• Journal of Soil and Groundwater Environment
• /
• v.26 no.6
• /
• pp.65-73
• /
• 2021

Since the amount of red mud, generated from aluminum smelting process as a by-product, has increased worldwide, the recycle and metal resource recovery from the red mud is becoming more important. In this study, in order to recycle the red mud as a soil stabilizer to remediate arsenic contaminated soils, neutralization of red mud was investigated. Red mud was neutralized by washing with distilled water and NaCl, CaCl₂, FeCl₃, and HCl solutions and heating at 200-800℃, and arsenic stabilization characteristics in soils were evaluated with the neutralized red mud. Although washing with distilled water was not effective in neutralizing red mud, the application of the washed red mud to soils lowered the soil pH compared to the application of untreated red mud. Among NaCl, CaCl₂, FeCl₃, and HCl solutions, washing with FeCl₃ showed the most effective in lowering pH of the red mud from pH 10.73 to pH 4.26. Application of the neutralized red mud in soils resulted in quite different arsenic stabilization efficiency depending on soil samples. In M1 soil, which showed relatively high arsenic stabilization efficiency by untreated red mud, the neutralization of red mud resulted in little effect on arsenic stabilization in soil. On the other hand, in M2 soil, which showed low arsenic stabilization efficiency by untreated red mud, the neutralization of red mud increased arsenic stabilization significantly. Soil characteristics such as clay minerals and pH buffering capacity seemed to affect reactions between red mud and soils, which resulted in different effects of the red mud application on soil pH and arsenic stabilization efficiencies.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.8 no.2
• /
• pp.343-349
• /
• 1998

The effect of pH on the dehydration reaction of $TiCL_4$ solution. KOH and HC1 were used as a accelerater and retarder in dehydration. Results are follow. Neutralization point is pH 7.4 in the system of $TiCL_4$- KOH and the production which is produced at acidic side is Ti -gel of poly metatitanic acid. The production which is produced at alkalic side is aligomer and crystalline potasium titanate is not detected.

• Korean journal of food and cookery science
• /
• v.8 no.1
• /
• pp.57-63
• /
• 1992

The purpose of this study was to investigate the rheological and thermal properties of yam starch. Yam starch had a hydrodynamic volume with the intrinsic viscosity,［$\eta$］, of 0.29dl/g deionized water. The values of the intrinsic viscosity of yam starch, determined to pH 2-11, varied between 0.07 to 0.18 dl/g. The highest intrinsic viscosity was obtained at pH 7. At salt concentrations 0-0.2 M NaCl, the intrinsic viscosity of yam starch was decreased up to 0.05 M NaCl concentration then increased to 0.07 M NaCl concentration and remained constant to reach 0.2 M NaCl concentration. The overlap parameter, calculated with the intrinsic vicosity data, was 3.45 g/dl in deionized water. The thermal properties of yam starch were investigated by Differential Scanning Calorimetry. Three endotherms were observed both pH solution and salt concentation. In the presence of pH 9, the onset temperature of gelatinization peak was the lowest temperature of 50.$32^{\circ}C$ and the enthalpy ($\Delta$H) was increased in this solution. The effect of salt on the thermal properties of yam starch was determined at salt concetration of 0-0.2 M NaCl. The enthalpy significantly decreased to salt concentration 0.07 M NaCl and the lowest onset temperature of this concentration was 52.$90^{\circ}C$.

• Journal of Microbiology and Biotechnology
• /
• v.13 no.2
• /
• pp.182-190
• /
• 2003

A new phaC gene cluster encoding polyhydroxyalkanoate (PHA) synthase I PHA depolymerase, and PHA synthase II was cloned using the touchdown PCR method, from medium-chain length (mcl-) PHA-producing strain Pseudomonas putida KT2440. The molecular structure of the cloned phaCl gene was analyzed, and the phylogenic relationship was compared with other phaCl genes cloned from Pseudomonas species. The cloned phaCl gene was expressed in a recombinant E. coli to the similar level of PHA synthase in the parent strain P. putida KT2440, but no significant amount of mcl-PHA was accumulated. The isolated phaCl gene was re-introduced into the parent strain P. putida KT2440 to amplify the PHA synthase I activity, and the recombinant P. purida accumulated mcl-PHA more effectively, increasing from 26.6 to $43.5\%$. The monomer compositions of 3-hydroxylalkanoates in mcl-PHA were also modified significantly in the recombinant P. putida enforcing the cloned phaCl gene.

• Archives of Pharmacal Research
• /
• v.13 no.3
• /
• pp.233-239
• /
• 1990

The efect of acute renal failure (ARF) on the pharmacokinetics o sulfobromophthalein (BSP) was investigated in order to elucidate if renal failure modifies the hepatic metabolism of drugs. ARF was induced by intravenous (iv) injection of uranyl nitrate (UN) to rats (5 mg/kg) five days before the experiment. Area under the plasma concentration-time curve (AUC)of BSP after portal vein (pv) injection increased by 2-fold and total body clearance ($CL_1$) decreased one half (p <0.01) in UN-induced ARF (UN-ARF) rate compared to the control rats. But the plasma disappearance of BSP after iv injection did not differ significantly between control and UN-ARF rats. Since BSP is excreted via the liver, $CL_1$ represented the approximate hepatic clearance of BSP. Therefore, the decrease in $CL_1$ represented the approximate hepatic clearance of BSP. Therefore, the decrease in $CL_1$ represents a decrease in hepatic intrinsic clearance ($CL_{int}$) for BSP since plasma free fraction ($f_p$) of BSP was not affected by UN-ARF. The content of hepatic cytoplasmic Y-protein, which catalyzes BSP-glutathione conjugation and limits the trasfer of BSP from blood to bile, increased significantly (p < 0.01), however its binding activity (BA) for BSP was decreased significantly (p <0.01) by UN-ARF. The decrease in $CL_{int}$might have some correlation with the changed characteristics of hepatic Y-protein, specifically its decreased BA for BSP.

• Journal of Korean Society of Environmental Engineers
• /
• v.37 no.6
• /
• pp.325-331
• /
• 2015

The experimental results of the characteristics of aluminum based and ferric based coagulants for the Nakdong River water showed that the main hydrolysis species contained in alum and $FeCl_3$ are monomeric species of 98% and 93.3%, respectively. The PACl of r=1.2 produced by the addition of base contained 31.2% of polymeric Al species and the PACl of r=2.2 contained 85.0% of polymeric Al species, as showing more polymeric Al species with increasing r value. Coagulation tests using Al(III) and Fe(III) salts coagulants for the Nakdong River water showed that the coagulation effectiveness of turbidity and organic matter was high in the order of $FeCl_3$ > PACl (r=2.2) > PACl (r=1.2) > alum. $FeCl_3$ has showed better flocculation efficiency than Al(III) salts coagulants. In addition, in case of Al(III) coagulants, the Al(III) coagulants of higher basicity, which contained more polymeric Al species, resulted in better coagulation efficiency for both turbidity and organic matter removed. The optimum pH range for all of the coagulants investigated was around pH 7.0 under the experimental pH range of 4.0~9.5. Especially, the highest basicity PACl (r=2.2) and $FeCl_3$ were considered as more appropriate coagulants for the removal of turbidity in the case of raw water exhibiting higher pH.

• International Journal of Human Ecology
• /
• v.14 no.2
• /
• pp.93-103
• /
• 2013

This study investigated the relationship of clothing microclimate and physiological responses in order to examine the layering effects on the clothing microclimate as an index to predict clothing thermal insulation ($I_{cl}$). Experiments were conducted in a $15^{\circ}C$ environment on six physically active males. Increased clothing layers resulted in higher mean temperature inside the clothing ($\bar{T}_{cl}$) and $I_{cl}$. The $I_{cl}$ had a high correlation with: $\bar{T}_{cl}$ (r = 0.556), the difference between the innermost surface temperature and the outermost surface temperature at the chest (DST) (r = 0.549) and the temperature inside clothing at the abdomen (r = 0.478). $\bar{T}_{cl}$ had the highest correlation with the temperature inside clothing at the abdomen (r = 0.889). $\bar{T}_{cl}$ also had the highest correlation with $\bar{T}_{sk}$ (r = 0.860). The results showed that the relationship between $I_{cl}$ and $\bar{T}_{cl}$ was linear (p < .01). Thermal comfort had a negative correlation with $\bar{T}_{cl-thigh}$ (r=-0.411) and $\bar{T}_{cl}$ (r = -0.323) (p < .01.)

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.1
• /
• pp.75-84
• /
• 2005

The aim of this study is to evaluate the leaching characteristics of lead, copper, cadmium, and mercury from steel making slag by seawater. To demonstrate the leaching characteristics of heavy metals from steel making slag by seawater, it was carried to various leaching tests such as regular leaching tests, liquid/sold(LS) leaching test and pH static test. From the leachability of $Pb^{+2},\;Cu^{+2},\;and\;Cd^{+2}$ from steel making slag in pH static test, it is distinguished between distilled water and seawater. With distilled water, it is very low between pH 7-8 and pH 11-12. On the other hands, with the seawater, its leaching is higher than that of distilled water. In particular, concentration of $Hg^{+2}$ leached from slag by seawater is lower than that of distilled water. Meanwhile, we found that the heavy metals from steel making slag would be dissolved and precipitated using geochemcial equilibrium program such as visual minteq. Lead and copper leached from steel making slag with seawater were dissolved nearly in the range of pH 11-12, but in the range of pH 7-10 those were precipitated about 90%. And cadmium leached from steel making slag with seawater were dissolved completely. On pH static test with distilled water, lead leached from steel making slag seemed to be similar to pH static test with seawater. However, copper and cadmium leached from steel making slag were dissolved. In general, the species of lead leached from steel making slag were formed mainly of $PbCl^+,\;PbSO_4$, the species of copper were formed mainly of $CuSO_4,\;CuCO_3$, the species of cadmium were formed mainly of $CdCl^+,\;CdSO_4$ due to being sorbed with the anions($Cl^-,\;CO_3^{-2},\;SO_4^{-2}$) of the seawater. Both pH static test with seawater and distilled water, it is not in the case of the mercury. Most of mercury leached from steel making slag was precipitated(SI=0). Because the decreasing of $Hg^{+2}$ concentrations depends ferociously on the variation of chloride($Cl^-$) existed in the seawater. $Hg^{+2}$ leached from steel making slag could be sorbed strongly with chloride($Cl^-$) compared of carbonate($CO_3^{-2}$) and sulfate($SO_4^{-2}$) in the seawater. On the basis of that result, we found that the species of mercury was formed of calomel($Hg_2Cl_2$) as one of finite solid. Due to forming a calomel($Hg_2Cl_2$) in the seawater, the stability of mercury species by steel making slag should be higher than those of lead, copper, and cadmium species. Regarding the results stated above, we postulated that the steel making slag could be recycled to sea aggregates due to being distinguishing leachability of heavy metals($Pb^{+2},\;Cu^{+2},\;Cd^{+2},\;and\;Hg^{+2}$) between leaching tests by distilled water and seawater.

• Korean Journal of Poultry Science
• /
• v.47 no.2
• /
• pp.75-82
• /
• 2020

This study intended to investigate the growth performance and meat quality traits in broilers fed different regimens of NaCl over a period of 35 days. Seven hundred and fifty 1-day-old chicks (Cobb 500) were randomly assigned to five NaCl feeding regimens to obtain three replicates for each regimen. Broilers in CON group were provided with concentrations of 0.35% NaCl for the duration of the experimental period. The other groups were provided with two concentrations of NaCl (0.45% and 0.55%) under two durations, namely: 1) 1~28 d: 0.45% or 0.55% NaCl for 28 days then CON; and 2) 1~35 d: 0.45% or 0.55% NaCl for 35 days. Broilers fed 0.55% NaCl for 1~35 d showed improved (P<0.05) growth performance compared with broilers fed the CON regimen. Moreover, higher water holding capacity of breast meat was shown by the broilers fed 0.55% NaCl for 1~28 d when compared with that in broilers fed the CON diet (P<0.05). Broilers fed 0.45% NaCl showed an increase (P<0.05) in the lightness of the meat over CON diet and the 0.55% NaCl diet. In addition, broilers offered CON had the highest redness value and highest crude ash content in the breast meat (P<0.05). Feeding 0.45% NaCl for 1~35 d and 0.55% NaCl for 1~28 d resulted in a higher (P<0.05) protein content in breast meat. In conclusion, broilers fed diets with 0.55% NaCl for 1~35 d showed improved growth performance as well as water holding capacity and protein content of the breast meat.

• Journal of Life Science
• /
• v.22 no.4
• /
• pp.552-558
• /
• 2012

Severe acute respiratory syndrome (SARS) is a severe respiratory infectious disease caused by a novel human coronavirus, SARS-CoV. The 3CL protease is a key enzyme in the proteolytic processing of replicase polyprotein precursors, pp1a and pp1ab, which mediate all the functions required for viral genomic replication and transcription. Therefore, this enzyme is a target for the development of chemotherapeutic agents against SARS. A large quantity of active SARS-3CL protease is required for development of anti-SARS agents. Here we have constructed overexpression vector for the production of the SARS-3CL protease. The gene encoding SARS-3CL protease was amplified using polymerase chain reaction and cloned into the pET29a expression vector, resulting in pET29a/SARS-3CLP. Recombinant SARS-3CL protease was successfully synthesized by the dialysis mode of the cell-free protein expression system, and purified by three-step fast protein liquid chromatography using HighQ and MonoP column chromatographies and Sephacryl S-300 gel filtration. In addition, the produced SARS-3CL protease was found to be an active mature form. This study provides efficient methods not only for the development of anti-SARS materials from natural sources, but also for the study of basic properties of the SARS-3CL protease.