Investigation of the Morphological and Mechanical Properties of Polyethylene Terephthalate (PET)/Ethylene Propylene Diene Rubber (EPDM) Blends in the Presence of Multi-Walled Carbon Nanotubes

In this study the blends of polyethylene terephthalate (PET)/ethylene propylene diene rubber (EPDM) in the presence of multi-walled carbon nanotubes (MWCNT) (1 and 3?wt %) were prepared by melt compounding in an internal mixer. Mechanical and morphological properties of the nanocomposites were investigated. The thermal behaviors of the PET/EPDM nanocomposites were also investigated, by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results of the mechanical tests showed that the tensile strength, elastic modulus and the hardness of the blends were increased with increasing CNT, while the impact strength and elongation at break decreased. The DSC and TGA results showed an increase of melting temperature (T_m) and degradation temperature of the nanocomposites with the addition of the carbon nanotubes, because the carbon nanotubes serve both as nucleating agents to increase T_m and prevent the composite from degradation to increase the thermal stability. The microstructure of the composites was evaluated through field emission scanning electron microscopy (FESEM) and the results showed a good distribution of the MWCNT within the polymer blend.     

Surface Analysis of Inhibitor Film Formed by 4-Amino-N-(1,3-thiazol-2-yl) Benzene Sulfonamide on Carbon Steel Surface in Acidic Media

Inhibitive properties of the antibacterial sulfa drug sulfathiazole—IUPAC name being 4-amino-N-(1,3-thiazol-2-yl) benzene sulfonamide—on the corrosion of carbon steel in 1.0 M HCl solution were investigated using weight loss measurements, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Sulfathiazole is a good adsorption inhibitor, and the inhibition efficiency increases with increasing concentration. Adsorption is spontaneous and is best described by Temkin isotherm. XPS analysis showed, at this stage, that the main product of corrosion is a nonstoichiometric Fe³⁺ oxide/oxyhydroxide consisting of a mixture of Fe₂O₃, α, and γ-FeO(OH) and/or Fe(OH)₃, where α, γ-FeO(OH) is the main phase.     

Infrared Observation of the Effects of Aqueous Oxidizing Agents on the Functional Groups on Carbon Surfaces

FTIR photothermal beam deflection spectroscopy (PBDS) was used to record infrared spectra of medium-temperature carbons before and after they had been subjected to treatments with aqueous HNO₃ or H₂O₂ solution. Changes in the functional groups present on the carbon surfaces can be clearly observed.     

1H and C-13 Nuclear Magnetic Resonance of Tiaprofenic Acid

¹H-NMR spectrum of tiaprofenic acid in CDCI3 was obtained and proton chemical shifts from tetramethylsilane were assigned to each proton and set of equivalent protons of the molecule. The hydroxy proton of the carboxylic acid group was confirmed by deuterium exchange. The natural abundance C-13 nuclear magnetic resonance spectrum of the compound in CDCI3 was recorded using Fourier transorm technique. The chemical shifts of carbon resonances have been assigned on the basis of the chemical shift additivity theory and the signal multiplicity observed in the single frequency off-resonance decoupled (SFORD) spectrum. Also comparison with carbon chemical shifts of model compounds were useful.     

A Dual 13C and 15N Long Term Labelling Technique to Investigate Uptake and Translocation of C and N in Beech (Fagus sylvatica L.)

Abstract

A continuous dual ¹³CO₂ and ¹⁵NH₄ ¹⁵NO₃ labelling experimental set-up is presented that was used to investigate the C and N uptake and allocation within 3-year old beech (Fagus sylvatica L.) during one growing season. The C and N allocation pattern was determined after six, twelve and eighteen weeks of growth. The carbon uptake was distinctly different in the three phases examined: The first six weeks after budbreak were dedicated to leaf growth with a R/S (root to shoot) ratio of 0.14 for the new carbon. The second growth phase showed a balanced R/S ratio of C allocation and after week 13, the root compartment was the main carbon sink (R/S = 6.97).

Nitrogen allocation was more basipetal as compared to carbon. In the second growth phase, R/S of N_new was 5.57 but fell to 3.54 for the third growth phase probably due to formation of reserves in buds and stem.     

Nuklearpharmaka — Ihre Entwicklung,Präparation und Anwendungsmöglichkeiten

Radioaktiv markierte Präparate haben in denletzten Jahren in schnell zunehmendem Maße Eingang in die klinische Medizin gefunden. Sie sind beieiner Reihe von Indikationen schon jetzt außerordentlich wertvolle Hilfsmittel bei der Diagnose, besonders bei der Prüfung von Organfunktionen.     

Radioaktive und stabile Isotope bei der Lösung pflanzenphysiologischer Probleme

Es werden neuere Ergebnisse von Untersuchungen zur Biosynthese einiger Alkaloide und zum Stoffwechsel von Herbiziden mitgeteilt und diskutiert, die unter Verwendung von ¹⁴C, ³H und ¹⁵N durchgeführt wurden.     

Methodik und Ergebnisse von Tracerexperimenten über katalytische Reaktionen von Kohlenwasserstoffen

Tracermethoden können wichtige Beiträge zur Aufklärung katalytischer Kohlenwasserstoffreaktionen liefern. In dieser Arbeit werden einige Ergebnisse mehrjähriger Untersuchungen mit ¹⁴C-markierten Verbindungen zusammenfassend dargestellt. Es wird speziell auf Benzenbildungsreaktionen bei der Leichtbenzin-Reformierung und auf Reaktionsmechanismen bei der Isomerísierung von C₈-Aromaten eingegangen.     

Die Anwendung der Methode der zeitlich korrelierten assoziierten Teilchen (MEZKAT)

The TCAPM was developed to absolute and precise fission cross section measurement for neutron energies from 2 MeV up to 19 MeV. Experimental results of absolute fission cross section measurements on ²³³U, ²³⁵U, ²³⁸U, -²³⁷Np, ²³⁹Pu and ²¹²Pu are given. Furthermore the TCAPM is suitable for the application of inelastic scattering of neutrons by the analysis of element contents.