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The structural characteristics of loose zinc deposits obtained in pulse-potential modes are calculated using a phenomenological model. Increasing the duty cycle leads to intensified anodic dissolution during pauses and obtaining of denser deposits, due to the formation of dendrites with fewer tips, yet, a larger diameter as compared to the deposits obtained in the potentiostatic mode. The linear dependence of the diameter of the tips of dendrites forming a loose zinc deposit on the duty cycle is found. There is a critical time corresponding to the achievement of zero deposit growth rate when the metal deposited during the pulse will completely dissolve during the pause. [ABSTRACT FROM AUTHOR]

The present paper deals with hydrogen generation using sono-electrolysis. The experimental investigation is based on a parametric study of water electrolysis system according to the nature of the dissolved salt KOH/NaOH, the concentration of salt in the electrolyte, the temperatures of the electrolyte and the bath (27, 40, 45, 50, 55 and 60 °C), and the nature of the electrode (stainless steel 304, nickel, nickel foam and graphite). Two electrolyzer designs were adopted, namely Hoffmann cell and H-cell. The parametric study revealed the optimum configuration under silent conditions, before integrating the ultrasound power both in continuous and pulsed modes, in order to assess its effect on the energy efficiency of the process and the kinetics of hydrogen production. Under optimal conditions of electrolyte and electrode material, i.e., in KOH electrolyte using nickel foam electrodes, the integration of continuous ultrasound resulted in an increase of 7.78% in the cell current under ambient temperature, corresponding to 64% reduction in the bubble resistance. With the same configuration, the effect of sonication was negligible at the optimal solution temperature of 45 °C, while room temperature operation of the sono-electrolyzer conducted to a better performance than under silent conditions. Finally, continuous sonication mode led to the most performant operation with all the studied configurations, both kinetically and energetically, as compared to pulsed mode. • The geometry of the electrolytic cell controls the ionic transport between both anodic and cathodic compartments. • The effect of the electrolyte in sono-electrolysis is related to surface tension and ionic conductivity. • Heterogeneous solid liquid acoustic cavitation controls the kinetics of H 2 production by sono-electrolysis using nickel foam. • Continuous sono-electrolysis using KOH and nickel foam leads to 64% reductio of the bubble resistance. • Continuous sonication is the optimal mode in sono-electrolysis, both kinetically and energetically. [ABSTRACT FROM AUTHOR]

A phenomenological model describing the change in the structural characteristics of loose zinc deposits obtained in pulsed current modes is presented. Comparison of experimental data on the structural properties of deposits with the results of model calculations indicates the adequacy of the model. To describe the features of the dendritic deposit growth and to determine the duration of the homogeneous structure formation in pulsed modes, the concept of critical thickness is introduced, at which a sharp change in the loose deposit density occurs. The dependence of the zinc deposit critical thickness on the pulse duty ratio under pulsed current modes is determined. The increasing of the pulse duty ratio leads to denser deposits with rounded dendrite shapes and fewer growth points, as compared with the deposit obtained in galvanostatic mode. [ABSTRACT FROM AUTHOR]

An approach is developed to study temporal behavior of the active region overheating in high-power semiconductor lasers (λ = 1060 nm) with an ultrawide aperture (800 μm) operating in a quasi-continuous regime of pumping by current pulses with an amplitude of 21 A, a duration of 1 ms, and a repetition rate of 10 Hz. The approach is based on measuring the lasing dynamics with spectral selection. The lasing spectrum analysis shows that the region of the rising edge, where the amplitude of the current pulse increases, is characterized by a maximum red-shift rate of 30 nm ms–1, which is due to both thermal and nonthermal effects. The pulse region corresponding to a constant pump current amplitude is characterized only by a thermal red shift of the lasing spectrum long-wavelength edge at a rate of ~1 nm ms–1. The obtained experimental active region overheating is 2.78°C for the constant pump current amplitude range, which agrees with the calculated overheating of 3.08°C for the pump conditions under study. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to compare the effectiveness of pulsed and continuous modes of therapeutic ultrasound (US) for phonophoresis in the treatment of subacromial impingement syndrome (SAIS). Patients and methods: Between April 2019 and January 2021, a total of 66 patients with SAIS (17 males, 49 females; mean age: 48.2±8.6 years; range, 19 to 64 years) were included. The patients were randomized to the phonophoresis with continuous mode group (n=22), phonophoresis with pulsed mode group (n=22), and phonophoresis with sham US group (n=22). Five grams of ibuprofen phonophoresis was applied in five sessions per week for three weeks for all groups. Primary outcomes were pain intensity as assessed by the Visual Analog Scale (VAS) and shoulder functions by the short version of Disabilities of the Arm, Shoulder and Hand Questionnaire (QuickDASH). The secondary outcome was the quality of life as assessed by the Nottingham Health Profile (NHP). All patients were evaluated at pre-treatment, post-treatment, and at three months after the end of the treatment. Results: There was a significant improvement in pain during activity, shoulder function, and quality of life after treatment in phonophoresis with continuous and pulsed modes compared to phonophoresis with sham US (p<0.05). Phonophoresis with continuous mode was superior to other groups in reducing pain at rest (p<0.05). Changes between pre-treatment and the three-month follow-up showed a significant improvement in pain during activity and shoulder functions in phonophoresis with continuous and pulsed modes, compared to phonophoresis with sham US (p<0.05). Phonophoresis with pulsed mode was more effective than the other interventions in improving quality of life during the same period (p<0.05). Conclusion: Despite a significant change in phonophoresis with continuous and pulsed modes, it is more pronounced for rest pain in the early period in continuous mode and for quality of life during follow-up in pulsed mode. [ABSTRACT FROM AUTHOR]

The properties of synthesized nanostructured materials are determined by the methods of their preparation. The combination of electric discharges with liquid is a new tool for the synthesis of pure structures but the conditions for obtaining structures play an important role as in the case of traditional synthesis methods. In this work, the electrical and emission characteristics of a low-temperature direct-current plasma in contact with water at currents of 0.25 and 0.80 A are studied. The values of the power (energy) of single discharges are calculated. It is established that this type of discharge burns in the pulsed mode. The value of the discharge current affects the frequency of occurrence of discharges and the energy of a single discharge. It is shown that low-temperature underwater plasma is an effective tool for the synthesis of nanocomposites based on metal oxides, the precursors of which are metal electrodes. The emission spectroscopy method is used to study the emission spectra of underwater plasma. The sputtering of electrodes during plasma combustion is established. X-ray phase analysis shows that the phase composition of the resulting products is determined by the strength of the plasma current. The formation of oxides and hydroxides of Ni and Cr with different valences of metal ions is found. [ABSTRACT FROM AUTHOR]

The elements of repair technology of electron beam welding in the manufacture of a metal-ceramic cathode unit of a powerful welding electron beam gun are considered. A low degree of heat generation at the place of weld overlapping inherent in electron beam welding reduces the risk of buckling parts being joined and provides the maximum compliance with the required sizes of the unit. The need in repair of the cathode unit was determined by the cases of supplying imported insulators with defects in the form of deviations of a thickness from 0.5 to 1.0 mm in the wall of the metal flange («collar») in the brazed joint with the insulator. It was necessary to eliminate the consequences of a violation of the mechanical treatment of the insulator collar after brazing. The possible ways and schemes of repair technologies of such units are shown that allow avoiding the rejection of valuable parts and transferring them to the category of those subjected to restoration. The presented repair technologies involve the use of circumferential insertsbandages of different configuration for two variants to eliminate welding defects associated both with local repair of the edge as well as with repair of its quite elongated areas. Due to a correct choice of the shape of repair inserts, the use of some technological methods and observance of the accuracy of assembly and the sequence of repair welding, it became possible to preserve geometric dimensions and to ensure the functionality of the welded assembly as a whole. 6 Ref., 6 Tabl., 6 Fig. [ABSTRACT FROM AUTHOR]

The elements of repair technology of electron beam welding in the manufacture of a metal-ceramic cathode unit of a powerful welding electron beam gun are considered. A low degree of heat generation at the place of weld overlapping inherent in electron beam welding reduces the risk of buckling parts being joined and provides the maximum compliance with the required sizes of the unit. The need in repair of the cathode unit was determined by the cases of supplying imported insulators with defects in the form of deviations of a thickness from 0.5 to 1.0 mm in the wall of the metal flange ("collar") in the brazed joint with the insulator. It was necessary to eliminate the consequences of a violation of the mechanical treatment of the insulator collar after brazing. The possible ways and schemes of repair technologies of such units are shown that allow avoiding the rejection of valuable parts and transferring them to the category of those subjected to restoration. The presented repair technologies involve the use of circumferential inserts-bandages of different configuration for two variants to eliminate welding defects associated both with local repair of the edge as well as with repair of its quite elongated areas. Due to a correct choice of the shape of repair inserts, the use of some technological methods and observance of the accuracy of assembly and the sequence of repair welding, it became possible to preserve geometric dimensions and to ensure the functionality of the welded assembly as a whole. [ABSTRACT FROM AUTHOR]

Copyright of Vatten is the property of Foreningen Vatten and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The initial phases of penetration of cold waters from the sea surface into the depth are analyzed within a study of the process of sea surface cooling. The phases of immersion of small volumes of water with negative buoyancy, reaching the bottom, and propagation along the bottom slope have been studied in laboratory experiment and numerical simulation. The interaction between two small volumes of salt water, which sequentially originate in the surface freshwater layer, during their immersion and subsequent propagation along the bottom slope is described in detail. Laboratory experiments have shown that the second of two water spots, equal in volumes and negative buoyancy, always reaches the first one during propagation along the bottom slope. A phenomenological explanation of this fact is suggested. The images of individual phases of the water-spot propagation show quite long-term stability of laminar structure of tracers inside the water spots. The simulation allows distinguishing two characteristic phases (advective and viscous) of interaction between two water spots. The experimental and simulation results allow us to suggest the general scheme of the negative-buoyancy water dynamics in coastal waters. [ABSTRACT FROM AUTHOR]

In this work, the influence of some types of the pulsed deposition mode of electrochromic films from aqueous solutions of nickel nitrate with the addition of polyvinyl alcohol was investigated. Glass coated with a fluorine-doped tin oxide film was used as the basis for deposition. The deposition of nickel (II) hydroxide – polyvinyl alcohol electrochromic films was carried out in three pulsed modes: –0.2 mA/cm²×5 s, 0 mA cm²×5 s (10 minutes); –0.5 mA/cm²×2 s, 0 mA/cm²×8 s (10 minutes); –1 mA/cm²×1 s, 0 mA/cm²×9 s. In this case, the amount of electricity used for the formation of thin-film electrodes was the same for all samples. The resulting films showed dramatic differences in electrochemical, optical, and quality characteristics. The sample obtained in the mode of the highest cathode current density and the duration of the no-current condition (1 mA/cm²×1 s, 0 mA/cm²×9 s) had the worst specific capacity and optical characteristics. This sample was characterized by the highest number of coating defects and color non-uniformity as well. The sample, which was obtained at average current densities (–0.5 mA/cm²×2 s, 0 mA/cm²×8 s), had the highest specific characteristics among the electrodes in the series. The coating was uniform and solid. Also, this sample had the greatest stability of the coloration depth value, which varied from 79.1 to 78.1 % (first to fifth cycles). The sample obtained in the mode –0.2 mA/cm²×5 s, 0 mA/cm²×5 s showed moderate specific indicators, however, there were some coating defects. According to the results obtained, a mechanism was proposed that explained the differences in the characteristics of thin-film electrodes formed in different modes. This mechanism consists of changing the time of non-stationary processes and the distribution of the current density with a change in the value of the deposition current density, the duration of the cathode period, and the no-current condition. [ABSTRACT FROM AUTHOR]

In this study, a pulsed mode ultrasound assisted extraction was performed for the extraction of bioactive compounds from Pomegranate (Punica granatum L.) peel. Box-Behnken experimental design combined with response surface methodology, was applied for the optimization of process conditions. The independent variables investigated were ultrasound amplitude (50–80%), sonication time (5–15 min), duty cycle (0.2–0.8), and methanol concentration (30–70%) to maximize the yield of total phenolic content, flavonoid content, total condensed and hydrolysable tannin (TCT and THT respectively), and antioxidant activity (DPPH and FRAP). The experimental results were fitted to quadratic models, and statistical analysis in terms of multiple regression, and analysis of variation was carried out for each response variable. The optimum predicted values of the response variables were obtained at 70% methanol concentration, 12.8 min of sonication treatment at a duty cycle of 0.58, and 80% ultrasound amplitude. A comparative analysis at optimized condition showed better recovery of bioactive compounds in pulsed mode, compared to continuous mode of sonication. Correlation analysis of the response variables was done to find the associations among the variables. Multivariate analysis using principal component analysis, and hierarchical cluster analysis was done for better understanding of interactions among experimental treatments and responses. [ABSTRACT FROM AUTHOR]

The basis of modern radar techniques is the direct use of radio-physical data on the power of backscattering. At the same time, the data volume received from the radar allows us to form new estimates and essentially specify classical ones. Significant steps have been made in this direction, using, for example, phase (Doppler) methods. The "modified Rayleigh model" used in radar meteorology to form a scattered field on rarefied medium particles is called the Kerr-Rice model. The main advantage of the Rayleigh model is its simplicity. But it itself contains a deep contradiction, consisting in its logical completion. Based on the statistics study of the first distribution in the rains of varying intensity the authors on a large statistical material have determined the fact of their not Rayleigh form and extreme stability of the latter in relation to natural changes of precipitation intensity. The first distribution is different from the theoretically expected one in the Kerr-Rice model, which makes it possible to use linear-logarithmic detection. It is concluded that the width and the mean of the spectrum of the same signal have the expected dynamics with respect to changes in precipitation intensity and dynamic processes in them. Tables with experimental data are presented. Two main distribution models are considered: lognormal and "logo-gamma-functional". It is concluded that, despite the absence of qualitative differences, the difference in the form of the distributions obtained with different equipment can be a natural consequence of significant discrepancies in the peak power and / or the width of the antenna pattern. The graphs of the first experimental distributions of envelope fluctuations on a linear and semi-logarithmic scale are presented.

Resistive oscillations of axial plasma with ionization effects are analyzed in configuration similar to the Hall effect thrusters. From analysis of stationary equations we have identified different types of the steady-state plasma flow profiles and use these solutions as initial conditions in time-dependent initial value simulations. We have identified unstable regimes with intrinsic oscillations, as well as stable regions without oscillations. It was found that nonlinear oscillations may exist in different form depending on the range of plasma parameters. Single mode coherent, multi-mode with nonlinear harmonics, and incoherent (stochastic) mode regimes were identified. We have further investigated the role of boundary conditions on the characteristics of nonlinear oscillations. [ABSTRACT FROM AUTHOR]

The efficiency of using electron beam welding in producing dissimilar joints of structural materials of all thicknesses and shapes is well-known. The work for the first time considers the possibility of using electron beam welding for the production of high-precision parts of optical system in cathode unit, providing the necessary parameters and their joining with electron beam gun insulator in future. The use of electron beam welding at the final stage of manufacturing cathode unit opens the opportunity of minimizing the number of further technological operations. It is noted that to create the welding technology, in which the operation of welding would become a final assembly operation, the development of new designs of welded joints and schemes for assembly of cathode unit are required. Due to a correct design of welding units and compliance with the accuracy of assembling for welding, it became possible to preserve geometric dimensions after electron beam welding and to provide the operational reliability of the design as a whole. [ABSTRACT FROM AUTHOR]

The efficiency of using electron beam welding in producing permanent joints of structural materials of all thicknesses and shapes is well-known. The work for the first time considers the possibility of using electron beam welding for the production of high-precision parts of optical system in cathode unit, providing the necessary parameters and their joining with electron beam gun insulator in future. The use of electron beam welding at the final stage of manufacturing cathode unit opens the opportunity of minimizing the number of further technological operations. It is noted that to create the welding technology, in which the operation of welding would become a final assembly operation, the development of new designs of welded joints and schemes for assembly of cathode unit are required. Due to a correct design of welding units and compliance with the accuracy of assembling for welding, it became possible to preserve geometric dimensions after electron beam welding and to provide the operational reliability of the design as a whole. 5 Ref., 6 Figures. [ABSTRACT FROM AUTHOR]

Robust electrolyte-gated organic field-effect-transistors (OFETs) are particularly needed for the development of biosensing devices. However, when a FET biosensor operates in aqueous environments or even in real biological fluids, some critical issues may arise due to the possible lack of environmental long-term and/or operational stability. An important source of instability is associated with the degradation of the organic electronic channel materials such as for instance, poly-3-hexylthiophene (P3HT), a benchmark commercially available p-type organic semiconductor. In this work, the investigation of critical parameters, such as the control over spurious electrochemical phenomena as well as the operating conditions that can affect water-gated OFETs lifetime, is reported, together with a proposed modeling of the P3HT stability curve over 1 week in water. The investigation of possible morphological/chemical modifications occurring at the polymer surface after operating in water for 2 weeks was carried out. Moreover, it is proven how the addition of a gel layer can extend the P3HT based water-gated OFET shelf life up to 2 months.

It is shown that the parameters of pulsed potential modes (pulse-on and pulse-off times) have a pronounced effect on the growth dynamics and properties of loose metal deposits in the cases that the process proceeds under the conditions of non-steady-state diffusion. It is proposed to use a ratio between the cathodic and anodic charges in a cycle as a parameter that characterizes the concentration changes. By varying the parameters of pulsed potential, zinc deposits of various morphology can be obtained: from compact deposits to highly porous deposits that consist of branched dendritic particles. [ABSTRACT FROM AUTHOR]

A piezoelectric transducer in the form of a damped plate radiating into steel through a system of transition layers is considered. The algorithm for calculating the frequency response of the transducer is described, and its pulsed operation mode is investigated. A voltage pulse in the form of a half sine wave at the plate’s antiresonance frequency is selected as an electrical excitation signal. Some materials used for manufacturing certain transducer design elements are considered. Based on estimative calculations of the geometrical thicknesses of layers actually encountered in the practice of ultrasonic testing, their wave thicknesses are chosen. The data obtained is used to determine the shape of the emitter output signal. Calculations are carried out in a wide range of specific acoustic impedances of the wear plate. [ABSTRACT FROM AUTHOR]

The influence of electron-beam parameters on the thickness and phase composition of a hardened layer formed upon the nitriding of austenitic stainless steel 12Cr18Ni10Ti in plasma produced by a beam in a low-pressure (3 Pa) nitrogen--argon mixture is studied. The results obtained in the DC and pulse-periodic modes of beam generation with the same mean current and electron energy are compared. In this case the negative bias voltage applied to the samples is 100 V. The nitriding temperature of 400°C is maintained at a mean beam current of 2.6 A and various combinations of frequency (100--500 Hz) and current pulse durations (0.1-0.3 ms) with an amplitude of 80 A. The mean ion-plasma current densities in the DC and pulsed modes are close in magnitude (2-3 mA/cm² at 400°C). The high pulsed ion-current density (35-70 mA/cm²) creates conditions under which the surface sputtering rate during the pulse exceeds the growth rate of the nitrided layer. The nitriding of steel in the pulsed and DC modes over four hours gives the same result. Hardened layers with a thickness of 7-8 µm and a microhardness of the surface component of 15 ± 1 GPa in which the main phase is a supersaturated nitrogen solid solution (expanded austenite) are formed. A possible explanation is that nitriding in an electron-beam plasma proceeds mainly under the action of long-lived active neutral nitrogen particles rather than as a result of ion bombardment. [ABSTRACT FROM AUTHOR]

Thermal effect of dual wavelength (980 and 1064 nm) laser application in skin incision closure was assessed on 18 male and female Wister rats. 1-cm-long incisions were made on the shaved dorsal region of 220–250 g animals. The incisions were closed by laser irradiation at 1 W and exposure time, 5 seconds in continuous-wave mode (CW) and 1 W and exposure time, 10 seconds in pulsed mode to deliver total energies of 5 J and 10 J per spot onto the incisions, respectively. Animals from each group were sacrificed at 0th, 4th, and 7th days and the skin samples of the weld area were excised for histological analysis using Hematoxylin and Eosin (H & E) stain. Mean thermally altered area (TAA) of CW-mode laser-treated groups was found to increase significantly (p< 0.05) compared with pulsed mode laser treated group at 0th and 4th days post-irradiation while no significant difference (p> 0.05) was statistically found at 7th day post-irradiation. Moreover, tighter closure was observed with CW group at 7th day post-irradiation. We thus conclude that 1 W, 5 J for 5 seconds CW mode laser application of 980 and 1064 nm combined beam form in skin incision closure was found to have absolute wound healing capability with minimal thermal alteration.ABSTRACT FROM PUBLISHERCopyright of Journal of Cosmetic & Laser Therapy is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. [ABSTRACT FROM AUTHOR]

Indium arsenide (InAs)‐based quantum cascade lasers (QCLs) operating close to 25 µm are reported. Thick n‐doped InAs cladding layers were used for optical confinement. Fabry–Perot lasers exhibited a threshold current density as low as 1.1 kA/cm2 in pulsed mode at 80 K. The lasers operated in this regime up to 240 K, where the threshold current density increased up to 1.7 kA/cm2. These are the lowest threshold current densities for QCLs operating above 20 µm. [ABSTRACT FROM AUTHOR]

Recent development of water-jet assisted underwater laser cutting has shown some advantages over the gas assisted underwater laser cutting, as it produces much less turbulence, gas bubble and aerosols, resulting in a more gentle process. However, this process has relatively low efficiency due to different losses in water. Scattering is reported to be a dominant loss mechanism, which depends on the growth of vapor layer at cut front and its removal by water-jet. Present study reports improvement in process efficiency by reducing the scattering loss using modulated laser power. Judicious control of laser pulse on- and off-time could improve process efficiency through restricting the vapor growth and its effective removal by water-jet within the laser on- and off-time, respectively. Effects of average laser power, duty cycle and modulation frequency on specific energy are studied to get an operating zone for maximum efficiency. Next, the variation in laser cut quality with different process parameters are studied within this operating zone using Design of experiment (DOE). Response surface methodology (RSM) is used by implementing three level Box-Behnken design to optimize the variation in cut quality, and to find out the optimal process parameters for desired quality. Various phenomena and material removal mechanism involved in this process are also discussed. [ABSTRACT FROM AUTHOR]

Reasons for the appearance of 'precursors' and 'tails' in the analysis of pulsed operation mode of acoustic transducers by the method of integral transformations are considered. It is emphasized that the reason is the impossibility to make an accurate allowance for the actual dependence of the complex wave number on frequency over the entire frequency range. [ABSTRACT FROM AUTHOR]

The results of a review of literature data show that electric arc metallizing systems are characterized by high consumption of compressed air. Spraying is accompanied by the high-intensity interaction of the spraying air jet with the liquid metal of the molten ends of the electrodes, leading to rapid burnout of the alloying elements. The intensity of the oxidation reaction depends on the heat resistance of the sprayed material, the dispersion of the particles, the affinity of the components for oxygen and the technological parameters of the coatings. In order to reduce the oxidation effect, it is proposed to use a pulsed air-spraying jet. To solve this problem, experiments were carried out to develop appropriate equipment for the EN-17 stationary electric arc metallizing system characterized by the pulsed discharge of the air-spraying jet in the range 0–130 Hz. The experimental results show that the spraying jet is pulsed with temporary breaks. When using circular cross sections, the pulse smoothly becomes larger. The application of the right-angled section results in the pulse shape increasing at a higher rate. The experimental results show that the oxidation effect of the air-spraying jet is reduced. It is also shown that the optimum frequency resulting in improved properties of the coating is in the range 40–80 Hz. [ABSTRACT FROM PUBLISHER]

Electron Spin Resonance investigations allow to attribute a broad absorption band below the band-to-band transition of ZnO:Co to photoionization transitions of Co-ions. This absorption, with the onset at about 2.4-2.6 eV, is due to cobalt recharging, as concluded from the photo-ESR and pulsed ESR experiments. In these experiments light sensitive ESR signals of Co2+ and shallow donor are observed. Their response to light favors cobalt 2+ to 3+ photoionization. [ABSTRACT FROM AUTHOR]

The paper presents the results of investigation of pulse atomizing air jet application in electric arc metallizing. To ensure the pulsed mode, the respective device was developed allowing control of outflowing of a jet with frequency within 0-130 Hz. Oscillograms of variation of dynamic pressure are given. Dependence of pulse atomizing air jet on frequency of closing the spray gun nozzle channel is shown. Coating microstructures are given. Influence of pulsation frequency on composition of coatings spray-deposited with PP-MM-2 wire is shown. 15 Ref., 6 Figures. [ABSTRACT FROM AUTHOR]

We report a diode-end-pumped midinfrared multiwavelength Er:Pr:GGG laser, generating the output powers of 324 and 354 mW in CW and pulsed modes, respectively. The slope efficiencies of CW and pulsed modes are 15.18% and 16.06%, respectively. Compared with Er:GGG, the laser properties of Er:Pr:GGG are much better and the self-termination bottleneck is broken successfully. The transverse beam profile and spectra of Er:Pr:GGG laser are measured and the relationship between lasing wavelengths and operating temperature in the triwavelength emission state are also studied. The Er:Pr:GGG crystal is a potential midinfrared laser gain medium in medical and military application. [ABSTRACT FROM PUBLISHER]