• Journal of the Korea Concrete Institute
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• v.16 no.4 s.82
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• pp.549-555
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• 2004

Cement of three alkalinities (equivalent alkalinities of 0.36,0.52 and 0.97) was employed in fabricating a set of classical G109 type specimens. To-date, these have been subjected to a one week wet-one week dry cyclic pending using 15 w/o NaCl solution. At the end of the dry period, potential and macro-cell current were measured to indicate whether the top reinforcing steel was in the passive or active state. Once this bar became active, the specimen was autopsied and the extent of corrosion was documented. Subsequent to visual inspection, concrete powder samples were collected from the upper region of the top rebar trace; and at a certain times concrete cores were taken from non-reinforced specimens. Using these, determinations were made of (1) critical chloride concentration for corrosion initiation ($Cl_{th}^-$), (2) effective chloride diffusion coefficient ($D_e$), and (3) pore water alkalinity ($[OH^-]$). The pore water alkalinity was strongly related to the alkali content of cement that was used in the mix. The chloride concentration, ($Cl^-$), was greater at active than at passive sites, presumably as a consequence of electro migration and accumulation of these species at active site subsequent to corrosion initiation. Accordingly, ($Cl^-$) at passive sites was considered indicative of the threshold concentration fur corrosion initiation. The $Cl_{th}^-$ was increased with increasing Time-to-corrosion ($T_i$). Consequently, the HA(High Alkalinity) specimens exhibited the highest $Cl_{th}^-$ and the NA(Normal Alkalinity) was the least. This range exceeds what has previously been reported in North America. In addition, the effective diffusion coefficient, $D_e$, was about 40 percent lower for concrete prepared with the HA cement compared to the NA and LA(Low Alkalinity) ones.

• Environmental Engineering Research
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• v.22 no.2
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• pp.149-156
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• 2017

Chromium(III) recovery from tanning wastewater by means of adsorption on activated carbon and elution with sulfuric acid was studied. Tests were carried out at laboratory scale on an effluent of industrial origin. Initially, proteinaceous materials and fats were separated via sieving followed by ultrafiltration. The chemical composition of the sample thus precleansed was (in g/L): 1.09 chromium(III); 10.36 sulfate; 11.10 sodium; 9.57 chloride; 0.40 proteinaceous materials; and 0.20 fats. Adsorptions were made at 20, 30, and $40^{\circ}C$, establishing what temperature favored chromium(III) uptake. At $40^{\circ}C$, the maximum cation fixation was 40.2 mg/g, and the lowest content in an equilibrium solution was 3.9 mg/L. As regards sodium, chloride, and sulfate, the concentrations before and after the treatment were similar. Likewise, it was found that protons were also retained, modifying the pH of the liquid medium. Adsorption isotherms were analyzed using the Langmuir, Temkin, and Freundlich models. Finally, the extraction of the adsorbed tanning agent with sulfuric acid was evaluated. A recovery of 96.5% was achieved with 0.9 N at $70^{\circ}C$ (13.23 g/L $Cr^{3+}$; 42.98 g/L sulfate; and 0.40 g/L NaCl).

• Journal of the Korean Ceramic Society
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• v.33 no.3
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• pp.313-320
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• 1996

We have fabricated an in-plane aligned a-axis oriented YBa2Cu3O7-x (a-YBCO) thin film on a LaSrGaO4(100) substrate with a PrBa2Cu3O7-x(PBCO) template layer by two step plused laser deposition using 308 nm XeCl excimer laser. A YBCO layer and PBCO layer grown at low temperatures were used as template layers. We have investigated the effect of the deposition temperature of template layers on the superconducting and struc-tural properties of in-plane aligned a-YBCO thin films. An optimal deposition temperature of the PBCO template layers was 630. In-plane aligned a-YBCO thin films showed an anisotropy ratio in resistivity of 11.5 and a zero resistance temperature of 88 K.

• Journal of information and communication convergence engineering
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• v.4 no.1
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• pp.18-22
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• 2006

A small-sized gas identification system has been fabricated and characterized using an integrated gas sensor array and artificial neural-network. The sensor array consists of four thick-film oxide semiconductor gas sensors whose sensing layers are $In_{2}O_{3}-Sb_{2}O_{5}-Pd-doped\;SnO_2$ + Pd-coated layer, $La_{2}O_{5}-PdCl_{2}-doped\;SnO_2,\;WO_{3}-doped\;SnO_{2}$ + Pt-coated layer and $ThO_{2}-V_{2}O_{5}-PdCl_{2}\;doped\;SnO_{2}$. The small-sized gas identification instrument is composed of a GMS 81504 containing an internal ROM (4k bytes), a RAM (128 bytes) and four-channel AD converter as MPU, LEDs for displaying alarm conditions for three gases (liquefied petroleum gas: LPG, liquefied natural gas: LNG and carbon monoxide: CO) and interface circuits for them. The instrument has been used to identify alarm conditions for three gases among the real circumstances and the identification has been successfully demonstrated.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.5
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• pp.598-605
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• 2005

Effects of chitosan-ascorbate(CA) and calcium lactate(CL) on fermentation and quality of squid sikhae were investigated CA and LA were added at $0.5\%$ (designated CA1 and CL1) and $1.0\%$(CA2 and CL2) concentrations, respectively and fermented for 12 days at $10^{\circ}C$. pH of CA-added sikhae was higher than that of control, while acidity of the former was lower than that of the latter. During 12 days of fermentation, CA-added sikhae showed higher protease activity than control by $2.3\~2.6$ times and CL-added sikhae by $2.8\~3.6$ times. At 12 days of fermentation, CA-added sikhae revealed higher protease activity than control by $1.2\~1.4$ times and CL-added sikhae by $1.5\~1.9$ times. CA-added sikhae also showed higher amino-nitrogen content than control by $1.4\~1.7$ times and CL-added sikhae by $1.9\~3.5$ times. In comparison of CA1 with CA2, CA2 showed all higher pH, protease and amylase activity, and amino-nitrogen content than CA1. In analysis of electrophoresis, molecular weights of major proteins in ~w squid were $116.9\~119.0$, 96.5 and 59.3kDa. However, after fermentation for 12 days, a protein band of 119.0kDa disappeared but a new protein band with below 14 kDa appeared in sikhae, especially CA-added sikhae. In sensory evaluation, the intensity of sour taste was the highest for control and the lowest for CA2. Softness of squid was the highest for control and the lowest for CA2. Overall acceptability was the best for CA2. In conclusion, these results suggest use of $1\%$ CA in sikhae preparation as addition of CA(CA2) increased the protease and amylase activity, nitrogen content of amino form, sensory acceptability as well as shelf-life of sikhae.

• Journal of environmental and Sanitary engineering
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• v.12 no.1
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• pp.25-37
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• 1997

The synthesis of high purity and ultra-fine $BaTiO_{3}$ by precipitation with gaseous $NH_{3}$ as precipitator was investigated to find an alternative process to solve various problems of present wet methods. This study consisted of two parts ; synthesis of $BaTiO_{3}$ precipitation with gaseous $NH_{3}$ and test of electrical property for the $La_{2}O_{3}$ doped $BaTiO_{3}$. The proper condition for the synthesis of $BaTiO_{3}$ by precipitation with gaseous $NH_{3}$ is as follows. The pH was 9.0. $H_{2}O_{2}$ mole ratio to $TiCl_{4}$ was 10. $NH_{3}$ gas follow rate did not influence the synthesis of $BaTiO_{3}$. The calcination temperature of $BaTiO_{3}$ was $300^{\circ}C$. Also, the synthesis of $La_{2}O_{3}$-doped $BaTiO_{3}$ was tested through the wet process. Under these condition, the shape of prepared $BaTiO_{3}$ powder was spherical type and the size of that was about $0.2{\mu}m$. After the powder was pressed, this green body was sintered at the $1300^{\circ}C$. Under these conditions, the water absorptance and the density of the obtained sintered body were below 0.04 %, 5.2 g/$cm^{3}$, respectively. Also the grain size of that was about $10{\mu}m$ and it was similar to commercial product.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.101-108
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• 1996

The dynamic surface tension of GL12 (easily biodegradable nonionic surfactant and mild to skin), LAS and SLES aqueous solutions and that of mixed surfactant systems were measured by the maximum bubble pressure method at different mixing ratios. The effects of various salt such as NaCl, CsCl and urea on the dynamic surface tension of mixed surfactant systems were also studied. The dynamic surface tension of GL12 was not influenced by the presence of salts. On the contrary, the dynamic surface tensions of anionic surfactants (LAS and SLES) were significantly affected by the salts. In the mixed surfactant systems, the effect of salt increased as the composition of anionic LAS or SLES increased in the GL12/LAS and GL12/SLES mixtures.

• Macromolecular Research
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• v.15 no.3
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• pp.221-224
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• 2007

A silica-magnesium bisupport (SMB) was prepared by a sol-gel method for use as a support for a metal-locene/Ziegler-Natta hybrid catalyst. The prepared $rac-Et(Ind)_2ZrCl_2/TiCl_4$/MAO(methylaluminoxane)/SMB catalyst was applied to the copolymerization of ethylene with l-hexene using a variable triethylaluminum (TEA)/transition-metal (Ti) ratio and fixed MAO/transition-metal (Zr) ratio. The effect of the Al(TEA)/Ti ratio on the physical properties and chemical composition distributions (CCDs) of the ethylene-hexene copolymers produced by the hybrid catalyst was investigated. In the ethylene-hexene copolymers, two melting temperatures attributed to the metal-locene and Ziegler-Natta catalysts were clearly observed. The number of CCD peaks was increased from six to seven and the temperature region in which the peaks for the short chain branches of the ethylene-hexene copolymer were distributed became lower as the Al(TEA)/Ti ratio was increased from 300 to 400. Furthermore, the temperature regions corresponding to the lamellas in the copolymer became lower and those corresponding to the small lamellas in the copolymer became higher as the Al(TEA)/Ti ratio was increased from 300 to 400. In the copolymer produced with Al(TEA)/Ti = 500, however, only four CCD peaks were observed and the short chain branches were poorly distributed.

• Bulletin of the Korean Chemical Society
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• v.29 no.2
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• pp.372-376
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• 2008

The hydrolysis of gallium(III) has been studied using potentiometric techniques under physiological conditions of temperature 37 C and ionic strength 0.15 moldm-3 NaCl and at different metal ion concentrations. Changes in pH were monitored with a glass electrode calibrated daily in hydrogen ions concentrations. The titration data within the pH range of 2.5-9.99 were analyzed to determine stability constants of hydroxide species using the SUPERQUAD program. Several different species were considered during the calculation procedure and the following hydroxides have been characterized: Ga(OH)3, Ga(OH)4- Ga3(OH)112-, Ga4(OH)11+ and Ga6(OH)153+. Speciation calculations based on the determined constants were then used to simulate the species distribution.

• The Research Journal of the Costume Culture
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• v.17 no.3
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• pp.407-423
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• 2009

The purpose of this study is to analyze Bakst's stage costume illustrations for Ballets Russes. The Russian Ballets has renown in the West since the early 20th century. Diaghilev first made his name as the organizer of art exhibitions in Russia and Western Europe. Diaghilev risked presenting only ballets in 1909, that time Bakst designed $Sch{\acute{e}}h{\acute{e}}razade$, L'Oiseau de Feu and Le Carnival. $Sch{\acute{e}}h{\acute{e}}razade$ was something new which overwhelmed the French people by then. It was seen to be the achievement of Wagner's idea where all the elements; the music, the design, the choreography, and the dancing fused into a perfect whole. The entire production was a hitherto unseen harmony of colors, sounds and movements. For the 1911 season in Paris, Diaghilev planned to present six new ballets and Bakst designed four ballets. Bakst's design of the set and the costume greatly shocked the audience. His "Originality" shines on the fact that he introduced a palette of colors in theater for the first time in history. He used a magic of colors to suggest the secret meaning of what was happening on the stage. The results can be divided into three distinct characteristics. First, oriental designs such as $Cl{\acute{e}}op{\hat{a}}tre$, $Sch{\acute{e}}h{\acute{e}}razade$, L'Oiseau de Feu, La $P{\acute{e}}ri$ and Le Dieu Blue with Russian, Indian and Persian traditional design in headdress and accessories ars found. Second, Le Carnival and La Spectre de la Rose used romantic styles with oriental details. Third, Greek chiton and Himation are used in Narcisse, $H{\acute{e}}l{\grave{e}}ne$ de Sparte, $L'Apr{\grave{e}}s-Midi\;d^{\grave{\;}}un$ Faune and Daphnis et $Chlo{\acute{e}}$ inspirde with various colors and geometic patterns. Bakst's orient of lush colored costumes, head dress, cushions, rugs and hangings became the immediate fashion imitated by Parisian couture houses and interior decorators.