• Fibers and Polymers
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• v.5 no.3
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• pp.182-186
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• 2004

The effect of braid construction parameters on yarn cross-sectional shape is presented in this paper. The location of the yam within the braid unit cell is quantified by a compaction factor. A range of braided fabrics were produced and optically measured for actual yarn cross-sectional shape. A comparison of the theoretical and experimental values shows good correlation. Design curves can be produced with the developed model to allow selection of appropriate braid process parameter to create yarns with desired cross-sectional geometries.

• Fibers and Polymers
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• v.7 no.3
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• pp.305-309
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• 2006

This research studies the factors which influence the tensile strength of tire cords. Five yam samples are made by changing the spinning conditions and viscosity to get various physical properties. Different twisting methods are introduced and the yams are twisted under different processing conditions for each twisting process. With the experimental results, various analyses are performed to find the important factors in retaining strength after the twisting process. SEM and optical microscopic photographs are taken along with some measurements to assist the analysis.

• Korean Journal of Plant Resources
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• v.10 no.1
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• pp.50-57
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• 1997

Using a bioassay for tuber enlargement activity, which was carried out with culture of microtuber of nodal stem segments in vitro, the endogenous substances was detected from leaves of yam(Diosorea alata L., cv. Solo Yam) treated under the short and the long day length condition. Tuber enlargement activity was found in both the aqueous and ethyl acetate phase of extract obtained from leaves of yams. Those activity was found in both the aqueous and ethyl acetate phase of extract obtained from leaves of yams. Those activities increased under the short day length, whereas not increased under the long day length. Guided by bioassay, the active substances in the ethyl acetate phase were purified by charcoal adsorption chromatography. The result obtained indicated that the 40% ethanol fraction contained the most prominent tuber enlargement activity. In seasonal changes of the leaves, tuber enlargement activity remained almost constant during summer(June-August), but after. the middle of September, the activity increased gradually and then reached a maximum in early October. Jasmonic acid (JA) was isolated with the guidance of microtuber test and identified by gas chromatography. The level of endogenous JA in the leaves of plants was more than $290{\mu}g/kg$ at the 10 hr day length. These results seem evidences for the occurrence of the tuber enlargement activity which is formed in leaves under the short days and transmitted to under ground part to induce growth and enlargement of tuber.

• Journal of Life Science
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• v.21 no.8
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• pp.1142-1148
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• 2011

This study was conducted to investigate antioxidative and physiological activities of ethanol extracts concentration from Monascus-Fermented Chinese Yam (MFCY). The ethanol extracts from MFCY were measured to examine pigment, monacolin K content, total polyphenol content, DPPH radical scavenging activity and angiotensin converting enzyme inhibitory effects. In this study, the results show that Monascus sp. MK2, with Dioscorea batatas Dence. as the substrate, can produce pigments (red, orange, and yellow), monacolin K content, total polyphenol content and DPPH radical scavenging activity at 13.48 (red), 11.66 (orange), 12.77 (yellow), 462.78 (mg/kg), 658.8 (mg/kg) and 92.8% in EtOH extract, respectively. In addition, ACE inhibitory activity was shown to be 74.55% in EtOH extract. Therefore, it can be concluded that Dioscorea batatas Dence is the best fermentative substrate for Monascus species to produce secondary metabolites as biomedicinal substances.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.46-52
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• 2014

This study was carried out to investigate the characteristics of fermented chinese yam and rice (Dioscorea japonica, Dioscorea batatas, Dioscorea opposita, Rice, FCYR) using Monascus sp. MK805. The extracts from FCYR were measured to examine pigments, antioxidant activities were investigated through DPPH radical scavenging activity, total polyphenol and flavonoid contents, reducing power. Also it was investigated monacolin K productivity by FCYR. Pigments productivity (yellow, orange and red) were 26.2, 13.9, 17.3 at Dioscorea japonica, 41.9, 22.6, 53.2 at Dioscorea batatas, 12.5, 7.5, 9.7 at Dioscorea opposita and 10.1, 7.7, 10.2 at rice, respectively. DPPH radical scavenging activity of FCYR was about 69.7, 79.6, 57.8, and 42.3%, total polyphenol contents of FCYR was about 480.6, 658.7, 379.3, and 212.9 mg/kg, total flavonoid contents of FCYR was about 342.5, 448.4, 235.2, and 168.7 mg/kg, reducing power of FCYR was about 1.57, 2.14, 1.14, and 0.35 (OD at 700 nm), respectively. And then monacolin K productivity of FCYR was about 453.8, 509.5, 332.2, and 263.2 mg/kg, respectively.

• Textile Coloration and Finishing
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• v.18 no.1
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• pp.33-43
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• 2006

The purpose of this study was to eximine the effect of different yam twisting methods on mechanical properties and 3D CAD images of plain knitted fabrics made of composite yarns. Six yams were used in this study: four different composite yams of the six consist of acetate and functional polyester (Poly-m) with the ratio of 70:30, and the rest two are the original acetate $100\%$ yam and the poly-m $100\%$ yarn. The four kinds of composite yarns were processed in combinations of twisting processes such as interlacing, false twisting, two for one twisting, combined twisting and single covering, and the two original yams were knitted without any twisting process. Sixteen mechanical properties of all the six knitted fabrics, knitted under the same knitting conditions, were measured by KES-FB system with the outer knit condition. The results were as follows; 1) When the sample applied with the false twisting process at the temperature as high as $220^{\circ}C$, ENT, B, HB, G and RC values of samples increased which leads to increasing dimensional stability. 2) To gain the high bending and shear properties in the single covering process, selecting the core yarn with such properties is the most important factor. 3) Interlacing process effected to increase RC value. 4) False twisting process after interlacing process gave bulkiness and un-interlaced part in yam was increased SMD value. The SMD value of the kilted fabric of the composite yarn, which was put through the combined twist process, was higher than those of which simple process such as the two for one twist or the single covering process applied. In order to achieve the silk-like surface feel of knitted fabric, the sin91e covering process is recommended. 5) Examining the simulation images of the knifed fabrics of composite yarn, which were generated by the 3D CAD system based on the mechanical properties of the fabric, led that appearance could be changed as different twisting methods were applied.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.3
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• pp.425-430
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• 2011

This study evaluated the effect of extraction conditions of yam (Dioscorea aimadoimo) on antioxidant, moisturizing, collagenase activity, proliferation, and migration. Yam has been recognized as a healthy food due to its various biological activities, such as anti-obesity, anti-constipation, anti-mutagenic activities, as well as its ability to decrease blood glucose and cholesterol levels. Electron donating ability of high temperature ethanol extract of Dioscorea aimadoimo (HDA) had shown 70.6% at 400 mg/ml, and low temperature ethanol extract of Dioscorea aimadoimo (LDA) had shown 40% at 400 mg/ml. SOD-like activities of LDA and HDA were 23% and 34% at 400 mg/ml respectively. LDA significantly reduced the activity of collagenase in a dose-dependent manner, which was higher than HDA. The water contents in LDA-treated skin and HDA-treated skin were increased by 45.63% and 38.65% than the placebo cream respectively. The cellular proliferation of human dermal fibroblast neonatal (HDFn) was evaluated by MTT and cell migration assay. Compared to control, the cell proliferation was elevated to 109.7% and 114% by the treatment of LDA and HDA respectively at the concentration of 200 mg/ml. In addition, LDA and HDA were induced cell migration in HDFn. Our study suggests that LDA and HDA should be a very useful cosmetic ingredient, as anti-aging and skin moisturizer.

• Korean Journal of Medicinal Crop Science
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• v.8 no.2
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• pp.89-93
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• 2000

This experiment was conducted to investigate the effects of soil texture on agronomic characteristics and tuber yield in chinese yam (Dioscorea opposita Thunb). Tuber length and weight was greater and tuber shape was much better in sandy loam and loam soil than in sandy or clay loam soil. In loam and sandy loam soil, fresh tuber yield was increased by $21{\sim}27%$ in short-tuber type and 6% in long-tuber type, and large tubers yield (above 260g) was increased by $45{\sim}55%$ in short-tuber type and $20{\sim}22%$ in long-tuber type compared to those in sandy soil. There was no differences in large tuber yield at the 5% level of significance between loam and sandy loam soil. Malformation of tuber with bifurcation was extremely increased in sandy soil, and tuber diameter of long-tuber type was decreased in clay loam soil compared to those of the other soil texture.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.6 s.154
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• pp.870-879
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• 2006

In this study, the difference in the mechanical properties of silver and cotton weft knitted fabrics was studied. Six silver fabrics for the summer ladies' knit outwear were knitted varying knit structure and fabric density. Two commercial cotton knitted fabrics were selected to compare the properties. subjective sensation of hand of the fabrics was also studied. Mechanical properties of the fabric samples were measured by KES-FB system. From these, primary hand values(HV) were evaluated by the conversion equation (KW-403-KTU) and the total hand value(THV) was carried out according to the KW-304 Summer. The result of the research show that silver weft knitted fabrics had lower LT, RT, G, 2HG and higher EM, W, LC, WC, RC than cotton weft knitted fabrics. The use of silver yam contributed to increase in surface roughness of knitted fabrics. As the silver knitted fabrics became thicker compressional energy increased. The use of silver yarns contributed to much better fabric handle compared with the use of cotton yam only. It appeared that coefficient of friction of tuck stitch was larger than that of plain and interlock stitch. KOSHI and FUKURAMI values of the tuck samples were significantly higher than those values of the plain and interlock samples, while SHARI values were low in general. The total hand value of tuck stitch was higher than those of interlock and plain stitch.

• The Korean Journal of Rheology
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• v.8 no.3_4
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• pp.199-206
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• 1996

산마와 재배마에서 점질다당류를 추출하여 리올러지 및 열특성을 연구하였다. D.I.W 에서 산마와 재배마 점질다당류의 고유점도(η)는 각각 16.1 이/g. 25.1 이/g 이고 pH7일 때 최대값을 나타내었고 염을 가했을 때 (η)가 급격히 감소하다가 일정한 값을 나타내었으며 urea 용액에서 NaCl, MaCl2 용액에서보다 (η)가 높았다. 마 점질다당류의 chain stiffness는 0,0050이고 Overlap parameter는 산마와 재배마 점질다당류가 각각 0.06 g/이. 0.04 g/이였 다. 마 점질 다당류는 shear rate가 증가함에 따라 겉보기 점도가 감소하여꼬 농도가 증가함 에따라 yield stress 와 점조성 지수는 증가하고 shear index가 감소하는 가소성유동체였다. 산마 점질다당류는 35$^{\circ}C$까지 온도에 대하여 비교적 안정하였지만 그이상의 온도에서는 겉보 기 점도가 급격히 감소하였고 재배마 점질다당류는 온도가 증가할수록 겉보기 점도가 점차 적으로 감소하였다. 겉보기 점도는 1가 염가 2가 염 사이에 큰 차이가 없었고 염농도가 증 가함에 따라 겉보기 점도가 감소하였으나 urea를 첨가했을 때 겉보기 점도가 약간 감소하다 가 다시 증가하는 것을 알수 있었다. DSC로 산마와 재배마 점질다당류의 "true melting"을 측정했을 때 각각 92$^{\circ}C$, 93$^{\circ}C$였고, enthalpy는 67.06 cal/g, 75.83 cal/g였다. 겔화에 소요된 enthalpy는 pH가 증가할수록 큰 값을 나타냈고 NaCl을 첨가했을 때 감소하다가 염농도 증 가에는 영향을 받지 않았으며 Urea와 glycerol을 각각 첨가했을 때 D. I. W.오세보다 감소 하였다. TGA로 열분해 현상을 측정했을 때 분해 온도는 산마와 재배와 점질다당류가 각각 219~332$^{\circ}C$, 229~341$^{\circ}C$ 범위였다.TEX> 범위였다.