Search results for " Merit"
showing 10 items of 91 documents
Half-Heusler superlattices as model systems for nanostructured thermoelectrics
2015
The efficiency of thermoelectric materials is directly related to the dimensionless figure of merit , therefore, one of the means to improve ZT is to reduce the thermal conductivity. Our research focuses on half-Heusler superlattices (SLs) and the relationship between the SL period and the thermal conductivity. The cross-plane thermal conductivity of DC-sputtered TiNiSn/HfNiSn SLs was measured by the 3 method at room temperature and a clear reduction of was achieved for all SL periods, in particular for periods smaller than 20 nm. Moreover, the thermal conductivities of TiNiSn and HfNiSn single films display reduced values compared to the literature data for bulk materials. Furthermore, we …
Enhanced acoustic pressure sensors based on coherent perfect absorber-laser effect
2021
Lasing is a well-established field in optics with several applications. Yet, having lasing or huge amplification in other wave systems remains an elusive goal. Here, we utilize the concept of coherent perfect absorber-laser to realize an acoustic analog of laser with a proven amplification of more than 10 4 in terms of the scattered acoustic signal at a frequency of a few kHz. The obtained acoustic laser (or the coherent perfect absorber-laser) is shown to possess extremely high sensitivity and figure of merit with regard to ultra-small variations of the pressure (density and compressibility) and suggests its evident potential to build future acoustic pressure devices such as precise sensor…
Thermoelectric properties of CoTiSb based compounds
2009
Several CoTiSb based compounds were synthesized and investigated on their thermoelectric properties. The aim was to improve the thermoelectric properties of CoTiSb by the systematic substitution of atoms or the introduction of additional Co into the vacant sublattice. The solid solutions Co1+xTiSb, Co1?yCuyTiSb and CoTiSb1?zBiz were synthesized. X-ray diffraction was used to investigate the crystal structure. The resistivity, the Seebeck coefficient and the thermal conductivity were determined for all compounds in the temperature range from 2 to 400?K. The highest figure of merit for each solid solution is presented. We were able to improve the figure of merit by a factor of approximately s…
Computationally efficient dynamical analysis of optically driven injection-locked GaAs FET oscillators
1995
A computer-aided simulation technique for the dynamical analysis of a class of GaAs FET optically-driven injection-locked oscillators (ODILO's) is presented. By combining a measurement-derived nonlinear model of the illuminated transistor with a phasor-domain analysis method, a first-approximation - but phenomenologically complete - differential model of the synchronized oscillator is derived. Since amplitude and phase of waveform evolutions are directly addressed and evaluated in a stroboscopic-time scale, the calculation of the transient response to modulated input signals can be done in a more user-friendly and computationally efficient manner than possible through conventional time-doma…
Optimisation of chromatographic resolution using objective functions including both time and spectral information.
2014
The optimisation of the resolution in high-performance liquid chromatography is traditionally performed attending only to the time information. However, even in the optimal conditions, some peak pairs may remain unresolved. Such incomplete resolution can be still accomplished by deconvolution, which can be carried out with more guarantees of success by including spectral information. In this work, two-way chromatographic objective functions (COFs) that incorporate both time and spectral information were tested, based on the peak purity (analyte peak fraction free of overlapping) and the multivariate selectivity (figure of merit derived from the net analyte signal) concepts. These COFs are s…
El nuevo escenario del orden público en el arbitraje : comentario a la STC de España, Sala Primera, núm. 17/2021, de 15 de febrero.
2021
The Constitutional Court delimits the concept and scope of public order, the requirement to state the grounds and the judicial review within the framework of the action for annulment of arbitral awards. The Constitutional Court rejects the jurisprudential line of the High Court of Justice of Madrid regarding the broadening of the concept of public policy and prevents the review of the merits of the case through the action for annulment.
Recent advances in on-line solid-phase pre-concentration for inductively-coupled plasma techniques for determination of mineral elements
2012
Abstract We provide a critical survey on recent progress in on-line solid-phase pre-concentration for inductively-coupled plasma (ICP)-based techniques for trace-level determination of metals. We highlight some of the useful solid-phase materials suitable for on-line separation and enrichment prior to ICP determination. We discuss different applications of the methods developed along with their analytical figures of merit. Finally, we sketch out future prospects in this field.
Peak deconvolution in one-dimensional chromatography using a two-way data approach.
2002
A deconvolution methodology for overlapped chromatographic signals is proposed. Several single-wavelength chromatograms of binary mixtures, obtained in different runs at diverse concentration ratios of the individual components, were simultaneously processed (multi-batch approach), after being arranged as two-way data. The chromatograms were modelled as linear combinations of forced peak profiles according to a polynomially modified Gaussian equation. The fitting was performed with a previously reported hybrid genetic algorithm with local search, leaving all model parameters free. The approach yielded more accurate solutions than those found when each experimental chromatogram was fitted in…
Computation Cluster Validation in the Big Data Era
2017
Data-driven class discovery, i.e., the inference of cluster structure in a dataset, is a fundamental task in Data Analysis, in particular for the Life Sciences. We provide a tutorial on the most common approaches used for that task, focusing on methodologies for the prediction of the number of clusters in a dataset. Although the methods that we present are general in terms of the data for which they can be used, we offer a case study relevant for Microarray Data Analysis.
Improving thermoelectric performance of TiNiSn by mixing MnNiSb in the half-Heusler structure
2016
The thermoelectric properties of n type semiconductor, TiNiSn is optimized by partial substitution with metallic, MnNiSb in the half Heusler structure. Herein, we study the transport properties and intrinsic phase separation in the system. The Ti1-xMnxNiSn1-xSbx alloys were prepared by arc-melting and were annealed at temperatures obtained from differential thermal analysis and differential scanning calorimetry results. The phases were characterized using powder X-ray diffraction patterns, energy dispersive X-ray spectroscopy, and differential scanning calorimetry. After annealing the majority phase was TiNiSn with some Ni rich sites and the minority phases was majorly Ti6Sn5, Sn, and MnSn2…