9 results on '"Peng, I.-H."'
Search Results
2. Vapor−Liquid Equilibria of Acetone, Diisopropyl Ether, Ethanol, and Methyl Ethyl Ketone with Hydrocarbon Mixtures at 101.3 kPa
- Author
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Peng, I.-H. and Tu, C.-H.
- Abstract
Isobaric vapor−liquid equilibria (VLE) data were measured at 101.3 kPa on four oxygenates (acetone, diisopropyl ether, ethanol, and methyl ethyl ketone) separately with hydrocarbon mixtures. Acetone, ethanol, and methyl ethyl ketone were mixed with a five-component hydrocarbon mixture and diisopropyl ether was mixed with a four-component hydrocarbon mixture. Calculations of nonideality of the vapor phase were made with the Soave−Redlich−Kwong equation of state. The vaporization equilibrium ratio of oxygenate in the hydrocarbon mixture was derived. Analysis of the experimental VLE data exhibits a minimum boiling temperature for the systems containing acetone, ethanol, and methyl ethyl ketone. The experimental data have been correlated with the mole fraction of oxygenate using the Redlich−Kister-type and Wisniak−Tamir equations.
- Published
- 2004
3. Densities and Viscosities of Acetone, Diisopropyl Ether, Ethanol, and Methyl Ethyl Ketone with a Five-Component Hydrocarbon Mixture from 288.15 K to 308.15 K
- Author
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Peng, I.-H. and Tu, C.-H.
- Abstract
Densities and viscosities were measured for the systems of four oxygenates (acetone, diisopropyl ether, ethanol, and methyl ethyl ketone) separately with a five-component hydrocarbon mixture at three temperatures (288.15, 298.15, and 308.15) K and atmospheric pressure. The five-component hydrocarbon mixture contains 25 mol % hexane, 10 mol % heptane, 35 mol % 2,2,4-trimethylpentane, 20 mol % toluene, and 10 mol % p-xylene. Densities were determined using a vibrating-tube densimeter. Viscosities were measured with an automatic Ubbelohde capillary viscometer. Excess molar volumes VE and deviations in viscosity Δη for the mixtures were derived from experimental data, and the computed results were fitted to a Redlich−Kister-type equation.
- Published
- 2002
- Full Text
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4. Density and Viscosity of Mixtures of Alkoxypropanols with Ethanol at T = (298.15, 308.15, and 318.15) K
- Author
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Ku, S.-C., Peng, I.-H., and Tu, C.-H.
- Abstract
Densities and viscosities were measured for the binary mixtures formed by 1-methoxy-2-propanol, 1-propoxy-2-propanol, 1-butoxy-2-propanol, dipropylene glycol methyl ether, dipropylene glycol propyl ether, and dipropylene glycol butyl ether with ethanol at T = (298.15, 308.15, and 318.15) K and atmospheric pressure over the whole concentration range. Densities were determined using a vibrating-tube densimeter. Viscosities were measured with an automatic Ubbelohde capillary viscometer. The estimated uncertainties are less than ±1 × 10-4 g·cm-3 for density and ±0.6% for viscosity. Excess volumes VE and deviations in viscosity Δη for the mixtures were derived from the experimental data, and the computed results were fitted to the Redlich−Kister equation. Furthermore, McAllister's multibody-interaction model is used to correlate the binary kinematic viscosities.
- Published
- 2001
5. Excess Volumes and Viscosities of Binary Mixtures of Aliphatic Alcohols (C<INF>1</INF>−C<INF>4</INF>) with Nitromethane
- Author
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Tu, C.-H., Lee, S.-L., and Peng, I.-H.
- Abstract
Densities and viscosities were measured for the binary mixtures of methanol, ethanol, propan-1-ol, propan-2-ol, butan-2-ol, and 2-methyl-propan-2-ol with nitromethane at temperatures from 293.15 K to 313.15 K and atmospheric pressure. Densities were determined using a vibrating-tube densimeter. Viscosities were measured with an automatic Ubbelohde capillary viscometer. The estimated uncertainties are less than ±0.0001 g·cm-3 for density and ±0.7% for viscosity. Excess volumes and viscosity deviations as a function of mole fraction average were derived, and the computed results were fitted to the Redlich−Kister equation. Furthermore, McAllister's three-body-interaction model is used to correlate the binary kinematic viscosities.
- Published
- 2001
6. An engineering model to characterize oxygen transfer rates for liposome encapsulated hemoglobin (LEH).
- Author
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Chung TW and Peng IH
- Subjects
- Biomechanical Phenomena, Cell Respiration, Engineering, Humans, Liposomes, Models, Theoretical, Hemoglobins metabolism, Oxygen metabolism
- Abstract
An engineering model was designed to evaluate oxygen transfer rates for LEH and other oxygen carriers under wall shear rates from 150 sec-1 to 450 sec-1. The results showed that increasing the shear rates (or flow rates) of oxygen carriers flowed inside of hollow fiber tubes would increase oxygen transfer rates to outside media. The values of overall oxygen transfer rate coefficients for LEH, based on 1 g/dl of hemoglobin contents, were about 2 to 2.5 times higher than those values for human blood at all of tested shear rates (e.g., 5.1 x 10(-5) cm/sec and 2.1 x 10(-5) cm/sec for LEH and blood at wall shear rates of 450 sec-1, respectively). Moreover, the results of oxygen transfer efficiency for LEH calculated by this model were consistent with the similar results reported by Usuba et al.[3] obtained by animal study. With an engineering model, we possibly estimate the effects of other factors such as viscosity on the oxygen transfer rates for LEH in microcirculation.
- Published
- 1998
- Full Text
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7. Antihypertensive and Hypolipidemic Effects of DC-015, a Novel, Potent and Specific alpha(1)-Adrenoceptor Antagonist: Comparison with Prazosin in Spontaneously Hypertensive Rats.
- Author
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Peng IH, Sheu JR, Chern JW, Lee YM, and Yen MH
- Abstract
The hypotensive effect of DC-015, a newly synthesized quinazoline derivative, was investigated and compared with prazosin in spontaneously hypertensive rats (SHR). Intravenous administration of DC-015 and prazosin (both at 0.01, 0.05 and 0.1 mg/kg) induced a dose-dependent reduction of mean arterial pressure (MAP) which reached a maximal effect at 5 min after injection and persisted over 2 h in SHR. Furthermore, at higher doses DC-015 (0.1 mg/kg i.v. and 2.0 mg/kg orally, respectively) did not cause any significant changes in heart rate (HR); whereas the same doses of prazosin (0.1 mg/kg i.v. and 2.0 mg/kg orally, respectively) produced a decrease in HR which seems to parallel the time course of the hypotensive response in SHR. DC-015 and prazosin attenuated pressor responses to phenylephrine (10 &mgr;g/kg) but failed to inhibit the pressor effects of angiotensin II (0.5 &mgr;g/kg) even at the maximal hypotensive dose (0.1 mg/kg). This observation indicates that DC-015 appears to exert its hypotensive effect through alpha(1)-adrenoceptor blockade. On the other hand, in SHR fed a high-fat-high-cholesterol (HF-HC) diet, oral administration of DC-015 and prazosin (both at 1.0 mg/kg, twice a day) for 4 weeks caused significant reductions in total plasma cholesterol (CE), low-density lipoprotein (LDL)-cholesterol and total plasma triglyceride (TG). DC-015 therapy also increased high-density lipoprotein (HLD)-cholesterol levels, thus the ratio of total plasma cholesterol to HDL-CE was improved. In contrast, prazosin did not significantly increase the HDL-CE level in this study. It is concluded that DC-015 decreased MAP, plasma CE, LDL-CE, plasma TG and increased HDL-CE levels. DC-015 may have therapeutic potential as a potent antihypertensive drug via the alpha(1)-adrenoceptor antagonist. Concurrently, DC-015 may thus hold some advantage for the reduction of two of the major risk factors, hypertension and hyperlipidemia, for cardiovascular diseases. Copyright 1996 S. Karger AG, Basel
- Published
- 1996
- Full Text
- View/download PDF
8. Effects of DC-015, a novel potent and selective alpha 1-adrenoceptor antagonist on plasma lipid and vascular reactivity in hyperlipidaemic rats.
- Author
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Sheu JR, Peng IH, Lee YM, and Yen MH
- Subjects
- Animals, Aorta drug effects, Dose-Response Relationship, Drug, Hyperlipidemias blood, In Vitro Techniques, Male, Muscle Relaxation, Muscle, Smooth, Vascular metabolism, Prazosin pharmacology, Rats, Rats, Inbred SHR, Rats, Inbred WKY, Adrenergic alpha-1 Receptor Antagonists, Adrenergic alpha-Antagonists pharmacology, Blood Pressure drug effects, Hyperlipidemias physiopathology, Lipids blood, Lipoproteins blood, Muscle, Smooth, Vascular drug effects, Quinazolines pharmacology
- Abstract
1. The effects of DC-015, a newly synthesized quinazoline derivative, on plasma lipids, lipoprotein levels and vascular reactivity were investigated in Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). 2. The hypotensive effect of DC-015 was compared with prazosin in SHR. Intravenous administration of DC-015 and prazosin (both at 0.01, 0.05 and 0.1 mg/kg) induced dose-dependent reductions in mean arterial pressure (MAP) which reached a maximal effect 5 min after injection and persisted over 2 h in SHR. DC-015 decreased MAP with equal efficiency compared with prazosin. 3. The plasma levels of total cholesterol (CE), low-density lipoprotein (LDL)-CE and total triglyceride (TG) were markedly increased and the levels of high-density lipoprotein (HDL)-CE were markedly decreased in both high fat-high cholesterol (HF-HC) diet fed WKY and SHR. 4. In HF-HC diet fed WKY and SHR, the total plasma CE, LDL-CE and total plasma TG were significantly reduced after oral administration of DC-015 (1 mg/kg, twice a day) for 4 weeks. Furthermore, DC-015 therapy was associated with increased HDL-CE levels and thus the ratio of total CE to HDL-CE was improved. The antihyperlipidaemic effect of prazosin was less than that of DC-015. 5. Significantly attenuated median effective concentration (EC50) values and augmented maximal responses for phenylephrine-induced contraction of aortic rings were observed in HF-HC diet fed WKY and SHR. Endothelium-dependent relaxation to acetylcholine was impaired while endothelium-independent relaxation to nitroglycerin was well preserved. 6. Oral administration of DC-015 (1 mg/kg, twice a day) for 4 weeks significantly augmented EC50 values and attenuated maximal responses for phenylephrine-induced contraction of aortic rings in HF-HC diet fed WKY and SHR. Prazosin (1 mg/kg, twice a day) showed a lesser extent of efficiency than DC-015 at normalization of vasorelaxation in HF-HC diet fed WKY and SHR. 7. It is concluded that DC-015, a potent antihypertensive agent, may have additional advantage in also reducing hyperlipidaemia.
- Published
- 1996
- Full Text
- View/download PDF
9. Pharmacological activity of DC-015, a novel potent and selective alpha 1-adrenoceptor antagonist.
- Author
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Yen MH, Sheu JR, Peng IH, Lee YM, and Chern JW
- Subjects
- Adrenergic alpha-1 Receptor Antagonists, Adrenergic alpha-Antagonists administration & dosage, Adrenergic alpha-Antagonists therapeutic use, Animals, Antihypertensive Agents administration & dosage, Antihypertensive Agents pharmacology, Antihypertensive Agents therapeutic use, Aorta, Thoracic drug effects, Aorta, Thoracic metabolism, Binding, Competitive, Cyclic AMP metabolism, Disease Models, Animal, Dose-Response Relationship, Drug, Female, Injections, Intravenous, Male, Muscle Contraction drug effects, Muscle, Smooth, Vascular metabolism, Phenylephrine pharmacology, Phosphatidylinositols metabolism, Prazosin administration & dosage, Prazosin pharmacology, Prazosin therapeutic use, Quinazolines administration & dosage, Quinazolines therapeutic use, Rats, Rats, Inbred SHR, Rats, Sprague-Dawley, Serotonin Antagonists metabolism, Serotonin Antagonists pharmacology, Serotonin Antagonists therapeutic use, Vasoconstriction drug effects, Adrenergic alpha-Antagonists pharmacology, Blood Pressure drug effects, Hypertension drug therapy, Muscle, Smooth, Vascular drug effects, Quinazolines pharmacology
- Abstract
The pharmacological activity of 3-((4-(2-methoxyphenyl)piperazin-1-yl)methyl)-2,3-dihydroimidaz o(1,2 -c)quinazolin-5(6H)-one (DC-015), a newly synthesized quinazoline derivative, was determined in rat isolated thoracic aorta and pressor responses were determined in spontaneously hypertensive rats (SHR). Experimental results indicated that DC-015 is an alpha 1-adrenoceptor-blocking agent in rat thoracic aorta as revealed by its competitive antagonism of phenylephrine-induced vasocontraction (pA2 = 10.54 +/- 0.55). These effects still persisted in denuded aorta. It was as potent as prazosin (pA2 = 10.04 +/- 0.63). At higher concentration (1.0 microM), DC-015 also expressed 5-hydroxytryptamine (5-HT) receptor competitive antagonism, but this 5-HT blocking effect was not found in the prazosin-administration group. [3H]Inositol monophosphate formation stimulated by phenylephrine (30 microM) in rat thoracic aorta was diminished by DC-015 (3 and 10 nM) and prazosin (10nM); whereas the cAMP content of rat thoracic aorta was not altered by DC-015 and prazosin. Furthermore, intravenous administration of DC-015 and prazosin (both at 0.01, 0.05 and 0.1 mg/kg-1) induced a dose-dependent reduction of mean arterial pressure which reached a maximal effect at 5 mm after injection and persisted over 2 h in SHR. A higher dose of DC-015 (0.1 mg/kg-1, i.v.) did not cause any significant changes in heart rate, whereas, the same dose of prazosin (0.1 mg/kg-1, i.v.) produced a decrease which seems to parallel the time course of the hypotensive response. We can conclude that the DC-015 is a potent, highly selective alpha 1-adrenoceptor antagonist in vascular smooth muscle.
- Published
- 1996
- Full Text
- View/download PDF
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