Design And Manufacture Of A Negative Index Metamaterial Using A Magnetized Photonic Crystal

Negative index materials (NIM) are artificial structures in which the refractive index for light has a negative value over some frequency range. This does not occur in any known natural materials, and thus is only achievable with engineered structures known as metamaterials. Metamaterials demonstrating a negative refractive index for light usually consist of arrays of wires and cut-ring structures: such media are characterized by both the electrical permittivity and magnetic permeability being negative. My method for obtaining a NIM is different from previous attempts. I get the negative magnetic permeability from a ferrite material which is the host medium for the wire array. The ferrite plus wires array creates a NIM in the microwave frequency range. One important consideration involves decoupling the ferrite and wire array’s response to incident microwaves. Experiments involving transmission and reflection of microwaves through, and from, a ferrite / wire array metamaterial inside a waveguide demonstrates that ��\u3c0 over a frequency range tunable by adjusting an externally imposed static magnetic field

Traffic light control design approaches: a systematic literature review

To assess different approaches to traffic light control design, a systematic literature review was conducted, covering publications from 2006 to 2020. The review’s aim was to gather and examine all studies that looked at road traffic and congestion issues. As well, it aims to extract and analyze protruding techniques from selected research articles in order to provide researchers and practitioners with recommendations and solutions. The research approach has placed a strong emphasis on planning, performing the analysis, and reporting the results. According to the results of the study, there has yet to be developed a specific design that senses road traffic and provides intelligent solutions. Dynamic time intervals, learning capability, emergency priority management, and intelligent functionality are all missing from the conventional design approach. While learning skills in the adaptive self-organization strategy were missed. Nonetheless, the vast majority of intelligent design approach papers lacked intelligent fear tires and learning abilities

A new algorithm to enhance security against cyber threats for internet of things application

One major problem is detecting the unsuitability of traffic caused by a distributed  denial of services (DDoS) attack produced by third party nodes, such as smart phones and other handheld Wi-Fi devices. During the transmission between the devices, there are rising in the number of cyber attacks on systems by using negligible packets, which lead to suspension of the services between source and destination, and can find the vulnerabilities on the network. These vulnerable issues have led to a reduction in the reliability of networks and a reduction in consumer confidence. In this paper, we will introduce a new algorithm called rout attack with detection algorithm (RAWD) to reduce the affect of any attack by checking the packet injection, and to avoid number of cyber attacks being received by the destination and transferred through a determined path or alternative path based on the problem. The proposed algorithm will forward the real time traffic to the required destination from a new alternative backup path which is computed by it before the attacked occurred. The results have showed an improvement when the attack occurred and the alternative path has used to make sure the continuity of receiving the data to the main destination without any affection

Mitigation and control of electric fields on spacers' surfaces in gas insulated systems

Research in the area of gas insulated systems' (GIS) reliability is still attracting a considerable attention from the electric utilities and the scientific community in many countries. Solid insulating spacers in GIS represent the weakest points in these systems, and several troubles and systems' outages have been reported allover the world due to their failure. So it is essential to determine the electric field distribution along their surfaces and hence evaluate the degree of their reliability. Several researchers evaluated the electric field distribution on the spacers' surfaces in gas insulated systems and studied the effects of their dimensions and its relative permittivity on the electric field stress distribution. The outcome of these investigations is that the electric field stresses intensify around the triple junction and they are the main reason to initiate breakdown in gas insulated systems. Due to the previously mentioned spacers' troubles, they should be precisely designed to realize more or less uniform field distribution along their surfaces. The spacer's profile is considered the main variable, which controls the field distribution and hence field uniformity can be achieved by adopting the appropriate profile. This paper uses the artificial neural network technique "ANN" to optimize the electric field on the spacer's surface, and introduces a novel method based on replacing the spacer's material with a constant permittivity by another one having a functionally graded permittivity to optimize and control the electric field along its surface. The use of the ANN enabled the authors to design a spacer with a pre-selected almost uniform field along its surface. The error between the target field and the evaluated one is ± 5%. Also the use of FGM reduced the electric field near the triple junction at the enclosure to les than 50% in some cases

Social Finance and Financing Social Enterprises: An Islamic Finance Prospective

Enterprises that have a dual objective of generating positive social impact and financial economic benefit turned to be vital with the increased level of poverty and other major social problems accompanied with limited public spending. The growth and development of social impact enterprises is fundamental for all economies and financing them is a challenging issue where they struggle to accessing finance. Traditional financial instruments are difficult to access especially after the recent financial crisis due to that social enterprises face high risk regarding generating profit, problems of governance model, and lacks of performance measurement valuations especially when it comes to measuring social value. On the other hand, Islamic finance has experienced progressive growth in the last years and could play significant role not only limited to Muslims but also for Non-Muslim countries. Advances in Islamic Finance and Social Finance demonstrate an increasing global attention for finding alternative ways of financing and creating value in the society since both of them have similar ethical dictates. Sharia that regulates all Islamic financial instruments and investments and its screening methodology prohibits unethical businesses and practices that are similar to the negative screening methodology adopted by the socially responsible investment which make both of them connected to Social Finance. This paper is exploratory in nature and argues that Islamic finance could be a viable potential alternative with its diversified instruments for financing social impact enterprises. The paper provides insights for researchers, decision makers, and practitioners of how Islamic finance provide valid financing tools for social finance through mobilizing private funds allocated from investors who seeks investments that generate both social and economic value

Social Finance And Unconventional Financing Alternatives: An Overview

The economic crisis, the increment of poverty and unemployment, the emergence of several social problems, and the limitations of the public spending have all called for exploring innovative and alternative ways of social financing. Such enterprises face many challenges in accessing finance due to that high risk regarding generating profit, problems of governance model, and lacks of performance measurement valuations especially when it comes to measuring social value. There is a need for finance impact driven businesses and this requires the reinforcement of current funding alternatives and usage of innovative financing alternatives. Islamic finance with its unconventional wide range instruments represents a possible potentiality for offering innovative financing alternative. The paper is exploratory and should give insights to the emerging interest in both social impact finance and Islamic finance with its innovative tools that focus on risk sharing and social impact. This paper argues that unconventional financing alternatives could positively impact international economies and be a viable potential alternative for financing with its diversified instruments for social enterprises development. The paper explores the different unconventional instruments of financing as well as the criteria of accessing them. The paper provides insights for researchers, decision makers, and practitioners of how could be unconventional financing used as valid financing tool for social impact businesses

Subtle Right Ventricular Affection in Patients with Acute Myocardial Infarction, Echocardiographic Assessment

BACKGROUND: The right ventricle (RV) has historically received less attention than its counterpart of the left side of the heart, yet there is a substantial body of evidence showing that RV size and function are perhaps equally important in predicting adverse outcomes in cardiovascular diseases. AIM: The aim of our work was to evaluate incidence and impact of right ventricular (RV) affection in patients with acute left ventricular myocardial infarction subjected to primary percutaneous coronary intervention (1ry PCI). METHODS: The study was conducted on 80 patients who had acute left ventricle ST elevated myocardial infarction (LV STEMI) and subjected to 1ry PCI. The study was done in Cairo University, critical care department. All patients were studied within 2 days after 1ry PCI, RV function was assessed by echocardiography through tricuspid annular plane systolic excursion (TAPSE) and speckle tracking echocardiography. We excluded patients with RV infarction, moderate to severe tricuspid regurgitation, pulmonary hypertension, dilated cardiomyopathy, atrial or ventricular septal defect, and patients who had cardiac dysrhythmias. RESULTS: Out of 80 patients (64 men and 16 women) included in the study, 38 patients (47.5%) had TAPSE <1.7 cm, and 48 patients (60%) had RV longitudinal strain less negative than −19%.There was a statistically significant relationship between RV affection and anterior STEMI, left anterior descending artery as an infarct-related artery, duration of intensive care unit stay, impairment of LV global and regional systolic function, in-hospital complications, and 1-year mortality. CONCLUSION: RV dysfunction is not uncommon in acute LV STEMI when using the definition of TAPSE <17 cm and RV longitudinal strain less negative than −19%.There was a significant relationship between RV dysfunction and poor outcome in patients with acute LV STEMI