• Transactions of the Korean hydrogen and new energy society
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• v.22 no.1
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• pp.51-59
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• 2011

Sulfur-Iodine (SI) cycle, which thermochemically splits water to hydrogen and oxygen through three stages of Bunsen reaction, HI decomposition, and $H_2SO_4$ decomposition, seems a promising process to produce hydrogen massively. Among them, the decomposition of $H_2SO_4$ ($H_2SO_4=H_2O+SO_2+1/2O_2$) requires high temperature heat over $800^{\circ}C$ such as the heat from concentrated solar energy or a very high temperature gas-cooled nuclear reactor. Because of harsh reaction conditions of high temperature and pressure with extremely corrosive reactants and products, there have been scarce and limited number of data reported on the pressurized $H_2SO_4$ decomposition. This work focuses whether the $H_2SO_4$ decomposition can occur at high pressure in a noble-metal reactor, which possibly resists corrosive acidic chemicals and possesses catalytic activity for the reaction. Decomposition reactions were conducted in a Pt-lined tubular reactor without any other catalytic species at conditions of $800^{\circ}C$ to $900^{\circ}C$ and 0 bar (ambient pressure) to 10 bar with 95 wt% $H_2SO_4$. The Pt-lined reactor was found to endure the corrosive pressurized condition, and its inner surface successfully carried out a catalytic role in decomposing $H_2SO_4$ to $SO_2$ and $O_2$. This preliminary result has proposed the availability of noble metal-lined reactors for the high temperature, high pressure sulfuric acid decomposition.

• Membrane Journal
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• v.9 no.1
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• pp.36-42
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• 1999

Permeation behavior of the semiconductor rinsing wastewater contammg Si particles was examined by ultrafiltration using the polyolefin tubular membrane. Flux decline with time was due to the growth of Si cake deposited on the membrane surface and the pore plugging by Si particles. Cake filtration from the cross flow application is compared to the combination of pore blocking and cake filtration from the dead-end application. The cake resistance is 3.16 x $10^{12}$ -4.34 X $\times$$10^{12}$ $m^{-1}$ for the cross flow and 6.6 x $\times$$10^{12}$ -12.19 X $\times$$10^{12}$ $\times$$m^{-1}$for the dead-end flow, respectively. At the initial stage of operation, permeation flux of cross flow type was 1.7 time higher than that of the dead end flow type. Permeation flux of cross flow was about 42 e 1m2 hr and the rejection rate of Si particles was about 96 %. The average particle size of Si particle in the permeate was 20 nm.

• Smart Structures and Systems
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• v.6 no.7
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• pp.835-849
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• 2010

This study investigated propagation characteristics of piezo-activated guided waves in an aluminium rectangular-section tube for the purpose of damage identification. Changes in propagating velocity and amplitude of the first wave packet in acquired signals were observed in the frequency range from 50 to 250 kHz. The difference in guided wave propagation between rectangular- and circular-section tubes was examined using finite element simulation, demonstrating a great challenge in interpretation of guided wave signals in rectangular-section tubes. An active sensor network, consisting of nine PZT elements bonded on different surfaces of the tube, was configured to collect the wave signals scattered from through-thickness holes of different diameters. It was found that guided waves were capable of propagating across the sharp tube curvatures while retaining sensitivity to damage, even that not located on the surfaces where actuators/sensors were attached. Signal correlation between the intact and damaged structures was evaluated with the assistance of a concept of digital damage fingerprints (DDFs). The probability of the presence of damage on the unfolded tube surface was thus obtained, by which means the position of damage was identified with good accuracy.

• Journal of the Korean Home Economics Association
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• v.12 no.34
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• pp.663-677
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• 1974

The social and psychological approaches to clothing researches by Fluge,l, Hurlock and Barr in the early 1930's have since been developed greatly. It has now been generally agreed that clothing is the symbol of one's personality and social status, for clothing is regarded as the second skin and a manifestation of one's emotional states as well. Based on this consensus, this study was intended to observe the possible relationship between one's clothing design preference-in line, color and texture- and interest. For this survey, 200 college woman students from four universities were selected at random, and an interest-test standardized by prof. Jung Bum Mo and a questionaire made of 20 items on the clothing prferences were given. The results as commputerized and analyzed are as follows : 1. Line Preference a) Structural line : It is quite obvious that those like straight line are interested in fine arts, and curved line in physics. b) Out-line : Among tubular, bell and bustle of the silhouette, those like the bustle have shown particular interest in music, and the tubular in politics and business. c) Style : There is a salient tendency that those like a dressy style are much interested in music, and casual style in physics and physical exercise. 2. Color Preference a) Favorite color : Those like red, orange and yellow show a high interest in artistic activities and physical exercise, and black, grey and white in politics. b) Variety and combination of color ; These have shown no relationship to the interest. 3. Texture Preference a) The touch : Those like the texture with the feeling the crisp and rough are interested in fine arts, and of soft and smooth in the field of social service. b) Fabric surface : Those like naturalistic pattern, i.e. print of flowers, show much interest in music and literature, and plain fabrics in physical exercise.

• Parasites, Hosts and Diseases
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• v.29 no.1
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• pp.43-54
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• 1991

An in vitro immune effector mechanism against the target encysted metacercariae of Paragonimus westermani was demonstrated in the rat system. Peritoneal exudate cells, mainly macrophages from normal rats, showed adherence to and killing of encysted metacercariae of p. westermani in the presence of complement-independent serum from rats infected with Paragonimus metacercariae. These reactions were specific for the excysted metacercariae, as tissue-migrating juvenile worms were not affected. Damage of encysted metacercariae of p. westermani due to antibody and macrophages was assessed by morphological observation, by cell adherence reaction and by the use of vital dyes. frypan blue dye exclusion proved to be a reliable indicator of judging metacercarial viability. Electron microscopic studies demonstrated that macrophages reacted with fusty material on the tegumental surface and fine structures in the syncytium of the parasites. The tubular tunnels formed between the basement membrane and muscle layers of the damaged parasites were also noticeable. The relevance of these findings to cellular immunity in the early paragonimiasis was discussed.

• Korean Journal of Veterinary Service
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• v.22 no.2
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• pp.113-119
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• 1999

The most common cause of death is ostrich chick fading syndrome(OCFS), which is due to bacterial infection during artificial incubation and hatching. Six farmed ostrich chicks aged 3 and 10 days in Chonbuk province, were submitted to Chonbuk Livestock Development and Research Institute for necropsy, Clinically, birds showed hair loss, ocular exudate, lethargy, diarrhea, and subsequently died 3-5 days after onset of clinical signs. Grossly, umbilicus was enlarged. White-yellowish purulent nodules were scattered on the lung and the membrane of air-sac was thickened and had inflamed exudate on the surface in two chicks that died 3 days after hatching. In 10 days-old chick, intestine was shown rodding segmentally. Yolk sac was still retarded and its surface was partially hemorrahgic. The synovial fluid of the leg was yellowish. Microscopically, multifocal purulent exudates were scattered on the lung. Capillary microthrombi in the glomerulus were prominent and tubular epithelia were necrotic. Necrotic hepatocytes were scattered and intestine were congested. Microbiologically, Pseudomonas sp and/or E coli were isolated from air-sac, lung and/or liver. This case suggests that poor hygiene during artificial incubation, hatching or in the first week after hatching may cause high mortality of the ostrich chicks.

• Korean Journal of Veterinary Research
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• v.45 no.1
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• pp.99-103
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• 2005

We report septicemic colibacillosis accompanied by white-spotted kidney in a 30-day old female Holstein-Friesian dairy calf. Grossly, there were numerous white spots sized average 0.5cm in diameter in both kidneys. When sectioned sagittally, there were radially oriented gray streaks extending outward and reaching the renal cortex. The renal papillae were ulcerated, white to gray in color and very friable. Histologically, there was extensive purulent inflammation characterized by severe neutrophilic cellular infiltrations in the tubular lumens and interstitia. In addition, massive coagulative necrosis were found in the apices of papillae. Numerous Gram-negative bacterial colonies were detected in both of the renal and lung tissues. Beta-hemolytic Escherichia coli (E. coli) was purely isolated from the renal parenchyma, peritoneal surface and pleural surface. Based on the above results, we suggest that the generalized septicemia with pyelonephritis may be oriented from the lower urinary tract infection with E. coli in this case.

• Structural Engineering and Mechanics
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• v.77 no.1
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• pp.75-87
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• 2021

The present study pertains to the introduction of two new types of grip adaptor for universal testing machines, namely Polyvinyl Chloride (PVC) and Polyoxymethylene (POM) grip adaptors, and their application to tension testing of FRP bars with different fiber and surface finish types. The tabs are connected to the FRP bar sample with the help of mechanical anchors, i.e. bolts. These new adaptors offer vital superiorities over the existing end tab designs (anchors with filling material or mechanical anchorage), including the reduction in the time and labor for production, reusability and the mild nature, i.e. low hardness of the tab material, which retards and even prevents peeling and crushing in the gripping regions of an FRP sample. The methods were successfully applied to FRP bars with different types of fiber (CFRP, GFRP and BFRP) and different types of surface texture (ribbed, wrapped, sand-coated and wound). The test results indicated that the both types of end caps prevented slip of the bar, crushing and peeling in the gripping zone. The mechanical properties from the material tests with the new caps were in perfect agreement with the ones from the material tests with steel tubular caps.

• Geomechanics and Engineering
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• v.29 no.3
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• pp.229-236
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• 2022

In this study, a model experiment and field experiment was conducted to introduce the optimal tensile force when constructing a non-open cut tunnel according to the ground conditions of sandy soil. CMR (Concrete Modular Roof) method is economical because of the high precision and excellent durability, and corrosion resistance, and the inserted parts can be used as the main structure of a tunnel. In addition the CMR method has a stable advantage in interconnection because the concrete beam is press-fitted compared to the NTR (New Tubular Roof) method, and the need for quality control can be minimized. The ground conditions were corrected by adjusting the relative density of sandy soil during the construction of non-open cut tunnels, and after introducing various tensile forces, the surface settlement according to excavation was measured, and the optimal tensile force was derived. As a result of the experiment, the amount of settlement according to the relative density was found to be minor. Furthermore, analysis of each tensile force based on loose ground conditions resulted in an average decrease of approximately 22% in maximum settlement when the force was increased by 0.8 kN per segment. Considering these results, it is indicated that more than 2.0 kN tensile force per segment is recommended for settlement of the upper ground.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.83-86
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• 2008

In this study, friction test was proposed to obtain coefficient of friction between tube and die in guide zone of tube hydroforming and friction coefficients were evaluated at different materials, viscosity of lubricants and internal pressures. For this study, STKM11A and SUS tubes were prepared. The tube was expanded by an internal pressure against the tool wall. By pushing the tube through the tool, a friction force at the contact surface between the tube and the tool occurs From the recorded axial feeding forces, the friction coefficients between tube and die at the guide zone in tubular hydroforming can be estimated. The effects of the various internal pressures, viscosity of lubricants, tube materials, tube size and die coating on the friction forces and friction coefficients are discussed.