High Frequency Pulse Research Articles

Monitoring corrosion in oil pipelines using non-destructive test

The age of the pipelines is a factor in increasing the potential risk to corrosion in pipelines hence reduces the safety of pipelines, and gets pipelines more likely to explosion or breakage. Thus, that will threaten the safety of individuals and the environment. According to corrosion is the main reason that threatens the pipeline. The danger is not limited to residents, but it could be worrisome if any the leak happened near the water sources. Thus, it will be difficult to address quickly, and requires significant costs could reach billions of dollars. Therefore, it is important to study the reasons that could be caused the pipeline explosion to avoided any effects could be happened, for example, in this paper we will focused on corrosion that happened in oil pipe depending on ultrasonic test methods (UT) to test sample of pipeline. Ultrasonic test is a test which is done by transfer a high frequency pulse through test object and receives a reflected echoes by analyzing the reflected waves which will help us to determine the thickness and other material properties.

Echolocation while drinking: Pulse-timing strategies by high- and low-frequency FM bats.

During nightly foraging activity, echolocating bats drink by flying low over the water surface and dipping the lower jaw while avoiding further bodily contact with the water. This task poses different sensorimotor challenges than flying in the open to forage for insects. Of interest is how bats adjust the timing of their echolocation pulses to accommodate the surrounding scene, from the progressively nearer water surface itself to objects at longer distances. Drinking behavior has been described in only a few of the roughly 1,000 echolocating bat species, and in none of the 110 species in the Indian subcontinent. Here, we describe how bats emitting frequency-modulated (FM) echolocation pulses behaved while drinking from a swimming pool in urban northeast India. At least two different bat species were present, using 1st-harmonic frequencies sweeping down to about 35 Hz ("low frequency") and down to about 50 kHz ("high frequency"), separable at a 40 kHz boundary. Over entire drinking maneuvers, intervals between broadcast pulses accommodate both the proximate task of registering the water surface while drinking and registering echoes from the farther reaches of the scene. During approach to the water, both low and high frequency bats emit longer, more stable interpulse intervals that matched the time interval covering echo arrival-times out to the frequency-dependent maximum operating range. High frequency bats use shorter interpulse intervals than low frequency bats, consistent with the shorter operating range at higher frequencies. Bats then accelerate their pulse rate to guide the dive down to drinking, with low frequency bats continuing to decrease pulse intervals and high frequency bats maintaining a more steady interval during the drinking buzz. The circumstance that both groups were engaged in the same task made this a natural experiment on the behavior during approach.

Optical characteristics and parameters of gas discharge plasma on a mixture of cadmium diodide vapor with helium and small addition of nitrogen

Наведено результати дослідження спектральних, інтегральних і ресурсних характеристик випромінювання газорозрядної плазми атмосферного тиску на багатокомпонентних сумішах дийодиду кадмію з гелієм і малої добавки молекулярного азоту. Створення газорозрядної плазми і збудження компонент робочої суміші здійснювалося імпульсно-періодичним (частота проходження імпульсів 18–20 кГц, тривалість імпульсів 150 нс) бар’єрним розрядом. Виявлено випромінювання у видимій області спектру ексиплексних молекул монойодиду кадмію, атомів кадмію. Встановлено закономірності в змінах оптичних характеристик плазми в залежності від частоти проходження імпульсів накачки, компонентного і кількісного складу сумішей. Представлено обговорення результатів досліджень. Дані досліджень представляють інтерес для створення ексиплексних газорозрядних джерел видимого випромінювання з максимумом випромінювання на довжині хвилі λ=650 нм.

Simplified Non-Thermal Tissue Ablation With a Single Insertion Device Enabled by Bipolar High-Frequency Pulses.

To demonstrate the feasibility of a single electrode and grounding pad approach for delivering high frequency irreversible electroporation treatments (H-FIRE) in in-vivo hepatic tissue. Ablations were created in porcine liver under surgical anesthesia by adminstereing high frequency bursts of 0.5-5.0μs pulses with amplitudes between 1.1-1.7 kV in the absence of cardiac synchronization or intraoperative paralytics. Finite element simulations were used to determine the electric field strength associated with the ablation margins (ELethal) and predict the ablations feasible with next generation electronics. All animals survived the procedures for the protocol duration without adverse events. ELethal of 2550, 1650, and 875V/cm were found for treatments consisting of 100x bursts containing 0.5μs pulses and 25, 50, and 75μs of energized-time per burst, respectively. Treatments with 1μs pulses consisting of 100 bursts with 100μs energized-time per burst resulted in ELethal of 650V/cm. A single electrode and grounding pad approach was successfully used to create ablations in hepatic tissue. This technique has the potential to reduce challenges associated with placing multiple electrodes in anatomically challenging environments. H-FIRE is an in situ tumor ablation approach in which electrodes are placed within or around a targeted region to deliver high voltage electrical pulses. Electric fields generated around the electrodes induce irrecoverable cell membrane damage leading to predictable cell death in the relative absence of thermal damage. The sparing of architectural integrity means H-FIRE offers potential advantages compared to thermal ablation modalities for ablating tumors near critical structures.

The Effect of Accumulated Charges and Fluid Dynamics on the Helium Plasma Jet Array Behavior

This paper investigated the effect of accumulated charges and fluid dynamics on the helium plasma jet array behavior. The plasma jet array was composed of three individual plasma jets in a parallel arrangement. The dynamic evolution and the hydrodynamic interaction of plasma jets were observed under for adjacent jet-to-jet distances, pulse frequencies, and pulsewidths. The results showed that variation of the above parameters exerted an influence on the distribution of accumulated charges and gas flow, and thus controlled the outside and middle jet lengths. With a small pulse frequency and pulsewidth, the higher air fraction in the middle jet trajectory prevented its propagation and resulted in a shorter middle jet length. The increase of the pulse frequency or pulsewidth induced higher charge accumulation, and thus the deflection of the outside jets was more significant. At the same time, the gas flow channel showed a similar divergence and changed the air participation in the jet array, which explained a shorter middle jet length under a higher pulse frequency or pulsewidth. The results obtained in this work helped to understand the plasma jet interaction mechanism in the plasma jet array and to develop a uniform large-area discharge plasma.

Improvement of microstructures and properties of copper-aluminium oxide coating by pulse jet electrodeposition

Cu-Al2O3 nanocomposite coatings were jet electrodeposited using a direct current and pulse current to enhance the quality of the deposition and its mechanical properties. The composite coating prepared with a pulse current exhibited a smooth surface morphology, dense microstructure and good mechanical properties compared with those of the coatings obtained under direct current conditions. The effect of the pulse parameters, including the current density and pulse frequency, on the morphologies, microstructures, grain growth, and properties of the coatings was also examined. The results show that a high pulse frequency and appropriate current density improved the quality of the deposition and its mechanical properties. A dense nanocomposite copper-alumina deposited coating with an average refined grain size of 26 nm was fabricated with a pulse current density of 400 A dm−2 and a pulse frequency of 5000 Hz. The microhardness and tensile strength of the nanocomposite coating attained maximum values of 2.37 GPa and 692 MPa, respectively, when the optimum deposition conditions were used.

Implementation architecture of signal processing in pulse Doppler radar system based on FPGA

A kind of high speed and parallel hardware architecture is proposed and designed for digital signal processing of high frequency Pulse Doppler radar here. The platform is based on one XC7K410T FPGA, two XC7K325T FPGAs, one TMS320C6678 DSP, and four sets of MT41J256M8 DDR3. The details of implementation including pulse compression, moving target detection and constant-false-alarm rate are described. The simulation results and resource consumption are presented to demonstrate the advantages of the proposed FPGA implementation architecture.

P3522Vagus nerve stimulation for chronic heart failure: differences in therapy delivery and clinical efficacy in ANTHEM-HF, INOVATE-HF, and NECTAR-HF

Abstract Background Vagus Nerve Stimulation (VNS) is meant to deliver Autonomic Regulation Therapy (ART) to neurological targets with sufficient neuromodulation (NM) to ameliorate chronic heart failure (CHF). VNS delivery consists of its intensity (a combination of pulse amplitude, pulse frequency, and pulse duration), polarity, duty cycle (DC; stimulation “on” time and “off” time), and mode (continuous, or intermittent and periodic). In the ANTHEM-HF Pilot Study patients with CHF and reduced ejection fraction (HFrEF), VNS intensity was up-titrated until a change in heart rate (HR) dynamics was objectively confirmed. This did not require any change in GDMT and was associated with significant improvements in LVEF, 6-minute walk distance (6MWD), Minnesota Living with HF (MLWHF) score, and HR variability. Methods Qualitative and quantitative analyses used data from peer-reviewed publications and other sources in the public domain to compare VNS delivery in ANTHEM-HF, INOVATE-HF, and NECTAR-HF. Results (Table): Up-titration of VNS intensity was attempted in all 3 studies. In contrast to ANTHEM-HF, INOVATE-HF aimed only at peripheral neural targets. VNS intensity was delivered at a lower pulse frequency, and had a variable DC as a consequence of R-wave synchronization and only intermittent, periodic stimulation. In NECTAR-HF VNS intensity was delivered at a higher pulse frequency, and this was associated with intolerable adverse off-target effects which restricted VNS up-titration. Significant improvements in EF, 6MWD, MLWHF, and SDNN occurred in ANTHEM-HF relative to the other studies. ANTHEM-HF (n=60) INOVATE-HF (n=436) NECTAR-HF (n=63) Neural Target Central/Peripheral Peripheral Central/Peripheral Delivery Site Left or right CVN Right CVN Right CVN Delivery Intensity: Amplitude (milliamperes) 2.0±0.6 3.9±1.0 1.4±0.8 Frequency (Hertz) 10 1–2 20 Duration (microseconds) 250 500 300 Electrode Polarity (Cathode) Caudal Cephalad Caudal Duty Cycle 23% 25% 17% On Time/Off Time (seconds) 18/62 Variable 10/50 Mode of Delivery Cyclic/Continuous Intermittent/Periodic Cyclic/Continuous Clinical Efficacy at 6 Months: EF 32.4±7.2 to 37.2±10.4 Not available 30.5±6.0 to 32.7±6.4 6MWD 287±66 to 346±78 317±109 to 347±123 Not available MLWHFS 40±14 to 21±10 Not available 44.2±22.2 to 35.8±20.8 SDNN 94±26 to 111±50 Not available 146±48 to 130±52 Values reported as mean ± standard deviation; CVN = Cervical vagus nerve. *p<0.05 versus NECTAR-HF; **p<0.05 versus INOVATE-HF; ***p<0.025 versus NECTAR-HF; ****p<0.001 versus NECTAR-HF (Analysis using two-sample t-test of the means). Conclusion VNS differed in ANTHEM-HF when compared to INOVATE-HF and NECTAR-HF. The neural targets, pulse frequencies for titration, and the DC for NM were different. VNS in ANTHEM-HF was clinically efficacious. The ongoing ANTHEM-HFrEF Pivotal Study uses a similar paradigm. Acknowledgement/Funding LivaNova PLC

Translingual Neurostimulation for the Treatment of Chronic Symptoms Due to Mild-to-Moderate Traumatic Brain Injury

ObjectiveTo compare the efficacy of high- and low-frequency noninvasive translingual neurostimulation (TLNS) plus targeted physical therapy (PT) for treating chronic balance and gait deficits due to mild-to-moderate traumatic brain injury (mmTBI). DesignParticipants were randomized 1:1 in a 26-week double-blind phase 1/2 study (NCT02158494) with 3 consecutive treatment stages: in-clinic, at-home, and no treatment. Arms were high-frequency pulse (HFP) and low-frequency pulse (LFP) TLNS. SettingTLNS plus PT training was initiated in-clinic and then continued at home. ParticipantsParticipants (N=44; 18-65y) from across the United States were randomized into the HFP and LFP (each plus PT) arms. Forty-three participants (28 women, 15 men) completed at least 1 stage of the study. Enrollment requirements included an mmTBI ≥1 year prior to screening, balance disorder due to mmTBI, a plateau in recovery with current PT, and a Sensory Organization Test (SOT) score ≥16 points below normal. InterventionsParticipants received TLNS (HFP or LFP) plus PT for a total of 14 weeks (2 in-clinic and 12 at home), twice daily, followed by 12 weeks without treatment. Main Outcome MeasuresThe primary endpoint was change in SOT composite score from baseline to week 14. Secondary variables (eg, Dynamic Gait Index [DGI], 6-minute walk test [6MWT]) were also collected. ResultsBoth arms had a significant (P<.0001) improvement in SOT scores from baseline at weeks 2, 5, 14 (primary endpoint), and 26. DGI scores had significant improvement (P<.001-.01) from baseline at the same test points; 6MWT evaluations after 2 weeks were significant. The SOT, DGI, and 6MWT scores did not significantly differ between arms at any test point. There were no treatment-related serious adverse events. ConclusionsBoth the HFP+PT and LFP+PT groups had significantly improved balance scores, and outcomes were sustained for 12 weeks after discontinuing TLNS treatment. Results between arms did not significantly differ from each other. Whether the 2 dosages are equally effective or whether improvements are because of provision of PT cannot be conclusively established at this time.

Long-Term Treatment of Balance Deficits After Mild-to-Moderate TBI With the Portable Neuromodulation Stimulator

To determine whether the Portable Neuromodulation Stimulator (PoNS) plus targeted physical therapy (PT; PoNS treatment) at a high-frequency pulse (HFP) is more efficacious than a low-frequency pulse (LFP) in participants with chronic symptoms due to mild-to-moderate traumatic brain injury (mmTBI).

The Portable Neuromodulation Stimulator for Chronic Symptoms Due to Mild-to-Moderate Traumatic Brain Injury

To determine whether training using the Portable Neuromodulation Stimulator (PoNS) at a high-frequency pulse (HFP) is more efficacious than training using a low-, but perceivable, frequency pulse (LFP) combined with targeted physical therapy (PT) in participants with balance deficits due to mild-to-moderate traumatic brain injury (mmTBI).

Power Pulsing To Maximize Vibrational Excitation Efficiency in N2 Microwave Plasma: A Combined Experimental and Computational Study

Plasma is gaining increasing interest for N2 fixation, being a flexible, electricity-driven alternative for the current conventional fossil fuel-based N2 fixation processes. As the vibrational-induced dissociation of N2 is found to be an energy-efficient pathway to acquire atomic N for the fixation processes, plasmas that are in vibrational nonequilibrium seem promising for this application. However, an important challenge in using nonequilibrium plasmas lies in preventing vibrational-translational (VT) relaxation processes, in which vibrational energy crucial for N2 dissociation is lost to gas heating. We present here both experimental and modeling results for the vibrational and gas temperature in a microsecond-pulsed microwave (MW) N2 plasma, showing how power pulsing can suppress this unfavorable VT relaxation and achieve a maximal vibrational nonequilibrium. By means of our kinetic model, we demonstrate that pulsed plasmas take advantage of the long time scale on which VT processes occur, yielding a very pronounced nonequilibrium over the whole N2 vibrational ladder. Additionally, the effect of pulse parameters like the pulse frequency and pulse width are investigated, demonstrating that the advantage of pulsing to inhibit VT relaxation diminishes for high pulse frequencies (around 7000 kHz) and long power pulses (above 400 μs). Nevertheless, all regimes studied here demonstrate a clear vibrational nonequilibrium while only requiring a limited power-on time, and thus, we may conclude that a pulsed plasma seems very interesting for energy-efficient vibrational excitation.

Flow characteristics of the molten pool in pulsed laser welding of thin sheet with filler wire

A 3D transient model has been developed to analysis the molten pool flow characteristic in pulsed laser welding thin sheet with filler wire. The free surface is tracked by VOF method, and the filler metal is simplified as droplets. The flow characteristics in welding of Hastelloy C-276 sheets with 0.5 mm in thickness are analyzed with this model. The calculated weld appearance fits well with the experimental one. Before the droplet contacts with the molten pool, the liquid metal driven by surface tension flows towards the center and downward at the upper surface. The max velocity at the center is about 0.97 m/s. At the trailing portion of lower surface, two eddies with similar spin direction are generated due to the outward surface flow and the downward flow. The filler metal has significant influence on the convection pattern in the molten pool, and results in the disappearance of flow characteristics dominated by surface tension. The filler metal flows downward and outward rapidly after the droplet contact with molten pool. The maximum velocity is about 1.74 m/s and appears at the location where the droplet enters into the molten pool. The droplet has an impact effect on the molten pool and the convection pattern is changed. The molten pool shows oscillation characteristic due to the combined effect of droplet impact and surface tension. The volume of the molten pool dose not decrease right after the laser pulse ends, the lower part of the molten pool expands for about 3–4 milliseconds. And this phenomenon is related to the pulse effect of the laser beam, the flow pattern of the molten pool and the thermal properties of the material. Due to high pulse frequency of the laser beam and low thermal conductivity of the material, the molten pool always exists during welding process.

Impedance Informed, High Frequency Pulse Charging As Method to Enable Stable Low Temperature Li-Ion Battery Operation

Low temperature cycling of Li-ion batteries can have two major complications: incomplete intercalation in the anode and lithium metal deposition.1-2 These complications lead to a loss in capacity and cell instability caused by lithium deposits inside the cell. Instability within the cell can cause the battery to begin an exothermic reaction and go into thermal runaway, resulting in a potentially hazardous reaction. Herein we use a pulse charging technique to overcome the limitations associated with low temperature cycling. Commercial 18650 cells were cycled 50 times at 25°C (ambient), 0°C, and at 0°C using a pulse charging technique. The parameters of pulse charge were determined using a single point impedance technique.3 Electrochemical impedance spectroscopy (EIS) was acquired at 10% increments of state of charge (SOC). The frequency least dependent on state of charge indicates a time constant of ion movement where the solid electrolyte interface (SEI) at the anode is least inhibiting to ion flow. Therefore, this frequency was imitated with a square-wave, current pulse to ameliorate the sluggish SEI kinetics often blamed for onset of lithium deposition in low temperature charging. The magnitude of current was prescribed by the cell manufacturer and square pulses were applied until the voltage cutoff was reached. The charge was then topped off with a CV step and constant current discharged in the same manner as the conventionally charged 25°C and 0°C controls. The cells cycled at 25°C remained stable across 50 cycles: staying around 2.6A with 98% capacity retention. The pulsed cell and the cold cell begin with a capacity deficit due to enhanced cell impedance at the cold conditions. The capacity of the cold cell starts to fade, and at the 20th cycle a large drop in capacity is apparent. The drop off in capacity is due to plating of lithium within the cell, which is illustrated in the differential capacity assessment and computed tomography renderings of the cells after charging. The pulses cell does not exhibit fade like the cold cell, maintains a constant capacity, and has an impressive 99% capacity retention at the 50th cycle, which is comparable to the ambient cell. Figure 1. Charge/discharge behavior over 50 cycles for (a) constant current at 25°C (ambient), (b) pulsed charging at 0°C, and (c) constant current charging at 0°C. (d) Capacity retention over 50 cycles for the three charging and temperature conditions. Love, C.; Dubarry, M.; Reshetenko, T.; Devie, A.; Spinner, N.; Swider-Lyons, K.; Rocheleau, R., Lithium-Ion Cell Fault Detection by Single-Point Impedance Diagnostic and Degradation Mechanism Validation for Series-Wired Batteries Cycled at 0 °C. Energies 2018, 11 (4), 834.Love, C. T.; Baturina, O. A.; Swider-Lyons, K. E., Observation of Lithium Dendrites at Ambient Temperature and Below. Ecs Electrochem Lett 2015, 4 (2), A24-A27.Love, C. T.; Virji, M. B. V.; Rocheleau, R. E.; Swider-Lyons, K. E., State-of-health monitoring of 18650 4S packs with a single-point impedance diagnostic. Journal of Power Sources 2014, 266, 512-519. Figure 1

Densification of pure magnesium by spark plasma sintering-discussion of sintering mechanism

In this study, high-quantity pure magnesium was prepared by SPS, and the sintering densification mechanism was discussed by using numerical simulation and simultaneous experiment. Results show that a layer of dense magnesium oxide was formed at the surface of Mg particles, and the oxide reduction can be observed owing to the effect of oxide film removal in SPS. The high energy pulsed current flows preferentially through particle contact surfaces, which provides the conditions for the generation of micro-arc between particles and the temperature at the particles contact point can be up to 1979 °C. With the low pressure at the initial sintering stage, local high temperature induced by micro-arc makes the melting (even evaporation) appearance. At the same sintering temperature of 570 °C, the obvious difference in bending strength also demonstrates the significance of spark discharge in SPS. The formation process of sintering neck demonstrates that sintering process is the reflection of melting (even evaporation), diffusion and plastic deformation. In order to realize tiny area and high-quality connection between powder particles, an innovative powder sintering technology using high-frequency pulse electric current (High frequency pulse current assisted sintering) is proposed based on the enlightenment of the skin, proximity and arc discharge effect of high-frequency pulse current. This technology is also instructive for other alloys and engineering materials.

Nanosecond pulsed discharge-driven non-oxidative methane coupling in a plate-to-plate electrode configuration plasma reactor

In this work, we establish a set of reactor operation guidelines for efficient non-oxidative methane coupling (i.e., high olefins yield) in nanosecond pulsed discharges and plate-to-plate electrode configuration. The reactor performance analysis suggests that the operating conditions directly affect the bulk gas temperature, which in turn determines the plasma resistance and, subsequently, the energy channeled into the discharge. High performance is attained only at proper load-impedance matching, i.e. when operating in spark regime and applying i) moderate pulse frequencies (≤20 kHz) combined with moderate discharge gaps (≤3.5 mm) or ii) high pulse frequencies (>20 kHz) combined with high discharge gaps (>3.5 mm). Further, the electrode configuration itself significantly affects the reactor performance. When applying same operating conditions, the plate-to-plate configuration attains lower olefin (C2) yield than the co-axial one (~27% vs ~34%, respectively) since lesser energetic discharges are ignited (11 W vs 17 W), but ~20% lower energy is used due to lower electric energy dissipation into gas heating. The plate-to-plate configuration also features significantly higher performance stability and robustness in carbon formation, enabling an order-of-magnitude longer operating periods.

The Role of the Brain in the Pathogenesis and Physiology of Polycystic Ovary Syndrome (PCOS).

Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disorder, affecting at least 10% of women of reproductive age. PCOS is typically characterized by the presence of at least two of the three cardinal features of hyperandrogenemia (high circulating androgen levels), oligo- or anovulation, and cystic ovaries. Hyperandrogenemia increases the severity of the condition and is driven by increased luteinizing hormone (LH) pulse secretion from the pituitary. Indeed, PCOS women display both elevated mean LH levels, as well as an elevated frequency of LH pulsatile secretion. The abnormally high LH pulse frequency, reflective of a hyperactive gonadotropin-releasing hormone (GnRH) neural circuit, suggests a neuroendocrine basis to either the etiology or phenotype of PCOS. Several studies in preclinical animal models of PCOS have demonstrated alterations in GnRH neurons and their upstream afferent neuronal circuits. Some rodent PCOS models have demonstrated an increase in GnRH neuron activity that correlates with an increase in stimulatory GABAergic innervation and postsynaptic currents onto GnRH neurons. Additional studies have identified robust increases in hypothalamic levels of kisspeptin, another potent stimulator of GnRH neurons. This review outlines the different brain and neuroendocrine changes in the reproductive axis observed in PCOS animal models, discusses how they might contribute to either the etiology or adult phenotype of PCOS, and considers parallel findings in PCOS women.

Vagus Nerve Stimulation for Chronic Heart Failure: Differences in Therapy Delivery and Clinical Efficacy in ANTHEM-HF, INOVATE-HF, and NECTAR-HF

Background Vagus Nerve Stimulation (VNS) is meant to deliver Autonomic Regulation Therapy (ART) to neurological targets with sufficient neuromodulation (NM) to ameliorate chronic heart failure (CHF). VNS delivery consists of its intensity (a combination of pulse amplitude, pulse frequency, and pulse duration), polarity, duty cycle (DC; stimulation “on” time and “off” time), and mode (continuous, or intermittent and periodic). In the ANTHEM-HF Pilot Study patients with CHF and reduced ejection fraction (HFrEF), VNS intensity was up-titrated until a change in heart rate (HR) dynamics was objectively confirmed. This did not require any change in GDMT and was associated with significant improvements in LVEF, 6-minute walk distance (6MWD), Minnesota Living with HF (MLWHF) score, and HR variability. Methods Qualitative and quantitative analyses used data from peer-reviewed publications and other sources in the public domain to compare VNS delivery in ANTHEM-HF, INOVATE-HF, and NECTAR-HF. Results (Table): Up-titration of VNS intensity was attempted in all 3 studies. In contrast to ANTHEM-HF, INOVATE-HF aimed only at peripheral neural targets. VNS intensity was delivered at a lower pulse frequency, and had a variable DC as a consequence of R-wave synchronization and only intermittent, periodic stimulation. In NECTAR-HF VNS intensity was delivered at a higher pulse frequency, and this was associated with intolerable adverse off-target effects which restricted VNS up-titration. Significant improvements in EF, 6MWD, MLWHF, and SDNN occurred in ANTHEM-HF relative to the other studies. Conclusion VNS differed in ANTHEM-HF when compared to INOVATE-HF and NECTAR-HF. The neural targets, pulse frequencies for titration, and the DC for NM were different. VNS in ANTHEM-HF was clinically efficacious. The ongoing ANTHEM-HFrEF Pivotal Study uses a similar paradigm.

An AC-AC High Frequency Pulse Density Modulated Full Bridge Series Resonant Converter for Induction Heating Application

&lt;p class="Abstract"&gt;This paper deals with a new AC – AC single stage full bridge series resonant converter for induction heating application. The proposed system is simulated with high power density modulation technique to produce a output power of 1.8Kw.The main feature of the proposed converter is to reduce the total harmonic distortion produced in the output current for the switching frequency of 29Khz.Asymmetrical pulse density modulation technique is proposed to achieve maximum output power with less harmonic content. It is found that the THD of the proposed high power density modulated converter is 13.43%. Here, the validity of the proposed converter for domestic induction heating application is compared and summarized.&lt;/p&gt;

A reliable initial rotor position estimation method for sensorless control of interior permanent magnet synchronous motors

In this paper, a novel initial rotor position estimation method for reliable start-up of the IPMSM is presented. The proposed method combines the improved high frequency pulse signal injection with positive and negative d-axis current bias injection. Differing from the conventional initial rotor position detection scheme, the injection and the field-oriented control periods are separated in the proposed method. Therefore, the filters are not needed in the process of high-frequency response current and fundamental current extraction. The magnet polarity can be estimated by exciting the positive and negative d-axis currents. Afterwards, the peak values of d-axis current during the voltage injection period are accumulated to detect the rotor magnetic polarity. The proposed method can improve the reliability of the magnet polarity detection. Moreover, it is suitable for both the standstill rotor application and the free-running rotor application. The effectiveness of the proposed method is verified on a 1.5 kW IPMSM drive platform.