A design technique for geometric optimisation of resonant coil sizes in low to mid frequency inductive power transmission systems.

Wireless power transfer (WPT) is a well-established method of energising electrically-powered devices. Among the different available WPT techniques, Resonant Inductive Power Transfer (RIPT) has been adapted for use in a wide range of applications. The primary reason is the relatively higher Power Transfer Efficiency (PTE) that RIPT can provide. RIPT systems operate on the principle of magnetic resonance coupling between a Transmitter (Tx) and a Receiver (Rx) coil. Maximising the PTE is a key driver for improving the performance of RIPT systems. In a RIPT link the PTE is influenced by three factors: (i) inductive linkage between the Tx and Rx, (ii) terminating circuitry of Tx and Rx sides and (iii) the Tx/Rx coil's geometrical size. In considering these impacting factors, different techniques to improve PTE have been extensively presented in the literature and are comprehensively reviewed in this thesis. The research work undertaken focuses on the geometrical optimisation of Tx/Rx coils to help maximise PTE in RIPT systems for operation over low- and mid-frequency bands (i.e. between few kHz to several MHz). Conventional methods for maximising PTE require defining various design parameters (i.e. figure-of-merits), which assist in finding the optimum Air-Cored Coil (ACC) geometry. However, traditional techniques for working with Figure-of-Merit (FoM) parameters are very time-consuming and process-demanding. In this thesis, the number of required FoMs have been reduced to one and incorporated into a process that will accelerate production of the optimum geometry design. A unique FoM parameter (i.e. Pscf) is developed by consolidating the PTE's impacting factors. Considering the RIPT application and its physical size constraints, a proper selection method for identifying the numerical value of Pscf is investigated. A novel iterative algorithm has been developed to assist in selection of the most favourable Pscf value, which provides the optimum ACC geometry. Theoretical design examples of two RIPT systems - operating at 10 kHz (low-frequency band) and 300 kHz (mid-frequency band) - are used to investigate the functionality of the ACC design approach, for which successful results are achieved. The novel iterative algorithm is also experimentally validated by developing four prototyped Tx/Rx ACC pairs, with real-world applications, which operate over low- and mid-frequency bands: 1:06 MHz, 100 kHz, 50 kHz, 15 kHz. For the designed ACC geometries, maximum PTEs of 85:63% at 1:06 MHz, 83:10% at 100 kHz, 72:85% at 50 kHz and 34:57% at 15 kHz are practically measured in bench top tests. The measured PTE values are in close correlation (within 14%) with the calculated PTEs at these frequency ranges, and thus validate the novel ACC design procedure. The RIPT system's maximum achievable PTE can be further increased by adding ferrite cores to the Tx/Rx ACC pair. In this thesis, an advanced iterative algorithm is also presented to support the design of geometrically optimised coil pairs employing ferrite cores. The advanced iterative algorithm is an extension of the initial work on optimising ACC geometries. Optimum Ferrite-Cored Coil (FCC) geometries, produced using the advanced iterative algorithm, for RIPT systems operating at 10 kHz and 300 kHz have been investigated. In comparing the FCC and ACC geometries designed for these frequencies, it is demonstrated that RIPT systems with ferrite cores reduce the ACC's geometrical size and additionally improve PTE. To validate the performance of the advanced FCC design algorithm over low- and mid-frequency bands, two RIPT systems are physically constructed for operation at 15 kHz (low-frequency) and 50 kHz (mid-frequency). For the prototyped RIPT systems, maximum PTEs of 45:16% at 50 kHz and 50:74% at 15 kHz are practically measured. The calculated and physically measured PTE values are within 2% difference; hence validating the advanced FCC design process

A design technique for optimizing resonant coils and the energy transfer of inductive links.

Power transfer efficiency (PTE) is a key performance parameter in development work on resonant inductive power transfer (IPT) systems. Geometrically optimizing the transmitter (Tx) and receiver (Rx) coil pair is a way of improving the IPT system's efficiency. In this article, a new figure-of-merit (FoM) is proposed to find an optimum coil geometry which maximizes the PTE. The employed FoM parameter, called the 'strong coupling factor' (Pscf), is defined such that its value indicates how strongly the Tx and Rx coils are linked together. Considering the IPT application and its physical size constraints, a proper selection method for identifying the numerical value of Pscf is essential for optimal coil geometry design. This article presents an iterative algorithm to assist in the selection of the most favorable Pscf value which provides maximized PTE for the designed optimum coil geometry. Design examples of two nominal IPT systems at frequencies of 415 and 0.1 MHz are used to investigate the design algorithm. Theoretical calculations show the optimum geometry designed for the IPT system operating at 415 MHz, with coupling coefficient (K) of 0.2, can achieve maximum PTE of 85.70%. Measurements presented from a practical Tx/Rx coil pair in the IPT link operating at 0.1 MHz, with K=0.05, show a PTE of 83.10% against a calculated PTE of 84.11% validating the design process.This article is an expanded version from the IEEE Wireless Power Week, London, U.K., June 17–20, 2019

Attitude control of VTOL-UAVs.

This paper presents a novel control approach to obtain asymptotic attitude stability of a quadrotor as a representative of Planar Vertical Take Off and Landing (PVTOL) Unmanned Aerial Vehicles (UAVs). The considered quadrotor is a symmetric VTOL-UAV with four rigid mono-directional propellers, which has been modeled based on quaternion representation with taking Coriolis and gyroscopic torques into account. In the proposed approach, two nearly equivalent control laws (model independent as well as model dependent) have been used to obtain exponential stability of attitude angles and asymptotic stability of attitude angular velocity of the quadrotor UAV. The proposed approach also presents how the attitude parameters i.e. attitude angles and attitude angular velocity can be quickly regulated to their desired values as required

The effects of hesperetin on apoptosis induction andinhibition of cell proliferation in the prostate cancer PC3 cells

ntroduction: Prostate cancer is the second leading cause of cancer-related deaths and the mostcommon cancer diagnosed in men in the United States and Europe. Hesperetin, a member of thef lavonoids with antioxidant property, is found in fruits such as oranges and red fruits. This study was undertaken to evaluate the effects of hesperetin on apoptosis induction and inhibition of cell proliferation in the prostate cancer PC3 cells.Methods: PC3 cell line was cultured in standard condition. The cells were exposed to differentconcentrations of hesperetin (0-1000 μM) for 48 hours. Cell viability was measured by MTT assay.Apoptosis induction was assessed by Annexin V-FITC by flow cytometry analysis.Results: The PC3 cells exposed to hesperetin (0-1000 μM) exhibited an IC (inhibitoryconcentration of 50) about 450 μM. At different concentrations of hesperetin (400, 450 and 500µm), the apoptosis increased slightly (not significant) in treated PC3 cells compared to the controlgroup (5.4, 7.8 and 9.1 respectively vs. 4.2).Conclusion: These results clearly show that hesperetin can lead to inhibition of PC3 cellsproliferation.&nbsp

Improving the design approach to developing through-metal communications for use in subsea pipeline robots.

Vital inspection and repair operations on subsea pipelines usually involve pipe-bore robots, which must be controlled and monitored from outside the pipe. In many situations cables cannot be connected to the in-pipe robot and duplex wireless communication through pipe-wall is the only solution. Wireless power transmission (WPT) through pipe-wall has been considered to facilitate the required duplex communication. In WPT through subsea pipe-walls the conductive media (i.e.: stainless steel and seawater.) will significantly reduce the power transfer efficiency (PTE) of the system. This paper proposes a coil geometry optimisation methodology to boost PTE of these wireless communication systems. The proposed technique, in addition to increasing the PTE improves the overall system’s signal to noise ratio by reducing the coil antenna’s internal resistance

Maximising inductive power transmission using a novel analytical coil design approach.

Maximising power transfer efficiency (PTE) in resonant inductive power transfer (IPT) systems requires strong coupling between transmitter and receiver coils. In applications where system constraints yield a weak inductive link (e.g. significant distance between coils) or there is a requirement for a specific power level, then geometrically optimising the coils can enhance inductive linkage. To achieve this, a novel coil design method has been presented which provides maximum efficiency for both strongly- and loosely-coupled inductive links. A parameter (i.e. "Strong Coupling Factor") has been introduced to assist the design procedure. Discussing results from a practical 1.06 MHz inductive link - developed using the proposed design method - shows that, with proper selection of strong coupling factor (e.g. C=220), the designed coil geometry can provide maximum PTE of 86%. This is in close correlation (F ≈ 3%) with theoretical analysis using MATLAB

Adiponectin inhibits oxidized low density lipoprotein-induced increase in matrix metalloproteinase 9 expression in vascular smooth muscle cells

BACKGROUND: High expression of matrix metalloproteinase 9 (MMP9) during vascular injury and inflammation plays an important role in atherosclerotic plaque formation and rupture. In the process of atherosclerosis, oxidized low-density lipoprotein (oxLDL) upregulates MMP9 in human aortic vascular smooth muscle cells (HA/VSMCs). Adiponectin is an adipose tissue-derived hormone that has been shown to exert anti-atherogenic and anti-inflammatory effects. The aim of this study was to investigate the effect of adiponectin on MMP9 expression under pathogenic condition created by oxLDL in HA/VSMCs. METHODS: In this experimental study, HA/VSMC were stimulated with oxLDL alone and in the presence of adiponectin for 24 and 48 h. The expression of MMP9 gene was determined by real-time polymerase chain reaction method. The protein level of this gene was investigated by western blotting technique. RESULTS: An oxLDL increased MMP9 expression 2.16 +/- 0.24- and 3.32 +/- 0.25-fold after 24 and 48 h, respectively and adiponectin decreased oxLDL-induced MMP9 expression in a time-dependent manner. CONCLUSION: These results show that adiponectin changes extracellular matrix by reducing MMP9 mRNA and protein, therefore, may stabilize lesions and reduce atheroma rupture

Potential role of a nutraceutical spice (<em>Allium hirtifolium</em>) in reduction of atherosclerotic plaques

Introduction: Spices are now considered as agents that not only can prevent but may even treat chronic diseases. This study was aimed to investigate the effects of Allium hirtifolium as a hypolipidemic and anti-atherosclerotic substance in hypercholesterolemic rabbits. Methods: Twenty four adult New Zealand male rabbits were divided randomly into 3 groups of 8 animals each and treated for 60 days as follows. Normal group received basal feed, while the two intervention groups were fed with hypercholesterolemic diet (1 cholesterol) and hypercholesterolemic diet plus A. hirtifolium extract, respectively. At the start and the end of the experiment, fasting blood was taken from all animals. Serum concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), apolipoproteins A and B, serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), high-sensitivity C-reactive protein (hs-CRP), glucose and insulin were measured at the end of supplementation period in all studied groups. Atherosclerotic plaque thickness of aorta to media was also determined in all groups. Results: Rabbits fed only with high cholesterol diet showed increased atherosclerotic plaque thickness to media compared to the control group, while the group fed with hypercholesterolemia diet plus A. hirtifolium extract significantly decreased atherosclerotic plaque thickness to media, TC, TG, LDL-C, and significantly increased HDL-C compared to hypercholesterolemic diet group. Supplementation with A. hirtifolium extract did not cause any significant alteration in apolipoproteins, SGOT, SGPT, hs-CRP, glucose and insulin compared to the hypercholesterolemic diet group (p&gt;0.05). Conclusion: Ethanolic extract of A. hirtifolium ameliorates fatty lesions in aorta and may reduce risk factors of cardiovascular diseases.</p

Potential role of a nutraceutical spice (Allium hirtifolium) in reduction of atherosclerotic plaques

Introduction: Spices are now considered as agents that not only can prevent but may even treat chronic diseases. This study was aimed to investigate the effects of Allium hirtifolium as a hypolipidemic and anti-atherosclerotic substance in hypercholesterolemic rabbits. Methods: Twenty four adult New Zealand male rabbits were divided randomly into 3 groups of 8 animals each and treated for 60 days as follows. Normal group received basal feed, while the two intervention groups were fed with hypercholesterolemic diet (1% cholesterol) and hypercholesterolemic diet plus A. hirtifolium extract, respectively. At the start and the end of the experiment, fasting blood was taken from all animals. Serum concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), apolipoproteins A and B, serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), high-sensitivity C-reactive protein (hs-CRP), glucose and insulin were measured at the end of supplementation period in all studied groups. Atherosclerotic plaque thickness of aorta to media was also determined in all groups. Results: Rabbits fed only with high cholesterol diet showed increased atherosclerotic plaque thickness to media compared to the control group, while the group fed with hypercholesterolemia diet plus A. hirtifolium extract significantly decreased atherosclerotic plaque thickness to media, TC, TG, LDL-C, and significantly increased HDL-C compared to hypercholesterolemic diet group. Supplementation with A. hirtifolium extract did not cause any significant alteration in apolipoproteins, SGOT, SGPT, hs-CRP, glucose and insulin compared to the hypercholesterolemic diet group (p>0.05). Conclusion: Ethanolic extract of A. hirtifolium ameliorates fatty lesions in aorta and may reduce risk factors of cardiovascular disease

Optimal coil design for maximum power transfer efficiency in resonantly coupled systems.

Maintaining maximum power transfer efficiency (PTE) is one of the main challenges in resonant inductive power transfer (IPT) systems. Maximum PTE can be achieved if the coupling between transmitter and receiver coils is strong. One way of achieving this is to geometrically optimise a coil by employing small ohmic resistance combined with high self-inductance. In this paper a design method for an optimum coil geometry which offers maximum PTE has been introduced. The proposed technique, in addition to minimising the system's physical size, provides high level of PTE for both strongly- and loosely-coupled links. A design example for a typical IPT system is presented that shows, with a proper selection of strong coupling factor (e.g.: C = 220.), the designed coil geometry can provide maximum PTE of 95.4% for coupling coefficient K = 1. Also, for a loose inductive link with K = 0.215, maximum calculated and measured PTE values are 89% and 86%, respectively