Selection criteria and robust optimization of a traction PM-Assisted Synchronous Reluctance motor

In the coming years, the electrification and the deployment of the electric motors in the urban transports will become a more and more widespread reality. The optimization stage of the electric motors usually does not consider in detail the real driving conditions of the car in which the motor is installed. It follows that the actual motor performance in operating points, particularly as regards the torque ripple and the efficiency, might be worse than expected. A robust solution is a required target. This paper deals with the design and optimization of a high-speed permanent-magnet-assisted synchronous reluctance motor for traction applications, taking into account both city and highway driving cycles. A procedure is employed in order to evaluate the most representative operating points, which have to be considered when a global optimization is required. An analysis of the solution robustness has been performed. Both results and advantages of the adopted methodology are highlighted

The hypoxic transcription factor KlMga2 mediates the response to oxidative stress and influences longevity in the yeast Kluyveromyces lactis

Hypoxia is defined as the decline of oxygen availability, depending on environmental supply and cellular consumption rate. The decrease in O2 results in reduction of available energy in facultative aerobes. The response and/or adaptation to hypoxia and other changing environmental conditions can influence the properties and functions of membranes by modifying lipid composition. In the yeast Kluyveromyces lactis, the KlMga2 gene is a hypoxic regulatory factor for lipid biosynthesis-fatty acids and sterols-and is also involved in glucose signaling, glucose catabolism and is generally important for cellular fitness. In this work we show that, in addition to the above defects, the absence of the KlMGA2 gene caused increased resistance to oxidative stress and extended lifespan of the yeast, associated with increased expression levels of catalase and SOD genes. We propose that KlMga2 might also act as a mediator of the oxidative stress response/adaptation, thus revealing connections among hypoxia, glucose signaling, fatty acid biosynthesis and ROS metabolism in K. lactis

The 'petite negative' yeast Kluyveromyces lactis has a single gene expressing pyruvate decarboxylase activity

We cloned and sequenced the pyruvate decarboxylase (PDC; EC 4.1.1.1) structural gene KlPDCA in the yeast Kluyveromyces lactis and found it to be allelic to the previously isolated rag6 mutation. The putative amino acid sequence of the KlPdcAp appeared to be highly homologous to those of the yeast Pdc proteins identified so far. The disruption of KIPDCA indicated that it is the only PDC structural gene in K. lactis, as evidenced by the lack of PDC activity and ethanol production in the pdcAdelta strains and by the absence of growth on glucose in the presence of respiratory inhibitors. It was observed that expression of the KlPDCA gene is induced by glucose at the transcriptional level. Transcription of the gene was reduced in the ragl, rag2, rag5 and rag8 mutants, which are defective for the low-affinity glucose permease, phosphoglucose isomerase, hexokinase, and a positive regulator of RAG1 expression, respectively

Detection strategies for scalar gravitational waves with interferometers and resonant spheres

We compute the response and the angular pattern function of an interferometer for a scalar component of gravitational radiation in Brans-Dicke theory. We examine the problem of detecting a stochastic background of scalar GWs and compute the scalar overlap reduction function in the correlation between an interferometer and the monopole mode of a resonant sphere. While the correlation between two interferometers is maximized taking them as close as possible, the interferometer-sphere correlation is maximized at a finite value of f*d, where `f' is the resonance frequency of the sphere and `d' the distance between the detectors. This defines an optimal resonance frequency of the sphere as a function of the distance. For the correlation between the Virgo interferometer located near Pisa and a sphere located in Frascati, near Rome, we find an optimal resonance frequency f=590 Hz. We also briefly discuss the difficulties in applying this analysis to the dilaton and moduli fields predicted by string theory.Comment: 26 pages, Latex, 4 Postscript figures. Various minor improvements, misprint in eqs. 42, 127, 138 corrected, references adde

Spin and a Running Radius in RS1

We develop a renormalization group formalism for the compactified Randall-Sundrum scenario wherein the extra-dimensional radius serves as the scaling parameter. Couplings on the hidden brane scale as we move within local effective field theories with varying size of the warped extra dimension. We consider this RG approach applied to U(1) gauge theories and gravity. We use this method to derive a low energy effective theory.Comment: 18 pages, minor changes, references adde

A REPLICABLE OPEN-SOURCE MULTI-CAMERA SYSTEM FOR LOW-COST 4D GLACIER MONITORING

Image-based monitoring has emerged as a prevalent technique for sensing mountain environments. Monoscopic time-lapse cameras, which rely on digital image correlation to quantify glacier motion, have limitations due to the need for a Digital Elevation Model for deriving 3D flow velocity fields. Multi-camera systems overcome this limitation, as they allow for a 3D reconstruction of the scene. This paper presents a replicable low-cost stereoscopic system designed for 4D glacier monitoring. The system consists of independent and autonomous units, built from off-the-shelves components, such as a DSLR camera, an Arduino microcontroller, and a Raspberry Pi Zero, reducing costs compared to pre-built time-lapse cameras. The units are energetically self-sufficient and resistant to harsh alpine conditions. The system was successfully tested for more than a year to monitor the northwest terminus of the Belvedere Glacier (Italian Alps). Daily stereo-pairs acquired were processed with Structure-from-Motion to derive 3D point clouds of the glacier terminus and estimate glacier retreat and ice volume loss. By combining the information about ice volume loss with ablation estimates and ice flow velocity information, e.g., derived from monoscopic-camera time series, a multi-camera system enables a comprehensive understanding of sub-seasonal glacier dynamics

Ni Catalysts Supported Over TiO2, SiO2 and ZrO2 for the Steam Reforming of Glycerol

A 72-year-old man was admitted with one blade of a huge pair of shears in his left thorax. His hemodynamics deteriorated due to life-threatening vascular lesions. An urgent thoracotomy revealed several injuries to the intercostal vessels and left apical inferior lung lobe. The blade tip was stuck in the posterior chest wall, 2 cm adjacent to the descending aorta. The blade was removed, the lung was sutured, and the patient made a good recovery

Ni Catalysts Supported Over TiO2, SiO2 and ZrO2 for the Steam Reforming of Glycerol

Ni-based catalysts supported on TiO2, ZrO2 and SiO2 (in the form of mesoporous Santa Barbara Amorphous 15 (SBA-15) and amorphous dense nanoparticles), were employed in the steam reforming of glycerol. Each sample was prepared by liquid phase synthesis of the support followed by impregnation with the active phase and calcination at 8008C or by direct synthesis through flame pyrolysis. Many techniques have been used to assess the physical chemical properties of both the fresh and spent catalysts, such as atomic absorption, N2 adsorption/desorption, XRD, SEM, TEM, temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), Micro-Raman and FTIR spectroscopy. The samples showed different textural, structural and morphological properties,as well as different reducibility and thermal resistance depending on the preparation method and support. Some of these properties were tightly bound to catalyst performance, in terms of H2 productivity and stability towards coking and sintering. A key parameter was the metal\u2013support interaction, which strongly depended on the preparation procedure. In particular, the stronger the interaction, the more stable the metallic Ni clusters, which in turn lead to a higher catalytic activity and stability. Surface acidity was also taken into account, in which the nature of the acid sites was differentiated (silanols, titanols or Lewis acid sites). The characterisation of the spent catalysts also allowed us to interpret the deactivation process. The formation of multi-walled nanotubes was observed for every sample, though it was only in some cases that this led to severe deactivatio

Synthetic Hydrotalcites as suitable Co-based catalysts for Fischer-Tropsch Process

Nowadays it is imperative to develop economical and energy-efficient processes for the sustainable production of alternative fuels and chemicals. Fischer Tropsch synthesis (FT) is a well-established industrial process whereby these objectives can be achieved using syngas (mixture of H2, CO, CO2) as raw material. Syngas can be manufactured from CH4, coal or, as a new tendency, frombiomass. FT synthesis usually requires catalysts based on cobalt or iron. The typical products range is from methane to long chain hydrocarbons (waxes) [1]. Cobalt-based catalysts have been used for FT for long time due to their long life-times, high CO conversion and high selectivity to heavy hydrocarbons; they are moreover characterized by low activity towards the water-gas shift, so avoiding the CO2 formation. In this work, layered double or triple hydroxides, also known as synthetic hydrotalcites, are proposed and studied as FT catalysts. The choice of these materials allows to easily prepare solid phases, essentially based on mixed metal oxides, where specific metal atoms are homogeneously dispersed at an atomic level. Hydrotalcites are represented by the empirical formula [M(II)1-xM(III)x(OH)2]x+[An-x/n]x-mH2O where M(II) is a divalent cation such as Co, Mg, Zn, Ni, or Cu, M(III) is a trivalent cation such as Al, Cr, Fe or Ga; An- is an anion of charge n and m the molar amounts of co-intercalated water [2]. When calcined at proper temperatures, the random distribution of cations, characteristic of the hydroxide phase, is maintained in the resulting mixed oxide. Hydrotalcite based materials have been recently reported as good catalysts for several processes in the energy field, such as hydrogen production by steam reforming of methanol and ethanol, photocatalytic water splitting and so on [3-5]. A series a Co-Zn-Al hydrotalcites, with increasing Co contents was synthesized and characterized. Preliminary tests on their catalytic activity in the FT process resulted in a satisfactory outcome

Explicit de Sitter Flux Vacua for Global String Models with Chiral Matter

We address the open question of performing an explicit stabilisation of all closed string moduli (including dilaton, complex structure and Kaehler moduli) in fluxed type IIB Calabi-Yau compactifications with chiral matter. Using toric geometry we construct Calabi-Yau manifolds with del Pezzo singularities. D-branes located at such singularities can support the Standard Model gauge group and matter content. In order to control complex structure moduli stabilisation we consider Calabi-Yau manifolds which exhibit a discrete symmetry that reduces the effective number of complex structure moduli. We calculate the corresponding periods in the symplectic basis of invariant three-cycles and find explicit flux vacua for concrete examples. We compute the values of the flux superpotential and the string coupling at these vacua. Starting from these explicit complex structure solutions, we obtain AdS and dS minima where the Kaehler moduli are stabilised by a mixture of D-terms, non-perturbative and perturbative alpha'-corrections as in the LARGE Volume Scenario. In the considered example the visible sector lives at a dP_6 singularity which can be higgsed to the phenomenologically interesting class of models at the dP_3 singularity.Comment: 49 pages, 5 figures; v2: references adde