• Fibers and Polymers
• /
• v.6 no.4
• /
• pp.339-342
• /
• 2005

In this paper, a hand-operating method (tiled test method) of the wool-blending sample is made out, and make use of the method, the test of wool-blending bundle in different blending ratio is accomplished. According to the test data, the synthesis method of the stretch curve is worked out and the synthesis software for the typical stretch curve of wool-blending bundle is designed. Through laboratory hand-operating method, the blending fasciculus applying to fiber bundle test can be obtained in a short time. Calculation for sampling is accomplished in the article. We bring up 9 new signs to describe the characteristics of the curve behind peak for the first time: elongation behind peak (HE), elongation percentage behind peak (HEP), relative elongation rate behind peak (RHE), total break work $(W_a)$, break work behind peak (HW), break work coefficient behind peak (HWC), elongation percentage of half-load behind peak (HEL), load percentage of half-elongation behind peak (HLE), break efficiency behind peak (HEC).

• Journal of Bio-Environment Control
• /
• v.16 no.4
• /
• pp.407-414
• /
• 2007

In order to evaluate the physicochemical properties of sludge compost and to identify the effects water-extracts from sludge compost in 2, 6, 8, 12 weeks of decomposing process on seed germination and root elongation in cabbage, lettuce, soybean and barley plants was investigated. The content of total nitrogen in sludge compost increased slightly in 6 weeks decomposing process, and then decreased gradually. Organic matter content decreased continuously overall decomposing process. As decomposition was processing, pH of sludge compost decreased slightly, and EC increase within 6 weeks decomposing process, and then decreased. The content of nitrogen in water-extracts from sludge compost increased within 8 weeks decomposing process and decreased in 12 weeks decomposing process. The content of ammonium nitrogen was similar with that of total nitrogen, and the ratio of ammonium and nitrate increased within 8 weeks, and then decreased. Cation content and EC decreased the late of decomposing process and pH didn't change. The water-extracts from sludge compost during decomposing process inhibited seed germination and root elongation in cabbage (Brassica campestris), lettuce (Lactuca sativa), barley (Hordeum vulgare) and soybean (Glycine max). The inhibition of root elongation in cabbage was greater than that of relative seed germination, whereas relative seed germination in lettuce was more inhibit than root elongation. Relative seed germination and root elongation in soybean were inhibited slightly, but those of in barley was inhibited strongly. In this study, we would identify the effects of water-extracts from sludge compost on seed germination and root elongation was different to the species of seed. The inhibition of seed germination and root elongation treated with the water-extracts which extracted from sludge compost in the early stage of decomposing process was greater than that of in the late stage of decomposing process.

• Plant Resources
• /
• v.7 no.1
• /
• pp.77-86
• /
• 2004

The reduced ratio of red:far-red (R:FR) light acts as a measure of the proximity of competitors and plants can detect the potentially competing neighbor plants by perceiving reflected R:FR signals and initiate the response of “shade avoidance” before actual shading occurs. The phytochrome system is responsible for monitoring the changes in the R:FR and initiating the shade avoidance response. The response to low R:FR ratio was studied in a white aspen Populus alba clone ‘Bolleana’ using two filter systems: a clear plastic filter system that allows a R:FR ratio less than 1.0 to pass from adjacent border plant reflection; and a special commercial plastic that blocks FR light and creates a R:FR ratio above 3.0. The reduced R:FR signals enhanced the stem elongation in response to competition at the expense of relative stem diameter growth. Trees grown inside clear chambers were 27 ％ taller than trees grown inside the FR-blocking filter chambers. Stem taper of clear chamber trees was 16％ less than the FR-blocking filter trees. Low R:FR also induced 22％ more stem dry weight and 13％ greater petiole length per leaf compared to the FR-blocking filter trees. There were no statistically significant differences in leaf area, leaf number increment, and total dry weight between the two light filter treatments.

• The Korean Journal of Ecology
• /
• v.14 no.2
• /
• pp.121-135
• /
• 1991

A number of laboratory experimentes have performed to elucidate water-soluble of volatile substances from wormwood plant(artemisia princeps var. orientalis) as growth inhibitor or phytotoxicant. in germination tests with aqueous extracts of leaves, stems and roots of the wormwood plants, most tested species showed that relative germination ratio was inversely proportional to comcentration of the extracats. and seedling elongation and dry weight of the species were heavily inhibited with the extracts, incubated leaves, volatile substances of the leaves and soil underneath wormwood plants. gas Chromatography was employed to find out possible phytotoxic substances or growth inhibitors of wormwood leaves. ten substantes have isolated, and most of them were identified as terpenoids.

• The Korean Journal of Ecology
• /
• v.24 no.3
• /
• pp.125-130
• /
• 2001

The allelopathic effects of aqueous extracts from Trifolium repens were studied. Aqueous extracts of leaves, stems, roots and flowers of T. repens strongly inhibited the seed germination and seedling growth of Zoysia japonica. In general, the higher concentration of the extracts showed the more great inhibition effect. The phenolic compounds extracted from T repens were analysed and identified using gas chromatography. 14 phenolic compounds were isolated from the leaves, stems, roots and flowers: caffeic acid, p-hydroxy benzoic acid, ferulic acid, gallic acid, p-coumaric acid, vanillic acid, trans-cinnamic acid, 2,5 dihydroxy benzoic acid, syringic acid, 2-hydroxy cinnamic acid, benzoic acid, salicylic acid, phloroglucinol and phanylacetic acid. The seed germination and relative growth ratio of Z. japonica by 14 phenolic compounds were inhibited in whole treatment. Stronger growth inhibitor were benzoic acid, salicylic acid and trans-cinnamic acid. From these results it is suggested that the phenolic compounds from T. repens seemed to be responsible for the allelopathic potential.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.2 no.3
• /
• pp.62-69
• /
• 1998

Mechanical properties of polyethyleneglycol(PEG)/cyclo-tetramethylene tetranitramine(HMX) propellant were studied by adding polycaprolactone(PCP) and silane derivatives as coupling agent. Mechanical properties of the propellant were enhanced by increasing the content of PCP which was partially replaced with PEG. PCP/HMX propellant showed 17% increase in maximum tensile strength and 59% increase in elongation compared to those of PEG/HMX propellant. However, as the content of PCP was increased, the hydrolytic stability of this propellant was found to be deteriorated due to the ester group of PCP by measuring hardness drop of cured propellant and swell ratio difference of PEG/PCP binder stored at $40^{\cire}C$ and 90% relative humidity. Hardness of the PEG/PCP/HMX propellant was decreased with increasing triethoxysilyl propionitrile(TESPN) and dinitrosalicylic acid (DNSA) content from accelerated aging at $60^{\cire}C$.

• Electrical & Electronic Materials
• /
• v.10 no.1
• /
• pp.54-60
• /
• 1997

The electrical and electromagnetic shielding properties have been investigated in polyaniline free standing films with different degrees of elongation cast from N-methyl 2-pyrrolidone(NMP) solution and camphorsulfonic acid(HCSA) doped polyaniline film. The degree of crystallinity of the crosslinked films increased with increasing the draw ratio. For the case of the oriented films doped with hydrochloric acid, we have the values of conductivities up to 173 S/cm. It is considered that the physical micro-crystalline crosslinking domains act as nucleation sites for the increase of relative crystallinity during stretching. We have obtained the value of conductivity 210 S/cm in the HCSA doped polyaniline film cast from the solvent of m-cresol, which is higher than that of the crosslinking oriented films. The electromagnetic shielding efficiency of HCSA doped polyaniline film obtained 37-41 dB in the frequency range of 10MHz-1GHlz, which is higher than that of the crosslinking oriented films. The higher value of electromagnetic shielding efficiency of HCSA doped polyaniline film suggests strong possibility of electromagnetic shielding material.

• Smart Structures and Systems
• /
• v.30 no.3
• /
• pp.245-253
• /
• 2022

A two-layer beam consisting of an elastoplastic layer and a functional layer made of shape memory alloy (SMA) TiNi is considered. Constitutive relations for SMA are set by a microstructural model capable to calculate strain increment produced by arbitrary increments of stress and temperature. This model exploits the approximation of small strains. The equations to calculate the variations of the strain and the internal variables are based on the experimentally registered temperature kinetics of the martensitic transformations with an account of the crystallographic features of the transformation and the laws of equilibrium thermodynamics. Stress and phase distributions over the beam height are calculated by steps, by solving on each step the boundary-value problem for given increments of the bending moment (or curvature) and the tensile force (or relative elongation). Simplifying Bernoulli's hypotheses are applied. The temperature is considered homogeneous. The first stage of the numerical experiment is modeling of preliminary deformation of the beam by bending or stretching at a temperature corresponding to the martensitic state of the SMA layer. The second stage simulates heating and subsequent cooling across the temperature interval of the martensitic transformation. The curvature variation depends both on the total thickness of the beam and on the ratio of the layer's thicknesses.

• Korean Journal of Environmental Agriculture
• /
• v.24 no.4
• /
• pp.391-397
• /
• 2005

This study was carried out to examine the allelopathic effect of the aqueous extract of Hypochaeris radicata L. on growth of three gramineous forage crops, tall fescue, perennial ryegrass and italian ryegrass. The result on relative elongation ration (RER) of gramineous forage crops treated with the aqueous extract of Hypochaeris radicata L. and the change of quantity generally indicated the inhibitory effect. The inhibitory effect was increased as its concentration was increased. As a result, it is ascertained that the aqueous extract of Hypochaeris radicata L. has allelopathy effect. According to the chemical experiment of the allelochemical substances in Hypochaeris radicata L. by HPLC, there are the differences at each part of plants. However, it is ascertained that there are eleven phenolic compounds, ${\rho}-hydroxybenzoic$ acid, chlorogenic acid, catechin, caffeic acid, syringic acid, salicylic acid, ${\rho}-coumaric$ acid, ferulic acid, hesperidin, trans-cinnamic acid and naringenin. Especially three phenolic acids such as caffeic acid, ferulic acid and naringenin were detected from all part of the plant.

• Journal of Bio-Environment Control
• /
• v.29 no.4
• /
• pp.365-372
• /
• 2020

This study was conducted to compare the effects of foliar spray and sub-irrigation of the triazole fungicide diniconazole on the regulation of stem elongation and to investigate the stimulation of root system development during the seedling stage. Comparing the two application approaches, there were significant differences in the leaf area, leaf area ratio (LAR), plant height, compactness, fresh shoot and root production, relative growth rate (RGR), and root to shoot ratio (R/S). At the same application concentration, the sub-irrigation showed a better retarding effect on growth than the foliar spray, because the PGR activity of diniconazole in root absorption was higher than that in shoot absorption. For reaching a target of 20% to 30% inhibition rate of stem length, foliar application concentration of diniconazole exceeded 10, however, only approximately 1 was required in the sub-irrigation application. The root system of tomato seedlings responded strongly to diniconazole application. Total root length, root volume, root average diameter, and the number of root tips increased when diniconazole was sub-irrigation application at 1. A reduction in fine roots (diameter range of 0 to 0.3 mm) and an increase in the roots with a diameter range of 0.3 to 0.6 mm was observed, and this may contribute to the increase in average diameter. The increase in root average diameter may be positive because root penetration increases with root diameter. Our results suggested that sub-irrigation maximized the PGR activity of diniconazole to enhance the retarding effect. And it also possible to enhance the tomato seedling root system by diniconazole stimulating with a lower concentration.