• International Journal of Highway Engineering
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• v.18 no.1
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• pp.63-72
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• 2016

PURPOSES : The use of roller-compacted concrete pavement (RCCP) is an environmentally friendly method of construction that utilizes the aggregate interlock effect by means of a hydration reaction and roller compacting, demonstrating a superb structural performance with a relatively small unit water content and unit cement content. However, even if an excellent structural performance was secured through a previous study, the verification research on the environmental load and long-term durability was conducted under unsatisfactory conditions. In order to secure longterm durability, the construction of an appropriate internal air-void structure is required. In this study, a method of improving the long-term durability of RCCP will be suggested by analyzing the internal air-void structure and relevant durability of roller-compacted concrete. METHODS : The method of improving the long-term durability involves measurements of the air content, air voids, and air-spacing factor in RCCP that experiences a change in terms of the kind of air-entraining agent and chemical admixture proportions. This test should be conducted on the basis of test criteria such as ASTM C 457, 672, and KS F 2456. RESULTS : Freezing, thawing, and scaling resistance tests of roller compacted concrete without a chemical admixture showed that it was weak. However, as a result of conducting air entraining (AE) with an AE agent, a large amount of air was distributed with a range of 2~3%, and an air void spacing factor ranging from 200 to $300{\mu}m$ (close to $250{\mu}m$) coming from PCA was secured. Accordingly, the freezing and thawing resistance was improved, with a relative dynamic elastic modulus of more than 80%, and the scaling resistance was improved under the appropriate AE agent content rate. CONCLUSIONS : The long-term durability of RCCP has a direct relationship with the air-void spacing factor, and it can be secured only by ensuring the air void spacing factor through air entraining with the inclusion of an AE agent.

• Tuberculosis and Respiratory Diseases
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• v.48 no.5
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• pp.730-739
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• 2000

Background : The aim of this study was to analyze the clinical manifestations and efficacy of treatment regimens in order to determine the adequate combination of anti-tuberculotic agents and duration of treatment for tuberculous lymphadenitis. Methods : We made a review of 373 patients with tuberculous lymphadenitis, who were admitted to four medical college hospitals in Taegu Korea from 1989 to 1998, and their diagnoses were confirmed histologically and bacteriologically. Results : The incidence of tuberculous lymphadenitis was 71.3% in women and 57.7% were between the ages of 20 and 39 years. The most common symptom was painless swelling. The most commonly involved lymph nodes were unilateral superficial cervical lymph node groups. Tuberculous lymphadenitis was accompanied with active pulmonary tuberculosis, commonly. The sensitivity of fine needle aspiration(FNA) in tuberculous lymphadenitis was 79.6%, and 92.2% of the patients had a strong positive reaction to the tuberculin skin test. The most commonly prescribed anti-tuberculotic regimen was the combination of INH, RMP, EMB, and PZA(62.6 %). Eighty percent of patient were treated for 9-12 months. There was no significantly difference in the recurrence rate of tuberculous lymphadenitis between the combinations of anti-tuberculotic agent, including INH and RMP, and between the durations of treatment, for a period of 6 months of more. Conclusion : The combination of FNA cytologic examination and tuberculin skin test may be helpful in the diagnosis of tuberculous lymphadenitis. We propose that the combination of anti-tuberculotic agents, INH, RMP, EMB, and PZA, be prescribed to patients for 6 to 9 months.

• Toxicological Research
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• v.29 no.3
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• pp.203-209
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• 2013

A simple and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of ${\varepsilon}$-acetamidocaproic acid (AACA), the primary metabolite of zinc acexamate (ZAC), in rat plasma by using normetanephrine as an internal standard. Sample preparation involved protein precipitation using methanol. Separation was achieved on a Gemini-NX $C_{18}$ column ($150mm{\times}2.0mm$, i.d., 3 ${\mu}m$ particle size) using a mixture of 0.1% formic acid-water : acetonitrile (80 : 20, v/v) as the mobile phase at a flow rate of 200 ${\mu}l/min$. Quantification was performed on a triple quadrupole mass spectrometer employing electrospray ionization and operating in multiple reaction monitoring (MRM) and positive ion mode. The total chromatographic run time was 4.0 min, and the calibration curves of AACA were linear over the concentration range of 20~5000 ng/ml in rat plasma. The coefficient of variation and relative error at four QC levels were ranged from 1.0% to 5.8% and from -8.4% to 6.6%, respectively. The present method was successfully applied for estimating the pharmacokinetic parameters of AACA following intravenous or oral administration of ZAC to rats.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.720-722
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• 2009

This work is mainly focused at developing the hydrogen production unit with the capacity of 20 $Nm^3/h$ of high purity hydrogen. At present steam reforming of natural gas is the preferable method to produce hydrogen at the point of production cost. The developed hydrogen production unit composed of natural gas reformer and pressure swing adsorption system. To improve the thermal efficiency of steam reforming reactor, the internal heat recuperating structure was adopted. The heat contained in reformed gas which comes out of the catalytic beds recovered by reaction feed stream. These features of design reduce the fuel consumption into burner and the heat duty of external heat exchangers, such as feed pre-heater and steam generator. The production rate of natural gas reformer was 41.7 $Nm^3/h$ as a dryreformate basis. The composition of PSA feed gas was $H_2$ 78.26%, $CO_2$ 18.49%, CO 1.43% and $CH_4$ 1.85%. The integrated production unit can produce 21.1 $Nm^3/h$ of high-purity hydrogen (99.997%). The hydrogen production efficiency of the developed unit was more than 58% as an LHV basis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.2
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• pp.219-221
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• 2017

In 2015, white cottony tufts were observed on gametophytes of the kelp Saccharina japonica. Wet mount and histopathology examination revealed numerous fungal hyphae and mycelium around the gametophytes. The gametophytes surrounded by fungal hyphae were generally round and empty. A specific 610-bp fragment of the internal transcribed spacer (ITS)-5.8S rDNA-ITS gene of fungi was amplified by polymerase chain reaction and the nucleotide sequence showed 100% identity with those of Acremonium sclerotigenum, Acremonium sp. and Ascomycota sp. When fungus-infected gametophytes were mixed with healthy gametophytes, a high transmission rate (100%) resulted. This is the first report of mycosis of gametophytes in Korea.

• Nuclear Engineering and Technology
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• v.20 no.1
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• pp.54-64
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• 1988

This paper assesses the models in the SCDAP code using the results of the FLHT-2 test. Calculations show that the SCDAP correctly predicts Ire temperatures, oxidation front movement, overall hydrogen generation and peak generation rate, internal fuel rod pressure, and cladding rupture due to ballooning. A comparison of the calculated results with measured data shows that two phase level is underpredicted, and that radiation heat transfer and auto-catalytic reaction temperature of zircaloy are overpredicted. These models are recommended to be modified. The analysis also shows that the simulation of the gap in a fuel rod improves the code prediction on core damage progression.

• Journal of the Korean Ceramic Society
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• v.31 no.5
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• pp.552-560
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• 1994

A composite of TiB2-Al2O3 system was successfully prepared from a mixture of TiO2, B2O3, and Al by self-propagating high temperature synthesis (SHS) with a novel characteristic, utilizing the internal oxidation heat of aluminium metal of the mixture, instead of by a conventional technique, externally heating a mixture of Ti, B and Al2O3. From a mixture with B/Ti molar ratio of =2.0, pure two phases of TiB2 and $\alpha$-Al2O3 with good crystallinity and small, uniform sizes were formed. However, when the B/Ti molar ratio of the mixture goes to a value less than 2.0, in addition to the above main minerals, a small smounts of metastable phases such as TiB and Ti3B4 were formed. It was found that about 60%, the optimum green density of compacts gave their highest reaction rate and temperature during SHS process. TiB2-Al2O3 system composite with B/Ti molar ratio of =2.0 could be pressurelessly sintered even at 190$0^{\circ}C$ under Ar gas flows without any addition of sintering aids, showing their good properties such as 91.2% in relative density, 2750 kgf/$\textrm{mm}^2$ in Vickers hardness and 2620 kgf/$\textrm{cm}^2$ in flexural strength.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3191-3193
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• 2016

Background: The human papilloma virus (HPV) is considered as the major risk factor for the development of cervical cancer. This virus is of different genotypes and generally can be classified into high and low risk types. Objective: To determine the rate of high risk HPV genotypes in women with vaginal discharge and lower abdominal pain in Kurdistan region, Iraq. Materials and Methods: Cervical swabs were taken from 104 women. DNA was extracted and the polymerase chain reaction (PCR) technique was used to determine the presence of high risk genotypes. Results: It was found that 13/104 (12.5%) of the samples were positive for high risk HPV genotypes. Amongst those who were positive, 4/13 (30.7%) were typed as genotype 16 and 7/13 (53.8%) showed mixed genotyping. On the other hand, genotypes 53 and 56 were found in only one sample each. Conclusions: High risk HPV genotypes are not uncommon and further community based study is needed to determine the prevalence of HPV and its genotypes and plan for prevention of infection.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.3
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• pp.632-638
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• 2007

Pyrolysis experiments of HDPE and LDPE were carried out in the stainless steel reactor of internal volume of 40 $cm^3$. Pyrolysis reactions were performed at temperature $410{\sim}460^{\circ}C$ and the pyrolysis products were collected separately as liquid and gas products. The molecular weight distributions(MWDs) and composition of each product were determined by HPLC-GPC and GC analysis. It was represented that the yield and the molecular weight of liquid product were decreased with the increase of reaction temperature and time. The chain-end scission rate parameters, respectively, were determined to be 63.0kcal/mole of HDPE, 45.7kcal/mole of LDPE by the Arrhenius plot.

• Journal of environmental and Sanitary engineering
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• v.13 no.1
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• pp.91-103
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• 1998

Design data for COD and nitrogen removal from wastewater were collected from Pilot's Multi-stage Bio-reactor. Hyraulic conditions and pollutant loadings were varied in order to optimize the biological and operational parameters. Pilot's experimental results summarize as followings. 1. T-N removal efficiency in the organic volumetric loading 0.2 kgCOD/m$^{3}$·d was obtained as maxium of 85% at internal recycle ratio 2.5 and in more ratio than this it was decreased. Organic removal efficiency was about 91% under the overall experimental conditions and not influenced by recycle ratio.. 2. Nitrification reaction was shown as maxium in the SCOD$_{cr}$/NH$^{+}$-N ratio of 6.5 and in more ratio than this it was decreased. Denitrification rate was the maxium as 85% in more than 7.5 of SCOD$_{cr}$/NO$_{x}$-N ratio and in the ratio over this ratio it becomes constant. 3. By utilizing an applied new model of Stover-Kincannon from Monod's kinetic model, concentration of T-N in the effluent according to flow quanity in the influent was estimated as 8.74 and -67.5 respectively. The formula for estimating T-N concentration of effluent was obtained like this: N$_e$=N$_0$(1- $\frac{8.74}{(QN$_0$/A)-67.05}$)