• Tunnel and Underground Space
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• v.23 no.3
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• pp.180-191
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• 2013

The purpose of this research was to find an optimal quarrying for marble by analyzing the applicability and the work efficiency of a chain saw machine newly introduced in the underground Baekwoon mine. From the test results of the physical properties of Baekwoon marble, which affects the efficiency of rock cutting, it was found to have similar physical characteristics as the ones which are now being produced in the other areas in Korea. And especially it shows isotropic property, which can be thought to be advantageous as a dimensional stone. To check the long-term quality of the marble as a stone material, several tests such as corrosion resistance test and abrasion test were carried out. It was found to be vulnerable to acid rain with decrease of weight and seismic wave velocity after applying artificial rain at pH 5.6 for 50 times. The percentage of wear from abrasion test was 22.67%. The working time and cutting speed of the chain saw machine were recorded and analyzed during the test-run at the quarry. The overall work cycle was assorted into 9 unit operations and the operating time per each unit was drawn. The operating times for the two cutting patterns, which could be possibly applicable to the work site, were compared. The results indicated that the pattern B, that the cutting sequence was set to minimize the movement of the machine, showed 6% less working hours than the pattern A, which first cuts the outer boundary. With cutting pattern analysis, the ore body in the Baekwoon mine was 3 dimensionally modeled and a quarrying plan considering the existing conditions of the marble was suggested.

• Parasites, Hosts and Diseases
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• v.36 no.1
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• pp.7-14
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• 1998

In order to understand the action mechanism of polyhexamethylene biguanide (PHMB) to the cyst of Accnthcnloebc on the morphological basis, the cysts of four corneal isolates of Acanthanoebc were treated with minimal cysticidal concentration (MCC) of PHMB and their ultrastructural changes were examined by transmission electron microscopy. The most striking change of cysts treated with PHMB compared with normal cysts was the shrinkage of intracystic amoebae, which resulted in the separation of the plasma membrane of intracystic amoeba from endocystic wall. Subplasmalemmal lipid droplets became irregularly shaped . In severely damaged cysts, cytoplasm was aggregated and organelles were severely deformed. Cytoplasmic materials were leaked out through the damaged plasma membrane. Most cysts showed aggregation of nuclear chromatin material. Number of mitochondrial cristae was also reduced. Ecto- and endo-cystic walls were relatively well tolerated. Findings in the present study revealed that PHMB affected mainly on plasma membrane, but lesser on organellar membrane of intracystic amoeba. It seemed likely that PHMB might kill cystic forms of Accnthamoebc by similar mechanism in which this environmental biocide can damage the cell wall of Escherichia coli by binding with acidic phospholipids.

• Korean journal of food and cookery science
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• v.10 no.1
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• pp.39-44
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• 1994

For the purpose of supplying the basic knowledge to make Doenjang which is acceptable to Korean people three kinds of koji, namely rice, wheat, and soybean Koji were made with Aspegillus oryzae. Then Doenjangs were made with four different ratio of three Kinds of Koji. Components related to the taste of Boenjang were analyzed, sensory evaluation of Doenjang were made, and correlation between analytical variables and sensory parameters were investigated. The results were as followed 1. Total nitrogen contents of each Doenjang were increased with increasing the ratio of Koji except Doenjang made with soybean Koji. The amounts of amino nitrogen increased with the ratio of koji increases in each Doenjang. Amino nitrogen contents of Doenjang made with soybean Koji were highe. than the others, 2. Reducing sugar contents of rice and wheat Doenjang were similar, but amounts were increased with increasing the ratio of Koji Reducing sugar contents of Soybean Doenjang were lower than the others. pH of the Doenjangs decreased as the ratio of the koji increased. The amount of sweet taste amino acids and MSf; like amino acids were increased, but bitter taste amino acids were decreased as the ratio of the koji increased in rice and wheat Doeujang, The sweet taste amino acids and bitter taste amino acids in soybean Doenjang showed little Changes in amount, but the amount of MSG like amino acids increased as the ratio of the Koji increased from 13% to 25%, 37%, and 50%. The nucleotide contents of wheat Doenjang were higher than other Doenjangs, and there is a tendency to increase the amounts of nucleotide as increasing the ratio of koji in each Doenjang. 3. As a result of sensory evaluation, wheat Doenjang of 13% koji ranked highest in the overall eating quality, and Doenjangs made with 50% and 37% of rice koji ranked next, 4. pH and sweet tast amino acids influenced on the Overall eating quality of the Doenjang, however most compo-nents of the Doenjang seemed to relate to overall eating quality of Doenjang, however most components of the Doenjang seemed to relate to overall eating quality of Doenjang.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4635-4642
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• 2010

Latex modification of concrete provides the material with higher flexural strength, as well as high bond strength and reduced water permeability. One of the most advantages of the very early-strength latex-modified concrete (VES-LMC) could be the similar contraction and expansion behaviour to normal concrete substrate, which enable to ensure long-term performance. The purpose of this study was to parametric nonlinear flexural nonlinear analysis of RC beam rehabilitated by VES-LMC. The results were as follows; The flexural nonlinear analysis model of RC beam overlaid by VES-LMC in ABAQUS was proposed to predict the load-deflection response, interfacial stress, and ultimate strength. The proposed FE analysis model was verified by comparison of an experimental data and the FE analysis results. The FE analysis results showed that yield point as well as flexural stiffness increased as the depth increased; the stiffness of beam overall increased as the bond stiffness became larger; the bond strength between two different materials is a key factor in composite beam. A parametric study showed that an overlay thickness was a main influencing factor to the behavior of RC beam overlaid by VES-LMC.

• Resources Recycling
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• v.21 no.1
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• pp.60-65
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• 2012

The Ti-6Al-4V alloys were prepared by recycling of dental Ti pure scraps using vacuum arc melting process, and their physical properties were evaluated the Ti-6Al-4V alloys with different oxygen concentrations. For the preparation of Ti-6Al-4V alloys, Ti pure scraps used for dental implant were utilized as a raw material, and their different oxygen concentrations were ranged from G1 to G4 grade in ASTM standards. It was confirmed that the weight loss of Al in the composition of Ti-6Al-4V alloy could be controlled under the Ar pressure of 875 torr during the melting of alloy. The oxygen concentrations of the Ti-6Al-4V alloys were ranged from 1170 to 3340 ppm. The vickers hardness change of the Ti-6Al-4V alloys showed a similar behavior with that of pure Ti. As a result, we confirmed a possibility of preparation of Ti-6Al-4V alloy by recycling of dental Ti scraps using vacuum arc melting process in this study.

• Journal of the Korean GEO-environmental Society
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• v.17 no.5
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• pp.27-36
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• 2016

Low Impact Development (LID) techniques are eco-friendly storm water management process for water circulation restoration and non-point pollutant reduction. In this study, four LID techniques (Small constructed wetland, Infiltration trench box, Infiltration trench, Vegetated swale) were selected and installed as a real size at the real site. All facilities were evaluated as monitoring under the real environmental climate situation and an artificial rain with exceeding design rainfall. In various rainfall, runoff reduction efficiency and non-point pollutant removal efficiency are increased to the bigger Surface Area of LID (SA)/Catchment Area (CA) ratio and the bigger Storage Volume of LID (SV)/Catchment Area (CA) ratio. Runoff did not occur at all rainfall event (max. 17.2 mm) in infiltration trench and vegetated swale. But Small constructed wetland was more efficient at less than 10 mm, a efficiency of infiltration trench box was similar at different rainfall. Although different conditions (such as structural material of LID, rainfall flow rate, antecedent dry periods), LID techniques are good effects not only water circulation improvement but also water quality improvement.

• (The)Study of the Eastern Classic
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• no.62
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• pp.209-229
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• 2016

This thesis is to discover the meanings of boundary through East Asian thought so as to make rooms for discoursing on it. First of all people have their own boundaries of 'Me', and they make others as persons or objects in their thoughts. Originally boundary has represented nation's frontier, and it indicated the worlds of space in Buddhism of East Asian culture. It is represented by loka or visaya in Sanskrit and region, dominion, boundary, border in English, which means the worlds that people would fancy in their minds over domains of politics, societies, culture, arts ect, not to be simple. Accordingly we must not approach to its meaning simply like 'beyond border'. There are many boundaries, which are similar to the sublime, for us to arrive in our lives. Spiritually there are also many boundaries(regions) that are made by our desires, wills and concepts. In a while there are limit or problem in our recognizing things, for example, of human's five senses that would be, to an extent connected with Buddhistic understanding of boundaries. Boundaries resulted from partiality in understanding of objects must be got rid of eventually. In regard of these matters, this thesis discusses the meanings of boundary, those that are inevitably made by human's consciousness, and negative ones to be got over from recognition systems of person or any groups.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.29-34
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• 2012

To examine possibilities to make use of woodceramics for the lower material of hot-floored ondol boards, woodceramics made from sawdust board with Pinus densiflora, put them in a wood frame and concrete block and heated them sending an electric current, and measured changes in surface temperature of a laminated floor board and a plywood floor board. As the sending an electric current to time passed, their surface temperature increased rapidly up to 20 minutes, and then gradually ascended. In terms of the surface temperature in the wood frame, the beginning temperature of a plywood floor board was higher than that of laminated floor one; however, as time passed, a laminated floor board's temperature rose, and after 60 minutes, it showed similar to the temperature of a floor board of lamination. On the other hand, the surface temperature in a concrete block showed that the laminated floor board was higher than the plywood floor board in both early and 60-minute later temperatures. With the lapse of time after switching off, the surface temperature of floor boards slowly dwindled up to 9 minutes, and from that time on, began to drop sharply. In terms of the descent speed of surface temperature, when woodceramics' surface temperature was adjusted at $70^{\circ}C$, the laminated floor board was the highest; when it was at $80^{\circ}C$, the plywood floor board was the highest, resulting in rapid descent speed of heat.

• Textile Coloration and Finishing
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• v.31 no.3
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• pp.195-213
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• 2019

The purpose of this study was to identify novel extracts of brawn algae with the high deodorant capacity and antioxidant activity. To achieves this, an composition, deodorant performance and free radical scavenging activity were analyzed in powder and water extracts of Ecklonia cava(PEC/EEC), Saccharina japonica(PSJ/ESJ), Eisenia bicyclis(PEB/EEB), Sargassum spp.(PSS/ESS) and Hizikia fusiformis(PHF/EHF) using several analytical methods. Major component of five powders was verified as PEC, phlorotannin; PSJ, alginic acid and glutamic acid; PEB, carotenoid, chlorophyll, phlorotannin, tocopherol and fucoxantin; PSS, ${\beta}$-carotene and polyphenol; PHF, tannin. The highest level of DPPH scavenging activity was detected in EEC($IC_{50}=23.018{\mu}g/ml$), followed by EEB, ESJ, EHF and ESS. The deodorizing performance to ammonia was maintained high level in PEC, PSJ, PEB and PSS, while PHF showed low level in the same condition. But, the deodorizing performance to acetic acid was slightly higher in PSJ and PEC than those of PEB, PSS and PHF. Based on the results of DPPH scavenging activity and deodorizing capacity, we selected fractions of S. japonica as leading extracts and further prepared the 70% acetone extract (AESJ) and 70% ethanol extract (EESJ) from PSJ. The contents of total flavonoid, total phenol and total condensed tannin was significantly increased with 112-209% in AESJ and EESJ compared to those of ESJ. Also, a similar enhancement was observed on the level of DPPH scavenging activity and deodorizing performance against ammonia/acetic acid in AESJ and EESJ. Therefore, these results suggest that AESJ and EESJ contained with high total phenol and total condensed tannin contents may exhibit high deodorant capacity and antioxidant activity as well as has the potential for use as a powerful biomaterial for antibacterial deodorant.

• The Korean Journal of Malacology
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• v.27 no.2
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• pp.149-157
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• 2011

Some characteristics of the formations of acrosomal vesicles during the late stage of spermatids during spermiogenesis and taxonomical charateristics of sperm morphology in male two species (Saxidomus purpurata and Meretrix petechialis) in the family Veneridae were investigated by electron microscope observations. In two species, the morphologies of the spermatozoa have the primitive type and are similar to those of other bivalves in that it contains a short midpiece with five mitochondria surrounding the centrioles. The morphologies of the sperm nuclear types of S. purpurata and M. petechialis in Veneridae have the curved cylindrical and cylinderical type, respectively. And the acrosome shapes of two species are the same cap-shape type. In particular, the axial filament is not found in the lumen of the acrosome of two species, however, subacrosomal material are observed in the subacrosomal spaces between the anterior nuclear fossa and the acrosomal vesicle of two species. The spermatozoon of S. purpurata is approximately 46-$52{\mu}m$ in length, including a curved sperm nucleus (about $3.75{\mu}m$ in length), a long acrosome (about $0.40{\mu}m$ in length),and a tail flagellum (about 45-$47{\mu}m$ long). And the spermatozoon of M. petechialis is approximately 47-$50{\mu}m$ in length including a slightly curved sperm nucleus (about $1.50{\mu}m$ in length), an acrosome (about $0.56{\mu}m$ in length) and tail flagellum (44-$48{\mu}m$ in length). In two species, the axoneme of the sperm tail flagellum of each species consists of nine pairs of microtubules at the periphery and a pair of cental doublets at the center. Therefore, the axoneme of the sperm tail flagellum shows a 9 + 2 structure. In particular, taxonomically important some charateristics of sperm morphologies of two species in the family Veneridae are acrosomal morphology of the sperm, The axial filament is not found in the acrosome as seen in a few species of the family Veneridae in the subclass Heterodonta. The acrosomal vesicle is composed of right, left basal rings and the apex part of the acrosomal vesicle. In particular, right and left basal rings show electron opaque part (region), while the apex part of the acrosomal vesicle shows electron lucent part (region). These charateristics belong to the subclass Heterodonta, unlikely a characteristic of the subclass Pteriomorphia showing all part of the acrosome being composed of electron opaque part (region). Therefore, it is easy to distinguish the families or the subclasses by the acrosomal structures. The number of mitochondria in the midpiece of the sperm of S. purpurata and M. petechialis in Veneridae are five. However, the number of mitochondria in the midpiece of the sperm in most species of Veneridae in the subclass Heterodonta are four. Therefore, the number of mitochondria of the sperm midpiece of two species are exceptionally 5, and it is only exceptional case in the species in Veneridae in the subclass Heterodonta. Except these cases, the number of mitochondria in the sperm midpiece in all families in the subclass Heterodontaare are 4, and now widely used in taxonomic analyses.