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Thermal properties of several vegetable oils such as soy, corn, and avocado commercial oils were obtained by using a photopyroelectric technique. The inverse photopyroelectric configuration was used in order to obtain the thermal effusivity of the oil samples. The theoretical equation for the photopyroelectric signal in this configuration, as a function of the incident light modulation frequency, was fitted to the experimental data in order to obtain the thermal effusivity of these samples. The obtained results are in good agreement with the thermal effusivity reported for other vegetable oils. All measurements were done at room temperature.

Thermal properties of liquids used in the automobile industry such as engine oil, antifreeze, and a liquid for windshield wipers were obtained using the photopyroelectric (PPE) technique. The inverse PPE configuration was used in order to obtain the thermal effusivity of the liquid samples. The theoretical equation for the PPE signal in this configuration, as a function of the incident light modulation frequency, was fitted to the experimental data in order to obtain the thermal effusivity of these samples. Also, the back PPE configuration was used to obtain the thermal diffusivity of these liquids; this thermal parameter was obtained by fitting the theoretical equation for this configuration, as a function of the sample thickness (called the thermal wave resonator cavity), to the experimental data. All measurements were done at room temperature. A complete thermal characterization of these liquids used in the automobile industry was achieved by the relationship between the obtained thermal diffusivities and thermal effusivities with their thermal conductivities and volumetric heat capacities. The obtained results are compared with the thermal properties of similar liquids.

We have presented general ideas to develop a new theoretical methodology, based on molecular simulation and equations of state, for obtaining the phase envelope and to predict pressure, volume, temperature (PVT) conditions of asphaltene precipitation by only taking into account the composition of the heavy crude oil and an asphaltene average molecular structure. Those results show that asphaltene precipitation is a reversible thermodynamic process. The precipitated phase is a liquid phase which consists of mainly asphaltene and some heavy fractions from the crude. This methodology can be applied to find complete phase diagrams of different crude oils based on an asphaltene average molecular structure and the composition of crude oil.

CdS polycrystalline thin films prepared onto glass substrates by the chemical bath deposition method at 80°C showed cubic crystalline structure (β-CdS). Upon thermal annealing in Ar + S2 flux at different temperatures in the range 200–510°C, the crystalline structure evolution of layers from the cubic modification (as-grown sample) to hexagonal phase (annealed at highest temperature samples) has been observed. At around 300°C the critical point of the phase transition has been experimentally determined to occur. Raman spectroscopy measurements were carried out at room temperature for as-grown and annealed layers. The A1(LO) + E1(LO) modes at 305 cm−1 and replicas appear for as-grown and annealed samples. The E1(TO) and the A1(TO) modes were also observed. A classic simple approach is proposed in order to explain the presence of the TO modes.

"Ab initio density functional calculations are performed for a toroidal carbon C 120 nanostructure doped with one to ten calcium atoms bonded to its outer surface. The calculations are based on DFT with the generalized gradient approximation PW91 (Perdew and Wang) as implemented in the Materials Studio v.4.3 code. Dmol 3 module is used to calculate, among others, total energies, charge density, HOMO- LUMO and Mulliken population analysis. Based on these results, it is possible to propose that a single Ca atom is able to adsorb up to 6 H 2 molecules. The study is extended for a system with ten Ca atoms, which can adsorb up to 60 H 2 molecules. This leads to 6.16 weight percentage for the gravimetric hydrogen storage capacity which fulfills the US Department of Energy (DOE) target (6 wt%) for onboard hydrogen storage systems for the year 2010. Accordingly, the calcium-coated toroidal carbon C 120 nanostructure is a good quality candidate for H 2 storage with higher adsorption energy than on pristine carbon nanotorus."

Ab initio density functional calculations were performed for a toroidal carbon C120 nanostructure. Hydrogen molecules, n = 1–15, were added inside the nanotorus and for each one of these systems a geometry optimization was obtained. The cohesive energy shows that these structures are energetically stable. For example, the binding energies are −34.95 and −36.19 Hartrees and the interatomic distances HH are 0.753 and 0.772 A for 1 and 14 molecules, respectively. Considering only molecular hydrogen, we have always seen so far weak physisorption into the C120 nanotorus. There is no chemisorption until the number oh hydrogen molecules are increased to 14. In this case, four hydrogen atoms are chemisorbed. With 15 molecules, there are 10 hydrogen atoms chemisorbed just at the inner nanotorus surface forming 10 HC bondings with bond length close to that in methane. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem 110:2495–2508, 2010