Journal articles on the topic 'Resonant transition gate drive'

We propose an experimentally feasible scheme for implementing a two-ion swap gate in the context of the ion-trap system. In this scheme, we drive the ion with one laser beam and we map the states of one ion and the motional mode to each other. The scheme is based on resonant sideband excitation, and thus it may be realized with current ion-trap techniques.

New semiconductor technology is enabling the design of more reliable and high-performance power converters. In particular, wide bandgap (WBG) silicon carbide (SiC) and gallium nitride (GaN) technologies provide faster switching times, higher operating temperature, and higher blocking voltage. Recently, high-voltage GaN devices have opened the design window to new applications with high performance and cost-effective implementation. However, one of the main drawbacks is that these devices require accurate base current control to ensure safe and efficient operation. As a consequence, the base drive circuit becomes more complex and the final efficiency is decreased. This paper presents an improved gate driver circuit for GaN devices based on the use of a constant current regulator (CCR). The proposed circuit achieves constant current regardless of the operating conditions, solving variations with temperature, aging and operating conditions that may degrade the converter performance. Besides, the proposed circuit is reliable and cost-effective, being applicable to a wide range of commercial, industrial and automotive applications. In this paper, its application to a zero-voltage switching resonant inverter for domestic induction heating was performed to prove the feasibility of this concept.

In this study, we implemented a depletion (D)-mode gallium nitride high electron mobility transistor (GaN HEMT, which has the advantage of having no body diode) in a class-E amplifier. Instead of applying a zero voltage switching control, which requires high frequency sampling at a high voltage (>600 V), we developed an innovative control method called the minimum power input control. The output of this minimum power input control can be presented in simple empirical equations allowing the optimal power transfer efficiency for 6.78 MHz resonant wireless power transfer (WPT). In order to reduce the switching loss, a gate drive design for the D-mode GaN HEMT, which is highly influential for the reliability of the resonant WPT, was also produced and described here for circuit designers.

A comparison of radiated noise for Silicon and Silicon Carbide converters is presented. SiC JBS diodes were used in this evaluation to enable fast switching times, whilst minimizing the transistor junction temperature. Radiated electromagnetic-interference measurements showed the highest noise signature for the SiC JFET and lowest for the SiC MOSFET. The negative gate voltage requirement of the SiC MOSFET introduces up to 6 dBµV increase in radiated noise, due to the induced current in the high frequency resonant stray loop in the negative power plane of the gate drive. The SiC JFET and MOSFET have shown overall converter efficiencies of 96% and 95.5% respectively. This efficiency shows only a weak frequency dependence, in contrast to the CoolMOS/SiC JBS diode combination which demonstrated an efficiency drop from 95% to 92.5% when increasing the frequency from 100kHz to 250kHz.

We study a 2-qubit spin model for the possibility of realizing an arbitrary geometric quantum phase gate in terms of a single coherent magnetic pulse with multi-harmonic frequency. Using resonant transition approximation, the time-dependent Hamiltonian of two coupled spins can be solved analytically. The time evolution of the wave function is obtained without adiabatic approximation. The parameters of magnetic pulse, such as the frequency, amplitude, phase of each harmonic part as well as the time duration of the pulse are determined for achieving an arbitrary non-adiabatic geometric phase gate. The requirement of materials for realizing such a gate is analyzed. As a result, the non-adiabatic geometric controlled phase gates and A–A phase are also addressed.

In the inductive power transfer (IPT) system, it is recommended to drive the resonant inverter in zero-voltage switching (ZVS) or zero-current switching (ZCS) operation to reduce switching losses, especially in dynamic applications with variable couplings. This paper proposes an improved autonomous current-fed push-pull parallel-resonant inverter, which not only realizes the ZVS operation by tracking the zero phase angle (ZPA) frequency, but also improves the output power and overall efficiency in a wide range by reducing gate losses and switching losses. The ZPA frequencies characteristic of the parallel-parallel resonant circuit in both bifurcation and bifurcation-free regions is derived and verified by theory and experiments, and the comparative experimental results demonstrate that the improved inverter can significantly increase the output power from 7.68 W to 8.74 W and has an overall efficiency ranging from 63.5% to 72.5% compared with the traditional inverter at a 2 cm coil distance. Furthermore, with a 2-fold input voltage (24 V), the improved inverter can achieve an approximate 4-fold output power of 38.9 W and overall efficiency of 83.6% at a 2 cm coil distance.

Abstract This paper presents the concept and implementation of an electronic system for a switched-capacitor DC-DC converter with high voltage gain. The converter consists of seven switches, five of which being controlled like high-side type. This paper presents a non-typical bootstrap-based gate-driver system so that the converter can run using a single voltage source. The converter requires a special switching pattern to drive seven switches in a steady state and also during the start-up of the converter and the regulation of the output voltage. Therefore, an FPGA-based digital control system is used with various switching algorithms and protection functions implemented. The presented converter is an autonomic device that taps the energy from the main input. Therefore, the electronic system of the converter is equipped with a self-supply system with a wide range of the input voltage. The parameters of the converter such as voltage gain, voltages and power ranges can be scalable for prospective applications with the proposed control system.

A new structure for an exclusive-OR (XOR) gate based on the resonant-tunneling high electron mobility transistor (RTHEMT) is introduced which comprises only an RTHEMT and two FETs. Calculations are done by utilizing a new subcircuit model for simulating the RTHEMT in the SPICE simulator. Details of the design, input, and output values and margins, delay of each transition, maximum operating frequency, static and dynamic power dissipations of the new structure are discussed and calculated and the performance is compared with other XOR gates which confirm that the presented structure has a high performance. Furthermore, to the best of authors' knowledge, it has the least component count in comparison to the existing structures.

This paper proposes a high-efficiency dimmable LED driver for light emitting diodes (LED). The developed LED driver consists of a full-bridge resonant converter and six buck converters. The function of the full-bridge resonant converter is to obtain a smooth dc-link voltage for the buck converters by phase-shift modulation (PSM) while that of the six buck converters is to drive six LED modules, respectively. The gate voltage of the active switch of each buck converter is a combination of high-frequency and low-frequency pulses. The duty ratio of the high-frequency pulse controls the LED voltage and thereby, controls the amplitude of LED current. LEDs are dimmed by low-frequency pulse-width modulation (PWM) to vary the average current flowing through LED. Circuit equations are derived and circuit parameters are designed. High circuit efficiency is ensured by operating the active switches at zero-voltage switching-on to reduce the switching loss. Finally, a prototype circuit was built to verify the accuracy and feasibility of the proposed LED driver.

This paper deals with the implementation of a single phase 15-level Sub-Multilevel Cascaded H-Bridge Inverter (SMCHBI) for variable speed industrial drive applications. It consists of sub-multilevel modules and H-bridge inverter configuration. Sub-multilevel switches synthesize stepped DC link voltage and current from the DC sources. H-bridge inverter switches renovate stepped DC link voltage and current into sinusoidal waveform. Compared with conventional Cascaded Multilevel Inverter (CMLI), the proposed system employs the reduced number of power switches, DC sources and gate driver requirements. The proposed system not only reduces the overall system cost but also reduces the voltage stress across the inverter switches. The proposed system does not required additional resonant soft switching circuits for Zero Voltage Switching (ZVS) of inverter. In the proposed method, variable frequency method is adopted for the speed control of industrial induction motor drives. A prototype model of 15-level SMCHB is developed and the performance of the systems is validated experimentally.

Newborns and hatchlings can perform incredibly sophisticated behaviors, but many animals abstain from sexual activity at the beginning of life. Hormonal changes have long been known to drive both physical and behavioral changes during adolescence, leading to the largely untested assumption that sexuality emerges from organizational changes to neuronal circuitry. We show that the transition to sexuality in male Drosophila is controlled by hormonal changes, but this regulation is functional rather than structural. In very young males, a broadly acting hormone directly inhibits the activity of three courtship-motivating circuit elements, ensuring the complete suppression of sexual motivation and behavior. Blocking or overriding these inhibitory mechanisms evokes immediate and robust sexual behavior from very young and otherwise asexual males. Similarities to mammalian adolescence suggest a general principle in which hormonal changes gate the transition to sexuality not by constructing new circuitry but by permitting activity in otherwise latent motivational circuit elements.

Interfacing solid-state defect electron spins to other quantum systems is an ongoing challenge. The ground-state spin’s weak coupling to its environment not only bestows excellent coherence properties but also limits desired drive fields. The excited-state orbitals of these electrons, however, can exhibit stronger coupling to phononic and electric fields. Here, we demonstrate electrically driven coherent quantum interference in the optical transition of single, basally oriented divacancies in commercially available 4H silicon carbide. By applying microwave frequency electric fields, we coherently drive the divacancy’s excited-state orbitals and induce Landau-Zener-Stückelberg interference fringes in the resonant optical absorption spectrum. In addition, we find remarkably coherent optical and spin subsystems enabled by the basal divacancy’s symmetry. These properties establish divacancies as strong candidates for quantum communication and hybrid system applications, where simultaneous control over optical and spin degrees of freedom is paramount.

We discuss design considerations and construction of a home-built electro-optic phase modulator (EOM) that can be used for locking a laser to an atomic transition. The EOM is designed to operate at a resonant frequency of ≈20 MHz and imposes a phase modulation on a laser beam. The phase-modulated light is sent through a reference cell containing a dilute gas of rubidium atoms. When the laser is scanned over an atomic resonance, the absorption of light through the cell can be detected and mixed down to DC to produce a dispersion shaped “error” signal. The error signal can be used to lock the laser to the atomic resonance. We also describe tests of the basic properties of the resonant circuit. The Q of the circuit is measured to be 10, resulting in 60% efficiency for the first-order sidebands at RF drive powers of 0.7 W. Applications include the spectroscopy of laser-cooled atoms.PACS Nos.: 01.50.Pa, 39.25.+k 32.80.Pj, 42.62.Fi

The conventional cascode structure for driving depletion-mode (D-mode) gallium nitride (GaN) high electron mobility transistors (HEMTs) raises reliability concerns. This is because of the possibility of the gate to source voltage of the GaN HEMT surging to a negative voltage during the turn off transition. The existing solutions for this problem in the literature produce additional drawbacks such as reducing the switching frequency or introducing many additional components. These drawbacks may outweigh the advantages of using a GaN HEMT over its silicon (Si) alternative. This paper proposes two innovative gate drive circuits for D-mode GaN HEMTs—namely the GaN-switching based cascode GaN HEMT and the modified GaN-switching based cascode GaN HEMT. In these schemes, the Si MOSFET in series with the D-mode GaN HEMT is always turned on during regular operation. The GaN HEMT is then switched on and off by using a charge pump based circuit and a conventional gate driver. Since the GaN HEMT is driven independently, the highly negative gate-to-source voltage surge during turn off is avoided, and in addition, high switching frequency operation is made possible. Only two diodes and one capacitor are used in each of the schemes. The application of the proposed circuits is experimentally demonstrated in a high voltage flyback converter, where more than 96% efficiency is obtained for 60 W output load.

Time-resolved luminescence spectra of ZnO epitaxial thin films have been measured by the optical Kerr gate luminescence spectroscopy under resonant excitation of the excitonic state. At moderate excitation density, a luminescence band (P band) which is attributed to an exciton-exciton collision process was observed. With increasing the excitation density, the P band disappears while a new luminescence band (EHP band) due to radiative recombination of electrons with holes in an electron-hole plasma appears. The EHP band has a rise time of ~1 ps, and shifts to lower energy with time and then finally shifts to higher energy. The rise time of the EHP band shows a transition time from a high density excitonic state to an unbound electron-hole system due to the screening of Coulomb interaction. The red shift of the EHP band comes from the reduced band-gap effect, while the blue shift to the EHP band is mainly attributed to recovery of the renormalized band-gap, which occurs with decreasing the carrier density due to the radiative recombination of electrons with holes.

This paper presents a selection of inductor and snubber capacitor in non-isolated synchronous DC-DC switching power converter. The circuit is made to operate in Synchronous Discontinuous Conduction Mode (SDCM)/Forced Continuous Conduction Mode (FCCM) of operation for minimum inductor value, to reduce the size, weight and cost of the converter. The turn off loss of the switch induced by SDCM of operation is minimized by connecting snubber capacitor across the transistor switch. Before the switch is turned ON, snubber capacitor requires certain amount of energy must be stored in the inductor to discharge the capacitor energy [1]. The question is how much capacitor and inductor value is required. A series of MATLAB script are executed to find minimum inductor value for FCCM of operation and to select snubber capacitor for maximum efficiency. Complementary gate signals are used to control the ON and OFF of main and auxiliary switch. SDCM of operation due to complementary control gate signal scheme, minimum turn on loss of the transistor switch and low diode reverse recovery loss are achieved. Thus the Zero Voltage Resonant Transition (ZVRT) of transistor switch is realized, both turn on and turn off loss is minimized and also removes the parasitic ringing in inductor current.

Abstract Persistent superrotation is seen in the atmospheres of other terrestrial bodies (Venus, Titan) but not in that of present Earth, which is distinguished by equatorial easterlies. Nevertheless, superrotation has appeared in numerical simulations of Earth’s atmosphere, from two-layer models to multilevel comprehensive GCMs. Simulations of warm climates that generate enhanced tropical convective variability seem particularly prone to superrotation, which has led to hypotheses that the warmer atmospheres of the early Pliocene and Eocene may have been superrotating, and that the phenomenon may be relevant to future climate projections. This paper considers a positive feedback leading to superrotation based on an equatorial wave resonance that occurs in a westerly background flow. The authors present simulations with an idealized multilevel GCM forced with a zonally varying equatorial heating, which show abrupt transitions to strongly superrotating states. Linear shallow water theory is used to show that these transitions occur as the superrotating jet velocity approaches the phase speed of free equatorial Rossby wave modes, leading to a resonant amplification of the response to eddy heating and its associated equatorward momentum flux. The resonance and transition are most prominent in simulations where the meridional temperature gradient has been reduced, and hysteresis behavior is seen when the gradient is eliminated completely. No evidence is found in these simulations for the midlatitude wave feedback believed to drive abrupt transitions in two-layer models, and there is only a minor role for the axisymmetric feedback based on vertical advection by the Hadley circulation.

Abstract Wide band-gap (WBG) semiconductors offer many potential benefits to designers of power electronic systems. Lower switching losses allow operation at higher switching frequencies, which in principle allows a reduction in passive component values in many converter applications. However, efficient operation at higher switching frequencies requires increased voltage and current transition rates. With conventional packaging and circuit construction, parasitic inductance and capacitance can deteriorate converter performance, reducing efficiency and adding to the electromagnetic interference (EMI) emitted from the system. Outside the commutation cell, fast voltage transitions may lead to unacceptably high levels of conducted and radiated EMI, so approaches involving the local filtering of converter outputs are attractive. To mitigate these effects in conventional modules, switching speeds are often deliberately limited and the potential benefits of using WBG technologies cannot be fully realized. Here we examine the design and realization of Converter-in-Package (CiP) modular blocks for system power levels from 100s W to 100s kW, incorporating individual commutation cells with close-coupled gate drives, input/output filtering and reduced EMI. The concept is illustrated through the realization of a modular, segmented power converter for an integrated drive.

The series resonant DC-DC converter (SRC) can regulate the input voltage in a wide range at a fixed switching frequency. In this work, the bridgeless rectifier, which is utilized intensively in the applications of the power factor correction, has been integrated into the SRC as a voltage step-up cell at the output-side of the SRC. It is shown that the conventional overlapping pulse-width modulation (PWM) of the two metal oxide semiconductor field-effect transistors MOSFETs in this rectification cell limits the input voltage regulation range of the converter due to excessive power losses in abnormal operating conditions. The abnormal operating conditions occur when the instantaneous voltage across the resonant capacitor is larger than the secondary voltage of the isolation transformer. This happens at high values of the DC voltage gain, i.e., low input voltages and high currents, which causes the resonant current to flow in the reverse direction in the same half-cycle through a parasitic path formed by overlapping PWM of the rectifier MOSFETs. The abnormal operation results in additional conduction loss in the converter as the MOSFETs of the bridgeless boost rectifier turn on at high current at the beginning of each half of the switching period. Accordingly, the overall efficiency of the converter significantly deteriorates. This paper proposes the hybrid PWM aiming to improve the efficiency of the SRC with a bridgeless boost rectifier in a wide input voltage regulation range. The converter swaps between the overlapping and the proposed short-pulse PWM schemes to drive the MOSFETs in the bridgeless boost rectifier. The transition between the two PWM schemes is defined according to the boundary condition that relies upon the operating point of the converter power and the input voltage. The proposed hybrid PWM scheme is analyzed and compared to the overlapping PWM at different levels of the input voltage and the load power. A 300 W prototype was studied in the laboratory to show the feasibility of the proposed hybrid PWM scheme with the closed-loop control system to switch between the two PWM schemes.

AbstractThis article examines the implications of the growing presence of the Tablighi Jamaat in Joygram, a Muslim-majority village in rural West Bengal, India, drawing on fieldwork conducted between 2011 and 2013. The analysis of reformist Islam as a moral regeneration movement embedded in dharma and catalysing an alternative modernity contributes to the scholarship on lived experiences of Islam, modernity, and ethics. The Tablighi Jamaat in Joygram gains popularity in a political economic context of moral degradation and marginalization, which inspires engagements with globally resonant modern and anti-modern models of the self enveloped in the practice, discourse, and performance of Islamic reformism. These models mutually interact and conflict with locally particular practices and exclusionary categorizations. On the village level, the drive towards modernity ensues in conflicts over moral personhood and social exchanges. On the societal level, the modern aspirations of Joygrami Tablighis go beyond piety to ‘good culture’ and respected citizenship, and are embedded in anti-modern critiques of the hegemonic categorizations of the secular nation-state by which they are nevertheless confined. It is suggested that reformist Islam should not be misunderstood as pre-modern, anti-secular, or secular, but might better be called ‘post-secular’ because it encompasses those ideologies in vernacularized forms on the basis of a different ideal conception of society. Islamic reformism in Joygram may resonate with moral regeneration and reactionary movements elsewhere. This analysis of the Tablighi Jamaat demonstrates the potential challenges social movements face in the transition to alternative modernities.

High Voltage (HV) switches capable of operating at high speeds and over a wide range of voltages and energies are used in a variety of pulse power applications in material science and plasma physics. Of particular interest is the use of small-scale capacitor discharges to measure the electrical properties of materials as they are heated from solid through liquid to a gas phase. In a capacitive discharge unit (CDU), energy stored in a capacitor is coupled through a switch into a low-impedance transmission line, which typically terminates with a thin sample of material. The energy coupled to the sample is sufficient to cause vaporization. Voltages in such systems range from a few volts to thousands of volts. These vaporized materials are used either as plasma sources for physics experiments, or to propel a thin layer of electrically insulating polymer for high-pressure-impact studies. Several types of switches have been used to drive these systems, including triggered spark gap, dielectric breakdown, and mercury vapor switches. A wide variety of solid-state devices, such as the insulated gate bipolar transistors, are also being utilized for these applications. Inducing a high-pressure shock wave in a dielectric to produce a transition from dielectric to conductor has also been used as an efficient single-shot switch for capacitor discharges. The high-voltage micro-machined switch presented in this document has been designed as a single-use alternative to the more expensive triggered spark gaps and solid-stage devices. The plasma-bridge switch is intended for large-volume, relatively inexpensive systems, and a cost-effective switch for use in destructive testing.

We provide an introduction to the use of ion crystals in a Penning trap for experiments in quantum information. Macroscopic Penning traps allow for the containment of a few to a few million atomic ions whose internal states may be used in quantum information experiments. Ions are laser Doppler cooled, and the mutual Coulomb repulsion of the ions leads to the formation of crystalline arrays. The structure and dimensionality of the resulting ion crystals may be tuned using a combination of control laser beams and external potentials. We discuss the use of two-dimensional $^{9}$Be$^{+}$ ion crystals for experimental tests of quantum control techniques. Our primary qubit is the 124 GHz ground-state electron spin flip transition, which we drive using microwaves. An ion crystal represents a spatial ensemble of qubits, but the effects of inhomogeneities across a typical crystal are small, and as such we treat the ensemble as a single effective spin. We are able to initialize the qubits in a simple state and perform a projective measurement on the system. We demonstrate full control of the qubit Bloch vector, performing arbitrary high-fidelity rotations ($\tau_{\pi}\sim$200 $\mu$s). Randomized Benchmarking demonstrates an error per gate (a Pauli-randomized $\pi/2$ and $\pi$ pulse pair) of $8\pm1\times10^{-4}$. Ramsey interferometry and spin-locking measurements are used to elucidate the limits of qubit coherence in the system, yielding a typical free-induction decay coherence time of $T_{2}\sim$2 ms, and a limiting $T_{1\rho}\sim$688 ms. These experimental specifications make ion crystals in a Penning trap ideal candidates for novel experiments in quantum control. As such, we briefly describe recent efforts aimed at studying the error-suppressing capabilities of dynamical decoupling pulse sequences, demonstrating an ability to extend qubit coherence and suppress phase errors. We conclude with a discussion of future avenues for experimental exploration, including the use of additional nuclear-spin-flip transitions for effective multiqubit protocols, and the potential for Coulomb crystals to form a useful testbed for studies of large-scale entanglement.

AbstractTime-resolved photoluminescence spectra of an ensemble of CuCl quantum dots have been measured by an optical Kerr gate method. The excitation photon energy was tuned to resonant energy for two-photon excitation of biexcitons. We observed that the time profiles of biexciton bands were changed from an exponential fast decay to a pulsed shape. This result indicates a transition from amplified spontaneous emission to superfluorescence. These results will introduce a new field of coherent phenomena originating an ensemble of quantum dots.

Abstract Excellent mechanical properties and the presence of piezoresistivity make single layers of transition metal dichalcogenides (TMDCs) viable candidates for integration in nanoelectromechanical systems (NEMS). We report on the realization of electromechanical resonators based on single-layer MoS2 with both piezoresistive and capacitive transduction schemes. Operating in the ultimate limit of membrane thickness, the resonant frequency of MoS2 resonators is primarily defined by the built-in mechanical tension and is in the very high frequency range. Using electrostatic interaction with a gate electrode, we tune the resonant frequency, allowing for the extraction of resonator parameters such as mass density and built-in strain. Furthermore, we study the origins of nonlinear dynamic response at high driving force. The results shed light on the potential of TMDC-based NEMS for the investigation of nanoscale mechanical effects at the limits of vertical downscaling and applications such as resonators for RF-communications, force and mass sensors.

AbstractFloquet engineering uses coherent time-periodic drives to realize designer band structures on-demand, thus yielding a versatile approach for inducing a wide range of exotic quantum many-body phenomena. Here we show how this approach can be used to induce non-equilibrium correlated states with spontaneously broken symmetry in lightly doped semiconductors. In the presence of a resonant driving field, the system spontaneously develops quantum liquid crystalline order featuring strong anisotropy whose directionality rotates as a function of time. The phase transition occurs in the steady state of the system achieved due to the interplay between the coherent external drive, electron-electron interactions, and dissipative processes arising from the coupling to phonons and the electromagnetic environment. We obtain the phase diagram of the system using numerical calculations that match predictions obtained from a phenomenological treatment and discuss the conditions on the system and the external drive under which spontaneous symmetry breaking occurs. Our results demonstrate that coherent driving can be used to induce non-equilibrium quantum phases of matter with dynamical broken symmetry.

Ambient vibration sources in many prime energy harvesting applications are characterized as having stochastic response with spectra concentrated at low frequencies and steadily reduced power density as frequency increases (colored noise). To overcome challenges in designing linear resonant systems for such inputs, nonlinear restoring potential shaping has become a popular means of extending a harvester's bandwidth downward towards the highest concentration of excitation energy available. Due to recent works which have individually probed by analysis, simulation, or experiment the opportunity for harvester restoring potential shaping near the elastic stability limit (buckling transition) to improve power generation in stochastic environments—in most cases focusing on postbuckled designs and in some cases arriving at conflicting conclusions—we seek to provide a consolidated and insightful investigation for energy harvester performance employing designs in this critical regime. Practical aspects drive the study and encourage evaluation of the role of asymmetries in restoring potential forms. New analytical, numerical, and experimental investigations are conducted and compared to rigorously assess the opportunities and reach well-informed conclusions. Weakly bistable systems are shown to potentially provide minor performance benefits but necessitate a priori knowledge of the excitation environment and careful avoidance of asymmetries. It is found that a system designed as close to the elastic stability limit as possible, without passing the buckling transition, may be the wiser solution to energy harvesting in colored noise environments.

An optimized energy management strategy is designed for a hybrid energy storage system (HESS) to drive the hybrid electric vehicle (HEV) / electric vehicle (EV). Combination of battery and Ultra-Capacitor (UC) forms the HESS for an HEV / EV which will enhance the acceleration performance of the electric motor, reduced battery charge-discharge cycle and improves the driving range. The main aim of the proposed method is to design a control approach for automatic smooth switching between sources of HESS corresponding to the speed of the motor. To achieve the main objective, a new controller is designed with four math functions and programmed separately corresponding to the speed of the motor termed as MFB controller. The fuzzy logic controller is used to obtain the controlled gate pulses for Uni-directional (UDC) and Bi-directional (BDC) converters, those are placed at the battery and UC end. The MFB and Fuzzy logic controllers work together to attain a smooth transition between the battery and UC related to the speed of the electric motor. Finally, the effectiveness of the control strategy is validated with four modes of operation in MATLAB/Simulink.

Abstract Understanding the interaction between light and matter is very relevant for fundamental studies of quantum electrodynamics and for the development of quantum technologies. The quantum Rabi model captures the physics of a single atom interacting with a single photon at all regimes of coupling strength. We report the spectroscopic observation of a resonant transition that breaks a selection rule in the quantum Rabi model, implemented using an LC resonator and an artificial atom, a superconducting qubit. The eigenstates of the system consist of a superposition of bare qubit-resonator states with a relative sign. When the qubit-resonator coupling strength is negligible compared to their own frequencies, the matrix element between excited eigenstates of different sign is very small in presence of a resonator drive, establishing a sign-preserving selection rule. Here, our qubit-resonator system operates in the ultrastrong coupling regime, where the coupling strength is 10% of the resonator frequency, allowing sign-changing transitions to be activated and, therefore, detected. This work shows that sign-changing transitions are an unambiguous, distinctive signature of systems operating in the ultrastrong coupling regime of the quantum Rabi model. These results pave the way to further studies of sign-preserving selection rules in multiqubit and multiphoton models.

AbstractA great deal of research interest is being invested in the fabrication and characterization of nanocrystal structures as charge storage memory devices. In these flash memory devices, it is possible to measure threshold voltage shifts due to charge storage of only a few electrons per nanocrystal at room temperature. Although a variety of methods exist to fabricate nanocrystals and to incorporate them into device layers, control over the critical nanocrystal dimensions, tunnel oxide thickness, and interparticle separation and isolation remains difficult to achieve. This control is vital to produce reliable and consistent devices over large wafer areas. To address these control issues, we have developed a novel two-stage ultra clean reactor in which the Si nanocrystals are generated as single crystal, nonagglomerated, spherical aerosol particles from silane decomposition at 950°C at concentrations exceeding 108 cm−3 at sizes below 10 nm. Using existing aerosol instrumentation, it is possible to control the particle size to approximately 10% on diameter. In the second reactor, particles are passivated with a high quality oxide layer with shell thickness controllable from 0.7 to 2.0 nm. The two-stage aerosol reactor is integrated to a 200 mm wafer deposition chamber such that controlled particle densities can be deposited thermophoretically. With nanocrystal deposits of 1013 cm−2, contamination of transition metals and other elements can be controlled to less than 1010 atoms cm−2.We have fabricated 0.2 μm channel length aerosol nanocrystal floating gate memory devices using conventional MOS ULSI processing on 200 mm wafers. The aerosol nanocrystal memory devices exhibit normal transistor characteristics with drive current 30 μA/μm, subthreshold slope 200 mV/dec, and drain induced barrier lowering 100 mV/V, typical values for thick gate dielectric high substrate doped nonvolatile memory devices. Uniform Fowler-Nordheim tunneling is used to program and erase these memory devices. Despite 5 nm tunnel oxides, threshold voltage shifts > 2 V have been achieved with microsecond program and millisecond erase times at moderate operating voltages. The aerosol devices also exhibit excellent endurance cyclability with no window closure observed after 105 cycles. Furthermore, reasonable disturb times and long nonvolatility are obtained, illustrating the inherent advantage of discrete nanocrystal charge storage. No drain disturb was detected even at drain biases of 4V, indicating that little or no charge conduction occurs in the nanocrystal layer. We have demonstrated promise for aerosol nanocrystal memory devices. However, numerous issues exist for the future of nanocrystal devices. These technology issues and challenges will be discussed as directions for future work.

Apocacidal Tendencies: Three Excerpts from the Heaven's Gate Website 1995 (A term which blends apocalypse with suicide, apocacides could be best described as those groups or individuals who understand salvation from an imagined approaching armageddon to involve, indeed depend upon, the voluntary sacrifice of one's own life on earth.) 1. '95 Statement by An E.T. Presently Incarnate: "... We brought to Earth with us a crew of students whom we had worked with (nurtured) on Earth in previous missions. They were in varying stages of metamorphic transition from membership in the human kingdom to membership in the physical Evolutionary Level Above Human (what your history refers to as the Kingdom of God or Kingdom of Heaven). It seems that we arrived in Earth's atmosphere between Earth's 1940s and early 1990s. We suspect that many of us arrived in staged spacecraft (UFO) crashes and many of our discarded bodies (genderless, not belonging to the human species), were retrieved by human authorities (government and military). Other crews from the Level Above Human preceded our arrival and 'tagged' -- placed a despite 'chip' -- in each of the vehicles (bodies) that we would individually incarnate into, when that instruction would be given. These 'chips' set aside those bodies for us ... In any given civilisation on a fertile planet such as Earth (and Earth has had many periodic/cyclical civilisations), the Level Above Human plants all the new life forms (including humans) for that civilisation in a neutral condition so that they have a chance to choose the direction of their growth. The Level Above Human -- or Next Level -- directly (hands on) relates significantly to the civilisation at its beginning stage, and subsequently (with few exceptions) at approximately 2000-year intervals (48-hour intervals from a Next Level perspective) until that civilisation's final 'Age.' ..." 2. Our Position Against Suicide: " ... We know that it is only while we are in these physical vehicles (bodies) that we can learn the lessons needed to complete our own individual transition, as well as to complete our task of offering the Kingdom of Heaven to this civilisation one last time. We take good care of our vehicles so they can function well for us in this task, and we try to protect them from any harm. We fully desire, expect, and look forward to boarding a spacecraft from the Next Level very soon (in our physical bodies). There is no doubt in our mind that our being 'picked up' is inevitable in the very near future. But what happens between now and then is the big question. We are keenly aware of several possibilities ... The true meaning of 'suicide' is to turn against the Next Level when it is being offered. In these last days, we are focused on ... entering the Kingdom of Heaven ..." 3. Last Chance to Evacuate Earth Before It's Recycled (Sept 29, 1996): "... I'm in a vehicle that is already falling apart on me, and I'm desperate to try to help you have a last chance to go ... I don't mean to make fun of this. I am desperate -- for your sakes. Within the past twenty-four hours I have been clearly informed by my Older Member of how short the remaining time is; how clearly we cannot concentrate on anything except the perspective that says: the end of this civilisation is very close. The end of a civilisation is accompanied by spading under, refurbishing the planet in preparation for another civilisation. And the only ones who can survive that experience have to be those who are taken into the keeping of the Evolutionary Level Above Human ..." Heaven's Gate -- http://www.trancenet.org/heavensgate/index.html Magnificat Meal Movement [Toowoomba, Australia] -- http://homepages.iol.ie/~magnific/ Apocaholic Cocktails: Mixing Visions of the End Armageddon Anonymous: Hidden Faces Plotting the End on Television The 1996 book release X-Files Confidential describes its subject matter as "'social-science fiction' ... fuelled by the realities -- and internal anxieties -- of [our] time: the era of diminished expectations", a television show which "concerns itself with the dark side of technology, competition, politics, ambition, and selfishness", warning against the "risks of abandoning an interior life or one's community" and reinforcing the notion that "our attempts to combat evil are usually an exercise in futility" though that "effort alone is significant". Unlike the participants within the apocaholic communities who intimate that the 'truth is with us', the X-Files, as an entertainment product of the secular industry, proclaims that the 'truth is out there'. This conceptual and narrative framework within the X-Files works on several levels: Frustrates resolution through contrived revelation; Frustrates revelation through contrived resolution; Identifies and resists externally imposed futures; Gives a narrative voice to marginalised hierarchies of genres, values and futures mythology, eg., those involving ufology, genetic mutations and the like; De-emphasises mainstream hierarchies of authority, genres, values and futures mythology; Suggests a regime of hidden truth, embedded within what initially appears as disconnected and unrelated phenomena; Implicates the mainstream future as conspiricist (i.e., the governments which control our futures do not have our interests at heart); Identifies the ritualistic reassurance set by the mainstream discursive strategy (e.g., "apology is policy"); Cultivates its own in-language, or futurespeak, where special terms refer to a future-oriented conspiracy of mammoth proportions. And, finally, it gives meaning to the millennium beyond a mere change in dates. All in all, the X-Files is popular and successful because it explores the possibilities of resolvable and unresolvable endings. It blurs the boundaries between the theological and the secular imaginings of the end. It borrows elements common to contemporary evangelicalism, endtime signs such as the mark of the beast, and gives them a plausible secular narrative. For example, whereas it might be difficult to suspend disbelief for a story that has a charismatic antichrist controlling the world through marking its population with 666, X-Files modernises the setting by creating a mysterious consortium of 12 elders who are in allegiance with some alien plan to initiate a scheduled holocaust. Such an organised drive towards armageddon involves genetic tagging of the populations through smallpox injections, little biochips which switch on and switch-off cancers, transportation of plague through bee stings and heavenly lights that harbour creatures with sinister purposes. In the X-Files, mainstream society is the cult whose future has been pre-organised by its real architects and whose adherents, the general populace, move through society blinded by ideas and doctrines of thought that Mulder sees as lies. His ultimate quest is find the truth, to reveal the future being secretly planned for the world. His quest involves reading the signs of the times in his encounters with the X-Files. Scully, whose initial introduction was to provide a sceptic balance to his quest, in fact provides a scientific rationale for Mulder's seemingly odd flights of fancy. In explaining Mulder's theories away in pseudo-scientific terms, Scully makes the unthinkable seem more plausible, and her character development from sceptic to believer provides the narrative added credibility for long-term viewers. If Scully can be convinced, then there must really be a hidden sinister future embedded beyond the mainstream outlook. Mainstream programmes such as these can in themselves throw wine of the proverbial armageddon fire. Both Star Trek and the X-Files were favourite pastimes for the Heaven's Gate Cult. Star Trek epitomised the ultimate open-ended humanist future, exploration of the unknown, while the X-Files epitomised the nature of this level, a conspiricist and closed future in which the world's only hope lay in the revealing of the sinister unknown before the great destructive end. Needless to say, X-Files-styled sites proliferate the Webscape in late 1999: Apocalypse Soon -- http://www.apocalypsesoon.org/english.html UFOs & Antichrist Millennium Bug Connection New World Order -- http://www.mt.net/~watcher/nwoy2k.html UFOs, Aliens & Antichrist: The Angelic Conspiracy & End Times Deception -- http://www.mt.net/~watcher/ "The Bible says that the b'nai Elohim, angels, sons of God, were ministers of creation, from before the worlds, Job 38:7. Contrary to popular secular theories, the b'nai Elohim are created beings distinct from ELOHIM the God of Israel. God created the b'nai Elohim to reflect His glory, and reflect His word which spoke all things into being. Before a third of the heavenly host rebelled, they were stewards of creation, building civilizations on the terrestrial planets of our solar system designed to glorify the Word of God. The Cydonia "face" is a monument constructed by these Sons of God, revealing their knowledge of the message in the stars. Both the Cydonia face and the Sphinx are cherubim, combining figures in the constellations Virgo and Leo, symbolic representations of the first and second advent of Christ on Earth." Satan's Plan to Escape Judgement -- http://www.mt.net/~watcher/hate.html "Previous pages explained how Satan was created to lead the angelic hierarchy, ruling over physical civilizations of angels on planets, such as the one still in evidence on Mars. After Satan rebelled, the center of his angelic civilization was destroyed "from among the stones of fire", yet the Bible tells us Satan is still waiting for the time of God's judgment. Satan is not in hell, he is still allowed audience before God, where he accuses the faithful (Rev.), and he still roams above and within the earth (Job). Since Satan is the most beautiful and powerful cherub, Prince of the Powers of the Air, intelligence behind UFO phenomena, the authority over all the aerial regions outward from earth..." The Millennium Group -- http://www.millenngroup.com/ Australia's Fair Dinkum Magazine -- http://unforgiven.iweb.net.au/~dinkum/ Eyes on the World -- http://eotw.orac.net.au/articles/index.html Antichrist / False Prophet -- http://members.tripod.com/jonastheprophet1/antipope.html "Antichrist will arise out of the British Monarchy within the context of the European Union/False prophet will arise out of the Vatican-Whore Church/Both will work together to build Satan's end time kingdom in these last and final days." 666 Sketch: The Mark of the Beast -- http://www.greaterthings.com/Essays/666mark.htm Conspiracy Books -- http://parascope.com/parastore/booksconspiracy.htm Corrupt Government, Conspiracy, New World Order, A Future? -- http://www.pushhamburger.com/ Dark Conspiracy -- http://www.blazing-trails.com/DarkConspiracies/welcome.html "Things have gotten really seriously convoluted. To try to follow some of the conspiracies requires a substantial amount of dedication. Any one thread can lead to so many other threads, eventually, maybe they will come together into a complete tapestry that could scare the bejabbers out of you." New World Order Conspiracy -- http://www.ufomind.com/para/conspire/nwo/ Silver Screen Endings: Blockbuster Profits in Apocalypse Gripped in a delirium of apocaholicism, contemporary secular society is exploring the conditions and consequence of endings. Mainstream presentations such as Independence Day, Event Horizon, Armageddon, End of Days, The Matrix and Deep Impact depict the notion of endings in elaborate and extravagant modes. Independence Day is a lesson in Orwellian doublethink -- it begins by destroying the very values it eschews at its closure. The statue of liberty, the White House, and the Empire State Building, all contemporary icons of western democratic and consumerist values, are brutally and spectacularly disintegrated. Yet the very core of the western meta-narrative, the maintenance of independence, which brought about the empowerment of these icons, is upheld throughout the film, leaving a critical viewer with the sense that what we are watching in this film is not the destruction of the world by some alien force -- certainly no other nation is depicted as so grossly devastated nor are any icons of other significantly known cultures destroyed -- but the annihilation of contemporary western icons: essentially, the death of icons. The values are constant, as emoted by the President of the United States towards the fiery conclusion of the movie, but the icons are unstable, susceptible to external disruption, unlike the proverbial humanist spirit. Hence, most audiences reacted gleefully to seeing famous landmarks blasted to smithereens -- this goes hand in hand I suspect with the prevailing social atmosphere cultivating change: do away with the current icons, they are no longer valid nor do they faithfully represent the social world around us, we require new ones to image our emerging spirit. Event Horizon is very different in content and style. It blends conventional theology with science fiction to create an incredible narrative about a starship so fast that it punches a hole through to hell and back. The concern throughout the film as the blood thickens is not with the collective end to society but rather with the very personal and private closure to individual life and the post-death experience. Other films, like Deep Impact and Armageddon, draw on the "worst bits" in the bible, to quote one trailer, and depict disturbing destructive images of the western metropolitan society, with dramatic wrangling over who will survive and how in order to establish a brave new world. What links these varying cinematic depictions of the end? Is it perhaps the imagined triumph of humanist spiritism, usually legitimised through the sacrificial offering of a main character in a film's final showdown? (Bruce Willis dies in Armageddon, Tea Leoni waits with her estranged father for the tidal wave in Deep Impact, and a half-drunk kamikaze pilot in an old biplane destroys the mothership at the close of Independence Day.) Being excessively popular, one needs to ask what role these films play within the collective social narrative of endism: do these films serve to quiet anxieties about the end by visualising human solutions to impossible destructive odds? Or do apocalyptic blockbusters market towards existing endtimes tension, reflecting the growing apocaholic nature of our societies as we near the close of the twentieth century and thereby, in true western capitalist fashion, profit from this cultural dysfunction? Or do films of this nature answer a more base, unacknowledged desire within our societies to see the end and survive? Event Horizon -- http://www.eventhorizonmovie.com/ End of Days -- http://www.end-of-days.com/ The Matrix -- http://www.whatisthematrix.com/ Deep Impact -- http://www.deepimpact.com/ Timeout: Clocking the Endtimes Christian End-Time Expectations -- Millennia Monitor -- http://www.fas.org/2000/endtime1.htm This resource provides links to a wide variety of Christian sources with a primary focus on millennial, apocalyptic, or other End Time expectations. Countdown 2000: Your Guide to the Millennium -- http://www.countdown2000.com/index.htm "As we approach the millennium, the world seems to be getting weirder. Countdown 2000 is packed with the latest news, hype, and hysteria. Where will the blow-out parties be? Will Y2K cause global havoc? How can I get involved in improving the world? Whatever the millennium and year 2000 mean to you, Countdown 2000 can help you learn what you want to know. Countdown 2000 is packed with over 150 pages, and 2500 links." Amazing Prophecy -- http://bibleprophecy.com/ Topics covered: Bible prophecy, rapture, tribulation, millennium, last days, end times, end of time, second coming, covenants, revelation, advent, antichrist, 666, parousia (appearing of Christ), preterist (fulfilled prophecy), eschatology (the study of last things), and many more. 888 Christ Come: Your Bible Prophecy Website -- http://www.888c.com/ Apocalists: The Tribulation Inbox Interesting things happen on discussion lists. Perhaps a more significant example of apocalyptic dissemination, capable of real-time feedback and iteration on endtime signs within every corner of the Web, millions on the bible highway speak of the premillennial tension that characterises contemporary cultural life and thousands more direct these lunges into apocalyptic extrapolation via discussion lists. Nowhere has the apocalyptic urge to image the end, to identify the sign of its approach, been more revitalised than on this electronic frontier: indeed, Apocalypse has an impressive online presence. Today, anyone can receive daily updates sent to their email inbox on the progress or nearness of the great endtimes tribulation, press releases of the latest armageddon publication list, prophecy ezines, the latest incarnation of the mark of the beast 666, new candidates for antichrist identification and revelation reports, to name but a few: Bible Prophecy Discussion List -- http://www.geocities.com/~dawn-/index.html Bible Prophecy-L was created as an open, moderated forum to discuss and share information related to end times Bible prophecy. Some of the topics you may find discussed are: Eschatology; Global Government; Global Religion and the New Age Movement; Rapture; Antichrist; Environmental Changes (earthquakes, tornados, volcanoes, freak storms, flooding etc.); Israel and the Middle East; Signs in the Heavens (UFOs, Comets, etc.); Pestilence (infectious diseases); Wars and Rumors of Wars; Prophecy Conference Updates ... etc. Bible Prophecy Report -- http://philologos.org/bpr Bible Codes News Update -- http://thebiblecodes.com/news/bcnu.htm Tribulation News -- http://www.tribnews.net/mir Conspiracy Journal -- http://www.members.tripod.com/uforeview/welcome.html Citation reference for this article MLA style: Jason Ensor. "Apocacide, Apocaholics and Apocalists: A Selective Webography of Endism." M/C: A Journal of Media and Culture 2.8 (1999). [your date of access] <http://www.uq.edu.au/mc/9912/apocacide.php>. Chicago style: Jason Ensor, "Apocacide, Apocaholics and Apocalists: A Selective Webography of Endism," M/C: A Journal of Media and Culture 2, no. 8 (1999), <http://www.uq.edu.au/mc/9912/apocacide.php> ([your date of access]). APA style: Jason Ensor. (1999) Apocacide, Apocaholics and Apocalists: A Selective Webography of Endism. M/C: A Journal of Media and Culture 2(8). <http://www.uq.edu.au/mc/9912/apocacide.php> ([your date of access]).