883 research outputs found

    Insecticidal activity of four medicinal plant extracts against Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

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    Methanol extracts from four medicinal plants, Peganum harmala (Zygophyllaceae), Ajuga iva (Labiateae), Aristolochia baetica (Aristolochiaceae) and Raphanus raphanistrum (Brassicaceae) werestudied for their insecticidal effects on the stored grain pest Tribolium castaneum (Herbst). Response varied with plant species. Larvae growth was significantly inhibited when they were fed with extracts incorporated into the diet. Good insecticidal activity against T. castaneum larvae and adults wasachieved with extract of P. harmala seeds, followed by extract of A. iva, Ari. baetica and R. raphanistrum aerial parts. The extracts of the four plants disrupted the developmental cycle of the insect. Extracts of P. harmala, A. iva and Ari. baetica inhibited F1 progeny production. These naturally occurring plant extracts could be useful for managing populations of T. castaneu

    Efficient method for transformer models implementation in distribution load flow matrix

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    Introduction. Most distribution networks are unbalanced and therefore require a specific solution for load flow. There are many works on the subject in the literature, but they mainly focus on simple network configurations. Among the methods dedicated to this problem, one can refer to the load flow method based on the bus injection to branch current and branch current to bus voltage matrices. Problem. Although this method is regarded as simple and complete, its drawback is the difficulty in supporting the transformer model as well as its winding connection types. Nevertheless, the method requires the system per unit to derive the load flow solution. Goal. In the present paper, our concern is the implementation of distribution transformers in the modeling and calculation of load flow in unbalanced networks. Methodology. Unlike previous method, distribution transformer model is introduced in the topology matrices without simplifying assumptions. Particularly, topology matrices were modified to take into account all winding types of both primary and secondary sides of transformer that conserve the equivalent scheme of an ideal transformer in series with an impedance. In addition, the adopted transformer models overcome the singularity problem that can be encountered when switching from the primary to the secondary side of transformer and inversely. Practical value. The proposed approach was applied to various distribution networks such as IEEE 4-nodes, IEEE 13-nodes and IEEE 37-nodes. The obtained results validate the method and show its effectiveness.Вступ. Більшість розподільчих мереж незбалансовані і тому потребують спеціального рішення для потоку навантаження. У літературі є багато робіт на цю тему, але переважно вони присвячені простим мережевим конфігураціям. Серед методів, присвячених цій проблемі, можна назвати метод потоку навантаження, заснований на введенні шини в матрицю струму відгалуження і відгалуження струму в матрицю напруги шини. Проблема. Хоча цей метод вважається простим та повним, його недоліком є складність підтримки моделі трансформатора, а також типів з’єднання його обмоток. Проте метод вимагає системи на одиницю для отримання рішення про потік навантаження. Мета. У цій статті нас цікавить застосування розподільних трансформаторів для моделювання та розрахунку потоку навантаження у незбалансованих мережах. Методологія. На відміну від попереднього методу, модель розподільного трансформатора вводиться в матриці топології без спрощення припущень. Зокрема, матриці топології були змінені, щоб врахувати всі типи обмоток як первинної, так і вторинної сторін трансформатора, які зберігають еквівалентну схему послідовно ідеально включеного трансформатора з імпедансом. Крім того, прийняті моделі трансформаторів долають проблему сингулярності, з якою можна зіткнутися при перемиканні з первинної на вторинну обмотку трансформатора і навпаки. Практична цінність. Пропонований підхід був застосований до різних розподільних мереж, таких як IEEE з 4 вузлами, IEEE з 13 вузлами та IEEE з 37 вузлами. Отримані результати підтверджують метод та показують його ефективність

    COMPARATIVE ANALYZES OF ICG-VA, DIVA, FLOW 800 IMAGING IN CEREBROVASCULAR SURGERY

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    It is the most important to visualize cerebral vessels along with its surrounding structures during cerebrovascular surgery and it can be easier with real-time angiographic imaging. There are different kinds of indocyanine green dye based videoangiography are commonly used in cerebrovascular surgery. The objective. Comparative analyzing of ICG-AG, DIVA and Flow 800 color mapping in cerebrovascular surgery. Materials and methods. Real time surgery assessment of vascular and surrounding structures in 29 cerebral aneurysms clipping, one STA-MCA bypass and 2 carotid artery endarterectomy had been performed using ICG-VA, DIVA, flow 800 color mapping from August to October 2019. Result. In 23 cases in cerebral aneurysms clipping ICG-VA could not clearly visualize perforators compared to its’ better visualization by DIVA. In 3 cases, occlusion of perforators were assessed by DIVA after clip application which was solved by reapplication of surgical clips. In one STA-MCA bypass surgery, patency and sequences of blood inflow to cortical branches of MCA (M4) from recently anastomosed STA branches were assessed with ICG-VA, DIVA and Flow 800 color mapping. Visualization of the lack of blood flow and fluttering atherosclerotic plaques in carotid endarterectomy was observed by ICG-VA, DIVA, flow 800 mapping. Conclusion. In real time cerebrovascular surgery, ICG-VA, DIVA, and Flow 800 color mapping can be effective tool to better visualization of vascular and surrounding structures. Benefits of flow 800 color mapping outweighs the advantages of both ICG-VA and DIVA. However, DIVA is also better than ICG-VA to visualize

    Effects of plant hormones and 20-hydroxyecdysone on tomato (Lycopersicum esculentum) seed germination and seedlings growth

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    20-hydroxyecdysone (20E) is the major phytoecdysteroid of about 6% of plants. Its role in plant physiology has not been fully elucidated. In this work we studied the effects of 20E application on somemorphological and biochemical parameters of tomato, Lycopersicum esculentum, seed during germination and seedling development (5 d). We compared the 20E effects with the action of phytohormones: gibberellic acid (GA3), naftalen acetic acid (NAA), benzyl amino purine (BAP). NAA treatment resulted in marked reduction in shoot length. GA3 treatment promoted maximal shoot elongation. BAP affected negatively shoot length only at late stages, while 20E application stimulated shoot elongation at early stages and reduced it on the fifth day; NAA inhibited root elongation all along the test period. GA3 treatment had no effect on root length, whereas BAP showed strong inhibition on root elongation. On the other hand, 20E showed a weak inhibition of root elongation on the fifth day. As compared to control and to other treatments, NAA and 20E provoked a drastic decrease in protein contents during seedling growth, whereas a high increase was observed under BAP treatment. Electrophoresis revealed that protein bands were not degraded and mobilized after NAA treatmentwhile in control or after 20E and others phytohormones applications, protein patters displayed weak band intensities and some of them were not detected. NAA, GA3 and BAP provoked a decrease inproline content during seedlings, while the effect of 20E on proline levels varied during germination and plantlet development. This work showed that 20E like phytohormones fulfil some bioactive actionsduring germination and seedlings growth in tomato

    MOCVD growth of Bi2Te3-Sb2Te3 layers : Effect of growth parameters on the electrical and thermoelectrical properties

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    The growth of (Bi1-xSbx)2Te3 thin films by metal-organic chemical vapour deposition (MOCVD) using trimethylbismuth, triethylantimony and diethyltellurium as bismuth, antimony and tellurium sources respectively is investigated on pyrex substrates. The electrical and thermoelectrical properties of this material are also measured over the growth temperature range 360-470°C. The studies are also made on the effect of VI/V ratio on these properties in the variation range 2-9. Polycrystalline structure is confirmed by X-ray diffraction, and it is observed that the intensity of the preferred orientation is higher at 450°C. The measurement of Seebeck coefficient shows that all samples have p-type conduction. The best value of this parameter is obtained for high growth temperature (240µV/K). The good result obtained for (Bi1-xSbx)2Te3 thin films revealed the great potential of MOCVD method which is an industrial technique to produce good materials for device applications (sensors and thermopiles).The growth of (Bi1-xSbx)2Te3 thin films by metal-organic chemical vapour deposition (MOCVD) using trimethylbismuth, triethylantimony and diethyltellurium as bismuth, antimony and tellurium sources respectively is investigated on pyrex substrates. The electrical and thermoelectrical properties of this material are also measured over the growth temperature range 360-470°C. The studies are also made on the effect of VI/V ratio on these properties in the variation range 2-9. Polycrystalline structure is confirmed by X-ray diffraction, and it is observed that the intensity of the preferred orientation is higher at 450°C. The measurement of Seebeck coefficient shows that all samples have p-type conduction. The best value of this parameter is obtained for high growth temperature (240µV/K). The good result obtained for (Bi1-xSbx)2Te3 thin films revealed the great potential of MOCVD method which is an industrial technique to produce good materials for device applications (sensors and thermopiles)

    Fistule carotido-caverneuse post-traumatique

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    Introduction : La fistule carotido-caverneuse (FCC) est une complication rare, mais grave des traumatismes craniofaciaux pouvant engager le pronostic fonctionnel oculaire et le pronostic vital. elle réalise une communication anormale entre le système artériel carotidien et le sinus caverneux.Buts : Rapporter un cas de FCC directe post-traumatique et étudier les aspects cliniques, diagnostiques et thérapeutiques de cette pathologie.Observation : Nous rapportons un cas de FCC apparue dans les suites d’un traumatisme craniofacial et survenue chez un homme de 25 ans ayant été victime d’un accident de la voie publique. Le diagnostic a été suspecté devant l’apparition, au 19ème jour d’hospitalisation, d’une exophtalmie unilatérale gauche pulsatile associée à un important chémosis et à une pupille aréflectique. Une artériographie cérébrale pratiquée 9 jours après la constatation de l’exophtalmie a objectivé une large FCC gauche. Une embolisation au moyen de deux ballonnets intravasculaires largables et de l’injection de colle biologique a été réalisée au même temps sans incidents permettant d’obtenir l’occlusion complète de la fistule. L’évolution a été marquée par la régression de l’exophtalmie et du chémosis et par l’amélioration partielle de l’acuité visuelle.Conclusion : Le traitement des FCC est urgent et est principalement basé sur la neuroradiologie interventionnelle. en effet, l’angiographie cérébrale constitue l’examen clé et possède un double intérêt diagnostique et thérapeutique.Mots clés : fistule carotido-caverneuse, traumatisme craniofacial, artériographie cérébrale, embolisation

    Product assurance technology for procuring reliable, radiation-hard, custom LSI/VLSI electronics

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    Advanced measurement methods using microelectronic test chips are described. These chips are intended to be used in acquiring the data needed to qualify Application Specific Integrated Circuits (ASIC's) for space use. Efforts were focused on developing the technology for obtaining custom IC's from CMOS/bulk silicon foundries. A series of test chips were developed: a parametric test strip, a fault chip, a set of reliability chips, and the CRRES (Combined Release and Radiation Effects Satellite) chip, a test circuit for monitoring space radiation effects. The technical accomplishments of the effort include: (1) development of a fault chip that contains a set of test structures used to evaluate the density of various process-induced defects; (2) development of new test structures and testing techniques for measuring gate-oxide capacitance, gate-overlap capacitance, and propagation delay; (3) development of a set of reliability chips that are used to evaluate failure mechanisms in CMOS/bulk: interconnect and contact electromigration and time-dependent dielectric breakdown; (4) development of MOSFET parameter extraction procedures for evaluating subthreshold characteristics; (5) evaluation of test chips and test strips on the second CRRES wafer run; (6) two dedicated fabrication runs for the CRRES chip flight parts; and (7) publication of two papers: one on the split-cross bridge resistor and another on asymmetrical SRAM (static random access memory) cells for single-event upset analysis

    End-of-fabrication CMOS process monitor

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    A set of test 'modules' for verifying the quality of a complementary metal oxide semiconductor (CMOS) process at the end of the wafer fabrication is documented. By electrical testing of specific structures, over thirty parameters are collected characterizing interconnects, dielectrics, contacts, transistors, and inverters. Each test module contains a specification of its purpose, the layout of the test structure, the test procedures, the data reduction algorithms, and exemplary results obtained from 3-, 2-, or 1.6-micrometer CMOS/bulk processes. The document is intended to establish standard process qualification procedures for Application Specific Integrated Circuits (ASIC's)
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