• Journal of the Korean Institute of Gas
• /
• v.24 no.1
• /
• pp.10-16
• /
• 2020

In the safety control and business of liquefied petroleum gas act, LPG supply using bulk lorry of liquefied petroleum gas dealer is possible only to small storage tanks of less than 3 tons in bulk lorry less 10 tons. The government has announced plans to extend the bulk lorry supply to storage tanks of less than 10 tons, reflecting improved safety management capabilities of liquefied petroleum gas dealer. Therefore, in order to supply LPG to the storage tank stably through the bulk lorry, the technical evaluation of the existing bulk lorry LPG supply system is needed. In this study, we will investigate the status of LPG supply system in Korea through bulk lorry and investigate safe LPG supply method. First, we conducted a survey on the supply of LPG storage tanks through bulk lorry to related companies to collect basic data. Based on the results of the surveys, we will conduct field surveys to provide basic data for stable LPG supply.

• Journal of Korean Society for Atmospheric Environment
• /
• v.15 no.5
• /
• pp.667-676
• /
• 1999

The roles of ceria on three-way catalyst is to improve the noble metal dispersion and thermal stability of support ${\gamma}$-$Al_2O_3$. And, ceria has a oxygen storage capacity(OSC) under fuel rich/lean conditions to improve the operating windows of NOx, THC and CO conversion. However, ceria has weak thermal stability under high temperature due to the crystallite growth. So that, the OSC of ceria is decreased, and then the conversions of NOx, THC and CO is decreased. One way of enhancing the thermal stability and NOx, THC and CO conversion Pd-only catalyst is to improve as well as its thermal stability and oxygen storage capacity of the ceria. Especially, the appropriate mixing ratios of bulk and stabilized ceria are very important for designing principles of Pd-only three-way catalysts. In this paper, we discussed the thermal properties of stabilizedand unstabilized (bulk) ceria, and the oxygen storage capacity (OSC) of catalysts, and found the correlation between activity and the OSC of Pd-only catalysts with various different mixing ratios of bulk and stabilized ceria. Finally, we propose the design principles to improve the thermal stability of washcoated Pd-only catalysts.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2011.06a
• /
• pp.1197-1198
• /
• 2011

• Proceedings of the Korea Water Resources Association Conference
• /
• 2023.05a
• /
• pp.167-167
• /
• 2023

Soil organic carbon (SOC) is a critical component of soil health and is crucial in mitigating climate change by sequestering carbon from the atmosphere. Accurate estimation of SOC storage is essential for understanding SOC dynamics and developing effective soil management strategies. This study aimed to investigate the factors influencing the spatial distribution of SOC storage in South Korea, using bulk density (BD) prediction to estimate SOC stock. The study utilized data from 393 soil series collected from various land uses across South Korea established by Korea Rural Development Administration from 1968-1999. The samples were analyzed for soil properties such as soil texture, pH, and BD, and SOC stock was estimated using a predictive model based on BD. The average SOC stock in South Korea at 30 cm topsoil was 49.1 Mg/ha. The study results revealed that soil texture and land use were the most significant factors influencing the spatial distribution of SOC storage in South Korea. Forested areas had significantly higher SOC storage than other land use types. Climate variables such as temperature and precipitation had a relative influence on SOC storage. The findings of this study provide valuable insights into the factors influencing the spatial distribution of SOC storage in South Korea.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2001.06a
• /
• pp.118-118
• /
• 2001

• Journal of the korean academy of Pediatric Dentistry
• /
• v.46 no.4
• /
• pp.353-361
• /
• 2019

The aim of this study was to evaluate the color stability of bulk-fill and conventional resin composites with respect to different storage media and thickness of composites. Filtek™ Z250 and Filtek™ Z350XT were evaluated as conventional resin composites. Filtek™ Bulk-fill Posterior Restorative and Tetric^® N-Ceram Bulk Fill were evaluated as bulk-fill resin composites. CIE L^*a^*b^* values of baseline were measured after 24 hours of storage in distilled water, and each resin composite group was divided into three subgroups and stored in distilled water, red wine, and coffee media respectively. Again after 1, 7 and 28 days of immersion, color changes (ΔE^*) were calculated using the CIE L^*a^*b^* values. The greatest ΔE^* was observed in red wine for all resin composites, and the mean color changes were ranked in the increasing order of distilled water, coffee, red wine. Filtek™ Z350XT exhibited the greatest color change in all media, followed by Filtek™ Bulk-fill Posterior Restorative. Filtek™ Z250 and Tetric^® N-Ceram Bulk Fill followed with similar mean color change values. According to the 2 different thicknesses of 2 mm and 4 mm of bulk-fill resin composites, there was no thickness-related difference on color changes.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2015.05a
• /
• pp.53-54
• /
• 2015

• Transactions of the Society of Information Storage Systems
• /
• v.1 no.2
• /
• pp.175-181
• /
• 2005

SiOB is an essential part of slim optical pickup, where the silicon mirror, LD stand, silicon PD are integrated and LD is flip chip bonded. SiOB is fabricated with bulk micromachining. Especially the fabrication of silicon wafer with stepped concave areas has many extraordinary difficulties. As a matter of fact, experiences and knowledges are rare in the fabrication of the highly stepped silicon wafer. The difficulties occurring in the integration of PD and SiOB, and highly stepped patterning, and silicon mirror roughness and how-to-solve will be discussed.

• Journal of Biosystems Engineering
• /
• v.20 no.2
• /
• pp.151-161
• /
• 1995

A basic proposal on the design of a grain drying and storage system was suggested for the bulk facilities of grain custody warehouses. A model square silo system was designed and developed on the basis of the proposal. A square silo system made of steel plate was developed with a stirring device, an automatic moisture meter and an auto-control system of PLC. Then, the developed square silo system was evaluated through drying experiments with rough rice. The square silo system could dry grains uniformly with a stirring device and an auto-control system regardless of grain depth. The developed square silo system can be well adapted for the bulk facilities of grain custody warehouses.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2013.05a
• /
• pp.18-18
• /
• 2013

A FeRh alloy is a well-known efficient magnetocaloric material and some experimental and theoretical studies of bulk FeRh have been reported already by several groups. In this study we report first-principles calculations on magnetic properties of different thickness FeRh thin films in order to investigate the possibility to enhance further the magnetocaloric efficiency. We used Vienna Ab-initio Simulation Package (VASP) code. We found that the FeRh thin films have quite different magnetic properties from the bulk when the thickness is thinner than 6-atomic-layers. While bulk FeRh has a G-type antiferromagnetic (AFM) state, thin films which are thinner than 6-atomic-layers have an A-type AFM state or a ferromagnetic(FM) state. We will discuss possibility of magnetic phase transitions of the FeRh thin films in the view point of a magnetocaloric effect. And we found 4-, 5-, 6-layers films with Fe surface and 7-layers film with Rh surface are FM and they have dozens eV magnetocrystalline anisotropy (MCA) energy. MCA energy leads to determine energy barrier when magnetic states are changed by external magnetic field.