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AbstractObjectiveDesignStudy SampleResultsConclusions\nHIGHLIGHTSThe present study aimed to objectively assess the charge integration efficiency (CIE) of the auditory nerve using electrically-evoked stapedial reflex threshold (eSRT) measurements in paediatric cochlear implant users.The eSRT was estimated in two ways: by keeping pulse width constant while increasing pulse amplitude and vice versa. The electrical dynamic range (EDR) obtained for eSRT was measured with increasing pulse amplitude (EDRPA) and pulse width (EDRPW) by calculating the difference in charge units between eSRT and behavioural thresholds; further, CIE was estimated.Fifteen paediatric cochlear implant users.EDRPW was 1.4 to 1.7 times larger than EDRPA. The EDRPW was significantly greater than the EDRPA. A significant correlation was observed between both EDR measures. However, the CIE measure did not significantly correlate with the behavioural threshold. Further, there was no significant effect of electrode location on the CIE.The CIE estimated with objective measures such as eSRT is comparable to those estimated using behavioural loudness judgments. eSRT can serve as a quick method to estimate the CIE, which can be easily implemented in the paediatric population. The CIE could be a valuable tool for differentiating electrodes with excellent and poor charge integration efficiency.In cochlear implants, loudness perception can be increased with an increase in pulse amplitude or width.Charge integration efficiency can be a valuable measure to assess the ability of the auditory nerve to integrate the charge over time.Electrically evoked stapedial reflex measurement can be used as an objective method to measure charge integration efficiency.In cochlear implants, loudness perception can be increased with an increase in pulse amplitude or width.Charge integration efficiency can be a valuable measure to assess the ability of the auditory nerve to integrate the charge over time.Electrically evoked stapedial reflex measurement can be used as an objective method to measure charge integration efficiency. [ABSTRACT FROM AUTHOR]

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When using impact testing machine to evaluate products, it often fails to reach the peak acceleration and pulse width of the specified pulse waveform, and it needs to be adjusted by the experience of testers and repeated experiments. Therefore, in order to accurately predict the shock waveform before the shock test and save debugging time and resources, a method was proposed to predict the peak acceleration and pulse width of the waveform using a nonlinear regression model. First, the Mooney-Rivlin model was used to fit the hyper elastic intrinsic parameters of the waveform generator, a finite element model of the shock system was established, and shock tests were conducted to verify the accuracy of the finite element model. Then, the finite element and orthogonal experimental methods were used to study the effects of parameters such as hardness, thickness, diameter and shock table drop height of the waveform generator on the shock waveform. Finally, the power function was chosen as the functional form of multivariate nonlinear regression and the less significant factor terms were eliminated to establish the prediction model of peak acceleration and pulse width of the shock waveform, and the accuracy of the prediction model was verified by the shock test. The research results show that the thickness and diameter of the waveform generator and their interaction are the main factors affecting the shock waveforms. Comparing the predicted values of the regression model with the shock test data, it is found that the error between the two is not more than 10%, which indicates that the established regression prediction model of impact waveform is effective. [ABSTRACT FROM AUTHOR]

The present study optimize the impact of full width at half maximum (FWHM) and laser pulse width (PW) on the laser intensity. This investigation entailed the assessment of a laser dye exhibiting nonlinear characteristics, which demonstrated an absorption spectrum aligned with the used wavelength. The optimizing employed a semiconductor laser operating at a precise wavelength of 657 nm. The laser has undergone many improvements, resulting in its conversion into a pulse-type laser. The pulse frequency of the laser was increased to a maximum value of 150 kHz, while the pulse width exhibited a range of variability ranging from 1 to 99%. The aforementioned modification was achieved by employing a pulse width modulation circuit that had been specifically constructed for this particular purpose. The empirical evidence presented in the study supports a correlation between FWHM and the pulse width (PW). Indeed, each increase in the FWHM implies a commensurate increase in the pulse width (PW). Study of the characteristics of lasers has revealed a positive correlation between the FWHM and the laser intensity. Based on the empirical data obtained, it is apparent that there exists an inverse relationship between the duration of the laser pulse and the intensity of the laser. The observed behaviors can be attributed to the inherent characteristics of the laser dye, which exhibit heightened nonlinear features with greater intensities. The augmentation of laser pulse strength leads to the expansion of the spectral range of the dye. [ABSTRACT FROM AUTHOR]

Affected by environmental states and power supply parameters, the discharge mode of surface dielectric barrier discharge (SDBD) plasma may gradually transfer from O3 mode to NO x mode, resulting in various gas-phase species for different applications. Despite the intensive study of attempts to control this discharge mode transition by changing discharge conditions and power excitations in recent years, the effects of the pulse rise time and the pulse width on the discharge mode transition have not been discussed. In the present study, a SDBD was excited by repetitive pulses with different pulse rise times or pulse widths, and the time-varying concentrations of key long-lived species (O3 and NO2) were quantified. The results demonstrated that it was possible to modulate the discharge mode by adjusting pulse rise time/pulse width. The quenching of O3 was observed to occur at a faster rate and the mode transition was noted to occur at an earlier point in time as the pulse rise time decreased from 225 ns to 125 ns and the pulse width increased from 0.5 μ s to 4 μ s. The employment of a zero-dimensional model for the analysis of plasma chemical kinetics revealed that the reduction in pulse rise time and the prolongation of pulse width resulted in an increase in the mean vibrational energy of N2(v) and a more rapid electrode temperature rise caused by plasma heating. The former enhanced the generation of NO, while the latter accelerated the thermal decomposition of O3, thereby promoting the speed of mode transition. [ABSTRACT FROM AUTHOR]

The spatially resolvable multicolored microrods have potential applications in many fields. However, achieving spatially resolved multicolor luminescence tuning on the microrod with a fixed composition remains a daunting challenge. Herein, a strategy is proposed that allows for the tuning of spatially resolved, multicolored upconversion (UC) luminescence (UCL) along a 1D heterogeneous microrod by modifying the pulse width of an external laser. NaYbF4:1 % Ho is identified as an UCL color‐adjustable material, exhibiting pulse width‐dependent multicolored UCL, resulting in a significant regulation of the red/green (R/G) ratio from 0.1 to 10.3 as the pulse width is varied from 0.1 to 10 ms. Such variability can be ascribed to differences in the number of photons incident upon the microrod throughout the period necessary for the UC process to occur. Additionally, NaYbF4:1 %Tm and NaYF4:20 %Yb,1 %Ho are employed as materials that emit blue and green light, respectively, with their UCL colors largely unaffected by changes in the pulse width. Subsequently, a tip‐modified epitaxial growth method is utilized to integrate both UCL color‐adjustable and non‐adjustable segments within the same microrod. Comparing with single‐color or fixed multicolor microrods, our developed multisegmented emissive color adjustable 1D heterogeneous microrods have unique optical characteristics and can carry more optical information. [ABSTRACT FROM AUTHOR]

Nanosecond pulsed electric fields (nsPEFs) have recently shown promise as a cancer therapy. Although nsPEF‐induced apoptotic responses have been observed, the stress on individual cell components has not been quantified. Therefore, the authors built a cell equivalent circuit, including mitochondria, to quantitatively calculate the voltage, electric field, and electrical energy applied to the cell components in the frequency domain. Additionally, pulse width and electrical energy changed in mitochondrial membrane potential over time. The results indicated that the change of pulsed voltage switched the cell stimulation pathway, resulting in different mitochondrial membrane potentials over time. The frequency response analysis confirmed that the potential on mitochondrial membranes increased under shorter pulse width conditions. This suggested that the frequency analysis provided in this paper is useful for relating the site of cellular stimulation to induce physiological effects. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Experiments on the cleaning of primer coatings and composite coatings were carried out by millisecond pulsed CO2 laser and nanosecond pulsed fiber laser, the dynamic behavior during the cleaning process was observed by high-speed camera and infrared thermal imager, and the micro- and macro-morphologies of the surface of the samples after cleaning were analyzed. After using millisecond pulsed CO2 laser to clean the paint coating, there are residual combustion products, and it is easy to thermally deform the substrate. When using nanosecond pulsed fiber laser to clean the primer coating, the laser energy can be precisely controlled to avoid damage to the substrate, but it is difficult to remove composite coatings in a single scan. Using 300 W nanosecond pulsed laser for multiple scans can remove thicker paint coatings with less damage to the substrate, but the cleaning efficiency is greatly reduced. For this, a new method of multi-laser combined cleaning is proposed. The composite coatings are thinned with a 200 W millisecond pulsed laser, and then the final cleaning is done by a 200 W nanosecond pulsed laser, and a clean substrate surface without visible damage is obtained. After cleaning, the coating residue rate is 0.965%, the surface roughness is 3.19 μm, and the surface contact angle is 33.3°, which is conducive to the reattachment of the subsequently applied coatings. [ABSTRACT FROM AUTHOR]

The quality of pump pulse in few-mode-fiber Brillouin optical time domain reflectometry (FMF-BOTDR) is vital for the spontaneous Brillouin scattering of modes LP01 and LP11 because it is the comprehensive effect of the main laser linewidth and pulse width, which is firstly discussed as we know. Numerical and experimental analysis are made for the amplitude and linewidth distribution, corresponding to the signal–noise ratio (SNR) and frequency resolution in BOTDR, respectively. Simulation shows the linewidths and peak values of Brillouin scattering have the same tendency for the LP01 mode and LP11 mode when the laser linewidth is less than 1 MHz but decreases slowly until they are the same when the laser linewidth is wider than 1 MHz. With the pulse width widening, the Brillouin linewidths for LP01 and LP11 modes both decrease sharply, almost to the natural linewidth of fiber 41 MHz and 35 MHz. Experimental results show that the amplitude distribution for the LP01 mode is always larger than for the LP11 mode if the main laser has the same linewidth and the frequency fluctuation is at least 2 MHz with the fiber laser and LP11 mode. The above results could provide improved sensing resolution for FMF-BOTDR sensing system. [ABSTRACT FROM AUTHOR]

High-power pulse magnetron sputtering is a new type of magnetron sputtering technology that has advantages such as high peak power density and a high ionization rate compared to DC magnetron sputtering. In this paper, we report the effects of different pulse widths on the current waveform and plasma spectrum of target material sputtering, as well as the structure and properties of Cu films prepared under the same sputtering voltage and duty cycle. Extending the pulse width can make the sputtering enter the self-sputtering (SS) stage and improve the ion quantity of sputtered particles. The Cu film prepared by HiPIMS with long pulse width has higher bond strength and lower electrical resistivity compared to the Cu film prepared by short pulse width. In terms of microstructure, the Cu film prepared by HiPIMS with the long pulse width has a larger grain size and lower micro-surface roughness. When the pulse width is bigger than 200 μs, the microstructure of the Cu film changes from granular to branched. This transformation reduces the interface on the Cu film, further reducing the resistivity of the Cu film. Compared to short pulses, long pulse width HiPIMS can obtain higher quality Cu films. This result provides a new process approach for preparing high-quality Cu films using HiPIMS technology. [ABSTRACT FROM AUTHOR]

Background: Pulse width, which can reflect qi, blood excess, and deficiency, has been used for diagnosing diseases and determining the prognosis in traditional Chinese medicine (TCM). This study aimed to devise an objective method to measure the pulse width based on an array pulse diagram for objective diagnosis. Methods: The channel 6, the region wherein the pulse wave signal is the strongest, is located in the middle of the pulse sensor array and at the guan position of cunkou during data collection. Therefore, the main wave (h1) time of the pulse wave was collected from the channel 6 through calculation. The left h1 time was collected from the remaining 11 channels. The amplitudes at these time points were extracted as the h1 amplitudes for each channel. However, the pulse width could not be calculated accurately at 12 points. Consequently, a bioharmonic spline interpolation algorithm was used to interpolate the h1 amplitude data obtained from the horizontal and vertical points, yielding 651 (31 × 21) h1 amplitude data. The 651 data points were converted into a heat map to intuitively calculate the pulse width. The pulse width was calculated by multiplying the number of grids on the vertical axis with the unit length of the grid. The pulse width was determined by TCM doctors to verify the pulse width measurement accuracy. Meanwhile, a color Doppler ultrasound examination of the volunteers' radial arteries was performed and the intravascular meridian widths of the radial artery compared with the calculated pulse widths to determine the reliability. Results: The pulse width determined using the maximal h1 amplitude method was comparable with the radial artery intravascular meridian widths measured using color Doppler ultrasound. The h1 amplitude was higher in the high blood pressure group and the pulse width was greater. Conclusions: The pulse width determined using the maximal h1 amplitude was objective and accurate. Comparison between the pulse widths of the normal and high blood pressure groups verified the reliability of the method. [ABSTRACT FROM AUTHOR]

LiDAR has high accuracy and resolution and is widely used in various fields. In particular, phase-modulated continuous-wave (PhMCW) LiDAR has merits such as low power, high precision, and no need for laser frequency modulation. However, with decreasing signal-to-noise ratio (SNR), the noise on the signal waveform becomes so severe that the current methods to extract the time-of-flight are no longer feasible. In this paper, a novel method that uses deep neural networks to measure the pulse width is proposed. The effects of distance resolution and SNR on the performance are explored. Recognition accuracy reaches 81.4% at a 0.1 m distance resolution and the SNR is as low as 2. We simulate a scene that contains a vehicle, a tree, a house, and a background located up to 6 m away. The reconstructed point cloud has good fidelity, the object contours are clear, and the features are restored. More precisely, the three distances are 4.73 cm, 6.00 cm, and 7.19 cm, respectively, showing that the performance of the proposed method is excellent. To the best of our knowledge, this is the first work that employs a neural network to directly process LiDAR signals and to extract their time-of-flight. [ABSTRACT FROM AUTHOR]

Background: To maximize clinical benefit and minimize stimulation-induced side effects, optimising deep brain stimulation (DBS) parameters is paramount. Recent literature suggests a potential benefit of short pulse width DBS (spDBS; ≤40 μs) over conventional pulse width DBS (cDBS; ≥60 μs) in movement disorders. Objective: To compare therapeutic window (TW), therapeutic and side effects and energy consumption of spDBS and cDBS in movement disorders. Methods: We systematically searched Medline, Embase, Cochrane Library and Web of Science. Appropriate paired analyses were performed. Results: Nine Parkinson's disease (PD) (143 patients), 4 essential tremor (ET) (26 patients) and no dystonia studies were included in the meta-analysis. TW defined as therapeutic amplitude range was larger with spDBS vs. cDBS in PD (standardized mean difference (SMD) = -1.04, p

To examine the association between pulse width and HRQoL measured within one week after electroconvulsive therapy (ECT) and at six-month follow-up in patients with unipolar or bipolar depression. This was an observational register study using data from the Swedish National Quality Registry for ECT (2011–2019). Inclusion criteria were: age ≥18 years; index treatment for unipolar/bipolar depression; unilateral electrode placement; information on pulse width; EQ-5D measurements before and after ECT. Multiple linear regressions were performed to investigate the association between pulse width (<0.5 ms; 0.5 ms; >0.5 ms) and HRQoL (EQ-5D-3L index; EQ VAS) one week after ECT (primary outcome) and six months after ECT (secondary outcome). The sample included 5,046 patients with unipolar (82%) or bipolar (18%) depression. At first ECT session, 741 patients (14.7%) had pulse width <0.5 ms, 3,639 (72.1%) had 0.5 ms, and 666 (13.2%) had >0.5 ms. There were no statistically significant associations between pulse width and HRQoL one week after ECT. In the subsample of patients with an EQ-5D index recorded six months after ECT (n = 730), patients receiving 0.5 ms had significantly lower HRQoL (−0.089) compared to <0.5 ms, after adjusting for demographic and clinical characteristics (p =.011). The corresponding analysis for EQ VAS did not show any statistically significant associations. No robust associations were observed between pulse width and HRQoL after ECT. On average, significant improvements in HRQoL were observed one week and six months after ECT for patients with unipolar or bipolar disease, independent of the pulse width received. [ABSTRACT FROM AUTHOR]

Graphite films are frequently used in the thermal interface materials (TIM) of thermal dissipation due to its high thermal conductivity. However, accurately measuring the thermal diffusivity of graphite films requires careful consideration of key parameters. In this study, four typical graphite films were analyzed to identify these parameters. The results revealed that pulse width was the most important parameter in accurately measuring thermal diffusivity. Specifically, when the pulse width was less than 1.8% of the half-heating time, thermal diffusivity measurements were more accurate. Conversely, when the pulse width exceeded 1.8% of the half-heating time, heating curves were affected, resulting in a gradual decrease in thermal diffusivity. Additionally, pulse voltage had little effect on thermal diffusivity measurements. These findings provide important guidance for accurately characterizing the thermal properties of graphite films and can inform the accurate measurement and development of efficient thermal interface materials. [ABSTRACT FROM AUTHOR]

To maximize clinical benefit and minimize stimulation-induced side effects, optimising deep brain stimulation (DBS) parameters is paramount. Recent literature suggests a potential benefit of short pulse width DBS (spDBS; ≤40 μs) over conventional pulse width DBS (cDBS; ≥60 μs) in movement disorders. To compare therapeutic window (TW), therapeutic and side effects and energy consumption of spDBS and cDBS in movement disorders. We systematically searched Medline, Embase, Cochrane Library and Web of Science. Appropriate paired analyses were performed. Nine Parkinson's disease (PD) (143 patients), 4 essential tremor (ET) (26 patients) and no dystonia studies were included in the meta-analysis. TW defined as therapeutic amplitude range was larger with spDBS vs. cDBS in PD (standardized mean difference (SMD) = -1.04, p < 0.001) and ET (SMD = −0.71, p < 0.001), but the TW in terms of charge per pulse (CPP) did not differ. In PD, no differences were found in therapeutic and side effects (MDS-UPDRS-III, speech and gait, dyskinesia, non-motor symptoms and quality of life). In ET, Fahn-Tolosa-Marin Tremor Rating Scale was lower with spDBS vs. cDBS (SMD = 0.36, p < 0.001). A qualitative analysis suggested fewer stimulation-induced side effects with spDBS. CPP was lower with spDBS vs. cDBS in PD (SMD = 0.79, p < 0.001) and ET (MD = 46.46 nC, p < 0.001), but real-world data on battery longevity are lacking. Although spDBS enlarges the TW as a wider amplitude range in both PD and ET, it does not alter TW defined by CPP. The therapeutic efficacy of spDBS is not different from cDBS in PD, but spDBS apparently induces more tremor reduction in ET. • Short pulse width DBS (spDBS) in movement disorders widens the amplitude-based therapeutic window. • SpDBS in movement disorders does not alter the therapeutic window defined by CPP. • In Parkinson's disease, spDBS seems non-inferior as to therapeutic and side effects. • In essential tremor (ET), spDBS appears superior as to therapeutic and side effects. • Future long-term studies on spDBS should address dystonia, battery longevity and ET habituation. [ABSTRACT FROM AUTHOR]

AIM: To investigate the efficacy and safety of frequency of intense pulsed light(IPL)in the treatment of meibomian gland dysfunction.METHODS: In this retrospective study, a total of 108 patients(216 eyes)with meibomian gland dysfunction admitted to our hospital from January 2021 to June 2022 were included. They were divided into two groups, with 54 cases(108 eyes)IPL group(energy density 13.0J/cm2, pulse width 6ms, delay time 50ms), and 54 cases(108 eyes)in advanced optimal pulsed technology(AOPT)group(energy density 10.0-16.0J/cm2, pulse width 7-4-4 ms in unequal-division mode). The clinical effects of the two groups were observed and compared, including ocular surface symptoms, corneal fluorescein staining score(FL), tear film lipid layer thickness(LLT), ocular surface disease index(OSDI)score, mean non-invasive tear film break-up time(NIBUTav)and first non-invasive tear film break-up time(NIBUTf), tear meniscus height, score of meibomian gland secretion and its secretion traits, and the incidence of adverse effects was also calculated.RESULTS: The effective rate of the AOPT group(106 eyes, 98.1%)was higher than that of the IPL group(90 eyes, 83.3%, P

The quality of pump pulse in few-mode-fiber Brillouin optical time domain reflectometry (FMF-BOTDR) is vital for the spontaneous Brillouin scattering of modes LP01 and LP11 because it is the comprehensive effect of the main laser linewidth and pulse width, which is firstly discussed as we know. Numerical and experimental analysis are made for the amplitude and linewidth distribution, corresponding to the signal–noise ratio (SNR) and frequency resolution in BOTDR, respectively. Simulation shows the linewidths and peak values of Brillouin scattering have the same tendency for the LP01 mode and LP11 mode when the laser linewidth is less than 1 MHz but decreases slowly until they are the same when the laser linewidth is wider than 1 MHz. With the pulse width widening, the Brillouin linewidths for LP01 and LP11 modes both decrease sharply, almost to the natural linewidth of fiber 41 MHz and 35 MHz. Experimental results show that the amplitude distribution for the LP01 mode is always larger than for the LP11 mode if the main laser has the same linewidth and the frequency fluctuation is at least 2 MHz with the fiber laser and LP11 mode. The above results could provide improved sensing resolution for FMF-BOTDR sensing system.

In this paper, the effect of various parameters on the pulse shape of the CO2 laser has been investigated. For this purpose, various parameters such as gas pressure and the length of the resonator were changed and the laser pulses shapes in each case along with their energy have been recorded. The results show that the output energy increases sharply with increasing gas pressure, so that when the pressure increases by factors of 2 and 3, the output energy increases by factors of 3 and 5 while the pulses duration reaches 0.5 and 0.3 and their buildup time reaches 0.9 and 0.7 of the initial values. In addition, by increasing the oscillator length, the width of the spike and especially of the tail parts of the pulses decease. To perform this series of experiments, a home-made laser with 1-3 atm operational pressure has been used

LiDAR has high accuracy and resolution and is widely used in various fields. In particular, phase-modulated continuous-wave (PhMCW) LiDAR has merits such as low power, high precision, and no need for laser frequency modulation. However, with decreasing signal-to-noise ratio (SNR), the noise on the signal waveform becomes so severe that the current methods to extract the time-of-flight are no longer feasible. In this paper, a novel method that uses deep neural networks to measure the pulse width is proposed. The effects of distance resolution and SNR on the performance are explored. Recognition accuracy reaches 81.4% at a 0.1 m distance resolution and the SNR is as low as 2. We simulate a scene that contains a vehicle, a tree, a house, and a background located up to 6 m away. The reconstructed point cloud has good fidelity, the object contours are clear, and the features are restored. More precisely, the three distances are 4.73 cm, 6.00 cm, and 7.19 cm, respectively, showing that the performance of the proposed method is excellent. To the best of our knowledge, this is the first work that employs a neural network to directly process LiDAR signals and to extract their time-of-flight.

In order to improve the surface quality and reduce the edge burrs, the effects of current, pulse width and pulse spacing on the machining effect of PtIr alloy WIM were studied. The results show that the machining parameters have an important effect on the surface roughness and edge burr of the material. The machining parameters of wire electrical discharge machining(WEDM) were optimized, the current was 5 A, the pulse width was 5 µs, the pulse distance was 5 µs, the machining speed was 150 steps/S, the diameter of molybdenum wire was 0.1 mm, the surface roughness Ra was 0.14 µm, and the cutting precision tolerance reached ±0.006 mm. [ABSTRACT FROM AUTHOR]

• Neurostimulation based on axon orientation, cell body proximity, and axon thickness can target therapeutic axonal pathways. • High frequency stimulation and low frequency sinusoidal waveforms may help to refine spatial targeting in Deep Brain Stimulation. • Visualizing lead placement in relation to white matter tracts using diffusion-tractography can guide waveform parameter settings. Neurostimulation has diverse clinical applications and potential as a treatment for medically refractory movement disorders, epilepsy, and other neurological disorders. However, the parameters used to program electrodes—polarity, pulse width, amplitude, and frequency—and how they are adjusted have remained largely untouched since the 1970 s. This review summarizes the state-of-the-art in Deep Brain Stimulation (DBS) and highlights the need for further research to uncover the physiological mechanisms of neurostimulation. We focus on studies that reveal the potential for clinicians to use waveform parameters to selectively stimulate neural tissue for therapeutic benefit, while avoiding activating tissue associated with adverse effects. DBS uses cathodic monophasic rectangular pulses with passive recharging in clinical practice to treat neurological conditions such as Parkinson's Disease. However, research has shown that stimulation efficiency can be improved, and side effects reduced, through modulating parameters and adding novel waveform properties. These developments can prolong implantable pulse generator lifespan, reducing costs and surgery-associated risks. Waveform parameters can stimulate neurons based on axon orientation and intrinsic structural properties, providing clinicians with more precise targeting of neural pathways. These findings could expand the spectrum of diseases treatable with neuromodulation and improve patient outcomes. [ABSTRACT FROM AUTHOR]

Insufficient corrosion resistance and conductivity are two major problems hindering the wide application of stainless steel (SS) bipolar plates in proton exchange membrane fuel cells. This study explores the use of CrN monolayer and multilayer films to improve the performance of SS304 bipolar plates, which are realized by high-power impulse magnetron sputtering with single pulse width or alternating pulse width. The effect of pulse width on the film structure and composition was characterized by various characterization techniques. Furthermore, corrosion and interfacial contact resistance (ICR) test results show that monolayer CrN film using a single long pulse of 40 μs has the lowest corrosion current density of 0.08 μA/cm2 (0.6 V vs. Ag/AgCl) and ICR of 3.15 mΩ cm2 in all coated samples. As the pulse width increases, vacancy-like defects in film decrease and the density increases, which is attribute to high bombardment flux and high average power of long pulse during deposition. • Same-phase multilayer CrN films prepared using alternating pulse width deposition. • Effect of microstructure of coated CrN film on corrosion and ICR of the SS304 BPs. • Monolayer CrN film deposited with a single long pulse has better performance. [ABSTRACT FROM AUTHOR]

The impact induced by cavitation bubble collapse can be utilized for mechanical surface treatment to improve fatigue properties of metals including additive manufactured metallic materials. A peening method using cavitation impact induced by a pulsed laser is called "laser cavitation peening (LCP)". Normally, a Q-switched Nd:YAG laser, whose pulse width is a few nanoseconds, is used for LCP, which improves the fatigue strength. The problem with LCP is that the processing time is too slow. If a laser pulse whose pulse width is a few hundred microseconds can be utilized for LCP, the repetition frequency can be increased drastically using other types of laser systems such as a fiber laser. In the present paper, in order to reveal the possibility of LCP using a pulsed laser width of a few hundred microseconds, the use of LCP with a normal-oscillation Nd:YAG laser (pulse width ≈ 200 μs) was investigated. It is demonstrated that LCP with the normal-oscillation Nd:YAG laser produced curvature in an aluminum alloy plate. The shock pressure wave and impulsive vibration of the target surface at the first collapse of laser cavitation (LC), which was induced by the normal-oscillation Nd:YAG laser, was 3–4 times larger than those of laser ablation (LA). [ABSTRACT FROM AUTHOR]

Micro-electro-mechanical system (MEMS) pressure sensors play a significant role in pulse wave acquisition. However, existing MEMS pulse pressure sensors bound with a flexible substrate by gold wire are vulnerable to crush fractures, leading to sensor failure. Additionally, establishing an effective mapping between the array sensor signal and pulse width remains a challenge. To solve the above problems, we propose a 24-channel pulse signal acquisition system based on a novel MEMS pressure sensor with a through-silicon-via (TSV) structure, which connects directly to a flexible substrate without gold wire bonding. Firstly, based on the MEMS sensor, we designed a 24-channel pressure sensor flexible array to collect the pulse waves and static pressure. Secondly, we developed a customized pulse preprocessing chip to process the signals. Finally, we built an algorithm to reconstruct the three-dimensional pulse wave from the array signal and calculate the pulse width. The experiments verify the high sensitivity and effectiveness of the sensor array. In particular, the measurement results of pulse width are highly positively correlated with those obtained via infrared images. The small-size sensor and custom-designed acquisition chip meet the needs of wearability and portability, meaning that it has significant research value and commercial prospects. [ABSTRACT FROM AUTHOR]

This work investigates the effects of different operational parameters on the pulse shape of a homemade high repetition rate (1 kHz) pulsed CO2 laser. Various parameters such as the ratio of N2 and He in the laser gas mixture and the reflectivity of the laser front mirror have changed. Then, the energy and shape of the laser pulses were recorded and analyzed. It showed that by varying the ratios of N2 and He in the laser gas mixture, the time duration of the spike and tail parts of the laser pulses can be changed in 95-140 ns and 1.5-3.5 µs range, respectively. In addition, we found that when the reflectivity of the cavity front mirror increases from 50% up to 80%, the spike duration increases from 50 ns up to 90 ns, and the tail duration decreases from 4.8 µs to 2.5 µs.

A continuous‐wave (CW) and passively Q‐switched (PQS) Yb,Ho:LuVO4 laser pumped by a 978.6‐nm laser diode (LD) is demonstrated. The maximum output power of 131 mW at 2059.78 nm in CW regime is achieved with a pump power of 3.01 W, corresponding to a slope efficiency of 10.74%. Under PQS mode operation, an average output power of 45 mW and a shortest pulse width of 100 ns were acquired by a semiconductor saturable absorber mirrors, and for all we know, this is the first report about the PQS Yb,Ho:LuVO4 laser. In addition, a maximum energy per pulse of 12.6 nJ with a pulse repetition frequency of 7.692 MHz was obtained, corresponding to a peak power of 58.5 mW. The beam quality factor was measured to be Mx2 $\,{{\boldsymbol{M}}}_{{\boldsymbol{x}}}^{{\boldsymbol{2}}}$ = 1.10 and My2 ${{\boldsymbol{M}}}_{{\boldsymbol{y}}}^{{\boldsymbol{2}}}$ = 1.10 from the PQS Yb,Ho:LuVO4 laser. [ABSTRACT FROM AUTHOR]

As the hardware performance of laser and other infrastructures is restricted, how to effectively improve the intensity of the residual compressive stress field introduced by laser shocks has become the focus of researchers. With the help of the ABAQUS software of finite element simulation and the determined target material of 304-type steel, the rules of pulse width and laser energy regulating the distribution of the residual stress field were intuitively confirmed. The results show that different parameters of the pulsed laser led to different degrees of influence on the main characteristics of the residual stress field, and these influence laws can be effectively used to propose a composite technology with varied parameter characteristics. By comparing and analyzing the control effects of the residual stress field of different composite processes, the feasibility and effectiveness in improving the intensity of the residual compressive stress field were verified. The processing method of gradually changing pulse laser parameters described in this paper is expected to achieve the goal of high-intensity surface strengthening more economically. [ABSTRACT FROM AUTHOR]

Introduction/Background: The pulse width (PW) parameter in sacral neuromodulation (SNM) is understudied, with no evidence‐based guidance available on optimal PW for urinary indications. The aim of this prospective, randomized, single‐blinded, 3 × 3 cross over design study was to estimate the effect of two PW settings (60 µs, 420 µs) compared to the industry standard (210 µs) on SNM efficacy, quality of life, and device parameters in patients who were stable and satisfied with their SNM treatment. Methods/Materials: Eligible patients were previously implanted and had urge incontinence or urgency‐frequency with satisfaction on SNM at time of enrollment. Patients completed a 3‐day voiding diary, validated questionnaires, and device interrogations with sensory threshold assessment at baseline and after a 4‐week period on each of the three PW settings, to which they were randomized. Eighteen participants completed the study, as called for by power analysis. Results: Eighteen patients were enrolled in the study. Mean age was 68 years and implant duration at the time of participation was 4.4 years. While PW variations did not produce significant differences in overall objective outcomes, device parameters, including sensory threshold amplitude and battery life differed significantly. Shortened PW necessitated higher amplitude while conserving battery life. Stimulus sensation location, quality, and intensity did not differ between PW. Standard PW was chosen by 11 patients after the study, 5 chose extended, and 2 chose shortened. Those who chose alternative PW achieved significant reductions in urinary frequency from enrollment −2.23 voids/day (p = 0.015). Upon sub‐analysis, patients reporting "much better" or "very much better" on extended PW achieved significant reductions in urinary frequency and nocturia at 5.6 and 0.4, compared to 8.5 and 2.16 at baseline (p = 0.005, p = <0.001). Whereas those reporting "much better" or "very much better" on shortened PW achieved significant reductions in urinary frequency at 5.15 compared to 7.35 (p = 0.026). There were no adverse events or complications. Conclusions: Overall SNM effectiveness was unchanged with alternative PW; however, 39% of patients preferred alternative to standard PW and achieved significant improvements in urinary symptoms with such. Shorter PW can also provide savings in estimated battery life without sacrificing therapeutic efficacy. [ABSTRACT FROM AUTHOR]

This paper deals with pulsed mode laser beam welding (LBW) on 2 mm thick Ti-6Al-4V alloy sheets. ANSYS Fluent 16.0 version is utilized to develop a generic model with Vc++ code. The model is validated with test results. The optimal LBW parameters are obtained by maximizing the depth of penetration (DP) and minimizing the weld bead width (BW). To minimise the number of numerical simulations, Taguchi approach is adopted. The LBW parameters considered are pulse frequency, pulse width and welding speed, the absorbed power is kept as constant. The performance indicators are width of fusion zone, depth of penetration, heat affected zone and maximum temperature. The optimal LBW parameters are found to be dependent on the process indicators. A simple reliable modified Taguchi approach is followed to get a set of optimal LBW parameters for maximum DP and minimum BW.

A full understanding of the impact of charge trapping on the memory window (MW) of HfO2-based ferroelectric field effect transistors (FeFETs) will permit the design of program and erase protocols, which will guide the application of these devices and maximize their useful life. The effects of charge trapping have been studied by changing the parameters of the applied program and erase pulses in a test sequence. With increasing the pulse amplitude and pulse width, the MW increases first and then decreases, a result attributed to the competition between charge trapping (CT) and ferroelectric switching (FS). This interaction between CT and FS is analyzed in detail using a single-pulse technique. In addition, the experimental data show that the conductance modulation characteristics are affected by the CT in the analog synaptic behavior of the FeFET. Finally, a theoretical investigation is performed in Sentaurus TCAD, providing a plausible explanation of the CT effect on the memory characteristics of the FeFET. This work is helpful to the study of the endurance fatigue process caused by the CT effect and to optimizing the analog synaptic behavior of the FeFET. [ABSTRACT FROM AUTHOR]

In this paper, the output electrical pulse width of semi-insulating gallium arsenide photoconductive semiconductor switch (SI-GaAs PCSS) is controlled by means of Blumlein pulse formation line. Under the condition that the bias voltage is 28 kV and the laser pulse width is 9.5 ns, the electric pulse width obtained by using high-power pulse system transmission is 10 ns and the output voltage is 23 kV. Based on the Blumlein pulse formation line theory, the output pulse width and transient impedance are analyzed. The results show that the holding time of carriers avalanche multiplication can be controlled. [ABSTRACT FROM AUTHOR]

Germanium-tin (GeSn) alloy is considered a promising candidate for a Si-based short-wavelength infrared range (SWIR) detector and laser source due to its excellent carrier mobility and bandgap tunability. Pulsed laser annealing (PLA) is one of the preeminent methods for preparing GeSn crystal films with high Sn content. However, current reports have not systematically investigated the effect of different pulse-width lasers on the crystalline quality of GeSn films. In addition, the intensity of the spot follows the gaussian distribution. As a result, various regions would have different crystalline properties. Therefore, in this study, we first provide the Raman spectra of several feature regions in the ablation state for single spot processing with various pulse-width lasers (continuous-wave, nanosecond, femtosecond). Furthermore, the impact of laser pulse width on the crystallization characteristics of GeSn film is explored for different single-spot processing states, particularly the Sn content incorporated into GeSn crystals. The transient heating time of the film surface and the faster non-equilibrium transition of the surface temperature inhibit the segregation of the Sn component. By comparing the Raman spectra of the pulsed laser, the continuous-wave laser shows the most acute Sn segregation phenomenon, with the lowest Sn content of approximately 2%. However, the femtosecond laser both ensures crystallization of the film and effective suppression of Sn expulsion from the lattices, and the content of Sn is 8.07%, which is similar to the origin of GeSn film. [ABSTRACT FROM AUTHOR]

Laser ablation of semiconductor silicon has been extensively studied in the past few decades. In the ultrashort pulse domain, whether in the fs scale or ps scale, the pulse energy fluence threshold in the ablation of silicon is strongly dependent on the pulse width. However, in the ns pulse scale, the energy fluence threshold dependence on the pulse width is not well understood. This study elucidates the interaction energy dependency on pulse width in ns NIR laser ablation of silicon. The level of ablation or melting was determined by the pulse energy deposition rate, which was proportional to laser peak power. Shorter pulse widths with high peak power were likely to induce surface ablation, while longer pulse widths were likely to induce surface melting. The ablation threshold increased from 5.63 to 24.84 J/cm2 as the pulse width increased from 26 to 500 ns. The melting threshold increased from 3.33 to 5.76 J/cm2 as the pulse width increased from 26 to 200 ns, and then remained constant until 500 ns, the longest width investigated. Distinct from a shorter pulse width, a longer pulse width did not require a higher power level for inducing surface melting, as surface melting can be induced at a lower power with the longer heating time of a longer pulse width. The line width from surface melting was less than the focused spot size; the line appeared either as a continuous line at slow scanning speed or as isolated dots at high scanning speed. In contrast, the line width from ablation significantly exceeded the focused spot size. [ABSTRACT FROM AUTHOR]

Working conditions often do not meet the regulatory requirements for hygienic indicators, specifically, there are violations regarding the presence of harmful impurities in the air of the working area. In such cases, motorized filter respirators are used to protect respiratory organs, which require the development of a suitable system for managing operational indicators for effective operation. The purpose of this study was to improve the control system of a motorized filter respirator to increase protective efficiency. To create a suitable control system, a structural-parametric synthesis of performance indicators' management was applied, based on the relationships between the main variables (outgoing regulated variables, controlling influences and disturbances). A new working scheme of the control object with selected design elements of the blower was developed, the main difference of which is the use of the Arduino Uno R3 board, the LCD Keypad Shield module with a two-line display for controlling the airflow modes, according to the change in the resistance of the filter considering the accumulation of dust sediment assuming that the transfer function can be represented by an aperiodic link of the 1st order with sufficient accuracy for practice. To work out the operating modes and determine the duration of the protective effect, a software model of the operation of the motorized filter respirator was created, which helped evaluate the influence of the dust concentration on the change in airflow through the filter elements, considering the accumulation of dust sediment on the protective effectiveness. Recommendations were developed to ensure the effective functioning of the protective device pursuant to the requirements under the most adverse conditions. The practical significance of this study is that thanks to the improvement of the control system of the motorized filter respirator, more comfortable and effective protection is provided, specifically in conditions of severe or hazardous working environments. [ABSTRACT FROM AUTHOR]

The effects of electrical pulse width and output irradiance on the inactivation effect of intense pulse light (IPL) are studied in this paper. The measured radiant efficiency of pulsed xenon lamp can be more than 50%, and its irradiance can reach levels 100-times greater than that of a low-pressure mercury lamp. Staphylococcus aureus is used in inactivation experiments. When the irradiance and dose are both constant, there is no significant difference in inactivation efficiency when the pulse width is changed. However, a narrow pulse width corresponding to high irradiance at the same single-pulsed dose displays better inactivation effect. Experimental results are compared between the xenon lamp and low-pressure mercury lamp. The reduction factor (RF) value of the xenon lamp is more than 1.0 higher under the condition of both the same dose and irradiance. In order to achieve the same RF value, the dose of continuous-wave light must be at least three-times greater than that of pulsed light. The spectral action of the pulsed light is also studied. It is confirmed that UVC plays a major role across the whole spectrum. The experimental results show that extreme high-pulsed irradiance presents the main contributing factor behind the excellent bactericidal effect of IPL. [ABSTRACT FROM AUTHOR]

Laser shock peening (LSP) process parameters have an important influence on the strengthening effect. In this study, theoretical calculations were used to determine a suitable range of stress wave peaks (5.09 GPa–6.36 GPa) for laser shocking, which consider the material properties of alloy steel 40Cr. In addition to theoretical calculations, the finite element numerical simulation of a single-point laser shock was also performed. The residual stresses of specimens under different shock pressure waves were simulated, and then the optimal pulse width was determined as 20 ns and the optimal pulse energy was determined as 10 J. Finally, the influences of different pulse energies on the microhardness, residual stress, microstructure, and shock-affected layer thickness of metallic materials were comprehensively investigated through experiments, and the optimization of the laser shock energy was proved to be 10 J. An optimized combination of parameters of a single-point laser shock for 40Cr was obtained, in which the spot diameter was 3 mm, the pulse width was 20 ns, and the pulse energy was 10 J. The study has implications for the selection of LSP process parameters for alloy steels. [ABSTRACT FROM AUTHOR]

Single-event transient (SET) due to heavy-ion strike is a serious reliability concern for devices operated in radiation environment. Due to technology scaling, nodal capacitance decreases which increases the SET vulnerability. In this paper, the sensitivity of SET pulse width in 45nm bulk and SOI MOSFET to linear energy transfer (LET), heavy-ion track length, angle of strike, characteristic radius, and characteristic time of the track is analysed. The modification of SET pulse width while propagating through 45nm bulk-and SOI-based CMOS chain of inverters and its dependence on aforementioned radiation parameters is also analysed. The results show that all the pulses produced in SOI-based inverter chain get attenuated during propagation and do not reach the last stage. However, in the case of bulk, any SET having pulse width greater than 37 ps (measured using full width at half maximum) propagates and reaches the last stage of the inverter chain. Thus, the SOI devices are more immune to SET compared to the bulk, for different heavy-ion track parameters. [ABSTRACT FROM AUTHOR]

Electrophysiological stimulation has been widely adopted for clinical diagnostic and therapeutic treatments for modulation of neuronal activity. Safety is a primary concern in an interventional design leveraging the effects of electrical charge injection into tissue in the proximity of target neurons. While modalities of tissue damage during stimulation have been extensively investigated for specific electrode geometries and stimulation paradigms, a comprehensive model that can predict the electrochemical safety limits in vivo doesn’t yet exist. Here we develop a model that accounts for the electrode geometry, inter-electrode separation, material, and stimulation paradigm in predicting safe current injection limits. We performed a parametric investigation of the stimulation limits in both benchtop and in vivo setups for flexible microelectrode arrays with low impedance, high geometric surface area platinum nanorods and PEDOT:PSS, and higher impedance, planar platinum contacts. We benchmark our findings against standard clinical electrocorticography and depth electrodes. Using four, three and two contact electrochemical impedance measurements and comprehensive circuit models derived from these measurements, we developed a more accurate, clinically relevant and predictive model for the electrochemical interface potential. For each electrode configuration, we experimentally determined the geometric correction factors that dictate geometry-enforced current spreading effects. We also determined the electrolysis window from cyclic-voltammetry measurements which allowed us to calculate stimulation current safety limits from voltage transient measurements. From parametric benchtop electrochemical measurements and analyses for different electrode types, we created a predictive equation for the cathodal excitation measured at the electrode interface as a function of the electrode dimensions, geometric factor, material and stimulation paradigm. We validated the accuracy of our equation in vivo and compared the experimentally determined safety limits to clinically used stimulation protocols. Our new model overcomes the design limitations of Shannon’s equation and applies to macro- and micro-electrodes at different density or separation of contacts, captures the breakdown of charge-density based approaches at long stimulation pulse widths, and invokes appropriate power exponents to current, pulse width, and material/electrode-dependent impedance. [ABSTRACT FROM AUTHOR]