• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.454-458
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• 2007

The removal characteristics of ionic species, such as $Ca^{2+}$, $Mg^{2+}$, $Sr^{2+}$, $SO{_4}^{2-}$, $NO{_3}^-$, and $Cl^-$ by adsorption on the alumina were investigated. Alumina precusor powders were prepared from $Al(NO_3)_3{\cdot}9H_2O$ and $NH_4OH$. Alumina materials prepared from the heat treatment in a furnace at $450{\sim}750^{\circ}C$ for 5 h were analysed using FT-IR and the Brunauer-Emmett-Teller (BET) method. The specific surface area of the product particles decreased significantly with treatment temperature. The adsorption capacities of $SO{_4}^{2-}$and $NO{_3}^-$ on alumina were 23 mg/g and 12.4 mg/g, respectively. But, removal efficiencies of $Cl^-$ were less than 4 mg/g. In general, the removal efficiencies of the anion species were decreased with increasing treatment temperature. The best anion removal efficiency was obtained when the alumina was treated under $450^{\circ}C$. Removal efficiencies of $Ca^{2+}$, $Mg^{2+}$, and $Sr^{2+}$ were increased with increasing treatment temperature.

• Bulletin of the Korean Chemical Society
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• v.20 no.5
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• pp.535-538
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• 1999

Five coordinated water-soluble iridium(l) complex, IrH(CO)(TPPTS)3 (1) (TPPTS = P(m-C6H4SO3Na)3-xH2O) has been prepared from the reaction of IrCl3·3H2O with TPPTS and HCHO in H2O/EtOH solution. Complex 1 catalyzes the hydration of nitrites (RC ≡ N, R = CH3, CICH2, CH3(CH2)4, Ph) in aqueous solution to give the corresponding amides (RCONH2) at 100℃. The hydration of unsaturated nitrites (R'C ≡ N, R'=CH3CH=CH, CH3OCH=CH, trans-PhCH=CH, CH2=C(CH3)) takes place regioselectively on-C ≡ N group to give unsaturated amides (R'CONH2) leaving the olefinic group intact. The yields of the amides seem to be depending on the electrophilicity of the carbon of nitrile: The more the electron withdrawing ability of the substituents on nitrites, the more amides are obtained. The hydration of dinitriles (NC-R-CN, R=(CH2)4, (CH2)6) with complex 1 initially gives mono-hydration products (NC-R-CONH2) which are slowly hydrated further to give dihydration products (H2NCO-R-CONH2). The hydration of 1,4-dicyanobutane has been found to be somewhat faster than that of 1,6-dicyanohexane.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.231-232
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• 1998

The purpose of this study was to examine whether the precipitation of calcium phosphate on titanium surface was affected by surface modification. To improve the bone conductivity, of titanium, samples were devided into 4 groups. Group 1 was immersed in 5M-NaOH solution at $60^{\circ}C$ for 24 hours. Group 2 was immersed in 5M-NaOH solution at $60^{\circ}C $ for 24 hours and heat-treated at $600^{\circ}C$ for 1 hour. Group 3 was anodized in Hanks' solution at 1V, $25^{\circ}C$ for 1 hour. Group 4 was anodized in Hanks' solution at 5V, $80^{\circ}C$ for 5 minutes. And then, all specimens were immersed in the MEM Eagle's medium whose composition was similar to that of extracellular fluid for 30 days. The precipitation of the calcium phosphate on implant surface was increased by the immersion in the NaOH solution, and more highly accelerated by heat treatment at $600^{\circ}C$. The precipitation of the calcium phosphate on titanium implant was increased with the treatment of the anodic oxidation in Hanks' solution at 5V, $80^{\circ}C$.

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.507-513
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• 1996

Three sesquiterpene lactone compounds, two novel(1.betha.,3.betha.-dihydroxy-6.betha.,11.betha.,4.alpha.,5.alpha.,7.alpha.H -eudesm-12, 6-olide-1-O-.betha.-D-glucopyranoside, 1.betha.,3.betha.-dihydroxy-6.betha.,11.betha.,4.alpha.,5.alpha.,7.alpha.H-eudes m-12,6-olide-1-O-.betha.-D-glucopyranoside) and 1.betha.,3.betha.-dihydroxy-6.betha.,11.betha.,4.alpha.,5.alpha., 7.alpha.H-eudesm-12,6-olide were isolated from the aqueous fraction of MeOH extract of the roots from Taraxacum hallaisanensis (Compositae) employing Amberlite XAD-2, ODS-gel, silica gel and Sephadex LH-20 column chromatographics. Another known compound, (-)-epicatechin, was isolated from the aqueous fraction of the MeOH extract. The total MeOH extract also contained phytosterol and a mixture of .betha.-amyrin acetate, .alpha.-amyrin acetate and lupeol acetate. Structures of isolated compounds were elucidated by spectroscopic parameters of IR, Mass, /sup 13/C-NMR, /sup 1/H-NMR, /sup 1/H-/sup 1/H COSY, /sup 13/C-/sup 1/H COSY and HMBC.

• Preventive Nutrition and Food Science
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• v.5 no.3
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• pp.131-135
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• 2000

The inhibitory effect of various organic acids on the growth and survival of Escherichia coli O157:H7 in tryptic soy broth with 0.6% yeast extract at 37$^{\circ}C$ or 4$^{\circ}C$ was determined. Minimal inhibitory pHs of acetic acid, citric acid, fumaric acid, hydrochloric acid and lactic acid were 5.0, 4.0, 4.5, 4.0 and 4.5, respectively. Acetic acid (0.012 m) showed the strongest antimicrobial activity, based on the pH values or equivalent molar concentrations, followed by lactic acid (0.0006 M), fumaric acid (0.004M) and citirc acid (0.004 M), respectively, E. coli O157:H7 with an initial inoculum of {TEX}$10^{7}${/TEX} CFU/ml and {TEX}$10^{5}{/TEX} CFU/ml in tryptic soy broth supplemented with 0.6% yeast extract, acidified to target pH with citric, fumaric and lactic acids at 37$^{\circ}C$, was completely inactivated after 7 d and 5 d incubation, respectively, except for the acetic acid (9 d). The bactericidal effect decreased at the same pH when the incubation temperature a was reduced from 37$^{\circ}C$ to 4$^{\circ}C$. The pH values of 0.2% acetic (pH 5.1), 0.6% citric (pH 4.2) and 0.4% lactic acid (pH 4.3) in TSBYE were almost correspondent to the minimal inhibitory pH values on E. coli O157:H7 of acetic (pH 4.0), citric (pH 4.0) and lactic acids (pH 4.5).

• Journal of Sensor Science and Technology
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• v.22 no.4
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• pp.302-307
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• 2013

The Sb-doped $SnO_2$ nanowire network sensors were prepared by thermal evaporation of the mixtures between tin and antimony powders. Pure $SnO_2$ nanowire networks showed high sensor resistance in air ($99M{\Omega}$), similar gas responses to 4 diffferent gases (5 ppm $C_2H_5OH$, CO, $H_2$, and trimethylamine), and very sluggish recovery speed (90% recovery time > 800 s). In contrast, 2 wt% Sb-doped $SnO_2$ showed the selective detection toward $C_2H_5OH$ and trimethylamine, relatively low resistance ($176k{\Omega}$) for facile measurement, and ultrafast recovery speed (90% recovery times: 6 - 18 s). The change of gas sensing charactersitics by Sb doping was discussed in relation to gas sensing mechanism.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.545-548
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• 2008

In this study aluminium sulfate, Ca(OH)$_2$, K-R Slag and $Na_2SO_4$ were used as active admixtures and their concentration 1, 3, 5, 7 weight percent in cement. The physical properties of active admixtures cement mortar were investigated by flow test and compressive strength. It was found that the resulting active admixtures exhibited the higher compressive strength than OPC mortar up. From the test results, cement mortars added active admixture have a good fundamental property.

• Archives of Pharmacal Research
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• v.4 no.2
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• pp.109-115
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• 1981

In the present investigation, an attempt has been made to apply the methods of classical chemical kinetics to the hydrolytic reaction of pipethanate hydrochloride. By successively keeping all but one variable essentially constant, it has been possible to resolve the overall effect of the individual contributing factors. Since nearly all commercial pipethanate preparations are formulated with antacid, studies were made at several constant hydrogen ion concentration ranging pH 0.4 to 7.5. Rate measurement was also carried out in temperature ranging from $25^{\circ}C$ to $60^{\circ}C$. The hydrolysis of pipethanate is found to be of first order with respect to pipeethanate concentration over an experimental range of hydrogen ion concentration (pH 0407.5). The apparent activation energy(Ea) at pH 7.5 is 18.30 Kcal/mole and the frequency factor is $1.1408 {\times}10^{9}sec^{-1}$. The rate of the hydrolysis has a minimum at pH 2.5-3.5. In this region the half-life of pipethanate was about15.3 days at $60^{\circ}C$. The catalytic effect of water was found to be $K_{H_2O}$ = $3.16{\times}10^{-5}min^{-1}$ at $60^{\circ}C$. The catalytic constants of the hydroxyl ions and hydrogen ions at $60^{\circ}C$ were also found to be $K_{OH}$ = $4.5519{\times}10^{-5}min^{-1}$ and $K_{H}+$ = $1.1568{\times}10^{-2}min^{-1}$, respectively. This reaction appears to be primarily base catalyzed hydrolysis and pipethanate is relatively reluctant toward acid catalyzed hydrolysis. A positive primary salt effect was noted in the solution of phpethanate at pH 7.5 and at $60^{\circ}C$.

• Journal of the Korean Wood Science and Technology
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• v.41 no.6
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• pp.566-575
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• 2013

The fruits of Taxus cuspidata were collected, divided into seeds and fruits, and extracted with 95% EtOH. The extracts were evaporated under the reduced vacuum pressure, concentrated, then successively fractionated with a series of n-hexane, dichloromethane, ethyl acetate and water on a separatory funnel to get some freeze dried samples. A portion of the EtOAc (arils:1.65 g, seeds:1.04 g) and $H_2O$ (arils:7 g, seeds:10 g) soluble samples were chromatographed on a Sephadex column using MeOH-$H_2O$ (1:1, 1:3, 1:5, v/v), EtOH-hexane (3:1, v/v) mixture and 100% $H_2O$ as eluting solvents to isolate pure compounds from the fractions. The isolates were developed by cellulose TLC using t-BuOH-HOAc-$H_2O$ (TBA; 3:1:1, v/v/v) and 6% aqueous HOAc. Visualization was done under ultraviolet light and by spraying the vanillin-HCl-EtOH reagent (4.8:12:480, v/v/v). followed by heating. The structures of the isolates were characterized by $^1H$- and $^{13}C$-NMR, DEPT, 2D-NMR, LC/MS and EI-MS spectra. In addition to the NMR and MS spectra, acid hydrolysis and permethylation were used to determine the correct structure of the isolated sugar compound. Their structures were elucidated as (+)-catechin (1), (-)-epicatechin (2), (+)-gallocatechin (3), (-)-epigallocatechin (4) and ${\beta}$-D-fructofuranose-($2{\rightarrow}4$)-O-${\beta}$-D-glucopyranose($1{\rightarrow}4$)-O-${\alpha}$-D-glucopyranose ($1{\rightarrow}2$)-O-${\beta}$-D-fructofuranose (5) on the basis of the above experimental evidences.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.59-67
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• 2018

This study was conducted to isolate the cellulolytic bacteria able to grow on LB- Carboxymethyl cellulose (CMC) agar trypan blue medium from the mixed forest and Larix leptolepis stands. Three bacterial strains with high activity against both CMC and xylan were isolated. Both API kit test and 16S rRNA gene sequence analysis revealed that the three different isolates belong to the gene Bacillus. Therefore, the isolates named as Bacillus sp. EFL1, Bacillus sp. EFL2, and Bacillus sp. EFP3. The optimum growth temperature of Bacillus sp. EFL1, EFL2, and EFP3 were $37^{\circ}C$. The optimum temperature for CMCase and xylanase from Bacillus sp. EFL1 were $50^{\circ}C$. The optimum pH of Bacillus sp. EFL1 xylanase was pH 5.0 but the optimum pH of CMCase from Bacillus sp. EFL1 was pH 6.0. The optimum temperature of CMCase and xylanase from Bacillus sp. EFL2 was $60^{\circ}C$, respectively. The optimum pH of CMCase of Bacillus sp. EFL2 was 5.0, whereas xylanase showed high activity at pH 3.0-9.0. The optimum temperature for CMCase and xylanase of Bacillus sp. EFP3 was $50^{\circ}C$. The optimum pH for CMCase and xylanse was 5.0 and 4.0, respectively. CMCases from Bacillus sp. EFL1, EFL2, and EFP3 were thermally unstable. Although xylanase from Bacillus sp. EFL1 and EFP3 showed to be thermally unstable, xylanase from Bacillus sp. EFL2 showed to be thermally stable. Therefore, Bacillus sp. EFL2 has great potential for animal feed, biofuels, and food industry applications.