Search results for " TiO"

Implicit differentiation for fast hyperparameter selection in non-smooth convex learning

2022

International audience; Finding the optimal hyperparameters of a model can be cast as a bilevel optimization problem, typically solved using zero-order techniques. In this work we study first-order methods when the inner optimization problem is convex but non-smooth. We show that the forward-mode differentiation of proximal gradient descent and proximal coordinate descent yield sequences of Jacobians converging toward the exact Jacobian. Using implicit differentiation, we show it is possible to leverage the non-smoothness of the inner problem to speed up the computation. Finally, we provide a bound on the error made on the hypergradient when the inner optimization problem is solved approxim…

Surface characterization of metal ions loaded TiO2 photocatalysts: structure-activity relationship

2004

Transition metal loaded TiO2 powders were characterised and tested for the photodegradation of some organic acids. Both Lewis and Brønsted surface acid sites were present in the samples containing large amounts of Mo, V and W. The Brønsted sites are associated to the presence of the transition metals as they do not exist in the unloaded support, and in particular to the presence of these metals in high oxidation states. The trend of the pzc values of the various powders matches rather well both with the surface acidity of the samples experimentally determined by NH3 adsorption and with a scale of acidity/basicity for bulk binary oxides. XPS investigation indicates that only the presence of …

Photocatalytic properties of TiO2 doped with metal and non metal species

2009

Ossidazione del 2-Propanolo Fotocatalizzata da Sistemi Ibridi Bis-Ftalocianina Lantanide-TiO2:Confronto tra Processi Gas-Solido e Liquido-Solido

2008

Blue light activated photodegradation of biomacromolecules by N-doped titanium dioxide in a chitosan hydrogel matrix

2023

The use of photocatalysis activated by titanium dioxide nanostructured materials is a promising solution for many biomedical applications ranging from drug-free antibacterial to anticancer therapies, as well as for innovative hydrogel-supported phototherapies. This makes the effects of photocatalysis on the structure of biomolecules of a great relevance in order to define the applicability of photocatalytic materials in the biomedical fields. In this work, the effects of nitrogen-doped titanium dioxide (N-TiO2) dispersed in a biocompatible chitosan/PEG hydrogel on myoglobin and bovine serum albumin as target model proteins were investigated. The efficiency of this composite biocompatible ma…

Photocatalytic glucose conversion to produce hydrogen in the presence of TiO2 based materials.

2015

In the present research commercial anatase (BDH) and anatase/rutile (P25) and home prepared anatase (HPA), rutile (HPR) and brookite (HPB) TiO2 polymorphs and have been used as supports for the deposition of metallic Pt. The Pt-TiO2 samples have been tested in the glucose conversion under anaerobic conditions. The presence of Pt resulted essential for the production of H2 and the home prepared samples resulted more active than the commercial ones.

Inverse opal TiO2 photocatalytsts for environmental applications

2017

This work aims to study the influence that different doping agents can have on the chemico-physical properties of TiO2 synthesized with the task to obtain an ordered porous material with an inverse opal structure and to evaluate the photocatalytic performance of these systems in the degradation of a model dye molecule (Rhodamine B, RhB) in water under Visible light irradiation.

Lanthanide Diphthalocyanine – Photosensitizers in TiO2 Hybrid Catalytic Systems: Green Chance for The Nature

2008

From Global Initiative for Chronic Obstructive Lung Disease (GOLD) Guidelines to Current Clinical Practice

2006

Background: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines have been promulgated to improve the management of chronic obstructive pulmonary disorder (COPD). Objective: To evaluate the extent to which the current therapeutic approach to COPD conforms to GOLD guidelines. Methods: This was a multicentre observational study of elderly COPD patients enrolled for acute care in general medicine or geriatric wards in tertiary hospitals in Italy in April 2002. Our series consisted of 471 patients >64 years of age consecutively admitted for acute exacerbations of COPD to wards participating in the study. Data describing drugs used prior to exacerbation and prescribed at …

Generic Advertising, Brand Advertising and Price Competition: An Analysis of Free-Riding Effects and Coordination Mechanisms

2010

The main purpose of generic advertising is to enlarge the total market demand rather than capturing further slices from competitors. Several studies point out emergence of free-riding behavior under independent contribution and suggest use of coordination mechanism. However, existing literature does not shed light on the conditions under which generic advertising can be detrimental (beneficial) to stronger firms weakening (strengthening) their competitive advantage. Also, under a setting including both price and brand advertising competition, coordination in generic advertising has not been unraveled. In order to deal with such issues, we consider a one-stage duopoly game in which two firms…