Supercritical CO2 for the drying and microbial inactivation of apple's slices

Supercritical CO2 (Sc-CO2) drying has been recognized as a promising low temperature drying technique for food products. In this regard, this work focuses on the feasibility of Sc-CO2 drying of apple’s slices: both the microbiological stability and mechanical behavior of the test product after the process have been investigated in dependence from different process parameters, namely drying time, pressurization time, and depressurization time. The microbiological stability was determined for both inoculated pathogenic bacteria (Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes) and naturally present microorganisms (yeasts and molds, mesophilic bacteria and spores and Enterobacteriaceae). Results demonstrated a complete inactivation of pathogenic bacteria under the detection limit (<1 CFU/g) just after the pressurization (10 min) and depressurization (20 min) phases. After the same steps, a strong reduction of vegetative bacteria and yeasts and molds was also observed in comparison with air drying and freeze drying samples. As regards the mechanical behavior, the Young Modulus, measured before and after the CO2 processes to provide a measurement of samples’ stiffness, resulted dependent from the final water activity, but independent from the length of pressurization and depressurization phases at longer drying time. Overall, these results are promising to foster the development of the technology at industrial level

Clinical outcome of skin yaws lesions after treatment with benzathinebenzylpenicillin in a pygmy population in Lobaye, Central African Republic

<p>Abstract</p> <p>Background</p> <p>Yaws is a bacterial skin and bone infectious disease caused by <it>Treponema pallidum pertenue</it>. It is endemic, particularly among pygmies in Central African Republic. To assess the clinical cure rate after treatment with benzathinepenicillin in this population, we conducted a cohort survey of 243 patients in the Lobaye region.</p> <p>Findings and conclusion</p> <p>The rate of healing of lesions after 5 months was 95.9%. This relatively satisfactory level of therapeutic response implies that yaws could be controlled in the Central African Republic. Thus, reinforcement of the management of new cases and of contacts is suggested.</p

Move3D: a generic platform for path planning

This paper reports on Move3D, a software platform dedicated to collision-free path planning. The algorithms are based on probabilistic approaches and take advandtage of the progress of computer performance. The generality comes from a dedicated software architecture allowing a rapid design of path planners. The paper focuses on recent results obtained in logistics for industrial installations, in graphics animation and in mobile robotics as well. 1 Introduction Path planning has been an active research field in robotics for more than 20 years [26]. Algorithms become more and more mature. Moreover, they take advantage of the increasing progresses of computer speed: with the same algorithms, it is today possible to solve problems which were out of scope five years ago. The range of the potential applications of path planning algorithms becomes broader. This paper presents the software plateform Move3D currently developed at LAAS for generic multipurpose applications. From an algorithm..

Monte Carlo Aggregation Code (MCAC) Part 2: Application to soot agglomeration, highlighting the importance of primary particles

International audienceDuring the agglomeration of nanoparticles, notably soot, a change in both the flow regime (from free molecular to near continuum) as well as the change of agglomeration regime (from ballistic to diffusive) is expected. However,these effects are rarely taken into account in numerical simulations of particles agglomeration and yet, they are suspected to have an important impact on the agglomeration kinetics, particle morphologies and size distributions. Thiswork intends to study these properties by using the MCAC presented in the preceding work (part 1) by focusing on the physical impact of varying the particle volume fraction and monomers size and polydispersity. The results show an important sensitivity of the kinetics of agglomeration, coagulation homogeneity and agglomerates morphology to the size of monomers. First, for smaller monomers diameters the agglomeration kinetic is enhanced and agglomerates are found to be more compact, characterized by larger fractal dimensions. Secondly, for large monomer diameters, fractal dimensions down to 1.67 can be found being therefore, smaller than the classical 1.78 for DLCA mechanism. One important conclusion is that variation in time of both the agglomeration and flow regimes has to be considered for a more accurate simulation of the agglomerates size distribution and morphology

Extreme differences in oxidation states : Synthesis and structural analysis of the germanide oxometallates A 10[Ge 9] 2[WO 4] as well as A 10+x[Ge 9] 2[W 1-xNb xO 4] with A = K and Rb containing [Ge 9] 4- polyanions

Semitransparent dark-red or ruby-red moisture- and air-sensitive single crystals of A 10+x[Ge 9] 2[W 1-xNb xO 4] (A = K, Rb; x = 0, 0.35) were obtained by high-temperature solid-state reactions. The crystal structure of the compounds was determined by single-crystal X-ray diffraction experiments. They crystallize in a new structure type (P2 1/c, Z = 4) with a = 13.908(1) Å, b = 15.909(1) Å, c = 17.383(1) Å, and α = 90.050(6)° for K 10.35(1)[Ge 9] 2[W 0.65(1)Nb 0.35(1)O 4]; a = 14.361(3) Å, b = 16.356(3) Å, c = 17.839(4) Å, and α = 90.01(3)° for Rb 10.35(1)[Ge 9] 2[W 0.65(1)Nb 0.35(1)O 4]; a = 13.8979(2) Å, b = 15.5390(3) Å, c = 17.4007(3) Å, and α = 90.188(1)° for K 10[Ge 9] 2WO 4; and a = 14.3230(7) Å, b = 15.9060(9) Å, c = 17.8634(9) Å, and α = 90.078(4)° for Rb 10[Ge 9] 2WO 4. The compounds contain discrete Ge 9 4- Wades nido clusters and WO 4 2- (or NbO 4 3-) anions, which are packed according to a hierarchical atom-to-cluster replacement of the Al 2Cu prototype and are separated by K and Rb cations, respectively. The alkali metal atoms occupy the corresponding tetrahedral sites of the Al 2Cu prototype. The amount of the alkali metal atoms on these diamagnetic compounds corresponds directly to the amount of W substituted by Nb. Thus, the transition metals W and Nb appear with oxidation numbers +6 and +5, respectively, in the vicinity of a [Ge 9] 4- polyanion. The crystals of the mixed salts were further characterized by Raman spectroscopy. The Raman data are in good agreement with the results from the X-ray structural analyses