Precise Pulse Research Articles

Exploring the Potential of High-Power Impulse Magnetron Sputtering for Nitride Coatings: Advances in Properties and Applications

High-Power Impulse Magnetron Sputtering (HiPIMS) has emerged as an excellent technology for producing high-quality nitride coatings, such as aluminum nitride (AlN), titanium nitride (TiN), chromium nitride (CrN), and silicon nitride (SiN), and composite nitride coatings such as titanium aluminum nitride (TiAlN), TiAlNiCN, etc. These coatings are known for their exceptional hardness, thermal stability, and corrosion resistance. These make them ideal for high-performance applications. HiPIMS distinguishes itself by generating highly ionized plasmas that facilitate intense ion bombardment, leading to nitride films with superior mechanical strength, durability, and enhanced thermal properties compared to traditional deposition techniques. Critical HiPIMS parameters, including pulse duration, substrate bias, and ion energy, are analyzed for their influence on enhancing coating density, adhesion, and hardness. The review contrasts HiPIMS with other deposition methods, highlighting its unique ability to create dense, uniform coatings with improved microstructures. While HiPIMS offers substantial benefits, it also poses challenges in scalability and process control. This review addresses these challenges and discusses hybrid, bipolar, and synchronized HiPIMS solutions designed to optimize nitride coating processes. Hybrid HiPIMS, for instance, combines HiPIMS with other sputtering techniques like DCMS or RF sputtering to achieve balanced deposition rates and high-quality film properties. Bipolar HiPIMS enhances process stability and film uniformity by alternating the polarity, which helps mitigate charge accumulation issues. Synchronized HiPIMS controls precise pulse timing to maximize ion energy impact and improve substrate interaction, further enhancing the structural properties of the coatings. Hence, to pave the way for future research and development in this area, insights of the HiPIMS have been presented that underline the role of HiPIMS in meeting the demanding requirements of advanced industrial applications. Overall, this review article comprehensively analyzes the recent strategies and technological innovations in HiPIMS and highlights the significant potential of HiPIMS for advancing the nitride coating field.

A Physical Model of Quantum Bit Behavior Based on a Programmable FPGA Integrated Circuit

The rapidly developing field of quantum computing and the ongoing lack of widely available quantum computers create the need for scientists to build their simulators. However, mathematical simulation of such circuits usually ignores many aspects and problems found in real quantum systems. In this article, the authors describe a quantum bit emulator based on FPGA integrated circuits. In this case, FPGA technology provides real-time massive parallelism of the modeled physical phenomena. The modeled QUBIT is represented using a Bloch sphere. Its quantum state is set and modified only by precise pulses of an electrical signal, and with the help of similar pulses, it manifests its current state in real time. The constructed QUBIT was additionally equipped with decoherence mechanisms and with circuits that intentionally respond to internal and external noises that distort its current quantum state. This article presents and discusses how such a physically built emulator works.

Ethylendiaminetetrakis(1,10-phenanthroline)dicopper(II) chloride: Synthesis and application for voltammetric determination of doxycycline in real samples

The study describes on the preparation of a new homobinuclear mixed ligand complex µ-ethylendiaminetetrakis(1,10-phenanthroline)dicopper(II) chloridedihydrate (EP4Cu2CH2) from a previously reported complex chlorobis(1,10-phenanthroline)copper(II) chloridemonohydrate (CP2CuCH). The synthesis was checked by spectroscopy (UV–Vis, FT IR), CHN elemental analysis, Cu determination using ICP-OES, electrolytic conductivity, qualitative and quantitative chloride estimation, and melting point measurements. The new complex was applied for the modification of a glassy carbon electrode (poly(EP4Cu2CH2)/GCE) for determination of doxycycline (Doxy), (which belongs to a tetracycline antibiotic, mainly used for the treatment of a wide bacterial infections) by selective, accurate, and precise differential pulse voltammetric method. Electrode characterization revealed modification of the electrode surface by a conductive, and electroactive polymer film (poly(EP4Cu2CH2)/GCE) leading to improved effective electrode surface area. In contrast to the bare electrode, the appearance of two well-resolved irreversible oxidative peaks at much reduced potential with sevenfold current enhancement at poly(EP4Cu2CH2)/GCE showed the catalytic effect of the modifier towards Doxy. Differential pulse voltammetric current response of poly(EP4Cu2CH2)/GCE showed a linear dependence on the concentration of Doxy in the range 5 × 10−8 – 3.5 × 10−4 M with a detection limit of 3.5 × 10−9. The Doxy levels in four tablet brands were in the range 96.00–101.30 % of their labeled values. Spike recovery results in tablet, cow milk, and human urine samples were 98.90–100.73 %, 98.30–100.00 %, and 98.50–100.54 %, respectively. Based on the innovative mixed ligand poly(EP4Cu2CH2)/GCE, the interference recovery results about 4.79 % error, lesser LoD, and a broader concentrationrange than most previously published methods validated the present method’s potential applicability with excellent accuracy and sensitivity for Doxy determination in various real samples with complex matrix.

Commissioning of a modulated pulse-power magnetron sputtering system for depositing niobium thin films

A modulated pulse-power magnetron sputtering system (MPPMS) was commissioned and used to deposit niobium on copper. MPPMS utilizes a modulated pulse train with high peak-to-average energy ratios, thereby increasing the energy density leading to the production of the energetic ions. The MPPMS modulator was designed and constructed based on large voltage/current IGBT modules, which can be externally modulated, produce bi-polar waveforms, and are readily available. A high voltage power supply provides moderate current to the IGBT module to create the precise pulse structure. The MPPMS system was used to deposit ∼1 μm thick, niobium film on a copper substrate held at ∼77 K to minimize Nb atom surface diffusion and maximize intrinsic film energy. The Nb film had an average grain size of ∼8 nm.

Stretchable Iontronic Tactile Sensing Fabric.

The iontronic tactile sensing modality has garnered significant attention due to its exceptional sensitivity, immunity to noise, and versatility in materials. Recently, various formats of iontronic tactile sensors have been developed, including droplets, polymer films, paper, ionic gels, and fabrics. However, the stretchability of the current iontronic pressure sensing fabric is inadequate, hindered by the limited stretchiness of the ionic functional fabric. Incorporating a stretchable tactile sensing implement could enhance the wear comfortability by preventing relative movement and ensuring intimate contact between the sensor and the skin. The research focuses on the development of a stretchable iontronic pressure sensing (SIPS) fabric for monitoring diverse aspects of body health and movement in wearable applications. The tactile sensing structure is generated at the iontronic interface between highly stretchable ionic and conductive fabrics. In particular, the ionic fabric is prepared by coating a layer of polyurethane/ionic liquid gel onto a Spandex fabric. To showcase its remarkable sensitivity, stretchability, and ability to detect diverse body information, several application scenarios have been demonstrated including an elastic wristband for precise pulse wave detection, a flexible belt with multitactile sensing channels for respiration and motion tracking purposes, and a stretchable fabric cuff equipped with a high-resolution sensing array comprising 32 × 32 units for accurate gesture recognition.

μDOSE+: Environmental radioactivity and dose rate measurement system with active shielding boosted by machine learning

The μDOSE+ is a novel measurement system designed for environmental radioactivity measurements and trapped charge dating applications. This study describes improvements integrated into the μDOSE+ system. These enhancements include a redesigned counting chamber equipped with an active radon removal system, passive shielding and an active shielding module that is further refined by machine learning algorithms for precise pulse classification. These advancements collectively lead to a significant reduction in background in the β counting window, improved α and β counting efficiency and easier sample handling. This is demonstrated through a comparative analysis with its predecessor, the classical μDOSE system.

A comparative study on the degradation of carbamazepine by UV laser/chlorine and UV laser/PS processes: Performance and mechanisms

Residual carbamazepine (CBZ) in water is difficult to remove through conventional treatment processes, threatening the safety of drinking water. Ultraviolet-based advanced oxidation processes (UV-AOPs) have shown promise in removing refractory organic pollutants, while the low energy and efficiency of traditional mercury lamps hinder their practical applications. In this study, the performance and mechanism of an intensive-energy light source, UV laser, were systematically explored in UV-AOPs (laser/chlorine, laser/persulfate (PS)). It was found that UV laser exhibited a significantly activating ability for chlorine and PS due to its precise wavelength and high pulse energy. When exposed to UV laser (266 nm, 4.2 mW/cm2) combined with 200 μM chlorine and PS, the kinetic rate constants for the degradation of 10 μM CBZ were determined to be 3.160 × 10-3 and 1.227 × 10-3 s−1, respectively. The degradation of CBZ was dominated by hydroxyl radicals (60.98 %) and sulfate radicals (23.15 %) in laser/PS system, while in laser/chlorine system, hydroxyl radicals (54.90 %), chlorine radicals (27.43 %), and chlorine oxide radicals (13.81 %) were primary reactive species. Furthermore, both the laser/chlorine and laser/PS systems demonstrated compatibility with a wide pH range of 5.0–9.0 and high resistance to anionic interference. Moreover, the electrophilic and nucleophilic sites of CBZ and energy barrier of the initial reaction were calculated based on the density functional theory (DFT). Additionally, the degradation pathways of CBZ and the toxicity of transformation products in laser/chlorine and laser/PS processes were proposed and evaluated. These results demonstrated that the UV laser-based processes exhibited promising prospects in eliminating refractory organic pollutants in water treatment.

A New Five-Level Switched-Capacitor-Based Transformer-less Common-Grounded Grid-Tied Inverter

This paper proposes a new switched-capacitor grid-tied inverter. The proposed topology can eliminate leakage current using a common-grounded strategy. Also, the proposed topology generates a five-level output voltage waveform using a single input dc source with a voltage boosting factor of 2. This structure uses six power switches, two diodes, and two self-balanced capacitors. The proposed inverter has some advantages such as a common-grounded feature, eliminated leakage current, and voltage boosting feature with single-stage energy conversion operation. Also, the proposed topology can support both active and reactive powers and generate a perfect sinusoidal output current injected into the grid. Also, to control both active and reactive powers an efficient control strategy is applied. To generate the precise gate pulses for the power switches, the introduced efficient control strategy is applied. Also, comprehensive discussions on the operating modes of the proposed inverter, Capacitor charging current analysis, the control technique, and design considerations are presented. To show the advantages and differences of the proposed inverter with some other recently presented switched-capacitor-based grid-tied inverters a comparison study is considered. Finally, to validate the performance and feasibility of the proposed inverter, various experimental results based on a 620 W experimental prototype are presented.

SmartQCache: Fast and Precise Pulse Control With Near-Quantum Cache Design on FPGA

SmartQCache: Fast and Precise Pulse Control With Near-Quantum Cache Design on FPGA

Precise Pulse Processing Discrimination between Alpha and Neutron Radiation Using Grey Wolf and Whale Optimization Algorithms

Precise Pulse Processing Discrimination between Alpha and Neutron Radiation Using Grey Wolf and Whale Optimization Algorithms

Autonomous Distribution of Programmable Multiqubit Entanglement in a Dual-Rail Quantum Network.

We propose and analyze a scalable and fully autonomous scheme for preparing spatially distributed multiqubit entangled states in a dual-rail waveguide QED setup. In this approach, arrays of qubits located along two separated waveguides are illuminated by correlated photons from the output of a nondegenerate parametric amplifier. These photons drive the qubits into different classes of pure entangled steady states, for which the degree of multipartite entanglement can be conveniently adjusted by the chosen pattern of local qubit-photon detunings. Numerical simulations for moderate-sized networks show that the preparation time for these complex multiqubit states increases at most linearly with the system size and that one may benefit from an additional speedup in the limit of a large amplifier bandwidth. Therefore, this scheme offers an intriguing new route for distributing ready-to-use multipartite entangled states across large quantum networks, without requiring any precise pulse control and relying on a single Gaussian entanglement source only.

Passive Electrical and Optical Methods of Ultra-Short Pulse Expansion for Event Timer-Based TDC in PPM Receiver

The energy efficiency of a communication system using pulse position modulation (PPM) can be increased by reducing the duration of the pulses transmitted over the communication channel to several tens of picoseconds. The employment of an event timer device as a time-to-digital converter (TDC) for demodulation allows the use of PPM with many pulse positions and achieves competitive data transfer speeds. However, along with several-picosecond accuracy of modern event timers, they require a pulse duration of several hundred picoseconds for precise detection. This research is devoted to developing passive techniques for precise pulse expansion from tens of picoseconds to hundreds of picoseconds. We propose two methods: the electrical method, which employs a microstrip low-pass filter (LPF), and the optical method, which uses fiber Bragg grating (FBG). This research offers a detailed analysis of distortion-free pulse expansion requirements, the design of prototypes meeting these requirements, and experimental design verification. Theoretical background, mathematical models, and results of experimental validation of the proposed pulse expansion methods within the laboratory transmitted reference pulse-position modulation (TR-PPM) communication system are provided.

Low voltage mapping in atrio-ventricular nodal reentry tachycardia ablation: safety and efficacy in a single center experience

Abstract Background Atrio-ventricular nodal reentry tachycardia (AVNRT) is one of the most common supraventricular arrhythmias. Transcatheter ablation is the first-choice strategy for its treatment. Despite various ablation techniques, using different signal analyses and different energy sources, the reported incidence rate of AVNRT recurrences and high-grade or complete atrioventricular block are about 5% and 1% respectively. Voltage mapping for slow pathway localization is a novel technique for the treatment of AVNRT, that may increase procedural safety and effectiveness, particularly in pediatric patients. Purpose To evaluate the safety and efficacy of ablation of slow conduction pathway identified via three-dimensional voltage mapping of Koch’s triangle. Methods 108 consecutive patients (45% male, mean age 58.6±15.4 years) scheduled for AVNRT ablation in our center underwent three-dimensional voltage mapping of the right atrial septum and Koch’s triangle. Voltage map was aimed at detecting an area of low voltage (voltage bridge) below the His bundle (adjusting the high-voltage slider to 1,5 mV), corresponding to the slow conduction pathway. Focusing on this target, we evaluated the number of radiofrequency (RF) pulses and RF time application for effective ablation of the slow conduction pathway defined by accelerated junctional rhythm (AJR) induction during RF delivery and absence of post-ablative AVNRT inducibility. After RF ablation, all patients underwent clinical evaluation every 3 months to identify AVNRT recurrences. Results Voltage mapping was performed in all patients. The mean duration of mapping was 5.7±3.8 minutes. In all patients, a low voltage bridge could be identified. Using this target, RF was delivered until AJR was elicited (mean number of RF pulses at 30W, 50°C = 1.5±1.1; mean time to AJR: 25±12 s). After successful ablation of the slow conduction pathway, AVNRT was no more inducible. No atrioventricular conduction defect (atrioventricular block of any grade) occurred after RF ablation in any patient (AH pre vs. AH post: 148.5±22.8 ms vs. 153.6±17.8 ms, p=n.s.; HV pre vs. HV post: 20.5±18.7 ms vs. 21.8±17.3 ms, p=n.s.; Wenkebach point pre vs. Wenkebach point post: 320.4±45.3 ms vs. 326.2±38.7 ms, p=n.s.). All patients were discharged without antiarrhythmic drug therapy. Overall, during a 2-year follow up, 4 patients had a recurrence of AVNRT (incidence rate of recurrences: 0.025/year). Conclusions Voltage mapping can easily identify the low voltage bridge area of Koch’s triangle as a target for slow pathway ablation. RF ablation of the slow pathway identified in this way is safe and effective. Success in slow pathway ablation can be achieved with a low number of very precise RF pulses. This approach can prevent the risk of ablation-related atrioventricular conduction defects and reduce the risk of AVNRT recurrences.

Infrared Resonance Tailoring of Individual Split‐Ring Resonators with Phase‐Change Materials by Locally Changing the Dielectric Surrounding of the Antenna Hotspots

AbstractFor miniaturized active metasurfaces, resonance tuning of nanoantennas is a key ingredient. Phase‐change materials (PCMs) have been established as prime candidates for non‐volatile resonance tuning enabled by a change in the refractive index around nanoantennas. Conventionally, this tuning is induced by annealing the entire sample equally and does not allow changes on a meta‐atom level. Recently, it is demonstrated that individual rodantenna resonances can be adjusted by addressing each meta‐atom locally with precise laser pulses and switching the PCM there. However, simultaneously controlling several different modes remains elusive. In this work, PCM‐covered aluminum split‐ring resonators (SRRs) are switched locally to tune both the electric dipole resonances as well as the magnetic dipole resonances. By selectively switching the PCM at different hotspots of the SRRs, both resonances can be tuned individually. Finally, the field enhancement in the magnetic resonance allows continuous tuning of surface‐enhanced infrared absorption of native SiO2. This work serves as a proof of principle for sophisticated resonance tuning via changes in the refractive index at the hotspots of the selected antennas enabling fine‐tuning functionalities on a meta‐atom level and allows for post‐fabrication adjustments of metasurfaces.

High-order harmonic generation from a thin film crystal perturbed by a quasi-static terahertz field

Studies of laser-driven strong field processes subjected to a (quasi-)static field have been mainly confined to theory. Here we provide an experimental realization by introducing a bichromatic approach for high harmonic generation (HHG) in a dielectric that combines an intense 70 femtosecond duration mid-infrared driving field with a weak 2 picosecond period terahertz (THz) dressing field. We address the physics underlying the THz field induced static symmetry breaking and its consequences on the efficient production/suppression of even-/odd-order harmonics, and demonstrate the ability to probe the HHG dynamics via the modulation of the harmonic distribution. Moreover, we report a delay-dependent even-order harmonic frequency shift that is proportional to the time derivative of the THz field. This suggests a limitation of the static symmetry breaking interpretation and implies that the resultant attosecond bursts are aperiodic, thus providing a frequency domain probe of attosecond transients while opening opportunities in precise attosecond pulse shaping.

Development of a flexible embedded neurostimulator for animal robots

The neural stimulator is a core component of animal robots. While the control effect of animal robots is influenced by various factors, the performance of the neural stimulator plays a decisive role in regulating animal robots. In order to optimize animal robots, embedded neural stimulators had been developed using flexible printed circuit board technology. This innovation not only enabled the stimulator to generate parameter-adjustable biphasic current pulses through control signals, but also optimized its carrying mode, material, and size, overcoming the disadvantages of traditional backpack or head-inserted stimulators, which have poor concealment and are prone to infection. Static, in vitro, and in vivo performance tests of the stimulator demonstrated that it not only had precise pulse waveform output capability, but also was lightweight and small in size. It had excellent in vivo performance in both laboratory and outdoor environments. Our study has high practical significance for the application of animal robots.

Spectrum-tailored random fiber laser towards ICF laser facility

Broadband low-coherence light is considered to be an effective way to suppress laser plasma instability. Recent studies have demonstrated the ability of low-coherence laser facilities to reduce back-scattering during beam–target coupling. However, to ensure simultaneous low coherence and high energy, complex spectral modulation methods and amplification routes have to be adopted. In this work, we propose the use of a random fiber laser (RFL) as the seed source. The spectral features of this RFL can be carefully tailored to provide a good match with the gain characteristics of the laser amplification medium, thus enabling efficient amplification while maintaining low coherence. First, a theoretical model is constructed to give a comprehensive description of the output characteristics of the spectrum-tailored RFL, after which the designed RFL is experimentally realized as a seed source. Through precise pulse shaping and efficient regenerative amplification, a shaped random laser pulse output of 28 mJ is obtained, which is the first random laser system with megawatt-class peak power that is able to achieve low coherence and efficient spectrum-conformal regenerative amplification.

13CO2-labelling and Sampling in Algae for Flux Analysis of Photosynthetic and Central Carbon Metabolism.

The flux in photosynthesis can be studied by performing 13CO2 pulse labelling and analysing the temporal labelling kinetics of metabolic intermediates using gas or liquid chromatography linked to mass spectrometry. Metabolic flux analysis (MFA) is the primary approach for analysing metabolic network function and quantifying intracellular metabolic fluxes. Different MFA approaches differ based on the metabolic state (steady vs. non-steady state) and the use of stable isotope tracers. The main methodology used to investigate metabolic systems is metabolite steady state associated with stable isotope labelling experiments. Specifically, in biological systems like photoautotrophic organisms, isotopic non-stationary 113C metabolic flux analysis at metabolic steady state with transient isotopic labelling (13C-INST-MFA) is required. The common requirement for metabolic steady state, alongside its very short half-timed reactions, complicates robust MFA of photosynthetic metabolism. While custom gas chambers design has addressed these challenges in various model plants, no similar tools were developed for liquid photosynthetic cultures (e.g., algae, cyanobacteria), where diffusion and equilibration of inorganic carbon species in the medium entails a new dimension of complexity. Recently, a novel tailor-made microfluidics labelling system has been introduced, supplying short 13CO2 pulses at steady state, and resolving fluxes across most photosynthetic metabolic pathways in algae. The system involves injecting algal cultures and medium containing pre-equilibrated inorganic 13C into a microfluidic mixer, followed by rapid metabolic quenching, enabling precise seconds-level label pulses. This was complemented by a 13CO2-bubbling-based open labelling system (photobioreactor), allowing long pulses (minutes-hours) required for investigating fluxes into central C metabolism and major products. This combined labelling procedure provides a comprehensive fluxome cover for most algal photosynthetic and central C metabolism pathways, thus allowing comparative flux analyses across algae and plants.

Electroporation-Mediated CRISPR/Cas9 Genome Editing in Rat Zygotes.

Genetic engineering in the rat has been revolutionized by the development of CRISPR-based genome editing tools. Conventional methods for inserting genome editing elements such as CRISPR/Cas9 reagents into rat zygotes include cytoplasmic or pronuclear microinjections. These techniques are labor-intensive, require specialized micromanipulator equipment, and are technically challenging. Here, we describe a simple and effective method for zygote electroporation in which CRISPR/Cas9 reagents are introduced into rat zygotes via pores produced by precise electrical pulses applied to the cells. Zygote electroporation allows for high-throughput efficient genome editing in rat embryos.

Proper technique of lower extremity pulse examination: a lost art.

A properly performed pulse examination can provide an accurate assessment of the arterial circulation to the lower extremity. However, increasing availability of non-invasive vascular laboratory testing, CT-angiography, magnetic resonance angiography, and catheter-based arteriography has deemphasized the use and teaching to student and resident physicians of classic techniques to examine lower extremity pulses. Clinical evaluation and accurate pulse examination may eliminate the need for these often unnecessary and expensive tests to evaluate arterial insufficiency. In this report, we describe our technique for precise lower extremity pulse examination to teach younger physicians and remind more experienced ones of the value and necessity of this critical aspect of a physical examination.