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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Industrial and engineering chemistry 20 (1981), S. 496-501 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Electrochimica Acta 26 (1981), S. 255-260 
    ISSN: 0013-4686
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-1912
    Keywords: Alpha adrenoceptor agonists ; Rat tail artery ; Nicardipine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Although alpha-2 adrenoceptor agonists rapidly induce arterial vasoconstriction in vivo, such responses have proven difficult to obtain in vitro. We have investigated the vasoconstrictor effects of various alpha-1 and alpha2 adrenoceptor agonists in the perfused/superfused caudal artery of the normotensive rat. Intrinsic activities were: methoxamine: 1, phenylephrine: 0.94, noradrenaline: 0.93, guanfacine: 0.88, clonidine: 0.47, UK 14,304 [5-bromo-6-(2imidazoline-2-ylamino)-quinoxaline tartrate: 0.10, azepexole: 0. Antagonism by the selective alpha-1 agent, prazosin of the vasoconstrictor responses provoked by methoxamine, guanfacine or clonidine, showed a high affinity with -log K B values in the range of 8.5 to 9.4. There were no significant differences between the K B values obtained with the three agonists. Antagonism by the selective alpha-2 antagonist, yohimbine showed a low affinity with K B values between 6.7 to 7.6 for the three agonists. The calcium entry blocker, nicardipine, antagonized responses to clonidine at nanomolar concentrations and those to phenylephrine at micromolar concentrations. We conclude that vasoconstrictor responses in this isolated tail artery preparation are primarily mediated via an alpha adrenoceptor which can be classified, on the basis of the results with specific antagonists, as being of the alpha-1 type. The results obtained with nicardipine suggest that the population of alpha adrenoceptors is not, however, homogeneous.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 117 (1986), S. 159-165 
    ISSN: 1434-4475
    Keywords: Corrosion ; Thiophene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wurde die Korrosion von Eisen in 2M HNO3 mittels Messungen der elektrochemischen Polarisation und des Gewichtsverlustes untersucht. Dabei wurde der Einfluß einiger Thiophenderivate überprüft. Die Ergebnisse zeigen, daß die Inhibitoren, die den kathodischen und den anodischen Prozeß beeinflussen, an der Metalloberfläche in molekularer Form adsorbiert werden. Dabei wird der Reaktionsmechanismus der Reaktion zwischen Eisen und Salpetersäure nicht geändert, es wird jedoch die Geschwindigkeit herabgesetzt. Dieser Effekt ist mit den Dipolmomenten korrelierbar. Die Gewichtsverlustmessungen ergaben übereinstimmende Resultate.
    Notes: Abstract Corrosion of iron in 2MHNO3 has been studied by the electrochemical polarization and weight loss measurements. The effect of some thiophene derivatives has been investigated. The results show that the inhibitors under consideration, influencing both the cathodic and anodic process, are adsorbed on the metal surface in molecular form. They do not change the mechanism of the reaction between iron and nitric acid, but decrease its rate. This effect is controlled by the values of their dipole moments. The weight loss technique also gave the same order of inhibition efficiency of the tested inhibitors.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 126 (1995), S. 1217-1223 
    ISSN: 1434-4475
    Keywords: 2-Methyl-3-acetylquinoxaline-1,4-dioxide ; Cinnamoylquinoxaline 1,4-dioxide ; Phenazine 5,10-dioxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Mehrere Phenazin-5,10-dioxide (7a–d) wurden durch Reaktion von 2-Methyl-3-acetylchinoxalin-1,4-dioxid (2) mit verschiedenen aromatischen Aldehyden oder durch direkte Cyclisierung der Chinoxalinderivate3 in basischem Milieuhergestellt. Zusätzlich wurden die Phenazinderivate8 und9–12 in einer Eintopfreaktion von substituierteno-Nitroanilinen mit verschiedenen Hydroxyverbindungen in Gegenwart von Natriumhypochloritlösung synthetisiert.
    Notes: Summary Several phenazine 5,10-dioxides (7a–d) were prepared by the reaction of 2-methyl-3-acetylquinoxaline 1,4-dioxide (2) with different aromatic aldehydes or by direct cyclization of the quinoxaline cinnamoyl derivatives3 in basic medium. In addition, the phenazine derivatives8 and9–12 were synthesized by a one-pot reaction of substitutedo-nitroanilines with different hydroxy compounds in the presence of sodium hypochlorite solution.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 126 (1995), S. 369-376 
    ISSN: 1434-4475
    Keywords: Acid corrosion ; Inhibition ; Iron ; Oxygen and nitrogen containing compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die von Chinin, Ephedrin, Brucin, Chinchonin, Codein und Harmalin ausgeübte Korrosionshemmung bei der Auflösung von Eisen in 2M Schwefelsäure wurde mittels elektrochemischer Methoden untersucht. Polarisationskurven zeigen, daß die erwähnten Verbindungen als Inhibitoren gemischten Typs fungieren, d. h. sowohl die kathodische als auch die anodische Kurve wurde beeinflußt. Der beobachtete Effekt folgt derTemkinschen Adsorptionsisotherme. Die Auswirkung von Strukturänderungen auf die Effizienz der Hemmung und einige thermodynamische Funktionen werden diskutiert. Die Korrosionstrate von Eisen steigt sowohl in Gegenwart als auch in Abwesenheit der Inhibitoren im Bereich von 30–50°C mit steigender Temperatur.
    Notes: Summary Corrosion inhibition by quinine, ephedrine, brucine, cinchonine, codeine, and harmaline with respect to the dissolution of iron in 2M sulphuric acid was measured using electrochemical methods. Polarization curves indicated that these compounds act as mixed-type inhibitors,i.e. both the cathodic and anodic curves are affected. The observed effect follows theTemkin adsorption isotherm. The effect of the different structural features of these compounds on their inhibition efficiency has been studied. Results indicate that the rate of corrosion of iron increases with increasing temperature over the range 30–50 °C both in the absence and in the presence of inhibitors. Some thermodynamic functions were also computed and are discussed.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 118 (1987), S. 709-716 
    ISSN: 1434-4475
    Keywords: Corrosion ; Inhibitor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wurden fünf Derivate von Phenylthiosemicarbazid hergestellt und als Inhibitoren für die Korrosion von Aluminium in 2M NaOH eingesetzt. Die Substanzen ergaben 98.5 bis 75% Schutz für Aluminium in NaOH. Dabei war 1-(Methoxybenzoyl)-4-phenyl-3-thiosemicarbazid der effizienteste Inhibitor. Thermometrische und Gewichtsverlustmethoden zeigten, daß die Inhibition prinzipiell von der Adsorption dieser Verbindungen auf der Metalloberfläche gesteuert wird, wobei die Adsorbierbarkeit der Inhibitoren von der Basizität der teilnehmenden Sauerstoff- und Schwefelfunktionen abhängt.
    Notes: Abstract Five derivatives of phenylthiosemicarbazide have been prepared and treated as inhibitors for the corrosion of aluminium in 2M sodium hydroxide. All the five substances afford 98.5 to 75% protection to aluminium in sodium hydroxide. 1(-Methoxybenzoyl)-4-phenyl-3-thiosemicarbazide being the most efficient inhibitor. Thermometric and weight loss methods indicate that the inhibition is principally governed by the adsorption of these compounds on the surface of the aluminium metal and the adsorbability of inhibitors is dependent on the basicity of the oxygen and sulphur sites involved.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Journal of radioanalytical and nuclear chemistry 118 (1987), S. 45-58 
    ISSN: 1588-2780
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Electrodeposition of tellurium from metal salt solutions in the presence of phthalic acid and inorganic substances at controlled pH has been investigated. The current density ranged from 0.28 to 11.34 mA cm−2. The percentage cathodic current efficiency was relatively low and increased with increasing concentration of tellurion ions in the bath. The purity of the deposited metal was better than 99%. X-ray diffraction analysis shows that the deposit belongs to the hexagonal structure.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 26 (1995), S. 357-361 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The effect of some hydrazone oxime derivatives on the corrosion of iron in 2M HCl have been studied by polarization and weight-loss techniques. It was found that the compounds under consideration are adsorbed on the iron surface according toe the Temkin isotherm. The Tafel slope is approximately constant independent of the concentration of the inhibitor. The results of polarization indicate that all compounds tested were of a mixed type, but the cathodic is more preferenially polarized.The inhibition efficiency was found to follow the order:I〉III〉IV〉VI〉II.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 26 (1995), S. 488-492 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The electrodeposition of palladium from electrolytes containing palladium chloride along with potassium-dihydrogen phosphate, sodium fluoride or oxalic acid was studied under a variety of condition. The conditions used were: 1.0 M palladium chloride, 0.15 M potassium dihydrogen phosphate, pH 1.5 at 298 K and current density 0.85 mA cm-2/ The current efficiency was calculated and the crystal structure confirmed by X-ray analysis. Spectrophotomteric and chemical analysis reveals that the purity of the metal is better than 99%. Palladium electrode can function satisfactorily as indicator electrode for hydrogen ions in acid-base titrations. Titration of acids with sodium hydroxide and of salts of weak acids with hydrochloric acid showed that palladium can indicate very accurately the end point. The end point coincide to great extent with the visual values with an error not more than ± 2%.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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