• Structural Engineering and Mechanics
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• v.90 no.3
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• pp.219-232
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• 2024

In current study, for the first time, Nonlinear Bending of a skew microplate made of a laminated composite strengthened with graphene nanosheets is investigated. A mixture of mechanical and thermal stresses is applied to the plate, and the reaction is analyzed using the First Shear Deformation Theory (FSDT). Since different percentages of graphene sheets are included in the multilayer structure of the composite, the characteristics of the composite are functionally graded throughout its thickness. Halpin-Tsai models are used to characterize mechanical qualities, whereas Schapery models are used to characterize thermal properties. The microplate's non-linear strain is first calculated by calculating the plate shear deformation and using the Green-Lagrange tensor and von Karman assumptions. Then the elements of the Couple and Cauchy stress tensors using the Modified Coupled Stress Theory (MCST) are derived. Next, using the Hamilton Principle, the microplate's governing equations and associated boundary conditions are calculated. The nonlinear differential equations are linearized by utilizing auxiliary variables in the nonlinear solution by applying the Frechet approach. The linearized equations are rectified via an iterative loop to precisely solve the problem. For this, the Differential Quadrature Method (DQM) is utilized, and the outcomes are shown for the basic support boundary condition. To ascertain the maximum values of microplate deflection for a range of circumstances-such as skew angles, volume fractions, configurations, temperatures, and length scales-a parametric analysis is carried out. To shed light on how the microplate behaves in these various circumstances, the resulting results are analyzed.

• Journal of Agricultural Extension & Community Development
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• v.30 no.4
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• pp.229-241
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• 2023

This study aims to examine the farm household income and consumption structure change as well as farm income inequality. Data from the Agricultural Household Survey for the years 2016, 2021, and 2022 were hired to analyze farm income inequality by the Gini coefficient decomposition method. Results show that from 2016 to 2021, all income quintiles exhibited an increasing trend, but in 2022, income decreased across all quintiles. As a result of analyzing farm household consumption expenditure, consumption expenditure increased in all income quintiles in 2021 and 2022 compared to 2016, but consumption of optional goods decreased in the fifth quintile. In addition, it was found that farmers in the first quartile had higher consumption expenditures and expenditures on options than those in the second quartile. The analysis of farm income by region show that public subsidies increased significantly for general rural farmers than for farmers in special and metropolitan areas in all income quintiles during the period. In the case of the first quintile, farm household income in rural areas in special and metropolitan cities increased compared to general rural areas. In the fifth quartile, agricultural income and sideline income in general rural areas increased compared to rural areas in special and metropolitan cities, while rural areas in special and metropolitan cities increased non-business income compared to rural areas. Results of farming income inequality by income type show a steady decline in inequality from 2016 to 2022, indicating that the decreasing gini coefficinet of public subsidies is contributing to the decline in farm income inequality. Private subsidies and side income are shown to increase inequality.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.311-319
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• 2023

Caveolin-1 (Cav-1) is the main structural component of the caveolae on the plasma membrane, which regulates various cellular processes, including cell growth, differentiation, and endocytosis. Although a recent study demonstrated that Cav-1 might be involved in diabetes-associated inflammation, its exact role in the intestine was unclear. In this study, we examined the intestinal expression of Cav-1 in diabetic conditions. We also investigated its effect on lipopolysaccharide (LPS)-induced inflammation by expressing this protein in human intestinal Caco-2 cells lacking Cav-1. We observed that increased Cav-1 levels and decreased expression of tight junction proteins affected intestinal permeability in high-fat diet-induced diabetic mice. When Caco-2 cells were treated with LPS, Cav-1 enhanced the NF-κB signaling. Moreover, LPS reduced the expression of tight junction proteins while it increased cell-cell permeability and reactive oxygen species generation in Caco-2 cells and this effect was amplified by cav-1 overexpression. LPS treatment promoted phosphorylation of tyrosine-14 (Y14) on Cav-1, and the LPS-induced NF-κB signaling was suppressed in cells expressing non-phosphorylatable Cav-1 (tyrosine-14 to phenylalanine mutant), which reduced intestinal barrier permeability. These results suggest that Cav-1 expression promotes LPS-induced inflammation in Caco-2 cells, and phosphorylation of Y14 on Cav-1 might contribute to the anti-inflammatory response in LPS-induced NF-κB signaling and cell permeability.

• Structural Engineering and Mechanics
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• v.91 no.1
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• pp.1-23
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• 2024

This paper formulates a new integral shear deformation shell theory to investigate the free vibration response of carbon nanotube (CNT) reinforced structures with only four independent variables, unlike existing shell theories, which invariably and implicitly induce a host of unknowns. This approach guarantees traction-free boundary conditions without shear correction factors, using a non-polynomial hyperbolic warping function for transverse shear deformation and stress. By introducing undetermined integral terms, it will be possible to derive the motion equations with a low order of differentiation, which can facilitate a closed-form solution in conjunction with Navier's procedure. The mechanical properties of the CNT reinforcements are modeled to vary smoothly and gradually through the thickness coordinate, exhibiting different distribution patterns. A comparison study is performed to prove the efficacy of the formulated shell theory via obtained results from existing literature. Further numerical investigations are current and comprehensive in detailing the effects of CNT distribution patterns, volume fractions, and geometrical configurations on the fundamental frequencies of CNT-reinforced nanocomposite shells present here. The current shell theory is assumed to serve as a potent conceptual framework for designing reinforced structures and assessing their mechanical behavior.

• Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.346-355
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• 2024

Groupers are economically important species in the fishery and aquaculture industries in Asian countries. Various species of grouper, including hybrids, have been brought to market even without precise species identification. In this study, we analyzed the structure and expression profile of the gene encoding prolactin (PRL) in the red-spotted grouper Epinephelus akaara based on genomic DNA and cDNA templates. The results showed that the PRL gene consists of five exons encoding an open reading frame of 212 amino acids, including a putative signal peptide of 24 amino acids and a mature structural protein of 188 amino acids. It showed amino acid identities of 99% with Epinephelus coioides, 83% with Amphiprion melanopus, 82% with Acanthopagrus schlegelii, 75% with Oreochromis niloticus, 70% with Coregonus autumnalis, and 67% with Oncorhynchus mykiss, indicating its closer similarity to E. coioides and other groupers but marked distinction from non-teleost PRLs. PRL mRNA expression was detected mostly in the brain, including the pituitary gland, with little expression in other tissues. While the 5-exon structure of the PRL gene of red-spotted grouper and the exon sizes were conserved, the sizes of the introns, particularly the first intron, were markedly different among the grouper species. To examine whether these differences can be used to distinguish groupers of similar phenotypes, exon-primed intron-crossing analysis was carried out for various commercially important grouper species. The results showed clear differences in size of the amplified fragment encompassing the first intron of the PRL gene, indicating that this method could be used to develop species-specific markers capable of discriminating between grouper species and their hybrids at the molecular level.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.4
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• pp.48-58
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• 2009

Glycosyl hydrolases (GH, EC 3.2.1.-) are key enzymes which can hydrolyze the glycosidic bonds between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. The new enzyme nomenclature of glycoside hydrolases is based on their amino acid sequence similarity and structural features. Here, we examined the glycosyl hydrolase family(GHF) genes reported from earthworm species. Among overall 115 GHFs, 12 GHFs could be identified from earthworm species through CAZy database. Of 12 GHF group genes, five genes including GHF2, 5, 17, 18, 20 are thought to be potent for industrial applications. The alignment of these genes with same genes from other animal species exhibited high sequence homology and some important amino acid residues necessary for enzyme activity appeared to be conserved. These genes can be utilized as a pest control agent or applicable to the food industry, clinical therapeutics and organic wastes disposition.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.3
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• pp.21-32
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• 2009

As an alternative for restoring a sense of community which has been broken up due to urban residence redevelopment, this study focuses on structural characteristics according to physical location of central squares in apartment complexes. Central squares do not simply function as inner-aiming and self-completed spaces for the residents, but their role can be expanded to a core location which encourages neighbors to communicate and interact with each other. The suppositions for this study are as follows. Structural characteristics according to the physical locations of the central squares in apartment complexes affect apartment residents' openness toward their neighbors and non-residents' accessibility to the square. At the same time, it influences the sense of community. In addition, psychological distance which is represented as psychological openness and accessibility forms a reciprocal relationship with the sense of community. For the study, we first categorized central squares as either open-structure or closed-structure based on how accessible it is from outside the apartment complex. According to these types of central squares, Sillim Prugio, Banghak Deasang Town Hyundai, Gwanak Prugio and Banghak Samsung Raemian 1 which have similar conditions and different structures were selected as sites of the study. Then each apartment complex was classified by apartment residents and non-residents so that eight groups were prepared for the survey. The results of the questionnaire survey especially regarding measuring the sense of community, psychological openness and accessibility indicated that the suppositions were right. Hence, the sense of community, psychological openness and accessibility are high in a central square with an open-structure while high standards of psychological openness and accessibility guarantee a positive sense of community. This study is meaningful in that it verifies that the physical location of central squares is reciprocally related to psychological openness, accessibility and a sense of community. At the same time, this study may serve as theoretical grounds for the planning and construction of practical central squares.

• Journal of the Mineralogical Society of Korea
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• v.29 no.3
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• pp.155-165
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• 2016

Understanding the effect of boron content on atomic structures of boron-bearing multicomponent silicate melts is essential to reveal the atomistic origins of diverse geochemical processes involving silica-rich magmas, such as explosive volcanic eruption. The detailed atomic environments around B and Al in boron-bearing complex aluminosilicate glasses yield atomistic insights into reactivity of nuclear waste glasses in contact with aqueous solutions. We report experimental results on the effect of boron content on the atomic structures of sodium borate glasses and boron-bearing multicomponent silicate melts [malinkoite ($NaBSiO_4$)-nepheline ($NaAlSiO_4$) pseudo-binary glasses] using the high-resolution solid-state NMR ($^{11}B$ and $^{27}Al$). The $^{11}B$ MAS NMR spectra of sodium borate glasses show that three-coodrinated boron ($^{[3]}B$) increases with increasing $B_2O_3$ content. While the spectra imply that the fraction of non-ring species decreases with decreasing boron content, peak position of the species is expected to vary with Na content. Therefore, the quantitative estimation of the fractions of the ring/non-ring species remains to be explored. The $^{11}B$ MAS NMR spectra of the glasses in the malinkoite-nepheline join show that four-coordinated boron ($^{[4]}B$) increases as $X_{Ma}$ [$=NaBSiO_4/(NaBSiO_4+NaAlSiO_4)$] increases while $^{[3]}B$ decreases. $^{27}Al$ MAS NMR spectra of the multicomponent glasses confirm that four-coordinated aluminum ($^{[4]}Al$) is dominant. It is also observed that a drastic decrease in the peak widths (full-width at half-maximum, FWHM) of $^{[4]}Al$ with an addition of boron ($X_{Ma}=0.25$) in nepheline glasses. This indicates a decrease in structural and topological disorder around $^{[4]}Al$ in the glasses with increasing boron content. The quantitative atomic environments around boron of both binary and multicomponent glasses were estimated from the simulation results of $^{11}B$ MAS NMR spectra, revealing complex-nonlinear variation of boron topology with varying composition. The current results can be potentially used to account for the structural origins of the change in macroscopic properties of boron-bearing oxide melts with varying boron content.

• Korean journal of food and cookery science
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• v.26 no.6
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• pp.872-886
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• 2010

Six kinds of sunsik containing different contents of brown rice(BR; 20, 30, and 50%) were prepared and subjected to various processing conditions(with or without roasting at $200^{\circ}C$ for 20 min e.g., designated as RBR50 or BR50) to assess their functionality as ready-to-eat foods. They were also assessed for their nutritional and sensory properties and oxidative stability. Dietary fiber contents were proportionate to the levels of added BR. Protein was highest in RBR50 (p<0.001), which also had the highest amounts of free and structural amino acids. The amount of free amino acids tended to increase with roasting, although most amino acids were present in structural form. Oleic acid and linoleic acid were the predominant fatty acids in all prepared sunsik, and RBR50 presented noticeably higher peroxidability index due to its higher amount of linoleic acid(p<0.05). Nevertheless, RBR50 showed good oxidative stability; this phenomenon was observed in all sunsik with roasted BR but not in those with non-roasted BR. It is implied that potential antioxidants might have been newly formed or converted from their precursors while BR was roasted. Roasting process also had an impact on the sensory properties of sunsik, e.g., sunsik with added roasted BR showed lower dissolution and darker color intensity compared to its counterpart sunsik.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.2
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• pp.115-122
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• 2002

In this study, the effects of alfalfa hay included in different ratios of 60%(A), 50%(B), 40%(C) and 30%(D) for the diets of young weaned Korean native goats were investigated on feed intake, digestibilities of nutrients, nitrogen retention, average daily gain and feed efficiency. Crude protein contents of experimental diets were 18% in all treatments. The contents of ADF, NDF and crude ash were higher in A as 26.1, 37.0 and 9.0% compared to the lowest values in D of 20.3, 30.4 and 6.6%. However the contents of non-structural carbohydrates was in the opposite tendency. Daily feed intake (DM) was highest in A (414.4g) and B (417.7g) and significantly (p<0.05) lower in D(362.6g). Dry matter intake per metabolic basal weight (DM g/kg of $BW^{0.75}$ ) were highest in A(73.9g) and lowest in D(64.0g). Average daily gain and feed efficiencies were in the range of 33.3~48.7g and 8.1~13.4% respectively with no statistical differences, however with the increasing trends according to higher percent of roughage in the diets. Digestibilities of dry matter (DM), organic matter (OM), crude protein (CP), ADF, NBF, crude ash (CA) and non-structural carbohydrates (NSC) were in the tendency of becoming higher according to higher ratios of concentrate but becoming lower according to higher ratio of alfalfa hay in the diets fed to Korean native goats. Nitrogen retention was lowest in A (1.8g, 15.5%) and highest in D (2.7g, 25.7%). In overall, inclusion of 30~40% alfalfa hay as a roughage in the diets of weaned Korean native goats was superior to the higher rates of inclusion of alfalfa hay in aspects of average daily gain and feed efficiency. The fixed 18% of crude protein content in the diets was efficient for the growth of weaned goats.