Effect of Radio-Frequency Treatment on the Changes of Dissolved Organic Matter in Rainwater

Rainwater is a potential source of drinking water, but has various components of dissolved organic matter (DOM). DOM is a reservoir of potential hazards in drinking water. Therefore, a new method is required to purify rainwater as a drinking water source in terms of DOM aspects. A radio-frequency (RF) treatment system is introduced here to purify source water with a small possibility of contamination. RF is generated by applying a frequency of 1.5 MHz through a glass reactor with a diameter of 2 mm which is wrapped by a 2 mm copper wire. The results demonstrate that UV260 value and dissolved organic carbon (DOC) are reduced during RF treatment. DOC was reduced by a lower amount compared to UV260, suggesting the partial transformation of bio-refractory DOM. A fluorescence excitation-emission matrix showed that humic-like substances in rainwater were reduced faster than protein-like ones, indicating that humic-like substances are susceptible to reduction by RF treatment. The results offer information on the use of RF treatment in a rainwater purification process for the production of drinking water.

Высокотемпературная сверхпроводниковая магнитная система для изучения нейронной активности

The paper describes a high-temperature superconducting magnetic system (HTS SMS) to equip an experimental stand intended for neuron activity researches under constant and low-frequency magnetic fields up to 1 T. The design of the magnetic system together with its electromagnetic and cryogenic parameters is briefly discussed. The test results of the preliminary experiments conducted in liquid nitrogen at 77 K for two interchangeable magnets are given. The first magnet was manufactured in the form of a double pancake coil wound with 4 mm high HTS tape. The second magnet was made of pure copper wire with no frame and was impregnated with a thermally conducting epoxy resin. The advantages of the HTS pancake coil were demonstrated in comparison with the cryo-resistive solenoid. Low energy consumption of the HTS magnetic system will allow conducting continuous non-invasive monitoring of biological objects in a magnetic field.

Silver Nanoparticulate Matter Reinforced Conducting Polymer Polyaniline Nanocomposite: Sol-Gel Processing, Schottky-Diode Making and Electronic Worthiness Testing

Polyaniline nanoparticles is synthesized by chemical oxidation of aniline by copper sulphate. Chemical reduction of silver nitrate by sodium citrate yileds silver nanoparticles. Both aforesaid nanomaterials are mixded with polyvinyl alcohol to get nanocomposite gel. Nanoparticles are characterized by ultraviolet-visible absorption spectroscopy. Schottky diode is made by applying nanocomposite with copper wire on one side of aluminium foil and on other side attaching copper wire for another electrical contact. Current-voltage electrical characterization is analyzed by making simple circuit encompassing polyaniline/silver nanocomposite diode. Keywords: Nanoelecttronics, Nanoparticles, Polyaniline, Nanocomposite, Schottky-diode

On the Optimal Selection of Flux Barrier Reconfiguration for a Five-Phase Permanent Magnet Assisted Synchronous Reluctance Machine for Low-Torque Ripple Application

This paper aims to investigate the reconfigurations of rotor flux barriers for a five-phase Permanent Magnet Assisted Synchronous Reluctance Machine (PMASynRM). To precisely study the performance of the proposed configurations, a conventional PMASynRM with double-layer flux barriers is included in the study. Since the novel rotor schemes consume the same amount of rare-earth magnets, steel sheet materials, and copper wire, resulting in no extra manufacturing costs, the optimal reconfiguration should be determined, providing developed electromagnetic characteristics. Thus, all the proposed models are designed and analyzed under the same condition. The Lumped Parameter Model (LPM) is exported to the Finite Element Method (FEM) for precise analysis to reach developed torque and lower values of torque ripple. Based on the FEM results the model presenting the lowest torque fluctuations is selected as the optimal model and dynamically investigated. According to the results, in comparison with the conventional model, the introduced rotor designs provide a much lower value of torque fluctuations with a desirable amount of electromagnetic torque and power. In addition, the optimal model presents high values of power factor and efficiency, making it a vital alternative for low-torque ripple high-speed operations with no extra cost to the implementation process.

On the Use of Carbon Cables from Plastic Solvent Combinations of Polystyrene and Toluene in Carbon Nanotube Synthesis

For every three people on the planet, there are approximately two Tonnes (Te) of plastic waste. We show that carbon recovery from polystyrene (PS) plastic is enhanced by the coaddition of solvents to grow carbon nanotubes (CNTs) by liquid injection chemical vapour deposition. Polystyrene was loaded up to 4 wt% in toluene and heated to 780 °C in the presence of a ferrocene catalyst and a hydrogen/argon carrier gas at a 1:19 ratio. High resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Raman spectroscopy were used to identify multiwalled carbon nanotubes (MWCNTs). The PS addition in the range from 0 to 4 wt% showed improved quality and CNT homogeneity; Raman “Graphitic/Defective” (G/D) values increased from 1.9 to 2.3; mean CNT diameters increased from 43.0 to 49.2 nm; and maximum CNT yield increased from 11.37% to 14.31%. Since both the CNT diameters and the percentage yield increased following the addition of polystyrene, we conclude that carbon from PS contributes to the carbon within the MWCNTs. The electrical contact resistance of acid-washed Bucky papers produced from each loading ranged from 2.2 to 4.4 Ohm, with no direct correlation to PS loading. Due to this narrow range, materials with different loadings were mixed to create the six wires of an Ethernet cable and tested using iPerf3; the cable achieved up- and down- link speeds of ~99.5 Mbps, i.e., comparable to Cu wire with the same dimensions (~99.5 Mbps). The lifecycle assessment (LCA) of CNT wire production was compared to copper wire production for a use case in a Boeing 747-400 over the lifespan of the aircraft. Due to their lightweight nature, the CNT wires decreased the CO2 footprint by 21 kTonnes (kTe) over the aircraft’s lifespan.

A Study on the Development of Carbon Fiber with Electromagnetic Wave Shielding Performance and Sizing Removal State Measurement Algorithm Using Image Processing

In this paper, nickel-plated carbon fiber was fabricated by a dry process method to improve electromagnetic wave shielding performance. In general, carbon fiber is wrapped in a polymer type in manufacturing and is used after removing the sizing in the pretreatment step for dry coating. The existing sizing removal method was used by removing only with a solution or only with compressed air. In this paper, the method of solution and compressed air (hybrid) was added. The state in which the sizing was removed was determined only by the know-how of the experienced person, and in this paper, it is proposed to represent the numerical value by applying the image processing surface analysis technique. As a result, it was possible to numerically indicate that the hybrid method was excellent among the sizing removal methods and it was possible to manufacture the nickel-plated carbon fibers (30 μm, 40 μm, and 100 μm) by a roll-to-roll sputtering method on the sizing-removed spreading carbon fiber roll. The electromagnetic wave shielding performance of 100 nickel-coated carbon fiber measured by the Korea Testing Laboratory showed the highest electromagnetic wave shielding performance from 66.7 (dB) to 73.2 (dB). This is similar to the electromagnetic wave shielding rate of copper, so it can be used as a cable for EV/HEV vehicles, and it is expected to have a great effect of improving the bending characteristics and disconnection phenomenon and improving the lifespan compared to the existing copper wire.

CALCULATION OF ELECTROTHERMAL PROCESSES IN THE INDUCTION CHANNEL FURNACE IN THE STEADY-STATE OPERATION BASED ON THE THEORY OF THERMAL CIRCUITS

Based on the theory of thermal circuits, a computer model of an induction channel furnace has been developed, which is used to obtain industrial copper wire rods in the mode of continuous casting. The model allows calculating the established electrothermal processes considering the flows of cold and molten metal in its core. In the developed thermal model, it is proposed to consider the convection fluxes of heat in the metal using controlled current sources. The temperature distribution in the active zone of the channel furnace is calculated, and the influence of the mass flow of metal at the inlet and outlet of the furnace on the non-uniformity of temperature distribution in the active zone is shown. The obtained results allow determining the required electric power of the furnace at different values ​​of the flow rate of the metal that moves continuously through its core while heating to a given temperature. The developed model is relatively easy to implement, using the Matlab/Simulink package, and allows online to estimate the melt temperature in different zones depending on the electric power consumed by the furnace and the metal consumption at the outlet of the furnace, as well as to determine rational modes of its operation. Ref. 7, fig. 4.

Technical Analysis and Identification of a Glass Inlaid Sui-Tang Dynasty Woman’s Crown

A woman’s crown made of fine gilt bronze with refined glass inlay work was excavated in 2007 from the Sui-Tang tomb called Kunlun M2 in Xi’an. Many questions surround this mysterious crown which was found buried without context. This study uses nondestructive analysis of the crown to determine its significance, when was it made, and the status of the woman for whom was it made. Optical microscopy (OM), optical coherence tomography (OCT), micro X-ray fluorescence imagery (XRF), and Raman spectroscopy were applied, and identified the crown’s inlays as potash-lime glass, composed mainly of the raw materials include vein quartz or quartzite with potassium nitrate as flux. The inlays were sintered before embedding into gilt copper wire filigree. Compared with existing research on other crowns and their inlays, it is speculated that the crown dates from the Sui dynasty (581-618) or early Tang dynasty (618-649), was made locally by Chinese craftsmen and belonged to the wife of an official.