• 한국연초학회지
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• 제18권2호
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• pp.138-144
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• 1996

This experiment was conducted to obtain the basic information on the morphological and physiological changes in tobacco leaf during the growth period by measuring the changes of chlorophyll, sugar, lipid and mineral contents in tobacco plant. Leaf length and width have been fully developed at 25 days after leaf emergence. Dry weight was rapidly increased between 10 and 15 days after leaf emergence and reached the highest at 30 days. Crude lipid content, palmitic acid, and the major saturated fatty acid were increased with progressing senescence, while unsaturated fatty acid including linolenic acid was decreased as the senescence was advanced. The total nitrogen content showed the highest value at IS days after leaf emergence. On the other hand, the total sugar content showed the highest value at 45 days after leaf emergence and glucose, fructose and sucrose were decreased with leaf development and increased at the end of senescence. The content of chlorophyll showed the highest value at 15 days after leaf emergence and began to decrease at 30 days after leaf emergence. The contents of p, Cu, Zn, and Fe in tobacco leaves were decreased by the end of senescence after leaf emergence but those of Ca, Mg, and Mn in leaves were increased. Key words : Nicotiana tabacum chlorophyll, fatty acid, senescence.

• 미생물과산업
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• 제19권4호
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• pp.27-31
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• 1993

Certain bacterial species possess the capability of differentiation through several morphogenetic changes which enable them to adapt to certain internal and external stimuli(Losick and Shapiro 1984). Upon induction, cells of A. vinelandii undergo a morphological process which leads to the production of one cyst per cell (Sadoff, 1975). The cysts are considerably resistant to desiccation, which confers a survival advantages upon the organism(Socolofsky and Wyss 1962). Like other prokaryotic differentiations encystment provides a relatively simple model of cellular differentiation. Like in other differentiating bacteria, vegetative growth can be separated from differentiation. Furthermore, the differentiation cycle can be synchronized by specific inducer. There have been a great deal of morphological and physiological studies on this process. However, the mechanisms used to regulate cell differentiation can be clearly defined by careful genetic analysis of the process. Unfortunately, A. vinelandii has proven to be difficult for genetic analysis (Sadoff 1975). For example, it has been shown that a variety of metabolic mutants of Azotobacter speicies are difficult to isolate after mutagenesis with chemical mutagens or UV irradiation. Nevertheless recent advances in molecular genetics in Azotobacter species, especially in the nitrogen fixation research area, appear to be able to overcome this difficulty (Robinson et al. 1986; Kennedy et al. 1986).

• Korea-Australia Rheology Journal
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• 제13권4호
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• pp.189-196
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• 2001

The phase morphology is an important factor in the rheology of immiscible polymer blends. Through its size and shape, the interface between the two phases determines how the components and the interface itself will contribute to the global stresses. Rheological measurements have been used successfully in the past to probe the morphological changes in model blends, particularly for dilute systems. For more concentrated blends only a limited amount of systematic rheological data is available. Here, viscosities and first normal stress differences are presented for a system with nearly Newtonian components, the whole concentration range is covered. The constituent polymers are PDMS and PIB, their viscosity ratio can be changed by varying the temperature. The data reported here have been obtained at 287 K where the viscosities of the two components are identical. By means of relaxation experiments the measured stresses are decomposed into component and interfacial contributions. The concentration dependence is quite different for the two types of contribution. Except for the component contributions to the shear stresses there is no clear indication of the phase inversion. Plotting either the interfacial shear or normal stresses as a function of composition produces in some cases two maxima. The relaxation times of these stresses display a similar concentration dependence. Although the components have the same viscosity, the stress-component curves are not symmetrical with respect to the 50/50 blend. A slight elasticity of one of the components seems to be the cause of this effect. The data for the more concentrated blends at higher shear rates are associated with a fibrillar morphology.

• 한국분말재료학회지
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• 제19권3호
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• pp.220-225
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• 2012

YAG:Ce yellow phosphor particles were synthesized by spray pyrolysis with changing the solution properties and their luminous properties, crystal structure, and morphological changes were studied by using PL measurement, XRD, and SEM analysis. It was clear that the solution properties significantly affected the crystal phase, crystallite size, the PL intensity, and the morphology of YAG:Ce particles. At low calcination temperature, the addition of urea only to the spray solution was helpful to form a pure YAG phase without any impurity phases, as the result, the highest luminescence intensity was achieved at the calcination temperature of $900^{\circ}C$. When the calcination temperatures were larger than $1300^{\circ}C$, however, the YAG particles prepared without any additive showed the highest luminescent intensity. Regardless of the solution conditions, the emission intensity of YAG:Ce particles prepared by spray pyrolysis showed a linear relation with the crystallite size. In terms of the morphology of YAG:Ce particles, the addition of both DCCA and $NH_4OH$ to the spray solution was effective to prepare a spherical and dense structured YAG particles.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1158-1158
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• 2001

Fast and dynamic biochemical, enzymatic and morphological changes occur during the so-called generative development and during the vegetative processes in seeds. The most characteristic biochemical and compositional changes of this period are the formation and decline of storage components or their precursors, the change of their degree in polymerization and an extensive change in water content. The aim of the present study was to detect the maturation processes in seed nondestructively and to verify the applicability of near infrared spectroscopic methods in the measurement of physiological, chemical and biochemical changes in wheat seed. The amount and variation of different water “species” has been changed intensively during maturation. Characteristic changes of three water absorption bands (1920, 1420 and 1150 nm) during maturation were analysed. It was concluded that the free/bound transition of water molecules could be followed sensitively in different region of NIR spectra. Kinetic changes of carbohydrate reserves were characteristic during maturation. An intensive formation and decline of carbohydrate reserves were observed during early stage of maturation (0 -13 days, high energy demand). An accelerated formation of storage carbohydrates (starch) was detected in the second phase of maturation. Five characteristic absorption bands were analysed which were sensitive indicators the changes of carbohydrates occurred during maturation. Precursors of protein synthesis and the synthesis of reserve proteins and their kinetic changes during maturation were followed from NIR spectra qualitative and qualitatively. Dynamic formation of amino acids and the changes of N forms were detected by spectroscopic, chromatographic and by capillary electrophoresis methods. Calibration equations were developed and validated in order to measure the optimal maturation time protein and moisture content of developing wheat seeds. The spectroscopic methods are offering chance and measurement potential in order to detect fine details of physiological processes. The spectra have many hidden details, which can help to understand the biochemical background of processes.

• 생명과학회지
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• 제10권4호
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• pp.408-421
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• 2000

We tried to establish the culture method of the chondrocyte isolated from the epiphyseal cartilage and to investigate morphological changes of chondrocyte cultured with enzyme-digested costal cartilage, the perichondrium and experimentally damaged meniscus of rabbit. De novo chondrocyte pellets were prepared from epiphyseal plates by culturing isolated epiphyseal chondrocytes from 4 week. old rabbits. We morphologically assessed the cartilage formation of the chondrocyte culture with enzyme-digested costal carilage, the perichondrial culture, the cultured chondrocytes transplants into experimentally damaged meniscus of rabbits, the perichondrial culture, the cultured chondrocytes transplants into experimentally damaged meniscus of rabbit. In the 24 days, the epiphyseal chondrocytes maintained the typical phenotypes of the partial nodular cell formation. The 30 days cryopreserved chondrocytes showed abnormal and irregular shape. In the type II collagen added culture, the chondrocytes showed expanded rough endoplasmic reticulum and small and large round-like vesicles of processes. In the type IV collagen added culture, the chondrocytes showed large perinuclear vaculoes and abundant well-developed rough endoplasmic reticulum of processes. In the culture with enzyme- digested costal cartilage and the perichondrial culture, the chondrocytes showed a few swelling rough endoplasmic reticulum and vacuoles. The cultured epiphyseal chondrocytes maintained typical phenotype and the chondrocytes were grown faster and maintained more typical phenotype in the type II and IV collagen added culture. The transformed chondrocytes secreted abundant extracellular matrix in the type II collagen added culture, and showed processes in the type IV collagen added culture. The perichondrial chondrocytes were grown faster and their implants were able to transplant. The cultured chondrocytes transplanted into experimentally damaged meniscus were adapted between the meniscus tissues. And the immunocyto-chemical reaction of the type II collagen of the chondrocytes were found to be maintained. The chondrocytes cultured cartilage. The chondrocytes secreted abundantly. The cultured chondrocytes transplanted into experimentally damaged meniscus changed immature cells into enlarged mature cells with extracellular secretion.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 춘계학술논문집 1부
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• pp.513-516
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• 2011

본 연구에서 NaOH, Acetic acid, Silane 처리는 천연섬유와 matrix간의 계면 결합에 불리하게 작용하는 wax, lignin, hemicellose 등을 제거하기 위한 방법 중의 하나이다. 이러한 화학적 처리에 따른 왕겨분말의 형태학적 변화와 열적특성 변화를 관찰하였다. 전처리 조건으로 농도는 1.5%, 3%, 9%이며 각각 30min, 60min, 90min을 처리하였다. 처리하지 않은 왕겨 분말과 NaOH, Acetic acid, Silane 처리를 한 왕겨 분말의 성분을 Energy dispersive spectroscopy(EDS)로 분석하였으며, Scaning electron microscopy(SEM)으로 표면을 관찰하였다. 표면의 상태가 NaOH, Acetic acid, Silane 처리를 하였던 왕겨 분말이 처리를 하지 않았던 왕겨 분말보다 비교적 깨끗해지고, 크랙이 발생함을 확인하였다. 또한 전처리가 된 상태에서 수분흡수율을 측정하고, 처리를 하지 않은 왕겨 분말과 NaOH, Acetic acid, Silane 처리를 한 왕겨 분말을 Thermogravimetric Analysis(TGA)로 열분석을 실시하였다.

• 패션비즈니스
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• 제12권6호
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• pp.1-10
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• 2008

Public interest in healthy hairs gets growing as damaged hairs are seen more frequently with the generalization of heat permanent waves. For this study, experiments have been conducted to understand the influences on the changes in physical and morphological features of wave forms and damaged hairs, by collecting virgin hairs from the women in their mid-20's, who had not experienced chemical applications, and by dividing the applications of heat perm hair treatments, PPT(for pre-treatment) and LPP(for post-treatment), into the pre-treatment, the post-treatment, the pre & post-treatment, and the non-treatment. For the wave formations, curl waves were investigated by the bare eyes using the pictures taken by a digital camera. For the comparison of physical features, the experiments of tensile strength and elongation were done and their mean values were found. For the observations of morphological features, the pictures were taken by SEM for comparison. As for the findings, regarding the curl wave shapes of hairs, the most even and elastic S curl was formed in the case of non-treatment. In the physical features, both of the tensile strength and elongation showed a decreasing tendency in line with the hair damage levels, and the case of the pre & post-treatment indicated the tendency most similar to the control group. In the morphological features of the cuticle, observed with an SEM, the pre-treatment showed the higher possibility of reducing the cuticle damages than the post-treatment did. LPP was found to play the role of protective membrane for the post-treatment, and the pre & post-treatment turned out to reduce most effectively the cuticle damages.

• Carbon letters
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• 제24권
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• pp.82-89
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• 2017

In this study, composite PAN-based ACNFs embedded with MgO and $MnO_2$ were prepared by the electrospinning method. The resultant pristine ACNFs, ACNF/MgO and $ACNF/MnO_2$ were characterized in terms of their morphological changes, SSA, crystallinity and functional group with FESEM-EDX, the BET method, XRD and FTIR analysis, respectively. Results from this study showed that the SSA of the ACNF/MgO composite ($1893m^2g^{-1}$) is significantly higher than that of the pristine ACNFs and $ACNF/MnO_2$ which is 478 and $430m^2g^{-1}$, respectively. FTIR analysis showed peaks of 476 and $547cm^{-1}$, indicating the presence of MgO and $MnO_2$, respectively. The FESEM micrographs analysis showed a smooth but coarser structure in all the ACNFs. Meanwhile, the ACNF/MgO has the smallest fiber diameter ($314.38{\pm}62.42nm$) compared to other ACNFs. The presence of MgO and $MnO_2$ inside the ACNFs was also confirmed with EDX analysis as well as XRD. The adsorption capacities of each ACNF toward $CH_4$ were tested with the volumetric adsorption method in which the ACNF/MgO exhibited the highest $CH_4$ adsorption up to $2.39mmol\;g^{-1}$. Meanwhile, all the ACNF samples followed the pseudo-second order kinetic model with a $R^2$ up to 0.9996.

• 한국염색가공학회지
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• 제24권3호
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• pp.204-212
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• 2012

This study was used a thermogravimetric analyzer to determine thermal characteristics, a hair analysis system to examine morphological changes of wefts-human hair, poly vinyl chloride(PVC) and polyethylene terephthalate (PET)-used in manufacturing wigs. According to a flammability test on human hair and synthetic wefts for wigs, the best results were observed in human hair. According to a thermal test, PET was the best in terms of thermal stability. Also good tensile strength was observed as well. In a scanning electron microscope observation, no human hair scale layer was found because of chemical treatment. In the PVC sample, homogeneous unevenness was observed. Due to a lack of human hair supply and increase in its price, recently, PET weft has emerged as a great substitution for human hair. Because it can be curled using an electric curling device and is more efficient than the conventional non-flammable material PVC in terms of thermal resistance, it will become the next-generation weft for wigs.