610 research outputs found
High Temperature Method Of Measuring Electrical And Magnetic Properties Of Europium Doped Nickel Oxide
The measurement of the magnetic moment of materials as a function of temperature in
modern AC or DC magnetometers normally has a limited high temperature range up
to 400 K. To overcome this problem one needs to design ovens which can handle high
temperatures. The highest Curie temperature observed in materials is in pure Co which is
about 1400 K. However, most materials and compounds show Tc below 800 K. My thesis
research topic is to study the substitution of Ni ions by rare earth ions in NiO. The
NiO is a semiconductor which exhibits antiferromagnetism below 520 K, which makes
it suitable for applications; to name a few, rechargeable batteries, and p-type transport
conducting lms. In this study, Ni ions were substituted by 2, 5, and 8 percent of Eu ions.
The effect of substitution on the semiconducting properties of Ni1-xEuxO was studied
as function of temperature from room temperature to 1000 K. To study the magnetic
properties and the effect of Eu substitution on the Neel temperature of Ni1-xEuxO we
adapted two ovens for high temperature measurements of AC susceptibility by using the
ac modulation technique implementing a lock-in ampli er and the DC susceptibility using
the SQUID magnetometer. To check the reliability of these two ovens we also examined
the ferromagnetic transition temperatures of Bismuth Ferrite samples as function of Co
substitutions for Fe
A Review of Systemic Biologics and Local Immunosuppressive Medications in Uveitis
Uveitis is one of the most common causes of vision loss and blindness worldwide. Local and/or systemic immunosuppression is often required to treat ocular inflammation in noninfectious uveitis. An understanding of safety and efficacy of these medications is required to individualize treatment to each patient to ensure compliance and achieve the best outcome. In this article, we reviewed the effectiveness of systemic biologic response modifiers and local treatments commonly used in the management of patients with noninfectious uveitis
A CSI-based Human Activity Recognition using Canny Edge Detector
Human Activity Recognition (HAR) is one of the hot topics in the field of human-computer interaction. It has a wide variety of applications in different tasks such as health rehabilitation, smart houses, smart grids, robotics, and human action prediction. HAR can be carried out through different approaches such as vision-based, sensor-based, radar-based, and Wi-Fi-based. Due to the ubiquitous and easyto-deploy characteristic of Wi-Fi devices, Wi-Fi-based HAR has gained the interest of both academia and industry in recent years.WiFi-based HAR can be implemented by two channel metrics: Channel State Information (CSI) and Received Signal Strength Indicator (RSSI). Recently, converting the CSI data to images has led to increasing the accuracy level of activity prediction. However, none of the previous research has focused on extracting the features of converted images using image-processing techniques. In this study, we investigate three available datasets, gathered using CSI property, and took advantage of Deep Learning (DL), with convolutional layers and edge detection technique to increase overall system accuracy. The canny edge detector extracts the most important features of the image, and giving it to the DL
model empowers the prediction of activities. In all three datasets, we witnessed an improvement of 5%, 27%, and 37% in terms of accuracy
Andreev Reflection without Fermi surface alignment in High T-Topological heterostructures
We address the controversy over the proximity effect between topological
materials and high T superconductors. Junctions are produced between
BiSrCaCuO and materials with different Fermi
surfaces (BiTe \& graphite). Both cases reveal tunneling spectra
consistent with Andreev reflection. This is confirmed by magnetic field that
shifts features via the Doppler effect. This is modeled with a single parameter
that accounts for tunneling into a screening supercurrent. Thus the tunneling
involves Cooper pairs crossing the heterostructure, showing the Fermi surface
mis-match does not hinder the ability to form transparent interfaces, which is
accounted for by the extended Brillouin zone and different lattice symmetries
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Theory and Implementation of a Variational Database Management System
In this thesis, I present the variational database management system, a formal framework and its implementation for representing variation in relational databases and managing variational information needs. A variational database is intended to support any kind of variation in a database. Specific kinds of variation in databases have already been studied and are well-supported, for example, schema evolution systems address the variation of a database’s schema over time and data integration systems address variation caused by accessing data from multiple data sources simultaneously. However, many other kinds of variation in databases arise in practice, and different kinds of variation often interact, but these scenarios are not well-supported by the existing work. For example, neither the schema evolution systems nor the database integration systems can address variation that arises when data sources combined in one database evolve over time.
This thesis collects a large amount of work: It defines the variational database framework and the syntax and denotational semantics of the variational relational algebra, a query language for variational databases. It presents two use cases of the variational database framework that are based on existing datasets and scenarios that are partially supported by existing techniques. It presents the variational database management system which is a prototype of variational databases and variational relational algebra as an abstract layer written in Haskell on top of a traditional RDBMS. It also presents several theoretical results related to the framework and the query language, such as syntax-based equivalence rules that preserve the semantics of a query, a type system for ensuring that a variational query is well-formed with respect to the underlying variational schema, and a confluence property of the variational relational algebra type system with respect to the relational algebra type system and its denotational semantics
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