Fundamentals of Inductively Coupled Wireless Power Transfer Systems

The objective of this chapter is to study the fundamentals and operating principles of inductively coupled wireless power transfer (ICWPT) systems. This new technology can be used in various wireless power transfer applications with different specifications, necessities, and restrictions such as in electric vehicles and consumer electronics. A typical ICWPT system involves a loosely coupled magnetic coupling structure and power electronics circuitries as an integrated system. In this chapter, the emphasis is placed on the magnetic coupling structure, which is the most important part of the system. Although this technology has motivated considerable research and development in the past two decades, still there are several theoretical studies such as the level of the operating frequency, operating at high secondary circuit quality factor, coupling efficiency, etc., that need further investigation to fully develop the governing mathematical relationships of this technology

Characterization and Removal of Resins from Mixed Tropical Hardwoods Kraft Pulp

Wood resin of mixed tropical hardwoods (MTH) Kraft pulp was removed and characterized. Characterization of wood resin from different pulping stages was achieved accurately using Pyrolytic Gas Chromatographic-Mass Spectrometry (Py-GC-MS). Two types of resin were recognized: (1) small fraction of unreactive and inaccessible damar resin which was only found to be concentrated in centri-cleaner reject, (2) large fractions of fatty acids, fatty alcohols, and sterols. These can be removed chemically, e.g. by surfactant addition. Results of experiments showed that addition of surfactant enhances removal of extractives and decreases the chemical consumption during bleaching stage

Extraction and purification matairesinol bioactive lignan of arizonica cypress (cupressus arizonica)

Extraction and purification matairesinol bioactive lignan of arizonica cypress (cupressus arizonica) A. Sedaghat1, A. Abdulkhani 2 1. M. Sc, Department of wood and paper science, Faculty of Natural resources, University of Tehran 2. Assistant Professor, Department of wood and paper science, Faculty of Natural resources, University of Tehran Matairesinol lignan (MR) of arizonica cypress was isolated, characterized and purified. Isolated was made using a hexane pretreatment for removing the lipophilic moieties followed by an ethanol-water (9:1 v/v) treatment by soaking the wood flour in the solvents. Also matairesinol, was purified with potassium acetate. Identification of extracts were performed in all stages by means of gas chromatography- mass spectrometry (GC/MS). Results showed that amount of MR lignan in the original ethanol extract, sediment and clear solution after centrifugation was 11.3, 32.59 and 40.44% respectively.... ...... .... .... .... .. ..... .... .... ... .......................................................................................................................... ......... .............................. ..... ...................................................................................................... Keywords: arizonica cypress, gas chromatography- mass spectrometry (GC/MS), wood knot, lignan, matairesinol (MR), extractive

Preparation of cellulose-nylon composite in liquid phase using macro-waves

Dissolution and Cellulose-Nylon composites preparation in liquid phase was studied. BMIMCl ionic liquid was synthesized in the laboratory and was used to perform the dissolution purpose. After the dissolution of the polymers, Cellulose and Cellulose-Nylon composite films were prepared and processed. Then the transparency, water absorption and thickness swelling, water vapor permeability and tensile strength of the composite were determined. Further characterization was performed using SEM and FTIR techniques. Results showed that both polymers were compatibly dissolved in Ionic liquid and homogenously blended which indicates  chemical bonding was established between the polymers. Transparency, water absorption and thickness swelling decreased and water vapor permeability of the composites increased compared to pure cellulosic film. Also, mechanical strength, Young's modulus and strain at break point of the composite were decreased compared to reference cellulosic film

Studing the effect of reducing agents (sodium borhydrade and sodium dithionite) on chemical structures of poplar kraft and bagasse soda alkali lignin by FT-IR spectroscopy

In this study, the chemical changes of functional groups (C=O) and double bond (C=C), induced in the structures of poplar kraft lignin and bagasse soda lignin were investigated. The reducing effect of sodium borohydride and sodium hydrosulfite, followed by the UV irradiation on these two compounds were determined using FT-IR spectroscopy. Results showed that, reduction of the lignin by reducing chemical imparted stability in lignin structure against UV light. The FT-IR spectroscopy showed that, the major light stabilizing phenomenon that is responsible for this stability is the conversion of carbonyl groups (C=O) alcohol group (C-OH) and double bonds (C=C) to single bonds (C-C). Between the two reducing compound, sodium borohydride showed better performance than sodium hydrosulfite

Analysis of Photodegraded Lignin and Lignin Model Compounds by ATR-FTIR Spectroscopy

In this study, optical behavior of methylated and unmethylated Bjorkman lignin from poplar wood and two lignin model compound (phenolic and non phenolic) with β-O-4 linkages was investigated. First, these lignins were precipitated on a cellulosic matrix (Whatman Paper) using different times (0, 5, 10, 15, 20 h) and then matrixcovered surface was analyzed using Attenuated Total Reflectance FTIR technique. The results showed that irradiation altered the chemical structure of all samples. Lignin was the most sensitive component to photodegradation and the intensities of its characteristic bands decreased significantly during the process of irradiation. This was accompanied by formation of new carbonyl groups appearing at 1735 cm_1. Compared with the unmethylated forms, the rate of lignin degradation and carbonyl formation was relatively lower in methylated forms. In other words, methylation of phenolic hydroxyl group reduced the chemical changes induced by irradiation

Chemical structure elucidation of milled wood lignin and cellulytic lignin from Poplar

In this paper, a novel enzymatic method was evaluated for isolation and purification of wood lignin. The chemical structure of enzymatic lignin (Cellulytic lignin) was compared with conventional Bjorkman method (Milled wood lignin). The chemical structure elucidation was performed with FTIR, quantative 13CNMR, basic elemental analysis and Gel Permeation Chromatography (GPC). The results showed that enzymatic lignin preparation has a better chemical structure than MWL. Comparing to conventional isolation methods, application of an enzyme sequence with reduced milling time could lead to a mild extraction with less structural degradation of lignin. Resulting lignin could be more representative for wood lignin than milled wood lignin

Effect of Diluted Acid Pre-Extraction on Soda Pulping of Bagasse

Pre-extraction of hemicelluloses prior to pulping allows co-production of pulp and different hemicellulose-based chemicals in the chemical pulp mills. Due to important impact of hemicelluloses on pulp properties, their pre-extraction would be carried out in controlled conditions to minimize adverse effects on pulp properties. In this study, we focused on the effect of dilute acid pre-extraction on soda pulping and paper properties of bagasse to determine the optimum conditions for hemicelluloses extraction. The pre-extracted with dilute sulfuric acid was performed with 1, 2 and 4% of sulfuric acid concentration (w/v), liquid-to- solid ratio of 5, at 120, and 140 and 160 °C for 5, 10 and 15 minutes. Then, untreated and treated bagasse at selected condition were used to produce soda pulp with 11, 14 and 17% active alkali and then the selected pulps were bleached in ECF sequence. The pre-extraction results showed that dilute acid pre-extraction by 1% H2SO4, at 120 oC for 60 minute provided the best results regarding to extraction yield and residual holocellulose. However, screen yield, bleaching yield, tensile and burst strengths of obtained pulp from extracted bagasse were significantly lower than that obtained from unextracted bagasse, presumably due to considerable extraction of hemicelluloses

Dissolution and regeneration of lignocellulosic materials with ionic liquids BMIMCl and ([BMIM] [MeSO4]) and determination some of mechanical and physical properties

In this study two imidazole-based Ionic liquids, 1- butyl -3 - methyl -1 - Imidazolium chloride (BMIMCl) and 1- butyl -3 - Methyl Imidazolium Methyl sulfate ([BMIM][MeSo4]), were used to dissolve wood flour, cellulose and CMP pulp. The overall evaluation indicates the inability of ([BMIM][MeSo4]) in full dissolution of lignocellulosic materials and sample treatment with this solvent was lead to water soluble degradation products. However, dissolution trials using BMIMCl was able to dissolve Lignocellulosics. Density, clarity, water absorption and thickness swelling of regenerated cellulose films were significantly higher than that of CMP and wood flour, and CMP, higher than wood flour. Also, cellulose film have the lowest water vapor permeability compared to wood flour and CMP. Tensile strength, Young's modulus and strain at breaking point of cellulose film were significantly higher than the CMP and wood flour samples

Chemical Characterization of Ziziphus spina-chrisiti Wood Extractives using Gas Chromatography/Mass Spectroscopy Technique

The polar and non-polar extractives of Ziziphus spina-chrisiti wood were investigated using acetone and ethanol solvents with soxhlet extractor. The extracted portions were further analysed and characterized by GC/MS technique. Results have shown that dinormal-octyl phethalate was the most component of ethanol extracted portion with abundancy of 25.40% and phethalic acid-2-hexyl ester with 2.94% in case of acetone extracted components. Waxes as the most abundance extractives of ziziphus wood were mainly extracted with ethanol and among them dotheriacoanthan was the main componen