• Transactions of Materials Processing
• /
• v.6 no.3
• /
• pp.213-220
• /
• 1997

The microstructure of the inconel 690 alloy was varied by the solution treatment and the thermal treatment. The specimens having different microstructures were examined in order to understand the strengthening mechanism of the inconel 690. The level of supersaturation of carbon in the solid solution was increased by applying a longer solution treatment at 115$0^{\circ}C$. As increased carbon content in the solid solution, more carbides precipitated during the thermal treatment at $700^{\circ}C$. Since the carbides played a role of obstacle on the movement of dislocations, a higher tensile strength was obtained in the sample having a large number of carbider. The accumulation of dislocations at the grain boundary carbides caused the development of intergranular fracture which led to a lower elongation.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.18 no.2
• /
• pp.105-118
• /
• 2015

This study was conducted to obtain proper amount of solid swine manure and poultry manure in the beginning phase of Cornus kousa growth by investigating the initial germination, seedling growth increment, dry weight, chlorophyll content change, body nutrient uptake and chemical changes of soil according to the concentration of solid swine manure and poultry manure fertilization. When treated with solid swine manure and poultry manure, seed germination rate was the highest in the control. However germination rate showed a tendency to decrease when treated with high concentration of swine manure and poultry manure. The survey results of the growth increment were all higher than that of the control. At the 1.0% treatment of both swine and poultry manure, the seedling height growth was highest. Poultry manure treatment made higher result than swine manure treatment at each treatment. Dry weight was the highest at the 1.0% treatment by both swine and poultry manure. Dry amount declined sharply at the 2.0% treatment. Poultry manure was higher in weight than swine manure at every treatment. Chlorophyll content was the highest at the 1.0% treatment by both swine and poultry manure, but declined sharply at the 2.0% treatment. The survey content was higer than that of the control. The amount of nutrients absorbed in the seedling body was generally high at the 1.0% treatment of swine manure and poultry manure. For the planting soil of Cornus kousa the higher concentration of swine manure and poultry manure was, the lower pH became. However, nitrogen, got higher. available phosphoric acid, exchangeable K, Na, and Mg got higher.

• Applied Biological Chemistry
• /
• v.50 no.4
• /
• pp.304-307
• /
• 2007

An efficient production method of spirulina extract was developed by enzymatic treatment using cell lytic and proteolytic enzymes. The suitable dosage of Tunicase, a cell lytic enzyme, was found to be 2.0% (w/w). Proteolytic enzymes were screened to obtain high solid recovery and spirulina extraction (SE) index, which indicates nucleic acid-related substances content. Among the seven tested proteases, Esperase was selected and optimal dosage of this enzyme was 2.0% (w/w). The solid recovery and SE index of simultaneous treatment and co-treatment using optimal dosages of Tunicase and Esperase were greatly similar, respectively. However, co-treatment had the effect of shortening total hydrolysis time. The SE index and solid recovery of co-treatment were significantly enhanced by 75% $(11.4{\rightarrow}20.0)$ and 45% $(45.2%{\rightarrow}65.3%)$, respectively, than those of the non-treated extracts.

• Journal of Korea Foundry Society
• /
• v.40 no.3
• /
• pp.66-75
• /
• 2020

The aim of this study was to optimize a solid solution treatment for a high pressure die casting Al-10Si-0.3Mg-0.6Mn alloy to avoid blistering and to improve the strength of the alloy. To achieve this goal, the number density of the blisters and the strength of the alloy under various solid solution treatment (SST) conditions were evaluated. The SST was performed at 470, 490, 510 and 530℃ for 20, 60, 120, 240 and 480 min on the alloy. The number density of the blisters increased with the increasing temperature and time of the SST and the defect area fraction. The yield strength of the alloy after the T6 heat treatment increased with the increasing SST temperature and time. Based on the results, it is suggested that SST should be performed at 510℃ within 60 min. or at 470 and 490℃ within 240 min. to avoid blistering and to improve the strength.

• Textile Coloration and Finishing
• /
• v.29 no.3
• /
• pp.122-130
• /
• 2017

In the direct digital textile printing process, the pre-treatment process is an essential condition for products by forming a clear pattern by sticking and penetration of DTP dye without spreading on the fabric. Recently, pre-treatment agent is changing from high viscosity to low viscosity in order to reduce defects of fabric during pre-treatment process. In this study, pre-treatment agent of acrylic polymer with low viscosity(less than 50cps) was prepared according to the solid content of the polymer, pre-treated on the cotton fabric, and direct DTP printing was performed to compare the color and sharpness. As a result, it showed high color at a viscosity of 50cps or less. When the solid content of the polyacrylic acid having a high molecular weight(A1) was 2.5wt%, when the solid content of the polyacrylic acid having a low molecular weight(A2) was 1 - 1.5wt%, the color was the best. And when the solid content of A1 and A2 was 1.5wt%, the degree of spreading was small and A1 was superior to A2 at the sharpness.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.8
• /
• pp.3989-3995
• /
• 2012

The aim of the present investigation was to evaluate the effect of A.nilotica extract against Dalton's ascitic lymphoma (DAL) induced solid and ascitic tumors in BALB/c mice. Experimental animals received A.nilotica extract (10 mg/kg.bw) intraperitoneally for 10 and 14 consecutive days before induction of solid and ascitic tumors, respectively. Treatment with A.nilotica extract significantly decreased the development of tumor and percentage increase in body weight when compared to DAL induced solid tumor control group, also increasing the life span, restoring the total white blood cell count and hemoglobin content and significantly decreasing the levels of serum aspartate transaminase (SGPT), alanine transaminase (SGOT), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT) and nitric oxide (NO) when compared to DAL induced ascitic tumor controls. The treatment also reduced significantly the cellular glutathione (GSH) and nitric oxide levels in treated animals. Histopathological studies also confirmed protective influence. The outcome of the present work indicates that A.nilotica extract could be used as natural anticancer agent for human health.

• Journal of Korean Society of Water and Wastewater
• /
• v.22 no.3
• /
• pp.359-366
• /
• 2008

The series of experiments under the various conditions were carried out to evaluate the feasibility of dissolved air flotation (DAF) as an alternative of conventional gravity sedimentation (CGS) and to investigate the decrease of the loadings following to biological wastewater treatment processes in livestock wastewater system. On the basis of the experiment result between CGS and DAF processes, for the other water quality criteria as well as suspended solid the removal efficiency of DAF process was about 20~25 % better than CGS process on average. In addition, the particle removal efficiency of DAF process became higher in proportion as the increase of air to solid (A/S) ratio and the general wastewater treatment efficiency of DAF process was enough to meet the requirement of loading decrease to following biological process even at low A/S ratio range. Though DAF process is widely known as an solid separation unit, there was not the notable relationship between particle separation efficiency and several pollutant removal efficiencies like $COD_{Cr}$ and nutrients (T-N, T-P). Assume that the $COD_{Cr}$ was removed as the fraction of particle separation in this experiment, the removal efficiency of T-N and T-P were sensitive to removal efficiency of $COD_{Cr}$, especially.

• Journal of Korean Society of Water and Wastewater
• /
• v.29 no.1
• /
• pp.57-63
• /
• 2015

Recently, Korea's municipal wastewater treatment plants generated amount of wastewater sludge per day. However, ocean dumping of sewage sludge has been prohibited since 2012 by the London dumping convention and protocol and thus removal or treatment of wastewater sludge from field sites is an important issue on the ground site. The hydrothermal carbonization is one of attractive thermo-chemical method to upgrade sewage sludge to produce solid fuel with benefit method from the use of no chemical catalytic. Hydrothermal carbonization improved that the upgrading fuel properties and increased materials and energy recovery, which is conducted at temperatures ranging from 200 to $350^{\circ}C$ with a reaction time of 30 min. Hydrothermal carbonization increased the heating value though the increase of the carbon and fixed carbon content of solid fuel due to dehydration and decarboxylation reaction. Therefore, after the hydrothermal carbonization, the H/C and O/C ratios decreased because of the chemical conversion. Energy retention efficiency suggest that the optimum temperature of hydrothermal carbonization to produce more energy-rich solid fuel is approximately $200^{\circ}C$.

• Journal of the Korean Ceramic Society
• /
• v.42 no.12 s.283
• /
• pp.846-853
• /
• 2005

For the performance prediction of a planar-type solid oxide fuel cell, the computational analysis of transport phenomena with a simplified treatment of heat generation by the electrochemical reaction is conducted. From the result of the computational analysis, it is shown that the electrochemical reaction is closely related to the transport phenomena inside a solid oxide fuel cell. Transport phenomena including heat and mass transfer influences on the distribution of local current density and, as a result, on the performance characteristics of the fuel cell. Computational analysis is also extended to the parametric study to investigate the performance behavior of the fuel cell with different amount of supplied fuel flow rates. It is also demonstrated that the mathematical formulation and computational procedures proposed in this study can be applied to prove the importance of the specific TPB area in the manufacturing process of electrodes in solid oxide fuel cells.

• Transactions of Materials Processing
• /
• v.10 no.3
• /
• pp.214-222
• /
• 2001

The homogeneous distribution of solid region without liquid segregation is important in terms of high quality component during thixoforming process. In closed die semi-solid forging process, liquid segregation is strongly affected by injection velocity than solid fraction because the material has to travel relatively long distance to fill the cavity through a narrow gate. The designed die by computer simulation data was used to thixoforging process. The thixoforming velocity to prediction the liquid segregation had been determined with strain rate associated with multistage velocity control during compression test of semi-solid material. The optimal forging velocity and die temperature were investigated to produce the near-net-shape compressor component. The mechanical properties of thixoformed component were tested with various die and material temperatures before and after heat treatment.