A new operational matrix based on Bernoulli polynomials

In this research, the Bernoulli polynomials are introduced. The properties of these polynomials are employed to construct the operational matrices of integration together with the derivative and product. These properties are then utilized to transform the differential equation to a matrix equation which corresponds to a system of algebraic equations with unknown Bernoulli coefficients. This method can be used for many problems such as differential equations, integral equations and so on. Numerical examples show the method is computationally simple and also illustrate the efficiency and accuracy of the method

Heterogeneous wireless networks for smart grid distribution systems: Advantages and limitations

Supporting a conventional power grid with advanced communication capabilities is a cornerstone to transferring it to a smart grid. A reliable communication infrastructure with a high throughput can lay the foundation towards the ultimate objective of a fully automated power grid with self-healing capabilities. In order to realize this objective, the communication infrastructure of a power distribution network needs to be extended to cover all substations including medium/low voltage ones. This shall enable information exchange among substations for a variety of system automation purposes with a low latency that suits time critical applications. This paper proposes the integration of two heterogeneous wireless technologies (such as WiFi and cellular 3G/4G) to provide reliable and fast communication among primary and secondary distribution substations. This integration allows the transmission of different data packets (not packet replicas) over two radio interfaces, making these interfaces act like a one data pipe. Thus, the paper investigates the applicability and effectiveness of employing heterogeneous wireless networks (HWNs) in achieving the desired reliability and timeliness requirements of future smart grids. We study the performance of HWNs in a realistic scenario under different data transfer loads and packet loss ratios. Our findings reveal that HWNs can be a viable data transfer option for smart grids. 2018 by the authors. Licensee MDPI, Basel, Switzerland.Acknowledgments: This work was made possible by the United Arab Emirates University UPAR Grant No. 31N226.Scopu

Effects of the Ferrits Addition on the Properties of Polyethylene Terephthalate

يلعب الحشو دورًا رئيسيًا في تحديد خصائص وسلوك المواد المتراكبة للمنتج. في هذه الدراسة ، تم تحضير وودراسه خصائص   متراكبات PET  المضاف اليه ZnFe2O4. العمل يتضمن اعداد عينات من البولي إيثيلين تيريفثاليت (PET) / الزنك - الفريت (ZnFe2O4) بنسب إضافات مختلفة مثل الزنك - الفريت (1 ، 2 ، 5 ، 10 ، 15 و 20) وزن% عن طريق الحصول عليه من خلط المحلول بطريقه الضغط الساخن والمطبقة تحت الظروف المثلى. تم حساب كثافة جميع النماذج. تمت دراسة الخصائص التركيبية باستخدام نمط حيود الأشعة السينية XRD ، وأظهرت نتائج تحليل حيود XRD أن هيكل PET النقي هو متعـدد التبلور، هناك أربعـــة قمـم عريضة عنـد (2θ=16.46°,17.45°, 22.72°,25.98° ) والمركب الخزفي ذات طور بلوري ذو بنية مكعبة مع ثوابت شبيكه وذات مجموعة فضائية fd-3m (227) ((a=b=c=8.44 A° و (V = 601.45 (A°)³)  أثناء إضافة الزنك-الفريت إلى PET بتركيزات مختلفة للحصول على مادة (PET / ZnFe2O4) انتج مواد تزداد فيها كثافة الشدّة وتغير موقع القمم مع زيادة إضافة الزنك-الفريت ، وتجدر الإشارة أنماط الحيود لـ PET / ZnFe2O4 (20٪) تشير إلى أنه لم يكن هناك اختلاف واضح في أنماط حيود Zn-ferrite النقي الذي أظهر أن التركيب البلوري يبقى ثابتًا في PET / ZnFe2O4. بالإضافة إلى ذلك ، فإن الخصائص الكهربائية للمتراكبات ممثلة بواسطة ثابت العزل الكهربائي ، فقد تم قياس خسارة العزل الكهربائي وموصلية التيار المتناوب كدالة لمجموعة من الترددات (50 هرتز -1 ميجاهرتز) ، وأوضحت النتائج أن هذه الخصائص تزداد مع زيادة تركيز السيراميك المضاف. و تقل هذه الخواص بزيادة التردد بسبب التغير في آليات الاستقطاب ، وقد ثبت أن هذه المواد المتراكبة المحضرة تمتلك خصائص ذات استقرار جيد في نطاق واسع من الترددات ، مما يجعل هذه التراكبات البوليمرية ذات استخدام واسع في العديد من التطبيقات. أما بالنسبة لقياسات صلادة Shore D ، فقد تبين القياسات صلادة هذا المتراكب تزداد مع زيادة تراكيز السيراميك.The products of composites material are very sesetive to many variables, such as manufacturing process, additive materials, …. etc. Filler or additive plays a major role to determine the formation of the properties and behavior of the composites. In this study, polyethylene terephthalate-based compounds were produced and characterized. The work is concerned to prepare samples of Polyethylene terephthalate (PET) - zinc-ferrite (ZnFe2O4) with different addition ratio as zinc-ferrite (1, 2, 5, 10, 15 and 20) wt% obtained from mixing the solution with a hot pressing method applied under optimum conditions. The densities of the composites for all samples were calculated. Through the work the diffusion of zinc-ferrite into the grain of Polyethylene terephthalate has been noted.  Structural properties are studied by using X-ray powder pattern, the results of the XRD diffraction analysis showed that the structure for pure PET has four broad peaks at the (2θ=16.46°,17.45°, 22.72°,25.98°). The non-crystalline behavior of the polymer and the ceramic compound indicates the presence of a crystalline phase with a single cubic structure with a space group fd-3m (227)) (a=b=c=8.44 Å, V=601.45 (Å)³). While adding zinc-ferrite to PET in different concentrations to obtain (PET / ZnFe2O4) composites material will increase the intensity of the X-ray peaks, and change the location of the peaks with the addition of zinc-ferrite. It is noted that X-ray diffraction patterns for PET / ZnFe2O4 (20%) indicates that there was no apparent variation of the patterns of pure Zn-ferrite ceramic diffraction which showed that the crystalline structure remains stable in PET / ZnFe2O4. In addition, the electrical properties of the compounds represented by the dielectric constant (real and imaginary), dielectric loss ( tanδ) and the A.C conductivity as a function of a range of frequencies (50Hz-1MHz) have been measured. The results indicated that these properties increase with increasing concentrations of ceramic addition. On the other hand, these properties decrease with increasing frequency due to the change in polarization mechanisms. It has been proven that these prepared superposed materials possess good stability properties in a wide range of frequencies, making these polymeric overlays of wide use in many applications. As for the measurements of Shore D hardness, it has been shown that the hardness of the compounds increases with increasing ceramic concentrations

How to scrutinise a Production Sharing Agreement: A guide for the oil and gas sector based on experience from the Caspian region

This guide discusses the provisions of a particular type of oil and gas contract, the Production Sharing Agreement (PSA). While the guide is aimed at a general civil society readership, it draws particularly on experience from Kazakhstan. The purpose of this guide is to give an accessible account of some key characteristics of PSAs, with a focus on revenue issues, and to suggest action points for civil society organisations involved with monitoring extractive industries. Indeed, in recent years the public in resource-rich states has become increasingly concerned about the management of extractive industry revenues

Assessment of linear-scale indices for perimetry in terms of progression in early glaucoma

AbstractCurrently, global indices that summarize the visual field combine sensitivities on a logarithmic (decibel) scale. Recent structure–function models for glaucoma suggest that contrast sensitivity should be converted to a linear scale before averaging across visual field locations, to better relate sensitivity with the number of surviving retinal ganglion cells (RGCs). New indices designed to represent the number of RGCs already lost are described. At least one was found to be a significantly better predictor of subsequent rate of change than traditional Mean Deviation (p=0.014) in participants with glaucomatous optic neuropathy. Issues concerning the creation of optimal global indices are discussed

Human pathogen shown to cause disease in the threatened elkhorn coral Acropora palmata

Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS), a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments were conducted with A. palmata maintained in closed aquaria to determine infectivity of strain PDR60 from reef and wastewater sources. Strain PDR60 from wastewater and diseased A. palmata caused disease signs in elkhorn coral in as little as four and five days, respectively, demonstrating that wastewater is a definitive source of APS and identifying human strain PDR60 as a coral pathogen through fulfillment of Koch\u27s postulates. A. palmata inoculated with strain PDR60 from C. abbreviata showed limited virulence, with one of three inoculated fragments developing APS signs within 13 days. Strain PDR60 from non-host coral S. siderea showed a delayed pathogenic effect, with disease signs developing within an average of 20 days. These results suggest that C. abbreviata and non-host corals may function as reservoirs or vectors of the APS pathogen. Our results provide the first example of a marine “reverse zoonosis” involving the transmission of a human pathogen (S. marcescens) to a marine invertebrate (A. palmata). These findings underscore the interaction between public health practices and environmental health indices such as coral reef survival

Human Pathogen Shown to Cause Disease in the Threatened Elkhorn Coral Acropora palmata

Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS), a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments were conducted with A. palmata maintained in closed aquaria to determine infectivity of strain PDR60 from reef and wastewater sources. Strain PDR60 from wastewater and diseased A. palmata caused disease signs in elkhorn coral in as little as four and five days, respectively, demonstrating that wastewater is a definitive source of APS and identifying human strain PDR60 as a coral pathogen through fulfillment of Koch\u27s postulates. A. palmata inoculated with strain PDR60 from C. abbreviata showed limited virulence, with one of three inoculated fragments developing APS signs within 13 days. Strain PDR60 from non-host coral S. siderea showed a delayed pathogenic effect, with disease signs developing within an average of 20 days. These results suggest that C. abbreviata and non-host corals may function as reservoirs or vectors of the APS pathogen. Our results provide the first example of a marine \u27\u27reverse zoonosis\u27\u27 involving the transmission of a human pathogen (S. marcescens) to a marine invertebrate (A. palmata). These findings underscore the interaction between public health practices and environmental health indices such as coral reef survival

Data-driven curation, learning and analysis for inferring evolving IoT botnets in the wild

The insecurity of the Internet-of-Things (IoT) paradigm continues to wreak havoc in consumer and critical infrastructure realms. Several challenges impede addressing IoT security at large, including, the lack of IoT-centric data that can be collected, analyzed and correlated, due to the highly heterogeneous nature of such devices and their widespread deployments in Internet-wide environments. To this end, this paper explores macroscopic, passive empirical data to shed light on this evolving threat phenomena. This not only aims at classifying and inferring Internet-scale compromised IoT devices by solely observing such one-way network traffic, but also endeavors to uncover, track and report on orchestrated "in the wild" IoT botnets. Initially, to prepare the effective utilization of such data, a novel probabilistic model is designed and developed to cleanse such traffic from noise samples (i.e., misconfiguration traffic). Subsequently, several shallow and deep learning models are evaluated to ultimately design and develop a multi-window convolution neural network trained on active and passive measurements to accurately identify compromised IoT devices. Consequently, to infer orchestrated and unsolicited activities that have been generated by well-coordinated IoT botnets, hierarchical agglomerative clustering is deployed by scrutinizing a set of innovative and efficient network feature sets. By analyzing 3.6 TB of recent darknet traffic, the proposed approach uncovers a momentous 440,000 compromised IoT devices and generates evidence-based artifacts related to 350 IoT botnets. While some of these detected botnets refer to previously documented campaigns such as the Hide and Seek, Hajime and Fbot, other events illustrate evolving threats such as those with cryptojacking capabilities and those that are targeting industrial control system communication and control services

Nasal Airway Obstruction and the Quality of Life

The objective of this study was to estimate the prevalence of nasal airway  obstruction among patients attending the dental clinic of Ajman University of Science & Technology (AUST) (Fujairah Campus/UAE) and how it affects their quality of life. A sample of 100 patients attending the dental clinic of (AUST) was examined for nasal obstruction. Demographic data, history taking, along with patient assessment of nasal obstruction with a nasal speculum and radiographs, were recorded. Quality of life (QOL) was assessed using a questionnaire.The subjects 58% males and 42% females were 10-59 years old. 34% of the patients have nasal obstruction and 15% had history of trauma to the nose. 28% have difficulty in breathing through their nose. Nasal septal deviation accounted for the majority of the cases 94.1%. Nasal obstruction is a precipitating factor of quality of life, 61.7% of the patients were reported to have mild obstruction, 17% moderate obstruction and 2.9% severe obstruction. The study showed that 52% have habitual snoring and the effect of posture was reported to be 8.8%.