Study of the Dielectric Relation and the Doping Effect on Conductivity in Lithium Tantalate

Ceramics Li0.98-xTa1.004-x/5NixO3 (LTN) samples have been prepared, for x{0;0.01;0.02;0.05;0.08;0.15;0.2}. Ac impedance measurements were carried out in the frequency range 1Hz-1MHz and from 300°C to 900°C. The influence of Ni doping on dc conductivity was depicted. Through the ac impedance, dielectric constant was deduced and two dielectric relaxations have been clearly identified at high temperature. The low frequency relaxation is attibuted to the space charges, and the high frequency one to ferroelectric dipoles. Systematic fits have been done using the Cole-Cole model. It’s appears for identified relaxations, that at the temperature close to Tc, the dispersion step Δ ε is maximum ; the relaxation time τ is thermally activated and also present an extremum at Tc. The influence of Ni doping on these relaxations, specially the relaxation of the space charges was examinedCeramics Li0.98-xTa1.004-x/5NixO3 (LTN) samples have been prepared, for x{0;0.01;0.02;0.05;0.08;0.15;0.2}. Ac impedance measurements were carried out in the frequency range 1Hz-1MHz and from 300°C to 900°C. The influence of Ni doping on dc conductivity was depicted. Through the ac impedance, dielectric constant was deduced and two dielectric relaxations have been clearly identified at high temperature. The low frequency relaxation is attibuted to the space charges, and the high frequency one to ferroelectric dipoles. Systematic fits have been done using the Cole-Cole model. It’s appears for identified relaxations, that at the temperature close to Tc, the dispersion step Δ ε is maximum ; the relaxation time τ is thermally activated and also present an extremum at Tc. The influence of Ni doping on these relaxations, specially the relaxation of the space charges was examined

Leach routing protocol for image transfer using Castalia simulator

International audienceIn multimedia wireless sensor network, a routing protocol plays an important role in saving the limited resources of sensors. It allows a node to transmit a multimedia content, an image in our case, to the sink. In this paper, we are going to use the Castralia simulator to test different configurations of leach routing protocol. The aim of these tests is to determine how we can transmit the biggest number of images through network with minimum energy consumption

Primary renal osteosarcoma: A case report

Primitive renal osteosarcoma is a rare sarcoma of the kidney with only 27 cases reported in the literature. Itshistogenesis is poorly understood. It occurs at an older age between the fifth and seventh decade of life witha male predominance. The clinical features are similar to other renal diseases. Imaging shows calcificationswithin a lumbar or flank mass. Histology describes a sarcomatous proliferation producing osteoid, mostoften at an advanced stage (pT4), which implies a poor prognosis. We report on the clinical and pathologicfeatures of a case of primary renal osteosarcoma in a 56-year-old man with stage IV disease. This is the 28th case of primitive renal osteosarcoma reported in the literature, confirming the highly malignant natureof this tumor and the need for early diagnosis

Variability of a portion of RNA 3 containing the coat protein gene of Citrus variegation virus (CVV) using single-strand conformation polymorphism (SSCP)

A portion of RNA 3 of Citrus variegation virus (CVV), comprising part of the intergenic region and the coat protein (CP) gene from eight viral isolates, was amplified by RT-PCR and cloned. The clones were compared for intra and inter-isolate variations by single-strand conformation polymorphism analysis. Some of the results were compared with sequence data previously obtained. The test discriminated between clones differing in as little as 3.2% of the nucleotides. Most isolates included several variants, in some cases with a predominant pattern, which, however, could no longer be recognised in new RT-PCR products obtained 13 months later. This procedure can there-fore be used to identify and detect variations between CVV isolates. It is rapid, inexpensive and may reduce the amount of sequencing needed for comparing viral isolates

Design of compact microstrip bandpass filter using square DMS slots for Wi-Fi and bluetooth applications

This paper presents the design of a compact bandpass filter based on two identical rectangular resonators and is implemented on microstrip technology for Wi-Fi and bluetoothapplications. To reduce the size of the filter, the defected microstrip structure (DMS) technique is proposed. This technique consists of etching slots in the rectangular resonator, which results in a change in the line properties and increase of the effective inductance and capacitance. This feature is used for miniaturization. The designed filter has a compact size (6.82x8.3) mm² with a low insertion loss of -0.1 dB and a good return loss of -36 dB. The simulation results are realized using the (computer simulation technology) CST Microwave software

Polymorphisme de l’apolipoprotéine E dans la population du nord du Maroc: fréquence et influence sur les paramètres lipidiques

Introduction: L'objectif de ce travail est de déterminer les fréquences alléliques et génotypiques des sites polymorphes situés dans le gène de l'apolipoprotéine E (apo E) ainsi que leur impact sur les paramètres cliniques et lipidiques dans un échantillon de la population du nord du Maroc cliniquement diagnostiqué ADH. Méthodes: Le génotype de l'apo E a été analysé par séquençage direct chez 46 patients cliniquement diagnostiqués ADH selon les critères standards. Résultats: Les fréquences des allèles epsilon 3, epsilon 2 et epsilon 4 ont été respectivement 78.3%, 2.2% et 19.6%. La fréquence de l'allèle epsilon 4 est très élevée chez la population du nord du Maroc en comparaison avec les populations des autres régions marocaines. Elle est similaire à celle rapportée dans les pays de l'Europe du nord. Les taux du cholestérol total, du cholestérol LDL ainsi que la présence des xanthomes et les maladies cardiovasculaires ne différent pas entre les génotypes de l'apoE. En revanche, les résultats ont montré une influence de l'allèle epsilon4 sur le taux des triglycérides chez les sujets obèses. Conclusion: Le génotype de l'apoE ne peut expliquer le phénotype clinique et biochimique présenté par des patients du Nord du Maroc cliniquement diagnostiqués ADH.Key words: Paramètres lipidiques, Maladies cardiovasculaires, Polymorphisme génétique, Gène APO