Construction of Inchon International Airport

To face with the increasing the air transportation in Korea, the construction of Inchon International Airport is underway in the bay of Inchon on the reclaimed land. The construction project has begun since the end of 1992, and will be completed by the end of year 2000. This paper presents the general plan of project, site development, soil improvement work, transportation system, and construction budget and fund

Uniform Hazard Response Spectra of Korea Considering Uncertainties in Ground Properties

The seismic site coefficients derived deterministically are often used with ground motion parameters determined by probabilistic seismic hazard analysis in construction of the design response spectrum. There is, therefore, an inherent incompatibility between two approaches. New methods have been developed to resolve this incompatibility by developing probabilistic seismic site coefficients. In such approaches, the uncertainties in the properties of the ground were not systematically accounted for due to lack of measurements of the ground. In this study, an integrated probabilistic seismic hazard analysis which can quantify the nonlinear seismic site effects and account for the uncertainties in soil properties is developed and used to generate the uniform hazard response spectra in Korea. The procedure used an extensive database of measured shear wave velocity profiles and dynamic curves, which included more than 114 shear wave velocity profiles and more than 15 dynamic curves. The calculated uniform hazard response spectra were compared to the design spectra. Comparisons show significant discrepancy between two spectra, and highlight the need to revise the current design guideline

A Case Study of Characteristics of Damages Caused by Typhoon EWINIAR 2006 in South Korea

During recent years, the climate of Korea has clearly been divided between dry season and rainy season due to the global warming and other reasons, and a record breaking rain is falling every year. The mountain slopes in Korea receives significant damage generally during the seasons of high rain front and typhoon. In 2006, the rainy season started in July and Typhoon EWINIAR which hit South Korea between July 26 and 28 caused significant damage to various slopes and roads. This paper presents a case study of the damages and characteristics of the damages to cut slopes, fill slopes, and roads caused by the concentrated heavy rains for 3 days in the regions of Inje and YangYang

A Case Study on Safe Blast Design with Vibration Analysis

Safe delicacy blasting is necessarily to decrease safe problems resulting from blasting but if designs to consider only safety, it is a problem not to ensure economical gains because the effect of blasting is decreased. Therefore, blasting vibration must be predicted to consider given circumstances and ground conditions before blasting work, and then a design based on predicted result must be done. In this study, the testing blasting was carried out in two fields within a country, and then measured data for testing blasting were collected. The effect for blasting vibration was analyzed as the property of distance, charging gunpowder capacity, surrounding conditions, and measured points. The test results were performed by back-analysis, and compared with previous research results. Therefore, it will be proposed an effective prediction and design

Dynamic Loading Induced Settlement of Strip Foundation on Geogrid-Reinforced Clay

Laboratory model tests to determine the load. The variation of the maximum permanent supported by geogrid-reinforced saturated clay and subjected to a low-frequency cyclic load are presented. In conducting the test, the foundation was initially subjected to an allowable static load. The cyclic load was then super-imposed over the static permanent settlement of a surface strip foundation settlement with the intensity of the static load and the intensity of the amplitude of the cyclic load are also presented

Effet d'un agitateur mécanique sur l'hydrodynamique et le transfert de matière gaz—liquide en réacteur gazosiphon

Cette étude expérimentale décrit l'effet d'un agitateur sur l'hydrodynamique et le transfert de matière à l'intérieur d'un contacteur airlift à boucle interne. La contribution des deux éléments moteurs (gaz et agitateur) est identifiée. Suivant les conditions de fonctionnement, ou bien ces deux effets s'ajoutent et favorisent la circulation du liquide ou bien ces effets sont opposés, la vitesse du liquide est alors réduite. Par contre, en ce qui concerne le transfert gaz—liquide, l'utilisation de l'agitateur est bénéfique puisque, pour certaines conditions opératoires, le coefficient de transfert est multiplié par 4 par rapport à celui obtenu sans agitation. L'analyse des diverses contributions énergétiques dans l'appareil montre que la présence de l'agitateur est justifiée uniquement dans les cas où le débit de gaz doit rester faible

Effect of few-walled carbon nanotube crystallinity on electron field emission property

We discuss the influence of few-walled carbon nanotubes (FWCNTs) treated with nitric acid and/or sulfuric acid on field emission characteristics. FWCNTs/tetraethyl orthosilicate (TEOS) thin film field emitters were fabricated by a spray method using FWCNTs/TEOS sol one-component solution onto indium tin oxide (ITO) glass. After thermal curing, they were found tightly adhered to the ITO glass, and after an activation process by a taping method, numerous FWCNTs were aligned preferentially in the vertical direction. Pristine FWCNT/ TEOS-based field emitters revealed higher current density, lower turn-on field, and a higher field enhancement factor than the oxidized FWCNTs-based field emitters. However, the unstable dispersion of pristine FWCNT in TEOS/N,N-dimethylformamide solution was not applicable to the field emitter fabrication using a spray method. Although the field emitter of nitric acid-treated FWCNT showed slightly lower field emission characteristics, this could be improved by the introduction of metal nanoparticles or resistive layer coating. Thus, we can conclude that our spray method using nitric acid-treated FWCNT could be useful for fabricating a field emitter and offers several advantages compared to previously reported techniques such as chemical vapor deposition and screen printing.ope

Antitumorigenic effect of atmospheric-pressure dielectric barrier discharge on human colorectal cancer cells via regulation of Sp1 transcription factor

Human colorectal cancer cell lines (HT29 and HCT116) were exposed to dielectric barrier discharge (DBD) plasma at atmospheric pressure to investigate the anticancer capacity of the plasma. The dose- and time-dependent effects of DBDP on cell viability, regulation of transcription factor Sp1, cell-cycle analysis, and colony formation were investigated by means of MTS assay, DAPI staining, propidium iodide staining, annexin V-FITC staining, Western blot analysis, RT-PCR analysis, fluorescence microscopy, and anchorage-independent cell transformation assay. By increasing the duration of plasma dose times, significant reductions in the levels of both Sp1 protein and Sp1 mRNA were observed in both cell lines. Also, expression of negative regulators related to the cell cycle (such as p53, p21, and p27) was increased and of the positive regulator cyclin D1 was decreased, indicating that the plasma treatment led to apoptosis and cell-cycle arrest. In addition, the sizes and quantities of colony formation were significantly suppressed even though two cancer promoters, such as TPA and epidermal growth factor, accompanied the plasma treatment. Thus, plasma treatment inhibited cell viability and colony formation by suppressing Sp1, which induced apoptosis and cell-cycle arrest in these two human colorectal cancer cell lines.1

Inhibitory Effect of Inflexinol on Nitric Oxide Generation and iNOS Expression via Inhibition of NF-κB Activation

Inflexinol, an ent-kaurane diterpenoid, was isolated from the leaves of Isodon excisus. Many diterpenoids isolated from the genus Isodon (Labiatae) have antitumor and antiinflammatory activities. We investigated the antiinflammatory effect of inflexinol in RAW 264.7 cells and astrocytes. As a result, we found that inflexinol (1, 5, 10 μM) suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) as well as the production of nitric oxide (NO) in LPS-stimulated RAW 264.7 cells and astrocytes. Consistent with the inhibitory effect on iNOS and COX-2 expression, inflexinol also inhibited transcriptional and DNA binding activity of NF-κB via inhibition of IκB degradation as well as p50 and p65 translocation into nucleus. These results suggest that inflexinol inhibits iNOS and COX-2 expression through inhibition of NF-κB activation, thereby inhibits generation of inflammatory mediators in RAW 264.7 cells and astrocytes, and may be useful for treatment of inflammatory diseases

Characterization of the antimicrobial substances produced by Nibribacter radioresistens

This study characterized the antimicrobial substances produced by the radiation-resistant bacterium Nibribacter radioresistens. The antimicrobial substances showed activity against Salmonella Gallinarum, pathogenic Escherichia coli, Bacillus cereus, Streptococcus iniae, and Saccharomyces cerevisiae. The substances showed higher activity against Gram-positive bacteria than against Gram-negative bacteria and yeast. N. radioresistens showed the best growth rate in LB liquid medium at 37ºC; however, production of the antimicrobial substances was not associated with growth. Since the activity of the antimicrobial substances was affected by proteinase K and EDTA, the substances were presumed to be antimicrobial peptides (AMPs). The antimicrobial substances produced by N. radioresistens were unstable at higher temperatures and in acidic and basic pH ranges, and most of the activity was attributed to either low (30 kDa) molecules. When S. Gallinarum was treated with the antimicrobial substances, the cell destruction was acted on the cell envelope. Therefore, we concluded that N. radioresistens produces broad-spectrum and very unstable antimicrobial substances that mostly consist of low- and high-molecular weight peptides