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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 6265-6269 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: This work describes some investigations on the atomic and ionic beams generated by a CdS target under excimer laser irradiation at 308 nm, and on factors influencing the quality of the films obtained. The angular distribution of particles emitted in a vacuum was found to be highly directional, concentrated around a direction normal to the target surface. The angular emission pattern depends on laser fluence. The method used for studying the emission pattern helps in positioning substrates for optimum film quality and uniformity. Measurements of the energy of the emitted particles yielded high values (several tens of eV) for both ionized and neutral particles, suggesting a nonthermal mechanism. Some possible models are discussed. Finally, considerable improvement in both film uniformity and homogeneity was obtained through the use of a laser-triggered plasma discharge in the source region. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Archives of Biochemistry and Biophysics 161 (1974), S. 441-447 
    ISSN: 0003-9861
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1436-5073
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung 1,3-Bis(2-pyridyl)-methylenaminothioharnstoff (PMAT) und 1,3-Bis-(2-pyridyl)-methylenaminoguanidin (PMAG) wurden auf ihre Eignung als selektive spektrophotometrische Reagenzien für Eisen geprüft. PMAT gibt in saurem Medium mit Fe(II) eine Rotfärbung mit dem Absorptionsmaximum bei 590 nm und der molaren Absorptivität 7,2·103l·mol−1·cm−1. PMAG gibt ebenfalls eine Rotfärbung. Die Reaktion bei pH 4,2 ist sehr empfindlich (ε=2,09·104l· mol−1·cmr−1 bei 570 nm). Die beiden Reagenzien wurden zur Bestimmung des Eisens in Erzen und Legierungen verwendet.
    Notes: Summary 1,3-Bis[(2-pyridyl)methyleneamino]thiourea (PMAT) and 1,3-bis-[(2-pyridyl) methyleneamino]guanidine (PMAG) have been examined to evaluate their usefulness as selective spectrophotometric reagents for iron. PMAT forms a red colour with iron(II) in acid medium, with maximum absorption at 590 nm, the molar absorptivity being 7.2×103l·mole−1·cm−1. PMAG also gives a red colour and the reaction at pH 4.2 is very sensitive (ε=2.09×104l·mole−1·cm si−1 at 570 nm). The reagents have been applied to the determination of iron in ore and alloys.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1436-5073
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Synthese, die Eigenschaften und die spektrophotometrische Verwendung von 1,3-[(2-Pyridyl)methylenamino]-Harnstoff (PMAU) wurden beschrieben und seine Eignung als Reagens für Calcium wurde geprüft. PMAU reagiert mit Calcium in alkalischem Medium unter Bildung eines gelben Komplexes (λmax=430 nm, ε=1,0×104l·mol−1·cm−1 im Verhältnis l∶ 1. Ein spektrophotometrisches Verfahren für die Calciumbestimmung wurde vorgeschlagen. Durch Zufügen von Maskierungsmitteln können Störungen weitgehend vermieden werden. Das Verfahren wurde für die Bestimmung von Ca in Wässern, Milch, Tabak und Drogen verwendet und die Ergebnisse mit jenen verglichen, die mit GIyoxal-bis-(2-hydroxyanil) und Murexid erhalten wurden.
    Notes: Summary The synthesis, characteristics and spectrophotometric uses of 1,3-bis[(2-pyridyl)methyleneamino]urea (PMAU) are described, and its usefulness as a reagent for calcium has been examined. This compound reacts with calcium in alkaline medium to form a yellow complex (λmax=430 nm, ε=1.6×104l·mole−1·cm−1 with 1∶1 stoichiometry. A valuable spectrophotometric method is proposed for the determination of calcium and the interferences are minimized by addition of masking agents. The procedure has been used for the determination of calcium in waters, milk, tobacco and drugs and the results are compared with those obtained with glyoxal bis (2-hydroxyanil) and murexide.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1436-5073
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung 1,3-Bis[di(2-pyridyl)methylenamino]harnstoff wurde auf seine Eignung als selektives spektrophotometrisches Reagens für Kupfer geprüft. Es gibt in saurer Lösung mit Kupfer eine gelbe Komplexverbindung mit einem Absorptionsmaximum bei 400 nm und einer molaren Absorbanz von 1,49×10−41·mol−1·cm−1. Kupfer läßt sich damit in Gegenwart vielerlei anderer Ionen quantitativ bestimmen. Das Reagens wurde für die Kupferbestimmung in Getränken, Futtermitteln, Drogen und Legierungen verwendet.
    Notes: Summary 1,3-Bis[di(2-pyridyl)methyleneamino]urea has been examined as a selective Spectrophotometric reagent for copper. It gives a yellow complex with copper in acid medium (pH 1), with an absorption maximum at 400 nm, and molar absorptivity 1.49×1041·mole−1· cm−1. Copper can be quantitatively determined with it in the presence of a large number of ions. The reagent has been applied to the determination of copper in beverages, feeding-stuffs, drugs and alloys.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' journal of analytical chemistry 361 (1998), S. 509-511 
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A flow injection (FI) chemiluminescence method for the determination of Cr(III) in blood serum, urine and hair samples is reported. It is based on the chromium-catalyzed light emission from the luminol oxidation by hydrogen peroxide. The apparatus consists of an FI system with a flow cell formed by a coiled transparent tube suitable for chemiluminescence detection. The specificity of the method is achieved in presence of EDTA. The detection limit under optimum conditions is 0.01 μg L–1 of Cr(III). Precision and accuracy were evaluated by determining Cr(III) concentrations in urine standards from the National Institute of Standard and Technology (NIST).
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Pyruvic acid condenses with Girard-P reagent to form a hydrazone derivative (PAHPy). From the present polarographic investigations, it was deduced that the two d.p. waves (Ep1 = −0.76 V and shoulder-like peak Ep2 = −1.06 V at pH = 4.5) probably correspond to two kinds of species in equilibrium: the cyclized lactonic form and the open form of the hydrazone, respectively. The first wave is more appropiate for quantification owing to its higher sensitivity, and in this way pyruvic acid was determined in the concentration range 2.5 × 10−5 to 0.035 mol/l at pH 2.4. Carbohydrates, alcohols and carboxylic acids except α-ketoacids show tolerance limits of a least 10 times the amount of pyruvic acid (mg). The method was satisfactorily applied to evaluate the pyruvate content of milk.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1573-7284
    Keywords: Population-based study ; Survival ; Upper aerodigestive cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of this work was to make a study of the whole population of a central Italian region, the Umbria region – cancer survival rates for the upper aerodigestive tract, which includes cancers of the head and neck (tongue, oral cavity, pharynx), oesophagus and larynx. In Italy cancer survival rates do not cover entire regions but single municipalities or provinces. Cases of incidence were derived from an ‘ad hoc’ survey carried out during the period 1978–1982. Starting from the nominative data, we studied up to 15 years 245 head and neck, 87 oesophagus and 321 larynx cases of cancer in males. Data for female cases were not considered because of the small number. Cancer cases were followed up mainly by verification at the Registry Office of several municipalities, the Regional Death Registry and the list of persons under the Regional Health Service. Observed survival rates for head and neck cancer were 0.63, 0.29, 0.17 and 0.12 at 1, 5, 10 and 15 years of follow-up respectively; rates for cancers of the oesophagus and larynx were 0.30, 0.08, 0.06, 0.03 and 0.79, 0.54, 0.41, 0.30 respectively. Relative survival rates were 0.65, 0.34, 0.24, 0.23 for cancer of the head and neck, 0.31, 0.10, 0.09, 0.08 for cancer of the oesophagus, and 0.81, 0.63, 0.59, 0.56 for cancer of the larynx, at 1, 5, 10 and 15 years of follow-up. The worst survival rates were observed for oesophagus and hypopharynx. Overall survival values for Umbrian patients were relatively good, being higher than survival data reported for a similar period by Italian Cancer Registries. They were also strikingly similar to survival rates for England and Scotland.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1573-2932
    Keywords: analysis of river sediments ; cluster analysis ; correlation analysis ; factor analysis ; Guadaira River ; metal partitioning ; water-sediment interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract A physical-chemical characterisation of the sedimentsof the Guadaira River in Southwest Spain has beencarried out, determining twenty-three parameters persample. Non-treated urban sewage and industrialwastewaters from olive oil and table olives affectthis river. The factor analysis of the data showshigh organic matter contents with metallicpollution. Consequently, points downstreamstand out because of very high organic and metallicpollution (Zn, Pb, Cr, Cu and Cd, in order ofabundance, showing concentrations in sediments rangingfrom 50–7500 times those of waters). Heavy metals partitioning studies can be a goodapproach to show the real activity of these metals in theaquatic environment. We applied Tessier's analytical sequential extraction scheme to sediments.Sediments would be in general mildly hazardous because wefound low levels of easily interchangeable metals in the first fraction. Nevertheless, that is not thecase in the river's last stretch, precisely wheresediments are most abundant, the heavy metal levelslargest and dredgings are made periodically. Here,their disposal is of concern; since the actual use ofthese sediments as organic amendment for agriculturalsoils is unacceptable.Interaction between waters and sediments in theriverbed by means of correlation, factor and clusteranalysis on waters and sediments data, wasinvestigated. With this approach we concluded that inthe final stretch there is a problem of contaminationof both, sediments and waters. However, in the middlecourse only sediments are actually polluted. Thiscorresponds to the previous research, when thesituation of waters in this zone was even worse.
    Type of Medium: Electronic Resource
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