• Journal of Korean Society of Water and Wastewater
• /
• v.25 no.4
• /
• pp.479-488
• /
• 2011

Nanofiltration was performed with polyaluminium chloride solutions at different pH conditions to understand effects of inorganic compounds on aluminum hydrolysis products, i.e., three distinctive groups of aluminum species: polymeric Al at low pH; $Al(OH)_3$ at neutral pH; and ${Al(OH)_4}^-$ at high pH. The PACl solution was prepared to be approximately 4.0mM and adjusted to the designated pH. The influence of inorganic compounds on Al species fouling was investigated with 4.9mM $CaCl_2$ and 3.5mM $MgSO_4$ because $Ca^{2+}$, $Mg^{2+}$, $Cl^-$, ${SO_4}^{2-}$ are the most common inorganics in the drinking water. NF membrane fouling was measured by flux decline rate. The impact of $CaCl_2$ was not significant on the individual Al hydrolysis products fouling. However, the flux decline rate was drastically changed in the presence of $MgSO_4$. The concentration of particulate matters was considerably increased possibly due to interaction between Al species and ${SO_4}^{2-}$ where $MgSO_4$ was introduced. The particulates were accumulated on the membrane and enhanced the hydraulic resistance of the cake layer. In addition, conductivity removal of the membrane was decreased when Al-hydroxide was dominant due to reduction of membrane surface charge. The rejection of $Ca^{2+}$and $Mg^{2+}$ were considerably different, which implys that composition of inorganics paly a role on conductivity removal.

• Transactions of the Korean hydrogen and new energy society
• /
• v.6 no.2
• /
• pp.91-100
• /
• 1995

To investigate the surface state of $Mg_2Ni$ which was exposed to the air, a chemical treatment was undertaken with $H_2SO_4$ solution. During chemical treatment, the change of pH was measured continuously and the chemically treated specimen was hydrided to study the effect of chemical treatment on the hydrogenation. The pH changing behavior with the various $H_2SO_4$ concentration appeared very diffemrently. Especially in the solution including 3CC $H_2SO_4$, the behavior of pH change can be divided 3 steps. It is also shown that the $Mg_2Ni$ chemically treated with $H_2SO_4$ can be hydrided even under room temperature. By the SEM observation the was reasion that after chemical treatment the surface of a particle was covered with Ni layer.

• Journal of the Korean institute of surface engineering
• /
• v.21 no.1
• /
• pp.3-9
• /
• 1988

An electroless plating both for normal orientation of HCP-structure of Co-P to the film plane was developed. An ammonical succinate-citrate bath containg MnSo4, NiSO4 was studied Ni was codeposited into the films in order to decrease the saturation magentization (MS) since low Ms is necessary to decrease the magentizing fild. Mn was also codeposited to increase perpendicular orentaon of Co-P film. Effects on film composition and magnetic properties were studid in connection with follwing four factors such as concentration of NiSo4 and MnSo4, bath temp and pH.

• Asian-Australasian Journal of Animal Sciences
• /
• v.11 no.1
• /
• pp.8-12
• /
• 1998

Two experiments were conducted to determine the effects of $MnSO_4$ on controlling harmful microorganisms in vitro and in vivo. The in vitro experiment was conducted to examine the effects of manganese sulfate $(MnSO_4)$ on the reduction of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by growth stimulation of Pediococcus acidilactici (P. acidilactici; lactic acid bacteria). Manganese ion (0.003 %) was found to stimulate the growth of P. acidilactici in the In Vitro system. When E. coli and S. aureus were grown in a mixture with P. acidilactici, their numbers were reduced. This may be the result of a reduction of pH in the medium as a result of better growth of P. acidilactici due to stimulation by the Mn ion. The in vivo experiment was conducted to determine the effects of $MnSO_4$ in diets on controlling harmful microorganisms in fecal samples of pigs. There were no significant differences for the microbial numbers (i.e., total microorganisms, E. coli, lactic acid bacteria and S. aureus) in feces of pigs fed $MnSO_4$ compared to feces of pigs fed the control diet through 7 days. However, on day 7 of experiment, the pH of feces in pigs fed $MnSO_4$ (0.1%) decreased faster than pigs fed the control diet.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.40 no.1
• /
• pp.61-71
• /
• 2003

Interconnect test for highly integrated environments like SoC, becomes more important as the complexity of a circuit increases. This importance is from two facts, test time and complete diagnosis. Since the interconnect test between IPs is based on the scan technology such as IEEE1149.1 and IEEE P1500, it takes long test time to apply test vectors serially through a long scan chain. Complete diagnosis is another important issue because a defect on interconnects are shown as a defect on a chip. But generally, interconnect test algorithms that need the short test time can not do complete diagnosis and algorithms that perform complete diagnosis need long test time. A new interconnect test algorithm is developed. The new algorithm can provide a complete diagnosis for all faults with shorter test length compared to the previous algorithms.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.31 no.1
• /
• pp.15-24
• /
• 2011

The glutathione (GSH) concentration in leaves of different maturities and roots of forage rape (Brassica napus L.) supplied with four levels of external $SO_4^{2-}$ (0, 0.1, 1.0 and 2.0 mM) supply were measured. The relationships of GSH concentration with $SO_4^{2-}$ uptake, ATP sulfurylase (ATPS) and O-acteylserine (thiol) lyase (OASTL) activity were also assessed. The $SO_4^{2-}$ uptake increased in parallel with the external $SO_4^{2-}$ supply, while protein concentration was not significantly changed. The ATPS activity increased continuously with decreasing $SO_4^{2-}$ supply from 2.0 to 0 mM, while the OASTL activity decreased significantly only at S-deficient conditions (0 and 0.1 mM). The GSH concentration in the young leaves, middle leaves and roots continuously increased (except for between 1.0 and 2.0 mM in the middle leaves and roots) as the external S supply was increased, but no significant changes occurred in the old leaves. The increased endogenous GSH concentration, affected by the $SO_4^{2-}$ supply level, was significantly related with the decrease in ATPS activity in both leaves and roots, and the decrease in OASTL activity only in leaves..

• Journal of environmental and Sanitary engineering
• /
• v.9 no.2
• /
• pp.1-7
• /
• 1994

Rainwater was collected in Seoul area from January 1991 to December 1993 (over 3years) and by the analysis of the chemical components contained in rainwater, investigated the components that effect on rainwater pH Through the above studies the following conclusions were obtained. 1) Method for Averaging pH Volume weighted method is considered to be acceptable providing that precipitation is measured at the same time when the samples are taken, without precipitation data a simple averaging method should be the next choice. 2) Annual average rainwater pH was 4.98 in 1991, 4.80 in 1992, 4.67 in 1993, measurement range was 3.6-8.1. 3) In the relationship between rainwater pH and rainfall amounts rainwater pH for light rain(<15mm rainfall) was existent in the wide range(pH 4-7), but for heavy rain was corresponded to the annual average values. 4) Annual frequency of pH was Birrndat the frequency($\gamma $) between the density of the [$H^{+}$] and pH in the rainwater(over 3years ), $NO_{3}^{-}$ was excellent and the obtained results was 0.62 in 1992. Also In the correlation coefficient($\gamma $) according to the pH range $SO_{4}^{2-}, NO_{3}^{-}$, were 0.85 ,0.68 at 3.6 $Cl^-$ was 0.99(1993). At 4.1$NO_{3}^{-}(\gamma=0.48)$ in 1992, SO_4^{2-}($\gamma$=0.54), $NO_{3}^{-}(\gamma$=0.72), $Cl^- (\gamma$=0.49) in 1993. 6) pH values gradually increased with increase in $Ca^{2+}/SO_{4}^{2-}$.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.3
• /
• pp.575-580
• /
• 2017

In these days, the big-size and high resolution multimedia file is widely used through networks. To transfer and service effectively, the internet network technology is necessary to substitute broadcasting. Normally Content Delivery Network(CDN) is widely used in conventional internet for multimedia services. But it has a small bandwidth to service. So to solve this problems, many researchers have suggest the protocol for download, content distribution/saving, server synchronization, caching, pushing rate, and streaming etc. But all of these has some defects like low resolution, packets loss and delay, real application implementations etc. So, this paper suggests a new method of network protocol based on P2P collaboration and user's content using information. And it evaluated the performance of suggested method. As the results, it showed the effectiveness of 4 performances indices : download speed, decreasing rate of connected user in same time, adaptive hit ratio, traffic decreasing rate.

• Journal of the Korean Chemical Society
• /
• v.45 no.1
• /
• pp.7-13
• /
• 2001

The interaction of benzenesulfonate anion and its derivatives ($C_6H_5SO_3^-, p-$CH_3C_6H_4SO_3^-, and $p-C_2H_5C_6H_4SO_3^-$) with the micellar system of cationic surfactant TTAB(tetradecyltrimethylammonium bromide) was studied by UV/Vis spectrophotometric method. The solubilization constants($K_s$) of benzenesulfonate anions into the micellar phase of this surfactant have been measured with the change of temperature. The effects of additives(n-pentanol and NaBr) on the solubilization of benzenesulfonate anions by this surfactant system have been also measured. There was a great decrease on the values of $K_s$ and CMC simultaneously with these additives so that the measured values of ln$K_s$ were linear relationships with the values of lnCMC. For the thermodynamic study, various thermodynamic parameters(${\Delta}G^0_s$, ${\Delta}H^0_s$ and ${\Delta}S^0_s$) have been calculated and analyzed from the dependence of Ks values on temperature.

• Journal of the Korean Ceramic Society
• /
• v.44 no.6 s.301
• /
• pp.325-330
• /
• 2007

High porous AlO(OH) gel is used in precursor of ceramic material, coating material and porous catalyst. For use of these, not only physiochemical control for particle morphology, pore characteristic and peptization but also studies of synthetic method for preparation of high porous AlO(OH) gel were required. In this study, high porous AlO(OH) gel was prepared through the aging and filtration process of aluminum hydroxides gel precipitated by the hydrolysis reaction of $Na_2CO_3$ solution and $Al_2(SO_4)_3$ and $Na_2SO_4$ mixed solution. In this process, optimum synthetic condition of AlO(OH) gel having excellent pore volume as studying the effect of hydrolysis pH on gel precipitates has been studied. Hydrolysis pH brought about numerous changes on crystal morphology, surface area, pore volume and pore size. Physiochemical properties of gel were investigated as using XRD, TEM, TG/DTA, FT-IR and $N_2$ BET method.