• Steel and Composite Structures
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• v.16 no.6
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• pp.611-637
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• 2014

A single plate shear connection, or shear tab, is a very popular shear connection due to its merit in ease of construction and material economy. However, problems in understanding the connection behavior, both in terms of strength and ductility, have been well-documented. Suggestions or design model for single plate connections in AISC Design Manual have been altered several times, with the latest edition settling down to giving designers pre-calculated design strength tables if the connection details agree with given configurations. Results from many full-scale tests and finite element models in the past suggest that shear strength of a bolt group in single plate shear connections might be affected by yield strength of plate material; therefore, this research was aimed to investigate and clarify effects of plate yield strength and thickness on shear strength of the bolt group in the connections, including the validity of using a plate thickness/bolt diameter ratio ($t_p/d_b$) in design, by using finite element models. More than 20 models have been created by using ABAQUS program with 19.0- and 22.2-mm A325N bolts and A36 and Gr.50 plates with various thicknesses. Results demonstrated that increase of plate thickness or plate yield strength, with the $t_p/d_b$ ratio remained intact, could significantly reduce shear strength of the bolt group in the connection as much as 15 percent. Results also confirmed that the $t_p/d_b$ ratio is a valid indicator to be used for guaranteeing strength sufficiency. Because the actual ratio recommended by AISC Design Manual is $t_p/d_b$ + 1.6 (mm) for connections with a number of bolts less than six and plate yield strength in construction is normally higher than the nominal value used in design, it is proposed that shear strength of a bolt group in single plate connections with a number of bolts equal or greater than seven be reduced by 15 percent and the $t_p/d_b$ ratio be limited to 0.500.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1256-1267
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• 2011

Two experiments were conducted to determine the effects of dietary lysine and energy level on performance and apparent total tract digestibility (ATTD) of nutrients in weanling pigs. In Exp. 1, a total of 288 weaned pigs (initial BW $5.77{\pm}0.85\;kg$) were randomly allotted to 4 treatments (4 replicates per treatment with 18 pigs in each replicate). Experimental diets were fed in the 3 phases: phase I (d 0 to 7), phase II (d 8 to 14) and phase III (d 15 to 28). Isocalorific diets (3,450 kcal/kg) with incremental lysine levels (Phase I: 1.51, 1.61, 1.71 and 1.81; Phase II: 1.35, 1.46, 1.56 and 1.66; Phase III: 1.18, 1.28, 1.39 and 1.49% lysine respectively for T1, T2, T3 and T4) were used as treatments. An increase in the dietary lysine levels linearly improved (p<0.05) the ADG and G:F during phases I, II and III as well as overall study period. The ATTD of DM (d 7 and 28) and CP (d 7, 14 and 28) were linearly improved (p<0.05) with increasing dietary lysine levels. ATTD of ash, Ca and P were not affected by dietary lysine level. In Exp. 2, 64 weanling pigs (initial BW $4.79{\pm}0.79\;kg$) were randomly allotted to 4 treatments (4 replicates per treatment with 4 pigs in each replicate) in a $2{\times}2$ factorial arrangement on the basis of BW. Effects of two levels of energy (high, 3,450 or low, 3,350 kcal/kg) and lysine (high or low; 1.70 or 1.50, 1.55 or 1.35 and 1.40 or 1.20% in phase I, II and III diets, respectively) on performance and ATTD of nutrients were investigated. High energy and lysine diets improved ADG (p<0.05) in pigs during phase I, II and III and overall period (p<0.001), while G:F increased (p<0.05) during phase I and overall period. Pigs fed high lysine diets consumed more (p<0.05) feed during phase III and overall period. Additionally, pigs fed high energy diets had greater (p<0.05) ATTD of GE (d 7 and 14), CP (d 7 and 28) and DM (d 28); whereas, pigs fed high lysine diets had greater (p<0.05) ATTD of GE and CP during d 7, 14 and 28. ATTD of ash, Ca and P remained unaffected (p>0.05) by dietary energy and lysine level. However, there was no energy${\times}$lysine interaction for any of the measured variables. Results obtained in present study suggested that high energy and lysine level improve the growth performance and ATTD of nutrients in weanling pigs.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1687-1697
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• 2020

This study is a comparative descriptive research that identifies the degree and difference of the brain education meditation program from participation stress(physical stress, psychological stress), depression, resilience(self-control ability, interpersonal relationship ability, and positive) for middle-aged women. The subjects were 26 middle-aged women who participated in the brain education meditation program at the D metropolitan city D center for more than a year, 29 middle-aged women did not participate in the brain education meditation program and a total of 55 middle-aged women collected for three weeks from November 4 to 22, 2019. Data analysis fesult that the participating groups in brain education meditation programs differ statistically significantly in physical stress(t=2.549, p=.014), psychological stress(t=2.352, p=.022), self-control ability(t=-2.219, p=.031) and positive(t=-2.387, p=.021), which are higher factors in resilience than non-participating groups. In other words, brain education meditation program participants scored lower physical and psychological stress scores than nonparticipating groups, with higher self-control ability and positive scores. Therefore, it is thought that brain education meditation programs can be used as nursing intervention to reduce stress and improve self-control ability and positive in middle-aged women.

• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.695-701
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• 2011

The study was carried out to investigate the effect of lighting regimes on performance and meat quality of broiler. A total of 912 chicks was divided into 2 groups with male (3 replications/group, 34 heads/replication) and female (3 replications/group, 42 heads/replication). Treatments were control (C, natural lighting), T1 treatment (24L), and T2 treatment (1~2d, 24L; 2~4d, 23L+1D; 4~16d, 16L+8D; 16~21d, 18L+6D; 21~42d, 23L+1D) by lighting regimes. Lysine content of male chicken meats at T2 treatment was lower compared to that of other treatments (p<0.05). There was no significant difference in all nonessential amino acid (AA) among treatments. Methionine content of female chicken meats at T2 treatment was lower compared to that of other treatments (p<0.05). The rate of C16:0, C16:1n7, and C18:1n9 of male chicken meat at T2 treatment was higher than that of other treatments (p<0.05), while C18:2n6 was lower at T2 treatment than other treatment (p<0.05). Mono-saturated fatty acid was the highest at T2 treatment, however, polysaturated fatty acid was the lowest at that treatment (p<0.05). There was no considerable difference in fatty acid composition of female chicken meat among treatments. Finally, lighting regime didn' affect on amino acid and fatty acid contents, and used possibly on energy reduction.

• Journal of Microbiology and Biotechnology
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• v.34 no.8
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• pp.1636-1641
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• 2024

A Gram-stain-positive, aerobic, white-coloured, rod-shaped bacteria, designated as a strain dW9^T, was isolated from soil. Strain dW9^T was catalase-positive and oxidase-negative. Strain dW9^T grew at temperature of 20-37℃ and at pH of 5.0-7.0. Phylogenetic and 16S rRNA gene analysis indicated that strain dW9^T belonged to the genus Paenibacillus with its closest relative being Paenibacillus filicis S4^T (97.4% sequence similarity). The genome size of dW9^T was 7,787,916 bp with DNA G+C G+C content of 51.3%. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values of dW9^T with its closest relatives were found to be <22.0% and <74.0%, respectively. The only respiratory quinone was MK-7, and the major fatty acids were antiso-C_15:0 and iso-C_16:0. Overall, the comprehensive taxonomic analysis revealed that strain dW9^T met all the fundamental criteria to be classified as a novel species within the genus Paenibacillus. Accordingly, we propose the name Paenibacillus gyeongsangnamensis sp. nov., with the type strain dW9^T (=KCTC 43431^T =NBRC 116022^T).

• Journal of the Korean Chemical Society
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• v.45 no.5
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• pp.401-412
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• 2001

The geometrical parameters, vibrational frequencies, and dissociation energies for $H_{2n+1}^+$ (n=1~6) clusters have been investigated using high level ab initio quantum mechanical techniques with large basis sets. The equilibrium geometries have been optimized at the self-consistent field (SCF), the single and double excitation configuration interaction (CISD), the coupled cluster with single and double excitation (CCSD), and the CCSD with connected triple excitations [CCSD(T)] levels of theory. The highest levels of theory employed in this study are TZ2P+d CCSD(T) up to $H^+_g$ and TZ2P CCSD(T) for $H_{11}^+$ and $H_{13}^+$. Harmonic vibrational frequencies are also determined at the SCF level of theory with various basis sets and confirm that all the optimized geometries are true minima. The dissociation energies, $D_e$, for $H_{2n+1}^+$ (n=26) have been predicted using energy differences at each optimized geometry and zero-point vibrational energies(ZPVEs) have been considered to compare with experimental dissociation energies, $D_0$.

• Journal of the Korean Ceramic Society
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• v.19 no.2
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• pp.115-120
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• 1982

The main objective of this work was to study the efTect of pressed density of pellets prepared from an oxide powder on their fired density and to prove experimentally the parabolic relationship proposed by FORD. A-I6 and A-J7 alumina powders. which showed quite dlfrerent powder characteristics but were essentially very reactive powders, were employed, and a series of pelIets weIe pressed in a 1l.2mm diameter hardened steel die with a hydraulic press and a mechanically operated press in order to obtain a wide range of pressed demity. Density ranges from 35 to 65 % theoretical for A-16, and 46 to 66 % theoretical far A-17 were obtained and the highest pressed density achieved using lubricant was 67.8 % theoretical. CompactlOn mechanisms for A-16 and A-I 7 were deduced. Several plots of ($D_F$-$D_P$) against DpjDT showed reasonable parabola and temperature dependence and the maximum density increase occurred when the pressed density was approximately 50% theoretical. The parabolic relationship was confirmed by linear plot of ($D_F$-$D_P$) against (1-$\frac{D_P}{D_T})$).

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.10
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• pp.1567-1574
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• 2001

In order to operate an RPV safely it is necessary to keep the pressure-temperature (P-T) limit during the heatup and cooldown process. While the ASME Code provides the P-T limit curve for safe operation, this limit curve has been prepared under conservative assumptions In this paper the effects of conservative assumptions involved in the P-T limit curve specified in the ASME Code Sec. XI were investigated. Three different parameters the crack depth the cladding thickness and the cooling rate, were reviewed based on 3-D finite element analyses. Also the constraint effect on P-T limit curve generation was investigated based on J- T approach. It was shown that the crack depth and the constraint effect change the safe region in P-T limit curve significantly Therefore it is recommended to prepare a more precise P-T limit curve based on finite element analysis to obtain P-T limit for safe operation of an RPV.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.168-171
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• 1988

The p-n homo junction diode of the III-V ternary alloy semiconductor $In_{1-x}Ga_xP$ : S grown by the temperature gradient solution (TGS) was fabricated by Zn-diffusion, and it's characteristics was investigated. The carrier concentration of $In_{1-x}Ga_xP$ doped with sulfur, 0.5 mol %, was $1{\times}10^{17}cm^{-3}$ and the mobility was varied with the composition. In the case that the diffusion time was constant as 30 minutes. The temperature dependence of diffusion coefficient was decreased from D= $4.2{\times}10^{-5}$ exp (-1.74/$k_{B}T$) to D= $2.5{\times}10^{-5}$ exp (-3.272/$k_{B}T$) with increasing of composition $\times$ from 0.43 to 0.98. The major peak of E.L spectrum was due to D-A pair recombination and the peak intensity was increased with the increasing of input current. And the E.L intensity was decreased with the increasing temperature, and shift to the long wavelength. The luminescence efficiencies measured at $5^{\circ}C$, atmosphere temperature, was decreased from $2.6{\times}10^{-4}$% to $9.49{\times}10^{-6}$ % with increasing of composition it from 0.39, direct transition region, to 0.98, indirect transition region.

• Bulletin of the Korean Mathematical Society
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• v.34 no.4
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• pp.595-601
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• 1997

Let $C_d$ be the rational curve of degree d in $P_k ^3$ given parametrically by $x_0 = u^d, X_1 = u^{d - 1}t, X_2 = ut^{d - 1}, X_3 = t^d (d \geq 4)$. Then the defining ideal of $C_d$ can be minimally generated by d polynomials $F_1, F_2, \ldots, F_d$ such that $degF_1 = 2, degF_2 = \cdots = degF_d = d - 1$ and $C_d$ is a set-theoretically complete intersection on $F_2 = X_1^{d-1} - X_2X_0^{d-2}$ for every field k of characteristic p > 0. For the proofs we will use the notion of Grobner basis.