58 research outputs found

    Tunability of terahertz random lasers with temperature based on superconducting materials

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    We theoretically demonstrate the tunabiltiy of terahertz random lasers composed of high temperature superconductorYBCO and ruby layers as active medium. The considered system is a one-dimensional disordered medium made of ruby grain and YBCO. Finite-difference time domain method is used to calculate the emission spectrum and spatial distribution of electric field at different temperatures. Our numerical results reveal that the superconductor based random lasers exhibit large temperature tunability in the terahertz domain. The emission spectrum is significantly temperature dependent, the number of lasing modes and their intensities increase with decreasing temperature. Also, we make some discussion to explain the reason for the observed tunability and the effect of temperature variation on the spatial distribution of the electric field in the disordered active medium

    Analysis of stakeholder roles and the challenges of solar energy utilization in Iran

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    Growing energy demand, rising greenhouse gas emissions and the depletion of fossil fuels necessitates the development of renewable energy sources. In order to improve renewable energy utilization, it is necessary to determine the most important factors influencing energy strategy. The energy system of Iran is highly dependent on fossil fuels; however, Iran has a high potential for solar energy development and several policies are being pursued by the government to develop power generation by renewable energy resources. This study presents and discusses several important parameters of energy policy and security which make the installation of photovoltaic (PV) systems crucial for the future. Installation of solar PV will improve energy security, foster job creation and reduce environmental problems. It also introduces and investigates those institutions and organizations involved in developing renewable energies, especially solar energy. These include the Ministry of Energy and universities, both of which play key roles in the development of solar energy.fi=vertaisarvioitu|en=peerReviewed

    The Effect of Family Empowerment Model on Quality of Life in Children with Epilepsy in South of Iran, 2018: A Randomized Controlled Clinical Trial

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    Abstract Objectives:Epilepsy is a chronic disease of the nervous system that significantly affects the performance and behavior of children. Epileptic children are at greater risk of cognitive and behavioral disorders than healthy children. Various factors associated with this disease affect the patients’ family. Materials & Methods:The present study is a randomized controlled clinical trial conducted to evaluate the effect of family empowerment on quality of life of epileptic children referred to the desired centers (Bessat Clinic affiliated to Kerman University of Medical Sciences and Imam Reza Clinic of Shiraz) in two experimental and control groups. 80 parents of these children were selected and studied, if they met the inclusion criteria of study. In this study, Quality of Life in Childhood Epilepsy Questionnaire (QOLCE) was used. It is completed by parents of these children. Results:The age of the studied children was 4 to 8 yrs. According to these results, there was a statistically significant difference between the two groups in the level of changes in all dimensions, so that the mean score of quality of life in different factors increased in the experimental group compared to the control group (P <0.05 in all dimensions). Conclusion:Implementing the family-centered care plan by care providers, based on patient-family support relationships, identifying their strengths and weaknesses, prioritizing the services provided, and an effective interaction with the health team increase the family and staff satisfaction, reduce the costs, and improve the outcome of the disease. &nbsp

    Comparison of ECC and RSA algorithms in IOT devices

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    IoT is the evolution of the internet. Concerning tight communication between the individual and business, number of IoT nodes are rapidly increasing. Most of the services in IoT heavily rely on security mechanisms that pose security imperative for embedded devices in IoT. The failures in IoT can have severe results; consequently, the research toward security concerns are of extreme significance in IoT. Preserving the confidentiality and privacy, ensuring the availability of the services that are proposed by IoT ecosystem, assuring the safety of the assets in IoT like devices, data, infrastructures, and users, are the main objectives in IoT security. The significant issue that makes IoT devices vulnerable is the lack of an appropriate security mechanism to preserve data. Attackers can exploit these weaknesses to obtain access to valuable data. Hence, thoughtfully chosen and practically tested encryption algorithm must be performed to enhance the device efficiency and decrease the risk of sensitive data exposure. Understanding and comparing algorithms implemented in IoT devices, regarding performance discussed in this paper. RSA (Rivest Shamir Adleman) and ECC (Elliptic Curve Cryptography) algorithms have been compared for identifying the most lightweight, secure, efficient implementation in IoT. Based on the findings, the ECC algorithm outperforms RSA in a constrained environment in terms of memory requirements, energy consumption, key sizes, signature generation time, key generation and execution time, and decryption time while RSA performs better in verifying the signature and encrypting

    Nanostructured multifunctional stimuli-responsive glycopolypeptide-based copolymers for biomedical applications

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    Inspired by natural resources, such as peptides and carbohydrates, glycopolypeptide biopolymer has recently emerged as a new form of biopolymer being recruited in various biomedical applications. Glycopolypeptides with well-defined secondary structures and pendant glycosides on the polypeptide backbone have sparked lots of research interest and they have an innate ability to self-assemble in diverse structures. The nanostructures of glycopolypeptides have also opened up new perspectives in biomedical applications due to their stable three-dimensional structures, high drug loading efficiency, excellent biocompatibility, and biodegradability. Although the development of glycopolypeptide-based nanocarriers is well-studied, their clinical translation is still limited. The present review highlights the preparation and characterization strategies related to glycopolypeptides-based copolymers, followed by a comprehensive discussion on their biomedical applications with a specific focus on drug delivery by various stimuli-responsive (e.g., pH, redox, conduction, and sugar) nanostructures, as well as their beneficial usage in diagnosis and regenerative medicine.Peer reviewe
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