Papers by Keyword: Induction

Abstract: Rapid induction can be utilized to decrease the time and energy used for heat-treatment of steels. In the present study, a commercial 500 HB grade wear-resistant steel was subjected to rapid induction tempering and compared to conventionally furnace tempered samples. The martensitic ultra-high strength steel was cut to narrow thin sheets, which were tempered at 200, 300, 400, and 500 °C with both methods. The rapid tempering was applied with an in-house built induction line, in which the samples were moved through an induction coil. The velocity of the samples was adjusted to ensure constant temperature control. The applied heating rate was 1000–1100 °C/s resulting in extremely rapid tempering times. The conventionally tempered samples were heated in a pre-heated furnace for 45 min and cooled in still air. The samples were tested for tensile and hardness properties and microstructural characterization was conducted. Results revealed only minor differences between the differently treated steels. Elongation was slightly improved with the induction treatment. Therefore, the induction tempering appeared to result in similar or even slightly better tensile properties and can be considered a promising alternative for tempering processes in future steelmaking.

Abstract: Widely used to preserve foods for long-term preservation, freezing is a standard method of preserving food goods. This technique is highly energy-intensive and time-consuming. Utilising shock freezing techniques helps to accelerate the process. The current paper analyses information regarding the technology and application of shock-freezing technologies, including those utilising electromagnetic and electric fields. The results of experiments conducted using a refrigerator equipped with an electromagnetic system are reported. In order to achieve the research objectives, coils were installed in the refrigerator to induce an alternating electromagnetic field with an electromagnetic induction value of up to 0.6 mT. Preliminary experiments were carried out using sodium chloride solutions with various concentrations found in perspective frozen food products.

Abstract: A set of theoretical and experimental studies showing the promising application of devices with the rotating electromagnetic field in the technology of processing sludge wastes of metal production is presented in the paper. Regularities of magneto-vibrational layer formation in those devices and parameters of its energy state control are disclosed. There has also a model of agglomerate destruction in the magneto-vibrational layer been proposed, which establishes a connection of agglomerate particle sizes with the strength of magnetic field induction required for its destruction. The results of studies of the process of ferromagnetic particle grinding are presented, factors affecting the degree of grinding are determined. The possibility of forming an ultradisperse fraction during grinding in the rotating electromagnetic field has been experimentally proved. The effect of porousness on the degree of ferromagnetic particle grinding is shown.

Abstract: The influence of light irradiation with different intensity parameters and different spectral composition on morphogenic structures, namely green zones of cultivar Dolinny cell cultures was investigated. Light irradiation was generated by 10 types of LEDs with different spectra: cold white (Cold W), white (W), warm white (Warm W), Full spectrum, Red, Deep Red, Yellow, Green, Blue and Royal Blue. It was shown that LEDs with Cold W, W and Royal Blue more actively influenced on green zones generation, while Red, Red Deep, Yellow и Green displayed no results. Standard fluorescent lighting illumination (WFL) was used as a control. The number of induced green zones was lower under control luminescent light (WFL) in comparison with the green zones, which were induced by the illumination of the most active spectra of LEDs, but lifetime of these control structures was longer. After 19 weeks of cultivation, degradation of the green zones of the calli was not observed under control and LEDs Cold W, Warm W, and Blue in the position with maximal intensity of light. The Royal Blue illumination displayed the same results not only in the position with maximum intensity but also at the other intensities approaching the control values (49,3 230 μmol/s*m2).

Abstract: The paper considers the study of the electromagnetic force (EMF) of a synchronous generator based on the three-phase induction machine. The stand includes: a frequency converter, an induction motor, a synchronous generator, a three-phase rectifier, an active load resistance, power protection and inclusion industrial electrical network. The study provides an analytical solution to one of the main objectives within theoretical foundations of electrical engineering, formulated so to reflect the decision making while designing new types of synchronous generators with permanent magnets.

Abstract: In induction heating, one is often brought to solve the system of coupled equations:Thermal physical caracteristics (calorific capacity and thermal conductivity.) and electromagnetic (permeability, susceptibility, reluctivity, permittivity, electric conductivity) depend on the temperature for the first, the temperature and the magnetic or electric field for the seconds.The modelisation of the permeability according to the only applied field magnetic abounds in the scientific literature. But, its modelisation as a function of the applied field and also temperature is rather rare.The goal of this work is thus to establish this double modelisation.In this intention, we will use the heat equation, the Maxwell's equations and the function of Brillouin, wich is the physical and formally basis of this modelisation.

Abstract: Objective: To monitor the induction of apoptosis in HT-29 cells by three compounds of oxazinone derivatives (A-C) with similar structures and research the mechanism of those oxazinone derivatives in induction of apoptosis in HT-29 cells. Methods: HT-29 cells were used for the determination of cytotoxicity elicited by oxazinone compounds. Cytotoxic effects of these compounds in HT-29 cells are monitored by a Real-Time Cell Analyser system. Results: All the oxazinone derivatives exhibited growth inhibition in HT-29 cells in a concentration-dependent manner. Conclusion: All the three compounds of oxazinone derivatives (A-C) could exhibit growth inhibition in HT-29 cells in a dose-dependent manner.

Abstract: To find the point of failure of dark line will tend to make electricians helpless, so the design of handheld lighting circuits detector is necessary. This article discribes the main idea of probes inducing the alternating electric field around electricity cables[1]. The collected signal in system is processed through the amplification, filtering, comparison circuit and STC12C5A08AD. Finally, real-time display grid numbers and testing time on 12864. The system’s functions include position detection, discrimination, position records and others. The system can well distinguish different cable. After testing and certification, system is reliable, stable and with practical value.

Abstract: Highly stressed machine parts such as gears and shafts are often surface treated to increase wear and fatigue resistance at critical locations. For example, induction surface hardening (ISH) is increasingly used in the automotive and aerospace industries thanks to the availability of modern multiple frequencies generators and complex shaped coils that provide a great flexibility in process control. With similar end-results in terms of hardened depths, very different residual stress profiles may be obtained, and optimized by modifying both heating and quenching kinetics. If hardness and microstructures variations are routinely verified, some challenges raise for the measurement of the residual stress gradients within complex geometry parts, in particular for the case of deep hardened layers. The most commonly used technique is X-ray diffraction (XRD). It requires using successive layer removal to get access to in-depth stresses. The measurements must therefore be corrected for the stress redistribution occurring during layer removal. However, industrial geometries are often not covered by traditional correction methods. The present work aims at applying XRD to precisely measure in-depth residual stress profiles in induction hardened thin discs made of martensitic steel. Both issues of microstructural variations and redistribution of stresses during layer removal are tackled. First, X-ray elastic constants were determined experimentally using a miniature custom-made tensile machine with specimens heat treated to simulate different microstructures found in ISH parts. Second, a recently introduced finite elements based layer removal correction method was applied. The proposed methodology is used to show the impact of preheating and core hardness on the residual stresses obtained after induction hardening.

Abstract: In computer network communication, adopted the error-check control methods to reduce the error code frequency of data transmission commonly. The CRC (Cyclic Redundancy Check) method is the best one of them. This paper analyzed the principle and the check rules of CRC algorithm. For the CRC algorithm of bytes operation, proposed a new table-driven algorithm which is visual, compact and easy to be understood. A strict mathematic proof of the CRC algorithm is given. By diagrammatizing, deduct the calculated process of CRC-ITU and CRC-32 code in detail. At the same time, we designed a concise CRC-ITU algorithm with assembly language similarly, and discussed the method using the remainder of F(x)/G(x) as a surveillance code briefly.