• 제목/요약/키워드: characteristic changes

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추출 용매에 따른 애기똥풀 색소의 특성 및 염색성 (Characteristics and Dyeability of Chelidonium majus var. asiaticum Extracts with Different Solvents)

  • 최형열;이정순
    • 한국생활과학회지
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    • 제24권6호
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    • pp.859-871
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    • 2015
  • The purpose of this study is to examine the influence of the pigment characteristic and changes in dying conditions on the dying properties by extracting Chelidonium majus var. asiaticum using distilled water and ethanol as solvents. Changes in dying conditions include variations in dye concentrations, dyeing temperatures and time on dye uptake, and K/S Value was compared according to these changes. Additionally, color changes were observed through mordant. Ultraviolet-visible spectrum was used to investigate the pigment characteristic, and as a result, tannin was identified in distilled-water-extract, whereas berberine and chlorophyll were identified in ethanol-extract. In FT-IR analysis, tannin in distilled-water-extract was verified as hydrolyzable tannin. For ethanol extract, chlorophyll was verified through absorption band of C-H, which is aliphatic spectrum around $2920cm^{-1}$ and $2850cm^{-1}$. From GC/MS analysis, oil components as well as terpine compounds were detected in ethanol-extract, and this, in turn, brings expectation regarding functionality. When dying in silk, dye uptake increased as concentration of the extract increased, and the optimum dyeing temperature and time were $40^{\circ}C$ and 60 minutes respectively. Dyed fabrics' colors were all basically Y-series colors, and adjustment in brightness and revelation of khaki color were also available depending on the type of the mordant. Color fastness, except for washing fastness, was good in silk dyed with distilled-water-extract. Thus, it can be concluded that by selecting the right extracting method and by doing proper dyeing and mordant according to the needs, these dyed fabrics can be used as eco-friendly, functional clothing material.

전기전철기용 전자클러치의 온도 변화에 따른 물리적 특성에 대한 연구 (A study on physical characteristics by temperature changes of electro-magnetic clutch installed in electric point machine)

  • 심재복;온정근;권기진;최영하
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 추계학술대회 논문집
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    • pp.1259-1265
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    • 2004
  • Electro-magnetic clutch which is affected by elements of electric, magnetic and mechanical friction is important that it has a characteristic changes by environmental impact. Expecially, it is equipped in railroad sideway which is bleak external environment. Therefore, this paper investigated affections by temperature changes, which can make out through physical characteristics such as friction torque, minimum slipping torque, rated slipping torque of electro-magnetic dutch.

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알칼라제를 이용한 폴리아미드 섬유의 효소가공 (Enzymatic Treatment of Polyamide Fiber by Alcalase)

  • 송유선;송화순
    • 한국의류학회지
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    • 제35권8호
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    • pp.1006-1013
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    • 2011
  • An enzymatic treatment method using alcalase was introduced to improve the moisture characteristic of the polyamide fiber. The alcalase treatment conditions such as the pH, treatment temperature, enzyme concentration, and treatment time were optimized by measuring the amino groups. The changes in the weight loss, tensile strength, moisture regain, water contact angle (WCA), and water absorption rate of the polyamide fiber with the changes in the alcalase treatment conditions were evaluated. The optimum alcalase treatment conditions for polyamide fiber were found to be a treatment temperature of 50oC, a treatment time of 50 minutes, an alcalase concentration of 10% (owf), and a pH of 7.0. The ethylenediaminetetraacetic acid (EDTA) and L-cysteine accelerated the activity of the enzyme; however, they did not have an effect on the amino group production of the fiber surface. The alcalase treatment of the polyamide fiber improved the fiber's moisture regain, WCA, and absorption rate due to the amino group on the fiber surface. The results showed that the alcalase treatment of polyamide fiber is an effective method to improve the moisture characteristic of the polyamide fiber.

Predicting soil-water characteristic curves of expansive soils relying on correlations

  • Ahmed M. Al-Mahbashi;Muawia Dafalla;Mosleh Al-Shamrani
    • Geomechanics and Engineering
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    • 재33권6호
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    • pp.625-633
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    • 2023
  • The volume changes associated with moisture or suction variation in expansive soils are of geotechnical and geoenvironmental design concern. These changes can impact the performance of infrastructure projects and lightweight structures. Assessment of unsaturated function for these materials leads to better interpretation and understanding, as well as providing accurate and economic design. In this study, expansive soils from different regions of Saudi Arabia were studied for their basic properties including gradation, plasticity and shrinkage, swelling, and consolidation characteristics. The unsaturated soil functions of saturated water content, air-entry values, and residual states were determined by conducting the tests for the entire soil water characteristic curves (SWCC) using different techniques. An attempt has been made to provide a prediction model for unsaturated properties based on the basic properties of these soils. Once the profile of SWCC has been predicted the time and cost for many tests can be saved. These predictions can be utilized in practice for the application of unsaturated soil mechanics on geotechnical and geoenvironmental projects.

불포화의 흙-수분 특성곡선 방정식의 개발 (Development of Equation of the Soil-Water Characteristic Curve for an Unsaturated Soil)

  • 송창섭;임성윤;김명환
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2003년도 학술발표논문집
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    • pp.191-194
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    • 2003
  • The purpose of this paper was to derive soil-water characteristic curve equation for unsaturated soil. To this end, a series of suction measured test was conducted on the selected 4 kinds of soil which is located in Korea, used the modified pressure plate apparatus. From the test results, it was proved that characteristic curve changes according to grain size distribution, size of void and fine grained soil contents. Residual degree of saturation(Sr) was decreased with void ratio and changed with fine grained soil contents, parameter ${\lambda}$ and hr was increased with void ratio. Soil-water characteristic curve equation based on the test result was suggested by void ratio or grain size distribution.

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To Determine the Characteristic Polynomial Coefficients Based On the Transient Response

  • Haeri, Mohammad;Tavazoei, Mohammad Saleh
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.11-15
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    • 2005
  • This paper presents a method to determine the characteristic polynomial of a closed loop all-pole system in order to obtain desired transient response in terms of the overshoot and speed (rising/settling time). The method adjusts the overshoot by doing some changes in the characteristic ratios of the Bessel-Thompson filter. The closed loop speediness is then tuned by suitable choice of the generalized time constant. Simulation results are presented to evaluate the achievements and make comparison with those of a similar method.

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히트싱크의 핀 배열에 따른 냉각특성에 관한 실험적 연구 (An Experimental Study on Cooling Characteristic according to Fin Array of Aluminum Heat Sink)

  • 윤성운;김재열;고가진
    • 한국기계가공학회지
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    • 제17권1호
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    • pp.138-143
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    • 2018
  • In general, the operating temperature of electronic equipment is closely related to product life and reliability, and it is recognized that effectively cooling the parts is an important problem. In this paper, an experimental study on the cooling characteristic according to the pin array of the heat sink is conducted. The experiment on the heat sink was based on the natural convection and temperature distribution changes. The experimental results indicate that the pin array of the heat sink has an effect on the thermoelectric module's cooling characteristic.

최대유통문제에서의 매개변수계획법 (The Paramatric Analysis in Maximum Flow Problem)

  • 정호연
    • 산업경영시스템학회지
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    • 제20권44호
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    • pp.81-92
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    • 1997
  • The purpose of this paper is to develop a method of paramatric analysis that can be applied to an optimal solution of a maximum flow problem. We first define the transformed network corresponding to a given network. In such a network, we conduct paramatric analysis by determining changes in the optimal solution precipitated by changes in the capacity as the arc capacity varies from 0 to infinite. By this method we can easily calculate not only the characteristic region where the given optimal solution remains unchanged, but also the characteristic region where the value of the maximal flow gradually increases or decreases. The proposed method is demonstrated by numerical example.

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최대유통문제의 사후분석 (Postoptimality Analysis of the Maximum Flow Problem)

  • 정호연;안재근;박순달
    • 대한산업공학회지
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    • 제23권4호
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    • pp.825-833
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    • 1997
  • The purpose of this paper is to develop a method of postoptimality analysis that can be applied to an optimal solution of a maximum flow problem. We first use the transformed network corresponding to a given network. In such a network we conduct postoptimality analysis by determining changes in the optimal solution precipitated by changes in the capacity as the arc capacity varies from 0 to infinite. By this method we can easily calculate not only the characteristic region where the given optimal solution remains unchanged, but also the characteristic region where the value of the maximal flow gradually increases or decreases. The proposed method is demonstrated by numerical example.

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