Contribution à la résolution du problème direct en scatterométrie par réseaux de neurones

Le travail consiste à résoudre le problème direct par réseaux de neurones (PMC). Au départ ce problème se résolvait par la méthode modale par développement de Fourier. Pour notre étude, La résolution de ce problème consiste à la détermination de la signature Scatterométrique théorique d’un réseau périodique (intensités lumineuses) connaissant certains paramètres (dimensions géométriques, indices des matériaux, période et la longueur d’onde etc.). L’étude est de créer un RN et de lui fournir les dimensions du profil et de déterminer les intensités lumineuses (Is et Ic), puis comparer les signatures calculées par la MMMFE et le RN en calculant l’erreur quadratique et tracer les courbes de comparaison de ces signatures.Mots-clés: scatterométrie, MMMFE, réseau de neurones, Matlab. Contribution to the solution of the direct problem in scatterometry with neural networksThe work is to solve the direct problem by neural networks (PMC). Initially this problem solved by the modal method by Fourier expansion. For our study, the resolution of this problem consists in determining the theoretical scatterometric signing of a periodic array (light intensity) knowing certain parameters (geometrical dimensions, materials indices, period and wave Length etc.). The study is to create a RN and provide the profile dimensions and determine the light intensity (Is and Ic), and then compare the signatures calculated by MMMFE RN and by calculating the mean square error and trace curves comparison of these signatures.Keywords: scatterometry, MMMFE, neural Network, Matlab

Is neck circumference measurement an indicator for abdominal obesity? A pilot study on Turkish Adults

Background: Neck circumference (NC) measurement is one of the simple screening measurements which can be used as an index of upper body fat distribution to identify obesity.Objectives: The aim of this study was to determine the relationship between neck circumferences and obesity.Methods:A total 411 volunteer adults participated in this study (174 men, 237 women). A questionnaire which consisted of anthropometric measurements and demographic features was used. Patients with NC ≥37 cm for men and ≥34 cm for women require evaluation of overweight status.Results: The percentages of the men and women with BMI ≥ 25kg/m2 were 55.2% and 27.0% respectively and with high neck circumferences were 85.1% and 38.8%, respectively. The percentages of the men and women with high waist circumference were 31.6% and 79.3%, respectively. In both gender there were positive significant correlations between neck circumference, body weight (men, r=0.576; women, r=0.702; p=0.000), waist circumferences (men, r=0.593; women r=0.667; p=0.000), hip circumferences (men, r=0.568; women, r=0.617; p=0.000) and BMI (men, r=0.587; women, r=0.688; p=0.000).Conclusions: This study indicates that NC was associated with body weight, BMI, waist and hip circumferences and waist/hip ratio for men and women. A significant association was found between NC and conventional overweight and obesity indexes. NC was associated with waist/hip ratio for men and women.Key words: Neck circumference, obesity

Epidemic Exposure, Financial Technology, and the Digital Divide

We ask whether epidemic exposure leads to a shift in financial technology usage and who participates in this shift. We exploit a dataset combining Gallup World Polls and Global Findex surveys for some 250,000 individuals in 140 countries, merging them with information on the incidence of epidemics and local 3G internet infrastructure. Epidemic exposure is associated with an increase in remote-access (online/mobile) banking and substitution from bank branch-based to ATM activity. Heterogeneity in response centers on the age, income and employment of respondents. Young, high-income earners in full-time employment have the greatest tendency to shift to online/mobile trans-actions in response to epidemics. These effects are larger for individuals with better exante 3G signal coverage, highlighting the role of the digital divide in adaption to new technologies necessitated by adverse external shocks

Average Structures of a Single Knotted Ring Polymer

Two types of average structures of a single knotted ring polymer are studied by Brownian dynamics simulations. For a ring polymer with N segments, its structure is represented by a 3N -dimensional conformation vector consisting of the Cartesian coordinates of the segment positions relative to the center of mass of the ring polymer. The average structure is given by the average conformation vector, which is self-consistently defined as the average of the conformation vectors obtained from a simulation each of which is rotated to minimize its distance from the average conformation vector. From each conformation vector sampled in a simulation, 2N conformation vectors are generated by changing the numbering of the segments. Among the 2N conformation vectors, the one closest to the average conformation vector is used for one type of the average structure. The other type of the averages structure uses all the conformation vectors generated from those sampled in a simulation. In thecase of the former average structure, the knotted part of the average structure is delocalized for small N and becomes localized as N is increased. In the case of the latter average structure, the average structure changes from a double loop structure for small N to a single loop structure for large N, which indicates the localization-delocalization transition of the knotted part.Comment: 15 pages, 19 figures, uses jpsj2.cl

Finite size melting of spherical solid-liquid aluminium interfaces

We have investigated the melting of nano-sized cone shaped aluminium needles coated with amorphous carbon using transmission electron microscopy. The interface between solid and liquid aluminium was found to have spherical topology. For needles with fixed apex angle, the depressed melting temperature of this spherical interface, with radius $R$, was found to scale linearly with the inverse radius $1/R$. However, by varying the apex angle of the needles we show that the proportionality constant between the depressed melting temperature and the inverse radius changes significantly. This lead us to the conclusion that the depressed melting temperature is not controlled solely by the inverse radius $1/R$. Instead we found a direct relation between the depressed melting temperature and the ratio between the solid-liquid interface area and the molten volume.Comment: to appear in Philosophical Magazine (2009

Etude des propriétés magnéto-optiques des couches minces à base de ferrite de cobalt obtenues par voie sol-gel

Ce travail est consacré à l'étude des propriétés magnéto-optiques (rotation Faraday) de couches minces à base de ferrite de cobalt obtenues par voie sol-gel. La contribution de la méthode sol-gel utilisée est très importante et cela permet d’obtenir des couches minces ayant une bonne qualité optique. Cette démarche nécessite juste l’utilisation de liquides magnétiques ou ferro fluides, de précurseurs de silice (pas cher) et d’un substrat de verre. Le but est d’obtenir des couches minces et étudier leurs propriétés magnéto-optiques. Les courbes obtenues à la longueur d’onde de 820 nm présentent des cycles d’hystérésis avec des rotations rémanentes de 40, 60 et 81°/cm. Ces résultats présentent une excellente rotation Faraday de 212, 318 et 340°/cm à la longueur d’onde de 820 nm. Ceci montre la forte potentialité de la matrice sol-gel dopée.Mots-clés: nanoparticules magnétiques, ferrite de cobalt, sol-gel, couches minces, rotation Faraday. Study of themagneto-optical properties of thin films cobalt ferrite obtainedby the sol-gel This work is devoted to the study of magneto-optical (Faraday rotation) of thin cobalt ferrite layers obtained by sol-gel. The contribution of the sol-gel method is very important and it allows obtaining thin film shaving a good optical quality. This requires only the use of magnetic fluids or ferro fluids, silica precursors (cheap) and a glass substrate. The goal is to obtain thin layers and study their magneto-optical properties. The curves obtained for the wave length of 820 nm have hysteresis loops with retentive rotations of 40, 60 and 81°/ cm. These results show excellentFaradayrotation 212, 318 and 340°/cm ata wave length of 820 nm. This shows the high potential of the doped sol-gel matrix.Keywords: agnetic nanoparticles, cobalt ferrite, sol-gel, thin films, Faraday rotation

Knowledge, practice and acceptability of HPV vaccine by mothers of adolescent girls in Ilorin, Nigeria

Background: Human Papilloma Virus (HPV) is a sexually transmitted cause of carcinoma of the cervix. An important determinant of the success of a primary preventive strategy like HPV vaccination is the knowledge and willingness of parents to vaccinate adolescents before sexual debut. Materials and methods of study: A cross sectional descriptive survey of mothers of girls in 8 secondary schools in Ilorin was carried out from February to April 2015. Schools were selected using multi staged sampling. Descriptive and inferential statistics were performed with Chi Square and ANOVA. Results: There were 470 questionnaires returned for analysis out of 600, giving a response rate of 78.3%. One hundred and sixty-one (34.3%) knew HPV to be sexually transmitted infection and 40.4% knew it was the cause of cervical cancer. While 35.1% were aware of HPV vaccine, only 1.9% had ever vaccinated their children.Less than half (44.9%) were willing to vaccinate their children. Women with good knowledge of HPV and cervical cancer were more willing to vaccinate their children than women with poor knowledge (P <0.001). Conclusion: There is poor knowledge of HPV and practice of vaccination among mothers in llorin. Willingness of mothers to vaccinate their daughters is suboptimal. Mother’s knowledge is an important determinant of HPV vaccination of adolescents

Gateway vectors for efficient artificial gene assembly in vitro and expression in yeast Saccharomyces cerevisiae

Peer reviewedPublisher PD

COMPARISON OF ACTIVITY CONCENTRATIONS OF NATURAL RADIONUCLIDES IN SOILS COLLECTED AT DIFFERENT DEPTHS OF SELECTED HAND-DUG WELLS IN ABEOKUTA

This study was aimed at measuring and comparing the activity concentration of soil samples collected from some selected hand – dug wells with their corresponding depths of collection in Abeokuta metropolis. Total of twenty (20) soil samples were collected from hand-dug wells in five sites (Obada, Adigbe, Kuto, Olorunsogo, and Obantoko) within Abeokuta with four (4) soil samples from each hand-dug well at the surface, (0.0m) through to 2.25m depth. Gamma ray spectroscopy with High Purity Germanium (HPGe) detector was used for the measurements. The average activity concentrations obtained for the three natural radionuclides 226Ra, 232Th and 40K in Bq/Kg are 34.31 ± 2.01, 128.73 ± 4.41 and 152.31 ± 2.59 respectively at depth 0.00 m (surface), 23.00 ± 1.61, 68.39 ± 3.24 and 191.08 ± 3.11 respectively at depth 0.75 m, 31.52 ± 2.21, 145.37± 4.95 and 375.56 ± 5.50 respectively at 1.50 m and lastly 28.57±1.70, 95.61 ± 3.71 and 181.10 ± 3.94 respectively at 2.25 m depth. The world average activity concentrations for 226Ra, 232Th and 40K are given to be 35 Bqkg-1, 30 Bqkg-1 and 400 Bqkg-1 respectively (UNSCEAR 2000). 232Th showed  higher average values than the world’s average while averages of 226Ra and 40K were lower but most of the activity concentration values obtained in some of the locations are higher than the world’s average values, especially 226Raand 232Th in the soil samples.

Accurate structure factors from pseudopotential methods

Highly accurate experimental structure factors of silicon are available in the literature, and these provide the ideal test for any \emph{ab initio} method for the construction of the all-electron charge density. In a recent paper [J. R. Trail and D. M. Bird, Phys. Rev. B {\bf 60}, 7863 (1999)] a method has been developed for obtaining an accurate all-electron charge density from a first principles pseudopotential calculation by reconstructing the core region of an atom of choice. Here this method is applied to bulk silicon, and structure factors are derived and compared with experimental and Full-potential Linear Augmented Plane Wave results (FLAPW). We also compare with the result of assuming the core region is spherically symmetric, and with the result of constructing a charge density from the pseudo-valence density + frozen core electrons. Neither of these approximations provide accurate charge densities. The aspherical reconstruction is found to be as accurate as FLAPW results, and reproduces the residual error between the FLAPW and experimental results.Comment: 6 Pages, 3 figure