio of source gas flows. The residual stress of the LSN film was measured by laser curvature method. The residual stress of the LSN film is 6 times lower than that of the stoichiometric silicon nitride film. The test results showed that not only the LSN film but also the stack of LSN layers with embedded metal line could stand without notable deflection.