Search results for " Merit"

Enhanced thermoelectric performance in the p-type half-Heusler (Ti/Zr/Hf)CoSb0.8Sn0.2 system via phase separation

2014

A novel approach for optimization of the thermoelectric properties of p-type Heusler compounds with a C1b structure was investigated. A successful recipe for achieving intrinsic phase separation in the n-type material based on the TiNiSn system is isoelectronic partial substitution of Ti with its heavier homologues Zr and Hf. We applied this concept to the p-type system MCoSb0.8Sn0.2 by a systematic investigation of samples with different compositions at the Ti position (M = Ti, Zr, Hf, Ti0.5Zr0.5, Zr0.5Hf0.5, and Ti0.5Hf0.5). We thus achieved an approximately 40% reduction of the thermal conductivity and a maximum figure of merit ZT of 0.9 at 700 °C. This is a 80% improvement in peak ZT fr…

Scaling the Analytical Information Given by Several Types of Colorimetric and Spectroscopic Instruments Including Smartphones: Rules for Their Use an…

2021

The analytical information given by different types of instruments was scaled in order to establish suitably the figures of merit of a given methodology based on color measurements. Different lab and portable instruments, including smartphones with and without a miniaturized spectrophotometer accessory, have been tested. In order to obtain broad information and using objective criteria, these instruments have been compared from (1) the analytical point of view, considering mainly the detection limit (limits of detection [LODs]), selectivity, accuracy and intra- and interday precision, size, components, and costs; and (2) the environmental point of view, based on their footprint as kilograms…

(S)legati (d)al lavoro. Adulti giovani e occupazione tra ricomposizione e frammentazione sociale

2005

"Esse Malo Quam videri". Sangre y mérito en la orden de Malta a través de la literatura de ficción (Italia, siglos XVI-XVII)

2015

Textos de comunicaciones defendidas en la XIII Reunión Científica de la Fundación Española de Historia Moderna, previa evaluación ciega por pares.

Quid meruere nepotes. Responsabilità e merito nella Pharsalia di Lucano

2017

Il contributo indaga l’epos lucaneo ricostruendo i contesti in cui compaiono nel poema meritum e derivati, immagini che coinvolgono tanto la nozione di merito quanto quella di responsabilità. Si tratta di un’oscillazione ben visibile ed operante all’interno dell’opera, dove tali accezioni tornano con frequenza a scandire tanto le azioni dei protagonisti quanto i severi giudizi del narratore. The paper deals with Lucan’s Pharsalia, reconstructing the contexts in which meritum and derivatives appear, images that both involve the notion of merit as that of responsibility. It is a highly visible and active presence within the poem, where such meanings frequently appear, characterizing both the …

Infrastructura Naturans. Architetture di trasformazione della circonvallazione di Palermo

2022

The article discusses the theoretical system that supports design themes and processes of recycling large urban road infrastructures, referring to an international research that frames them among the sustainable regeneration processes of the contemporary city, and further evoking the project for the transformation of Palermo's ring road that has been elaborated within this research. Witnesses of past urban seasons, these infrastructures are marked by a peculiar morphology that deserves to be maintained, while they must emancipate themselves from asphalt and adapt to new urban mobilities. By hybridizing vegetation and buildings as never before, the longest roadways in our urban contexts may …

Effects of Masking on Open-Circuit Voltage and Fill Factor in Solar Cells

2019

Guidelines for the correct measurement protocol of novel photovoltaic technologies such as perovskites are becoming more frequent in literature. This because, as will be confirmed in this perspective, it is not straightforward to correctly measure the efficiency parameters of these and many other novel solar cells. This is particularly the case for small area research devices which are prone to overestimate the short circuit current density, due to edge effects of various types. To reduce the inaccuracy of current density determination, the common recommended practice is to utilize masks with well‐defined apertures, often smaller than the device active area. Herein we show both experimental…

Towards higher zT in early transition metal oxides: optimizing the charge carrier concentration of the WO3-x compounds

2018

Abstract Thermoelectric devices are believed to play an important role in the energy research for the next decades. Thanks to their low costs coupled with high stability and sustainability, metal oxides are very promising materials even if their efficiencies still need improvements to ensure a wide applicability. Slightly reduced early transition metal oxides show intrinsic defects in the crystal structure which guarantee very low values of the thermal conductivity. The challenge to fulfil the “phonon-glass electron-crystal” concept is to decouple the optimization of the electronic properties from the thermal transport properties. In this contribution we report the optimization of the charg…

Enhanced thermoelectric properties of lightly Nb doped SrTiO3 thin films

2021

Novel thermoelectric materials developed for operation at room temperature must have similar or better performance along with being as ecofriendly as those commercially used, e.g., BiTe, in terms of their toxicity and cost. In this work, we present an in-depth study of the thermoelectric properties of epitaxial Nb-doped strontium titanate (SrTiNbO) thin films as a function of (i) doping concentration, (ii) film thickness and (iii) substrate type. The excellent crystal quality was confirmed by high resolution transmission electron microscopy and X-ray diffraction analysis. The thermoelectric properties were measured by the three-omega method (thermal conductivity) and van der Pauw method (el…

Thermoelectric properties of Sr_3GaSb_3 – a chain-forming Zintl compound

2012

Inspired by the promising thermoelectric properties in the Zintl compounds Ca_3AlSb_3 and Ca_5Al_2Sb_6, we investigate here the closely related compound Sr_3GaSb_3. Although the crystal structure of Sr_3GaSb_3 contains infinite chains of corner-linked tetrahedra, in common with Ca_3AlSb_3 and Ca_5Al_2Sb_6, it has twice as many atoms per unit cell (N = 56). This contributes to the exceptionally low lattice thermal conductivity (κ_L = 0.45 W m^(−1) K^(−1) at 1000 K) observed in Sr_3GaSb_3 samples synthesized for this study by ball milling followed by hot pressing. High temperature transport measurements reveal that Sr_3GaSb_3 is a nondegenerate semiconductor (consistent with Zintl charge-coun…