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Obesity is the result of energy intake chronically exceeding energy expenditure. Classical treatments against obesity do not provide a satisfactory long-term outcome for the majority of patients. After the demonstration of functional brown adipose tissue in human adults, great effort is being devoted to develop therapies based on the adipose tissue itself, through the conversion of fat-accumulating white adipose tissue into energy-dissipating brown adipose tissue. Anti-obesity treatments that exploit endogenous, pharmacological and nutritional factors to drive such conversion are especially in demand. In the present review, we summarize the current knowledge about the various molecules that can be applied in promoting white-to-brown adipose tissue conversion and energy expenditure and the cellular mechanisms involved.

The selective adsorption of carbon dioxide−methane mixtures in AlPO4-5 and MCM-41 materials have been studied using gas chromatography mass spectrometry and Grand Canonical Monte Carlo computer simulations. AlPO4-5 and MCM-41 are molecular sieves consisting of uniform arrays of unidimensional pore channels. The materials were shown to be selective for carbon dioxide under all conditions studied. There was qualitative agreement between experimental and simulation adsorption and selectivity data. Any discrepancies that were observed were attributed to the effect of pore blocking by adsorbate molecules, which was not accounted for in the simulation model. In the case of MCM-41, quantitative differences in selectivity were the result of the simplistic models of MCM-41 used in the simulations. Partial interaction potential models were used in Monte Carlo calculations to determine the factors that effect carbon dioxide selectivity over methane. Molecular shape and fluid−wall interactions were found to have a si...

Cu-ZnO-Al2O3 catalysts for methanol oxidative steam reforming were prepared from mixed Cu/Zn/Al hydroxycarbonates obtained from metal nitrates or chlorides by the method of homogeneous precipitation. The samples were characterized by XRPD, TG/DTA, N2 adsorption, FTIR, TPR, NH3-TPD. The Cu dispersion was measured by reaction with N2O. Less reducible Cu species and higher concentration of acid sites were found in the catalysts derived from metal chlorides. The Cu dispersion did not depend on the nature of the precursor salts. All catalysts appeared very active, giving almost complete CH3OH conversion at 300-350°C and H2 yield up to the maximum allowed by the feeding composition. The hydrogen production rate increased with Cu content and was higher for catalysts derived from nitrates. The activation energy of the reaction was correlated with surface acidity, suggesting that the oxide matrix was involved in methanol adsorption and dissociation

Cu/ZnO/Al2O3 catalysts derived from layered double hydroxides precursors, prepared by a modified urea method were studied for the oxidative steam reforming of methanol (OSRM), with the aim of investigating on the influence of the composition and chemical properties on the catalytic activity. The materials were characterized by XRPD, FTIR, TPR. The redox properties of the catalysts were markedly influenced by the Cu concentration and probably by the phase composition of the precursors. The catalytic tests, carried out at T=200-400°C, H2O/CH3OH/O2=1.1/1/0.12 and GHSV=60000 h-1, showed CH3OH conversion and H2 yield strongly influenced by the chemical composition. The correlation of H2 production rate with Cu and Al content allowed to identify a range of optimal composition

Summary form only given, as follows. The scaling of the neutron yield Y from D+D reactions and, specifically, of its fluctuations /spl Delta/Y from discharge to discharge was experimentally determined with four plasma focus machines, as a function of the peak plasma-current density J. The powering energy levels were W=6 kJ for one PF machine (PF/sub 1/), 20 kJ for two identical PF machines [but one (PF/sub 2/) with, the other (PF/sub 3/) without, field distortion element at the electrode breech to sharpen the plasma current distribution], 35 kJ and 50 kJ for a fourth machine (PF/sub 4/). The comparative tests at 20 kJ and 35 kJ had the same peak electrode current I=1 MA the same charging voltage of the capacitor bank 25 kV, the same ratio inductance/capacitance (L/C), but with C(PF/sub 4/)=2C(PF/sub 2/) and L(PF/sub 4/)/spl equiv/[T(PF/sub 4/)/2/spl pi/]/sup 2//C(PF/sub 4/)=2L(PF/sub 2/). T(PF/sub 4/)/spl sime/1.4 T(PF/sub 4/), is the measured period of the complete PF electric circuit, including the propagating current sheet between coaxial electrodes. The bearing on Y, /spl Delta/Y of the breech overvoltage during the pinch collapse and of the variations of J is experimentally determined. The data indicate that MaxY(PF/sub 4/)/spl sime/mean value Y/sub Av/(PF/sub 2/) of Y, Y/sub Av/(PF/sub 2/)/spl sime/3Y/sub Av/(PF/sub 3/). The neural network analysis connecting Y and the current sheet multiplicity in the same discharge, was carried out as in earlier experiments.

Summary form only given. The neutron yield per pulse (Y/sub n/) from D+D reactions, the thickness and speed of the leading plasma current sheath in the electrode gap, and the multiplicity (/spl upsi/) of current sheaths in one discharge have been monitored in two plasma focus machines operating at different levels of the capacitor bank energy, 5 kJ /spl les/ W /spl les/ 10 kJ and 12 kJ /spl les/ W /spl les/ 30 kJ. The time spacing (/spl Delta/ t) between the leading (CS/sub 1/) and trailing (CS/sub 2/) current sheath is also recorded up to a CS distance 4 = 1.7 cm from the center electrode (anode) axis. The scaling of Y/sub n/ /spl sim/ A W/sup 2/ is tested for PF-Mather-geometry machines with a field distortion element (FDE) inserted at the breech side of the electrode gap, which increases Y/sub n/ (i.e., the constant A) by a factor /spl ges/ 5 above the Y/sub n/ value of the same machines operating under identical conditions, but without FDE.

Resistivity, Hall effect and magnetoresistivity measurements in Fe−Ni alloy specimens with Ni content ranging from 29 to 32 wt.% and subjected to martensitic transformation have been performed. The results have been interpreted by considering both the mechanisms of the martensitic transformation, different in 29 and 30 wt.% Ni alloys from that in 31 and 32 wt.% Ni ones, and the theories of Smith and Berger on the Hall effect in dilute ferromagnetic alloys, which have been applied to the above-described alloys. The Hall data, analysed by means of Kohler polts, have allowed us to identify the charge carrier scattering mechanisms prevailing in the different alloys,i.e. the skew scattering in 29 and 30 wt.% Ni alloys and the side jump scattering in 31 and 32 wt.% Ni ones.

Magnetoelastic measurements have been performed on some tubular Ni samples in order to study the initial magnetization curves as depending on the sequence twist demagnetization or vice versa. The experimental results pointed out that, if the torsion comes before the demagnetization, it causes an anisotropic demagnetization along the compression helix of the torsion. On the contrary, when the demagnetization precedes the torsion, a nucleation and growth of the new domain walls occur. These conclusions are supported by Gavoille theory.

Iron-nickel alloys in the range from 29 to 32 wt.% Ni have been irradiated with an integral flux of 3·1018 n cm−2 and then subjected to martensitic transformation. the resistivity, magnetoresistivity and Hall-effect measurements performed on the irradiated samples allow us to support the formation of iron-rich or nichel-rich ordered microstructures and additional α-phase from the supersaturated γ-matrix. The nickel content of the above-ordered region, is evaluated from the behaviour of the anomalous Hall effect in the irradiated specimens with different composition.

Catalysts for oxidative methanol reforming were prepared by thermal and H 2 -reduction treatments of a precursor consisting mainly of a hydrotalcite-like Cu–Zn–Al hydroxycarbonate and a Zn-rich paratacamite. The precursor was obtained by homogeneous precipitation of metal cations with a properly modified urea method. XRPD and quantitative Rietveld analysis of the precursor material revealed the presence of hydrotalcite and paratacamite phases in a weight ratio 3:1. Treatment in situ of the precursor produced Cu/ZnO/Al 2 O 3 (Cu = 18%, Zn = 33%, Al = 49% mol) catalysts. Chemical properties of the precursor and of the catalysts were studied by TPR, TPO, NH 3 -TPD, N 2 O chemisorption, FTIR, and UV–vis techniques. Physical characterization was carried out by the SEM, EDS, XRPD, TG/DTA, and N 2 adsorption techniques. The influence of heating rate of the precursor was investigated. Heat-treated samples contained CuO, ZnO, and amorphous Al 2 O 3 , and probably ZnAl 2 O 4 , as suggested by XRPD and FTIR measurements. The crystallinity of oxide phases was higher for the sample treated with a lower heating rate that also showed lower surface area and lower Cu dispersion. The presence of Cu 2+ in octahedral sites of alumina was suggested by UV–vis spectra. CO adsorption gave evidence of easy reduction of Cu(II) to Cu(I) and Cu(0) and the formation of stable complexes with Cu(I). NH 3 -TPD and FTIR measurements showed the presence of surface acid sites of the Lewis type with wide strength distributions, mainly due to Zn 2+ and Al 3+ cations. Cu(II) was able to oxidize NH 3 , while Cu(0) activated NH 3 decomposition. TPR and TPO measurements indicated that Cu species are easily reduced and reoxidized and Cu(I) species are intermediate for both processes. The redox properties appeared to be influenced by the rate of the previous heat treatment.

Co-H-MFI and Co-H-FER were studied as catalysts for NO reduction with methane, under diluted conditions. Catalyst bulk and surface structure was characterised by chemical analysis, XRD, TG-DTA, SEM micrographs, IR studies, UV–vis spectroscopy, ammonia TPD, and TPR. Only the features due to zeolitic frameworks were observed. The UV–vis spectra showed that, after outgassing, Co ions are mainly present as Co 2+ . FT-IR detected residual bridging hydroxyl and silanol groups in spite of the apparent over-exchange, deduced from the chemical analysis. Co ions gave rise to Lewis acid sites of medium strength, evidenced through in situ analysis of the adsorption of a basic probe molecule. NH 3 -TPD measurements fully confirmed these results. TPR measurements detected easily reducible and oxidizable Co species, possibly related to nanosized Co oxide phases, together with hardly reducible Co 2+ ions. Catalytic tests highlighted the Co-H-FER and Co-H-MFI activity, both in NO-selective catalytic reduction by methane and in NO oxidation to NO 2 , the latter being the predominant reaction at low temperatures. Some mechanistic features of the CH 4 -SCR reaction are discussed.