Analysis of acoustic characteristics of fabrics in terms of mechanical properties

The purpose of this study was to classify various fabrics into some meaningful groups and to predict the fabrics’ acoustic characteristics using their mechanical properties. Two hundred seventeen fabrics, fifty one knitted fabrics, fifty nine woven fabrics and one hundred and seven vapor permeable water repellent fabrics, were used as test specimen. Fabric frictional sounds of the specimen were measured with a MAFN(Measuring Apparatus for Fabric Noise, Patent: No, 2001-73360). Sound Pressure Level(SPL), psychoacoustic parameters such as Loudness(z) and Sharpness(z) of the specimen were obtained by the sound quality system. KES-FB system was used for mechanical property measurements. Cluster analysis was used to classify the specimen and discriminant analysis was used to predict the clusters. Linear regression analysis was used to suggest the equations to predict the acoustic properties using mechanical properties.     

Sound absorption of multiple layers of nanofiber webs and the comparison of measuring methods for sound absorption coefficients

Textile sound absorbents are getting more and more popular on the market as noise reduction is a major requirement for human comfort today. In this paper we focus on a new textile material for sound absorption, by investigating the acoustic characteristics of nanofibers. Through impedance tube method we measured the sound absorption coefficients of multiple layers of nanofiber webs and compared those with microfiber materials per fabric weight. We also examined the effect of layers of nanofiber webs on regularfiber knitted fabric on sound absorption. The test results showed that the sound absorption coefficients of nanofiber layers were superior that of microfiber fabrics in the frequency range 1000–4000 Hz. In this range, the sound absorption of nanofiber webs improved with numbers of layers. Also, adding nanofiber web plies to regularfiber fleece increased the sound absorption coefficient with 85 % at 4000 Hz. From our results we could observe differences in the sound absorption coefficients between two test methods, which are higher absorbance coefficients through the reverberation room method than impedance tube method.     

An Ethanol Extract Derived from Bonnemaisonia hamifera Scavenges Ultraviolet B (UVB) Radiation-Induced Reactive Oxygen Species and Attenuates UVB-Induced Cell Damage in Human Keratinocytes

The present study investigated the photoprotective properties of an ethanol extract derived from the red alga Bonnemaisonia hamifera against ultraviolet B (UVB)-induced cell damage in human HaCaT keratinocytes. The Bonnemaisonia hamifera ethanol extract (BHE) scavenged the superoxide anion generated by the xanthine/xanthine oxidase system and the hydroxyl radical generated by the Fenton reaction (FeSO₄ + H₂O₂), both of which were detected by using electron spin resonance spectrometry. In addition, BHE exhibited scavenging activity against the 1,1-diphenyl-2-picrylhydrazyl radical and intracellular reactive oxygen species (ROS) that were induced by either hydrogen peroxide or UVB radiation. BHE reduced UVB-induced apoptosis, as shown by decreased apoptotic body formation and DNA fragmentation. BHE also attenuated DNA damage and the elevated levels of 8-isoprostane and protein carbonyls resulting from UVB-mediated oxidative stress. Furthermore, BHE absorbed electromagnetic radiation in the UVB range (280–320 nm). These results suggest that BHE protects human HaCaT keratinocytes against UVB-induced oxidative damage by scavenging ROS and absorbing UVB photons, thereby reducing injury to cellular components.     

Inhibitory effects of <Emphasis Type="SmallCaps">l</Emphasis>-pipecolic acid from the edible mushroom, <Emphasis Type="Italic">Sarcodon aspratus</Emphasis>, on angiotensin I-converting enzyme

The aqueous extract of the edible mushroom Sarcodon aspratus showed inhibitory effects against angiotensin I-converting enzyme (ACE). l-Pipecolic acid (l-piperidine-2-carboxylic acid) was isolated from a hot-water extract in a 0.02% yield as an active principle. The mode of inhibition of l-pipecolic acid was found to be competitive, whereas its d-isomer showed no significant inhibitory effects against ACE, suggesting that the configuration of the carboxyl group in the molecule plays an important role in the enzyme inhibition.     

Integrated nutrient management for environmental-friendly rice production in salt-affected rice paddy fields of Saemangeum reclaimed land of South Korea

This study was conducted in an attempt to determine the proper nitrogen and phosphorus application levels, nitrogen split application ratio, and application method for environmental-friendly rice production in a salt-affected rice paddy field, which was located in the Saemangeum reclaimed tidal belt on the western coast of South Korea, between April 1, 2003 and October 10, 2004. All treatments were replicated three times in a randomized block design (5 m × 4 m plot) with 11 treatments (total 33 plots). We designed three treatments for the evaluation of reasonable application levels of nitrogen and phosphorus fertilizers (A1–A3); five treatments to evaluate the nitrogen split application system (T1–T5); and three treatments to determine the proper application for chemical fertilizer (M1–M3). There was no significant difference of amylose and protein content among the application levels, application methods, and nitrogen split application ratios (P < 0.05). No significant differences in grain yield and yield components of rice were observed among the different application levels, application methods, and nitrogen split application ratios (P < 0.05). In order to save labor in agricultural households, preserve or enhance the grain quality of rice, and reduce nutrient losses, we determined that the optimum application level of nitrogen fertilizer was 140 kg ha⁻¹; the application split ratio of nitrogen fertilizer at four different periods was 40% for basal fertilization, 20% for maximum tilling stage, 30% for the panicle formation stage, and 10% for the booting stage; and the best application methods were deep layer application and whole layer application.     

Surface and subsurface losses of N and P from salt-affected rice paddy fields of Saemangeum reclaimed land in South Korea

The present study was carried out to evaluate nutrient losses that occur during the course of agricultural activity from rice paddy fields of reclaimed tidal flat. For this study, we chose a salt-affected rice paddy field located in the Saemangeum reclaimed tidal area, which is located on the western South Korean coasts. The plot size was 1,000 m² (40 m × 25 m) with three replicates. The soil belonged to the Gwanghwal series, i.e., it was of the coarse silty, mixed, mesic type of Typic Haplaquents (saline alluvial soil). The input quantities of nitrogen and phosphorus (as chemical fertilizer) into the experimental rice paddy field were 200 kg N ha⁻¹ and 51 kg P₂O₅ ha⁻¹ per annum, and the respective input quantities of each due to precipitation were 9.3–12.9 kg N ha⁻¹ and 0.4–0.7 kg P ha⁻¹ per annum. In terms of irrigation water, these input quantities were 4.5–8.2 kg N ha⁻¹ and 0.3–0.9 kg P ha⁻¹ per annum, respectively. Losses of these nutrients due to surface runoff were 22.5–38.1 kg N ha⁻¹ and 0.7–2.2 kg P ha⁻¹ for the year 2003, and 26.8–29.6 kg N ha⁻¹ and 1.6–1.9 kg P ha⁻¹ for the year 2004, respectively. Losses of these nutrients due to subsurface infiltration during the irrigation period were 0.44–0.67 kg N ha⁻¹ and 0.03–0.04 kg P ha⁻¹ for the year 2003, and 0.15–0.16 kg N ha⁻¹ and 0.05–0.06 kg P ha⁻¹ for 2004. When losses of nitrogen and phosphorus were compared to the amount of nutrients supplied by chemical fertilizers, it was found that 11.3–19.1% of nitrogen and 0.5–1.7% of phosphorus were lost via surface runoff, whereas subsurface losses accounted to 0.2–0.8% for nitrogen and only 0.02–0.04% for phosphorus during the 2-year study period.     

Fine structure and physical properties of poly(buthylene terephthalate) sheets prepared by roller drawing method

Poly(butylene terephthalate) sheets were prepared by roller-drawing method with various draw ratio. The drawing temperature is 100 °C and draw ratios were varied 2, 2.5, 3, 3.5 and 4. The effect of draw ratio on the crystal structure, the molecular orientation, dynamic viscoelastic properties, sonic modulus and tensile properties of the roller-drawn PBT sheets were investigated. In WAXD results, with increasing of the draw ratio, (010) and (100) planes of preferred orientation have the strongest intensity on the equator. In the meridional scans, it was confirmed that α and β crystal co-existed in the roller drawn PBT sheets with various draw ratio. Uniaxially roller-drawn PBT sheets clearly increased orientation along the stretched direction at high draw ratio. And the four-methylene groups of PBT orient along the surface of the sheet. The mechanical properties of PBT sheets were improved by orientation-induced crystallization during roller drawing process at 100 °C.     

Application of multibounce attenuated total reflectance fourier transform infrared spectroscopy and chemometrics for determination of aspartame in soft drinks

Aspartame is a low-calorie sweetener commonly used in soft drinks; however, the maximum usage dose is limited by the U.S. Food and Drug Administration. Fourier transform infrared (FTIR) spectroscopy with attenuated total reflectance sampling accessory and partial least-squares regression (PLS) was used for rapid determination of aspartame in soft drinks. On the basis of spectral characterization, the highest R2 value, and lowest PRESS value, the spectral region between 1600 and 1900 cm(-1) was selected for quantitative estimation of aspartame. The potential of FTIR spectroscopy for aspartame quantification was examined and validated by the conventional HPLC method. Using the FTIR method, aspartame contents in four selected carbonated diet soft drinks were found to average from 0.43 to 0.50 mg/mL with prediction errors ranging from 2.4 to 5.7% when compared with HPLC measurements. The developed method also showed a high degree of accuracy because real samples were used for calibration, thus minimizing potential interference errors. The FTIR method developed can be suitably used for routine quality control analysis of aspartame in the beverage-manufacturing sector.     

Evaluation of genetic diversity and relationships within an on-farm collection of Perilla frutescens (L.) Britt. using microsatellite markers

The present study demonstrates utilization of 11 microsatellite markers to explore genetic diversity held in Perilla frutescens (L.) Britt. landrace accessions growing on farms in different parts of Korea and Japan and to assess their genetic relationships. All microsatellite loci were polymorphic and produced a total of 96 alleles ranging from 4 to 20, with an average of 8.7 alleles per locus. Of the 96 alleles found, a total of 15 unique landrace-specific alleles were observed at 9 different loci. The locus GBPFM203 provided the highest number of alleles (20), of which five were unique and each specific to a particular landrace accession. The occurrence of unique, accession-specific alleles presented molecular evidence for the generation of new alleles within on-farm collection of Perilla. The mean values of observed (H _O) and expected heterozygosity (H _E) were 0.39 and 0.68, respectively, indicating a considerable amount of polymorphism within this collection. A genetic distance-based phylogeny grouped the two Perilla varieties, var. frutescens and var. crispa (Thunb.) Decne into two distinct groups. Accessions belonging to var. frutescens could also be divided into two subgroups at a close genetic distance (GD = 0.432). The overall clustering pattern did not strictly follow the grouping of accessions according to their geographic origins. These observations are indicative of extensive germplasm exchange among farms from different geographical regions. The genetic similarity observed among the Perilla landraces may be useful for future Perilla crop variety identification, conservation, and improvement programs.     

Influence mechanism of climate change on paddy farming practices and irrigation water demand

Paddy and Water Environment - Technological and socioeconomic interventions accompanied by climate warming strongly dictate farming practices, lending a direct impact over future irrigation water...