• Asian-Australasian Journal of Animal Sciences
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• v.21 no.12
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• pp.1773-1778
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• 2008

Two experiments were carried out to study the effects of corticosterone (CORT) administration on intestinal morphology and function of broilers. In both experiments, birds were randomly divided into two equal groups. One group was the control group (CTRL), and the birds were fed with a basal diet. The other was the experimental group (CORT), and the birds were fed with the basal diet plus 30 mg of CORT/kg diet. At 21 days of age, performance, morphological characteristics of intestine, D-xylose level in plasma, activities of digestive enzymes in digesta, digestibility of nutrients and 5-bromo-2-deoxyuridine (BrdUrd)-labeling index of intestinal epithelial cells were determined. CORT administration decreased feed intake, daily gain and feed conversion ratio (p<0.05). CORT also decreased duodenal and jejunal villus height (p<0.05) as well as crypt depth (p<0.05). The D-xylose level in plasma of CORT-treated broilers was lower than that of the control (p<0.05). CORT treatment caused a decrease in apparent digestibility of protein (p<0.05), whereas fat and starch apparent digestibilities were unaffected (p>0.05). CORT administration increased activities of trypsin and amylase (p<0.05), and decreased BrdUrd-labeling index of duodenal and jejunal epithelial cells (p<0.05). In conclusion, CORT administration impaired the normal morphology and absorptive capacity of the small intestine of broiler chickens.

• Journal of the Korean Applied Science and Technology
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• v.21 no.2
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• pp.132-139
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• 2004

Film forming behavior of monodispersed model composite latexes with particle size of 190 nm, which consist of n-butyl acrylate as a soft phase monomer and methyl methacrylate as a hard phase monomer with different morphology was examined. Five different types of model latexes were used in this study such as random copolymer particle, soft-core/hard-shell particle, hard-core/soft-shell particle, gradient type particle, and mixed type particle. The film forming behavior was evaluated using pseudo on-line measurements of the cumulative weight loss, the UV transmittance, and the tensile fracture energy. Each stages of film formation I, II were not sensitive to the morphology of model latexes, but stage-ill was largely dependent on the morphology of model latexes. The chain mobility of polymer which composed the shell component was found to dominantly determine the behavior of film forming stage-III.

• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.737-745
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• 2017

This study was carried out to investigate the changes in micro- and nanoscopic morphology of cellulose nanofibrils (CNFs) from various bioresources by investigating various mechanical milling systems. Mechanical milling in herbaceous bioresources was more effective than in woody bioresources, demonstrating lower energy consumption and finer morphology. The milling time to reach nanoscopic size was longer in woody bioresources than in herbaceous bioresources. Furthermore, at the same level of wet disk milling time, CNFs from herbaceous bioresources showed more slender morphology than those from woody bioresources. Tensile properties of nanopaper prepared from CNFs of herbaceous bioresources were higher than those of woody bioresources. The highest tensile strength was found to be 77.4 MPa in the nanopaper from Evening prim rose.

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.1-6
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• 1998

Morphology and reproduction of the two similar Acrosorium species, A. polyneurum and A. yendoi, were studied based on specimens collected from Korea. The morphology of the former species was very variable, depending on its habitat, and in some cases shown superficial resemblance to that of A. yendoi. Also its reproductive structures were essentially the same as those of the latter. However, the two species appear to be distinguished by some vegetative features found in fully developed stage, such as thallus size, vein structures and branching pattern. Acrosorium polyneurum has comparatively large thallus (6-8cm) with three to five cell-layered macroscopic veins, together with palmately dichotomously branching, whereas A. yendoi is of smaller thallus (3-6cm) with microscopic veins of one to three cell layers, and shows irregularly dichotomously or pinnately branching. This result, together with recent data based on PCR technique, suggests that the two entities are distinct.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2223-2227
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• 2010

Reaction of [(bpy)Pd]$(PF_6)_2$ (bpy = 2,2'-bipyridine) with racemic bis(isonicotinoyl)-1,1'-bi-2-naphtholate (L) in acetone, and followed by addition of chloroform and solvent evaporation allows to form amorphous micro-bowl morphology consisting of $[(bpy)PdL]_2(PF_6)_4$ without any template or additive. In contrast, the reaction and recrystallization in acetone for 1 week produce parallel-piped single crystals consisting of $[(bpy)_3Pd_3({\mu}_3-HPO_4)_2](PF_6)_2$. The formations of micro-bowl and parallel-piped single crystal morphologies appear to be primarily associated with the kinetic and thermodynamic control, respectively. The formation of micro-bowls may be attributed to eruption of organic solvents. Cosolvent effects and chemical properties on the formation of micro-bowl morphology have been observed.

• Journal of the Korean Ceramic Society
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• v.40 no.6
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• pp.601-607
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• 2003

Osteoblast-like cell morphology, proliferation, and differentiation were examined in variation with biomaterials. Cells were cultured on TiO$_2$, Ti, 3Y-TZP, HA (Hydroxyapatite) and Thermanox was used as a control specimen. Generally, all specimens have similar cell morphology within the same time interval. However, cells on HA seem to be more thicker than those on TiO$_2$, Ti, 3Y-TZP and cell overlapping was detected very frequently on HA. In case of cell proliferation and differentiation, bioactive material such as HA could help osteoblast-like cell proliferate and provoke a sharp increase of ALP. On the other hand, whether the substrate material is a bioinert ceramics or metal, it does not so strongly affect the cell attachment, proliferation. and differentiation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.5
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• pp.835-841
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• 1997

Microscopic examination of the morphology of wear debris is an accepted method for machine condition and fault diagnosis. However wear particle analysis has not been widely accepted in industry because it is dependent on expert interpretation of particle morphology and subjective assessment criteria. This paper was undertaken to analyze the morphology of wear debris for machine condition diagnosis of the lubricated moving surfaces by image processing and analysis. The lubricating wear test was performed under different sliding conditions using a wear test device made in our laboratory and wear testing specimen of the pin-on-disk-type was rubbed in paraffine series base oil. In order to describe characteristics of debris of various shape and size, four shape parameters (50% volumetric diameter, aspect, roundness and reflectivity) have been developed and outlined in the paper. A system using such techniques promises to obviate the need for subjective, human interpretation of particle morphology in machine condition monitoring, thus to overcome many of the difficulties in current methods and to facilitate wider use of wear particle analysis in machine condition monitoring.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.219-222
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• 2004

Removal characteristics of Mn and Co was studied from the contaminated solutions via surface reaction with various calcium carbonate (calcite). Synthetic calcium carbonates which has different surface morphology as well as surface areas were prepared by a spontaneous precipitation method and used. Mn and Co removal behavior by the different solid surface demonstrate characteristic sorption behaviors depend on the type of calcite used, such as surface area or surface morphology. Calcium carbonate crystals (mostly calcite) which exhibit complicated surface morphology (c-type) shows strong sorption affinity for Mn and Co removal via sorption than on the a-type or b-type calcite crystals of less complicated surfaces. The applicability of two kinetic models, the pseudo-first-order kinetic equation and the Elovich kinetic model was examined on these sorption behavior. Elovich kinetic model was found more suitable to explain the very early stage adsorption kinetics, while the pseudo-first-order kinetic equation was successfully fitted for the adsorption kinetics after 50 hours.

• Composites Research
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• v.27 no.3
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• pp.115-121
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• 2014

The effect of addition of gypsum on the rheology, physico-mechanical properties, thermal properties and morphology development of polymer composites based on polyvinyl chloride (PVC) and waste-gypsum with and without methylene-butadiene-styrene (MBS) has been studied. It was shown that the replacement of gypsum for methylene-butadiene-styrene (MBS) component in PVC/gypsum polymer composites enhanced the tensile strength and stiffness of composites, but gradually decreased its impact strength. The observation of morphology, the results of the physico-mechanical properties and thermal properties proved simultaneously that PVC/gypsum composite with the waste-gypsum content of 22.56 wt% reached the optimum results among five kinds of PVC/gypsum polymer composite materials investigated.

• ALGAE
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• v.21 no.4
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• pp.417-423
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• 2006

Morphology and molecular phylogeny of a red algal species, Hypnea flexicaulis that is recently described from Japan, were investigated based on 23 collections from Korea (21), Taiwan (1), and the Philippines (1). Hypnea flexicaulis has percurrent axes with flexuous, antler-like branches which have wide branching angles, and abaxially curved ultimate branchlets. In order to study DNA divergence and phylogenetic relationships of the species, we determined plastid rbcL and mitochondrial cox1 sequences from the 23 collections. All 21 specimens from five different locations in Korea were almost identical to H. flexicaulis from Japan in rbcL sequences. Although there was a difference of three to five base pairs (bp) between samples from Korea and the Philippines or between the Philippines and Taiwan, Bayesian analyses of the rbcL data showed that all specimens from Korea, Japan, the Philippines, and Taiwan were strongly monophyletic. However, it is interesting that specimens from the Philippines differed by 31-34 base pairs in mitochondrial cox1 gene from those of materials from Korea and Taiwan, which differed by one to seven bp in rbcL between them. Although H. boergesenii is different from H. flexicaulis in having many antler-like branchlets, both appeared as sisters in all analyses of the rbcL data. This is the first report of H. flexicaulis from Korea based on morphology, rbcL, and cox1 gene sequences.