• Title/Summary/Keyword: size difference

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공동캡슐화를 이용한 키토산 분해반응에서 alginate 막의 특성 및 크기에 따른 올리고당의 분자량 내외 분포

  • Lee, Gi-Seon;Choe, Myeong-Rak;Song, Sang-Ho;Im, Hyeon-Su
    • 한국생물공학회:학술대회논문집
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    • 2000.11a
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    • pp.608-611
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    • 2000
  • To separate chitosanoligosaccharides easily by size exclusion, an coencapsulating technology of substrate and enzyme was developed. Chitosan and chitosanase were enveloped in this membrane and the product released to medium by size exclusion. The lower limit of the alginate concentration and the agitation speed were 0.5% and 40 rpm, respectively. Membrane thickness and capsules diameter were $10{\mu}m$ and approx. 3.0mm, 1.5mm, respectively. The molecular weight difference by concentration and cps of alginate were of little significance. And also, the molecular weight of distribution according to enzyme concentration was low concentration of enzyme produced high molecular weight of oligosaccharides. At 1.5mm size of capsule, product diffusion rate to outer part was higher than other capsules. The molecular weight distribution of the released oligosaccharides ranged from 1000 to 6000 Da.

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Optimum Size of a Reef Set in the Southern Water of Korea (한국 남해안의 1개 단위인공어초의 적정 규모)

  • Kim, Chang-Gil;Kim, Ho-Sang;Seo, Jang-Woo;Jung, Geum-Chul
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2006.06a
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    • pp.193-194
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    • 2006
  • This study describes the optimum size of a reef set in Korean coastal waters. Data were analyzed in relation to the weight and variety of fish species caught with a three-layer gill net. The results did not indicate a significant difference in the mean catch and mean number of fish species among the three different reef sets, 800, 1,600 and 2400 $m^3$.

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Development of Specific organ targeting drug delivery system II : Physico-pharaceutical study on the crose-linked albumin microspheres containing cytarabine

  • Kim, Chong-Kook;Lee, Jin-Kyu;Lah, Woon-Lyong
    • Archives of Pharmacal Research
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    • v.9 no.1
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    • pp.39-43
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    • 1986
  • Bovine serum albumin microspheres containing cytarabine were prepared using cross-linking agent, formaldehyde. The shape and the size distribution of them were observed. The shape of them was spherical and the susrface was compact and smooth. The size distribution of them was affected by dispersion forces during emulsfication. The release of cytarabine from albumin microspheres was dependent upon cross-linking time, amount of cross-linking agent and drug/albumin ratio. However, the difference of drug release by the dispersion forces was not great. After release test, the shape of albumin microspheres was nonspherical and the albumin matrix seemed to be a little relaxed. The degradation tests of albumin microspheres by the proteolytic enzyme showed that albumin microspheres were progressively digested according to the cross-linking degree.

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The Effects of Pressure, Wind Velocity, and Diameter of Wet Element on the Measurement of Relative Humidity by a Psychrometer (압력, 풍속 및 습구온도계의 크기가 건습구습도계를 이용한 상대습도 측정에 미치는 영향)

  • Chi, D.S.;Kim, S.T.;Park, C.B.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.2 no.2
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    • pp.137-141
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    • 1990
  • When the relative humidity is measured with an aspirated psychrometer, three factors, which affect the measurement of relative humidity, are atmospheric pressure, the size of wet element and the wind velocity. This paper investigated the effects of the above three factors, and the computer code was developed in order to enhance the accuracy of the relative humidity measurement. As results, it is found that the relative humidity decreases by 6%RH with increasing atmospheric pressure from 650 mbar to 1100 mbar. It is found that the relative humidity drops down when the size of the wet element increases, though the effect of the size of the wet element is not significant. Finally, relative humidity increases with the increasing wind velocity. The difference between the psychrometic table in the present KS and the present results is about 2%RH maximum. As a conclusion, the three factors mentioned above should be considered in order to secure accurate measurement of relative humidity.

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Clinical Observation for Prognosis Utilizing Brain Computerized Tomography Findings and Barthel Index In Acute Cerebral Infarction (급성 뇌경색 환자의 Brain-CT 소견과 Barthel ADL을 이용한 예후에 관한 고찰)

  • Lee, Won-Chul
    • The Journal of Korean Medicine
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    • v.18 no.2
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    • pp.316-325
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    • 1997
  • In a 36-month period, 23 selected Patients with Acute Cerebral Infarction were studied utilizing Computerized Tomography, Barthel Index in an attempt to correlate Brain Computerized Tomography findings with 1week, 4weeks rehabilitation and evaluate the influences of the size and location of the lesion. The study suggested that the size of the lesion had impact on 4 weeks rehabilitation. There was significant different between the patients with Middle Cerebral Artery Pial Territory Infarction(I.P.B.M.C.A.) lesion and the patients with Lacunar Infarction(L.I.), Striatocapsular Infarction(S.C.I.), Internal Watershed Infarction(I.W.I.) lesion, but there was no significant difference between the patients with L.I. lesion and the patients with S.C.I. lesion and the patients with I.W.I. lesion. The size and location of the lesion should be considered together in predicting the functional outcomes of Acute Cerebral Infarction.

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A Study on Ventilation Performance driven by Wind Force in Underground Parking Lots of Apartment - Influence of Opening Size and Surrounding Building - (공동주택 지하주차장의 풍력환기 성능에 관한 연구 - 환기구 면적 및 주변건물의 영향 -)

  • Roh, Ji Woong
    • KIEAE Journal
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    • v.12 no.1
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    • pp.29-34
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    • 2012
  • As a series of studies about natural ventilation driven by wind in basement parking lots of apartment, the influence of opening size and surrounding buildings on ventilation rate was analyzed. Natural ventilation in underground parking lots almost rely on wind than temperature difference. To investigate natural ventilation driven by wind, wind tunnel tests by using scale model and tracer gas method were conducted. $CO_2$-gas concentration was measured, natural ventilation rates were calculated. The experimental results showed that the natural ventilation rate is more reliable to wind direction and surrounding building than opening size and distance between buildings. It was verified that surrounding buildings play a principal role in increasing air flow rate by accelerating wind speed, and growing turbulence intensity. And it showed that ventilation performance is able to be increased by oblique wind to entrance ramp than head on wind in underground parking lots with surrounding buildings.

Reproductive Pattern of the Epifaunal Amphipod Pontogeneia rostrata (Crustacea) on Dolsando Sandy Shore in Korea

  • Yu, Ok-Hwan;Jeong, Seung-Jin;Suh, Hae-Lip
    • Ocean Science Journal
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    • v.43 no.3
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    • pp.127-133
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    • 2008
  • Reproductive patterns of an epifaunal amphipod, Pontogeneia rostrata, were studied on Dolsando sandy shore in Korea. The life history pattern was iteroparous, with recruitment mainly occurring from winter to spring. The sex ratio was malebiased, especially during breeding periods. The mean body length of females was significantly larger than that of males. Brood size and egg volume were positively related to the body length of ovigerous females. There was no significant difference in brood size between successive breeding periods, but egg volumes were significantly higher in early winter (December) than in late spring breeding (May and June), increasing the probability of survival to hatching. These traits contribute to more reproductive potential in early winter than in late spring breeding. The mean brood size of epifaunal P. rostrata was larger but the mean egg volume smaller than that of infaunal amphipods in this sampling area. We suggest that reproductive effort for epifaunal species may be proportionally greater than for infaunal species in risky environments.

Comparison of Size Distributions of Rice Flour Measured by Microscope, Sieve, Coulter counter, and Aerodynamic Methods (현미경법, 표준체법, 전기저항법, 공기역학법에 의한 쌀가루의 입도분포의 비교)

  • Kim, Young-Jin;Kim, Sang-Sook
    • Korean Journal of Food Science and Technology
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    • v.26 no.2
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    • pp.184-187
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    • 1994
  • Size distributions of rice flour measured by microscope, sieve, Coulter counter (electrozone) and aerodynamic (Aerosizer) methods were compared. Among the particle sizes measured by four methods, those by microscope and sieve were the smallest and the largest, respectively. Difference was found between the particle sizes measured by Coulter counter and aerodynamic methods.

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Study on moisture transport in concrete in atmospheric environment

  • Zhang, Weiping;Tong, Fei;Gu, Xianglin;Xi, Yunping
    • Computers and Concrete
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    • v.16 no.5
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    • pp.775-793
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    • 2015
  • Moisture transport in concrete in atmospheric environment was studied in this paper. Based on the simplified formula of the thickness of the adsorbed layer, the pore-size distribution function of cement paste was calculated utilizing the water adsorption isotherms. Taking into consideration of the hysteresis effect in cement paste, the moisture diffusivity of cement paste was obtained by the integration of the pore-size distribution. Concrete is regarded as a two-phase composite with cement paste and aggregate, neglecting the moisture diffusivity of aggregate, then moisture diffusivity of concrete was evaluated using the composite theory. Finally, numerical simulation of humidity response during both wetting and drying process was carried out by the finite difference method of partial differential equation for moisture transport, and the numerical results well capture the trend of the measured data.

Effects of Cyclic Structure of Ammonium Ions on Capacitance in Electrochemical Double Layer Supercapacitors

  • Hong, Jeehoon;Hwang, Byunghyun;Lee, Junghye;Kim, Ketack
    • Journal of Electrochemical Science and Technology
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    • v.8 no.1
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    • pp.1-6
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    • 2017
  • The conductivity of the electrolyte used plays a critical role in the optimization of the performance of electrochemical double layer capacitors. However, when the difference in the conductivities of different electrolytes is not significant (only 10-20%), the conductivity has little effect on the capacitance. On the other, unlike the conductivity and viscosity of the electrolyte, the cation size directly influences the capacitance. Cyclic ions have a smaller effective radius than that of the corresponding acyclic ions because the acyclic alkyl groups have a greater number of conformational degrees of freedom, such as the rotational, bending, and stretching modes. Consequently, because of the smaller effective size of the cyclic ions, cells containing electrolytes with such ions exhibit higher capacitances than do those with their acyclic counterparts.