Copper Vapor Research Articles

Analysis and experiment of structural geometry for improved strain sensitivity of FBG sensors

AbstractThis paper presents analysis and experimental studies to significantly enhance the strain sensitivity of fiber Bragg grating (FBG) sensors by suitably modifying the host structure used for mounting the FBG. The proposed host structure is a novel, compact flexure beam-based design, specially engineered to amplify and convert horizontal strain into vertical strain more effectively. Its unique geometry includes circular sections for hinge connections, resulting in improved displacement amplification and reduced stress across the structure. Using ANSYS calculations and finite element analysis, simulations were conducted to evaluate the vertical deformation, stress, and longevity of the sensor's mechanical structure. Results from these simulations indicate an enhanced strain sensitivity of approximately 15.633 pm/με, a significant improvement over the 1.191 pm/με sensitivity observed with bare FBGs. Experimental tests were carried out on fabricated sensor structures to validate the enhancement in strain sensitivity. FBGs utilized in the experiments were inscribed using a 255 nm UV beam generated from a second harmonic copper vapour laser. The strain sensitivity of FBGs mounted on the optimized structure was found to increase up to 9.95 pm/με. The difference between simulation and experimental results are attributed to the partial absorption of strain by the adhesive used to affix FBGs.

Two-frequency pulsed laser irradiation to stimulate the development of coniferous trees

The possibility of using radiation from a two-frequency pulsed copper vapor laser with wavelengths of 510.6 nm and 578.2 nm with an exposure of 30 to 120 s to stimulate the development of coniferous trees (spruce, pine, larch) with a single seed irradiation is shown. The stimulation effect manifests itself at various early stages of development, such as the awakening of seeds in the aquatic environment in the first hours of the experiment (according to electron absorption spectroscopy data), seed germination, and seedling growth under stressful cultivation conditions. Possible causes of light exposure to plant seeds are discussed.

Biological effect of dual-frequency laser pulse radiation during pre-sowing treatment of rice seeds at early stages of development under stressful environmental conditions

The biological effect of two-frequency laser pulsed radiation produced on copper vapor during pre-sowing treatment of rice seeds of Veles and Leader varieties at early stages of development in extreme stressful environmental conditions has been studied. The copper vapor laser used in the experiment had the following output characteristics: wavelengths of 510.6 nm (green radiation line) and 578.2 nm (yellow radiation line), pulse duration of 15 ns, repetition frequency of 10 kHz, total pulse power of 10 kW, energy-power ratio between the green and yellow radiation lines 3/1 The interaction of laser radiation with wavelengths of 510.6 and 578.2 nm in the nonlinear medium of the seed caused the formation of additional wavelengths: a total wavelength of 271 nm (ultraviolet radiation) and a difference wavelength of 4.37 microns. Exposure to each of the four wavelengths in its spectral range could lead to the initiation of at least four radiation-induced biochemical reactions. It is shown that pre-sowing treatment of rice seeds with two-frequency laser pulsed radiation for 5–20 seconds had a stimulating effect on the growth and development of rice (the greatest effect was when exposed to 5–10 seconds), and also increased its stability when grown in extreme stressful environmental conditions (moisture deficiency, depleted soil) at early stages of development.

An electromechanical shutter for a medical copper vapor laser system

An electromechanical shutter for a medical copper vapor laser system

A Systematic Review of Laser Treatment for Angiofibromas in Tuberous Sclerosis.

While mammalian target of rapamycin inhibitors have revolutionized the management of angiofibroma in tuberous sclerosis complex (TS), physical modalities such as laser are still indicated for recalcitrant lesions. The authors performed a systematic review of the efficacy and safety of laser treatment for TS-related facial angiofibroma. The electronic databases such as MEDLINE, Embase, PubMed, Cochrane Central Register of Controlled Trials, and Web of Science were searched from inception to October 10, 2023, for eligible records. Forty-seven articles met the inclusion criteria, representing a total of 217 patients with TS-related facial angiofibroma who received laser treatment. Several lasers have been trialed in patients including carbon dioxide ( n = 95, 43.7%), pulsed dye ( n = 21, 9.7%), argon ( n = 16, 7.4%), neodymium-doped: yttrium aluminum garnet ( n = 12, 5.5%), copper vapor ( n = 9, 4.1%), potassium titanyl phosphate ( n = 7, 3.2%), erbium: yttrium aluminum garnet ( n = 2, 0.9%), lasers and various combination therapies ( n = 55, 25.3%). Potassium titanyl phosphate, pulsed dye, and neodymium-dopsed:yttrium aluminum garnet lasers are better suited to manage the vascular components of angiofibroma while ablative lasers such as erbium: yttrium aluminum garnet and carbon dioxide lasers may present better options for lesions with a prominent fibrous component. While several lasers have been trialed with broadly favorable results, the low level of evidence precludes definitive conclusions, and no single laser appears superior.

Nanosecond pulsed laser ablation of synthetic graphite in liquids for the synthesis of spherical graphene

Pulsed laser ablation in liquids has become a simple, fast, and environmentally friendly method for the synthesis of carbon nanostructures since it does not require the use of toxic chemicals. The great advantage of this method is its ability to control the size, shape, and structure of the products by combining parameters of the laser, target material, and liquid. By ablation of two types of synthetic graphite with a high-power copper vapor laser in ethanol and distilled water, spherical graphene was obtained. The composition of the gas phase and the condensation temperature of carbon in the temperature range of 1000–5000 K were determined by means of thermodynamic modeling. The precursors for the formation of spherical graphene during laser ablation in alcohol and water are discussed.

Synthesis and Characterization of SiO2-Based Graphene Nanoballs Using Copper-Vapor-Assisted APCVD for Thermoelectric Application.

This study describes a method by which to synthesize SiO2-based graphene nanoballs (SGB) using atmospheric pressure chemical vapor deposition (APCVD) with copper vapor assistance. This method should solve the contamination, damage, and high costs associated with silica-based indirect graphene synthesis. The SGB was synthesized using APCVD, which was optimized using the Taguchi method. Multiple synthesis factors were optimized and investigated to find the ideal synthesis condition to grow SGB for thermoelectric (TE) applications. Raman spectra and FESEM-EDX reveal that the graphene formed on the silicon nanoparticles (SNP) is free from copper. The prepared SGB has excellent electrical conductivity (75.0 S/cm), which shows better results than the previous report. Furthermore, the SGB nanofillers in bismuth telluride (Bi2Te3) nanocomposites as TE materials exhibit a significant increment in Seebeck coefficients (S) compared to the pure Bi2Te3 sample from 109 to 170 μV/K at 400 K, as well as electrical resistivity decrement. This approach would offer a simple strategy to improve the TE performance of commercially available TE materials, which is critical for large-scale industrial applications.

Variable repetition rate pulse power supply based on magnetic pulse compression for copper vapor lasers

Variable repetition rate pulse power supply based on magnetic pulse compression for copper vapor lasers

Investigation of the dielectric recovery process of vacuum arc in double breaks by planar laser-induced fluorescence

The multibreak vacuum circuit breaker uses multiple short gaps to interrupt the fault current, greatly improving the dielectric strength, and is a viable method to realize high-voltage interruption. The metal vapor distribution near the current zero is crucial for the dielectric recovery process in the multibreak vacuum circuit breaker. Due to the complicated dielectric construction and the interaction between the breakers, the vacuum arc inevitably deviates from the axisymmetric distribution during the interruption process. The traditional diagnosis method limited to 0D or 1D is not sufficient to study the real distribution of metal vapor near the current zero. To address these issues, we developed a planar laser-induced fluorescence method to measure the 2D distribution of copper vapor near the current zero by detecting 510.6 nm fluorescence intensity. The results indicate that for the butt contacts, the copper vapor is diffused in the gap of the high-voltage break and aggregated on the cathode surface of the low-voltage break. The axial magnetic field and transverse magnetic field affect the 2D copper vapor distribution and eliminate the inconsistency, which is achieved by affecting the motion of charged particles and the ionization-recombination process. Furthermore, the copper vapor density exhibits a positive dependence on the arc current, and the magnetic field impacts the density increase rate and distribution mode.

Micromachining of Metals with Copper Vapor Laser

Micromachining of Metals with Copper Vapor Laser

Surface blackening of titanium alloy by laser nanosecond pulses

The possibility of developing and blackening the surface of titanium alloy by nanosecond pulses of an ArF laser, a Nd:YAG laser, and a copper vapor laser for use in space engineering is studied in this work. For various irradiation regimes, the optimal parameters for the formation of the necessary surface structures were determined. The possibility of applying a reliable color layer without the use of any paints on the surface of a titanium alloy as a result of treatment with an Nd:YAG laser beam is shown. In particular, this method of laser processing will make it possible to obtain black color on the surface of devices used in outer space to absorb and dissipate solar energy, and it is expected to increase the radiation resistance of such coatings and their service life.

Enhancement the production of trays solar still via nano phase change material and preheating feed-water

The researchers devise novel approaches to find freshwater meeting to growing industry and population. Solar stills can create drinkable water, although their output isn't exceptionally high. The goal of this work was to improve the rate of evaporation of a trays solar still (TSS) by implementing four modifications. An experimental investigation has been conducted using both a conventional solar still (CSS) and a modified TSS. The modified TSS has been tested by employing two copper spiral water heating coils, internal reflectors, vapor exhaust fan, and phase change material mixed with Nano (PCM-Ag Nano). In five sets of testing, the performance of trays SS and CSS was compared under the same environmental conditions. Results achieved indicated that, the total yield of the TSS with copper coils, internal reflectors and PCM-Ag was enhanced by 146 % over that of the CSS. Additionally, the total freshwater production of the TSS was enhance by 164 % when using copper coils, internal reflectors and vapor exhaust fan in comparison to the CSS. Under these conditions, the distillation values of conventional distiller and modified TSS were 3200 and 8450 mL/m2.day. Addition, the reported costs for treating water for CSS and modified TSS with modifications were found to be 0.026 and 0.018 $ per liter. The environmental parameter of modified TSS was 34.2 tons of CO2 per year.

Modeling and simulation study on the ablation characteristics of DC contactor contact

The DC contactor can frequently break the high current control circuit, and the arc motion characteristic in the current breaking process is closely related to its electrical life and reliability. In this paper, a three-dimensional magnetohydrodynamic arc model of the DC contactor considering contact motion and external circuit characteristics is established. On this basis, the influence of the vapor produced by the contact ablation on the arc behavior is studied, and the ablation rate of the cathode in a single breaking process is calculated. The results show that the arc temperature is reduced, the motion speed is slowed down, and the arc burning time is shortened due to the presence of copper vapor produced by ablation. The ablation rate of the cathode during a single arc is 8.9 µg/C.

Cathode sheath parameters and their influences on arc root behavior after liquid metal bridge rupture in atmospheric air

The cathode sheath (CS) formation of the direct current air circuit breaker is simulated by a fluid model, and the influence of metal vapor concentration between the contacts after liquid metal bridge rupture is considered. The CS conductivity increases with the increasing concentration of copper vapor. The copper vapor concentration increases from 5% to 95%, and the thickness of the positive space charge layer and ionization layer increases from 22.3 and 49.1 μm to 51.8 and 81.7 μm, respectively. Increasing the CS conductivity is beneficial for the motion of arc roots in a certain range.

Effect of Copper Vapor on Radiation Properties of C4F7N Gas Mixtures

C4F7N and its mixture with buffer gases are regarded as the most promising SF6-alternative gases in gas circuit breakers. The switching arc can severely ablate the electrodes, producing copper metal vapor that combine with the C4F7N gas mixture to chang radiation characteristics. This paper compares the net emission coefficient of C4F7N mixtures at various mixing ratios and assesses the effect of 20% copper vapor. It is found that adding copper vapor can greatly enhance radiation.

Effect of gas mixture pressure on detection sensitivity of molecular iodine in the atmosphere by laser-fluorescent method using a copper vapor laser (578.2 nm)

The paper reports on the calculation studies of the influence of the pressure of the analyzed gas mixture on the measuring sensitivity of the concentrations of 127I2, 127I129I and 129I2 in atmospheric air by the laser-fluorescence method using a copper vapor laser with a wavelength of 578.2 nm as a fluorescence excitation source. It is shown that for each of these iodine molecules there are pressures at which the highest fluorescence intensity is achieved, which correspond to the best detection sensitivity of the molecules. The results obtained can be used in the development of methods for real-time detection of molecular iodine in the atmosphere.

Experimental investigation on “glow flow” phenomenon during current-zero period between transverse magnetic contacts

The inter-electrode state of the transverse magnetic field contact during the current-zero period is determined by the evolution of the arcing process. It has an important effect on whether the vacuum switch can be successfully broken. In this paper, a series of contacts were subjected to arcing and fixed gap distance experiments. The results show that a special inter-electrode phenomenon (glow flow) appears during the current-zero period when the current exceeds the threshold for the transition from diffused to constricted state of the vacuum arc. The mechanism behind the formation of this phenomenon was elucidated through an analysis of multiple sets of experimental results. It is found that the inter-electrode phenomenon arises from the disruption of the equilibrium process between the pressure from the arc column plasma and the anode vapor flux on the near-anode side at the current-zero. The copper vapor falls and is ionized by collisions with heat-emitting electrons. The experimental results and theoretical analysis also show that this phenomenon has a time interval with the reignition phenomenon. When this phenomenon is intense to a certain degree, the reignition will occur with high probability. The observation and theoretical analysis results of this paper are relatively consistent with the research results of other scholars, which can help to improve the vacuum arc characteristics and interrupting mechanism. This can provide a basis for improving the arc extinction performance of the vacuum switch.

Transcutaneous selective laser photodestruction for the treatment of petechial arachnoid capillary angiodysplasia of the skin in children

Introduction. Petechial – arachnoid capillary angiodysplasia (PACA) of the skin is an acquired pathological benign vascular formation that is met in 66% of children aged 4–9. PACA looks like a spider with a vascular red spot in the center and thin vascular rays coming from it. PACA has a benign course; it is slowly and gradually growing over time, and in rare cases it can disappear spontaneously. There have been proposed some techniques for removing PACA: cryodestruction, electrocoagulation, laser coagulation – with CO2-laser light (wavelength 10.6 mkm), copper vapor laser (wavelength 511 and 578 nm), pulsed dye laser (wavelength 585–595 nm). The main disadvantage of cryodestruction, electrocoagulation and laser coagulation with CO2-laser is a high risk of scarring, hyperpigmentation and frequent relapses. While irradiation with copper vapor laser and pulsed dye laser requires repeated exposures to achieve optimal results.Purpose. To improve outcomes in managing children with PACA using a new modality of transcutaneous selective laser photodestruction.Material and methods. For the last two years, 61 children having PACA were treated with transcutaneous selective laser photodestruction in Clinical and Research Institute of Emergency Pediatric Surgery and Trauma (Moscow, Russian Federation ). The researchers used “green” laser light having the following parameters: wavelength 520±10.0 nm, peak power 2.0±0.5 W, pulse duration 1.9 ms, pulse frequency 50 Hz, exposure time 2.0±0.5 sec.Results and discussion. 59 patients had no any residual elements after the first session; the other two had repeated photodestruction because of residual elements. No scar deformity was seen in any of 61 cases after treatment.Conclusion. The present clinical trial has demonstrated that transcutaneous selective laser photodestruction, if to consider spatial localization of PACA structural elements in the skin, allows to precisely irradiate only the central vascular element and to achieve radically good clinical and esthetic outcomes after treatment.

Evaluation of Conducted Electromagnetic Interference Behavior of Copper Vapor Laser

High power and high repetition rate electrically excited copper vapor laser (CVL) is a strong source of radiated and conducted electromagnetic interference (EMI). The thermal energy required to raise the temperature (∼1600°C) to generate copper vapor and the required voltage pulse for population inversion is provided by the pulse generating unit (PGU). The PGU generates a voltage pulse of the order of ∼13 kV with a rise time of less than 100 ns and a current pulse in the range of ∼500 A with a similar rise time. The high voltage and current generated by PGU along with the high voltage pulse discharge in the laser tube serves as a prominent source of EMI and affects the performance of nearby electronic devices. This article presents a comprehensive study of conducted EMI from a high-power and high voltage discharge inside the CVL system and its impact on laser performance. The conducted noise from the laser is a function of laser impedance and is proportional to the magnitude of load mismatch. A simple and robust technique is presented to reduce the conducted noise from CVL. The correlation between the laser electrode pin configurations and the conducted noise is also presented.

Prospects for Improving the Energy Characteristics of a Copper Vapor Laser

Prospects for Improving the Energy Characteristics of a Copper Vapor Laser