• Journal of the Korea Concrete Institute
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• v.18 no.1 s.91
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• pp.125-132
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• 2006

Recently, surface finishing and protection materials were developed to restore performance of the deteriorated concrete and inhibiting corrosion of the reinforcing-bar. For this purpose, surface protection agent as well as coatings are used. Coatings have the advantage of low Permeability of $CO_2,\;SO_2$ and water. However, for coatings such as epoxy, urethane and acryl, long-term adhesive strength is reduced and the formed membrane of those is blistered by various causes. Also when organic coatings are applied to the wet surface of concrete, those have a problem with adhesion. On the other hand, surface protection agent penetrates into pore structure in concrete through capillary and cm make a dense micro structure in concrete as a result of filling effect. Furthermore, the chemical reaction between silicate from surface protection agent and cement hydrates can also make a additional hydration product which is ideally compatible with concrete body. The aim of this study is to examine the effect of penetrative surface protection agent(SPA) by evaluating several concrete durability characteristics. The results show that the concrete penetrated surface protection agent exhibited higher durability characteristics for instance, carbonation velocity coefficient, resistance to chemical attack and chloride ion penetration than the plain concrete. These results due to formation of a discontinuous macro-pore system which inhibits deterioration factors of concrete by changed the pore structure(porosity and pore size distributions) of the concrete penetrated surface protection agent.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.6
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• pp.972-980
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• 2004

Cathodic protection is being widely used to protect steel structures in sea water environment, In order to protect steel structures completely, the flow condition of sea water surrounding with this structures and the surface condition of the structures must be considered for a desirable design of cathodic protection. In this study, the optimum protection potential and current density were investigated in terms of cathodic current density, surface condition and a flow condition of sea water. The optium protection potential of the cleaned specimen was -770 mV(SCE) and below. However in the case of the rusted specimen, its potential was -700 mV(SCE) and below, which was somewhat positive than the cleaned one irrespective of flow condition. The optimum cathodic protection current density for both the cleaned and rusted specimens was 100 mA/$\textrm{m}^2$, however, on the flow condition, 200 mA/$\textrm{m}^2$ to be supplied for cathodic protection of steel structures completely for both cleaned and rusted specimens.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.251-251
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• 2009

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.4
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• pp.470-480
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• 2016

The reversal of a silicon chip to find out its security structure is common and possible at the present time. Thanks to reversing, it is possible to use a probing attack to obtain useful information such as personal information or a cryptographic key. For this reason, security-related blocks such as DES (Data Encryption Standard), AES (Advanced Encryption Standard), and RSA (Rivest Shamir Adleman) engines should be located in the lower layer of the chip to guard against a probing attack; in this regard, the addition of a silicon-surface-protection layer onto the chip surface is a crucial protective measure. But, for manufacturers, the implementation of an additional silicon layer is burdensome, because the addition of just one layer to a chip significantly increases the overall production cost; furthermore, the chip size is increased due to the bulk of the secure logic part and routing area of the silicon protection layer. To resolve this issue, this paper proposes a practical silicon-surface-protection method using a metal layer that increases the security level of the chip while minimizing its size and cost. The proposed method uses a shift register for the alternation and variation of the metal-layer data, and the inter-connection area is removed to minimize the size and cost of the chip in a more extensive manner than related methods.

• Journal of the Korean institute of surface engineering
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• v.36 no.1
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• pp.9-13
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• 2003

Plasma polymerized organic thin films were deposited on Si(100), glass and metal substrates at $25∼100 ^{\circ}C$ using thiophene and toluene precursors by PECVD method. In order to compare physical and electrochemical properties of the as-grown thin films, the effects of the RF plasma power in the range of 30∼100 W and deposition temperature on both corrosion protection efficiency and physical properties were studied. We found that the corrosion protection efficiency ($P_{k}$), which is one of the important factors for corrosion protection in the interlayer dielectrics of microelectronic devices application, was increased with increasing RF power. The highest $P_{k}$ value of plasma polymerized toluene film (85.27% at 70 W) was higher than that of the plasma polymerized thiophene film (65.17% at 100 W), indicating inhibition of oxygen reduction. The densely packed and tightly interconnected toluene film could act as an efficient barrier layer to the diffusion of molecular oxygen. The result of contact angle measurement showed that the plasma polymerized toluene films have more hydrophobic surface than those of the plasma polymerized thiophene films.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.4
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• pp.78-85
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• 2010

When the fire occur, concrete filled steel tube(CFT) columns expected to form a much distinction in a fire resistance performance according to a kind of fire protection because the steel surface is directly exposed to high temperature. In this study, an experiment by three factors which were kind of fire protection, thickness of protection and time was performed to get the characteristics of temperature distribution types of CFT column with fire protection. As the result of this study, on a basis of heating temperature, spray protection was the most superior in a fire resistance performance, fireproof paint was next, and without fire protection was most inferior. In a heating time-location relationship, the temperature increased slowly on the surface of the concrete, but the temperature increased sharply on the surface of the steel.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.93-96
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• 2005

Concrete has been considered as a semi-permanent structural material, because its excellent durability. Recently, durability decline of concrete construction by environmental pollution is becoming social problem. The durability of high durable structure is declined by carbonate, chloride permeation and deterioration of waterproof performance, etc. This study of penetrating surface protection materials evaluated about carbonation, chloride permeation, waterproof performance, and durability of abrasion, etc. It is profitable in durability that spread penetrating surface protection materials

• Journal of the Korean institute of surface engineering
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• v.44 no.3
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• pp.105-116
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• 2011

Ships and offshore structures are exposed to harsh marine environments, and maintenance and repair are becoming increasingly important to the industry and the economy. The major corrosion phenomenons of metals and alloys in marine environment are pitting corrosion, stress corrosion cracking, crevice corrosion, fatigue corrosion, cavitation-erosion and etc. due to the effect of chloride ions and is quite serious. Methods of protection against corrosion can generally be divided into two groups: anodic protection and cathodic protection. Anodic protection is limited to the passivity characteristics of a material in its environment, while cathodic protection can apply methods such as sacrificial anode cathodic protection and impressed current cathodic protection. Sacrificial anode methods using Al and Zn alloys are widely used for marine structures and vessels intended for use in seawater. Impressed current cathodic protection methods are also widely used in marine environments, but tend to generate problems related to hydrogen embrittlement caused by hydrogen gas generation. Therefore, it is important to the proper maintenance and operation of the various corrosion protection systems for ship in the harsh marine environment.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.12
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• pp.126-134
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• 2003

In order to investigate the effect of surface treatment in Aluminium alloy and Titanium alloy which are used to armor material during ballistic impact, a ballistic testing was conducted. Anodizing was used to achieve higher surface hardness of Aluminium alloy and Iron plating in PVD(Physical Vapor Deposition) method was used to achieve higher surface hardness of Titanium alloy. Surface hardness test were conducted using a Micro victor's hardness tester. Ballistic resistance of these materials was measured by protection ballistic limit(V-50), a statical velocity with 50% probability penetration. Fracture behaviors and ballistic tolerance, described by penetration modes, are respectfully observed from the results of V-50 test and Projectile Through Plates (PTP) test at velocities greater than V-50. PTP tests were conducted with 0$^{\circ}$obliquity at room temperature using 5.56mm ball projectile. V-50 tests were conducted with 0$^{\circ}$obliquity at room temperature with projectiles that were able to achieve near or complete penetration during PTP tests. Surface hardness, resistance to penetration. and penetration modes of surface treated alloy laminates are compared to those of surface non-treated alloy laminates. A high speed photography was used to analyze the dynamic perforation phenomena of the test materials.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1483-1490
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• 2011

The protection effect of a $ZrO_2$ coating layer on a $LiCoO_2$ thin film was characterized. A wide and smooth $LiCoO_2$ thin film offers sufficient opportunity for careful observation of the reaction at the interface between cathode (coated and uncoated) and electrolyte. The formation of a $ZrO_2$ coating on a $LiCoO_2$ thin film was confirmed by secondary ion mass spectrometry. Scanning electron and atomic force microscopy were used to characterize the surface morphologies of coated and uncoated films before and after cycling. A $ZrO_2$-coated $LiCoO_2$ film showed a higher discharge capacity and rate capability than an uncoated film. This may be associated with a surface protection effect of the coating. The surface of a pristine film was damaged during cycling, whereas the coated film maintained a relatively clear surface under the same measurement conditions. This result clearly demonstrates the protection effect of a $ZrO_2$ coating on a $LiCoO_2$ thin film.