Revealing the Phenotypic and Genomic Background for PHA Production from Rapeseed-Biodiesel Crude Glycerol Using Photobacterium ganghwense C2.2

Polyhydroxyalkanoates (PHA) are promising biodegradable and biocompatible bioplastics, and extensive knowledge of the employed bacterial strain’s metabolic capabilities is necessary in choosing economically feasible production conditions. This study aimed to create an in-depth view of the utilization of Photobacterium ganghwense C2.2 for PHA production by linking a wide array of characterization methods: metabolic pathway annotation from the strain’s complete genome, high-throughput phenotypic tests, and biomass analyses through plate-based assays and flask and bioreactor cultivations. We confirmed, in PHA production conditions, urea catabolization, fatty acid degradation and synthesis, and high pH variation and osmotic stress tolerance. With urea as a nitrogen source, pure and rapeseed-biodiesel crude glycerol were analyzed comparatively as carbon sources for fermentation at 20 °C. Flask cultivations yielded 2.2 g/L and 2 g/L PHA at 120 h, respectively, with molecular weights of 428,629 g/mol and 81,515 g/mol. Bioreactor batch cultivation doubled biomass accumulation (10 g/L and 13.2 g/L) in 48 h, with a PHA productivity of 0.133 g/(L·h) and 0.05 g/(L·h). Thus, phenotypic and genomic analyses determined the successful use of Photobacterium ganghwense C2.2 for PHA production using urea and crude glycerol and 20 g/L NaCl, without pH adjustment, providing the basis for a viable fermentation process.     

Addressing the Risk of Surface Water Intrusion in Old Romanian Salt Mines

In Romania, surface waters near underground salt mines represent a significant risk to the stability of the mine workings. Such problems occur in many salt exploiting facilities, i.e. Slanic Prahova, Targu Ocna, Praid. In this paper, the authors present a method of dealing with this issue at the Praid salt mine with research targeted at avoiding the hazard presented by intrusion of surface waters into old mine workings. Monitoring activities are proposed to prevent damage due to the seepage of Corund Creek water into the subsurface salt body, which could compromise and even produce collapses in the salt mine sanatorium and old and new mines.     

Reduced floating body effects in narrow channel SOI MOSFETs

An experimental demonstration is given of the reduction of floating body effects in narrow channel SOI MOSFETs, as manifested by the saturation region subthreshold characteristics, latch-up, and breakdown voltage. The mechanisms responsible for this reduction are explained by original experiments and simulations. These are a deterioration of the carrier lifetime near the channel edges caused by local stress and defects, and a lowering of the source-body built-in potential barrier, resulting from dopant outdiffusion/segregation into the isolation oxide     

Optimizing polarization states in a figure-8 laser using anonreciprocal phase shifter

The polarization states in a figure and laser are analyzed using Jones matrices. The analysis shows that a figure-8 laser in CW operation does not give enough information to allow the optimization of the birefringence for mode-locking. A switchable nonreciprocal phase shifter is proposed to provide a simple way to optimize the birefringence for a mode-locked figure-8 laser. Using this device, the mode-locking of a diode-pumped figure-8 laser was started, with a probability better than 99%, by following a sequence of predetermined mechanical adjustment. With the proposed nonreciprocal phase shifter, the optimization and starting of a figure-8 laser can easily be automated     

Conformal anodic oxidation of aluminum thin films

Membrane-based synthesis, also called template synthesis, is a very general approach used to prepare arrays of nanomaterials with monodispersed geometrical features. The most commonly used porous templates are track-etched polycarbonate and porous anodic alumina membranes. Common to all these templates is the fact that the pores are perpendicular to the surface of the membrane. Here, a novel approach is presented, where the pores are synthesized parallel to the surface of the membrane. For the first time, the anodic oxidation of an aluminum thin film is performed laterally, i.e., parallel to the surface of the substrate, instead of perpendicular as usually done. For low anodic oxidation voltages (between 3 and 5 V) we obtain highly regular and ordered pore arrays, at least over a few hundred nanometers length, with a minimum pore size of approximately 3 to 4 nm. With such porous alumina structures, the controlled in-plane organization of arrays of template-grown nanowires and carbon nanotubes for reproducible device fabrication should be much easier.     

Latch and hot-electron gate current in accumulation-mode SOIp-MOSFET's

Simultaneous measurements of drain and gate currents in short-channel accumulation-mode SOI p-MOSFET'MOs demonstrate that a latch mechanism may occur in these devices and induce an anomalous behavior of the hot-electron gate current: distortion of I_g(V _g) curves, hysteresis and excessively high gate current values. 2-D MEDICI simulations based on the lucky-electron model qualitatively reproduce the measurements in the latch regime, and explain the unusual gate current dependence on drain and gate biases. The results are of relevance for reliability and modeling issues     

PARAMETERS ESTIMATION FOR A FIRST ORDER IRREVERSIBLE REACTION. A STOCHASTIC APPROACH

A first order irreversible reaction is investigated using a stochastic model in order to account for the perturbations inherent to any chemical process. The main conclusion is that the concentration is distributed according to a lognormal law rather than to a normal one. This approach leads to a maximum likelihood estimate of the kinetic constant which is different with respect to the usual least squares estimate. Moreover, the stochastic model allows us to predict not only the expected value of the concentration, but to get a confidence interval, too. Statistical tests are provided in order to detect outliers, high-leverage and influential points.     

Polarization Induced Spin Wave Damping in Spin Polarized Liquid 3He–4He

We have measured the temperature and polarization dependence of Silin spin wave spectra in a saturated ³He–⁴He mixture with a concentration of 9.4% at a pressure of 8 bars. The mixture has been cooled and polarized by a Leiden dilution refrigerator to temperatures in the range 10–15 mK and polarizations as high as 9.2% corresponding to 3.4 times the equilibrium polarization of 2.7% in the external magnetic field of 11.36 T. The analysis takes into account the dipolar interactions and results in the relaxation time τ _⊥ and spin diffusion constant D _⊥ . We find that τ _⊥ and D _⊥ are proportional to where T is the temperature, is the polarization enhancement factor and T _a0 is the anisotropy temperature for the mixture at equilibrium in the external field. Our result T _a0=3.66±0.14 mK is 30% higher than the theoretical prediction for very dilute mixtures and is evidence for the existence of polarization induced relaxation of transverse spin currents.