The world is highly interested in using solar energy as an alternative to fossil energy. Changing the shape of solar systems was adopted to improve its work efficiency. Although the solar tracker is ...made to be more efficient than the fixed solar system, the work to develop it is yet uncompleted. In this paper, the solar tracker system is used, which works by (LDR) sensors, microcontroller Arduino UNO for controlling the system, and DC motors. The extent of the impact of the solar tracker was studied with its work time. The worked electric circuit for the timer was run the system for one minute and shut-down the system circuit for 29 minutes, the comparison of the work of the tracker was done with a timer and without timer. Finally, according to the amount of gain and loss of energy, it was found that the energy gains about 96.25% from timer system only, and the lost energy from the solar panel because used the timer is about (0.238 to 0.475) % only. The workplace lies in (32o01'49.08" N, 44o22'21.83" E, in Iraq), in August, to real solar panel type.
We numerically study transport phenomena in a superconducting detector. Our approach is to simulate the three-dimensional time-dependent Ginzburg-Landau equation coupled with heat-diffusion and ...Maxwell equations. The simulation shows dynamical transition to a resistive state when an incident particle has energy higher than superconducting transition temperature. We show temporal behaviors of a superconducting gap function, depending on the incident energy scale. Furthermore, we discuss the applicability of our method to a superconducting single-photon detector. Focusing on the effects of coupling with heat sink and magnitude of quasi-particle fluctuations, we show a significant decrease of detector's threshold energy.
Most studies on granular physics have focused on dry granular media, with no liquids between the grains. However, in geology and many real world applications (e.g. food processing, pharmaceuticals, ...ceramics, civil engineering, construction, and many industrial applications), liquid is present between the grains. This produces inter-grain cohesion and drastically modifies the mechanical properties of the granular media (e.g. the surface angle can be larger than 90 degrees). Here we present a review of the mechanical properties of wet granular media, with particular emphasis on the effect of cohesion. We also list several open problems that might motivate future studies in this exciting but mostly unexplored field.
Collocated adaptive control of underactuated mechanical systems is still a concern for the control community. The main difficulty comes from the nonlinearity of the collocated inverse dynamics with ...respect to the base parameters, which forbids the direct application of classical adaptive control schemes. This paper extends and encompasses the Slotine's adaptive control, which was developed for fully actuated mechanical systems, to stabilize the collocated state space of an underactuated mechanical system. The key point is to define the sliding variable as the difference between the system's velocity and an exogenous state whose dynamics is considered as control input. We first revisit the Slotine's result in view of this definition and then show how to extend it to the underactuated case. Stability and convergence of time-varying reference trajectories for the collocated dynamics are shown to be in the sense of Lyapunov. Global well-posedness of the control laws is achieved by means of a new algebraic property of the mass matrix. Simulations, comparisons to existing control strategies, and experimental results on a two-link manipulator verify the soundness of the proposed approach.
Abstract
The research works on designing and manufacturing a device that can generate clean energy, taking into account the geographical location of Iraq, and be economical and cheap, this ...manufactured device addresses the permanent problems that this type of device encounters. Therefore, a solar tracker has been manufactured that tracks the sun’s rays, to reduce the number of solar panels used, and is an environmentally friendly generator, it works without the LDR photosensors. The work was done on different days, a sunny day, a partially cloudy day, and a cloudy day. Through the work, it was practically observed that the device responded to work and reduced the problem of dispersion, as it was directed by programming from the microcontroller, not by the sensors, from the obtained results, it was noted that the generation losses in the three days under study sequentially are (10.9%, 9%, 4.9% ) and the results are very acceptable, and the anticipated outcome was attained.
The populations of energy levels of interacting qubits have been studied as functions of the field amplitude and other control parameters for a constant frequency of the external electromagnetic ...field. It has been found that the qubit coupling constant strongly affects the quantum-coherent Landau-Zener transitions between the qubit states and the formation of an interference pattern in level populations, depending on the field parameters. It has been demonstrated that it is possible to determine the qubit coupling constant by Landau-Zener interferometry.
The study of the impact of noise on quantum circuits is especially relevant to guide the progress of Noisy Intermediate-Scale Quantum (NISQ) computing. In this paper, we address the pulse-level ...simulation of noisy quantum circuits with the Quantum Toolbox in Python (QuTiP). We introduce new tools in
qutip-qip
, QuTiP's quantum information processing package. These tools simulate quantum circuits at the pulse level, leveraging QuTiP's quantum dynamics solvers and control optimization features. We show how quantum circuits can be compiled on simulated processors, with control pulses acting on a target Hamiltonian that describes the unitary evolution of the physical qubits. Various types of noise can be introduced based on the physical model, e.g., by simulating the Lindblad density-matrix dynamics or Monte Carlo quantum trajectories. In particular, the user can define environment-induced decoherence at the processor level and include noise simulation at the level of control pulses. We illustrate how the Deutsch-Jozsa algorithm is compiled and executed on a superconducting-qubit-based processor, on a spin-chain-based processor and using control optimization algorithms. We also show how to easily reproduce experimental results on cross-talk noise in an ion-based processor, and how a Ramsey experiment can be modeled with Lindblad dynamics. Finally, we illustrate how to integrate these features with other software frameworks.
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