Steady state long pulse tokamak operation using Lower Hybrid Current Drive

Steady-state long pulse operation of tokamaks requires fully non-inductive current drive, thus an external current drive method. Lower Hybrid Current Drive is recognized as one of the most efficient technique used in the present day tokamaks. Progress of the conceptual design of the LHCD ITER relevant system is reported, as well as critical technology issues.     

Theory for a new full-vectorial beam-propagation method in anisotropic structures

We present a theoretical model of light-beam propagation in anisotropic and inhomogeneous dielectric structures obtained as a direct extension of the scalar fast-Fourier-transform beam-propagation method. We solve Maxwell's equations in a generalized geometrical optics approximation, in which the reflected fields are neglected. This is a full-vectorial model because it accounts for the polarization effects that are due to both the anisotropy and the inhomogeneity of the medium.     

Retardation of the phase segregation of liquid mixtures with a critical point of miscibility

The phase transition extraction (PTE) process consists of bringing a partially miscible mixture from the single‐phase to the two‐phase region of its phase diagram. Its most important characteristic is that the resulting phase separation is very fast, and hardly affected by coalescence‐retarding impurities. In this work we study two counter‐cases, where the PTE process appears to be severely retarded. First, we consider the ouzo effect, where the mixture forms very stable metastable micro‐emulsions, showing that this process can be generalized, leading to a reverse ouzo effect, where a modifier is added in large quantities. The second retardation technique consists of using very viscous solvents. We found that, in agreement with the predictions of the phase field model, the growth rate of the nuclei during the initial stage of phase separation does not depend on viscosity, while, on the other hand, when the size of the nuclei exceed their capillary length, gravitational effects become relevant and the settling time is proportional to the viscosity of the continuous phase. © 2018 American Institute of Chemical Engineers AIChE J, 64: 4047–4052, 2018     

Co-precipitation synthesis of Nd:YAG nano-powders: the effect of Nd dopant addition with thermal treatment

Nanopowders of Yttrium Aluminium Garnet doped with neodymium ions were obtained by the co-precipitation method from the reaction of aluminium, yttrium and neodymium nitrate with ammonia. The amount of neodymium was selected in order to produce samples of nominal stoichiometry Nd_XY_(3–X)Al₅O₁₂ (where X = 0.006, 0.012, 0.024, 0.048, 0.081, 0.096, 0.17, 0.19, 0.38, 0.54, and 0.72, respectively). After washing and drying, the hydroxide precursors were subjected to Thermo-Gravimetry and Differential Thermal Analysis experiments from room temperature up to 1500 °C, which showed the presence of exothermal events accompanying phase transformation phenomena. X-ray diffraction investigations conducted with a high-resolution powder diffractometer on the specimens arrested at selected temperature of the thermograms, evidenced the amorphous-to-crystalline transformation phenomena leading to the garnet phase as the main product. On increasing the concentration of Nd, the presence of the monoclinic Y₄Al₂O₉ phase was also detected together with a variable amount of a metastable hexagonal YAlO₃ phase. Precise determination of the cubic garnet lattice parameters as a function of the neodymium content according to the Rietveld method shows a change from the value of 12.016 (±2) Å when X = 0 up to 12.128 (±2) Å for X = 0.720 with two distinctive regimes of increase. The line broadening analysis of X-ray profiles after correction for instrumental factors indicates that the average crystallite size is in the range 50–80 nm. Field-Emission Gun-Scanning Electron Microscopy observations showed the presence of aggregation features in the powders with a rounded morphology and a relatively uniform and narrow particle size distribution, with the average size figures in substantial agreement with the diffraction analyses.     

Trends in microbial control techniques for poultry products

Fresh poultry meat and poultry products are highly perishable foods and high potential sources of human infection due to the presence of several foodborne pathogens. Focusing on the microbial control of poultry products, the food industry generally implements numerous preventive measures based on the Hazard Analysis and Critical Control Points (HACCP) food safety management system certification together with technological steps, such as refrigeration coupled to modified atmosphere packaging that are able to control identified potential microbial hazards during food processing. However, in recent years, to meet the demand of consumers for minimally processed, high-quality, and additive-free foods, technologies are emerging associated with nonthermal microbial inactivation, such as high hydrostatic pressure, irradiation, and natural alternatives, such as biopreservation or the incorporation of natural preservatives in packaging materials. These technologies are discussed throughout this article, emphasizing their pros and cons regarding the control of poultry microbiota and their effects on poultry sensory properties. The discussion for each of the preservation techniques mentioned will be provided with as much detail as the data and studies provided in the literature for poultry meat and products allow. These new approaches, on their own, have proved to be effective against a wide range of microorganisms in poultry meat. However, since some of these emergent technologies still do not have full consumer's acceptability and, taking into consideration the hurdle technology concept for poultry processing, it is suggested that they will be used as combined treatments or, more frequently, in combination with modified atmosphere packaging.     

Bioisosteric Modification of To042: Synthesis and Evaluation of Promising Use-Dependent Inhibitors of Voltage-Gated Sodium Channels

Three analogues of To042, a tocainide-related lead compound recently reported for the treatment of myotonia, were synthesized and evaluated in vitro as skeletal muscle sodium channel blockers possibly endowed with enhanced use-dependent behavior. Patch-clamp experiments on hNav1.4 expressed in HEK293 cells showed that N-[(naphthalen-1-yl)methyl]-4-[(2,6-dimethyl)phenoxy]butan-2-amine, the aryloxyalkyl bioisostere of To042, exerted a higher use-dependent block than To042 thus being able to preferentially block the channels in over-excited membranes while preserving healthy tissue function. It also showed the lowest active transport across BBB according to the results of P-glycoprotein (P-gp) interacting activity evaluation and the highest cytoprotective effect on HeLa cells. Quantum mechanical calculations and dockings gave insights on the most probable conformation of the aryloxyalkyl bioisostere of To042 in solution and the target residues involved in the binding, respectively. Both approaches indicated the conformations that might be adopted in both the unbound and bound state of the ligand. Overall, N-[(naphthalen-1-yl)methyl]-4-[(2,6-dimethyl)phenoxy]butan-2-amine exhibits an interesting toxico-pharmacological profile and deserves further investigation.     

Integrated Genomics Identifies miR-181/TFAM Pathway as a Critical Driver of Drug Resistance in Melanoma

MicroRNAs (miRNAs) are attractive therapeutic targets and promising candidates as molecular biomarkers for various therapy-resistant tumors. However, the association between miRNAs and drug resistance in melanoma remains to be elucidated. We used an integrative genomic analysis to comprehensively study the miRNA expression profiles of drug-resistant melanoma patients and cell lines. MicroRNA-181a and -181b (miR181a/b) were identified as the most significantly down-regulated miRNAs in resistant melanoma patients and cell lines. Re-establishment of miR-181a/b expression reverses the resistance of melanoma cells to the BRAF inhibitor dabrafenib. Introduction of miR-181 mimics markedly decreases the expression of TFAM in A375 melanoma cells resistant to BRAF inhibitors. Furthermore, melanoma growth was inhibited in A375 and M14 resistant melanoma cells transfected with miR-181a/b mimics, while miR-181a/b depletion enhanced resistance in sensitive cell lines. Collectively, our study demonstrated that miR-181a/b could reverse the resistance to BRAF inhibitors in dabrafenib resistant melanoma cell lines. In addition, miR-181a and -181b are strongly down-regulated in tumor samples from patients before and after the development of resistance to targeted therapies. Finally, melanoma tissues with high miR-181a and -181b expression presented favorable outcomes in terms of Progression Free Survival, suggesting that miR-181 is a clinically relevant candidate for therapeutic development or biomarker-based therapy selection.     

Analysis of powered two-wheeler crashes in Italy by classification trees and rules discovery

Aim of the study was the analysis of powered two-wheeler (PTW) crashes in Italy in order to detect interdependence as well as dissimilarities among crash characteristics and provide insights for the development of safety improvement strategies focused on PTWs. At this aim, data mining techniques were used to analyze the data relative to the 254,575 crashes involving PTWs occurred in Italy in the period 2006–2008.     

Yarn periodical errors determination using three signal processing approaches

This paper presents a study undertaken to identify the type and location of yarn periodical errors using three different signal processing approaches based on FFT – Fast Fourier Transform, FWHT – Fast Walsh–Hadamard Transform and FDFI – Fast Impulse Frequency Determination. Available commercial equipment is based exclusively on an FFT approach which is unable to clearly detect all types of periodical yarn errors, particularly impulse errors. The theoretical basis of each the three signal processing techniques is described. Their performance when applied to several simulated errors, namely, pulse errors and impulse errors is analyzed in detail. Finally, the three different techniques? ability to successfully characterize errors in actual data taken from real textile yarns with known sinusoidal errors is explored and commented upon.