2,639 research outputs found

    Novel magnetic properties of graphene: Presence of both ferromagnetic and antiferromagnetic features and other aspects

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    Investigations of the magnetic properties of graphenes prepared by different methods reveal that dominant ferromagnetic interactions coexist along with antiferromagnetic interactions in all the samples. Thus, all the graphene samples exhibit room-temperature magnetic hysteresis. The magnetic properties depend on the number of layers and the sample area, small values of both favoring larger magnetization. Molecular charge-transfer affects the magnetic properties of graphene, interaction with a donor molecule such as tetrathiafulvalene having greater effect than an electron-withdrawing molecule such as tetracyanoethyleneComment: 16 pges, 5 figure

    A Smart System for Future Generation based on the Internet of Things Employing Machine Learning, Deep Learning, and Artificial Intelligence : Comprehensive Survey

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    The Internet of Things (IoT) is a networked system including interconnected things, devices, and networks that utilize the internet for communication and data exchange. The entity engages in interactions with both its internal and external surroundings. The IoT is capable of seeing the surrounding environment and responding in a way that is appropriate and adaptive. The utilization of advanced technology in this context enhances the environment and thus enhances the overall well-being of humanity. The IoT facilitates inter-device communication, whether through physical or virtual means. The IoT facilitates the enhancement of environmental intelligence, enabling seamless connectivity across many devices at any given moment. The concepts centred on the IoT, such as augmented reality, high-resolution video streaming, autonomous vehicles, intelligent environments, and electronic healthcare, have become pervasive in contemporary society. These applications have requirements for faster data rates, larger bandwidths, enhanced capacities, decreased latencies, and increased throughputs. IoT and Machine learning (ML) are among the fields of research that have shown significant potential for advancement. ML and IoT are used to build intelligent systems. Those networks will modify the ways in which worldwide entities exchange information. This article gives a comprehensive survey of the upcoming 5G-IoT situation, as well as a study of IoT smart system applications and usages. In addition to covering the latest developments in ML and deep learning (DL) and their impact on 5G-IoT, this article describes a comprehensive study of these important enabling technologies and the developing use cases of 5G-IoT

    Effect of Dissipation, Thermal Radiation, Radiation Absorption on Convective Heat and Mass Transfer Flow in a Non-Uniformly Heated Vertical Channel

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    We analyze the effect of thermal radiation on mixed convective heat and mass transfer flow of a viscous, electrically conducting incompressible fluid through a porous medium in a vertical channel bounded by flat walls. A non-uniform temperature is imposed on the walls and the concentration on these walls is taken to be constant. Assuming the slope δ of the boundary temperature to be small, we solve the governing equations by a perturbation technique. The velocity, the temperature, the concentration, the rate of heat and mass transfer has been analyzed for different variations of the governing parameters. The dissipative effects on the flow, heat and mass transfer are clearly brought out. Keywords: Non-uniform temperature, Porous medium, Thermal Radiation, Radiation Absorption, Dissipatio

    Open Loop Fiber Optic Gyroscope : A Technical Note

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    This technical note describes the design and fabrication of a prototype open-loop interferometric fiber-optic gyroscope (IFOG). The gyro transfer function is transposed from that of a raised-cosine to a sine function using AC modulation, giving maximum sensitivity at rest. Among various signal processing methods, lock-in principle is used to detect the Sagnac phase shift due to rotation. Initial work is done with bulk-optic components. Finally, all-fiber gyroscope is built using laser diode (1300 nm), PINFET detector, fiber couplers and PZT phase modulator. An effort is made to develop compact IFOG with sensing coil diameter of 10 cm and signal processing card of size 10 x 6.5 sq cm. The present set-up is able to detect the direction of rotation at a rotation rate of 5 x 10/sup -4/ radian per second. Presently, the performance of the set-up is limited by the difficulty in achieving complete reciprocity

    Effect of Non-Linear Density Variation on Non-Darcy Convective Heat and Mass Transfer with Newtonian Cooling

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    We investigate the effect of Non-linear density temperature relation on convective heat and mass transfer flow past stretching sheet with Soret and Dufour effects. The Non-linear coupled governing equations have been solved by fourth –order Runge-Kutta method. The velocity, temperature and concentration, skin friction and rate of heat and mass transfer have been discussed for different parametric variations.  We observed that an increase in the density ration γ reduces the velocity, temperature and concentration. Keywords: Heat and Mass transfer, Non-linear temperature relation, Chemical Reaction, Soret and Dufour Effects, Heat sources

    Distribution of Capillary Transit Times in Isolated Lungs of Oxygen-Tolerant Rats

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    Rats pre-exposed to 85% O2 for 5–7 days tolerate the otherwise lethal effects of 100% O2. The objective was to evaluate the effect of rat exposure to 85% O2 for 7 days on lung capillary mean transit time (t¯c) and distribution of capillary transit times (h c(t)). This information is important for subsequent evaluation of the effect of this hyperoxia model on the redox metabolic functions of the pulmonary capillary endothelium. The venous concentration vs. time outflow curves of fluorescein isothiocyanate labeled dextran (FITC-dex), an intravascular indicator, and coenzyme Q1 hydroquinone (CoQ1H2), a compound which rapidly equilibrates between blood and tissue on passage through the pulmonary circulation, were measured following their bolus injection into the pulmonary artery of isolated perfused lungs from rats exposed to room air (normoxic) or 85% O2 for 7 days (hyperoxic). The moments (mean transit time and variance) of the measured FITC-dex and CoQ1H2 outflow curves were determined for each lung, and were then used in a mathematical model [Audi et al. J. Appl. Physiol. 77: 332–351, 1994] to estimate t¯c and the relative dispersion (RDc) of h c(t). Data analysis reveals that exposure to hyperoxia decreases lung t¯c by 42% and increases RDc, a measure h c(t) heterogeneity, by 40%
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