Single hook model of fiber figures in card webs

In card webs, many fibers are not straight and generally have hooks or bends. In this study, a one-dimensional fiber figure model is discussed. Using correlation coefficients, a simple classification method for fiber figures is proposed. This method enables us to classify fiber figures into five categories: straight, leading- and trailing-hooked, and leading- and trailing-bent figures. This method is then applied to experimental data. The results indicate that the absolute values of the correlation coefficients of the vector quantities between the measured fiber figures and one of our models are greater than 0.8 in many cases. Thus, our proposed method is viable for the classification of fiber figures in card webs.ArticleTEXTILE RESEARCH JOURNAL. 86(11):1121-1127 (2016)journal articl

Friedrich Ranke: Gott, Welt und Humanität in der deutschen Dichtung des Mittelalters (Übersetzung I)

原著 : フリードリヒ・ランケ,　翻訳 : 木村昭

Application of a truncated distribution for tsumugi yarn width

Hand-spun, silk yarn made from floss silk is referred to as tsumugi yarn. It gives a unique appearance on the products, also called tsumugi, which are considered to be an important type of fabric for their aesthetics. The essential factor of this visual effect is originated by the thickness variation of tsumugi yarn; however, the detail of the variation is unknown. In this paper, as a fundamental study of tsumugi yarn, its width distribution is discussed. To model the width distribution, the Polya-Eggenberger distribution is introduced. Moreover some modifications are applied for the distribution to describe the yarn's situation. That is to say, it is impossible to be thinner than a level of thickness for the yarn to maintain a shape of a thread; on the other hand, tsumugi yarn is not limited to only containing thicker parts. Additionally, it is unavoidable to involve errors and fluctuations in the actual data. Hence, the distribution is truncated and convoluted. By using an image scanner, the width of tsumugi yarn is measured. With the measured data, the parameters of the width distribution are estimated using the maximum likelihood method. The results show that the width distribution of tsumugi yarn is asymmetric and well summarized by the distribution.ArticleTEXTILE RESEARCH JOURNAL. 85(9):929-935 (2015)journal articl

Dehydration of main-chain amides in the final folding step of single-chain monellin revealed by time-resolved infrared spectroscopy

Kinetic IR spectroscopy was used to reveal β-sheet formation and water expulsion in the folding of single-chain monellin (SMN) composed of a five-stranded β-sheet and an α-helix. The time-resolved IR spectra between 100 μs and 10 s were analyzed based on two consecutive intermediates, I1 and I2, appearing within 100 μs and with a time constant of ≈100 ms, respectively. The initial unfolded state showed broad amide I′ corresponded to a fluctuating conformation. In contrast, I1 possessed a feature at 1,636 cm−1 for solvated helix and weak features assignable to turns, demonstrating the rapid formation of helix and turns. I2 possessed a line for solvated helix at 1,637 cm−1 and major and minor lines for β-sheet at 1,625 and 1,680 cm−1, respectively. The splitting of the major and minor lines is smaller than that of the native state, implying an incomplete formation of the β-sheet. Furthermore, both major and minor lines demonstrated a low-frequency shift compared to those of the native state, which was interpreted to be caused by hydration of the C=O group in the β-sheet. Together with the identification of solvated helix, the core domain of I2 was interpreted as being hydrated. Finally, slow conversion of the water-penetrated core of I2 to the dehydrated core of the native state was observed. We propose that both the expulsion of water, hydrogen-bonded to main-chain amides, and the completion of the secondary structure formation contribute to the energetic barrier of the rate-limiting step in SMN folding