Search

Raw material mixtures in compound feeds may increase the risk of contamination with different mycotoxins, and their intake can lead to interactive toxic effects. As a result, there is a growing awareness of the risks posed to human and animal health by the presence of toxins produced by fungi in food and diet. The aim of this study is to assess the impact of the use of a mycotoxin binder (Micotec) on zootechnical performance in broilers. For this purpose, 3000 day-old chicks of the Arbor acres strain originating from the same hatchery were weighed and distributed equally into six groups [one control (C) and five experimental (Exp), as five repetitions receiving the mycotoxin binder Micotec at a dose of 0.1 kg]. All subjects (control and experimental groups) were fed a standard staple food suitable for each phase of rearing. The results showed significant differences between the experimental groups and the control one. The best zootechnical performances were recorded in experimental groups receiving the mycotoxin binder, compared to the control. The average weight in the finishing phase for the experimental groups was 3083.6 ± 140.7 g/subject, which was higher than the control group (2800 g/subject) (P

Mycotoxins are present in food and cannot be eliminated even by using modern technological processes in food manufacture; they can cause pathologies and economic losses in the poultry industry. To combat their effects, this study aimed to test the incorporation of a mycotoxin binder (MICOTEC 0.1%) associated with an acidifier (TECAVIAR 0.1%), both marketed in Algeria, in the feed distributed to broilers. During this study, a beneficial effect was found in subjects consuming the supplemented food compared to the control subjects. In addition to the significant decrease in mortality (51.47%), test subjects showed an average weight of 3308.1 g, which was significantly higher than control subjects (2876.25 g). The data revealed a significant reduction in the number of total and faecal coliforms, with prevalence ranging from 3.1 to 36.5% vs 63.2 to 96.9% for the control group. An increase in the length of the small intestine (24.13 cm), increase in the weight of the Fabricius bursa (FB; 1.25 g), weight of the gizzard (10.25 g) and finally an increase in the weight of the wishbone (153.87 g) were recorded in the test subjects. The results indicate that the association of mycotoxin binder-acidifier in broiler chickens can improve growth performance. Further experiments are required to confirm more effects (with different doses, different strains, and other organs).

Combatting mycotoxins and their harmful effects on performance at broiler farms is based on using neutralizing products such as binders that inhibit their intestinal absorption and bind with these molecules to neutralise. This study focuses on the dietary supplementation of a mycotoxin binder-organic acidifier combination over an entire broiler rearing cycle. 1280 1-day-old chicks of equal weight of the cobb500 strain were divided into two groups (n=640): the control group (C) was fed with standard staple food suitable for each phase of breeding, while the experimental group received the same food for each phase as the control group, with the addition of a mycotoxin binder (MICOTEC, 0.1%) and organic acidifier (TECAVIAR, 0.1%) in the food. The results showed a highly convincing effect of these two additives on zootechnical performance: reduced mortality rate, 15.38% improvement in average weight, 15.68% improvement in average daily gain (ADG), and a 1.59% reduction in consumption compared to the control group. This resulted in significant economic and health impacts. This study has shown that the mycotoxin binder-acidifier combination gives remarkable positive effects that may be of economic interest. Other research perspectives are opening concerning the choice of molecules and their concentrations to optimize results, and to study other aspects of the effects of this combination on poultry health and ultimately of consumer health.

Context: Climate and economic changes promote the encroachment of woody plants on marginal mountain pastures. In the Alps, the main woody invader is the nitrogen-fixing shrub Alnus viridis (green alder). Robust breeds of different ruminant species may perform well on these shrub-encroached pastures. Aims: To assess the effects of A. viridis encroachment levels of mountain pastures on the growth performance and carcass and meat characteristics of cattle and sheep. Methods: For 8-9 weeks, 22 15-month-old growing Dexter cattle and 20 7-month-old weaned Engadine sheep were grazed rotationally on pastures in a subalpine zone with four different levels of A. viridis encroachment (average: 0.8%, 28.7%, 50.3% and 67.8%). Following slaughter, the assessed carcass and meat characteristics (longissimus thoracis and biceps femoris) included physicochemical meat quality, muscle fibre typing, fatty acid profiling (intramuscular and perirenal fat) and the sensory properties of patties. Key results: The shrub encroachment levels had only minor effects on the animals. Interactions with the animal species influenced some sensory and fatty acid characteristics. The average daily gains were 201 g in the Dexter cattle and 104 g in the Engadine sheep. Both species achieved satisfactory carcass and meat quality and favourably low n-6/n-3 fatty acid ratios (0.63 and 0.68 in the intramuscular fat of the cattle and sheep, respectively). The meat from the Dexter cattle had a slightly higher cooking loss and shear force and a slightly lower proportion of fatty acids relevant to human health. Flavour appreciation was in favour of the burgers prepared from the beef. Conclusions: Both robust breeds were suitable for producing meat on extensive pastures with A. viridis encroachment of up to 70%. Based on indirect evidence, it seems that neither species consumed significant quantities of leaves or bark from the trees. Implications: Our study provides detailed information on rare robust breeds of two animal species in the context of meat production according to customer preferences. To better explain the differences between the two animal species, particularly in terms of fatty acid profiles, the role of the A. viridis understory needs to be clarified., Animal Production Science, ISSN:1836-0939, ISSN:1836-5787

Raw material mixtures in compound feeds may increase the risk of contamination with different mycotoxins, and their intake can lead to interactive toxic effects. As a result, there is a growing awareness of the risks posed to human and animal health by the presence of toxins produced by fungi in food and diet. The aim of this study is to assess the impact of the use of a mycotoxin binder (Micotec) on zootechnical performance in broilers. For this purpose, 3000 day-old chicks of the Arbor acres strain originating from the same hatchery were weighed and distributed equally into six groups [one control (C) and five experimental (Exp), as five repetitions receiving the mycotoxin binder Micotec at a dose of 0.1 kg]. All subjects (control and experimental groups) were fed a standard staple food suitable for each phase of rearing. The results showed significant differences between the experimental groups and the control one. The best zootechnical performances were recorded in experimental groups receiving the mycotoxin binder, compared to the control. The average weight in the finishing phase for the experimental groups was 3083.6 ± 140.7 g/subject, which was higher than the control group (2800 g/subject) (P, Mješavina različitih sirovina u krmnim smjesama može povećati rizik od kontaminacije s nekoliko mikotoksina, a njihov unos može dovesti do interaktivnih toksičnih učinaka. Kao rezultat, zbog prisutnosti toksina koje proizvode gljivice u hrani i prehrani postoji sve veća svijest o rizicima za zdravlje ljudi i životinja. Cilj je ove studije bio procijeniti učinak uporabe sredstva za vezivanje mikotoksina (Micotec) na zootehničku učinkovitost u tovnih pilića. U tu je svrhu, tri tisuće (3000) pilića soja Arbor acres starih jedan dan iz iste valionice izvagano je i homogeno podijeljeno u 6 skupina (1 kontrolna (C) i 5 eksperimentalnih (Exp) koje su uključivale 5 ponavljanja primanja sredstva za vezivanje mikotoksina Micotec) u dozi od 0,1 kg. Svi pilići i iz kontrole i iz eksperimentalnih skupina hranjeni su standardnom osnovnom hranom prikladnom za svaku fazu uzgoja. Dobiveni rezultati pokazali su značajne razlike između eksperimentalnih skupina i kontrolne skupine. Naime, bolja zootehnička učinkovitost u usporedbi s kontrolnom skupinom zabilježena je u eksperimentalnim skupinama koje su primale sredstvo za vezivanje mikotoksina. Prosječna masa u završnoj fazi za eksperimentalne skupine bila je 3083,6 ± 140,65 g / piliću što je više u usporedbi s kontrolnom skupinom (2800 g / piliću) (P

Mycotoxins are present in food and cannot be eliminated even by using modern technological processes in food manufacture; they can cause pathologies and economic losses in the poultry industry. To combat their effects, this study aimed to test the incorporation of a mycotoxin binder (MICOTEC 0.1%) associated with an acidifier (TECAVIAR 0.1%), both marketed in Algeria, in the feed distributed to broilers. During this study, a beneficial effect was found in subjects consuming the supplemented food compared to the control subjects. In addition to the significant decrease in mortality (51.47%), test subjects showed an average weight of 3308.1 g, which was significantly higher than control subjects (2876.25 g). The data revealed a significant reduction in the number of total and faecal coliforms, with prevalence ranging from 3.1 to 36.5% vs 63.2 to 96.9% for the control group. An increase in the length of the small intestine (24.13 cm), increase in the weight of the Fabricius bursa (FB; 1.25 g), weight of the gizzard (10.25 g) and finally an increase in the weight of the wishbone (153.87 g) were recorded in the test subjects. The results indicate that the association of mycotoxin binder-acidifier in broiler chickens can improve growth performance. Further experiments are required to confirm more effects (with different doses, different strains, and other organs)., Mikotoksini su prisutni u hrani i nije ih moguće eliminirati niti uporabom modernih tehnoloških procesa u prehrambenoj industriji; mogu prouzročitit patologije i ekonomske gubitke u peradarskoj industriji. Za borbu protiv njihovih učinaka, odlučili smo ispitati alternativne načine inkorporiranjem veziva za mikotoksin (MICOTEC 0,1 %) u kombinaciji sa sredstvom za zakiseljavanje (TECAVIAR 0,1 %), koji se prodaju na tržištu u Alžiru, u hranu koja se daje tovnim pilićima. Tijekom ove studije otkrili smo vrlo blagotvoran učinak na subjekte koji su konzumirali hranu s dodacima u usporedbi s kontrolnim subjektima. U stvari, zamijetili smo, uz značajno smanjenje mortaliteta (51,47 %), prosječnu masu od 3308,10 g, što je značajno više od one kontrolnih subjekata (2876,25 g). Uz to, podatci su otkrili značajno smanjenje broja ukupnih fekalnih koliforma, s prevalencijom u rasponu od 3,07 % do 36,50 % u usporedbi s 63,22 % do 96,93 % za kontrolnu skupinu. Zamijetili smo i povećanje duljine tankog crijeva s 24,13 cm, povećanje mase Fabriciusove burze (FB) s vrijednošću od 1,25 g, mase želudca (10,25 g) te povećanje mase jadca (153,87 g). Na temelju ovih podataka, moguće je rabiti kombinaciju veziva mikotoksina i sredstva za zakiseljavanje u tovnih pilića za poboljšanje rasta. Potrebni su dodatni eksperimenti za potvrđivanje više učinaka (s različitim dozama, različitim sojevima i drugim organima).

In this study, polymer-hybrid natural fibers composites were prepared using unsaturated polyester resin (UPR) as the matrix and a filler using date palm leaf fiber (DPLF) and orange peel fiber (OPF). The effect of DPLF and OPF on mechanical behavior (tensile strength and elongation at break), moisture absorption, UPR gel time (tgel) and peak exothermic temperature (Tpeak) were determined. The composites of UPR reinforced with DPLF and OPF were processed by hand lay-up technique. The UPR weight fraction was maintained at 90%, and DPLF/OPF proportions varied so that the percentage of natural fiber was 10 wt%. Seven (07) composites were prepared (C1, C2, C3, C4, C5, C6 and C7) with different DPLF:OPF ratios (0:0, 1:0, 0.75:0.25, 0.5:0.5, 0.33:0.67, 0.25:0.75, 0:1) respectively in order to screen the possible interactions. DPLF were surface modified using 6% Alkali treatment, OPF were used without surface modification. Unlike DPLF, OPF showed considerable increase of UPR tgel and Tpeak which act as natural inhibitor. Tensile strength and fracture strength were also impacted negatively and positively depending on the different fiber proportions. Absorption tests showed a decrease in the composites hydrophobicity which increases significantly with higher DPLF proportions.

Combatting mycotoxins and their harmful effects on performance at broiler farms is based on using neutralizing products such as binders that inhibit their intestinal absorption and bind with these molecules to neutralise. This study focuses on the dietary supplementation of a mycotoxin binder-organic acidifier combination over an entire broiler rearing cycle. 1280 1-day-old chicks of equal weight of the cobb500 strain were divided into two groups (n=640): the control group (C) was fed with standard staple food suitable for each phase of breeding, while the experimental group received the same food for each phase as the control group, with the addition of a mycotoxin binder (MICOTEC, 0.1%) and organic acidifier (TECAVIAR, 0.1%) in the food. The results showed a highly convincing effect of these two additives on zootechnical performance: reduced mortality rate, 15.38% improvement in average weight, 15.68% improvement in average daily gain (ADG), and a 1.59% reduction in consumption compared to the control group. This resulted in significant economic and health impacts. This study has shown that the mycotoxin binder-acidifier combination gives remarkable positive effects that may be of economic interest. Other research perspectives are opening concerning the choice of molecules and their concentrations to optimize results, and to study other aspects of the effects of this combination on poultry health and ultimately of consumer health., Borba protiv mikotoksina i njihovih štetnih učinaka na učinkovitost farmi tovnih pilića sastoji se od uporabe neutralizacijskih proizvoda poput veziva koji inhibiraju njihovu apsorpciju u crijevima i neutraliziraju ih vezujući se na te molekule. Ova studija se usredotočuje na dodatak prehrani u obliku kombinacije vezivanja mikotoksina i sredstva za zakiseljavanje tijekom cijelog ciklusa uzgoja tovnih pilića. 1280 jednodnevnih pilića, soja cobb500 (obaju spolova), podijeljeno je u dvije skupine (n=640) iste težine: prva, kontrolna skupina (C) hranjena je standardnom osnovnom hranom prikladnom za svaku fazu uzgoja. Za drugu skupinu, uz poštivanje iste formule za svaku fazu te istih sastojaka, dodano je vezivo mikotoksina (MICOTEC, 0,1 %) i organsko sredstvo za zakiseljavanje (TECAVIAR, 0,1 %) u hranu. Dobiveni rezultati ukazuju na vrlo uvjerljive učinke ovih dvaju aditiva na zootehničke karakteristike: smanjenu stopu smrtnosti, poboljšanje prosječne težine za 15,38 % i prosječnog dnevnog prirasta (ADG) za 15,68 % te smanjenje konzumacije za -1,59 % u usporedbi s kontrolnom skupinom. To je rezultiralo znatnim ekonomskim učinkom i učinkom na zdravlje. U ovom je radu rikazano da je kombinacija veziva mikotoksina i sredstva za zakiseljavanje osigurala vrlo važne i zanimljive pozitivne učinke koji bi mogli biti od ekonomskog interesa. Uz to, otvaraju se brojne perspektive za istraživanje za izbor molekula i koncentracija za optimizaciju rezultata, kao i za proučavanje drugih vidova učinka ove kombinacije na zdravlje ljudi i peradi.

Image time series, such as Satellite Image Time Series (SITS) or MRI functional sequences in the medical domain, carry both spatial and temporal information. In many pattern recognition applications such as image classification, taking into account such rich information may be crucial and discriminative during the decision making stage. However, the extraction of spatio-temporal features from image time series is difficult to handle due to the complex representation of the data cube. In this paper, we present a strategy based on Random Walk to build a novel segment-based representation of the data, passing from a 2D[Formula: see text] dimension to a 2D one, more easily manipulable and without losing too much spatial information. Such new representation is then used to feed a classical Convolutional Neural Network (CNN) in order to learn spatio-temporal features with only 2D convolutions and to classify image time series data for a particular classification problem. The influence of the way the 2D[Formula: see text] data are represented, as well as the impact of the network architectures on the results, are carefully studied. The interest of this approach is highlighted on a remote sensing application for the classification of complex agricultural crops.

This work aims to study the structural and elastic properties of tetragonal lead dioxide (β-PbO2) material using first-principles calculations. Features such as lattice parameters, bulk modulus and its first pressure derivative, elastic constants, mechanical parameters, sound velocities, Debye temperature and melting temperature have been investigated, and their dependence on pressure in the range 0–1 GPa has been analyzed and discussed. Upon compression, the stiffness of the material of interest is found to become larger as compared to that at zero pressure. Moreover, its tetragonal structure fulfills the mechanical stability criteria in all studied pressure range. Besides, the analysis of Pugh’s ratio shows that PbO2 behaves in a ductile manner.

Image time series (ITS) represent complex 3D (2D+t in practice) data that are now daily produced in various domains, from medical imaging to remote sensing. They contain rich spatio-temporal information allowing the observation of the evolution of a sensed scene over time. In this work, we focus on the classification task of ITS, as often available in remote sensing tasks. An underlying problem here is to consider jointly the spatial and the temporal dimensions of the data. We present Deep-STaR, a method to learn such features from ITS data to proceed to their classification. Instead of reasoning in the original 2D+t space, we investigate novel 2D planar data representations, containing both temporal and spatial information. Such representations are a novel way to structure the ITS, compatible with deep learning architectures. They are used to feed a convolutional neural network to learn spatio-temporal features with 2D convolutions, leading ultimately to classification decision. To enhance the explainability of the results, we also propose a post-hoc attention mechanism, enabled by this new approach, providing a semantic map giving some insights for the taken decision. Deep-STaR is evaluated on a remote sensing application, for the classification of agricultural crops from satellite ITS. The results highlight the benefice of this method, compared to the literature, and its interest to make easier the interpretation of ITS to understand spatio-temporal phenomena.

International audience

The beneficial effects of polyphenol intake such as improved nitrogen retention make them interesting feed supplements for ruminants. In contrast, dietary polyphenols may have adverse effects on the bioavailability of nutrients and palatability of the feed which might impair growth performance. The beneficial and adverse effects might differ between different ruminant species as well as between direct intake and intake of polyphenol metabolites via suckling when supplemented to lactating dams. This study investigated the effects of maternal and direct polyphenol supplementation via grape seed extract in sheep and goats on growth, slaughter performance, meat quality and fatty acid profile. The diet of lactating East Friesian Dairy sheep (n = 11) and Saanen goats (n = 9) and of their lambs (n = 16) and kids (n = 13), respectively, was supplemented either with grape seed extract (dams: 7.4% and offspring: 5.6%, P) or without (C). This resulted in four groups per species, namely maternalC/offspringC, maternalC/offspringP, maternalP/offspringC, and maternalP/offspringP. In lambs but not in goats, maternalP increased average daily gain and improved slaughter performance whereas offspringP had no effect. Maternal and offspring diet did not affect physicochemical meat quality in lambs, but direct intake of grape seed extract increased rancid aroma of burger patties. In goat kids, both maternal and offspring diets slightly affected meat colour. While groups of meat fatty acids (FAs) were not affected by diet in both species, maternalP in lambs as well as maternalP and offspringP in goat kids increased the meat n–6 to n–3 FA ratio compared to the respective control groups. In goat kid but not in lamb meat, direct intake of polyphenols affected the proportions of several rumen biohydrogenation intermediates. In conclusion, grape seed extract can be applied in both the maternal and offspring diets in sheep and goats while maintaining or even improving offspring growth performance and carcass quality. Only few species-specific effects of grape seed extract supplementation were observed, and additive effects were scarce. Larger studies are required to confirm the observed species-specific growth response to maternalP during lactation. The underlying reasons for this differential response need to be further evaluated., Animal, 15 (9), ISSN:1751-7311, ISSN:1751-732X

The objective of this work is to investigate the benefit of discrete wavelet transform combined with LPC, for speaker identification system applied for Algerian Berber language, compared to the traditional Mel frequency analysis. We’ve developed a speaker identification system for Algerian Berber language. The corpus concerns two dataset, the first one concerns eight isolated words and the second is dedicated for continuous speech repeated by Algerian native Berber. We’ve used MFCC feature, their first and second derivatives and discrete wavelet transform (DWT) followed by linear predictive coding (LPC) to ameliorate the parameterization phase. Mahalanobis distance, ascendant classification and pitch analysis were used for characterizing our speech signals. We evaluate the performance of DWT–LPC feature for clean and additive noisy speech. The multilayer perceptron classifier was used for this purpose, efficiency was improved for DWT combined with LPC feature vectors.

The aim of the present work is the study of the performances of dry cells containing the electrolytic MnO2, natural MnO2, or a mixture of both. The two components have been characterized by chemical analysis. The continuous discharge tests done on the dry cells based on EMD present a discharge time largely greater than that of the pure NMD; however, the cells containing a mixture present intermediate values of the discharge time. The value of the diffusion coefficient estimated by the GITT or impedance spectroscopy shows that the H+ diffuses more quickly in the EMD variety that in the NMD one.

The study of the reliability of PV systems, although they are answered in the world, is rare. In Algeria we have recorded any university research laboratory on the subject, despite the government gives great importance to the development of PV systems from us. It is therefore important to know the reliability, availability and sustainability of these systems. This will help to objectively determine the lifetime of a PV system before the costs become more important than the gains from the system. The objective of this work is to calculate the reliability of the MPPT of PV system and simulate the combination of a photovoltaic panel with a DC/DC converter controlled by the technical Disrupts & Regards. Two choppers are available for study parallel (three conduction modes and three powers), and the chopper Cuk (for the same power).

International audience; Today toxic phenolic compounds are a major source of pollution and are mainly the result of various industrial wastes such as plastics, polymers, insecticides, etc. In this context, the originality of our study is a first as we used a new composite material assembled by mixing activated carbon (AC), organo activated bentonite (OAB), and alginate (A). The prepared adsorbent materials were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and point of zero charge (pH(PZC)). The influence of various factors such as contact time, pH, adsorbate concentration, and temperature on the adsorption of bisphenol A (BPA) and 2,4,5-trichlorophenol (TCP) has been investigated. The equilibrium data were fitted well by Freundlich isothermal model and the maximum adsorptions of BPA and TCP onto alginate/organo activated bentonite/activated carbon beads (A-OAB-AC), were 368.2 and 385.1 mg.g(-1), respectively. The adsorption of BPA and TCP was observed to follow pseudo-second order mechanism as well as the thermodynamic parameters confirm also endothermic spontaneous and physiosorption processes. In addition, the resulting adsorbent reusability was demonstrated by at least six cycles, indicating that the A-OAB-AC can be used as a promising adsorbent for removal of toxic pollutants from aqueous solutions.

This paper presents a method of tracking points on a speaking face and the reconstruction of a face model from speaking descriptive vectors followed. After capturing a video of a talking face using a CCD camera, his facial expression changes in a video sequences. The essencial of this work is to track the feature points on the face using the Lucas-Kanade method, then use descriptive vectors up to be exploited for the reconstruction of a model of speaking face. The tracking method used is based on the theorem of Lucas-Kanade and facial reconstruction based on the method of delaunay triangulation.

Th is article p resents a robust method for detecting iris features in frontal face images based on circular Hough transform. The software of the applicat ion is based on detecting the circles surrounding the exterio r iris pattern from a set of facial images in d ifferent color spaces. The circular Hough transform is used for this purpose. First an edge detection technique is used for finding the edges in the input image. After that the characteristic points of circles are determined, after which the pattern of the iris is extracted. Good results are obtained in different color spaces.

A potential solution for stand-alone power generation is to use a hybrid energy system in parallel with some hydrogen energy storage. Renewable energy sources (solar, wind, etc) are attracting more attention as alternative energy sources to conventional fossil fuel energy sources. This is being used widely for substitution of oil-produced energy and will help to minimize atmospheric degradation. One third of the world population does not have access to clean water sources and most of these people are not connected to the electrical grid at the same time. In this paper, a hybrid Photovoltaic (PV)-fuel cell generation system employing an electrolyzer for hydrogen generation is designed and simulated. The system is applicable for a desalination plant loads. Reverse osmosis (RO) is an electrically driven technology characterized by significantly low specific power requirements. In the meantime, coastal arid areas are blessed with exceptionally high solar radiation most of the year. Normally, those areas have no access to municipal water network and the local power grid. Thus, the water problem can also be seen as an energy problem since seawater, brackish water or freshwater of unknown quality are abundantly available but significant amounts of energy are required in order to make it suitable for drinking. Photovoltaic (PV) powered water purification is an opportunity to solve this issue. It can provide potable water and on top, small independent minigrids that supply people with electricity, too. The proposed configuration, even if it is not entirely autonomous still requires a smaller area of solar panel to operate. By cons, there remains the problem of the source of hydrogen. If hydrogen is not produced by electrolysis but by reforming hydrocarbons, this means CO2 emissions, with resources that are not inexhaustible. Moreover, 95% of the hydrogen currently produced using this method. For a massive use of hydrogen consumption, it will consider new production methods, such as the construction of nuclear power plants dedicated to hydrogen production with such high-temperature electrolysis.

The aim of our article is to design a speaker identification system applied to the Berber language, based on linear predictive coding parameterization and maximum likelihood classification. Our objective is to establish a system for speaker identification in dependent and independent mode using continuous speech with duration of 2 or 3 seconds. To ensure that task, we have decided to employ some features based on the Linear Predictive Coding (LPC). The used classifier is based on the maximum likelihood principle. Furthermore, a speech dataset from Berber language and using emphatic syllables was recorded in laboratory and analysed off-line. The experimental evaluations were performed using the first and second derivatives of the descriptors, and the fundamental frequency (i.e. pitch). Results show that the proposed features and approach are interesting in speaker identification.

The proton diffusion coefficient for both fresh and heat-treated (140 and 230 °C, respectively) α and β-PbO 2 electrodes was estimated at room temperature using Galvanostatic Intermittent Titration Technique (GITT). PbO 2 samples were prepared by electroformation of cured plates. HSbO 3 · x H 2 O with a conductivity of 3.29 × 10 −3 Ω −1 cm −1 , was used as solid protonic conductor (SPC) electrolyte. It was found that when structural water is removed, the capacity of both α and β-PbO 2 electrodes decreases and the ohmic drop increases. The departure of structural water affects considerably the value of proton diffusion coefficient.

Face recognition has received a great attention from a lot of researchers in computer vision, pattern recognition, and human machine computer interfaces in recent years. Designing a face recognition system is a complex task due to the wide variety of illumination, pose, and facial expression. A lot of approaches have been developed to find the optimal space in which face feature descriptors are well distinguished and separated. Face representation using Gabor features and discrete wavelet has attracted considerable attention in computer vision and image processing. We describe in this paper a face recognition system using artificial neural networks like multilayer perceptron (MLP) and radial basis function (RBF) where Gabor and discrete wavelet based feature extraction methods are proposed for the extraction of features from facial images using two facial databases: the ORL and computer vision. Good recognition rate was obtained using Gabor and DWT parameterization with MLP classifier applied for computer vision dataset.

The influence of ‘hydrogen loss’ on the electrochemical properties of both ;-PbO2 and ;-PbO2 was studied using galvanostatic discharge and cyclic voltammetry. The thermal decomposition of electroformed PbO2 shows two types of hydration water: the first type, which disappears at low temperature, is adsorbed on the surfaces of the PbO2 particles, and the second one is localized within the PbO2 crystal structure. The reduction process of PbO2 in lead/acid cells is mainly determined by diffusion processes within the oxide. The hydrogen diffusion coefficient tH in lead dioxide has been determined at 25 °C; the values obtained are between 0.42 and 1.67 × 107 cm2 s1. The remo. The removing of ‘structurally bonded’ water, by heating the samples at 230 °C, affects considerably the electrochemical properties of PbO2 and leads to a decrease in tH..

It is well known that lead dioxide contains, what has been called, ‘structural water’. Present in the form of OH− ions replacing O2− ions in the anionic sublattice, the ‘structurally bonded’ water can be removed by heating, in the temperature range from 150 to 250 °C. In the present study, the discharge capacities of fresh and heat-treated (140 and 230 °C, respectively) α- and β-PbO2 samples were evaluated in H2SO4 solution of 1.28 g cm−3 sp. gr. at different current densities of 5 to 40 mA cm−2. It was found that the capacity decreased when structural water was removed. This loss of capacity is important when α-PbO2 samples are considered. The energy of dehydroxilation was deduced by applying kinetic considerations to thermograms, obtained experimentally. The removal of the OH− groups from β-PbO2 needs an energy twice that of the α-form.

The influence of the initial amount of H2SO4 added to lead powder on the phase compositions of plates in the curred and formed states has been studied. IR spectra, X-ray diffraction, scanning electron microscope observations, and wet-chemical analysis are used as techniques of investigation. It was found that the phase composition of the paste depends on the H2SO4:oxidized lead powder ratio. In addition, it is found that α- and β-PbO2 are formed in the lead/acid battery positive from 3PbO·PbSO4·H2O. the amounts of these two compounds were strongly affected when varying the quantity of H2SO4 with respect to the lead powder.

The cathodic behaviour of both varieties a - and β-PbO 2 in the presence of lithium ion was studied. The chemical lithiation was obtained by reaction with n-butyllithium. The chromatographic analysis of the chemical products revealed both octane and butane. The presence of butane as coproduct could be due to the hydrogen substitution reaction with n-butyllithium. The electrochemical behaviour was studied with deposited PbO 2 cathodes on stainless steel with a LiClO 4 /polyethylene oxide electrolyte. By using slow scan voltammetry, the cathodic reduction process results in the peak reduction at potential 2.4 V versus Li/ Li + for α-PbO 2 and 2.74 V versus Li/Li + for β-PbO 2 . The present work suggests that cathodic reduction is lithium intercalation in surface-layered PbO 2 molecules.

The thermal degradation of α and β PbO 2 and its relationship to capacity loss was studied using galvanostatic discharge and voltamperometry. The results clearly demonstrate the dramatic effect of the thermal treatment on the capacity of the PAM. The variation of proton diffusion with temperature was determined for both α- and β-PbO 2 . The two forms of PbO 2 exhibit different behaviour with regard to water loss.