Reduction of boron penetration through thin silicon oxide with a nitrogen doped silicon layer

This paper deals with the development of the disilane Si₂H₆ gaseous source for gate technology and more precisely, reports on the use of nitrogen doped silicon (NIDOS) deposited from disilane and ammonia for the realisation of polycrystalline gate. Boron diffusivity into the NIDOS films is studied thanks to SIMS experiments, and results are extended to the fabrication of P⁺-poly-Si/NIDOS/SiO₂/Si capacitive structures. Electrical characterisations evidenced finally the influence of boron and nitrogen atoms on the electrical properties of PMOS devices.     

Flow injection analysis with amperometric detection for iodide determination as a tracer in seawater reservoirs

In this study, an electrochemical method was developed using flow injection analysis and amperometric detection with screen-printed electrodes for iodide determination as a tracer in seawater reservoirs. The amperometric method resulted in a good linear correlation coefficient (r = 0.9966) with a linear response over a concentration range of 1–10 mg L⁻¹, a limit of detection of 0.2 mg L⁻¹ and a quantification of 0.6 mg L⁻¹. In addition, the method has been shown to be precise, linear and homoscedastic. The recovery for the amperometric method was 100 ± 3 %, and the recovery for the produced water samples fortified with iodide was 102 ± 2 %. The amperometric method did not show interference from other anions. Thus, the proposed method is promising for analysing the iodide content of seawater reservoir samples with simple and inexpensive methodologies compared with ion chromatography techniques.     

Morphoquantitative evaluation of the duodenal myenteric neuronal population in rats fed with hypoproteic ration.

The purpose of this work was to analyze the morphoquantitative behavior of the neurons of the myenteric plexus, as well as the morphometry of the duodenal wall, in adult rats fed with normoproteic (22%) and hypoproteic (8%) rations, killed at the age of 345 days. For neuronal assessments duodenal whole-mounts stained with the Giemsa method were used, and for the evaluation of the duodenal wall routine histological processing and staining with Hematoxilin-Eosin were employed. The means of the number of neurons in 80 microscopic fields (12.72 mm2) and of the size of the neuronal cell bodies did not reveal statistically significant differences between the groups, but there was a greater incidence of large neurons in the protein restriction group (RP). The duodenum was markedly smaller in the RP group and, although there was no difference in the thickness of its wall, the mucosa was larger and the muscular layer was smaller in group RP. It was concluded that the neuronal and non-neuronal components of the duodenum adjust themselves to the nutritional condition, assuring the maintenance of their functions.     

Microstructural Evolution of Titanium Carbide–Chromium Carbide (TiC–Cr3C2) Composites Produced via Combustion Synthesis

A microstructural analysis of compounds produced by combustion synthesis coupled with hot pressing, for reactions between titanium, chromium, and carbon, was conducted. The reactions were aimed to produce composites of Cr₃C₂ and TiC at three different volume fractions of each carbide (25/75, 50/50, and 75/25). Large amounts of chromium and carbon were found to be in solution in the B1 rock-salt structure of TiC. The materials with 25 and 50 vol% of Cr₃C₂ consisted of 100% (Ti,Cr)C_ss solid solution, while the composition with 75 vol% Cr₃C₂ was formed by Cr₃C₂+ (Ti,Cr)C_ss. Some precipitation of Cr₃C₂ was achieved by annealing, but a minimum of 20 wt% was always in solution. The 50 vol% Cr₃C₂–50 vol% TiC composition was the most affected by the heat treatments. Discontinuous and general precipitation were observed, depending on the annealing conditions. A TTT-type diagram was plotted for this material.     

Learning patterns in ambient intelligence environments: a survey

It is essential for environments that aim at helping people in their daily life that they have some sort of Ambient Intelligence. Learning the preferences and habits of users then becomes an important step in allowing a system to provide such personalized services. Thus far, the exploration of these issues by the scientific community has not been extensive, but interest in the area is growing. Ambient Intelligence environments have special characteristics that have to be taken into account during the learning process. We identify these characteristics and use them to highlight the strengths and weaknesses of developments so far, providing direction to encourage further development in this specific area of Ambient Intelligence.     

Pineal transplantation to the brain of pinealectomized lizards: Effects of circadian rhythms of locomotor activity.

Pinealectomized lizards (Podarcis sicula) whose locomotor rhythms were recorded in constant temperature (29°C) and darkness were subdivided into 2 groups of hosts: Each belonging to the 1st group (experimentals) received from a donor a pineal gland, and each belonging to the 2nd one (controls) received a piece of cerebellum. Pineal transplantation induced drastic changes in the free-running period (τ) of locomotor rhythms, which were significantly greater than the τ changes induced by cerebellum transplantation. Either application or removal of melatonin implants left the locomotor rhythms of the controls completely undisturbed, showing that in absence of melatonin rhythms (pinealectomy alone abolishes blood-borne melatonin rhythms) melatonin implants are ineffective. Melatonin rhythms, however, had to be present in the experimentals, because the circadian system reacts to melatonin implants by changing τ (as if melatonin rhythms had been suppressed) and to removal of the implants by again changing τ (as if melatonin rhythms had been restored). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preliminary experiments in speaker verification using time-dependent largest Lyapunov exponents

The characterization of a speech signal using non-linear dynamical features has been the focus of intense research lately. In this work, the results obtained with time-dependent largest Lyapunov exponents (TDLEs) in a text-dependent speaker verification task are reported. The baseline system used Gaussian mixture models (GMMs), obtained from the adaptation of a universal background model (UBM), for the speaker voice models. Sixteen cepstral and 16 delta cepstral features were used in the experiments, and it is shown how the addition of TDLEs can improve the system’s accuracy. Cepstral mean subtraction was applied to all features in the tests for channel equalization, and silence frames were discarded. The corpus used, obtained from a subset of the Center for Spoken Language Understanding (CSLU) Speaker Recognition corpus, consisted of telephone speech from 91 different speakers.     

Classification System of Raman Spectra using Cluster Analysis to Diagnose Coronary Artery Lesions

Abstract

The traditional methods employed to detect atherosclerotic lesions allow for the identification of lesions; however, they do not provide specific characterization of the lesion's biochemistry. Currently, Raman spectroscopy techniques are widely used as a characterization method for unknown substances, which makes this technique very important for detecting atherosclerotic lesions. The spectral interpretation is based on the analysis of frequency peaks present in the signal; however, spectra obtained from the same substance can show peaks slightly different and these differences make difficult the creation of an automatic method for spectral signal analysis. This paper presents a signal analysis method based on a clustering technique that allows for the classification of spectra as well as the inference of a diagnosis about the arterial wall condition. The objective is to develop a computational tool that is able to create clusters of spectra according to the arterial wall state and, after data collection, to allow for the classification of a specific spectrum into its correct cluster.     

The use of goal-oriented strategies in the building of water governance in Brazil

Water policy in Brazil has delivered few positive outcomes in terms of the sustainable use of water resources, in spite of real progress in the consolidation of a democratic water governance system over the past decades. There are many reasons for this, most of them related to unsuccessful attempts to consolidate integrated water resources management practices. Water managers have a critical decision to make in the next years: to strengthen the existing decentralized and participatory water governance system, using innovative approaches to promote integrated water resources management; or to replace it with another, more centralized institutional model focusing on state actors.     

Effects of exposition to polluted environments on blood cells of the fish Prochilodus lineatus

In this study, we investigated the effects of contaminated water on the blood parameters of the fish Prochilodus lineatus exposed during 7 and 20 days. Blood was collected with heparinized syringes, and blood smears were prepared and stained with Leishman stain. Slides were examined and photographed using a Leica light microscope. Total white blood cell counts and differential counts of thrombocytes and leukocytes were obtained for statistical analysis. The group exposed to water samples from Lago Azul exhibited an increase in the number of leukocytes and in the total number of white blood cells, suggesting that the chemical contaminants in this environment were acting similarly to antigens in this fish species, causing the proliferation of defense cells. In the group exposed to detergent during 20 days, the number of thrombocytes decreased. These results suggest that the variations in the number of leukocytes were indicators of environmental pollution and that biodegradable detergents may, after a certain time of exposure, affect vital functions in fish, such as coagulation and prevention of infections, which directly involves thrombocytes.