• Title/Summary/Keyword: Property ($C_k$)

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Purification and Biological Characterization of Wild-type and Mutants of a Levan Fructotransferase from Microbacterium sp. AL-210 (Microbacterium sp. A-210이 생성하는 Levan fructotransferase의 정제 및 생물학적 특성에 관한 연구)

  • Hwang, Eun-Young;Jeong, Mi-Suk;Cha, Jae-Ho;Jang, Se-Bok
    • Journal of Life Science
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    • v.19 no.9
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    • pp.1218-1225
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    • 2009
  • Difractose anhydrides (DFAs) is studied as a sweetener for diabetics because of its structural property. DFAs have four types: DFA I, III, IV (degradation of levan) and V (degradation of inulin). Especially, DFA IV has been shown to enhance the absorption of calcium in experiments using rats. Levan fructotransferase is an enzyme for producing di-d-fructose-2,6':6,2-dianhydride (DFA IV). To identify structural characterization, we purified wild-type and mutants (D63A, D195N and N85S) of levan fructotransferase (LFTase) from Microbacterium sp. AL-210. These proteins were purified to apparent homogeneity by Ni-NTA affinity column, Q-sepharose ion exchange and gel filtration chromatography and detected by SDS-PAGE. They were also analyzed by circular dichroism (CD) measurements, JNET secondary structure prediction, activity measurements at various temperatures, and pH analysis. The optimum pH for the enzyme-catalyzed reaction was pH 7.5 and optimum temperature was observed at $55^{\circ}C$. Along with wild-type LFTase, mutants were analyzed by CD measurement, fluorescence analysis and differential scanning calorimetry (DSC). N85S showed less $\alpha$-helix and more $\beta$ strand than others. Also, N85S showed almost the same curve as wild-type in their steady-state fluorescence spectra, whereas mutant D63A and D195N showed higher intensity than wild-type. The amino acid sequence of wild-type LFTase was compared to the sequences of exo-inulinase from Aspergillus awamori, a plant fructan 1-exohydrolase from Cichorium intybus, and Thermotogo maritime (Tm) invertase and showed a high identity with Exo-inulinase from Aspergillus awamori.

A STUDY ON WEAR RESISTANCE OF FLOWABLE COMPOSITE RESINS (유동성 복합레진의 마모저항성에 관한 연구)

  • Yun, Yeon-Hee;Kim, Jung-Wook;Lee, Sang-Hoon;Hahn, Se-Hyun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.29 no.2
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    • pp.217-225
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    • 2002
  • When we use the flowable resin on the primary molars for quick handling, one of the most important property is the wear resistance. This study was performed to compare the wear resistance characteristics of four flowable composite resins [Arabesk flow (group 1), Tetric flow (group 2), Aeliteflow (group 3), Filtek flow (group 4)] to that of one control composite resin [Z100 (group 5)]. Specimen discs(n=10), 10mm wide and 2mm thick, were stored in distilled water at $37^{\circ}C$ for 7 days prior to testing. The specimens were subjected to 50,000 strokes at 2 Hz on the MTS system. During the test, the following parameters were maintained: the lateral excursion at 0.4mm, occlusal force at 2-100N with a force profile in the form of a half sine wave. The measurements of volume loss, depth of wear, and Vicker's hardness number of composite resins, and SEM observations of the polished and abraded surfaces were established. One-way ANOVA and Scheffe's multiple comparison test were employed to detect statistically significant differences among the flowable composite resin groups and the control composite group at P<.05. The following results were obtained: 1. Group 3 showed the least volume loss, while group 4 showed the greatest. The mean volume loss increased in the following order: group 3

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Quality Properties of Tea Extracts Prepared with Persimmon Flowers (감꽃 침출차의 품질 특성)

  • Chung, Hun-Sik;Youn, Kwang-Sup;Seong, Jong-Hwan;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.14 no.2
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    • pp.148-153
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    • 2007
  • The chemical components of flesh persimmon flowers (petal and calyx), and the qualify of hot-water extracts (teas) prepared from powders of these flower parts, were investigated In flesh petal and calyx, the contents of moisture, crude protein, crude lipid, and carbohydrate were 84.8% 0.4% 0.3% and 13.7% respectively. The values were not significantly different when the two tissues were compared. In petal and calyx respectively, the crude ash values were 0.5% and 1.1% of flesh weights, the vitamin C content were 192.3mg% and 392.7ng%, the flavonoid levels were 98.4 mg% and 355.2mg% and the carotenoid content were 0.8mg% and 3.8mg%. Hot air and freeze drying methods applied to petals, prior to powder preparation, did not affect the levels of soluble solids or soluble annins. Extract from calyx had higher L values, higher ${-\alpha}$ values, more soluble tannins, greater 1,1-diphenyl-2-picrylhy-drazylradical-scavenging activities, me lower pH values, than did exracts from petal. Fructose and glucose were higher in petal extract than in calyx extract, but sucrose was higher in calyx extracts. Extract of freeze-dried powdered petals had significantly higher free sugar levels than did exracts from petals dried with hot air. The major organic acids in extracts were citric acid, oxalic acid, and malic acid. The levels of organic acids were inversely related to free sugar levels in all flower parts and after all drying methods tested. Sensory tests of aroma, taste and overall acceptability yielded scores above medium for all teas, regardless of the flower part powdered, or the drying method used. The results show that the petal and calyx of persimmon may be used to make tea and perhaps other foods.

Studies on the Elasticity, Young Modulus, and Breaking Tension of the Tympanic Membrane in Dog (고막(鼓膜)의 탄성도(彈性度)와 파열장력(破裂張力)에 관(關)한 연구(硏究))

  • Lee, Young-Shik
    • The Korean Journal of Physiology
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    • v.2 no.1
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    • pp.39-45
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    • 1968
  • Recently, in this department, pressure-displacement curve and breaking tension of dog and human tympanic membrane were studied using intact, fresh or dried tympanic membrane attached to external auditory meatus. However, physical property, proper elasticity-Young Modulus, of the tympanic membrane has not been clarified yet. Present study is attempted to further clarify proper Young Modulus of tympanic membrane, and to distinguish possible difference between layer of stratum radiatum and layer of stratum circulare of tympanic membrane in breaking tension and in Young Modulus. Tympanic membrane was excised from sacrificed dog, and preparation was made into the size of approximately 1 mm in width and 3 mm in length. In fresh or dried tympanic membrane, which was dried at $80^{\circ}C$ for 24 hrs., some preparations were made along the long axis parallel to the fibers of radial direction, and others were made along the long axis perpendicular to the radial fibers-circular direction. Breaking tension and displacement according to loading, were measured and Young Modulus was calculated in tympanic membrane preparations under the different experimental conditions. Results obtained are summarized as follows : 1. Young Modulus of fresh tympanic membrane in radial direction was $6.57{\times}10^8\;dyne/cm^2$, and that of fresh preparation in circular direction was $1.68{\times}10^8\;dyne/cm^2$. The Young Modulus of fresh tympanic membrane in radial direction resembles to that of silk and whale moustache. In dried tympanic membrane, Young Modulus of preparation of radial direction was $30.2{\times}10^8\;dyne/cm^2$ and that of preparation in circular direction was $25.0{\times}10^8\;dyne/cm^2$. 2. Breaking tension of fresh tympanic membrane was 44.9 gm/mm in radial preparation, and 7.9 gm/mm in circular preparation. In dried tympanic membrane, breaking tension was 46.7 gm/mm in preparation of radial direction, and 17.2 gm/mm in preparation of circular direction. 3. Much smaller breaking tension of the circular preparation-one fifth to the radial preparation-seemed to be responsible for the higher incidence of circular fiber breaking in tympanic membrane performation caused by trauma or sudden change in atmospheric pressure. 4. The correlation seemed to be very close between breaking tension and Young Modulus in tympanic membrane.

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Studies on Plywood Treated Fire-Retardant - III. The Fire-Retardant Degree of Monoammonium Phosphate Treated Plywood (합판(合板)의 내화처리(耐火處理)에 관(關)한 연구(硏究) - III. 제1인산(第一燐酸)암모늄처리합판(處理合板)의 내화도(耐火度))

  • Kim, Jong-Man
    • Journal of the Korean Wood Science and Technology
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    • v.14 no.4
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    • pp.21-28
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    • 1986
  • Plywood used for construction as a decorative inner material is inflammable and can fire accident, causing destruction of human life and property. In this study, 3.5mm Kapur plywoods were soaked in the 23% monoammonium phosphate solutions by cold soaking method 3, 6, 9hrs and hot-cold bath method for 3/3hrs, and redrying was carried out by press-drying at the platen temperature of 110, 130, 160, 180$^{\circ}C$, and then fire test was carried out to investigate burning point, flame exhausted length, frame spread length, back side carbonized area and weight loss. The results are as follows; 1. In cold soaking method for 3, 6, 9hrs. retentions of monoammonium phosphate were 0.377, 0.448, 0.498kg/(30cm)$^3$ respectively, and in hot-cold bath method for 3/3hrs, the retention was 1.331kg(30cm)$^3$ that exceeded the minimum retention 1.124kg/(30cm)$^3$. 2. Correlation coefficients among the variable were shown in table 2. From the table, it could be recognized that there were close negative correlations between the treatment and burning point, flame spread length, back side carbonized area, flame exhausted time and weight loss, and there was negative correlation between treating time and back side carbonized area, but there was positive correlation between platen temperature and burning point. 3. From table 3, it can be observed that there were highly significant differences for burning point, flame spread length, flame exhausted time, back side carhonized area, weight loss between treatments. And in 2-way interactions, there were also highly significant for burning point, flame spread length, flame exhausted time, weight loss between time x treatment. 4. It was observed that burning point, flame exhausted time, flame spread length, back side carbonized area, and weight loss in fire-retardant treated plywood were the best effects in fire-retardant treated plywood, water treated plywood and nontreated plywood. In conclusion, I can estimate that absorbed chemical contents by hot-cold bath method for 3/3hrs, have a lot of effects on fire-retardant factors such as burning point, flame spread length, flame exhausted time, backside carbonized area and weight loss, but platen temperatures have a little effects on the fire factors.

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Analyses on the Physical and Electrochemical Properties of Al2O3 Coated LiCoO2 (리튬이차전지용 양극 활물질(LiCoC2)의 표면처리의 특성 분석 및 전기화학적 특성 고찰)

  • Chang, Youn-Han;Choi, Sei-Young
    • Journal of the Korean Electrochemical Society
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    • v.10 no.3
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    • pp.184-189
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    • 2007
  • The importance of secondary battery industry is getting excited according to the development of battery industry as a high efficiency energy supplier of electronic machine of mobile information such as mobile phone, lap-top computer, PDA. It is rasing the interest about security of safety and high efficiency of cathode material for main part of secondary lithium battery. The cathode material which has been used like $LiCoO_2,\;LiMn_2O_4,\;LiNi_xCo_yMn_zO_2,\;LiNi_xCo_yM_zO_2$ (M=Al, Zr, Mg etc.,) the most typical material is $LiCoO_2$. But it is studying the development of substitute such as efficiency amelioration of $LiCoO_2$, thetiary element, olivine element because of the capacity of $LiCoO_2$, the matter of security; especially the betterment of efficiency, security research of safety has been actively processed in domestic and overseas about surface coating treatment of active cathode which is using oxide ($M_xO_3$). This study analyses side effect of battery according to increase of surface treatment, formation of precipitation for reagent condensation, non-reagent residue of oxide ($M_xO_3$) which is remains during the surface treatment of $LiCoO_2$; conducts study of new process, the consideration of the electrochemical property to improve oxide solution of mixing rate, mixture of surface treatment, dryness, calcinations conditionetc.

Estate Planning among the U.S. Elderly - Focusing on Wills - (미국 노인층의 자산 상속 계획 - 유언장 준비를 중심으로 -)

  • Lee Jieun
    • Journal of the Korean Home Economics Association
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    • v.43 no.6 s.208
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    • pp.113-131
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    • 2005
  • The purpose of this study was to investigate older people's planning for estate distribution by examining the factors associated with their will-holding status. This study used data from the 1994 Assets and Health Dynamics among the Oldest Old (AHEAD) Survey, Wave One. The objectives of this study were (a) to establish profiles of older people who have a written will and to compare their financial portfolios across will-holding status; (b) to identify factors that influence the decision to make a will, and (c) to draw implications for family economists, financial educators, planners, and policy makers. The results suggested that a household's financial resources (i.e., liquid and illiquid assets, housing equity, and household income) positively influence the probability of having a will. Older people who resided in a community property state and who were in poor health were less likely to be will-holders than their counterparts, holding financial resources and other variables constant. Demographic characteristics such as age, education, and race, and behavioral characteristic also were significant determinants of the likelihood of having a will. Volunteer participation and charitable contribution, which are proxies for altruism, increased the likelihood of having a will. The probability of having a will also was higher among those who had life insurance and had gwen inter-vivos gifts of more than $\$5,000$ to their children or grandchildren in the past 10 years. On the other hand, the likelihood of having a will declined with increasing number of biological children. From the findings, implications for financial planners and educators were suggested along with directions for future research.

A Proposal on Evacuation Safety in Medical Welfare Facilities for the Elderly: Targeting the Goyang City (노인의료복지시설의 피난안전에 대한 제언: 고양시를 대상으로)

  • Jeong, Keesin
    • Fire Science and Engineering
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    • v.34 no.4
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    • pp.52-58
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    • 2020
  • The number of medical welfare facilities caring for the elderly with paralysis and dementia has been increasing rapidly because of the change in the way of supporting the elderly, stemming from an increase in the number of the elderly and working couples. These medical welfare facilities are usually installed all over the city and are gradually becoming high-rise. Few inmates are capable of making their own decisions in case of fire at night and when there are no escape routes such as ramps for evacuation, leading to massive casualties. This study aimed to identify problems in evacuation in the medical welfare facilities for the elderly in Goyang city. This city has the largest number of medical welfare facilities for the elderly per unit area. The following strategies could aid in better evacuation: secure ramps or bed escape elevators; the bedrooms of the inmates should have one-hour fire resistance; the stairs should have the structure of an enclosed stairway; the necessary apparatus for evacuation, such as an escape chute, should be installed; and, to conclude, a business agreement with neighboring agencies to help inmates escape during the fire. The state should implement necessary measures to protect the lives and property of the people. Rapid implementation of this proposal is necessary for the evacuation safety of an increasing number of medical welfare facilities for the elderly.

Anti-tumor Activity of Protein-bound Polysaccharides Extracted from Mycelia of Lentinus edodes (표고버섯 균사체로부터 추출한 단백다당체의 항암효과)

  • Lee, Byung-Woo;Park, Ki-Moon
    • Korean Journal of Food Science and Technology
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    • v.30 no.3
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    • pp.665-671
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    • 1998
  • Protein-bound polysaccharides (PBP) were extracted from the mycellia of Lentinus edodes SR-1, and their anti-tumor activities and immunopotentiating properties were observed. The amounts of PBP needed to extend the doubling time twofold (1 unit) were found to be 1 mg for mouse leukemic cells $P_{388}\;and\;L_{1210}$; 4.4, 3.6 and 6.6 for bowel cancer cells, HCT-48, HRT-18, HT-29 respectively; and 2.6 mg for liver cancer cell, Hep G2. When $P_{388}\;and\;L_{1210}$ were treated with 4 mg of PBP, more than 90% of the cell number were reduced in 48 hours. However, 9 mg of PBP and 72 hrs of incubation time were needed to obtain the same effect for HRT-18, HT-29, and Hep G2. The significant reduction of cell size was observed as the amount of PBP and the incubation time increased. Mice spleen weight and plaque forming cell number increased when the cancer cells were treated with PBP.

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FFT/IFFT IP Generator for OFDM Modems (OFDM 모뎀용 FFT/IFFT IP 자동 생성기)

  • Lee Jin-Woo;Shin Kyung-Wook;Kim Jong-Whan;Baek Young-Seok;Eo Ik-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.3A
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    • pp.368-376
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    • 2006
  • This paper describes a Fcore_GenSim(Parameterized FFT Core Generation & Simulation Program), which can be used as an essential If(Intellectual Property) in various OFDM modem designs. The Fcore_Gensim is composed of two parts, a parameterized core generator(PFFT_CoreGen) that generates Verilog-HDL models of FFT cores, and a fixed-point FFT simulator(FXP_FFTSim) which can be used to estimate the SQNR performance of the generated cores. The parameters that can be specified for core generation are FFT length in the range of 64 ~2048-point and word-lengths of input/output/internal/twiddle data in the range of 8-b "24-b with 2-b step. Total 43,659 FFT cores can be generated by Fcore_Gensim. In addition, CBFP(Convergent Block Floating Point) scaling can be optionally specified. To achieve an optimized hardware and SQNR performance of the generated core, a hybrid structure of R2SDF and R2SDC stages and a hybrid algorithm of radix-2, radix-2/4, radix-2/4/8 are adopted according to FFT length and CBFP scaling.