• Geomechanics and Engineering
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• 제25권3호
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• pp.245-251
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• 2021

The present study investigated the ageing effect on compressibility, permeability and shear strength behavior of kaolin and bentonite samples in the presence of NaCl and CaCl₂ solutions. The compressibility, permeability and shear strength parameters were determined on the 60, 190, and 250 days cured samples. The results have shown that, the kaolin sample becomes more compressible in the presence Ca²⁺ ions with ageing. Generally, the normalized compression index values of bentonite samples increased at the end of 60 days and 250 days curing time periods. The normalized permeability value of kaolin decreased by ageing in the presence of Na⁺ ions almost twofold. The permeability values of bentonite increased both in NaCl and CaCl₂ solutions during ageing. In the presence of Na⁺ ions kaolin had higher max. shear stress value than Ca²⁺ ions. When the max. shear stress values of 0, 60 and 190 days samples were compared, it was seen that NaCl solution had no significant effect on the shear strength of kaolin sample. However, the shear strength of kaolin increased in the CaCl₂ solution during ageing. In the presence of Ca²⁺ ions the max. shear stress value of bentonite was higher. The results of this study have shown that ageing has significant effects on the compressibility, permeability and shear strength of kaolinitic and bentonitic clayey soils.

• Journal of Forest and Environmental Science
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• 제29권4호
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• pp.282-291
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• 2013

Rapid loss in viability of neem (Azadirachta indica A. Juss.) seed is a major problem. Present effort was undertaken for developing a set pattern for assessing of viability and vigour in seed of various mother tree age of neem (Age I-06 years, Age II-15 years, Age III-25 years and Age IV->30 years old). Various viability test viz. triphenyle tetrazolium chloride test, electrical conductivity, excised embryo test, and germination test have been performed on seeds obtained from mother tree age classes. Inconsistency was observed with the TTC and EC test in germination of seed in laboratory as well as nursery. While various vigour tests viz. cold test, chemical stress test (methanol stress test), and accelerated ageing test alongwith ageing index, germination test (G%, MGT and GV) and various seedling growth parameters like seedling length (cm), number of leaves, collar diameter (cm), total biomass (g) alongwith mathematical indices i.e. vigour index, sturdiness quotient, volume index, quality index, root shoot ratio in nursery as well have been taken for study and showed better consistency. On the basis present study results of various viability and vigour test indicated that mother tree age class II performed better in comparison to others and it can be recommended for seed collection. Further it is also recommended that viability of neem seed may be assessed using various laboratory tests like excise embryo test and germination test (G%, MGT and GV) and vigour test may be taken preferably by cold germination test, chemical (methanol) stress test, accelerated ageing test in laboratory and germination alongwith various seedling growth parameters seedling length (cm), number of leaves, collar diameter (cm), total biomass (g) alongwith mathematical indices like Vigour Index, Sturdiness quotient, Volume Index, Quality index, root shoot ratio in nursery as discussed in this study.

• 한국주조공학회지
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• 제38권5호
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• pp.95-102
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• 2018

The dependence of the tensile properties on variations in the porosity of A356 aluminium alloys was investigated in terms of the quality index of the tensile properties based upon the ultimate tensile strength and elongation as well as the variation of the strength coefficient and strain-hardening exponent with regard to a T6 treatment. The test specimens were prepared by low-pressure die-casting and a subsequent T6 treatment, and the experimental results of a tensile test carried out at room temperature were compared to the theoretical description using a modified constitutive model. The nominal value of the quality index of A356 alloys increases gradually with a lapse of the ageing time upon a T6 treatment, despite the fact that this value is temporarily decreased during the initial stage of ageing from a solutionised condition. Additionally, the quality index depends practically upon the porosity variation with a power law relationship without regard to whether in solutionised or artificial aged conditions. The theoretical description indicates that the strength coefficient directly determines the nominal level of the quality index. Moreover, the overall dependence of the quality index on the porosity variation is remarkably weakened with an increase in the tensile strain, whereas the quality index depends sensitively upon the porosity variation with a low value of the strain-hardening exponent.

• 펄프종이기술
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• 제43권2호
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• pp.40-48
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• 2011

To build up the conservativeness of aged paper heritages, the strength reinforcement treatment using various cellulose derivative solutions was considered. Hand-made Hanji prepared by traditional papermaking technique was firstly simulated in order to modify the overall of paper properties like aged paper heritages by accelerated ageing treatment at $150^{\circ}C$ for 24 hours, and then the ageing stability of Hanji was verified through the secondary accelerated ageing at $150^{\circ}C$ for 12 hours. The physical properties of aged Hanji were improved by applying with cellulose derivative solutions. The ageing stability for physical, optical (L, brightness, opacity, yellowness) and chemical (oxidation index, degree of polymerization) properties of aged Hanji treated with all kinds of cellulose derivative solutions was also good compared to those of untreated samples, especially using MC solution. Therefore, it was that a kind of MC solution would be well-suited for the strength reinforcement treatment of aged paper heritages.

• 보존과학회지
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• 제36권1호
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• pp.1-14
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• 2020

This study investigates the crystallinity distribution of ancient silk. Owing to the inherent multi-hierarchical structure of silk protein and the complicated structural changes that occur due to various burial environments, it is challenging but worthwhile to study ancient silk ageing behavior, which is based on the fact that ageing begins with a single fiber and then spreads to a whole fabric. Crystallinity was one of the most effective indicators found to reveal the ageing status of silk. Therefore, a synchrotron radiation-based X-ray diffraction(SR-XRD) method was employed to study the crystallinity distribution of single fibers of ancient silk unearthed from seven archaeological sites in China from historical periods including the warring states, Han dynasty, Song dynasty, and Ming dynasty. In comparison, the conventional X-ray diffraction method, which uses large amounts of samples, was also performed to determine the integral crystallinity of ancient silk. Thermal stability experiments by thermogravimetry(TG) as well as morphology observations by scanning electron microscopy(SEM) and optical microscopy(OM) all confirmed the deterioration of ancient silk. Moreover, the ageing mechanism of ancient silk was proposed with the assistance of an artificial ageing study. The results confirmed the effectiveness of SR-XRD as an ageing indicator, revealing the crystallinity distribution. This research could provide motivation to determine the deterioration status of ancient silk, and would also aid in explaining the fragility of ancient silk due to ageing.

• 펄프종이기술
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• 제40권1호
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• pp.55-61
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• 2008

The annals of Joseon Dynasty is the most valuable resource containing the record of Korean history and has been known as one of the UNESCO's Memory of the World Register. In some period, wax-treated paper was used in the annals of Joseon Dynasty to prevent the damage from pests. But, wax-treated volumes were discolored to brown, white or black, and partially cracked by the stiffened wax. It means that wax-treated volumes were damaged by the hardening and oxidizing of wax. The wax is considered as the first reason in damages on the wax-treated volume. Therefore, in this study we analysed the oxidation index of Korea traditional paper(Hanji) which is used as the restoration paper of the waxed volume in the annals of Joseon Dynasty by using FT-IR. As the analysis of FT-IR, the traditional two-layed stamping paper (Hanji sample F), which was treated by starch in its surface, was shown the most stable state after the accelerated ageing test.

• 한국의류학회지
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• 제20권6호
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• pp.962-974
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• 1996

This study aimed to provide basic data in designing clothes for the elderly women. The subjects in this study were 230 elderly women over sixty years old. The major objectives of this study were as follow; 1 Categorization of the subjects based on their age and Rohrer index. 2. Relationship between age and body cathexis. 3. Relationship between age and clothing size satisfaction. 4. Relationship between age and clothing attitudes. The results were as follows; 1. Height decreased while bust, waist and hip circumstances increased with ageing. 2. All subjects were dissatisfied with their body changes associated with ageing. 3. The women over seventy years old were more dissatisfied with apparel size than those in the sixties. Especially the women aged over 75 complained the back length and the crotch length. 4. The elderly wowed were insterested in sewing condition, size and comfort with ageing even though they considered color and design as the most important attribute in selections clothes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2408-2410
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• 1999

The ageing process was checked by leakage current monitoring in Inclined-Plane Method. In order to monitor leakage current, DAS with 12-bit, 8-channel A/D converter was prepared. The monitored components of leakage current were averages of the rms and peak, max peak, cumulative charge, and the number of peaks in the ranges of 1-10, 10-20, 20-30, 30-40, 40-50, >50 mA. And, erosion depth was measured to be used as the index of the ageing. So, the results of leakage current components and erosion depth measurement were compared to find one or more components of which trends of changes were similar to that of erosion.

• 한국산림과학회지
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• 제103권4호
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• pp.670-678
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• 2014

이 연구는 코호트 변화율법을 이용하여 우리나라 산촌지역 인구변동의 특성을 분석하고 장래 산촌인구를 추계한 것이다. 분석대상이 되는 산촌은 산림청에서 지정한 산촌진흥지역으로, 산림면적 비율 70% 이상, 인구밀도 111인/$km^2$, 경지면적 비율 21% 이하인 읍 면으로 정의한다. 산촌의 인구변동 특성을 살펴보면 지난 20년 간 산촌 인구는 급격히 감소하였고 노령화 지수는 상승하였다. 연령별로는 10~30대 젊은 층의 인구 유출이 많고 40대 이상 장년층의 유입이 증가하였다. 젊은 세대 인구가 감소하는 것은 교육과 취업을 위해 도시로 이동하는 경우가 많기 때문이며, 장년층 인구 증가는 귀농 귀촌에 대한 관심 증대의 영향으로 생각된다. 이러한 추세가 지속된다면 산촌인구는 2030년에 68만 명, 산촌의 노령화 지수는 1,035로 상승하여 국토의 균형 발전과 산림의 지속가능한 경영에 문제를 초래할 것이다. 따라서 산촌경제 활성화와 안정화를 위한 정책적 개입이 필요하다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권7호
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• pp.1021-1028
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• 2017

Objective: The objective of this study was to evaluate the effects of ageing time of lamb loins prior to freezing on technological characteristics and oxidation stability of coarse ground lamb loin sausage using in a model system. Methods: Lamb loins (M. longissimus lumborum, n = 25) were aged at $-1.5^{\circ}C$ for 0, 1, 2, 3, and 8 wk and then frozen for the remaining days (a total of 30 wk). The aged/frozen/thawed lamb loins were ground, and model sausages were formulated with 75% aged/frozen/thawed lamb loin, 25% water, 1.5% sodium chloride (NaCl) and 0.3% sodium tripolyphosphate. The pH and thaw/purge loss of aged/frozen/thawed lamb loins were evaluated, and protein functionality (protein solubility and emulsifying capacity), water-holding capacity and textural properties of model sausages were determined. Cooked model sausages were vacuum-packaged in a plastic bag and displayed under continuous fluorescent natural white light ($3^{\circ}C{\pm}1^{\circ}C$). Colour and lipid oxidation of the cooked model sausages were evaluated on 0 and 21 d of display storage. Results: Ageing prior to freezing had no impact on pH and purge/thaw loss of lamb loins and the colour of cooked sausages (p>0.05) made from the loins. Lamb loins aged for at least 3 wk prior to freezing numerically improved total and myofibrillar protein solubilities (p>0.05) and emulsion activity index (p = 0.009) of meat batter, but decreased cooking loss (p = 0.003) and lipid oxidation (p<0.05) of model sausages. Conclusion: This study suggests that post-mortem ageing of raw meat prior to freezing could improve water-holding capacity and lipid oxidative stability of sausage made from the meat.