• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.1
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• pp.127-133
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• 2016

This study is performed that furniture and interior materials of MDF's (Medium Density Fiberboard) biodegradation properties, and the goal of this study is investigation of possibility of waste-MDF's composting after landfilling. To investigate biodegradation, this study was performed according to KS M ISO 14855-1, and there were two different soil conditions including a compost condition and an activated vermiculite condition as artificial soil. This experiment was tested for 40 days. The measurement of carbon-dioxide generation was processed every 24 hour in 1-2 week, and every 48 hour after 3 week. In the same days, MDF showed 24.4% of biodegradation in compost condition, and 6.2% in activated vermiculite. Also, the reference material of TLC (thin-layer chromatography) grade cellulose showed 26.4%, 11.4% in compost and activated vermiculite respectively. The dilution plate method was performed for biological analysis in the study. This experiment was used for investigation of inoculum's (Bacillus licheniformis) activity. As the result of bioassay, compost has more other germs include inoculum than activated vermiculite in the first week. Especially in the 2nd week, the reference material under the compost condition showed the most germ's activity, and also the biodegradation was the highest. Consequentially, compost condition was able to reduce a performing period of biodegradation testing than activated vermiculite. However, activated vermiculite could be stabilizing errors between repetition.

• Corrosion Science and Technology
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• v.4 no.4
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• pp.147-154
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• 2005

The creep resistance of geogrids is one of the most significant long-term safety characteristics used as the reinforcement in slopes and embankments. The failure of geogrids is defined as creep strain greater than 10%. In this study, the accelerated creep tests were applied to polyester geogrids at various loading levels of 30, 50% of the yield strengths and temperatures using newly designed test equipment. Also, the new test equipment permitted the creep testing at or above glass transition temperature($T_g$) of 75, 80, $85^{\circ}C$. The time-dependent creep behaviors were observed at various temperatures and loading levels. And then the creep curves were shifted and superposed in the time axis by applying time-temperature supposition principles. The shifting factors(AFs) were obtained using WLF equation. In predicting the lifetimes of geogrids, the underlying distribution for failure times were determined based on identification of the failure mechanism. The results confirmed that the failure distribution of geogrids followed Weibull distribution with increasing failure rate and the lifetimes of geogrids were close to 100 years which was required service life in the field with 1.75 of reduction factor of safety. Using the newly designed equipment, the creep test of geogrids was found to be highly accelerated. Furthermore, the time-temperature superposition with the newly designed test equipment was shown to be effective in predicting the lifetimes of geogrids with shorter test times and can be applied to the other geosynthetics.

• Tribology and Lubricants
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• v.33 no.1
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• pp.31-35
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• 2017

Recently, international attention has been focused on the development of non-traditional energy resources such as shale gas and oil sands, due to the steep increase in the demand for natural resources. The materials incorporated in an oil gas plant module experience extreme environments, and are prone to various problem such as fracture, corrosion and abrasion due to low-temperature brittleness. In order to improve the plant life, it is necessary to perform characteristics study and performance evaluation of the materials. In particular, this paper explains the main set of materials which are most frequently used in oil sands plant project. In order to investigate wear characteristics, the authors carried out abrasive wear tests of TP 316, stainless steel and SS 400, structural rolled steel. For the analysis of the abrasive wear resistance of an oil sands plant, the authors carried out the test according to ASTM G 105 "Standard Test Method for Conducting Wet Sand/Rubber Wheel Abrasion Test" standard guidelines. The authors have derived the results from the data associated with the loss of mass with respect to wear rate. During the test, for a given wear length for 10,000 revolutions, the rotational speed and applied force of the rubber wheel were varied.

• Development and Reproduction
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• v.19 no.2
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• pp.111-118
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• 2015

This article explores the questions regarding PND and PID, especially the concrete legal conditions for the justification of PND and PID. As such, the German law stipulating PND and PID in a very concrete and detailed manner is introduced and explained in comparison with the corresponding South Korean law. The South Korean Bioethics and Biosafety Act (BBA) stipulates various types of gene testing and does not demonstrate a delicate sense of each type of gene testing. In contrast to the South Korean regulation, in Germany, there exist specific regulations for genetic counseling. Especially in the case of PND, GEKO stipulates the process of genetic counseling very concretely, based on GenDG. In the case of PND and PID, it is important that the people concerned understand the meaning of testing in various angles, and restructuralize it by combining it with their own values as the diagnosis is directly combined with pregnancy/abortion, which influences the whole life of a woman (and her partner). In this context, the South Korean BBA needs to be amended as soon as possible. The sections on informed consent also need to be amended to make them more concrete. Furthermore, guidelines for concretizing the regulation of BBA need to be continuously formulated and developed.

• Smart Structures and Systems
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• v.6 no.3
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• pp.263-275
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• 2010

In the last decade, wireless sensor networks have emerged as a promising technology that could accelerate progress in the field of structural monitoring. The main advantages of wireless sensor networks compared to conventional monitoring technologies are fast deployment, small interference with the surroundings, self-organization, flexibility and scalability. These features could enable mass application of monitoring systems, even on smaller structures. However, since wireless sensor network nodes are battery powered and data communication is the most energy consuming task, transferring all the acquired raw data through the network would dramatically limit system lifetime. Hence, data reduction has to be achieved at the node level in order to meet the system lifetime requirements of real life applications. The objective of this paper is to discuss some general aspects of data processing and management in monitoring systems based on wireless sensor networks, to present a prototype monitoring system for civil engineering structures, and to illustrate long-term field test results.

• Smart Structures and Systems
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• v.6 no.3
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• pp.239-262
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• 2010

Tube Lines has carried out a "knowledge and investigation programme" on the deep tube tunnels comprising the Jubilee, Northern and Piccadilly lines, as required by the PPP contract with London Underground. Many of the tunnels have been in use for over 100 years, so this assessment was considered essential to the future safe functioning of the system. This programme has involved a number of generic investigations which guide the assessment methodology and the analysis of some 5,000 individual structures. A significant amount of investigation has been carried out, including ultrasonic thickness measurement, detection of brickwork laminations using radar, stress measurement using magnetic techniques, determination of soil parameters using CPT, pressuremeter and laboratory testing, installation of piezometers, material and tunnel segment testing, and trialling of remote photographic techniques for inspection of large tunnels and shafts. Vibrating wire, potentiometer, electro level, optical and fibre-optic monitoring has been used, and laser measurement and laser scanning has been employed to measure tunnel circularity. It is considered that there is scope for considerable improvements in non-destructive testing technology for structural assessment in particular, and some ideas are offered as a "wish-list". Assessment reports have now been produced for all assets forming Tube Lines' deep tube tunnel network. For assets which are non-compliant with London Underground standards, the risk to the operating railway has to be maintained as low as reasonably practicable (ALARP) using enhanced inspection and monitoring, or repair where required. Monitoring techniques have developed greatly during recent years and further advances will continue to support the economic whole life asset management of infrastructure networks.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.415-418
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• 2011

Thermal fatigue is one of the life-limiting damage mechanisms in the nuclear power plant conditions. The turbulent mixing of fluids of different temperatures induces rapid temperature changes to the pipe wall. The successive thermal transients cause varying cyclic thermal stresses. These cyclic thermal stresses cause fatigue crack nucleation and growth similar to the cyclic mechanical stresses. The aim of this study was to fulfil the need by developing an real crack manufacturing method, which would produce realistic cracks. The test material was austenitic STS 304, which is used as pipelines in the reactor coolant system of a nuclear power plants. In order to fabricate thermal fatigue crack similar to realistic crack, successive thermal transients were applied to the specimen. Thermal transient cycles were combined with heating (60sec) and cooling cycle (30sec). And, In order to identify ultrasonic characteristic, it was performed the ultrasonic reflection measuring method for the fabricated specimen. From the results of ultrasonic reflection measuring testing, it was conformed that A-scan results(average 83% of real crack depth) for the TFC reference specimen was more enhanced NDT reliability than results(average 38% of real crack depth) for the EDM notch reference specimen.

• Proceedings of the KIEE Conference
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• summer
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• pp.560-562
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• 2004

$SF_6$ gas has been increasingly used as the insulating and arc-suppressing medium in switchgears which are used as the protection devices of power system. Nowadays, most of power companies adopted the $SF_6$ gas-type load break switch for increasing the reliability of distribution network by its superior durability against external environmental condition, in substitution for air-type and oil-type switches. But, it is important to establish the general estimation process for the testing and estimation for long-term reliability Accordingly, the national standard(RS C0031) was made for the reliability assessment of $SF_6$ gas load break switch and the testing facilities were also set in KERI(Korea Electrotechlology Research Institute). This paper presents the requirements of RS C0031 for reliability assessment of $SF_6$ gas load break switch and synopsis of the accelerated life testing facilities for $SF_6$ gas load break switch.

• Animal Bioscience
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• v.37 no.4
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• pp.600-608
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• 2024

Objective: In this study, we aimed to evaluate the usability single nucleotide polymorphisms (SNPs) for parentage testing of horse breeds in Korea. Methods: The genotypes of 93 horse samples (38 Thoroughbred horses, 17 Jeju horses, 20 Quarter horses, and 18 American miniature horses) were determined using 15 microsatellite (Ms) markers (AHT4, AHT5, ASB2, ASB17, ASB23, CA425, HMS1, HMS2, HMS3, HMS6, HMS7, HTG4, HTG10, LEX3, and VHL20) and 101 SNP markers. Results: Paternity tests were performed using 15 Ms markers and 101 SNP markers in Thoroughbred horses and Quarter horses. AHT5, ASB2, ASB17, ASB23, CA425, HMS7, HTG10, and LEX3 did not follow Mendelian inheritance in Thoroughbred horses, whereas in Quarter horses, only AHT4, ASB2, and HMS2 showed Mendelian inheritance, consequently, paternity was not established. Meanwhile, 31 markers, including MNEc_2_2_2_98568918_BIEC2_502451, in Thoroughbred horses, and 30 markers, including MNEc_2_30_7430735_BIEC2_816793, in Quarter horses did not conform with Mendelian inheritance and therefore, could not be used for establishing parentage. Conclusion: The possibility of replacing Ms markers with SNP markers for paternity testing in horses was confirmed. However, further research using more samples is necessary.

• Journal of Korean Institute of Industrial Engineers
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• v.12 no.1
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• pp.139-146
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• 1986

This study is concerned with the development of statistical life test plans for the mean lifetime of an item whose underlying lifetime distribution is a two parameter Weibull, which is perhaps the most widely used lifetime model. For this purpose, I used the likelihood ratio test method, and I verified the developed test plans and determined the sampling size and censoring number by computer similation.