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This work presents the preparation of a gold-polypyrrole (Au-PPy) composite film on a silicon (Si) semiconductor supported by electrodeposition, and the study of its electrocatalytic activity as an anode catalyst for the glucose oxidation reaction in alkaline media. The microstructure of the as-prepared Au-PPy film is characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that the presence of the polymer film on the Si support improves the conductivity of the latter and enables better distribution of the Au microparticles on the electrode surface, thus helping to increase their catalytic activity for glucose oxidation. [ABSTRACT FROM AUTHOR]

This paper is the first that proposes an extended hybrid analytical method (HAM) based on a two-dimensional (2-D) coupling between the semi-analytical Maxwell-Fourier analysis and finite-element method (FEM) in polar coordinates. The proposed model is applied to any rotating electrical machines. The main objective of this paper is to establish the magnetic field solution in the whole machine by coupling an exact analytical model (AM), proposed for all regions having relative magnetic permeability equal to unity, with a FEM in ferromagnetic regions. The AM and FEM are coupled in both directions (r , θ) in the edge separating teeth regions and all its adjacent regions by applied boundary conditions (BCs). The developed HAM gives accurate results on the magnetic flux density distribution and the cogging torque whatever the operating conditions, the magnetic or geometric parameters. All results obtained give very satisfactory agreement with 2-D finite-element analysis (FEA). [ABSTRACT FROM AUTHOR]

In this work, we electrochemically developed a palladium–polypyrrole composite film on a silicon semiconductor support, and then studied its electrocatalytic activity — as an anode — towards the oxidation of glucose in an alkaline medium. The obtained electrode is characterized by various physicochemical techniques such as scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray fluorescence (XRF). The results show that the presence of the polymer film on the Si support improves the conductivity of the latter and that the presence of palladium on the polymer film is at the origin of the reactivity of the electrode for glucose oxidation. [ABSTRACT FROM AUTHOR]

Natural disasters and their causes are so complex and difficult to classify that some types have sudden impacts while other types have slow impacts on urban expansion areas. Flood is one of the most serious natural disasters affecting the urban environment. On the physical side, flood causes destruction of buildings and cuts in the urban fabric. However on the environmental side, flood's impacts appear inthe presence of swamps and ponds and which cause, in turn, the spread of bad odors, epidemics and diseases via running water. The latter may have a greater impact on infrastructure such as bridges, roads and the lives of residents. As for M'sila region, whenever there is heavy and sudden rain, the neighborhoods and residential communities located along El-Ksob valley, as well as the area of urban expansion, are exposed to torrential floods due to the high level of the valley water as well as El-Mwailha valley, which is located within the area of land occupancy plan(HammamDal'a Road). These floods have resulted in large losses in buildings and properties, and in some cases, victims. Therefore, this study discussessomeriskscaused by floods on the urban expansion areasin M'sila and tries to provide solutions to reducethe severity of this phenomenon. [ABSTRACT FROM AUTHOR]

Based exclusively on the exact subdomain (SD) technique and finite-difference method (FDM), this article proposes a 2-D hybrid model (HAM) for the semi-analytical magnetic field calculation in electrical machines at no-/on-load conditions. It is applied to dual-rotor permanent-magnet (PM) synchronous machines. The magnetic field is computed by solving Laplace’s and Poisson’s equations through exact SD technique in all regions at unitary relative permeability (i.e., PMs, air gap, and slots) with a numerical model based on FDM in ferromagnetic regions (i.e., teeth and rotor/stator yokes). These two models are specifically coupled in both directions (i.e., ${r}$ - and ${\theta }$ -edges) of the (non-)periodicity direction (i.e., in the interface between teeth regions and all its adjacent regions as slots and/or air gap). To provide accurate solutions, the current density distribution in slots regions is modeled by using Maxwell’s equations. The finite-element analysis (FEA) demonstrates highly accurate results of the developed technique. The 2-D HAM is ≈6 times faster than 2-D FEA. [ABSTRACT FROM AUTHOR]

The aim of this article is to propose a two environmental problems solution. One is the silting up of dams, despite the expensive dredging operations and the absence of a policy for the reuse of dredged sludge stored on non-agricultural land. The other represents the rate of cement used in the concrete. The dredged sludge is introduced after heating treatment at 600°C into the cement matrix of an ordinary concrete represents the proposed solution for both problems. In these eco-concretes, the cement has been replaced by treated dredged sludge at different percentages (5-10-20%) with a similar amount of water. Physical measurements and mechanical tests like shrinkage, absorption, and ultrasonic pulse velocity indicated dependence on substitution under dilution effect. Thermogravimetric analysis like the produced portlandite rate indicates a lack of reactive silica to supply the pozzolanic reaction. The results reveal that the substitution of 5% of cement by treated sludge leads to an appropriate concrete and minimizes the siltation effect. [ABSTRACT FROM AUTHOR]

This article proposes an extended linear analytical solution based on the exact subdomain (SD) technique applied to any flat linear electromagnetic device for no-load and armature reaction current conditions. A slotted linear synchronous machine with surface-mounted permanent magnet (PM) having Halbach magnetization is proposed in this article. The magnetic field derived from the formal solution of Maxwell’s equations is calculated by solving Laplace’s and Poisson’s equations on a 2-D Cartesian system. The magnetic field distribution is determined in all regions by considering the finite magnetic permeability of soft-magnetic materials in iron parts. It was performed for two different values of iron core relative permeability (viz., 2 and 1000). Finite-element analysis (FEA) demonstrates excellent results of the developed technique. [ABSTRACT FROM AUTHOR]

In this paper, we report a simple electrochemical strategy for the preparation of an electrode material based on polypyrrole (PPy) film grown on silicon substrate via oxidative polymerization technique and functionalized by palladium microparticles dispersed on its surface. SEM examination indicates the uniformity in loading of Pd on PPy surface forming a coral-like network structure. The XRD pattern confirms the formation of Pd. The effects of the applied potential as well as the time of electrolysis on the morphological evolution of the as-deposited Pd particles were investigated. [ABSTRACT FROM AUTHOR]

The Internet of Things (IoT) is an upcoming technology that permits to interconnect different devices and machines using heterogeneous networks. One of the most critical issues in IoT is to secure communication between IoT components. The communication between the different IoT components is insecure, which requires the design of a secure authentication protocol and uses hardness cryptographic primitives. In 2017, Wang et al. proposed an improved authentication protocol based on elliptic curve cryptography for IoT. In this paper, we demonstrate that Wang et al.'s protocol is not secure. Additionally, we propose a privacy-preserving authentication protocol using code-based cryptosystem for IoT environments. The code-based cryptography is an important post-quantum cryptography that can resist quantum attacks. It is agreed in design several cryptographic schemes. To assess the proposed protocol, we carry out a security and performance analysis. Informal security analysis and formal security validation show that our protocol achieves different security and privacy requirements and can resist several common attacks, such as desynchronization attacks, quantum attacks, and replay attacks. Moreover, the performance evaluation indicates that our protocol is compatible with capabilities of IoT devices. [ABSTRACT FROM AUTHOR]

In this work, a modified electrode of copper-polypyrrole (Cu-PPy) is elaborated by charging the polymer matrix by Cu particles. The response to ascorbic acid (AA) of this material was tested. The results show good performances. The results indicated a sensitive oxidation peak current of AA on the modified electrode. The success of this application led us to study the nucleation mechanism of copper on the PPy surface which permits to obtain this response. Nucleation and growth of electrodeposited copper onto PPy substrate have been studied in an aqueous solution of 0.01 M CuCl2 and 1 M KCl by means of electrochemical methods: cyclic voltammetry, chronoamperometry, and using atomic force microscopy (AFM). The model described by Scharifker and Hills was used to analyze current-time transients. According to this model, the nucleation and growth kinetics at the initial stages of deposition process involve an instantaneous nucleation followed by three-dimensional (3D) growth mechanism. [ABSTRACT FROM AUTHOR]

In this paper, we investigated the characteristics of a structured copper (Cu) film deposited on the surface of an insulating epoxy glass (EG) substrate via a facile electroless plating process. The film produced by this method was found to be of high purity and has a homogeneous microstructure consisting of an assembly of numerous aggregates that vary in size from 1 to 5 µm depending on the electroless deposition time. The electrocatalytic activity of the prepared electrode was investigated for the electrooxidation of formaldehyde using cyclic voltammetry in 0.1 M NaOH solution. Results show that formaldehyde oxidation takes place at a low potential of −0.34 V with large anodic current densities. [ABSTRACT FROM AUTHOR]

In this paper, we report a simple sensing strategy for electrochemical determination of ascorbic acid (AA) using a combination of polypyrrole (PPy) thin film and palladium particles composites deposited onto -doped silicon (Si) substrate. A two-step electrochemical process was employed to synthesize the composite films: At first, PPy film (average thickness 200nm) was electrogenerated on Si substrate from an organic solution of the pyrrole under galvanostatic conditions. Secondly, palladium particles were electrodeposited on PPy/Si surface from a separate solution by chronoamperometry technique. The surface morphology analysis of the obtained composites shows a uniform dispersion of palladium particles onto the polymer matrix and reveals that the electrodeposition time has a significant effect on the amount and size of the incorporated palladium particles. The electrochemical reactivity of the Pd-PPy/Si-modified electrodes towards the oxidation of AA was studied by cyclic voltammetry method in 0.1M, pH 7.0 phosphate buffer solution. The oxidation current was proportional to the concentration of AA in the range of 0.5-10mM with a detection limit of 0.2mM. [ABSTRACT FROM AUTHOR]

In Cooperative Intelligent Transport Systems (C-ITS), vehicles and Road Side Units (RSU) exchange various messages about safety, traffic control, and weather conditions. These messages are broadcast to all neighbors. Each message should be authenticated and should protect users' privacy, mainly by hiding their locations. The authentication is achieved by signing messages using a private key related to the Pseudonym Certificate (PC), provided by a Trusted Authority (TA). The PC is delivered together with messages so that receivers can authenticate the messages. Privacy is ensured by changing PCs many times during a journey, so that trackers cannot get drivers' traces. This paper proposes a novel approach to manage PC switching periods between vehicles. The proposed method uses a Common PC (CPC) during a short period before switching to a new PC. Vehicles use the same shared PC during this period to sign their messages. Simulations have been conducted in an OMNET++ environment, showing significant improvement in privacy protection compared to well-known privacy schemes. [ABSTRACT FROM AUTHOR]

One of the most important data currently shared on the Internet is images of various sizes and types, gray and color, private and public, civilian and military, medical and scientific, commercial, and others. The biggest challenge and problem is the secure transmission of these images in this insecure environment. In this context, this paper proposes a new image encryption algorithm using a hybrid of three modified and improved chaotic one-dimensional (1D) maps to avoid the shortcomings of 1D maps and multidimensional (MD) maps. A key image is used to initialize the chaotic maps and is also used as a mask in the diffusion phase with the eXclusive OR (XOR) operator. The encryption process uses ExtraParam extracted from the original image, which is very sensitive to bit changes during the initialization of the chaotic maps. The proposed encryption process consists of two main phases: confusion and diffusion processes. The proposed image encryption algorithm has successfully passed numerous tests and cryptanalysis. We also measure the proposed algorithm with various analysis experiments such as histogram and entropy analysis, the number of pixel change rate (NPCR), the unified average changing intensity (UACI), the mean square error(MSE), the peak signal-to-noise ratio (PSNR) and Key Space. The experimental results and comparative analysis show that the proposed encryption algorithm has excellent performance, is strong enough to withstand various attacks, and provides excellent privacy to digital images. [ABSTRACT FROM AUTHOR]

This article integrates a suitable controller to the direct power control algorithm for a shunt active power filter. The conventional proportional-integral (PI) controller is commonly used in DC bus regulation loops because of its advantages in the steady state, but it is limited in the dynamic state. Thus, this article contributes an appropriate controller, the fractional-order–integral-plus-proportional controller. The controller under study extends the integration order of the controller from integer to real order based on fractional calculus theory and Oustaloup continuous approximation. The fractional-order–integral-plus-proportional controller offers a short response time, withstands parameters variations, and deals with external disturbances. To investigate the efficiency and accuracy of the proposed fractional-order–direct power control algorithm considering all robustness tests, an experimental setup was made. The experimental results confirm its high performance in both steady and dynamic states and demonstrate its feasibility and effectiveness. Therefore, the shunt active power filter improves the power quality, corrects the power factor, and reduces the harmonics injected by non-linear loads. Thanks to its high level of power quality, the fractional-order–direct power control could become an interesting alternative for active power filtering. [ABSTRACT FROM AUTHOR]

Introduction: The medullary thyroid cancer or MTC occurs in 75% of cases as sporadic form and in 25% as familial form as part of the Multiple Endocrine Neoplasia Type 2 (MEN2). These MEN2, subdivided into MEN2A, MEN2B and FMTC, are containing a MTC, which can be associated with pheochromocytoma and hyperparathyroidism or without other clinical signs or isolated. They are rare hereditary diseases, transmitted as an autosomal dominant mutations associated with the RET proto-oncogene. The genotypic study is based on the detection of mutations in the RET gene, at 7 exons, which are most frequently affected and it should be explored. We report the results of the genotyping study that we have realized in patients who have a medullary thyroid cancer or MTC. Objectives: Search in patients with medullary thyroid cancer, a sequence variation of DNA in the RET gene exons (exons 8, 10, 11, 13, 14, 15 and 16), by molecular biology techniques. Suggest if this sequence variation is a mutation that can confirm the diagnosis of MEN2, for ensure at the index case, an appropriate medical supervision. Establish genetic testing for related to research carriers of the familial sequence variation of DNA. Materials and methods: Our study included 04 female patients with MEN2A or MTC diagnostic and theirs clinically heathy relatives. Genomic DNA was extracted from peripheral blood leukocytes by the salts method. Molecular analysis have concerned the 7 exons of the RET gene (8, 10, 11, 13, 14, 15 and 16), which may carry a deleterious mutation, and was performed by polymerase chain reaction (PCR) and direct sequencing (Big Dye Terminator 1-1) on ABI Prism 3130 (Applied). Results: The genetic analysis of the 7 exons of RET gene which was performed by PCR / sequencing, did not find any known germline mutation in the index cases, but reveals a variation of sequence which is C515S (TGC/AGC), located in exon 8, in a homozygous form in two patients and in heterozygote form in two patients. The study of healthy members' family volunteers showed the same variation as heterozygous or homozygous. Conclusion: After these results, we estimate that, this C515S variation of DNA sequence is a rare variant non pathogenic and cannot be considered as a mutation causing the MEN2. [ABSTRACT FROM AUTHOR]

This study aims to produce an eco-cement by using heat treated dam’s sludge as an additive to clinker. Different heat treatment cycles were applied to the dam’s sludge: three temperatures selected in the range between the dehydroxylation and decarbonation temperatures (600, 700 and 800 °C) reached by adopting different heating rates (5, 10 and 20 °C/min). The analysis of DRX, DSC–TG, FTIR results show that the heat treatment cycles let to the change of the sludge structure allowing its use as a pozzolanic additive to produce cements. The optimal heat treatment cycle is 600 °C with a holding time of 5 h and a heating rate 20 °C/min. Normalized mortars have been designed using modified cements constituted by 5% of gypsum, different percentage of heat treated sludge (5–10% and 15%) and clinker. The compressive strengths at 28 days lead to the choice of blending 85% clinker, 10% heat treated sludge and 5% gypsum to produce modified cements. The influence of the thermal activation of the dam’s sludge on the technical properties such as normal consistency, fineness, setting time, heat of hydration, compressive strength have been investigated and tests were conducted according European standards. Results reveal that heat treatment at 600 °C with a rate of 20 °C/min conducts to an activated sludge with no emission of carbon dioxide and the higher strength resistance when added to clinker at 10%. However, whatever the fineness or the rate of heat treatment, the percentage of kaolinite (11%) existing in the natural sludge is not sufficient to develop by heat treatment at 600 °C hydration products allowing significant improve of mechanical resistance of modified cements by comparison to CEMI. [ABSTRACT FROM AUTHOR]

In this paper, we have electrodeposited copper on polypyrrole surface. Results show that at high applied cathodic potential (1.8V), copper electrodeposition occurs with difficulties. The amount of electrodeposited copper is low (1.32%) and it is limited by the low polypyrrole conductivity. At this potential, poor conductivity is caused by its insulating state. However, at an applied cathodic potential of 1.2V, the polypyrrole exhibits a relatively high conductivity and copper particles are electrodeposited with large amounts (12.44%) on polypyrrole/silicon system. At high applied cathodic potential, the SEM images show clearly dispersed grains of copper, but polypyrrole surface is less occupied. At an applied cathodic potential of 1.2V, the SEM image shows that polypyrrole surface is homogenously more occupied with copper. After copper deposition, the Cu/PPy/Si system is used to catalyze the hydrogen reaction. It was found that, once the deposited copper is present with considerable amounts, the proton reduction occurs easily. As for the polypyrrole conductivity, it was found that electrodeposited copper onto PPy/Si surface affect the total conductivity. [ABSTRACT FROM AUTHOR]

In recent years, natural fibres have been experimented to replace glass fibres in reinforcing thermosetting polymer. Since the interfacial adhesion between the raw natural fibres and the polymer matrix are often not adapted to the intended applications, the fibre surface most often requires a preliminary chemical modification. The fibres which were extracted from the Arundo donax L. Plant (called cane fibres), are little studied in the literature of fibre/polymer composites. In the present work, the cane fibres have been treated at constant soaking time with 2–8% NaOH aqueous solutions for 24 h. The composite reinforced by 6% NaOH-treated cane fibres, exhibited maximum improvements in tensile and flexural strength by 57% and 45% respectively. A combination of Fourier transform infrared, scanning electron microscopy, X-ray diffraction and moisture absorption techniques has been used for material characterisation. The crystallinity index yields information about fibre modification by NaOH. Such cane fibre composites could become an alternative to existing materials, with interesting tensile and flexural strengths, low cost and less ecological impact. [ABSTRACT FROM AUTHOR]

Two methods of Pyrrole electropolymerization were investigated to prepare polypyrrole films growing onto n-doped silicon n- (111): Polypyrrole films prepared by galvanostatic method exhibits toroidal morphology for thin films, and mixture of toroidal and globular morphologies for thick films. Polypyrrole films obtained from this method were characterized by lower surface roughness. Electropolymerization of pyrrole by potentiodynamic method provided Polypyrrole films with beans-like structures for both thin and thick films with high surface roughness. Due to their lower surface roughness, polypyrrole films produced by galvanostatic method exhibit high intensities in Raman spectroscopy. These polypyrrole films show better capacitive properties according to discharge test. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the modelling of heat and mass transfer in the tubular adsorber of a solar adsorption cooling machine. The modelling and analysis of the adsorber are key facets of such studies. The adsorber is heated by solar energy and contains a porous medium constituted of activated carbon AC-35 reacting by adsorption with methanol. The results obtained provide an insight into the daily thermal behaviour of the tubular adsorber. The performance of the machine has been discussed in the studied case of 1 m2 surface area of flat plate collector integrated with nine copper tubes containing the activated carbon AC35/methanol pair. Several main factors affecting the solar and thermal performance coefficient are discussed according to the results of computer simulations. The relationship between the performance of the cycles and these factors is investigated. [Copyright &y& Elsevier]

Abstract: We present a synthetic review of elementary chemical mechanisms source of the oxidation of pure silicon (100) surfaces. These mechanisms are then discussed from their ability to build a mesoscale model of the Kinetic Monte Carlo type dedicated to the process simulation of silicon thermal oxidation. We show that oxidation is driven by two main processes: (i) charge transfer arising from the formation of Sin contact to pure silicon at the interface, (ii) destructive oxidation in which SiO building blocks rearrange at the interface to form a hexagonal-based oxide network directly in contact to cubic Si layers. Based on these considerations, simulations at the process scale exhibit epitaxial behavior within the interfacial domain. The resulting oxide layers are analyzed in terms of local to more extended defects. We observe two types of defects: (i) “intra-domain defects” which are related to local distortion of the elementary hexagonal oxide pattern Si6O6 (ii) “inter-domain defects”, which are related to global oxide structural transitions from one orientation to another. [Copyright &y& Elsevier]

We provide a description of the real interpolation spaces between the domain of the Laplace operator (with transmission conditions in a polygonal domain Ω) and Lp (Ω) as interpolation spaces between W2,p (Ω) (possibly augmented with singular solutions) and Lp (Ω). This result relies essentially on estimates on the resolvent and the reiteration theorem. [ABSTRACT FROM AUTHOR]

Abstract: Calculations based on Density Functional Theory are carried out to study interstitial generation close to the Si(100) surface with further consideration of effects related to the presence of substitutional Ge atoms on the surface. Defect structures, vacancy and Si interstitial, and associated energies are calculated. We observe that germanium atoms tend to increase the stability of created defects, promote the generation of interstitials through drastic structural changes and blocks the climb of Si interstitials towards the surface. [Copyright &y& Elsevier]

Abstract: The aim of this study is to investigate the use of waste brick as a partial replacement for cement in the production of cement mortar. Clinker was replaced by waste brick in different proportions (0%, 5%, 10%, 15% and 20%) by weight for cement. The physico-chemical properties of cement at anhydrous state and the hydrated state, thus the mechanical strengths (flexural and compressive strengths after 7, 28 and 90days) for the mortar were studied. The microstructure of the mortar was investigated using scanning electron microscopy (SEM), the mineralogical composition (mineral phases) of the artificial pozzolan was investigated by the X-ray diffraction (XRD) and the particle size distributions was obtained from laser granulometry (LG) of cements powders used in this study. The results obtained show that the addition of artificial pozzolan improves the grinding time and setting times of the cement, thus the mechanical characteristics of mortar. A substitution of cement by 10% of waste brick increased mechanical strengths of mortar. The results of the investigation confirmed the potential use of this waste material to produce pozzolanic cement. [Copyright &y& Elsevier]

An analytical model is presented, which uses two-dimensional field theory in polar coordinates to determine the flux density distribution, cogging torque, back EMF and electromagnetic torque in the slotted air gap of permanent-magnet motors with surface mounted magnet bars which are magnetized in shifting direction. The magnet arc to pole pitch ratio in the motor is not necessarily equal to unity like in the case of Halbach array magnetization. The effect of stator slots is introduced by modulating the magnetic field distribution in the slotless stator by the complex relative air-gap permeance. With this complex permeance, the radial and tangential components of flux density are calculated. In the analytical and numerical study a finite number of magnet bars, which is considered sufficient to get a sinusoidal magnetization, is used. The influence of the number of magnet bars on magnetization is also investigated. The accuracy of the developed model is verified by comparing its results with those obtained from experimental measurement and previously validated linear and nonlinear numerical finite element code. [ABSTRACT FROM AUTHOR]

We consider some unilateral boundary value problems in polygonal and polyhedral domains with unilateral transmission conditions. Regularity results in terms of weighted Sobolev spaces are obtained using a penalization technique, similar regularity results for the penalized problems and by showing uniform estimates with respect to the penalization parameter. [ABSTRACT FROM AUTHOR]

We consider some unilateral boundary value problems in polygonal and polyhedral domains with unilateral transmission conditions. Regularity results in terms of weighted Sobolev spaces are obtained using a penalization technique, similar regularity results for the penalized problems and by showing uniform estimates with respect to the penalization parameter. [ABSTRACT FROM AUTHOR]

The present paper describes an experimental method that can be used to measure the threshold voltage in MOS devices in the form of transistors or capacitors. The proposed method is based on the detection of the non-steady-state/steady-state transition of the surface potential at the oxide–semiconductor interface of a MOS device, when it is swept from depletion to inversion regions. This detection is carried out as follows: a set of current versus gate signal frequency measurements, for different voltage amplitudes, is performed. The frequency values corresponding to the maximum measured current (optimum frequency) fm, are read. Several gate voltage versus optimum frequencies (fm–VG) curves are plotted for gate voltage values ranging from 0.2 to 3 V with a 0.1 V step increment. The (fm–VG) curves are found to undergo an abrupt change of slope at a specific gate voltage value. The value of threshold voltage is extracted from the critical points of the former curves. Experiments have been carried out on different devices. The measured values of threshold voltage are found to be in good agreement to those obtained by the conventional ID–VGS and simulation methods as well as that supplied by the device manufacturer. [Copyright &y& Elsevier]

In this paper it is shown that, from the expression of the internal electric and magnetic fields, we can express the electric and magnetic energy stored inside a cavity in the form of a simple sum. This proposed method has the advantage of avoiding the calculation of a double integral which needs an appropriate numerical method. The knowledge of the radiating power can lead to the evaluation of the internal impedance at the desired frequency. Also it is shown that the electric and magnetic energy stored in a cavity can be expressed with the internal electric and magnetic fields in the form of the presented expression at resonance frequency. There is excellent agreement with the cavity method that has been confirmed by experimental results. ©1997 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: A first-principles pseudo-potential study of Frenkel pair generation close to the Si(100) surface in the presence of germanium and oxygen atoms is reported. The energies and structures of the defect structures (i.e. vacancy and relaxed tetrahedral Si interstitial) are calculated using supercell with up to 88 atoms. We present results obtained using the generalized gradient approximation (GGA) for the exchange–correlation energy. We examine the effect of the presence of germanium and oxygen atoms on the stability of Frenkel pairs generated near the Si(100) surface by comparing a number of individual cases, starting from vacancy interstitial pairs situated at various positions. The general tendency of the created interstitials is to climb towards the surface, but they generally remain in subsurface layers, ready to migrate into the layer. This tendency is enhanced by the presence of the Ge and/or O atoms. We show that the formation energy is lower and Si interstitials can be created with energies as low as 1.5eV. [Copyright &y& Elsevier]

• Porous silver film was electroless deposited onto PET substrate obtained from mineral water bottles. • Prepared Ag/PET electrode was expected to be used for hydrogen peroxide reduction reaction. • The proposed electrode is flexible, lightweight and relatively inexpensive. This work focuses on chemical preparation of structured silver film onto polyethylene terephthalate (PET) substrate and improvement in electroreduction activity of the as-prepared Ag/PET electrode material as cathode catalyst for hydrogen peroxide (H 2 O 2) reduction reaction (HPRR). The deposited silver film is homogeneous and has an open microporous structure, resulting in a high activity of the Ag/PET electrode for the HPRR. We show that the Ag/PET electrode can efficiently catalyze the HPRR with an onset potential of 0.1 V (vs.SCE). [ABSTRACT FROM AUTHOR]

This paper attempts to simulate the use of green materials from the silt in a dam, and reduce the harmful impacts of siltation on Algerian dams affected by frequent droughts and irregular rainfalls, which are resulted from climate change. These harsh weather conditions are the main cause of water erosion in Algeria, leading to a high silting level in many dams across the country. Therefore, it is necessary to dredge the considerable volumes of sludge in the dam areas. This paper treats the sludge dredged from the K'sob dam, and adds the treated sludge into cement, creating a hybrid binder that can be used in composition of cementitious materials. Specifically, the sludge extracted from the K'sob dam was characterized chemically, physically, mineralogically, and mechanically, and introduced both as a substitute of cement and a component in the mixture of ordinary concrete/mortar. The sludge was firstly activated through calcination, and added to cement at the mass dosages of 10%, 15%, and 20% separately. The mechanical behavior, especially that under compression, of cementitious materials (concrete/mortar) based on the treated sludge was studied through lab tests. The test results show that this technical innovation gives the finished product three major properties, namely, high strength, economy, and a beneficial ecological impact. The results obtained are encouraging and promise an optimal exploitation of the sludge from similar dam areas. [ABSTRACT FROM AUTHOR]

The use of waste and by-products has been for many decades for the manufacturing of building materials such as concrete and mortars. That responds simultaneously to reasons of economy of natural resources in aggregates (C&D waste) and the possibility of recovering industrial waste additions as replacement in composites. The present study focuses on the use of plastic waste fibers embedded in the cement matrix of selfcompacting concrete SCC to improve its properties, either rheological mainly, the stability at fresh state or mechanical responses such as compressive and tensile strengths at hard state. This incorporation of plastic fiber reinforcement on the structure matrix could result an alternative SCC composite as a ductile material with enhanced properties. In this context, the self-compacting composites by adding a variable percentage of plastic fibers at 0.5, 1, 1.5% is formulated. Hence, the effect of plastic fibers waste on the rheological and mechanical properties of SCC is assessed. The obtained results in the present study let us to conclude the beneficial effect of such inclusion of plastic fibers on this new confected SCC fiber composition with acceptable rheological, physical and mechanical properties compared to those of a normal SCC concrete. [ABSTRACT FROM AUTHOR]

The modernized Global Positioning System (GPS) and Galileo satellite navigation systems have recommended the interoperable Multiplexed-Binary Offset Carrier (MBOC) modulation on L1C/E1 frequency band for their open service signals. MBOC signal multiplexes BOC( 6 , 1 ) and BOC( 1 , 1 ) according to a certain proportion, and can be implemented in a number of ways, including Composite BOC (CBOC) and Time-Multiplexed BOC (TMBOC). The complexity and the accuracy of the theoretical signal modeling pose a growing concern to scrutinize and to optimize signal characteristics and receiver performances. In this paper, the analytical expressions of the optimal correlation function (CF) for the new modernized MBOC signal are proposed. Also derived are the analytical models of the discriminator functions (DFs) and the multipath error envelopes (MEEs) in both coherent and non-coherent code tracking configurations. The validation of the proposed models is performed and the simulation results show that the proposed analytical models coincide with the numerical ones. [ABSTRACT FROM AUTHOR]

Highlights: [•] Design of 1D FIR filters by conventional methods is not optimal. [•] This work sets out to propose a hybrid genetic approach for FIR filters design. [•] The local search allows the GA to escape from local optima and premature convergence. [•] Hybrid GA significantly reduces the computation cost and improves results. [ABSTRACT FROM AUTHOR]

This article studies the performance of two metaheuristics, particle swarm optimization (PSO) and genetic algorithms (GA), for FIR filter design. The two approaches aim to find a solution to a given objective function but employ different strategies and computational effort to do so. PSO is a more recent heuristic search method than GA; its dynamics exploit the collaborative behavior of biological populations. Some researchers advocate the superiority of PSO over GA and highlight its capacity to solve complex problems thanks to its ease of implementation. In this paper, different versions of PSOs and GAs including our specific GA scheme are compared for FIR filter design. PSO generally outperforms standard GAs in some performance criteria, but our adaptive genetic algorithm is shown to be better on all criteria except CPU runtime. The study also underlines the importance of introducing intelligence in metaheuristics to make them more efficient by embedding self-tuning strategies. Furthermore, it establishes the potential complementarity of the approaches when solving this optimization problem. [ABSTRACT FROM AUTHOR]

The processability of conductive polymers still represents a challenge. The use of potato starch as a steric stabilizer for the preparation of stable dispersions of polyaniline (emeraldine base, EB) is described in this paper. Biocomposites are obtained by oxidative polymerization of aniline in aqueous solutions containing different ratios of aniline and starch (% w/w). PANI-EB/Starch biocomposites are subjected to structural analysis (UV-Visible, RAMAN, ATR, XRD), thermal analysis (TGA, DSC), morphological analysis (SEM, Laser Granulometry), and electrochemical analysis using cyclic voltammetry. The samples were also tested for their solubility using various organic solvents. The results showed that, with respect to starch particles, PANI/starch biocomposites exhibit an overall decrease in particles size, which improves both their aqueous dispersion and solubility in organic solvents. Although X-ray diffraction and DSC analyses indicated a loss of crystallinity in biocomposites, the cyclic voltammetry tests revealed that all PANI-EB/Starch biocomposites possess improved redox exchange properties. Finally, the weak interactions at the atomic-level interactions between amylopectin–aniline and amylopectin–PANI were disclosed by the computational studies using DFT, COSMO-RS, and AIM methods. [ABSTRACT FROM AUTHOR]

The surface detected motor unit action potential (MUAP) morphology depends on many physiological and anatomical characteristics of the contracting muscle that are not directly accessible to measurement. In this paper, a neural network based approach is proposed to estimate the motor unit (MU) parameters from a simulated single surface MUAP. We have developed an estimation system that is composed of the following stages: conduction velocity estimation, signal dimension reduction, MU parameters estimation, and number of MU fibres estimation. The parameter estimation stage employs four multilayer neural networks trained on simulated MUAPs corresponding to various ranges of MU parameters. In the estimation mode, this module produces four MU parameters sets. The selected set of the five muscle characteristics is that which minimises an error criterion on a signal reconstructed from the estimated parameters. The proposed system is tested with several simulated MUAPs signals with additive white noise in order to evaluate its performance. It is shown that the technique performs well when the signal to noise ratio is greater than 20 dB. [Copyright &y& Elsevier]