A review for solar panel fire accident prevention in large-scale PV applications

Due to the wide applications of solar photovoltaic (PV) technology, safe operation and maintenance of the installed solar panels become more critical as there are potential menaces such as hot spot effects and DC arcs, which may cause fire accidents to the solar panels. In order to minimize the risks of fire accidents in large scale applications of solar panels, this review focuses on the latest techniques for reducing hot spot effects and DC arcs. The risk mitigation solutions mainly focus on two aspects: structure reconfiguration and faulty diagnosis algorithm. The first is to reduce the hot spot effect by adjusting the space between two PV modules in a PV array or relocate some PV modules. The second is to detect the DC arc fault before it causes fire. There are three types of arc detection techniques, including physical analysis, neural network analysis, and wavelet detection analysis. Through these detection methods, the faulty PV cells can be found in a timely manner thereby reducing the risk of PV fire. Based on the review, some precautions to prevent solar panel related fire accidents in large-scale solar PV plants that are located adjacent to residential and commercial areas

A Novel Synthetic Analog of 5, 8-Disubstituted Quinazolines Blocks Mitosis and Induces Apoptosis of Tumor Cells by Inhibiting Microtubule Polymerization

Many mitosis inhibitors are powerful anticancer drugs. Tremendous efforts have been made to identify new anti-mitosis compounds for developing more effective and less toxic anti-cancer drugs. We have identified LJK-11, a synthetic analog of 5, 8-disubstituted quinazolines, as a novel mitotic blocker. LJK-11 inhibited growth and induced apoptosis of many different types of tumor cells. It prevented mitotic spindle formation and arrested cells at early phase of mitosis. Detailed in vitro analysis demonstrated that LJK-11 inhibited microtubule polymerization. In addition, LJK-11 had synergistic effect with another microtubule inhibitor colchicine on blocking mitosis, but not with vinblastine or nocodazole. Therefore, LJK-11 represents a novel anti-microtubule structure. Understanding the function and mechanism of LJK-11 will help us to better understand the action of anti-microtubule agents and to design better anti-cancer drugs

Intelligent Permanent Magnet Motor-Based Servo Drive System Used for Automated Tuning of Piano

This paper presents an intelligent permanent magnet synchronous motor-based servo drive system used in automated piano tuning applications. The permanent magnet synchronous motor-based drives are able to improve the accuracy of the piano tuning process in comparison with the traditional direct-current motor-based and step motor-based servo drives. To explain the techniques, firstly, the structure and principles of the automated piano tuning devices with a surface-mounted permanent magnet synchronous motor-based drive system integrated are introduced, illustrating that it is feasible to implement the proposed piano tuning strategy. Secondly, the piano tuning devices have two functions: low-speed rotation and position holding. To ensure that the surface-mounted permanent magnet synchronous motor can rotate stably over the low-speed range with strong anti-interference capacity, a double closed-loop speed-regulation-based control scheme is employed. And to ensure high position control performance, a fuzzy-adaptive triple closed-loop position-regulation-based control scheme is employed. It terms of the control schemes, it deserves to be mentioned that main contributions include, firstly, the parameters of the proportional integral controllers in the double closed-loop speed-regulation structure is tuned relying on both stability and bandwidth analyses. Then, a fuzzy-adaptive proportional integral controller is specially-designed for the triple closed-loop position-regulation to adapt to the piano tuning applications. Simulation is conducted on a 20 rpm three-phase permanent magnet synchronous motor servo drive-based piano tuning system to validate the proposed piano tuning method and to verify the proposed control techniques

Fast Dynamic Translation Using LLVM On Multi-Core Hosts

International audienceIn the development of embedded systems, Instruction-Set Simulators (ISS) plays an important role. When using an ISS, simulation speed is a significant issue. In this paper, we present experiments and comparison between several dynamic translation techniques. In addition to an existing technique which serves as a reference, we have developed a new on-the-fly translation technique using the LLVM open-source compiler infrastructure to enhance simulation speed. This dynamic translation technique translates hot basic blocks of the target instruction set into LLVM bitcode, then compiles LLVM bitcode into host binary code using the LLVM Just-In-Time (JIT) compiler. As the translation time using LLVM increases to the detriment of the overall simulation speed, we also present a mixed mode, where only the frequently executed chunks of code are compiled. This translation technique was then extended to support larger translation units compared to the previous, Finally the paper ends with presentation of an orthogonal solution to dispatch dynamic translation to a translation server to take advantage of multi-processor hosts

Research Progress in Ordered Nanomaterials via Magnetic Field Induced Preparation

Ordered nanomaterials are widely concerned for their excellent performance in mechanics, electricity, optics and magnetism. Magnetic field induced self-assembly is widely used for the preparation of ordered nanomaterials, which has the advantages of indirect contact with the reaction system, controllable adjustment of magnetic field. By using this preparation method, it can realize the alignment of nanomaterials without affecting the comprehensive performance of each component in the system. In this paper, we reviewed magnetic field induced self-assembly of metal nanomaterials, oxide nanomaterials and nanocomposites. We also looked forward to the future research direction

Research progress of preservative coating of natural polymer materials

The planting area and output of fruits and vegetables in China are the first in the world. However, due to the imperfection of storage and transportation fresh-keeping technology, the annual loss of fruits and vegetables in China is serious. Rational use of fresh-keeping coating is of great significance for improving the shelf life of fruits and vegetables. Natural polymer preservative coating is widely concerned in the field of fruits and vegetables due to its wide sources, degradability, low price and good film-forming ability. In this paper, the types of natural polymer preservative coating were reviewed, and its application in the freshkeeping of fruits and vegetables was summarized and prospected, so as to provide Reference for further research

Chemical structure of LJK-11.

<p>Chemical structure of LJK-11.</p