• Tunnel and Underground Space
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• v.25 no.3
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• pp.293-302
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• 2015

Thin Spray-on Liner (TSL) has been considered as a new rock support to replace shotcrete as well as wire mesh. However, the development of its original production technology is highly in demand since it is not open to the public. Therefore, two kinds of powder-type TSL prototypes were developed as the first development stage. Then, their mechanical properties were experimentally compared with those of a two-component foreign TSL material including both of liquid and powder components. From a series of experiments, the first TSL prototype mixing condition satisfied every TSL performance requirements specified by EFNRAC (2008), and showed much higher tensile and bond strengths than those of the two-component foreign TSL, even though the other TSL prototype cannot be used as a support member since its elongation at break is much lower than its corresponding EFNARC (2008) performance criterion. In addition, a further study to increase the ductility of the first TSL prototype might be necessary to guarantee its higher applicability to field conditions.

• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.163-171
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• 2014

Environmental issues about indoor air quality have been increased and focused on volatile organic compounds (VOCs) caused cancer, asthma, and skin disease. Reducing VOCs has been attempted in many different methods such as using environmentally friendly materials and air cleaner or purifier. Charcoal is well known material for absorbing VOCs. Therefore, carbonized board from medium density fiberboard has been developed. We assumed that the source of carbonized boards can be any type of wood-based panels. In this study, carbonized boards were manufactured from oriented strand board (OSB) at 400, 600, 800, and $1000^{\circ}C$. Each carbonized OSB (c-OSB) was evaluated and determined physiomechanical characteristics such as exterior defects, dimensional shrinkage, modulus of elasticity, and bending strength. No external defects were observed on c-OSBs at all carbonizing conditions. As carbonizing temperature increased, less porosity between carbonized wood fibers was observed by SEM analysis. The higher rate of dimensional shrinkage was observed on c-OSB at $1000^{\circ}C$ (66%) than c-OSB at 400, 600, and $800^{\circ}C$ (47%, 58%, and 63%, respectively). The densities of c-OSBs were lower than original OSB, but there was no significant different among the c-OSBs. The bending strength of c-OSB increased 1.58 MPa (c-OSB at $400^{\circ}C$) to 8.03 MPa (c-OSB at $1000^{\circ}C$) as carbonization temperature increased. Carbonization temperature above $800^{\circ}C$ yielded higher bonding strength than that of gypsum board (4.6 MPa). In conclusion, c-OSB may be used in sealing and wall for decorating purpose without additional artwork compare to c-MDF which has smooth surface.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.12
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• pp.1585-1590
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• 2012

Engineering plastics are used in instrument panels, interior trim, and other vehicle applications, and the thermomechanical behaviors of plastic materials are strongly influenced by many environmental factors such as temperature, sunlight, and rain. As the material properties change, the mechanical parts create unexpected noise. In this study, the dynamic mechanical property changes of plastics used in automobiles are measured to investigate the temperature effects. Viscoelastic properties such as the glass transition temperature and storage modulus and loss factor under temperature and frequency sweeps were measured. The data were compared with the original ones before aging to analyze the behavior changes. It was found that as the temperature increased, the storage modulus decreased and the loss factor increased slightly.

• Applied Biological Chemistry
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• v.43 no.1
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• pp.67-71
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• 2000

Termiticidal activities of Chamaecyparis obtusa were quantitatively evaluated, and the activity differences between supporting materials such as woodmeal and filter paper or between species were defined based on the termiticidal activity value(TAV). It was found that TAV was high in the following order ; C. obtusa>Litsea coreana>C. obtusa var. formosensis>Ternstroemia gymnanthera. In particular, termiticidal activity of C. obtusa heartwood was stronger by 5 to 9 times than that of other three species. Median survival dosage(MSD) of C. obtusa was 108.8 mg. In case of woodmeal or filter paper tests with C. obtusa, termiticidal activities were inversely proportional to logarithms values of an added sample weight and median survival time(MST). The difference of termiticidal activities between woodmeal and filter paper in the methanol extracts was small, but that in the neutral fraction was enormous as 3.21 times. However, termiticidal activity of neutral fraction was corresponded to 17 to 53% of original woodmeal, and 47 to 83% of termiticidal activity was considered as a loss in test process.

• Journal of Biosystems Engineering
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• v.31 no.3 s.116
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• pp.161-167
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• 2006

The purpose of this study is to find the optimal conditions of PCM slurry manufacturing equipment for saving the marketing cost and keeping the original quality of products. In addition, the characteristics of the movable container for shipping or distributing products is analysed. The major results are as follows. 1. PCM thermal storage system is designed with the conditions of temperature($-5{\sim}10^{\circ}C$), cold chain time(30 minutes), and one time usage(50 liter). This system includes tank, freezer, circulating pump, cycle type heat exchanger, swelling tank, equipment of supplying PCM supplying unit includes cold tank, cycle type heat exchanger, suction unit and control equipments, etc. 2. After ability test of PCM thermal storage system, it shows that the required freezing time of PCM thermal storage system is less than one of the previous system. The reason is that churn (top and bottom) and compulsion circulation are occurred simultaneously and unit cooler type method is better than chiller type method. 3. By the experiment of transportation latent heat container, it is decided that the best container is $K_1$ with latent heat temperature($0{\sim}5^{\circ}C$) and density(0.15%). However, for $K_l\;and\;K_2$, it is necessary more studies on latent heat thermal conditions and conditions of making method.

• Journal of Technology Innovation
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• v.14 no.3
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• pp.209-235
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• 2006

Since the end of the cold war, technical tie-up between private corporations and an army in developed countries has increased a lot, and the trend is spreading through developing countries rapidly. To cope with the circumstance actively, the dual use technology program for both private corporations and an army was begun in Korea in 1998. With the program, overlapping investment was resolved and technology transfer was stimulated. And the standardization and information exchange saved considerable national budget and made possible economic profit. Yet, the combination project of 4 ministries and offices showed problems such as loose cooperation and, low industralization record. However, developed countries are out of the mere stage of dual technology development and turn into broad technical tie-up including future prediction, national competitiveness improvement, and the private company's leading participation and they are systemizing them very fast. Korea also set up the national defense reform plan with the blueprint of future military force improvement, budget increase for national defense research, and increased participation of private corporations, and created Defense Acquisition program Administration to support them. The innovation of national defense system brings forward the need to link the private and military innovation. Korea has pursued the fast growth through assimilation, absorption, and improvement of foreign technology. But now, Korea has to focus on self innovation, original technology, parts and material. As this applies to private companies and military equally, it is important to concentrate limited resources for the effective technology cooperation. Considering this, the strategies to activate the dual use technology are program concept and range extension, task-deduction way improvement and future-oriented common task deduction, and promotion system improvement.

• Plant Biotechnology Reports
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• v.3 no.4
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• pp.317-324
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• 2009

The insecticidal toxin gene of Bacillus thuringiensis (Bt) is one of the most commonly used in the development of genetically modified (GM) crops. In this research, we analyzed Bt rice showing lepidopteran pest-resistance. The Bt gene is a synthetic Cry1Ac composed of optimal codons for plants, and the Bt protein is targeted to the chloroplast by a transit peptide. Three Cry1Ac rice events (C103-3, C127-1, and C7-1) were analyzed for molecular characterization. C103-3 contains two copies of T-DNA where the left border (LB) region is truncated. Both C7-1 and C127-1 have a single copy of T-DNA, but a part of the vector backbone DNA is inserted into the genome of C127-1; thus, only C7-1 had intact T-DNA. Progenies of C7-1 crossed with the original cultivar, Nakdong, and double-haploid lines from anther culture of lines crossed with the elite cultivar, Dongjin, were analyzed for T-DNA flanking genomic DNA and genotyping. Results showed that an intact T-DNA region without the vector backbone was inserted into the genome and was stably inherited through generations. The C7-1 homozygous event could be used as breeding material to develop GM rice with pest resistance.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.11b
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• pp.209-213
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• 1999

In the society of the 21\ulcorner century under multiphase media conditions, the rapidly glowing electronic media will replace the conventional paper media in a variety of areas. However, if human being still has an affinity for paper media and an instinct for hardcopy from electronic-based text or image, the new market will be created for the paper industry. To what extent the consumer choses paper media for output will depend upon the availability of functions of paper media appealing to human senses; i.e., "sensory functions of paper". As a whole, on-demand type personal as well as business communications will increase in the next century and this trend will lead certainly to a rapidly expanding "contents hardcopy market". The technological progress of the paper industry in the 21\ulcorner century depends upon the market needs for higher products quality and higher efficiency of manufacturing process as well as an endeavour to overcome constraints from forest resource, energy, and environmental issues. Under the conditions with above constraints, the paper media will be polarized into two categories; (1)paper for higher image reproduction capability for original image or text and (2)paper for lower reproduction but with higher appeals for human senses. To cope with these trends, psycho-physical analysis and a sensory engineering approach for developing new paper media is vitally required. Also newly emerged roles of paper physics in the multimedia age is pointed out associated with sensory functions of paper that are not well-understood so far.

• Journal of Fashion Business
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• v.16 no.1
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• pp.52-68
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• 2012

To achieve the aim of this study, 9 different types of samples were made to examine mechanical property according to structured pattern and type of Machi of pullover armhole of WholeGarment(seamless knitwear). With respect to samples, from which comparisons are made and anaylzed among basic characteristics of material, tensile strength & elongation and residual elongation due to repeated extension of armhole connecting part, the following conclusions could be obtained. It's revealed that the tensile strength of Machi part as being armhole connecting part of samples is more affected by Machi type than pattern structure. Of Machi types, it showed stronger tensile strength in the order of Normal(Normal Machi)< Machi_B(unilateral Machi)

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.3
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• pp.32-37
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• 1999

There is a need to suggest the standards of selection on the cuttings, because the selection of the willow(Salix) cuttings is very important, which will be used as the bioengineering revegetation material to protect the slope by strengthening soil and preventing soil erosion under the bad site conditions. In this study, we measured the lengths and the diameters of original willow cuttings, the total numbers and the lengths of the new shoots and roots after 15 months since the experimental construction of the slope revegetation technology of biological engineering was conducted, and analyzed the correlation between the lengths and the diameters of willow cuttings and the lengths of new roots using the SPSS program. The results are as follows; First, the lower the elevation of tested slope was, the more the number of new shoots and the average lengths of new roots increased. Secondly, the ratio of underground parts and aboveground parts was 4.24 ~ 5.93 proving the fact that the willow(Salix) is one of the species deep rooted with developed underground parts. Thirdly, there is a strong correlation between the diameters of willow cuttings and the total lengths of new roots, whereas, there is no correlation between the lengths of willow cuttings and the total lengths of new roots. In conclusion, it is more efficient for the early rapid revegetation and slope stabilization to select willow cuttings with the biggest possible diameters than with the longest lengths as the slope revegetation materials of biological engineering.