• Applied Microscopy
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• v.28 no.2
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• pp.193-205
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• 1998

The Urechis unicinctus sperm and spermatogenic cells prepared from the testis are investigated to identify $\alpha-tubulin$ of axoneme microtubules using mouse monoclonal $anti-\alpha-tubulin$ as the first Ab and Gold(10nm) conjugated goat anti-mouse IgG as the Ab marker. The Ag-Ab reaction analyzed excellently the localization of $\alpha-tubulin$ and the gold particles incorporated with the proximal and distal centrioles, manchette microtubules, and flagellum. The gold particles can be also observed in the spermatogenic cells while the cells are still in sperm ball which is composed of a somatic cell and spermatogenic cells. The sperm ball is the functional unit of sperm production in U unicinctus testis. The spermatids are developed from the spermatogenic cells in the sperm ball and released into the testis cavity through a cortical cytoplasmic opening. The spermatid architectures are similar with the mature sperm of the testis cavity in aspects of shape of discoid acrosome, degree of nuclear condensation and ring type of mitochondrion. However, the distal centriole connecting with the flagella can be observed from the mature sperm while the both proximal and distal centrioles reveal only in the spermatids. The proximal centriole is directly connected with nuclear outer membrane during the stage of nuclear condensation and oriented perpendicularly to the distal centriole whose axis coinciding with the longitudinal axis of the spermatozoon. There are indications that the distal centriole is intimately associated with the polymerization of the flagellum. The manchette microtubules appear during spermatid development but the mature sperm have round head and no conspicuous middle piece.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.311-316
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• 2017

The relationship between mean air temperature after heading and starch characteristics of colored rice grains was investigated using three colored rice cultivars. Pasting temperature within each rice cultivar with different harvest times differed. The pasting temperatures of two rice cultivars, Hongjinju and Joseongheugchal, reached the highest at 40 days after heading and decreased during the late harvest time. Distribution of amylopectin in the Hongjinju rice cultivar at the earlier harvest time contained a greater number of very short chains with the degree of polymerization (DP) between 6 and 12 and fewer chains with a DP from 13 to 24 than that of the later harvest time. However, there was little difference in the distribution of the longer chains of $25{\leq}DP{\geq}36$ and $37{\leq}DP$ for latter harvest times compared to that of the earlier ones. It was suggested that the structure of amylopectin affected the varietal differences in patterns of chain length of amylopectin during grain filling. In addition, the control of ripening was different from that causing the pigment effects in the fine structure of amylopectin in the three colored rice cultivars. Larger starch granules were observed in the Joseongheugchal rice cultivar and smaller granules occurred in the Hongjinju rice cultivar. The present study revealed that later harvest times led to a clear increase in the mean granule size of starch in the three colored rice cultivars.

• Polymer(Korea)
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• v.31 no.2
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• pp.141-147
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• 2007

Dental properties of polymer composite loaded with hybrid filler of barium silicate (BaSi) and hydroxyapatite, which is a principal component of human bone material, were investigated. A visible light system was utilized to activate the acrylic resin matrix of the composite. Based on the experimental results, it was found that mechanical strength of the composite was consistently increased with an increase of BaSi content in the hybrid filler. And those value rose above the dental specification enough to apply for dental materials. However, abrasion resistance was slightly decreased with increasing BaSi content in the filler. Depth of cure value was 6 to 9 mm applicable for dental restoration irrelevant to hybrid filler composition. On the other hand, there was no strict trend between filler composition and polymerization shrinkage as well as degree of conversion.

• Membrane Journal
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• v.16 no.4
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• pp.276-285
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• 2006

Acid-doped sulfonated poly(aryl ether benzimidazole) (S-PAEBI) copolymers were synthesized by a direct polymerization technique and a doping with phosphoric acid as a dopant, and the polymer electrolyte membranes were fabricated from them by a solution casting method. To optimize the reaction condition, the degree of sulfonation and doping level were varied in the ranges of $0{\sim}60%\;and\;0.7{\sim}5.7$, respectively. Physiochemical properties of the doped membranes were investigated by AFM, TGA and the measurement of proton conductivity. It was found that proton conductivities depend on doping levels of membranes. Conductivity determined at the condition of $130^{\circ}C$ and no humidity was $7.3{\times}10^{-2}S/cm$ for the $H_3PO_4$-doped PAEBI membrane with a doping level of 5.7.

• Composites Research
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• v.31 no.6
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• pp.299-303
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• 2018

In order to improve the interfacial bonding force and reaction polymerization degree of the carbon fiber reinforced nylon 6 composite material, the surface of the existing epoxy-sizing carbon fiber was desized to remove the epoxy and treated with urethane, nylon and phenoxy sizing agent, was observed. The interfacial bond strength of the resized carbon fiber was confirmed by IFSS (Interfacial Shear Strength) and the fracture surface was observed by scanning electron microscope. The results showed that the interfacial bonding strength of the carbon fiber treated with nylon and phenoxy sizing agents was higher than that of urethane - based sizing. It has been found that the urethane - type resizing carbon fiber has lower interfacial bonding strength than the conventional epoxy - sizing carbon fiber. This result shows that the interfacial bonding between carbon fiber and nylon 6 is improved by removing low activity and smoothness of existing carbon fiber.

• Food Engineering Progress
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• v.21 no.4
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• pp.383-390
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• 2017

Glucansucrase is an enzyme classified as a glycoside hydrolase (GH) 70 family, which catalyzes the synthesis of glucooligosaccharides with a low molecular weight using sucrose as a donor of D-glucopyranose and maltose as a carbohydrate acceptor. In this study, glucansucrase-producing lactic acid bacteria strain was isolated from the fermented foods collected in traditional markets, and the optimum conditions for the oligosaccharide production were investigated. The strain CCK940 isolated from Chinese cabbage kimchi was selected as an oligosaccharide-producing strain due to its high glucansucrase activity, with 918.2 mU/mL, and identified as Leuconostoc lactis. The optimum conditions for the production of oligosaccharides using Leu. lactis CCK940 were to adjust the initial pH to 6.0, add 5% (w/v) sucrose and 10% (w/v) maltose as a donor and acceptor molecules, respectively, and feed 5% (w/v) sucrose at 4 and 8 h of cultivation. When Leu. lactis CCK940 was cultured for 12 h at optimum conditions, at least four oligosaccharides with a polymerization degree of 2-4 were produced.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.1017-1027
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• 1995

This study was attempted to investigate physicochemical properties, molecular structural properties of native and acid-treated chestnut starch and chestnut starch gel. The amylose content was 18.9% and X-ray diffraction pattern showed Cb type. Swelling power was increased abruptly in the range of $65^{\circ}C{\sim}75^{\circ}C$ but increased slowly after that and solubility was increased abruptly until $70^{\circ}C$ but increased slowly after that. In amylograms which have different heating temperatures, cooling viscosity at $50^{\circ}C$ was reduced as heating temperature was increased. In molecular structural properties of amylose, ${\lambda}_{max}$ was 640 nm, ${\beta}-amylolysis$ limit was 84.2% and the degree of polymerization was 951 and in those of amylopectin, ${\lambda}_{max}$ was 570 nm, ${\beta}-amylolysis$ limit was 58.2%, the degree of polymerization was 1371 and average chain length was 22.6. In gel chromatography elution profiles of starch and amylose, 4.0% and 11.5% of low molecular weight-molecules($<5{\times}10^5$) were leached out. In gel chromatography elution profiles of soluble starch, the higher heating temperature was, the more high molecular weight-starches were leached out. The elution profiles after debranching amylopectin with pullulanase showed 2.2 of the ratio of peakIII(DP 10-15) to peakII(DP 35-45). Acid hydrolysis extent of 2.2 N HCI-treated starch at $35^{\circ}C$ for 10 days was 96% and hydrolysis rate showed two step pattern which had border line at 4 days. In elution profiles of acid treated chestnut starch, amylopectin peak was disappeared compeletly after 6 hrs and converted short chains of DP 10-15. Amylose content was increased until 6 hrs but decreased after that. Hardness of starch gel made at $75^{\circ}C$ of heating temperature and cohesiveness of starch gel made at $85^{\circ}C$ of heating temperature were the highest. Retrogradation rate of starch gels were relatively high, especially for the starch gel made at $75^{\circ}C$ of heating temperature.

• Journal of Sericultural and Entomological Science
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• v.45 no.1
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• pp.34-45
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• 2003

Silk was treated with calcium hydroxide for degumming at different treatment times, temperatures and Ca(OH)$_2$ concentration to optimize degumming conditions in this thesis. After degumming, soluble and insoluble sericin were seperated and then the soluble sericin was characterized by measuring the average degree of polymerization (D.P.), lysinoalanine (LAL) content, DSC, and by amino acid analysis. And degummed silk fibroin was characterized by measuring tenacity and SEM. Degumming loss was increased by increasing the treatment time and temperature until about 30 minutes. After then, a slight difference was found along with treatment times at the Ca(OH)$_2$ concentrations of 0.07% and 0.1% solutions. After degumming, insoluble sericin ratio on degumming solution was increased by increasing treatment temperature at Ca(OH)$_2$ 0.04% solution. At the concentration Ca(OH)$_2$ of 0.07%, a soluble ratio was almost 100% regardless of treatment time and temperature. At the beginning of treatment, insoluble ratio was high at Ca(OH)$_2$ 0.1% solution but it was decreased by increasing treatment time. At the Ca(OH)$_2$ concentration of 0.04%, D.P. of soluble sericin was maintained as a constant value of 10 at 100$^{\circ}C$ although treatment time was increased. However, at 80$^{\circ}C$ and 90$^{\circ}C$, it was hard to prepare a soluble sericin having a constant D.P. by increasing treatment time. At the Ca(OH)$_2$ concentration of 0.07%, D.P. was almost 10 irrespective of treatment temperature and time. Soluble sericins with high D.P. of 20∼30 were obtained at 0.1% and 100$^{\circ}C$. LAL was not detected in soluble sericin. As the results of amino acid analysis, it showed that Ca(OH)$_2$ degumming reduced the contents of hydroxy amino acids like Ser., Thr. and Tyr. In DSC analysis of soluble sericin, endothermic peak by thermal deformation and pyrolysis showed at 189$^{\circ}C$ and at 299$^{\circ}C$, respectively. The tenacities of degummed silk were 15∼30% lower than that of raw silk. And it was decreased with increasing treatment time. From the morphological study, the thickness of degummed silk fibroin became thinner by increasing degumming loss. The roughness of a silk fibroin surface was appeared as treatment concentration was increased.

• Korean Journal of Food Science and Technology
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• v.54 no.4
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• pp.377-385
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• 2022

This study examined the dietary fiber content of potato and physicochemical characteristics of potato starch isolated from various cultivars. The total dietary fiber content of the Arirang1ho cultivar was 6.30%, which was higher than that of other cultivars. The amylose content ranged from 36.76-55.75%, with Sooseon having the highest amylose content. Analysis of the degree of amylopectin polymerization revealed that all cultivars had a high proportion of DP (degree of polymerization) 13-24. The phosphate content ranged from 45.90-84.23 mg/100 g, with Arirang1ho having the highest and Eunseon having the lowest phosphate content. The resistant starch content ranged from 58.94-79.87%. Geumseon showed the highest breakdown in the range of 587.45-1,129.72 RVU (rapid viscosity unit). Sooseon had the lowest gelatinization enthalpy value for potato starch in the range of 5.54-7.64 J/g. These results provide basic data for the use of potatoes in industrial applications.

• Journal of Sericultural and Entomological Science
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• v.28 no.2
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• pp.65-73
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• 1986

These studies are carried out to improve silk availability for anticrease by useing methacrylate monomer polymerization method with in silk fiber. For this purpose, degree of anticrease, stiffness and shrinkage of various silk fabrics, included finish or not, after repeat of washings and polyster fabric was compared as standard. The adopted samples are ; 1. Polyester, Georgette, Woven density…90cm-85g/m 2. Silk, Twill, Degumed, Light, Woven density…90cm-90g/m 3. Silk, Twill, Degumed, Heavy, Woven density…90cm-200g/m 4. Silk, Stain, Degumed, Light, Woven density…90cm-90g/m The reached results are as followings. 1. The results of improving on anticrease by the finished method were about ten per cent increase against their original samples. 2. The light density silks showed satisfactory improve for anticrease, but the heavy one remained as rather poor condition. 3. The results for degree of textile stiffness were investigated to make sure reserve their textile feeling and observed to be good condition upon the finish work. 4. Textile shrinkage after the repeat of soap wash was investigated on indivisual test sample and silk fabrics showed more shrinkage than polyester which it seemed to be tentering shrinkage druning their general finishing processes. 5. The investigation showed that anticrease, stiffness and shrinkage of the sample textile were more or less deteriorated regardless silk or polyester by the repeat of washings. These matters are considered that such results were obtained because of the fiber fatigue nature. 6. The report reached that silk textiles should be used by dry cleaning methed after finish of any resin finish to reserve their improved anticrease nature.