113 research outputs found
A New Design of a Wideband Miniature Antenna Array
In this work, we present a new configuration of a new miniature microstrip antenna array having a wide frequency band and with a circular polarization. The bandwidth is about 2GHz for a reflection coefficient under -10dB and centered on the ISM ‘Industrial Scientific Medical’ band at 5.8 GHz. To design such array, we have started the design by validating one antenna element at 10 GHz and after that by using the technique of defected ground, we have validated the antenna array in the frequency band [4 GHz -6 GHz] which will permit to miniature the dimensions. The final fabricated antenna array is mounted on an FR4 substrate, the whole area is 102.48 X 31.39 mm2 with a gain of 5dBi at 4GHz
Robust and Efficient Self-Adaptive Position Tracking in Wireless Embedded Systems
© 2015 IEEE.Apart from static deployments, sensor nodes in Wireless Sensor Networks (WSNs) are unaware of their location information. In order to estimate their actual or relative positions with respect to other nodes, they are required to self-localize themselves by collecting information from their environment. However, due to the high dynamism and the noise introduced by the WSN environment, self-localization procedures are not straightforward and they may require quite sophisticated algorithmic techniques to satisfy precision requirements of the WSN applications. Among the self-localization procedures in the literature, the ones based upon the technique of trilateration are easy to implement and efficient in terms of resource requirements. On the other hand, their performance is fragile against environmental dynamics. Besides, even though multilateration based procedures are reported to be more robust, their practicability in WSNs seems questionable due to their high resource requirements. In this paper, our objective is to develop a practical self-localization procedure for WSNs that puts away the fragility against noisy ranging measurements in an efficient manner. To that end, we take a different approach to self-localization procedure and treat it as a search process during which sensor nodes find their relative positions without knowing the actual correct values. We present a novel trilateration-based self-localization procedure by exploiting a robust and efficient search technique, named Adaptive Value Tracking (AVT), that finds and tracks a dynamic searched value in a given search space through successive feedbacks. We evaluate this procedure on a real test bed setup and show that our approach to self-localization is efficient, robust to environmental dynamics and adaptive in the sense of reacting to position changes
Multidisciplinary study of Laurus Nobilis essential oil: From chemical composition to molecular interactions
This study delves into the chemical composition of Laurus Nobilis (LN) essential oil, employing gas chromatography-mass spectrometry (GC-MS) and solid-phase microextraction (HS-SPME). The hydrodistillation process yielded essential oil at 0.5 % on a dry mass basis. Notably, the essential oil is characterized by a predominant presence of eucalyptol and linalool, collectively constituting 64.33 % of the total composition. Additionally, the research sheds light on the antioxidant properties of Laurus Nobilis supported by outcomes from DPPH analysis, b-carotene bleaching, and ABTS+ cation decolorization tests. The DPPH free radical scavenging assay demonstrated an IC50 of 0.86 ± 0.38 mg/ml. The b-carotene/linoleic acid bleach test indicated a IC50 of 2.58 ± 0.10 mg/ml. Comparatively, the ABTS assay revealed antioxidant activity slightly lower than that of ascorbic acid. Molecular docking studies identified caryophyllene, g-elemene, (-)-spathulenol, a-terpineol acetate, and a-terpineol as compounds with the highest anchoring scores on target proteins. These findings underscore the therapeutic significance in modulating target proteins.
Keywords: GC-MS; HS-SPME; Molecular docking; Antioxidant activity; Antibacterial activit
Addiction aux écrans chez le jeune enfant et ses effets sur le développement cognitif
Les écrans ont pris une place considérable dans notre vie quotidienne, les enfants en font une consommation massive en tous genre.Une consommation abondante peut conduire à une dépendance qui ne peut être sans incidences négatives sur tous les champs de la santé : somatique, cognitif et social.Le but de ce travail est d’évaluer les effets de l’exposition chronique aux écrans sur le développement cognitif du jeune enfant.Méthodologie: étude descriptive menée sur un échantillon de 100 élèves. L’addiction aux écrans est évaluée par l’échelle de la dépendance. Le parcours scolaire, le langage, l’attention, le sommeil et le comportement agressif et impulsif sont évalués à l’aide d’un hétéroquestionnaire.Résultats : Les élèves participant à l’étude ont un âge moyen de 10,93 ans. L’échelle de dépendance a retrouvé une notion de dépendance dans 73% des cas. La dépendance aux écrans atteint environ un quart de l’échantillon (27%). L’ensemble des élèves dépendant consomment la télévision, 29.6% consomment l’ordinateur, 37% le téléphone portable, 18.5% utilisent les jeux vidéo et 11.1% utilisent les tablettes. 15 élèves dépendant soit 55.6% sont exposés aux images violentes. les compétences scolairesactivités langagière sont plus élevées chez les élèves non dépendant. Les troubles du sommeil, l’impulsivité et l’agressivité seraient plus fréquent chez les élèves dépendant.L’addiction aux écrans chez le jeune enfant a une influence extrêmement large touchant tous les champs de la santé : somatique, cognitive et sociale. Les médecins ont un rôle central d’information et de prévention à jouer lors des consultations auprès des enfants et de leurs familles
Multicentre, prospective, double-blind, randomised controlled clinical trial comparing different non-opioid analgesic combinations with morphine for postoperative analgesia: the OCTOPUS study
BACKGROUND: Head-to-head comparisons of combinations of more than one non-opioid analgesic (NOA) with morphine alone, for postoperative analgesia, are lacking. The objective of this multicentre, randomised, double-blind controlled trial was to compare the morphine-sparing effects of different combinations of three NOAs-paracetamol (P), nefopam (N), and ketoprofen (K)-for postoperative analgesia.
METHODS: Patients from 10 hospitals were randomised to one of eight groups: control (C) received saline as placebo, P, N, K, PN, PK, NK, and PNK. Treatments were given intravenously four times a day during the first 48 h after surgery, and morphine patient-controlled analgesia was used as rescue analgesia. The outcome measures were morphine consumption, pain scores, and morphine-related side-effects evaluated 24 and 48 h after surgery.
RESULTS: Two hundred and thirty-seven patients undergoing a major surgical procedure were included between July 2013 and November 2016. Despite a failure to reach a calculated sample size, 24 h morphine consumption [median (inter-quartile range)] was significantly reduced in the PNK group [5 (1-11) mg] compared with either the C group [27 (11-42) mg; P<0.05] or the N group [21 (12-29) mg; P<0.05]. Results were similar 48 h after surgery. Patients experienced less pain in the PNK group compared with the C, N, and P groups. No difference was observed in the incidence of morphine-related side-effects.
CONCLUSIONS: Combining three NOAs with morphine allows a significant morphine sparing for 48 h after surgery associated with superior analgesia the first 24 h when compared with morphine alone.
CLINICAL TRIAL REGISTRATION: EudraCT: 2012-004219-30; NCT01882530
Jack vertex operators and realization of Jack functions
We give an iterative method to realize general Jack functions from Jack
functions of rectangular shapes. We first show some cases of Stanley's
conjecture on positivity of the Littlewood-Richardson coefficients, and then
use this method to give a new realization of Jack functions. We also show in
general that vectors of products of Jack vertex operators form a basis of
symmetric functions. In particular this gives a new proof of linear
independence for the rectangular and marked rectangular Jack vertex operators.
Thirdly a generalized Frobenius formula for Jack functions was given and was
used to give new evaluation of Dyson integrals and even powers of Vandermonde
determinant.Comment: Expanded versio
Effect of Addition of PET in the Thermal Properties of Polymer-Mortar Composite Materials
The polymer-mortar composites are often used as low-cost promising materials for preventing or repairing various reinforced concrete structures. The Thermal behavior of the ¶building materials ¶is relevant to any use of concrete or composite, especially in relation to structures where it is desirable to have low thermal conductivity, dimensional stability, high specific heat and little or no decrease of stiffness upon heating. Although much work has been done on the effect of admixture and the mechanical properties of concrete or composite, relatively little work has been done on the thermal conductivity. So, Thermal conductivity (l), thermal resistance (R) and the surface coefficients of transmission (U) of polymer-mortar composites made up of mixtures of polyethylene terephthalate PET waste were measured. To determine the effect of the PET on the thermal conductivity of PET-mortar composites, PET was added as replacement for cement by decreasing the cement weights in the ratios of 2.5%, 5% and 7.5% by weight. The highest thermal conductivity of 1.45 W/mK was observed with the samples containing only plain cement. It decreased with the increase of PET as replacement for cement. The lowest value of thermal conductivity and the surface coefficient of transmission were obtained with the samples prepared with PET waste polymer at 7.5 % replacement of cement. The composites were also observed by DTA, MOP led to the positive identification of the products’. In this way, the results obtained highlight the beneficial effect of waste PET as thermal insulation in comparison with other insulation materials. In addition, the obtained PET-mortar composites would appear to be low-cost materials which would contribute to resolving some of the solid waste problems in addition to conserving energy
TUMEUR D’ASKIN. A PROPOS DE HUIT OBSERVATIONS
La tumeur d’Askin est une tumeur neuroectodermique primitive de la région thoracopulmonaire. Elle est rare représentant 6.5% des sarcomes, survenant chez l’enfant et le sujet jeune. Son pronostic est très défavorable ; la survie à 2 ans étant de 38% [1]. Le traitement est basé sur la chimiothérapie néo-adjuvante, suivie d'une chirurgie radicale si possible et/ou d'une irradiation, puis d'une chimiothérapie adjuvante selon la réponse de la tumeur à la chimiothérapie initiale [2,3] .Nous rapportons 8 cas de tumeurs d’Askin traités dans notre service. C’est une étude rétrospective de 8 cas de tumeurs d’Askin colligés au centre d’oncologie Ibn Rochd de Casablanca, durant la période 1998 -2003. Nous rapportons les résultats de notre expérience ainsi qu’une revue de la littérature
Modern insulation materials for warming of walls
Biodiversity hotspots understandably attract considerable conservation attention. However, deserts are rarely viewed as conservation priority areas, due to their relatively low productivity, yet these systems are home to unique species, adapted to harsh and highly variable environments. While global attention has been focused on hotspots, the world's largest tropical desert, the Sahara, has suffered a catastrophic decline in megafauna. Of 14 large vertebrates that have historically occurred in the region, four are now extinct in the wild, including the iconic scimitar-horned oryx (Oryx dammah). The majority has disappeared from more than 90% of their Saharan range, including addax (Addax nasomaculatus), dama gazelle (Nanger dama) and Saharan cheetah (Acinonyx jubatus hecki) - all now on the brink of extinction. Greater conservation support and scientific attention for the region might have helped to avert these catastrophic declines. The Sahara serves as an example of a wider historical neglect of deserts and the human communities who depend on them. The scientific community can make an important contribution to conservation in deserts by establishing baseline information on biodiversity and developing new approaches to sustainable management of desert species and ecosystems. Such approaches must accommodate mobility of both people and wildlife so that they can use resources most efficiently in the face of low and unpredictable rainfall. This is needed to enable governments to deliver on their commitments to halt further degradation of deserts and to improve their status for both biodiversity conservation and human well-being. Only by so-doing will deserts be able to support resilient ecosystems and communities that are best able to adapt to climate change. © 2013 John Wiley & Sons Ltd
The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory
The Photodetector Array Camera and Spectrometer (PACS) is one of the three
science instruments on ESA's far infrared and submillimetre observatory. It
employs two Ge:Ga photoconductor arrays (stressed and unstressed) with 16x25
pixels, each, and two filled silicon bolometer arrays with 16x32 and 32x64
pixels, respectively, to perform integral-field spectroscopy and imaging
photometry in the 60-210\mu\ m wavelength regime. In photometry mode, it
simultaneously images two bands, 60-85\mu\ m or 85-125\mu\m and 125-210\mu\ m,
over a field of view of ~1.75'x3.5', with close to Nyquist beam sampling in
each band. In spectroscopy mode, it images a field of 47"x47", resolved into
5x5 pixels, with an instantaneous spectral coverage of ~1500km/s and a spectral
resolution of ~175km/s. We summarise the design of the instrument, describe
observing modes, calibration, and data analysis methods, and present our
current assessment of the in-orbit performance of the instrument based on the
Performance Verification tests. PACS is fully operational, and the achieved
performance is close to or better than the pre-launch predictions
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