Thermal conductivity of lipidic emulsions and its use for production and quality control

Thermal conductivity of lipidic emulsions has been experimentally determined by the probe method. To this purpose a special probe has been designed and built in laboratory, with small diameter (0.6 mm) and a high length to diameter ratio (100). The temperature sensor of the probe (type T thermocouple) and the heater (Pt wire) were properly calibrated. Moreover, the probe performance has been tested by means of a pure liquid (glycerin) having well known thermal conductivity by literature. Differences of about 1.5% at ambient temperature in thermal conductivity values between literature and experiments were found. On lipidic emulsions first thermal conductivity has been measured in the temperature range 1040°C, second the same property as a function of time at constant temperature (40°C), then the values after freezing at –15°C and reheating at 20 °C; and last the kinetics of degeneration. Results show a significant difference between thermal conductivity values of a new emulsion (0.51 W/m K), compared with the creamed one (0.62 W/m K), and the decayed one (0.68 W/m K ). It has also put into evidence why the frozen emulsion cannot be used for intravenous injection, i.e. viscosity increases because of breaking of the oil particles. Finally information about the kinetics of the degeneration process have been obtained. The uncertainty resulting from the calibration and tests justifies the possible use of the measurement technique for process control of production, and also for quality control in the clinical practice

Recovery trends of commercial fish: the case of an underperforming Mediterranean marine protected area

Temporal trends in the recovery of exploited species in marine protected areas (MPAs) are useful for a proper assessment of the efficacy of protection measures. The effects of protection on the fish assemblages of the sublittoral rocky reefs in the \u201cPenisola del Sinis-Isola di Mal di Ventre\u201d MPA (W. Sardinia, Italy) were evaluated using a multi-year series of data. Four surveys, conducted 7, 10, 13 and 15 years after the area was designated as an MPA and carried out in the period spanning June and July, were used to estimate the abundance and biomass of commercial species. The surveys were carried out in zones with decreasing levels of fishing restrictions within the MPA (zones A, B, C) and in unprotected zones (OUT1 and OUT2), and underwater video visual census techniques were used. Protected zones only occasionally showed higher levels of abundance or biomass, and the trajectories of those metrics were not consistent across the years. In addition, the zone with the highest level of protection (zone A) never presented levels of abundance and biomass higher than those in zones B and C. This study shows that even 15 years after designation, protection has had no appreciable effect in the MPA studied. It is argued that this is emblematic of several shortcomings in the planning, regulation and enforcement frameworks of the MPA

Data from docking simulations to develop an efficient strategy able to evaluate the interactions between RAGE and MDA-induced albumin adducts

This data article contains the results of docking simulations performed in order to develop a suitable in silico strategy able to assess the stability of the putative complexes between RAGE and MDA induced adducts on human albumin as experimentally determined doi: 10.1016/j.redox.2016.12.017, (Degani et al., 2017) [1]. The docking simulations involved different approaches to give a simplified yet realistic representation of the protein adducts and their environment. With increasing complexity, simulations involved the corresponding albumin tripeptides and pentapeptides with the modified residue in the central position as well as pseudo-structures which were generated by collecting the albumin residues around the adducted residue within a sphere of 7.5 \uc5 and 5 \uc5 radius. The reliability of the tested approaches was assessed by monitoring the score differences between adducted and unmodified residues. The obtained results revealed the greater predictive power of the spherical pseudo-structures compared to the simple tri- or pentapeptidic sequences thus suggesting that RAGE recognition involves residues which are spatially close to the modified residue even though not necessarily adjacent in the primary sequence

Temperature increase during composites polymerisation using two LED curing lights

The aim of curing light technology has been the development of lights that would result in faster curing of resin composites and less heat generation (Aravamudhan et al., Dent Mater 2006). The purpose of this in vitro study was to evaluate thermal changes on the tooth structures during the exposure of two different light emitting diode curing units (LED)

Experimental Investigation on Thermal Diffusivity of PM Steels

The scanty literature data on thermal diffusivity of P/M steels seems contradictory, if the cooling speed on quenching is the evaluation parameter. Due to the basic importance of diffusivity on the response of P/M steels to heat-treating, an experimental survey has been carried out, to collect data on various P/M steels, based on prealloyed, or diffusion-bonded, or admixed powders. The study has also covered the influence of processing parameters, such as compaction pressure and sintering temperature. The flash method has been used to measure the thermal diffusivity of P/M steels. This method directly measures the thermal diffusivity of a sample in slab shape. A plane-parallel sample is inserted in the test apparatus and then a short light pulse, produced by a laser or a flash lamp, heats the front surface of the sample. The heat diffuses through the sample, leading to a temperature rise on the sample rear surface. An infrared detector measures this temperature rise, versus time, and thermal diffusivity is derived from the least square regression on the whole temperature trend, using the analytical solution of heat conduction. The results show that thermal diffusivity increases as density increases. This achievement can be justified by a simple theoretical analysis of the thermal conductivity on thermal diffusivity. The collected data also enable us to ascertain the influence of sintered material composition and carbon content on thermal diffusivity. The results should contribute to clarify some uncertainties and perplexities on the behavior of properly elaborated P/M steels, to be hardened by heat treatment, conventional – such as oil quenching – or innovative, such as sinter -hardening

Experimental Tests of Conduction/Convection Heat Transfer in Very High Porosity Foams with Lattice Structures, Immersed in Different Fluids

This experimental work presents the results of measurements of thermal conductivity lambda and convection heat transfer coefficient h on regular structure PLA and aluminium foams with low density ratio (similar to 0.15), carried out with a TCP (thermal conductivity probe), built by the authors' laboratory. Measurements were performed with two fluids, water and air: pure fluids, and samples with the PLA and aluminium foams immersed in both fluids have been tested. Four temperatures (10, 20, 30, 40 degrees C) and various temperature differences during the tests Delta T (between 0.35 and 9 degrees C) were applied. Also, tests in water mixed with 0.5% of a gel (agar agar) have been run in order to increase the water viscosity and to avoid convection starting. For these tests, at the end of the heating, the temperature of the probe reaches steady-state values, when all the thermal power supplied by the probe is transferred to the cooled cell wall; thermal conductivity was also evaluated through the guarded hot ring (GHR) method. A difference was found between the results of lambda in steady-state and transient regimes, likely due to the difference of the sample volume interested by heating during the tests. Also, the effect of the temperature difference Delta T on the behaviour of the pure fluid and foams was outlined. The mutual effect of thermal conductivity and free convection heat transfer results in being extremely important to describe the behaviour of such kinds of composites when they are used to increase or to reduce the heat transfer, as heat conductors or insulators. Very few works are present in the literature about this subject, above all, ones regarding low-density regular structures