• Journal of Korean Public Health Nursing
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• v.31 no.2
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• pp.272-283
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• 2017

Purpose: This descriptive study compared changes in life style and health perceptions before and after the onset of coronary heart disease in 100 patients. Methods: Data were from May to July in 2016 through questionnaires and medical records. The collected data were analyzed by a $x^2$ test, and paired t-test using SPSS 12.0. Results: After the onset of heart disease, significant decreases were observed in smoking ($x^2=17.21$, p<.001) and drinking ($x^2=43.56$, p<.001), while exercise increased significantly ($x^2=32.77$, p<.001). Appetite, stress and health state were significantly decreased after the onset of heart disease (t=3.18, p=.002, t=3.55, p=.001, t=4.43, p<.001), and knowledge about disease was significantly increased after the onset of heart disease (t=-13.66, p<.001). Conclusion: The results of this study indicate that continuous follow-up management programs including smoking and drinking cessation, exercise, appetite and stress management should be developed and implemented for Coronary Heart Disease with PCI.

• Journal of Hydrogen and New Energy
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• v.22 no.3
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• pp.326-332
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• 2011

The authors examined the effects of operating parameters on the $H_2$ production by dark fermentation of the wastewater generated from food waste recycling facilities, in short "food waste wastewater (FWW)". Central composite design based response surface methodology was applied to analyze the effect of initial pH (5.5-8.5) and substrate concentration (2-20 g Carbo. COD/L) on $H_2$ production. The experiment was conducted under mesophilic ($35^{\circ}C$) condition and a heat-treated ($90^{\circ}C$ for 20min)anaerobic digester sludge was used as a seeding source. Although there was a little difference in carbohydrate removal, $H_2$ yield was largely affected by the experimental conditions, from 0.38 to 1.77 mol $H_2$/mol $hexose_{added}$. By applying regression analysis, $H_2$ yield was well fitted based on the coded value to a second order polynomial equation (p = 0.0243): Y = $1.78-0.17X_1+0.30X_2+0.37X_1X_2-0.29X_1{^2}-0.35X_2{^2}$, where $X_1$, $X_2$, and Y are pH, substrate concentration (g Carbo. COD/L), and hydrogen yield (mol $H_2$/mol $hexose_{added}$), respectively. The 2-D response surface clearly showed a high inter-dependency between initial pH and substrate concentration, and the role of these two factors was to control the pH during fermentation. According to the statistical optimization, the optimum condition of initial pH and substrate concentration were 7.0 and 13.4 g Carbo. COD/L, respectively, under which predicted $H_2$ yield was 1.84 mol $H_2$/mol $hexose_{added}$. Microbial analysis using 16S rRNA PCR-DGGE showed that $Clostridium$ sp. such as $Clostridium$ $perfringens$, $Clostridium$ $sticklandii$, and $Clostridium$ $bifermentans$ were main $H_2$-producers.

• Macromolecular Research
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• v.15 no.4
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• pp.302-307
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• 2007

The living radical polymerization of methyl methacrylate (MMA) by atom transfer radical polymerization, (ATRP) employing a $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine (PyP) catalytic system (X=Cl, Br), was investigated using several initiators and solvents at various temperatures. Most of the polymerizations with the PyP ligand were well controlled, with a linear increase in the number average molecular weights ($M_n$) vs. conversion, with relatively low molecular weight distributions ($M_w/M_n=1.2-1.4$) throughout the reactions. The measured weights matched those of the predicted values. The ethyl-2-bromoisobutyrate (EBriB) initiated ATRP of MMA, with the $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine catalytic system (X=Cl, Br), was better controlled in p-xylene at $80^{\circ}C$ than the other solvents used in this study.

• International journal of advanced smart convergence
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• v.9 no.1
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• pp.1-9
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• 2020

This study was conducted to investigate the effects of computer attitudes such as anxiety, confidence, preference, usefulness, and computer literacy on their critical thinking ability, targeting college students at unspecified university universities. The period of data collection was from January 10, 2020 to January 17, 2020. A total of 213 people participated in the study. For data analysis, SPSS 18.0 was used for frequency analysis, Pearson correlation, x2 square, and simple regression analysis. As a result of the analysis, the difference of interests under the statistical significance level among general characteristics was Gender (x²=55.7^***, p<0.001), Age (x²=407.5^***, p<0.001), Resident (x²=127.5^***, p<0.001) Family (x²=289.4^***, p<0.001). In the simple regression analysis, computer liking (t=2.102, p<0.05) and computer use ability affected Truth seeking (t=-6.319, p<0.01), computer use ability was affecting analyticity (t=-5.630, p<0.01), computer use ability was affecting systematicity (t=-2.545, p<0.05), computer use ability was affecting maturity under statistical significance (t=-2.583, p<0.05). In conclusion, this study suggests that computer liking and computer use ability affect the sub-factor components of critical thinking disposition, truth seeking, analyticity, systematicity, and maturity, therefore the emphasis of this study is to emphasize that it is desirable to use the computer as a medium of learning based on computer literacy rather than worrying about excessive computer use.

• Bulletin of the Korean Mathematical Society
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• v.35 no.2
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• pp.319-324
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• 1998

The equation AX = BX implies $A^*X\;=\;B^X$ when A and B are normal (Fuglede-Putnam theorem). In this paper, the hypotheses on A and B can be relaxed by usin a Hilbert-Schmidt operator X: Let A be p-quasihyponormal and let $B^*$ be invertible p-quasihyponormal such that AX = XB for a Hilbert-Schmidt operator X and $|||A^*|^{1-p}||{\cdot}|||B^{-1}|^{1-p}||\;{\leq}\;1$.Then $A^*X\;=\;XB^*$.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.253-261
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• 2005

Catalytic wet oxidation of ppm levels of trichloroethylene (TCE) in water has been conducted using $TiO_2$-supported cobalt oxides at a given temperature and weight hourly space velocity. 5% $CoO_x/TiO_2$ might be the most promising catalyst for the wet oxidation at $36^{\circ}C$ although it exhibited a transient behavior in time on-stream activity. Not only could the bare support be inactive for the wet decomposition reaction, but no TCE removal also occurred by the process of adsorption on $TiO_2$ surface. The catalytic activity was independent of all particle sizes used, thereby representing no mass transfer limitation in intraparticle diffusion. Characterization of the $CoO_x$ catalyst by acquiring XPS spectra of both fresh and used Co surfaces gave different surface spectral features of each $CoO_x$. Co $2p_{3/2}$ binding energy of Co species exposed predominantly onto the outermost surface of the fresh catalyst appeared at 781.3 eV, which is very similar to the chemical states of $CoTiO_x$ such as $Co_2TiO_4$ and $CoTiO_3$. The spent catalyst possessed a 780.3 eV main peak with a satellite structure at 795.8 eV. Based on XPS spectra of reference Co compound, the TCE-exposed Co surfaces could be assigned to be in the form of mainly $Co_3O_4$. XRD measurements indicated that the phase structure of Co species in 5% $CoO_x/TiO_2$ catalyst even before reaction is quite comparable to the diffraction lines of external $Co_3O_4$ standard. A model structure of $CoO_x$ present on titania surfaces would be $Co_3O_4$, encapsulated in thin-film $CoTiO_x$ species consisting of $Co_2TiO_4$ and $CoTiO_3$, which may be active for the decomposition of TCE in a flow of water.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.5
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• pp.210-213
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• 2011

Glass-ceramics composed of $5Na_2O-36CaO-10TiO_2-xP_2O_5$ could be obtained with $P_2O_5$ content as following procedure: 1) leaching out $Ca_3(PO_4)_2$ crystals between $Ca_3(PO_4)_2$ and $NaTi_2(PO_4)_3$ selectively in 1 N HCl solution for 2 days, and 2) exchanging $Na^+$ ion to $Ag^+$ ion in Ag($NO_3$) solution for 1 day. Scanning electron microscope (SEM) and X-rat diffractometer (XRD) were measured to verify the proper synthesis of glass-ceramics. And anti-bacteria test was accomplished using Staphylococus aureus bacteria. In the results of anti-bacteria test, the bacteria were died perfectly after 3 hours.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.3
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• pp.207-214
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• 1995

'Ihis experiment was canied out to investigate the feed intake, chewing activities and ruminal characteristics by change in roughage intake and concentrate feeding amount with 15 Holstein cows. 1. DM intake of cow fed rice straw, corn silage and grass hay was 4.97, 5.47 and 5.60% of metabolic weight, respectively, and that by kg increase of concentrate was decreased by 0.330, 0.294 and 0.461 kg, respectively. 2. RVI of rice straw, com silage and grass hay was 98.3, 93.7 and 87.1 respectively, and correlations between RVIfl) and concentrate level@) were the following; $Y_1$(rice straw) = 99.4543 - 5.9759X + 0.0230$X^2$ This experiment was carried out to investigate the feed intake, chewing activities and ruminal characteristics by change in roughage intake and concentrate feeding amount with 15 Holstein cows. 1. DM intake of cow fed rice straw, corn silage and grass hay was 4.97, 5.47 and 5.60% of metabolic weight, respectively, and that by kg increase of concentrate was decreased by 0.330, 0.294 and 0.461 kg, respectively. 2. RVI of rice straw, com silage and grass hay was 98.3, 93.7 and 87.1 respectively, and correlations between RVI(Y) and concentrate level(X) were the following; $Y_1$(rice straw) = 99.4543 - 5.9759X + 0.0230$X^2$ $Y_2$(com silage) = 88.7601 - 2.9000X - 0.2111$X^2$ $Y_3$(grass hay) = 95.1515 - 6.3096X + 0.0873$X^2$ 3. Average ruminal pH in rice straw feeding group was the highest and correlations between ruminal pH(Y) and concentrate level(X) were the following; $Y_1$ = 7.0920 - 0.0309X - 0.0023$X^2$ $Y_2$ = 6.5000 - 0.0516X + 0.0002$X^2$ $Y_3$= 6.7666 - 0.0072X - 0.0044$X^2$ 4. Average ruminal $NH_3-N$ concentration in forage hay feeding group was the highest and correlations between ruminal $NH_3-N$ concentration(Y) and concentrate level(X) were the following. $Y_1$ = 3.3777 - 0.0587X + 0.0682$X^2$ $Y_2$ = 4.2765 + 0.5921X + 0.0181$X^2$ $Y_3$= 5.3634 - 0.4203X + 0.0223$X^2$ 5. Ruminal VFA wncentmtion in corn silage feeding group was the highest.

• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.702-709
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• 1999

The present study was performed to elucidate the effects of extracellular $Ca^{2+}$ on contractile responses in isolated porcine coronary artery ring using by perivascular nerve stimulation (PNS). Especially, the study was focused on the source of $Ca^{2+}$ on $P_{2X}$-purinoceptor mediated muscle contraction which one of $P_2$-purinoceptor subtypes. The following results can be drawn from these studies : 1. The phasic contractions induced by PNS were inhibited with muscarinic receptor antagonist, atropine ($10^{-6}M$). 2. The phasic contractions induced by PNS were significantly inhibited by sequential treatment with atropine and adrenergic neural blocker, guanethidine ($10^{-6}M$). 3. The phasic contractions induced by PNS were inhibited with $P_{2X}$-purinoceptor desensitization by repetitive application of $\alpha$,$\beta$-Me ATP ($10^{-4}M$). 4. The phasic contractions induced by PNS were so weakened in calcium-free medium. 5. The phasic contractions induced by PNS were inhibited with calcium channel blocker, verapamil ($10^{-6}{\sim}5{\times}10^{-6}M$). 6. The phasic contractions induced by PNS on pretreated with verapamil ($10^{-6}{\sim}5{\times}10^{-6}M$) were not changed by $\alpha$,$\beta$-Me ATP ($10^{-4}M$). These results demonstrate that the neurogenic phasic contractions induced by PNS are due to adrenergic-, cholinergic- and $P_{2X}$-purinergic receptors and the origin of $Ca^{2+}$ on $P_{2X}$-purinoceptor mediated muscle contraction is extracellular $Ca^{2+}$ through plasmalemmal $Ca^{2+}$ channels.

• Journal of the Korean Mathematical Society
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• v.57 no.3
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• pp.747-775
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• 2020

In this work we investigate the nonlocal elliptic equation with critical Hardy-Sobolev exponents as follows, $$(P)\;\{(-{\Delta}_p)^su={\lambda}{\mid}u{\mid}^{q-2}u+{\frac{{\mid}u{\mid}^{p{^*_s}(t)-2}u}{{\mid}x{\mid}^t}}{\hspace{10}}in\;{\Omega},\\u=0{\hspace{217}}in\;{\mathbb{R}}^N{\backslash}{\Omega},$$ where Ω ⊂ ℝ^N is an open bounded domain with Lipschitz boundary, 0 < s < 1, λ > 0 is a parameter, 0 < t < sp < N, 1 < q < p < p^∗_s where $p^*_s={\frac{N_p}{N-sp}}$, $p^*_s(t)={\frac{p(N-t)}{N-sp}}$, are the fractional critical Sobolev and Hardy-Sobolev exponents respectively. The fractional p-laplacian (-∆_p)^su with s ∈ (0, 1) is the nonlinear nonlocal operator defined on smooth functions by $\displaystyle(-{\Delta}_p)^su(x)=2{\lim_{{\epsilon}{\searrow}0}}\int{_{{\mathbb{R}}^N{\backslash}{B_{\epsilon}}}}\;\frac{{\mid}u(x)-u(y){\mid}^{p-2}(u(x)-u(y))}{{\mid}x-y{\mid}^{N+ps}}dy$, x ∈ ℝ^N. The main goal of this work is to show how the usual variational methods and some analysis techniques can be extended to deal with nonlocal problems involving Sobolev and Hardy nonlinearities. We also prove that for some α ∈ (0, 1), the weak solution to the problem (P) is in C^1,α(${\bar{\Omega}}$).