• Title/Summary/Keyword: Anhydrous

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Studies on the Tablet Product Design : Effects of Anhydrous Lactose and Corn Starch on the Preparation of Prednisolone Tablet by Direct Compression Method (정제의 제조설계에 관한 연구 : 직타법에 의한 Prednisolone 정제의 제조에 있어서 무수유당 및 옥수수전분의 영향)

  • 권종원;민신홍;이상의;김용배
    • YAKHAK HOEJI
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    • v.20 no.1
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    • pp.63-69
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    • 1976
  • Prednisolone tablet product design problem was structured as constrained optimization problem and subsequently solved by multiple regression analysis and Lagrangian method of optimixation. Prednisolone was the drug chosen and anhydrous lactose and corn starch were the adjuvants. The effect of anhydrous lactose and corn starch concentrations on tablet hardness, volume, disintegration time and in vitro release rate was studied. The concentrations of anhydrous lactose and corn starch used in this experiment were 30-60 percent and 5-30 percent, respectively. A full second-order (quadratic) model with all possible two-factor interactions was employed. To obtain the values of anhydrous lactose and corn starch which miniumize the in vitro : release time (t$_{60%}$) subject to the constraint on tablet hardness, disintegration time and volume, we solved the Lagrange function. Multiple correlation coefficients for the regression models were correlated at less than 0.05 level and it was found that the optimum concentrations of anhydrous lactose and corn starch were 45 percent and 21 percent, respectively.

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Electrorheological Properties of Anhydrous ER Suspensions Based on Phosphated Cellulose (인산처리 셀룰로오스를 첨가한 비수계 ER 유체의 전기유변학적 특성)

  • 안병길;최웅수;권오관;문탁진
    • Tribology and Lubricants
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    • v.14 no.2
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    • pp.1-9
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    • 1998
  • The electrorheological (ER) behavior of suspensions in silicone oil of phosphated cellulose particles (average particle size 17.77 ${\mu}{\textrm}{m}$) was investigated at room temperature with electric fields up to 2.5 KV/mm. In this paper, for development of anhydrous ER suspensions using at wide temperature range, we would like to know fundamental understandings on the ER activity. As a first step, the anhydrous ER suspensions dispersed the phosphated cellulose particles were measured, and not only the electrical characteristics such as dielectric constant, current density and electrical conductivity but also the rheological properties on strength of electric field and quantity of dispersed phase were studied. From the experimental results, the anhydrous ER suspensions dispersed phosphated cellulose particles showed a stable current density and very high performance of ER effect $(\tau/\tau_0=1030)$ on the 2.5 KV/mm and the dynamic yield stress $(\tau_y)$ was in exponential proportion to the strength of electric fields.

The Effect of Compressing ER Electrode on Electrorheological Properties of Anhydrous ER Fluids (ER 유체용 압축전극이 ER 유체의 전기유변학적 특성에 미치는 영향)

  • Ahn, Byeng-Gil
    • Tribology and Lubricants
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    • v.18 no.1
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    • pp.16-23
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    • 2002
  • For increasing the yield stress of ER fluids, the compressing ER electrode was developed and the compressing electrorheological (ER) behavior of anhydrous ER fluids in silicone oil of phosphorous ester cellulose powder was investigated. Under constant electric field, not only the current density but also the yield stress of anhydrous ER fluids were studied as varying the compressing length of ER electrode distance. From the experimental results the compressing of ER electrode had a large influence to the ER properties of anhydrous ER fluids. The current density was proportional to the compressing length of ER electrode under constant electric field and volume fraction also tile compressing yield stress was proportional to the volume fraction of dispersed particles under constant electric field and compressing length. When the ER electrode was compressed with 150mm after charging the electric field, 4 kV, tile yield stress of phosphoric ester cellulose ER fluids increased to thirteen times comparing with the yield stress measured at normal electrode.

The Effect of the Activation of Phosphoric Ester Cellulose Particles on the Electrotheological Properties of Anhydrous ER Fluids (인산 에스테르 반응 셀룰로오스 미립자의 활성화가 비수계 ER 유체의 전기유변학적 특성에 미치는 영향)

  • 안병길;최웅수;권오관;문탁진
    • Tribology and Lubricants
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    • v.14 no.3
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    • pp.7-16
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    • 1998
  • The electrorheological (ER) behavior of suspensions in silicone oil of phosphoric ester cellulose powder (average particle size: 17.77 $\mu$m) was investigated at room temperature with electric fields up to 2.5 KV/mm. For development of anhydrous ER suspensions using at wide temperature range, we aimed to know the effect of activation of phosphoric ester cellulose particles on the ER activities. As a first step, the anhydrous ER suspensions mixing with the phosphoric ester cellulose particles which were treated with 2M phosporic acid and 4M urea were measured. After activating the anhydrous ER suspensions at 12$0^{\circ}C$, not only the analysis of dispersing cellulose particles which were reacted by phosphoric ester but also the electrorheological characteristics of ER suspensions such as dielectric constant, current density, electrical conductivity and rheological properties were studied. From the experimental results, the activation of phosphoric ester cellulose particles had an influence on the ER properties of anhydrous ER suspensions. As the activation time went by, the size and number of dispersing particles, the electrical properties and the initial apparent viscosity $(η_0)$ of ER suspensions were increased till the activation time passed 5 hours. Also, it was possible, the electrorheological effect $($\tau$/$\tau$_0)$ of ER fluids was grown by the activation of phosphoric ester cellulose particles.

NUTRITIVE VALUES AND GROWTH RESPONSE OF CATTLE FED AMMONIA TREATED RICE STRAW

  • Maeng, W.J.;Chung, T.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.2 no.1
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    • pp.1-6
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    • 1989
  • Nutritive values and fermentation rates of rice straw treated with 3% anhydrous and 3% aqueous ammonia were evaluated both in vitro and sheep metabolism trials. Daily gain, feed efficiency and feed cost per gain were also determined with growing Holstein bulls fed anhydrous and aqueous ammonia treated rice straw. Crude protein was increased 2.4 fold and NDF was decreased 6.5%, but ADF and cellulose were not different between untreated and ammonia treated rice straw. An average of 35.5% of total added ammonia-N retained in the rice straw and other 64.5% was not retained in the rice straw. Ammonia treatment increased in vitro DM, NDF, ADF and cellulose digestibilities by 44.8%, 43.3%, 49.4% and 42.4%, respectively, and fermentation rates by 63.3%, 132.4%, 49.4% and 42.4%, respectively. In sheep metabolism trials, DM digestibilities of rice straw treated with anhydrous and aqueous ammonia were increased 22% and 36%, respectively, and digestible DM intakes by 48% and 70%, respectively in sheep fed anhydrous and aqueous ammonia treated rice straw over untreated rice straw. Rumen ammonia and blood urea were considerably higher in sheep fed ammonia treated rice straw than sheep fed untreated rice straw. Daily gain of Holstein bulls was increased 20.8% and 29.9% and rice straw intakes were increased 28.4% and 44.3% in anhydrous and aqueous ammonia treated rice straw over untreated rice straw. Feed conversion was improved 9.5% and 10.3% and feed cost/gain was reduced 7.1% and 9.2% respectively in anhydrous and aqueous ammonia treated rice straw group as compared with untreated rice straw group.

Pharmaceutical Study on Ampicillin-polyvinylpyrrolidone Coprecipitate (Ampicillin-polyvinylpyrrolidone 공침물(共沈物)에 관한 약제학적(藥劑學的) 연구(硏究))

  • Kim, Johng-Kap;Eam, Jin-Soop
    • Journal of Pharmaceutical Investigation
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    • v.10 no.4
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    • pp.23-29
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    • 1980
  • Ampicillin-polyvinylpyrrolidone coprcipitates, 1 : 5 ratio w/w, were prepared by the solvent method to increase the solubility and dissolution rate of ampicillin anhydrous. It was found that the solubility and dissolution rate of the coprecipitate were higher than that of ampicillin anhydrous, mechanical mixture of ampicillin and polyvinylpyrrolidone in powder state. The intrinsic, dissolution rate, G, are $1.15{\times}10^{-4}\;mole\;cm^{-2}\;min^{-1}$ for the coprecipitate, $1.09{\times}10^{-5}\;mole\;cm^{-2}\;min^{-1}$ for ampicillin anhydrous, and the activation energy of the coprecipitate and ampicillin anhydrous are $9.091{\times}10^3cal/mole$ and $1.854{\times}10^3cal/mole$, respectively.

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The Effect of Compressing ER Electrode on the Electrorheological Properties of ER Fluids (ER 유체용 압축전극이 ER 유체의 전기유변학적 특성에 미치는 영향)

  • 안병길
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.11a
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    • pp.138-145
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    • 2001
  • For increasing the yield stress of ER fluids, the compressing ER electrode was developed and the compressing electrorheological (ER) behavior of anhydrous ER fluids in silicone oil of phosphorous ester cellulose powder was investigated. Under constant electric field, not only the current density but also the yield stress of anhydrous ER fluids were studied as varying the compressing length of compressing ER electrode. From the experimental results, the compressing of ER electrode had a large influence to the ER properties of anhydrous ER fluids. The current density was proportional to the compressing length of ER electrode under constant electric field and volume fraction also the compressing yield stress was proportional to the volume fraction of dispersed particles under constant electric field and compressing length. When the ER electrode was compressed with 150mm after charging the electric field, 4 kV, the yield stress of phosphoric ester cellulose ER fluids increased to thirteen times comparing with the yield stress measured at normal electrode.

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The Effect of Surfactant on the Electrorheological Properties of Phosphoric Ester Cellulose ER Fluids (인산 에스테르 셀룰로오스 ER 유체의 전기유변학적 특성에 대한 계면활성제의 영향)

  • 안병길;최웅수;권오관
    • Tribology and Lubricants
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    • v.15 no.3
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    • pp.240-247
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    • 1999
  • The electrorheological (ER) behavior of suspensions in silicone oil of phosphoric ester cellulose particles (average particle size : 18$\pm$1${\mu}{\textrm}{m}$) coated with octadecylamine ( $C_{18}$ $H_{37}$ N $H_2$) as surfactant was investigated at room temperature. For development of anhydrous ER suspension using at real application, it should be researched how can reduce deposition of ER particles in ER suspension. Anhydrous ER suspensions mixing with phosphoric ester cellulose particles coated with octadecylamine were measured. As increasing the coating concentration of octadecylamine, not only analysis of electrical properties such as dielectric constant, current density and electrical conductivity but also rheological properties of ER suspensions were studied. From the experimental results, coating concentration of surfactant had large influence to ER properties of anhydrous ER suspension. Current density, conductivity and electrorheological effect ($\tau$/$\tau$$_{0}$) of ER suspension were linearly reduced with increasing the coating concentration of octadecylamine. But ER suspensions dispersed the phosphoric ester cellulose particles coated with octadecylamine showed reducing deposition of ER particles and could be redispersed easily.

Electrorheological Properties of Phosphoric Ester Cellulose ER Fluids on the Elevated Temperature (온도 변화에 따른 인산 에스테르 셀룰로오스 ER 유체의 전기유변학적 특성)

  • 안병길;오경근;최웅수;권오관
    • Tribology and Lubricants
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    • v.15 no.1
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    • pp.8-16
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    • 1999
  • The electrorheological (ER) behavior of suspensions in silicone oil of phosphoric ester cellulose powder (average particle size : 18$\pm$1 ${\mu}{\textrm}{m}$) was investigated on the elevated temperature up to 10$0^{\circ}C$. For development of anhydrous ER fluids using at wide temperature range, it should be researched to how the effect of temperature on the ER activities. As a first step, the anhydrous ER suspensions mixing with the phosphoric ester cellulose particles which were made from the phosphoric ester reaction of cellulose were measured. As increasing the temperature, not only the analysis of electrical properties such as dielectric constant current density and electrical conductivity but also the rheological properties of ER fluids were studied. From the experimental results, the temperature had a large influence to the ER properties of anhydrous ER fluids. The current density, conductivity and elecoorheological effect ($\tau$$_{A}$$\tau$$_{0}$) of phosphoric ester cellulose ER fluids were proportional to the temperature with power law. And the shear stress of them was closely related with the square of dielectric constant mismatch parameter ($\beta$$^2$) under constant shear rate and electric field.d.

Temperature-Viscosity Characteristics of Hydrous and Anhydrous Electro-Rheological Fluids (함수계와 비수계 ER유체의 온도-점도 특성)

  • 이진우;장성철;염만오;김도태;박재범
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.451-456
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    • 2002
  • This paper describes the properties of Temperature-Viscosity characteristics of hydrous and anhydrous ER fluids containing starch and titanium particle in silicone oil. ER effects arise from electrostatic forces between the starch particles and titanium particles dispersed in the electrically insulating silicone oil induced when electric field is applied. ER fluids under electric field have been found to provide resonable estimates of ER fluid viscosity variation characteristics. Yield shear stress of the ER fluids were measured on the couette cell type rheometer as a function of electric fields. The outer cup is connected to positive electrode(+) and bob becomes ground(-). The electric field is applied by high voltage DC power supply. In this experiment shear rates were increased from 0 to 200/equation omitted/ in 2 minutes.

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