In the present study, the characteric-structure relationship of epoxidized soybean oils (ESO) with various degrees of epoxidation
has been investigated. FTIR analysis was used to identify the relative extent of epoxidation of the samples during the epoxidation
reaction. The viscosities of ESO were much higher than that of the raw oil, viscosity increased with degree of epoxidation.
The viscous-flow activation energy of ESO was determined to be higher than that of the raw oil (20.72 to 77.93% higher). Thermogravimetry
analysis (TG) of ESO was used to investigate the thermodynamic behavior of the samples. With increasing degree of epoxidation,
the thermal stability of the samples initially decreased, then increased at the final reacting stage. Differential scanning
calorimeter (DSC) indicated that the melting point of ESO was higher than that of soybean oil. Gel permeation chromatography
(GPC) indicated the molecular mass of the samples increased initially, then decreased, with an increase in the extent of epoxidation.
Authors:L. Xiao, Y. Zhang, Q. Li, Q. Zhang, and K. Wang
Fingernails of pathologically diagnosed normal people, light esophageal epitheliosis patients, severe esophageal epitheliosis patients and esophageal cancer patients were irradiated and their elemental contents were determined by INAA. Multivariate statistical treatment of Ca, Cl, K. Mg, Se and Zn data shows that esophageal cancer patients are distinguishable from non-cancer patients. The accuracy computed by neural networks is greater than 80%.
Authors:Li-Yun Jin, G. Capannesi, L. Renzi, and F. Sedda
A study of trace elements in hair samples from two children of different sex on different sampling dates has been carried out using INAA. Using several combinations of irradiation, cooling and counting times, about thirty elements were quantitatively determined. Some conclusions could be drawn from the data obtained.
Radioiodination of tri-n-butylstannyl-3-quinuclidinyl benzilate (TQNB) and N-succinimidyl-3-(tri-n-butylstannyl) benzoate (STB) was studied. STB was radiolabeled efficiently using iodogen to prepare radioactive N-succinimidyl-3- iodobenzoate (S125IB). TQNB was radioiodinated using Chloramine-T to obtain radioactive iodo-3-quinuclidinyl benzilate (125IQNB). Both S125IB and 125IQNB showed good stability at room temperature in the dark.
Authors:W. Li, J. Cashion, R. Pollard, and L. Brown
Treating iron-doped ZSM-5 zeolite with NO2 produced a complete change in the parameters of its 57Fe Mössbauer spectrum. The intensity of the absorption showed a dramatic decrease at 40–70 K with smooth, but anharmonic, behavior above this temperature. The results can be interpreted in terms of the modification of the iron environment to form an approximately square-well potential. This results in an asymmetric potential in which the iron becomes frozen in one region at low temperatures.
Authors:Y. Li, H. Xingen, L. Ruisen, and X. Guiying
Enthalpies of dilution of aqueous L-serine, pyridine and methylpyridine solutions and their enthalpies of mixing have been determined by a mixing-flow microcalorimeter
at 298.15 K. The data have been analyzed in terms of McMillan-Mayer formalism to fit to virial polynomials from which the
heterotactic enthalpic pairwise interaction coefficients, hxy, betweenL-serine and pyridine and methylpyridine isomers have been evaluated. The results obtained in the present paper are compared
with those reported in the earlier paper about glycine and L-alanine in the same organic solvent aqueous solutions, giving a global insight of the interaction mechanism between the a-amino
acids and pyridine and methylpyridine from the point of view of solute-solute interactions and substituent effects of methyl
groups introduced into the pyridine ring.
Conducting polyaniline/Cobaltosic oxide (PANI/Co3O4) composites were synthesized for the first time, by in situ deposition technique in the presence of hydrochloric acid (HCl)
as a dopant by adding the fine grade powder (an average particle size of approximately 80 nm) of Co3O4 into the polymerization reaction mixture of aniline. The composites obtained were characterized by infrared spectra (IR)
and X-ray diffraction (XRD). The composition and the thermal stability of the composites were investigated by TG-DTG. The
results suggest that the thermal stability of the composites is higher than that of the pure PANI. The improvement in the
thermal stability for the composites is attributed to the interaction between PANI and nano-Co3O4.
Poly(AN—co—St) (PAS) and poly(AN—St—MMA)(PASM) were synthetized by emulsion polymerisation. The glass transition temperatures (Tg) of the copolymers and the relationship between Tg and the components of the copolymers were investigated by differential scanning calorimetry. The results show that Tg for the AN—St bipolymers has apeak value in the range 115–118°C at a content of 50 mass% St. When methyl methacrylate was added, the Tg of the terpolymer was decreased by about 2–6°C.The thermostability and the activation energy E of degradation were determined by thermogravimetric analysis.
Authors:M. Bertolotti, G. L. Liakhou, R. Li Voti, and C. Sibilia
The photodeflection technique is useful not only for thermal diffusivity measurements but also to supply a thermal imaging system. The experimental setup and the basic theoretical aspects for determining the temperature profile are discussed together with the experimental results on a semiconductor laser diode.