• Korean Journal of Food Science and Technology
• /
• v.27 no.6
• /
• pp.915-920
• /
• 1995

This study was performed to investigate the effect of aluminum compound on the aluminum contents and histological change in brain tissue of rats. Seventy five male Sprague-Dawley strains were divided into five groups consisting of the control, 250 ppm $AlCl_3$ group, 500 ppm $AlCl_3$ group, 250 ppm $Al_2(SO_4)_3$ group, 500 ppm $Al_2(SO_4)_3$ group and kept on the diet for 2 weeks. The weight gain was increased by administration of $AlCl_3$ but decreased by administration of $Al_2(SO_4)_3$ as compared to control group. The aluminum contents in brain tissue of each group; 250 ppm $AlCl_3$ group, 500 ppm $AlCl_3$ group, 250 ppm $Al_2(SO_4)_3$ group and 500 ppm $Al_2(SO_4)_3$ group were 64.63, 102.21, 132.64 and 180.41 ppm, respectively. Aluminum accumulation in brain tissue was higher with administration of $Al_2(SO_4)_3$ than with administration of $AlCl_3$. In $AlCl_3$ administration group, multiple small intracytoplasmic granules and microvacuole were seen in large pyramidal cells of cortex and granulovacuolar degeneration. In $Al_2(SO_4)_3$ administration group revealed pollagis pallor, cellular pyknosis, microcavitation resulted from edema in deeper cortical layers were observed. Blue-pigmentation which represents the accumulation of aluminum was noted In granulovacuolar degeneration site in $Al_2(SO_4)_3$ administration group.

• Journal of Conservation Science
• /
• v.29 no.1
• /
• pp.47-54
• /
• 2013

The following study tests for the effects of mordants on the production of restoration papers during the conservation process of damaged paper artifacts. For this, four different types of synthetic mordants that are being marketed currently ($K_2CO_3$, $AlK(SO_4)_2{\cdot}12H_2O$, $Cu_2SO_4{\cdot}5H_2O$, $FeSO_4$) were selected to produce samples for measuring variable properties through artificial degradation. The research conducts tests for changes in color, tensile index, and pH level (degree of acidity). The results for changes in color have shown that the value of ${\Delta}E^*ab$ of $K_2CO_3$ mordant sample was the highest, and the tests for tensile index have shown that the strength of dyeing sample was decreased in accordance with the aging time, but Changes according to the mordant was not evident. Finally, the findings for pH level have shown that samples with $Cu_2SO_4{\cdot}5H_2O$ and $FeSO_4$ have pH levels drop below 6. As a result, the research have concluded that mordants used for dyeing restoration paper were identified to have an affect in the dyeing and aging characteristics of the paper.

• 한국전기화학회:학술대회논문집
• /
• 2004.04a
• /
• pp.47-47
• /
• 2004

• Journal of Korean Society for Atmospheric Environment
• /
• v.12 no.4
• /
• pp.389-398
• /
• 1996

In order to understand the relative importance of various pathways leading to the production and transformation of aerosols under different atmospheric conditions, the behavior of atmospheric aerosols have been investigated using a high volume tape sample in Seoul for a week period during August 1990. The concentrations of anion $(SO^{2-}_4, NO^-_3, CI^-)$ and cation $(Ca^{2+}, Na^+, NH^+_4)$ species of aerosol samples were analyzed to identify the ionic composition of aerosols and to estimate their relative contributions to aerosol formation. The concentrations of aerosol species were calculated by a multiple regression model. The results of our calculations indicate the existence of various chemical species such as $(NH_4)_2SO_4, Na_2SO_4, CaSO_4, NH_4NO_3, NaNO_3, Ca(NO_3)_2, NH_4Cl$, and NaCl salts. According to our calculations, the most dominant species of aerosol was $(NH_4)_2SO_4$ with the mean concentration of 23.3 $/mu g/m^3$ (66.9%). The proportion of different componts with aerosol (e.g., $NH_4NO_3$ and $NH_4Cl$) was strongly affected by temperature, relative humidity, and partial presure of gases.

• Journal of Korean Society for Atmospheric Environment
• /
• v.10 no.4
• /
• pp.245-251
• /
• 1994

We considered that characteristics of SO$_2$, concentration level and relations of the meteorological parameters and high pollution concentration from the data measured 7 air quality continuous monitoring stations during 4 years, from 1990 to 1993 in Pusan. The SO$_2$ concentration level showed decreasing trend yearly, it was maximum in Winter, minimum in Summer. The time of SO$_2$ peak concentration lagged from seashore to land because of break-down of the nocturnal inversion layer and seabreeze. Ihe correlations of daily SO$_2$, value between various air quality continuous monitoring stations were highest between Beomcheondong and Meongryundong, lowest between Daeyeondong and Sinpyeongdong because of difference of air Pollution emission sources characteristic. The meteorological parameters affecting SO$_2$ concentration level were minimum temperature, relative humidity, wind speed and air pressure. The SO$_2$ high pollution($\geq$95ppb) occurred almost in Winter, particulaly in such day showing lower wind speed and higher air pressure. Elementary SO$_2$ high Pollution Predictor were high pressure system and stability of lower atmosphere.

• Journal of agriculture & life science
• /
• v.45 no.2
• /
• pp.35-41
• /
• 2011

This study was carried out to investigate the relation of acid depositions and chlorophyll concentration in the Pinus thunbergii leaves. pH of throughfall in Pinus thunbergii forest was 4.20 at industrial sites, and 4.87 at urban sites. Total chlorophyll concentration in leaves were 0.5984 at industrial sites, and 0.6784 at urban sites. The average $SO_2$ concentration in air was 0.029ppm at industrial sites, and 0.011ppm at urban sites. Correlation between chlorophyll concentration in the Pinus thunbergii leaves and acid depositions was pH (r=-0.8769), ${NO_3}^-$ (r=0.6983), ${SO_4}^{2-}$ (r=0.8929), $SO_2$ (r=0.8738), and $NO_2$ (r=0.8523) (p<0.001). respectively. The estimation equation of chlorophyll concentration in the Pinus thunbergii leaf (Y) were given by Y=4.8979 + 0.7698pH + $0.8412{SO_4}^2$ + $0.8673SO_2$, + $0.8767NO_2$+ $0.8767{NO_3}^-$ ($r^2$=0.8873), which coefficients of determination was 0.88.

• Magazine of the Korea Concrete Institute
• /
• v.11 no.2
• /
• pp.85-94
• /
• 1999

It was investigated to evaluate the characteristics of cement-flyash paste which was affected the replacement level, curing method and chemical admixtures. The strength of cement-flyash paste was lower than that of cement paste only and the differences increased with increasing the replacement level. However, in steam curing, the strength of cement-flyash pastes was improved and specially, the early strength was effectively increased. The inclusion of $Na_2SO_4$ increased the early strength of cement-flyash paste. In addition, the strength of concrete including 30% of fly ash and $Na_2SO_4$ has improved and obtained the highest strength compared to other concrete mixes.

• Journal of Microbiology and Biotechnology
• /
• v.5 no.2
• /
• pp.96-99
• /
• 1995

Addition of l00mM $MgSO_4$ to a cell culture after 54 hours resulted in a 2.4-fold increase in the sisomicin titre compared to a control to which no $MgSO_4$ was added, and a considerable amount of intracellular sisomicin was liberated outside the cells. The occurrence of product inhibition in fermentation was confirmed by a reduction in net sisomicin production with increasing amounts of added sisomicin without addition of $MgSO_4$. All added sisomicin was bound to sisomicin-free cells in the absence of $MgSO_4$, whereas approximately 40% of added sisomicin was bound with the addition of l00mM $MgSO_4$. Under conditions of no enzmye synthesis, maintained by adding chloramphenicol to exclude product repression, sisomicin was produced in the presence of 100 mM $MgSO_4$ but little sisomicin was produced in the absence of $MgSO_4$.

• Journal of Electrochemical Science and Technology
• /
• v.2 no.2
• /
• pp.76-84
• /
• 2011

Potentiostatic oxidation of Pb-1.7%Sb alloy used in the manufacture of grids of lead-acid batteries over the potential range from -1.0V to 2.3V in 5M $H_2SO_4$ in the absence and the presence of 0.4M $H_3PO_4$ and the self-discharge characteristics of the oxide layer formed is studied by electrochemical impedance spectroscopy (EIS). Depending on the potential value, sharp variations in resistance and capacitance of the alloy are recorded during the oxidation and they can be used for identification of the various substances involved in passive layer. Addition of $H_3PO_4$ is found to deteriorate the insulating properties of the passive layer by the retardation of the formation of $PbSO_4$. $H_3PO_4$ completely inhibits the current and impedance fluctuations recorded in $H_3PO_4$-free solutions in the potential range 0.5 V-1.7 V. These fluctuations are attributed to the occurrence of competitive redox processes that involve the formation of $PbSO_4$, $PbOSO_4$, PbO and $PbO_2$ and the repeated formation and breakdown of the passive layer. Self-discharge experiments indicate that the amount of $PbO_2$ formed in the presence of $H_3PO_4$ is lesser than in the $H_3PO_4$-free solutions. The start of transformation of $PbSO_4$ into $PbO_2$ is greatly shortened. $H_3PO_4$ facilitates the diffusion process of soluble species through the passive layer ($PbSO_4$ and basic $PbSO_4$) but impedes the diffusion process through $PbO_2$.

• Journal of Electrochemical Science and Technology
• /
• v.9 no.2
• /
• pp.85-92
• /
• 2018

Olivine structure of $LiFePO_4$ (LFP) is one of the most commonly used materials in aqueous rechargeable lithium batteries (ARLBs), and can store and release charge through the insertion/de-insertion of $Li^+$ between LFP and FP. We have fabricated LFP and LFP/FP electrodes on titanium paper and studied their electrochemical properties in 2 M $Li_2SO_4$. The LFP/FP electrode was determined to be a suitable electrode for electo-ostmotic pump (EOP) in terms of efficiency in water and 0.5 mM $Li_2SO_4$ solution. Experiments to determine the effect of cations and anions on the performance of EOP using LFP/FP electrode have shown that $Li^+$ is the best cation and that the anion does not significantly affect the performance of the EOP. As the concentration of $Li_2SO_4$ solution was increased, the current increased. The flow rate peaked at $4.8{\mu}L/30s$ in 1.0 mM $Li_2SO_4$ solution and then decreased. When the EOP was tested continuously in 1.0 mM $Li_2SO_4$ solution, the EOP transported approximately 35 mL of fluid while maintaining a stable flow rate and current for 144 h.