Gas sensor properties of zno nanorods grown by chemical bath deposition

The present work shows a study about the growing of ZnO nanorods by chemical bath deposition (CBD) and its application as gas sensor. It was prepared ZnO nanorods and Au decorated ZnO nanorods and the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and gas sensing response measurements. The results obtained by XRD show the growth of ZnO phase. It was possible to observe the formation of uniform dense well-aligned ZnO nanorods. The results obtained also revealed that Ag nanoparticles have decorated the surface of ZnO nanorods successfully. Au nanoparticles with diameter of a few nanometers were distributed over the ZnO surface nanorods. The gas sensing response measurements showed a behavior of n type semiconductor. Furthermore, the Au-functionalized ZnO nanorods gas sensors showed a considerably enhanced response at 250 and 300 °C.

Construção e caracterização de células solares de filmes finos de CdS e CdTe

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Preparação e caracterização de semicondutores de PbS e 'B IND. I 'IND. 2' 'S IND. 3' obtidos pelo método de deposição em banho químico

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Síntese de nanofios de óxidos semicondutores para aplicações em dispositivos ópticos e eletrônicos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Eletrodos nanoestruturados de 'TI' 'O IND.2' aplicados na degradação fotoeletrocatalítica de aminas aromáticas e desenvolvimento de dispositivo fotovoltaico 'TI 'O IND.2' / 'SB IND.2' 'S IND.3' / 'P3' 'HT'

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Enhanced photoabsorption properties of composites of Ti/TiO2 nanotubes decorated by Sb2S3 and improvement of degradation of hair dye

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Flexural strength of acrylic resin repairs processed by different methods: water bath, microwave energy and chemical polymerization

Denture fractures are common in daily practice, causing inconvenience to the patient and to the dentists. Denture repairs should have adequate strength, dimensional stability and color match, and should be easily and quickly performed as well as relatively inexpensive. Objective: The aim of this study was to evaluate the flexural strength of acrylic resin repairs processed by different methods: warm water-bath, microwave energy, and chemical polymerization. Material and methods: Sixty rectangular specimens (31x10x2.5 mm) were made with warm water-bath acrylic resin (Lucitone 550) and grouped (15 specimens per group) according to the resin type used to make repair procedure: 1) specimens of warm water-bath resin (Lucitone 550) without repair (control group); 2) specimens of warm water-bath resin repaired with warm water-bath; 3) specimens of warm water-bath resin repaired with microwave resin (Acron MC); 4) specimens of warm water-bath resin repaired with autopolymerized acrylic resin (Simplex). Flexural strength was measured with the three-point bending in a universal testing machine (MTS 810 Material Test System) with load cell of 100 kgf under constant speed of 5 mm/min. Data were analyzed statistically by Kruskal-Wallis test (p<0.05). Results: The control group showed the best result (156.04 +/- 1.82 MPa). Significant differences were found among repaired specimens and the results were decreasing as follows: group 3 (43.02 +/- 2.25 MPa), group 2 (36.21 +/- 1.20 MPa) and group 4 (6.74 +/- 0.85 MPa). Conclusion: All repaired specimens demonstrated lower flexural strength than the control group. Repairs with autopolymerized acrylic resin showed the lowest flexural strength.

Effect of tartrate content on aging and deposition condition of copper-tin electrodeposits from a non-cyanide acid bath

The effect of the presence of tartrate additive on the chemical stability of a Cu-Sn acid bath was evaluated. It was observed that this additive hinders decomposition of the Cu/Sn deposition bath with storage time, since the decrease in electrochemical efficiency was attenuated. In addition, it was observed that optimal galvanostatic deposition with or without tartrate occurs at approximately 11 mA cm(-2). However, in the presence of tartrate the deposition charge was lower, leading to lower energy consumption. SEM analysis showed that the tartrate added to the plating bath caused a marked change in the morphology of the Cu/Sn films obtained gal vanostatic ally. (C) 2002 Elsevier B.V. B.V. All rights reserved.

The generator coordinate method for a reaction coordinate coupled to a harmonic oscillator bath

This paper investigates the usefulness of the generator coordinate method (GCM) for treating the dynamics of a reaction coordinate coupled to a bath of harmonic degrees of freedom. Models for the unimolecular dissociation and isomerization process (proton transfer) are analyzed. The GCM results, presented in analytical form, provide a very good description and are compared to other methods Like the basis set method and multiconfiguration time dependent self-consistent field. (C) 1998 American Institute of Physics. [S0021-9606(98)50934-8].

Anthracnose control and mango quality (Mangifera indica L.) cv. van dyke after hydrothermal and chemical treatment

Anthracnose causes severe damage to the mango skin. Therefore, there is need to do the post-harvest phytosanitary treatment of the fruits through soaking in fungicide solution, which associated with the hydrothermal treatment has resulted into improved benefits. The present work has aimed at studying anthracnose control and post-harvest quality of mangoes (Mangifera indica L.), cv. Van Dyke after hydrothermal treatment associated with chemical through the physical, physicochemical, chemical and phytopathologic analyses. The mangoes coming from the commercial orchard of the town of Jana ba-MG, of the 2000 crop, were harvested at the commercial maturation stage. After selection according to color uniformity, size and absence of mechanic and physiologic injuries, they were shipped in plastic boxes to the EPAMIG - CTNM - Nova Porteirinha - MG, fruit post-harvest laboratory, where the samples were submitted to the hydrothermal treatment in cold bath in solution containing the fungicides Thiabendazole (Tecto 400 mL/100L), Proclaraz (Sportak 10L/100L) and Imazalil (Magnate 200mL/100L). After air-drying, the fruits were packed in plastic trays and stored at room temperature (25 +/- 2 degrees C and RH 70%) for a 12-day period and evaluated as to the intrinsic quality characteristics every 4 days. The experiment was conducted a completely randomized with 8 treatments, 4 replicates and experimental unit consisting of 4 fruits. The variations of pH, total soluble solids, total titrable acidity and total soluble sugars have not endangered the organoleptic characteristics of mangoes cv. Van Dyke stored under room temperature (25 +/- 2 degrees C and RH 70%) till 8 days' storage. The association of the hydrothermal treatment with the chemical was efficient in fruit anthracnose control for till 12 days' storage. The fungicide Prochloraz (Sportak 110 mL/100L), associated with the hydrothermal treatment, completely inhibited the appearance of anthracnose symptoms.