• International Journal of Advanced Culture Technology
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• v.3 no.1
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• pp.39-45
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• 2015

This research aims to study an effect of sodium chloride solution concentration on the corrosion rate of AA1100 aluminium alloy and SGACD zinc coated steel lap joint with a test duration of 30 days and a test temperature of $45^{\circ}$. The summarized results are as follows. Increase of the NaCl solution concentration increased the weight loss of Al, corrosion rate of Al, weight loss of Fe and also decreased the corrosion rate of Fe. Increase of the test duration affected to increase the weight loss and corrosion rate of Al and also decrease the weight loss and corrosion rate of Fe. The corrosion that was formed in a lap joint consisted of the uniform corrosion on the surface of the metals and the galvanic corrosion in the lap area of the joint. The maximum weight loss of AA 1100 aluminium and SGACD zinc coated steel that was occurred in the sodium chloride with 3.25% was 2.203% and 3.208%, respectively.. The maximum corrosion rate of AA 1100 aluminium and SGACD zinc coated steel that was occurred in 4.00% and 3.5% sodium chloride solution was 0.156 mm/year and 0.479 mm/year, respectively.

• Journal of KSNVE
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• v.10 no.4
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• pp.662-668
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• 2000

Sound transmission characteristics are investigated on the aluminium extruded panels used for railway vehicles. An equivalent orthotropic plate model and mass law are applied to predict the sound transmission loss. An extruded panel specimen used in the floor of railway vehicles is manufactured and is tested to measure sound transmission loss by two reverberant chamber method. Predicted transmission loss I compared with measured values and the effect of local resonance on the transmission characteristics is identified. The results are applied to design the extruded panel having better sound insulation performance.

• Journal of the Korean Wood Science and Technology
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• v.12 no.2
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• pp.10-19
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• 1984

The $3{\times}3{\times}30$ ($cm^3$) sized lumbers of Populus alba-grandulosa L. were treated with four fire-retardant solutions of ammonium sulfate, monoammonium phosphate, diammonium phosphate and aluminium chloride for 1, 15, 30, and 60 minutes and 1, 3, and 7 days. Thereafter they were air-dried and burned at high temperature about $1,800^{\circ}C$ and for short time of five minutes. This study estimated the relationship between absorbed chemical amounts and rate of weight loss or residual bending strength of these burned lumbers. The results were as follows: 1) In absorption amount of fire-retardant chemicals, diammonium phosphate showed the largest, aluminium chloride the smallest, but monoammonium phosphate and ammonium sulfate showed similar level. 2) The absorption amount of chemicals was decreased with the increase of specific gravity in the same species except aluminium chloride. 3) The rate of weight loss was decreased as the absorption amount of chemicals increased, especially monoammonium phosphate was most effective. 4) The MOR value of the residual bending strength was increased as the absorption amount of chemicals increased and especially monoammonium phosphate showed the most efficient effect. 5) Aluminium chloride showed more striking increase of MOR value of residual bending strength with the increase of absorption amount than any other chemical, therefore its MOR value was similar to the maximum MOR value of the most effective monoammonium phosphate. 6) The correlation between weight loss and MOR value of the residual bending strength was negative and aluminium chloride showed the most striking negative relation, but the others showed similar trends. 7) The correlation between work to proportional limit and absorption amount of chemicals was positive and the degree of increase in work to proportional limit was most in aluminium chloride, and the next, in monoammonium phosphate and diammonium phosphate in turn. 8) The correlation between work to maximum load and absorption amount of chemicals showed positive and diammonium phosphate revealed the best result and aluminium chloride showed better results than other two chemicals.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1652-1654
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• 1994

The Extra-high voltage XLPE cable is characterized by low transmission loss, large capacity, and high reliability. Conventionally, for XLPE cables of l54kV and above, aluminium sheath was used to be moisture barrier (thus preventing water tree deterioration of the insulation) and to protect cable core from physical stresses. However, as transmission capacity of the cable increases, so does the cable diameter and the corresponding aluminium sheath outer diameter and thickness. As a result, eddy-current loss in the sheath is increased, limiting the maximum current capacity of the cable itself. As an alternative to aluminium sheath, we have adopted stainless steel sheath with non-magnetic properties and a large resistivity, The new XLPE cable with stainless-steel sheath (CSZV cable) has drastically reduced eddy-current loss in the sheath.

• Journal of Climate Change Research
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• v.2 no.4
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• pp.309-316
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• 2011

The study evaluated the loss rate of carbon dioxide, which is the prevalent greenhouse gas, according to the method of keeping specimens using standard gases. In order to examine the difference generated by a bag of storing specimens, it checked the loss rate according to concentration and time by making a 2nd set of standard gases in a Tedlar bag and an Aluminium bag. The containers lost gases at a rate of 5% or more after 6 day, and 10% or more after 15 days in both bags. In time, it was confirmed that the loss rate of the Aluminium bag was higher than that of the Tedlar bag. Specifically, there was no significant difference between the two bags after 12 days had passed, but by the 15th day, it was confirmed that the loss in an Aluminium bag was more severe than that in the Tedlar bag. The study went on to check the relations between the humidity in storage and the loss rate. The results showed that there was no significant effect of humidity on the loss rate until 72 hours had passed, when the loss rate in the Tedlar bag with high humidity was about 5% higher than that of the Tedlar bag in dry conditions. This study examined the loss rate of carbon dioxide, a typical greenhouse gas. It is important to note that the loss rate was determined by calculating highly reliable carbon dioxide emission and emission coefficient data, with consideration to the method of keeping specimens.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.377-382
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• 2000

Film bulk acoustic resonator (FBAR) using AIN reactively sputtered at room temperature was fabricated. The FBAR is composed of a piezoelectric aluminium nitride thin film, top electrode of Al and bottom electrode of Au connected by a short (200${\mu}{\textrm}{m}$) transmission line on both sides and reflector layers of SiO$_2$- W Pair. The active areas of Al and Au were patterned using 150${\mu}{\textrm}{m}$ diameter shadow mask. The series resonance frequency (fs) and the parallel resonance frequency (fp) were measured at 1.976 GHz and 2.005 GHz, respectively. The minimum insertion loss and return loss were 6.1 dB and 37.19 dB, and the quality factor (Q) was 4261.

• Nuclear Engineering and Technology
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• v.51 no.5
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• pp.1345-1354
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• 2019

Clogging of sump strainers that filter the recirculation water in containment after a loss-of-coolant accident (LOCA) seriously impedes the continued cooling of nuclear reactor cores. In experiments examining the corrosion of aluminium alloy 6061, a common material in containment equipment, in borated solutions simulating the water chemistry of sump water after a LOCA, we found that Fe-bearing intermetallic particles, which were initially buried in the Al matrix, were progressively exposed as corrosion continued. Their cathodic nature $vis-{\grave{a}}-vis$ the Al matrix provoked continuous trenching around them until they were finally released into the test solution. Such particles released from Al alloy components in a reactor containment after a LOCA will be transported to the sump entrance with the recirculation flow and trapped by the debris bed that typically forms on the strainer surface, potentially aggravating strainer clogging. These Fe-bearing intermetallic particles, many of which had a rod or thin strip-like geometry, were identified to be mainly the cubic phase ${\alpha}_c-Al(Fe,Mn)Si$ with an average size of about $2.15{\mu}m$; 11.5 g of particles with a volume of about $3.2cm^3$ would be released with the dissolution of every 1 kg 6061 aluminium alloy.

• Analytical Science and Technology
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• v.13 no.6
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• pp.743-750
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• 2000

For the ${\gamma}$-ray spectrometry analysis of radium and radon in environmental samples, plastic Marinelli beakers have been usually used. But, there are two problems; one is the increment of background by adsorption of airborne radon daughters on the plastic beaker, and other is the incompleteness of radioactive equilibrium by the loss of gaseous radon produced during the radioactive equilibrium process. In order to solve these problems, we made aluminium counting container, and investigated its characteristics. We investigated radioactive equilibrium process using the aluminium container. We found that both solid and liquid samples reached at radioactive equilibrium state in the aluminium container without loss of gaseous radon. By the use of the aluminium container, we established radon and radium analysis method of solid and liquid samples using gamma-ray spectrometry.

• Journal of Korea Foundry Society
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• v.31 no.6
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• pp.336-341
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• 2011

Recently, aluminium usage in the automobile industry has been increased cause of its lightweight. The aluminium has a melting-solidification process in producing line and another melting process was needed in manufacturing process. Two times of melting process for making ingot and casting not only makes the loss of time and money but contaminates the air with Sox, Nox. For this reason, the holding furnace with laminated adiabatic material was developed. This holding furnace can deliver the molten aluminium directly to the industry needing molten aluminium. Recent holding furnace has above $15^{\circ}C/h$ of cooling rate and that causes solidification of molten aluminium. The ANSYS software was used to analysis the heat transfer. The adiabatic materials were laminated with optimized arrangement and holding furnace shape was changed with optimized modelling by ANSYS analysis for reducing the cooling rate of molten aluminium in holding furnace.

• Journal of the Korean Chemical Society
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• v.56 no.2
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• pp.201-206
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• 2012

The anticorrosive effect of 3-Hydroxyflavone (3HF) in combination with quarternary ammonium bromide and iodide salts (QAB and QAI) for aluminium corrosion in NaOH medium was studied at the temperature range of 303K-323K using weight loss study, potentiodynamic polarization study and impedance spectroscopic measurements. The results revealed that the inhibition efficiency increases with the inhibitor concentration and it further increases on the addition of quarternary ammonium bromide and iodide salts. The enhanced inhibition efficiency of the inhibitor in the presence of quarternary ammonium salts may be due to synergistic effect. The adsorption process of 3HF on the aluminium surface obeys Langmuir's adsorption isotherm. The mechanism of adsorption is further supported by Scanning Electron Microscopic study (SEM).