• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.11 no.1
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• pp.74-78
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• 2015

Nuclear power plant steam generator that is one of the main component has several thousands of thin tubes. And the steam generator tube is subject to damage because of the severe operation conditions such as the high temperature and pressure. Therefore periodic inspections are conducted to ensure the integrity of steam generator component. Hanul unit 3 also has been inspected in accordance with in-service inspection program and is scheduled to be replaced for exceeding the plugging rate which was recommended by manufacturer. During the steam generator replacement activity, we found several clustered porosity on inner surface of main feed water pipe. Additionally crack-like indications were found at weld interface between base material and weld of main feed water pipe. This paper describes the field experience and visual testing results for inner surface of main feed water pipes. The destructive test result had shown that these indications were porosities which were caused by manufacturing process not by operation service.

• The Journal of the Korea Contents Association
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• v.6 no.12
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• pp.163-168
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• 2006

Hg-free fluorescent lamps were fabricated and electro-optical characterization were measured for using LCD backlight. PDP phosphors, nitro-cellulose and n-butyl acetate were mixed and coated uniformly in glass tube without stain. The glass tubes were sintered at $550^{\circ}C$ for 20 minutes, vacuumed to $10^{-6}$ torr and supplied discharge gas by using a gas mixture. After various experiment about phosphors thickness and inner diameter of glass tube, the appropriate phosphors thickness and inner diameter of glass tube were obtained. The luminance and luminous efficiency of manufactured fluorescent lamps with Ne+Xe discharge gas were $6,270cd/m^2$, 13 lm/W under 75 kHz sinusoidal wave voltage, respectively.

• Journal of the Korean Society for Advanced Composite Structures
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• v.2 no.1
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• pp.30-39
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• 2011

In this paper, we persent the results of on experimental investigations pertaining to the structural behavior of new type of concrete filled fiber reinforced plastic circular tubes (i.e., hybrid CFFT, HCFFT) which are suggested in order to mitigate the problems associated with the concrete filled steel-concrete composite tube (CFT) and the concrete filled fiber reinforced plastic tube (CFFT). It is found that when the HCFFT is used in the construction of pile foundation the HCFFT pile can transfer axial as well as flexural loads from the superstructure to the underground effectively in comparison with CFT and CFFT piles.

• Archives of Plastic Surgery
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• v.35 no.2
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• pp.134-138
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• 2008

Purpose: In a diabetic foot ulcer, superficial fungal infection of the foot may disrupt the skin integrity and provide an avenue for bacterial infection. The prevalence of fungal infection in diabetic foot ulcer has been reported as 12-30% in Caucasian patients. However, no data are available for Korean patients. The purpose of the study was to examine the prevalence of fungal infection in diabetic foot patients admitted in our clinic. Methods: This study included consecutive 30 diabetic foot ulcer patients(24 males and 6 females) admitted from May 2007 to July 2007. The mean age was 60.5 years. All patients underwent mycological examination including direct microscopic examination in KOH and culturing on slants and tubes with Sabouraud's glucose agar. Results: Clinical signs of presumed fungal infection, which were examined by dermatologists, were found in all patients included in this study. Direct microscopic examination was positive for the specimens of the skin and the toenails in 28(93.3%) and 25(83.3%) patients, respectively. In addition, culture result was positive for the specimens of the skin and the toenails in 5(16.73%) and 7(23.3%) patients, respectively. Conclusion: The prevalence of fungal infection in diabetic foot ulcer patients admitted in our clinic is much higher than that in Caucasian patients(83.3-93.3% vs 12-30%).

• Journal of the Korean Society of Visualization
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• v.10 no.1
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• pp.40-46
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• 2012

Recently micro shock tube is extensively being used in many diverse fields of engineering applications but the detailed flow physics involved in it is hardly known due to high Knudsen number and strong compressibility effects. Unlike the macro shock tube, the surface area to volume ratio for a micro shock tube is very large. This unique effect brings many complexities into the flow physics that makes the micro shock tube different compared with the macro shock tube. In micro shock tube, the inter- molecular forces of working gas can play an important role in specifying the flow characteristics of the unsteady shock wave flow which is essentially generated in all kinds of shock tubes. In the present study, a CFD method was used to predict and visualize the unsteady shock wave flows using the unsteady compressible Navier-Stokes equations, furnished with the no-slip and slip wall boundary conditions. Maxwell's slip equations were used to mathematically model the shock movement at high Knudsen number. The present CFD results show that the propagation speed of the shock wave is directly proportional to the initial pressure and diameter of micro shock tube.

• Toxicological Research
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• v.23 no.3
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• pp.239-244
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• 2007

Respirable particles cause many occupational and environmental diseases of the lung. To study these diseases, laboratory animals are often exposed to these particles. Inhalation and instillation are the well-known techniques for experimental exposures of the lung to respirable particles. Recently, another technique called oropharyngeal aspiration (OPA) has been introduced for exposing the lung to pathogens and/or particles. The conventional OPA technique for the mouse is generally carried out using a micropipette with a fixed slant board. In order to modify the conventional OPA in this study, anesthetized mice were placed on an adjustable slant board, a syringe pump was used to deliver the solution to the oropharynx, and the mice were allowed to recover in vertically positioned tubes for 6 minutes until fully awaked. Most importantly, the whole process of OPA could be carried out simply by an examiner. This modified OPA technique was validated by exposing the mouse lung to Evans Blue dye with a success rate of 95%.

• Parasites, Hosts and Diseases
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• v.47 no.1
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• pp.61-63
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• 2009

Although Toxoplasma gondii infection generally shows subclinical courses in adults, it may have severe pathologic effects on the fetus. For a survey of toxoplasmosis in Shahr-e-Rey area, south of Tehran, Iran, we conducted a serological study on 1,187 general populations using indirect fluorescent antibody (IFA) test. In this cross sectional study, cases were selected randomly by a local primary health care (PHC) system. Blood samples were collected in microcapillary tubes and sera were examined by IFA after centrifugation. It has been shown that 68.3% of cases in all age groups had IFA titer of 1:10 and higher, which we consider as positive cases, and the rate for 1:400 or over was 30.2%. There was meaningful correlation between anti-Toxoplasma antibody titers and age, sex, and occupation of subjected people (P < 0.05%). The incidence was higher in females and highest in the children age group (10-14 years old). The present study demonstrates high prevalence of Toxoplasma infection among the people in south of Tehran, Iran.

• Natural Product Sciences
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• v.10 no.4
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• pp.168-172
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• 2004

In India, Gymnema sylvestre due to the unique property of the plant to antagonize the sweet taste is known as 'Gur-mar'. It has several ethnomedicinal values as various tribals/traditional communities and rural peoples of India find diverse medicinal uses viz. antidiabetic, stomachic, diuretic, and is useful in cough and throat troubles. Besides, it has strong effect on reducing blood sugar. The present communication deals with the detailed pharmacognostical evaluation of the aerial parts of G. sylvestre collected from three places of the country-Varanasi (U.P), Panchmarhi (M.P), Salem (Tami Nadu) and commercial sample procured from local market. The botanical and physico-chemical parameters of all the samples were quite similar though little variations were observed in foaming index, alcohol and water soluble extractives of local sample. The microscopic characteristics of the drug are horse shoe shaped petiole with 3 amphicribal vascular bundles, sieve tubes well developed; anomocytic stomata only on the abaxial surface of the leaf, the fan shaped amphicribal vascular bundle, presence of intraxylary phloem. The TLC fingerprint profile of all the samples was more or less similar only the quantity of some of the compounds varied.

• The Plant Pathology Journal
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• v.18 no.3
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• pp.161-164
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• 2002

Colletotrichum musae was isolated from dark-brown anthracnose lesions on commercial banana (Musa sapientum L.) to establish the causal agent of the symptom. The fungus grew fast and produced white aerial mycelium on PDA. Acervuli developed abundantly on culture plates after incubation for 10 days at $25^{\circ}C$. Pinkish conidial masses were produced on the acervuli, which mostly coalesced together, Conidia were aseptate, hyaline, straight, ellipsoid to globose, and 14.5$\times$6.9 $\mu\textrm{m}$ in size. Black, clavate, round, or irregular-shaped appressoria measuring 8.8$\times$6.8 $\mu\textrm{m}$ were readily formed from germ tubes. Setae-like structures were not found either on the lesion or on the cultures. Sclerotia were also absent. Among the media, PDA medium was the best for mycelial growth. The optimum temperature for mycelial growth was $28^{\circ}C$, while the optimum pH ranged from pH 5.5 to 6.5. The isolates of C musae caused black necrotic lesions on banana fruits by needle-wound inoculation, and orange-colored spore masses were produced on the lesions. The fungus also caused discoloration on apple fruits inoculated.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.1
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• pp.45-54
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• 2002

The breakup phenomena of a vertical laminar jet issuing from capillary tubes in a quiescent ambient air are investigated using a forced vibration analysis of the surface wave. Using a linear approach to the transient jet velocity, an approximate solution fur the longitudinal motion of a vertical liquid jet is theoretically derived, thus performing an instability analysis by a vibration method. The damping term of this equation is nonlinear as it depends on dimensionless parameters, a Weber number, and an Ohnesorge number. The instability condition is determined based on whether the coefficient of the damping term is less than zero or not. Uniform drop formation is dependent on the vibration frequency fur the forced vibration case.