Electrochemical reduction of disperse orange 1 textile dye at a boron-doped diamond electrode

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

The Fabrication and Characterization of a Nickel Nanoparticle Modified Boron Doped Diamond Electrode for Electrocatalysis of Primary Alcohol Oxidation

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

Detection of DNA Nucleotides on Pretreated Boron Doped Diamond Electrodes

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

The Determination of Methanol Using an Electrolytically Fabricated Nickel Microparticle Modified Boron Doped Diamond Electrode

A nickel modified boron doped diamond (Ni-BDD) electrode and nickel foil electrode were used in the determination of methanol in alkaline solutions. The Ni-BDD electrode was electrodeposited from a 1 mM Ni(NO(3))(2) solution (pH 5), followed by repeat cycling in KOH. Subsequent analysis utilised the Ni(OH)(2)/NiOOH redox couple to electrocatalyse the oxidation of methanol. Methanol was determined to limits of 0.3 mM with a sensitivity of 110 nA/mM at the Ni-BDD electrode. The foil electrode was less sensitive achieving a limit of 1.6 mM and sensitivity of 27 nA/mM. SEM analysis of the electrodes found the Ni-BDD to be modified by a quasi-random microparticle array.

Interaction of Organophosphorus Pesticides with DNA Nucleotides on a Boron-Doped Diamond Electrode

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

Transport properties of polycrystalline boron doped diamond

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Detection of several carbohydrates using boron-doped diamond electrodes modified with nickel hydroxide nanoparticles

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

Electron field emission from boron doped microcrystalline diamond

Field emission properties of hot filament chemical vapor deposited boron doped polycrystalline diamond have been studied. Doping level (N-B) of different samples has been varied by the B/C concentration in the gas feed during the growth process and doping saturation has been observed for high B/C ratios. Threshold field (E-th) for electron emission as function of B/C concentration has been measured, and the influences of grain boundaries, doping level and surface morphology on field emission properties have been investigated. Carrier transport through conductive grains and local emission properties of surface sites have been figured out to be two independent limiting effects in respect of field emission. Emitter current densities of 500 nA cm(-2) were obtained using electric fields less than 8 V/mu m. (c) 2007 Elsevier B.V. All rights reserved.

Determination of Total Nitrosamines in Vegetables Cultivated Organic and Conventional Using Diamond Electrode

Vegetables were analyzed for total N-nitrosamines (NAs) and the influence of disinfection processes was assessed. Differences in NAs found in cabbage, spinach, and broccoli were determined by square wave voltammetry using a boron-doped diamond electrode. Analysis of samples showed that all samples contained detectable levels of NAs but the results indicated that organic contained less than conventionally grown products. The sum of the total NAs was higher in the cabbage samples, ranging between 2.8-3.1 ppb and lower in broccoli samples at 0.2-1.1 ppb. The method described is simple, rapid, selective, and sensitive. The results suggested that the disinfection process affects the level of NAs, in this manner affecting the level of human exposure to NAs. © 2012 Springer Science+Business Media New York.

Enhanced photoelectrocatalytic degradation of an acid dye with boron-doped TiO2 nanotube anodes

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

Nanoelectrocatalytic oxidation of lactic acid using nickel nanoparticles

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

Desenvolvimento de detector eletroquímico para cromatografia líquida de alta eficiência baseado em um eletrodo modificado com nanopartículas metálicas para determinação de ácidos carboxílicos em vinhaça de cana-de-açúcar

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

The influence of hydrogen plasma pre-treatment on the structure of BDND electrode surface applied for phenol detection

The surface properties of boron-doped nanocrystalline diamond films treated with H(2) plasma was investigated in regard to their electrochemical response for phenol oxidation. The surface of these films is relatively flat formed by crystallites with sizes of about 40 nm. X-ray photoelectron spectroscopy analyses showed that electrode surface has a high amount of C-H bonds. This behavior is in agreement with Mott-Schottky plot measurements concerning the flat band potential that presented a value as expected for hydrogenated diamond surface. This electrode presented the phenol detection limit of 0.08 mg L(-1) for low phenol concentrations from 40 to 250 mu mol L(-1).

Effectiveness of Screw Surface Coating on the Stability of Zirconia Abutments After Cyclic Loading

Purpose: Different surface treatments have been developed in attempts to prevent the loosening of abutment screws. The aim of the current study was to compare the effectiveness of titanium alloy screws with tungsten-doped diamond-like carbon (W-DLC) coating and uncoated screws in providing stability to zirconia (ZrO2) ceramic abutments after cyclic loading. Materials and Methods: Twenty prefabricated ZrO2 ceramic abutments on their respective external-hex implants were divided into two groups of equal size according to the type of screw used: uncoated titanium alloy screw (Ti) or titanium alloy screw with W-DLC coating (W-DLC/Ti). The removal torque value (preload) of the abutment screw was measured before and after loading. Cyclic loading between 11 and 211 N was applied at an angle of 30 degrees to the long axis of the implants at a frequency of 15 Hz. A target of 0.5 x 10(6) cycles was defined. Group means were calculated and compared using analysis of variance and the F test (alpha=.05). Results: Before cyclic loading, the preload for Ti screws was significantly higher than that for W-DLC/Ti screws (P=.021). After cyclic loading, there was no significant difference between them (P=.499). Conclusions: Under the studied conditions, it can be concluded that, after cyclic loading, both abutment screws presented a significant reduction in the mean retained preload and similar effectiveness in maintaining preload. INT J ORAL MAXILLOFAC IMPLANTS 2012;27:1061-1067

Undoped and calcium doped borate glass system for thermoluminescent dosimeter

Borate glasses present an absorption coefficient very close to that of human tissue. This fact makes some borates ideal materials to develop medical and environmental dosimeters. Glass compositions with calcium tetraborate (CaB4O7) and calcium metaborate (CaB2O4), such as the xCaB(4)O(7) - (100-x)CaB2O4 System (0 <= x <= 100 wt%) were obtained by the traditional melting/quenching method. A phenomenon widely known as the 'boron anomaly' was observed in our thermal analysis measurements, as indicated by the increase of T, and the appearance of a maximum value in the composition with 40 wt% of CaB2O4. The Dy doped and Li co-doped 80CaB(4)O(7)-20CaB(2)O(4) (Wt%) glass samples were studied by the thermoluminescence technique. The addition of Dy improved the signal sensitivity in about three times with respect to the undoped glass sample. The addition of Li as a co-dopant in this glass caused a shift to a lower temperature of about 20 degrees C in the main glow peak. The structural analysis of the 80CaB(4)O(7)-20CaB(2)O(4) (wt%) undoped and doped samples were studied through infrared absorption. We have noted an increase in the coordination number of the boron atoms from 3 to 4, i.e., the conversion of the BO3 triangular structural units into BO4 tetrahedra. (c) 2006 Elsevier B.V. All rights reserved.