Search results for "Lead"

In situ transmission electron microscopy study of electron beam-induced transformations in colloidal cesium lead halide perovskite nanocrystals

2017

An increasing number of studies have recently reported the rapid degradation of hybrid and all-inorganic lead halide perovskite nanocrystals under electron beam irradiation in the transmission electron microscope, with the formation of nanometer size, high contrast particles. The nature of these nanoparticles and the involved transformations in the perovskite nanocrystals are still a matter of debate. Herein, we have studied the effects of high energy (80/200 keV) electron irradiation on colloidal cesium lead bromide (CsPbBr3) nanocrystals with different shapes and sizes, especially 3 nm thick nanosheets, a morphology that facilitated the analysis of the various ongoing processes. Our resul…

The Process of CEO Dismissal: An Exploratory study

2018

The decision to change the CEO is one of the most important decisions of the Board of Directors in a company. This study increases understanding of the process that leads to a Board’s decision to dismiss the CEO under conditions of poor performance, and of the meaning of attributions in CEO dismissal. The role of the Chair of the Board in this process is also explored. An exploratory, empirical study concerning nine CEO dismissal processes is conducted based on open-ended interviews with seven Chairpersons of the Board. The findings shed light on the issues that impact the relationship between poor company performance and CEO dismissal. In particular, the results increase understanding of t…

La chemiometria ed il molecular modeling in ausilio alla scoperta ed all’ottimizzazione di lead compounds

2008

Selective solid phase extraction of a drug lead compound using molecularly imprinted polymers prepared by the target analogue approach

2002

Molecularly imprinted polymers have been evaluated at the sample clean-up stage in the analysis of a drug lead compound. In order to circumvent quantification problems related to bleeding of the template, a structurally related analogue of the latter was used. This was selected based on criteria related to interaction site location, solubility, availability and stability of the analogue. Selection of suitable polymerisation conditions was then made using a small batch format (ca. 50 mg) and rapid assessment of binding in the equilibrium mode. It was found that the amount of template could be greatly reduced compared to the conventional protocol, requiring only 5 μmol of template per gram of…

The impact of Pleurotus ostreatus on organic matter transformation processes.

2012

This study showed the effect of Pleurotus ostreatus on the external organic matter (OM) transformation processes. The kinetics of these changes were determined. The experiment was conducted as 42-day pot experiment done in four combinations (with four replications). The four combinations of different substrates were: (1) organic, (2) composted hay, (3) organic soil + composted hay, (4) organic soil + composted hay + lead. The study results showed that P. ostreatus had the ability to transform external OM as well as metal–organic complexes. These transformations were reflected in the constant rate of characterized changes and correlation coefficients. The study also indicated the direction o…

On lead-scandium tantalate solid solutions with high electrocaloric effect

1992

Abstract The PbSc0,5Ta0,5O3 solutions are found to be a useful material for active elements of microcryogenic devices based on electrocaloric effect. A temperature difference of ΔT = 1. 0-1.8 K at field intensities 20–30 kV/cm in the interval of 210–310 K can be achieved by simultaneous or separate introducing of Sb and Co ions in B-sites of the lattice. The most important contribution to the electrocaloric effect is due to field-induced Fn3m → R3m phase transition in the case of high ordering of B-ions in the perovskite structure ABO3.

Synthesis of Lead Zirconate Antiferroelectric Thin Films by Sol-Gel Processing

2000

A modified methoxyethanol sol-gel process was used for the production of PbZrO3 thin films. The new route uses lead oxide [PbO] instead of lead acetate [Pb(OAc)2]. Through the use of this method it is possible to prepare single-phase perovskite materials with improved properties. Examples are given for PbZrO3 thin layers deposited by the spin coating process on TiO2/Pt/TiO2/SiO2/Si substrates from various sols where lead acetate or lead oxide are used as the starting lead compound. The preferred orientation and the perovskite phase content of the films were studied using X-ray diffraction analysis (XRD). Scanning electron microscopy (SEM) was used for microstructural characterization of the…

Electrochemical Characterization of Corrosion Products in Leaded Bronze Sculptures Considering Ohmic Drop Effects on Tafel Analysis

2015

[EN] The characterization of corrosion products in leaded bronze based on the voltammetry of immobilized particles methodology is described. Voltammetric data, supported by Fourier transform infra-red spectroscopy, field emission scanning electron microscopy-energy dispersive X-ray microanalysis (FESEM-EDX) and scanning electrochemical microscopy (SECM) allow the identification of copper and lead corrosion materials. The mutual influence of such products is modeled upon considering uncompensated ohmic drops in the Tafel analysis of the rising portion of the respective voltammetric signals for their electrochemical reduction.

El empleado como recurso operante en la cocreación de valor: aplicación al ámbito de salud

2023

En el contexto sanitario actual, la investigación de la cocreación de valor desde la perspectiva del marketing ha experimentado un aumento sostenido. Frow et al. (2016) destacan que la atención sanitaria representa un contexto de servicio importante para investigar la cocreación de valor debido al reconocimiento generalizado de la importancia de las actividades colaborativas entre los diversos actores en la obtención de resultados beneficiosos para la salud. Si bien la participación del paciente en el proceso de cocreación de valor ha recibido una considerable atención en la literatura reciente, la cocreación liderada por los empleados está notoriamente ausente. Sin embargo, Palumbo (2016) …

Business schools’ competitive strategies : whose goals, which aims?

2019

Purpose This study reviews the literature on business-school (b-school) competition and competitiveness to extend our understanding of b-schools’ competitive strategies. Design/methodology/approach Both content and network analysis were used in the examination of the scholarly discourse. Findings The analyses distinguish three literature streams. The first concentrates on resources, capabilities and competencies; the second focuses on measures of competitiveness; and the third includes competitive dynamics and strategy discourse. The analysis shows that the conceptions of competitiveness are quite coherent concerning resources, capabilities and competencies. However, in the “measures of com…