549 research outputs found

    Computational Analysis of the Optical and Charge Transport Properties of Ultrasonic Spray Pyrolysis-Grown Zinc Oxide/Graphene Hybrid Structures

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    We demonstrate a systematic computational analysis of the measured optical and charge transport properties of the spray pyrolysis-grown ZnO nanostructures, i.e. nanosphere clusters (NSCs), nanorods (NRs) and nanowires (NWs) for the first time. The calculated absorbance spectra based on the time-dependent density functional theory (TD-DFT) shows very close similarity with the measured behaviours under UV light. The atomic models and energy level diagrams for the grown nanostructures were developed and discussed to explain the structural defects and band gap. The induced stresses in the lattices of ZnO NSCs that formed during the pyrolysis process seem to cause the narrowing of the gap between the energy levels. ZnO NWs and NRs show homogeneous distribution of the LUMO and HOMO orbitals all over the entire heterostructure. Such distribution contributes to the reduction of the band gap down to 2.8 eV, which has been confirmed to be in a good agreement with the experimental results. ZnO NWs and NRs exhibited better emission behaviours under the UV excitation as compared to ZnO NSCs and thin film as their visible range emissions are strongly quenched. Based on the electrochemical impedance measurement, the electrical models and electrostatic potential maps were developed to calculate the electron lifetime and to explain the mobility or diffusion behaviours in the grown nanostructure, respectively

    Coincidence of Fixed Points with Mixed Monotone Property

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                  الغرض من هذا البحث استعراض واثبات النقاط الصامدة الثنائية للدوال الذاتية التي تحقق الشرط  مع التعابير النسبية في الفضاءات المترية الكاملة  المرتبة جزئيا والتي تتضمن دوال المسافة بخاصية ال (MP). تعمل النتائج التي حصلنا عليها على تحسين وتوحيد العديد من النتائج في مبرهنات النقطة الصامدة الثنائية وتعميم بعض النتائج الحديثة في الفضاء المتري المرتب جزئيا. تم إعطاء مثال لاظهار صحة نتيجتنا الرئيسية .The purpose of this paper is to introduce and prove some coupled coincidence fixed point theorems for self mappings satisfying -contractive condition with rational expressions on complete partially ordered metric spaces involving altering distance functions with mixed monotone property of the mapping. Our results improve and unify a multitude of coupled fixed point theorems and generalize some recent results in partially ordered metric space. An example is given to show the validity of our main result.

    Decision support system based on BWM for Analyzing success factors affecting the quality in the Iraqi construction projects

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    Creating a balance between cost, time, and quality in construction projects is always expected. It is possible to have a project with excellent quality and minimal cost, but at the expense of time, or vice versa. The goal of this paper is to discover, evaluate and prioritize the factors that most influence the desired construction projects' level of quality (success factors) in Iraq. Over a comprehensive review of literature, 11 potential quality-related factors were found to fall into the following five categories: client, contractor, design, materials, and project related factors. These factors' significance was determined using fuzzy Best Worst Method (BWM). Result shows the most three significant success factors influencing quality in the construction projects were related to contractor, client, and designer. These factors were financial competence of contractor, technical capability of client, and designer suitable selection with weights (30.84%, 15.58%, and 10.05%) respectively. These results conclude that maximization of the success factors will guarantee that the building sector achieves its quality objectives

    Comparative study of the downtowns of Topeka, Kansas and Lincoln, Nebraska

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    Call number: LD2668 .R4 ARCH 1988 N37Master of ArchitectureArchitectur

    Cyclic Self-Organizing Map for Object Recognition

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    Object recognition is an important machine learning (ML) application. To have a robust ML application, we need three major steps: (1) preprocessing (i.e. preparing the data for the ML algorithms); (2) using appropriate segmentation and feature extraction algorithms to abstract the core features data and (3) applying feature classification or feature recognition algorithms. The quality of the ML algorithm depends on a good representation of the data. Data representation requires the extraction of features with an appropriate learning rate. Learning rate influences how the algorithm will learn about the data or how the data will be processed and treated. Generally, this parameter is found on a trial-and-error basis and scholars sometimes set it to be constant. This paper presents a new optimization technique for object recognition problems called Cyclic-SOM by accelerating the learning process of the self-organizing map (SOM) using a non-constant learning rate. SOM uses the Euclidean distance to measure the similarity between the inputs and the features maps. Our algorithm considers image correlation using mean absolute difference instead of traditional Euclidean distance. It uses cyclical learning rates to get high performance with a better recognition rate. Cyclic-SOM possesses the following merits: (1) it accelerates the learning process and eliminates the need to experimentally find the best values and schedule for the learning rates; (2) it offers one form of improvement in both results and training; (3) it requires no manual tuning of the learning rate and appears robust to noisy gradient information, different model architecture choices, various data modalities and selection of hyper-parameters and (4) it shows promising results compared to other methods on different datasets. Three wide benchmark databases illustrate the efficiency of the proposed technique: AHD Base for Arabic digits, MNIST for English digits, and CMU-PIE for faces

    Fabrication of Lateral Polysilicon Gap of Less than 50nm Using Conventional Lithography

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    We report a thermal oxidation process for the fabrication of nanogaps of less than 50 nmin dimension.Nanogaps of this dimension are necessary to eliminate contributions from double-layer capacitance in the dielectric detection of protein or nucleic acid. The method combines conventional photolithography and pattern-size reduction techniques. The gaps are fabricated on polysiliconcoated silicon substrate with gold electrodes. The dimensions of the structure are determined by scanning electron microscopy (SEM). An electrical characterization of the structures by dielectric analyzer (DA) shows an improved conductivity as well as enhanced permittivity and capacity with the reduction of gap size, suggesting its potential applications in the detection of biomolecule with very low level of power supply. Two chrome Masks are used to complete the work: the first Mask is for the nanogap pattern and the second one is for the electrodes. An improved resolution of pattern size is obtained by controlling the oxidation time. The method expected to enable fabrication of nanogaps with a wide ranging designs and dimensions on different substrates. It is a simple and cost-effective method and does not require complicated nanolithography process for fabricating desired nanogaps in a reproducible fashion

    An academic perspective of assessment questions bank

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    There are several electronic assessment systems being used in institutions of higher education (HE), especially in Open and Distance Learning (ODL) institutions. Some of these institutions built their assessment system into their institution’s Virtual Learning Environments (VLE). Most of these assessment systems are for general purposes where assessment questions are in the form of simple multiple choice question (MCQ) or short-answer questions. In practice, these types of assessment questions do not match many of the current learning requirements and learning outcomes. The concept of an assessment question bank that can be used by academics to share assessment content within or across an institution is not new, but the advancement of technology and technical developments now have made such a repository realizable than ever before. A question bank is now a specialized repository that can be accessed via a web interface for platform independence. The use of technology in developing the question bank provides much relief for the chores associated with preparing assessments, which in turn enhances the quality of the questions and improves the quality of the assessments. This paper presents the experience of Open University Malaysia (OUM) in developing its own Question Bank (QBank). This QBank system is designed to help the Subject Matter Experts (SMEs) who need to develop, classify and store their assessment such as MCQ and essay-type exam questions. This software is integrated with the OUM’s Virtual Learning Environments (myVLE) in order to allow easier and wider access to the SMEs and faculty. (Abstract by author

    Error correction and uncertainty measurement of short-open-load calibration standards on a new concept of software defined instrumentation for microwave network analysis

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    Software-Defined Radio (SDR) has appeared as a sufficient framework for the development and testing of the measurement systems such as a signal generator, signal analyzer, and network analysis used in the network analyzer. However, most of researchers or scientists still rely on commercial analyzers were larger benchtop instruments, highly cost investment and minimum software intervention. In this paper, a new concepts measurement revolution called as Software Defined Instrumentation (SDI) on network analysis is presented, which is based on reconfigurable SDR, a low-cost implementation, ability to access RF chain and utilizing open source signal processing framework. As a result, a Vector Network Analyzer (VNA) has been successful implemented by deploying an SDR platform, test sets, and data acquisition from the GNU Radio software in host PC. The known calibration process on SHORT-OPEN-LOAD (SOL) technique is validated to ensure measurement data from this SDI free from systematic error. Two types of SOL calibration standards used for a comparison study to validate the SDI measurement system which is capable of generating the response on the differential of standard quality and accuracy of standards kits. Finally, calibration uncertainty analysis is also presented in this work by utilizing RF open source package without any cost addition

    Protection of smart substation based on WLAN complies with IEC61850 using traveling wave analysis

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    Fast protection of distribution substation based on traveling wave is becoming a reality today. The transient traveling wave is mostly used in protection to determine the faulted line and the fault location. The advantages of signal of traveling wave includes immunity to system oscillation, transition resistance, CT saturation, and neutral point operation modes. In this article, a detailed study for analyzing the performance of using WLAN for real time protection based on the transient traveling wave. The high sampling frequency needed for traveling wave causes blockage in communication in the process bus. Now a packing of multi samples with suitable compression techniques in Merging Unit (MU), or using feature extraction with Hilbert–Huang transform with WLAN compliance with IEC 61850 has been tested. Further, this article presents the modeling and simulation of a WLAN communication network for an automation system using the precepts of IEC 61850, which is currently becoming a trend in Substation Automation System (SAS) specification. This article also investigates the impact of impulsive and interface noise on WLAN performance. Finally, the article advocates the wide application of traveling waves in the digital substations based on the IEC 61850 protocol

    Role of Antiviral Drugs in Management of Mild and Moderate Coronavirus Disease-19: A Systematic Review

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    This study was conducted to determine the objective role of antiviral drugs such as arbidol, lopinavir/ritonavir, and others in improving clinical symptoms, decreasing duration of hospitalization, and decreasing duration of viral shedding in patients with mild and moderate COVID-19 infection. A systematic literature search was carried out on Google Scholar and PubMed databases, using the keywords “COVID-19”, “Antiviral”, “Treatment”, and “Symptomatic” in various combinations. Observational studies, cohort and case control studies, and clinical trials published in English with full-text available were included in the study. Data extraction was carried out from selected studies, and all statistical analysis for the study was carried out using Microsoft Excel. The key outcomes studied were time to negative PCR, duration of clinical stay, time to clinical improvement, and occurrence of adverse events. Seven studies were selected for final review after rigorous selection process. Data of total 4734 participants was analyzed, the majority of which were females (n=2810, 59.3%). The majority of participants had mild disease (n=4197, 88.65%). Average time for negative RT-PCR in the included treatment groups was 13.5 days, whereas the average duration of hospitalization was 14.9 days for the treatment groups. Adverse reactions such as ECG changes, gastrointestinal symptoms, secondary bacterial infections, and hepatic and renal dysfunction were scarcely reported in the included studies. There is no clear benefit in terms of duration of hospitalization and time to negative PCR with the use of various antiviral regimens in mild disease; however, these drugs did play a role in limiting disease progression in the participant population. Pending further evidence, the use of these drugs for the management of COVID-19 is not recommend in patients with mild disease
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