• Korean Journal of Materials Research
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• v.8 no.9
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• pp.797-801
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• 1998

The cure kinetics for diglycidyl ether of bisphenol A(DGEBA)/4, 4'-methylene dianiline(MDA) system with or without lOphr of phenyl glycidyl ether(PGE)-acetamide(AcAm) was studied by autocatalytic cure expression. On the dynamic DSC curves, the exothermic peak temperature and the onset temperature of reaction decreased with the addition of PGE-AcAm. Regardless of the addition of PGE-AcAm, the shape of the conversion curve showed sigmoid, and this meant that DGEBA/MDA and DGEBA/MDA/PGE-AcAm systems followed autocatalytic cure reaction. When PGE-AcAm was added to DGEBA/MDA system, the cure rate increased about 1.2~1.4 times due to the catalytic role of hydroxyl groups in PGE-AcAm.

• Bulletin of the Korean Chemical Society
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• v.16 no.10
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• pp.988-990
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• 1995

No fluorescence was observed from 1-aryl-4-(pentamethyldisilanyl)buta-1,3-diynes except 1-(1-naphthyl)-4-(pentamethyldisilanyl)buta-1,3-diyne. Irradiation of 1-aryl-4-(pentamethyldisilanyl)buta-1,3-diynes (1) with methanol gives photoaddition products in relatively low yields compared to arylethynyldisilanes which show dual fluorescence. Irradiation of 1 with acetone yields site specific and regioselective 1:1 photoadducts through silacyclopropene intermediates. The triplet excited state of the silacyclopropene reacts with acetone to give addition photoproducts and the triplet energy of the silacyclopropenes lies around 260-286 kJ/mol.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.746-751
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• 2006

The effects of resistant starch (RS) and non-starch polysaccharide (NSP) addition on the properties of hard wheat flour were investigated. Total dietary fiber (TDF) levels of various NSP ranged from 78.3-100.0%, but TDF and RS levels of autoclaved RS3 and cross-linked RS4 were 16.1 and 35.0% and 13.2 and 90.9%, respectively. DF-supplemented flour increased swelling power, but RS4-supplemented flour exhibited the lowest it. Solubility increased with the addition of pectin and RS3, but decreased with the addition of cellulose and RS4. RS-supplemented flour had increased lightness (L), but decreased values of redness (a) and yellowness (b). RS3 and pectin increased the dough development time, but RS4, cellulose, and chitosan decreased it. The water absorptions of pectin- and RS4-supplemented flours increased, however the dough stability decreased. The initial pasting temperatures of RS- and NSP-supplemented flours increased regardless of amount added, but the maximum peak viscosity decreased for all except the pectin-supplemented flour.

• Elastomers and Composites
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• v.43 no.4
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• pp.281-287
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• 2008

Using solid state $^{13}C$ NMR, polybutadiene rubber vulcanizates were qualitatively and quantitatively analyzed. In the filled conventional system of BR vulcanizate accelerated with TBBS, addition to the olefinic double bond and substitution in the $\alpha$ position to the double bond occurred simultaneously. Also the latter $\alpha$ substitution reaction was faster than the former addition reaction at initial reaction time. In addition, it was suggested that double bond-addition-polysulfide structures might be modified into 5-membered and 6-membered cyclic structures in overcure time. These chain modifications were correlated with the decrease in the chemical crosslink density in overcure time.

• Journal of the Korean Chemical Society
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• v.25 no.6
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• pp.390-393
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• 1981

Eight new compounds were prepared by the addition reaction of thioglycolic acid to ${\beta}$-nitrostyrene and its derivatives. s-[2-Nitro-1-phenylethyl]-thioglycolic acid; s-[2-nitro-1-(p-methyl)phenylethyl]-thioglycolic acid; s-[2-nitro-1-(p-methoxy)phenylethyl]-thioglycolic acid; s-[2-nitro-1-(p-chloro)phenylethyl]-thioglycolic acid; s-[2-nitro-1-(p-bromo)phenylethyl]-thioglycolic acid; s-[2-nitro-1-(p-nitro)phenylethyl]-thioglycolic acid; s-[2-nitro-1-(3-methoxy-4-ethoxy)phenylethyl]-thioglycolic acid; s-[2-nitro-1-(3,4,5-trimethoxy)phenylethyl]-thioglycolic acid; The structure of these compound were identified by elemental analysis, UV, IR and NMR spectral data.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.429-434
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• 2012

A kind of Antihistamines, Azelastine HCl which known as modern H1-blockers, was synthesized by four step process using phthalic anhydride, 4-chlorophenylacetic acid, hydrazine 2HCl. The first step was the reaction of removing carboxyl group and hydroxyl group and the second step was saponification of 3-(4-chlorobenzylidene)phthalide. The third step was the nucleophilic addition reactions of primary amines and the fourth step was addition reaction of N-methyl-1-aza-bicyclo[3,2,0]heptane to 4-(4-chlorobenzyl)-1-(2H)phthalazinone. As a result, product was analyzed by FT-IR and $^1H$-NMR and could be obtained with a yield of 80%.

• Applied Chemistry for Engineering
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• v.4 no.3
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• pp.569-575
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• 1993

The addition of Sn to Pt/${\gamma}$-$A1_2O_3$ catalyst greatly enhanced the activity and decreased the deactivation rate for the dehydrocyclization of paraffins. For the dehydrocyclization of n-octane, there appeared to be an optimal ratio of Pt:Sn=1:4 for 0.75 wt% Pt/${\gamma}$-$A1_2O_3$ catalyst. The addition of K to Pt/${\gamma}$-$A1_2O_3$ also produced a similar effect on the dehydrocyclization of n-hexane. In the case of n-octane, the addition of K led to a less selective catalyst.

• Journal of Powder Materials
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• v.4 no.4
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• pp.283-290
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• 1997

$Ti_5Si_3$ intermetallics containing 0-6 wt% of Cu were made by reactive sintering (RS) under vacuum using elemental powder mixtures (Process 1), electro-pressure sintering (EPS) using RS'ed materials (Process2), and EPS using elemental powder mixtures (Process 3). Relatively low dense titanium silicides were gained by process 1, in which porosity decreased with increasing Cu content. For example, porosity changed from 42 to 19.4% with the increase in Cu content from 0 to 6 wt%, indicating that Cu is a useful sintering aid. The titanium silicides fabricated by Process 2 had a higher density than those by Process 1 at given composition, and porosity decreased with increasing Cu content. For example, porosity decreased from 38 to 6.8% with the change in Cu content from 0 to 6 wt%. A high dense titanium silicides were obtained by Process 3. In this Process, porosity decreased a little by Cu addition, and was almost insensitive to Cu content. Namely, about 9 or 7% of porosity was shown in 0 or 1-6 wt% Cu containing silicides, respectively. The hardeness increased by Cu addition, and was not changed markedly with Cu content for the silicides fabricated by Process 3. This tendency was considered to be resulted from porosity, hardening of grain interior by Cu addition, and softening of grain boundary by Cu-base segregates. All these results suggested that EPS using elemental powder mixtures (Process 3) is an effective processing method to achieve satisfactorily dense titanium silicides.

• Bulletin of the Korean Chemical Society
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• v.20 no.10
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• pp.1177-1180
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• 1999

The ab initio SCF MO and density functional theory (DFT) studies are carried out on the electrophilic (1a) and electron transfer (1b) addition reactions to the vinyl double bond of aryl vinyl sulfides and ethers. In the electrophilic addition processes, a double bond shift from C3 = C4 to X = C3 occurs with occupation number (1.97) close to the normal two. Due to this shift direct conjugation between the cationic center, X = S or O, and the para electron-donor substituent becomes impossible so that the reaction energies (or log K) are correlated with σ rather than σ+. By contrast, radical cation formation leads to delocalization of the SOMO, a lone-pair πorbital on X, with four major resonance structures in which cationic charge as well as spin density is delocalized over C4 , X and C7 atoms. As a result, partial πbonds are formed over C1 -X and C3 - C4 with occupation numbers (0.82) lower than one. In two of the cannonical structures, III(Ⅹ) and III(X+), direct conjugation between the cationic center, X, and the para substituent is achieved so that a better correlation with σ+ rather than σis obtained. The SCF MO energies at the HF/3-21G* and HF/6-31G* levels lead to very much inferior Hammett correlations in the σ/ σ+ diagnostic criterion. In contrast, the ρvalues evaluated with the DFT energies can give reliable diagnostic distinction between the two addition mechanisms.

• The Korean Journal of Food And Nutrition
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• v.34 no.4
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• pp.321-330
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• 2021

The purpose of this study was to investigate the quality characteristics of bread made with 1%, 3%, 5%, and 7% of Bigeumdo Seomcho powder (Spinacia oleracea L.). The pH of dough and bread decreased as the amount of addition increased; 7% indicated the lowest. The moisture level correlated negatively with the powder addition, but the difference was not statistically meaningful (p<0.05). As the amount of addition was increased, the intensity of color increased but the volume decreased. The brightness and redness of the bread decreased as the amount of addition increased. The volume, specific volume, and baking loss rate correlated negatively with the powder addition. Regarding springiness, cohesiveness, and gumminess, the experiment group was higher than the control group and they lowered as the addition amount increased. The brittleness showed positive correlation with the addition amount. Out of the amino acids of bread, glutamic acid showed the highest value as the amount of addition was increased. Overall, it is possible to produce bakery bread using functional ingredients.