• Geomechanics and Engineering
• /
• v.14 no.6
• /
• pp.533-544
• /
• 2018

The importance of using materials cost effectively to enhance the strength and reduce the cost, and weight of earth fill materials in geotechnical engineering led researchers to seek for modifying the soil properties by adding proper additives. Lightweight fill materials made of soil, binder, water, and Expanded polystyrene (EPS) beads are increasingly being used in geotechnical practices. This paper primarily investigates the behavior of sandy soil, modified by EPS particles. Besides, the mechanical properties of blending sand, EPS and the binder material such as fly ash and cement were examined in different mixing ratios using a number of various laboratory studies including the Modified Standard Proctor (MSP) test, the Unconfined Compressive Strength (UCS) test, the California Bearing Ratio (CBR) test and the Direct Shear test (DST). According to the results, an increase of 0.1% of EPS results in a reduction of the density of the mixture for 10%, as well as making the mixture more ductile rather than brittle. Moreover, the compressive strength, CBR value and shear strength parameters of the mixture decreases by an increase of the EPS beads, a trend on the contrary to the increase of cement and fly ash content.

• Food Science and Biotechnology
• /
• v.17 no.5
• /
• pp.1038-1046
• /
• 2008

This study was carried out to develop a small-sized biosensor based on surface plasmon resonance (SPR) for the rapid identification of insecticide residues for food safety. The SPR biosensor module consists of a single 770 nm-light emitting diodes (LED) light source, several optical lenses for transferring light, a hemisphere sensor chip, photo detector, A/D converter, power source, and software for signal processing using a computer. Except for the computer, the size and weight of the sensor module are 150 (L)$\times$70 (W)$\times$120 (H) mm and 828 g, respectively. Validation and application procedures were designed to assess refractive index analysis, affinity properties, sensitivity, linearity, limits of detection, and robustness which includes an analysis of baseline stability and reproducibility of ligand immobilization using carbamate (carbofuran and carbaryl) and organophosphate (cadusafos, ethoprofos, and chlorpyrifos) insecticide residues. With direct binding analysis, insecticide residues were detected at less than the minimum 0.01 ppm and analyzed in less than 100 sec with a good linear relationship. Based on these results, we find that the binding interaction with active target groups in enzymes using the miniaturized SPR biosensor could detect low concentrations which satisfy the maximum residue limits for pesticide tolerance in Korea, Japan, and the USA.

• Korean Journal of Child Studies
• /
• v.35 no.4
• /
• pp.179-198
• /
• 2014

The main purpose of this study was to examine direct and indirect effects of mothers' depression on preschoolers' externalizing problem behaviors. A total of 155 mothers with preschoolers aged 3 and 4 years (83 boys and 72 girls) living in Seoul participated in this study. Mothers completed questionnaires on mothers' depression, parenting behavior, and preschoolers' externalizing problem behaviors. Direct and indirect pathways from mothers' depression to preschoolers' externalizing problem behaviors were analyzed using Structural Equation Modeling (SEM). First, it was revealed that mothers' depression did not directly affect preschoolers' externalizing problem behaviors. Second, mothers' depression indirectly influenced preschoolers' externalizing problem behaviors through mothers' parenting behavior. Mothers who reported higher levels of depression showed less warmth/acceptance and more rejection/restriction towards their children, which led to higher levels of preschoolers' externalizing problem behaviors. These findings emphasize the importance of positive parenting by mothers in reducing preschoolers' problem behaviors.

• Journal of Animal Science and Technology
• /
• v.45 no.5
• /
• pp.725-730
• /
• 2003

This study was conducted to evaluate the adequacy of an alternative a.m.-p.m. testing scheme for milk yield in comparison with the official test method based on weighing two milkings within 24 h. A total of 8,309 p.m. milking weights and 6,767 a.m. milking weights from 72 Holstein cows raised at N.L.R.I. were collected between October 2000 and November 2001. Ratios were computes for daily milk yield to a.m. and p.m. milking weights(direct yield ratios) and ratios of a.m. and p.m. milking weights to daily milk yield (inverse yield ratios). Analysis of variance indicated that the milking interval is the most important source of variation for yield ratios. Adjustment factors for estimating daily milk yield from single milking weights were derived through regression analysis of direct and inverse yield ratios on the length of the milking interval. Daily milk yield was estimated more precisely and accurately when adjustment factors were used than when single milking weights were doubled. In conclusion, alternative recording of a.m. and p.m. milking weights led to reliable estimates of milk yields.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.2
• /
• pp.304-315
• /
• 2013

In this paper, analysis of cascaded H-bridge multilevel inverter in DTC-SVM (Direct Torque Control-Space Vector Modulation) based induction motor drive for FCEV (Fuel Cell Electric Vehicle) is presented. Cascaded H-bridge multilevel inverter uses multiple series units of H-bridge power cells to achieve medium-voltage operation and low harmonic distortion. In FCEV, a fuel cell stack is used as the major source of electric power moreover the battery and/or ultra-capacitor is used to assist the fuel cell. These sources are suitable for utilizing in cascaded H-bridge multilevel inverter. The drive control strategy is based on DTC-SVM technique. In this scheme, first, stator voltage vector is calculated and then realized by SVM method. Contribution of multilevel inverter to the DTC-SVM scheme is led to achieve high performance motor drive. Simulations are carried out in Matlab-Simulink. Five-level and nine-level inverters are applied in 3hp FCEV induction motor drive for analysis the multilevel inverter. Each H-bridge is implemented using one fuel cell and battery. Good dynamic control and low ripple in the torque and the flux as well as distortion decrease in voltage and current profiles, demonstrate the great performance of multilevel inverter in DTC-SVM induction motor drive for vehicle application.

• Biomedical Science Letters
• /
• v.25 no.4
• /
• pp.293-301
• /
• 2019

Combination chemotherapy is more effective than mono-chemotherapy and is widely used in clinical practice for enhanced cancer treatment. In this study, we investigated the potential synergistic effects of acetaminophen, a common component in many cold medicines, and romidepsin, a histone deacetylase (HDAC) inhibitor, in the A549 non-small cell lung cancer (NSCLC) cell line. The combination of acetaminophen and romidepsin also exerted significant cytotoxicity and apoptosis induced by activation of caspase-3 on tumor cells in vitro. Moreover, combination therapy significantly induced increased production of chemokines that stimulate migration of activated T-cells into tumor cells. This mechanism can lead to active T-cell mediated anti-tumor immunity in addition to the direct cytotoxic chemotherapeutic effect. Activated T-cells led to enhanced cytotoxicity in drug-treated A549 cells through interaction with tumor cells. These results suggested that the interaction between the two drugs is synergistic and significant. In conclusion, our data showed that the use of romidepsin and low concentrations acetaminophen could induce effective anti-tumor effects via enhanced tumor immune and direct cytotoxic chemotherapeutic responses. The combination of acetaminophen with romidepsin should be considered as a promising strategy for the treatment of lung cancer.

• Journal of Chest Surgery
• /
• v.31 no.9
• /
• pp.899-902
• /
• 1998

Recent advances in understanding the anatomy of complete atrioventricular septal defect have led to alternative methods of repairing these defects. Here we report two cases of complete atrioventricular septal defect repair by direct closure of the ventricular element of the defect. Follow-up for average of 3 months suggests that, when direct closure can be performed, the results can be comparable with those of the standard technique. Our initial success with this approach is encouraging; however, longer follow-up and more experiences are required to establish whether it will be broadly applicable.

• Land and Housing Review
• /
• v.5 no.4
• /
• pp.281-290
• /
• 2014

This comparative analysis on the project scheme of property-led regeneration of UK and Japan aimed to suggest the implications for economy-based urban regeneration of Korea. Property-led regeneration attract private capital by deregulation and public investment since 1980s' neoliberalism. Its effectiveness for creating job and economic growth is demonstrated through last decades. The cases of property-led urban regeneration of 2000s, such as Stratford, King's Cross, Otemach and Shinonome, show decrease of public direct investment, promoting deregulation. It also proved that property-led urban regeneration has a great ripple effect to local economy. And the partnership among central and local governments, public development corporations, private developers and other local interest groups is emphasized for delivering successful urban regeneration. Especially, human empowerment of local government and responsibility of public organization are also required to deliver urban regeneration.

• Restorative Dentistry and Endodontics
• /
• v.35 no.5
• /
• pp.353-358
• /
• 2010

Objectives: The purpose of this study was to measure the power density of light curing units transmitted through resin inlays fabricated with direct composite (Filtek Z350, Filtek Supreme XT) and indirect composite (Sinfony). Materials and Methods: A3 shade of Z350, A3B and A3E shades of Supreme XT, and A3, E3, and T1 shades of Sinfony were used to fabricate the resin inlays in 1.5 mm thickness. The power density of a halogen light curing unit (Optilux 360) and an LED light curing unit (Elipar S10) through the fabricated resin inlays was measured with a hand held dental radiometer (Cure Rite). To investigate the effect of each composite layer consisting the resin inlays on light transmission, resin specimens of each shade were fabricated in 0.5 mm thickness and power density was measured through the resin specimens. Results: The power density through the resin inlays was lowest with the Z350 A3, followed by Supreme XT A3B and A3E. The power density was highest with Sinfony A3, E3, and T1 (p < 0.05). The power density through 0.5 mm thick resin specimens was lowest with dentin shades, Sinfony A3, Z350 A3, Supreme XT A3B, followed by enamel shades, Supreme XT A3E and Sinfony E3. The power density was highest with translucent shade, Sinfony T1 (p < 0.05). Conclusions: Using indirect lab composites with dentin, enamel, and translucent shades rather than direct composites with one or two shades could be advantageous in transmitting curing lights through resin inlays.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.15 no.6
• /
• pp.479-485
• /
• 2002

We have investigated the effects of various wafers cleaning on glass/Si bonding using 4 inch Pyrex glass wafers and 4 inch silicon wafers. The various wafer cleaning methods were examined; SPM(sulfuric-peroxide mixture, $H_2SO_4:H_2O_2$ = 4 : 1, $120^{\circ}C$), RCA(company name, $NH_4OH:H_2O_2:H_2O$ = 1 : 1 : 5, $80^{\circ}C$), and combinations of those. The best room temperature bonding result was achieved when wafers were cleaned by SPM followed by RCA cleaning. The minimum increase in surface roughness measured by AFM(atomic force microscope) confirmed such results. During successive heat treatments, the bonding strength was improved with increased annealing temperatures up to $400^{\circ}C$, but debonding was observed at $450^{\circ}C$. The difference in thermal expansion coefficients between glass and Si wafer led debonding. When annealed at fixed temperatures(300 and $400^{\circ}C$), bonding strength was enhanced until 28 hours, but then decreased for further anneal. To find the cause of decrease in bonding strength in excessively long annealing time, the ion distribution at Si surface was investigated using SIMS(secondary ion mass spectrometry). tons such as sodium, which had been existed only in glass before annealing, were found at Si surface for long annealed samples. Decrease in bonding strength can be caused by the diffused sodium ions to pass the glass/si interface. Therefore, maximum bonding strength can be achieved when the cleaning procedure and the ion concentrations at interface are optimized in glass/Si wafer direct bonding.