Alumina contribution to CO oxidation: A TPR and IR study

The alumina contribution to CO oxidation in the absence of O₂ on metal oxide supported catalysts was investigated by CO TPR and in-situ FTIR and DRIFT studies up to 800 °C. These tests were performed on two Al₂O₃ supported catalysts (1 wt.% Pt/La/γ-Al₂O₃ and 8 wt.% Cu/γ-Al₂O₃) and on two corresponding alumina supports (5 wt.% La₂O₃ stabilised γ-Al₂O₃ and high mechanical resistant spherical γ-Al₂O₃ particles). The quantitative determination of CO consumption and CO₂ and H₂ formation on the alumina supports was in agreement with a WGS reaction occurring between surface OH and CO with a predominantly 2:1 stoichiometry. In the CO TPR of metal oxide supported catalysts, in addition to the reduction of the metal, a WGS reaction took place with enhanced kinetics. This enhancement was the result of a CO spillover phenomenon from the metal to alumina hydroxyls. This phenomenon significantly affected the evaluation of the reduction degree of the supported metal and could not be neglected in the subsequent calculations.     

Structural Properties Governing Retention Mechanisms on Immobilized Artificial Membrane (IAM) HPLC Columns

The aims of this study were to investigate whether three commercially available immobilized artificial membrane (IAM) HPLC columns yield collinear data for neutral compounds, and whether IAM scales are distinct from the log P_oct (partition coefficient in the octanol/H₂O system) scale. With these objectives, the retention mechanisms on the IAM HPLC columns were analysed by linear solvation free‐energy relationships (LSERs). A set of 68 neutral model compounds with known solvatochromic parameters and log P_oct values was investigated, allowing a regular and broad exploration of property space. The resulting solvatochromic equations clearly indicate that the three IAM stationary phases retain small neutral solutes by a balance of intermolecular forces closely resembling those underlying partitioning in octanol/H₂O and retention on a reversed‐phase LC‐ABZ HPLC column. For all systems, the solute's size and hydrogen‐bond‐acceptor basicity are the two predominant factors, whereas dipolarity/polarisability and hydrogen‐bond‐donor acidity play only minor roles.     

A possible measure of the energy deposition profile in additional plasma heating experiments

We suggest measuring the energy deposition profile in additionally heated plasmas by modulating, at an appropriate frequency, a fraction of the supplementary power. If the frequency is high enough the temperature oscillations occur, with appreciable amplitude, only where the energy is directly deposited. Operating at lower frequency, plasma transport properties can be studied, through the measure of the phase delay of the temperature oscillations.     

Some Rigorous Results on a Stochastic GOY Model

A stochastic infinite dimensional version of the GOY model is rigorously investigated. Well posedness of strong solutions, existence and p-integrability of invariant measures is proved. Existence of solutions to the zero viscosity equation is also proved. With these preliminary results, the asymptotic exponents ζ_p of the structure function are investigated. Necessary and sufficient conditions for ζ₂≥ 2/3 and ζ₂=2/3 are given and discussed on the basis of numerical simulations.     

Inclusion Complexation of Carbaryl and β-Cyclodextrin in Solution and in the Solid State

This study was carried out with the aim ofinvestigating the interactions between-cyclodextrin and carbaryl, a carbamatepesticide, and their effect on some physico-chemicalproperties of carbaryl, such as aqueous solubility andlipophilicity. The interactions between carbaryl and-cyclodextrin were thoroughly investigated bothin solution and in the solid state. The effect of-cyclodextrin on the aqueous solubility ofcarbaryl was evaluated by the phase solubility method.The amount of carbaryl dissolved increased linearlywith the addition of -cyclodextrin according toan A_L type plot and without precipitation of thecomplex. The apparent stability constant of thecomplex was 289 ± 21 M^-1, assuming a 1 : 1stoichiometry; this value was confirmed by a methodbased on circular dichroism measurements.Equimolar carbaryl/-cyclodextrin solid systemswere prepared by physical-mixing and freeze-drying,and fully characterised by Differential ScanningCalorimetry, X-ray powder diffractometry and FourierTransform Infra-Red analysis. The results of the solidstate study demonstrated that the freeze-drying methodyields a system with a high degree of amorphisationand yields an inclusion complex.The dissolution profile of the pesticide was affectedby the physico-chemical properties of each solidsystem, the freeze-dried form dissolving more rapidly. However, the physical association of-cyclodextrin and carbaryl enhanced the aqueoussolubility of the insecticide as well.     

Evidence for PSII donor-side damage and photoinhibition induced by cadmium treatment on rice (Oryza sativa L.)

The effects of cadmium (from 7.5 to 75 microM) on chloroplasts of rice were studied at the structural and biochemical level. Loss of pigments, reduction of thylakoids and decrease in oxygen evolution and Fv/Fm ratio occur in leaves following cadmium treatment. However, the amount of photosystem II reaction center proteins and that of its light harvesting complex is not affected, indicating that cadmium does not adversely influence the structural organization of this photosystem. In thylakoids isolated from cadmium-treated plants a loss in the capability to reduce 2,6-dichlorophenolindophenol is observed, which is partially restored if diphenylcarbazide is used as an electron donor, indicating that cadmium affects water splitting activity. In thylakoids isolated from control plants and treated with cadmium, diphenylcarbazide preserves most of the photosystem II activity lost after incubation with cadmium; most of the S(2) multiline electron paramagnetic resonance signal from the manganese cluster is lost, whereas the TyrD(+) and other signals are retained. Light-induced photosystem II damage, in vitro, is promoted by Cd-treatment as deduced from the mobility shift of the D1 protein observed by immunoblot.     

Accuracy of the random-incidence scattering coefficient measurement

The experimental results presented in this study aim at providing an useful insight into the accuracy of the measurement procedure of the random-incidence scattering coefficient as defined in ISO 17497-1:2004. A systematic experimental investigation has been conducted in a full-scale reverberation room. The tested diffusers are characterized by different geometrical distributions of hollow wooden cubes with an edge length of 20 cm, and different configurations of the measurement set-up. The accuracy of the measurement results has been evaluated considering the contribution of the different undefined aspects of the ISO method such as the microphones height, the air gap underneath the turntable, the sample shape, and the correction of the effects of the absorption and scattering coefficients of the base plate. The results showed that the accuracy of the measurement increases when a more rigid turntable and a circular sample are used, and when the air gap below the turntable is covered. Furthermore, the distance of the microphones from the sample surface was found to affect significantly the results, thus to influence the accuracy of the measurements.     

Scenedesmus dimorphus (Turpin) Kützing growth with digestate from biogas plant in outdoor bag photobioreactors

Digestate coming from an Anaerobic Digestion unit in a Biogas Plant, feeded on cow manure and vegetable waste from markets, has been used. About 8–35 L polyethylene transparent bags have been employed as cultivation container, outdoor. Different aliquots of digestate, alone or mixed with commercial liquid fertiliser, were employed to cultivate in batch Scenedesus dimorphus, a freshwater green microalga, in the ENEA facilities of Casaccia Research Center, near Rome, Italy. The cultivation period was June–July 2013. The average daily yields of dry microalgae biomass varied from 20 mg/L/d to 60 mg/L/d, mean 38.2 mg/L/d. Final dry biomass concentration varied from 0.18 to 1.29 g/L, mean 0.55 g/L. S. dimorphus proved to be very efficient in removing N and P from the culture medium. Another fact emerged from these trials is that S. dimorphus inner composition resulted to be variable in response to the tested different culture conditions.