Discharge Lamps Research Articles

Study of the effect of argon glow discharge irradiation on the conformation of DNA molecules using laser spectroscopy methods

The aim of this work is to study the photochemical processes of hydrolysis of biomacromolecules, using the example of DNA in DNA and DNA-Polyethylene glycol (model of nucleoprotein) solutions. The processes induced by the line spectrum of an argon glow discharge lamp (AGDL) (700–1800 nm, 1.7–0.7 eV) have been studied by spectrophotometry, light scattering, turbidimetry, and spectrofluorimetry. It is shown that acridine orange (AO) intercalated in DNA is a good indicator of pH, i.e. of the presence of H3O+ ions in DNA solutions. H3O+ ions quench AO fluorescence and, in addition, eject it from the DNA in the solution. Using the methods of laser spectroscopy (light scattering, fluorescence, and resonance energy transfer) and spectrophotometry, we have observed hydrolysis of water solutions and of glycosidic and phosphodiester bonds in DNA and DNA-polyethylene glycol water solutions induced by near-infrared (700–1800 nm, (AGDL)) irradiation. The method is based on the difference between cancer and healthy cells because a normal cell has a perfect DNA repair system that makes near-infrared photo-irradiation non-invasive for them and lethal for a cancer cell. Using the turbidimetry method, the average size of the DNA aggregates from the calf thymus in a 150 mg ml−1 polyethylene glycol solution was determined and it is 250 nm in approximation that the aggregate has a spherical form. Aggregated DNA macromolecules are in B-form and the aggregate contains 12 · 106 b.p.

The growth and morphology of microgreens is associated with modified ascorbate and anthocyanin profiles in response to the intensity of sole-source light-emitting diodes

Sole-source light-emitting diodes (LEDs) are alternatives to fluorescent tubes and high intensity discharge lamps that are routinely used for indoor cultivation of horticultural commodities, including microgreens. This study examined the effect of photosynthetic photon flux density (PPFD) from LEDs on phytochemical profiles of organically grown kale, cabbage, arugula, and mustard microgreens, and their association with growth and morphological attributes. LEDs were used to deliver a 15% blue light and 85% red light mixture to microgreens at varying PPFDs between 100 and 600 μmol·m−2·s−1. For all microgreens, increased concentrations of ascorbate (total and reduced) and total anthocyanin were proportional to PPFD. Total phenolic concentrations were elevated in all four microgreens at high PPFDs, whereas chlorophyll concentrations declined in arugula, cabbage, and mustard. A principal component analysis revealed anthocyanins and phenolics were associated with ascorbate levels in all microgreens, but not with chlorophylls or carotenoids. At high PPFDs photosynthetic pigment levels were negatively associated with fresh and dry weight to varying degrees. Anthocyanins, phenolics, and ascorbate were negatively correlated with hypocotyl length and the colour attribute hue angle in all microgreens. These results indicate that microgreen growth and morphology are associated with altered phytochemical profiles during cultivation under sole-source LEDs.

Innovative Method of Treating Sintered Metal Powders Surfaces with Optical Radiation Pulses, Using Gas-Discharge Lamp

The research conducted in the present paper is part of a comprehensive study to innovate a method of surface treatment for some metallic powder materials with alternative energy sources to lasers and electron beams (i.e. with gas-discharge lamp (GDL)), typically used as sources of optical pumping for the lasers, having a solid active element. The radiant energy sources used for study are composed of a GDL and the high voltage power supply consists of a block of high-capacity capacitors. The materials were selected from the Fe-Cu-C grade, with a carbon content between 0.5 to 0.72%, and the measurements were made on microscopes with electron beam scanning. Configurational modifications of a surface layer of approximatively 30-35 im, characteristic for Fe-C-Cu alloys, containing nearly 0.7% C (pearlite, ferrite and cementite) are highlighted by the microscopic examinations. At the surface level, the energy flux created by the lamp in the visible spectrum, generates pressure, determining elongation of the surface layer pores, under optical action, resulting an effect comparable to plastic deformation by induration or compaction through mechanical actions. The results obtained highlight the potential of this class of materials to surface treatments and the options for the energy sources used.

Intelligent street lighting technologies for transport operation

The paper discusses a modern concept of smart street lighting that for illuminating city streets implies the use of special street lamps controlled via intelligent platforms. These platforms can regulate the intensity of lighting according to environmental conditions. At daybreak or when there is no people around, lamps’ brightness automatically decreases (or the lights entirely go down), which helps save electrical energy. As the result, expenditures from public funds on street lighting are reduced and the impact of electric power stations on the environment decreases. Street lighting is an essential part of the city infrastructure, since it performs several functions at ones. Firstly, it provides a sufficient level of illumination for traffic networks and pedestrian areas at night time, which not only enables reducing the number of traffic collisions and injuries, but also makes life of car drivers more convenient. Moreover, properly designed street lighting including street lamps on avenues, boulevards and in yards reduces the level of urban crime. Street lightning in Russia annually consumes approximately 7 billion kW/h of electric power, which is equivalent to 16 billion rubles. While producing such an amount of electric energy, millions of tons of various exhausts pollute the atmosphere. Smart street lighting systems help reduce the demand in electrical energy for outdoor illumination. The most important indicator of a civilized city is a well-lit roadway for transport – motorways. For transport on roads, various street lighting fixtures are used, but the most popular are energy-saving gas-discharge lamps, which effectively achieve full compliance with the standards and requirements for road lighting.

Landé gJ factors of the electronic levels of the europium atom

In the present work measurements of Landé gJ factors for some electronic levels of the europium atom are presented. The measurements were performed with the use of the Zeeman effect of the hyperfine structure, observed with the method of laser spectroscopy in a hollow cathode discharge lamp placed in constant magnetic field, with laser induced fluorescence detection. Investigation of 54 spectral lines of europium in the spectral range 511–662 nm enabled for the first time the determination of gJ factors for 16 levels belonging to the odd-parity configurations of Eu and 4 levels belonging to the even-parity configurations. Moreover, 3 gJ values for levels belonging to the even-parity configurations, previously known from the literature, were corrected.

Low-Pressure Photoionization in a Dual-Ion Funnel Injector Coupled to an Orbitrap Mass Spectrometer for Direct Analysis of Human Breath and Head-Space Sampled Coffee Roasts.

Low-pressure photoionization (LPPI) is a versatile tool for the mass spectrometric detection of (semi-)volatile organic compounds, (s)VOC. Here, a dual-ion funnel MALDI/ESI ion injector was equipped with a direct-inlet LPPI module. A radio-frequency (RF) drive enabled the implementation of three Kr discharge lamps in a novel design optimized for efficient photoionization and undisturbed ion trajectories. Supported by expansion and collisional cooling and, optionally, dopant vapor, primarily intact radical ions and protonated molecules were generated. Molecular identification was supported by the high-resolving power of an Orbitrap mass analyzer. In our proof-of-concept study, exhaled human breath and head-space sampled coffee grounds were characterized with this high-throughput technique. From breath, a few hundred and for the coffee roasts more than thousand distinct (s)VOC features were recorded. Principal component analysis enabled the differentiation of coffee grounds by origin and roasting protocol.

Experimental Demonstration of the Effect of the Externally Applied Magnetic Field on the Plasma Optical Radiation Spectrum of the Glow Discharge Lamps which are used as milimeter wave/Terahertz dedectors

Bu çalışmada, Parıltılı deşarj lambaları (GDD) içindeki plazma bölgesinde meydana gelen optikışımada meydana gelen, milimetre dalga radyasyon ve harici elektromanyetik alana bağlı değişimlergözlemlenmiş ve ölçülmüştür. Milimetre dalganın (MD) tek başına uygulandığı zaman optik ışımadagörülen etkinin göreceli olarak %3 civarı olduğu görülmektedir. Elektromanyetik alanın (EM) etkisi ileışınımda %5’lik bir artış oluşmaktadır. 600 Gauss şiddetinde bir manyetik alanın uygulanması, plazmabölgesi optik ışımasının milimetre dalga radyasyona karşı hassasiyetini 0.4 dB kadar arttırmıştır. Dahayüksek manyetik alan değerlerinin denenmesi planlanmıştır.

Study of the brazing physicochemical processes of structural elements of the gas discharge lamps with sapphire shell

ABSTRACT In the present work, the results of the research gas discharge lamp constructive elements those made from niobium and zirconium alloy, sealing by means of melting titanium with its alloy with nickel are presented. It is performed construction peculiarities analysis of gas discharge lamp with sapphire shell. The requirements to sealing materials are formed. It is studied physical and chemical processes occurring in materials during lamp sealing and lifetime.

Calculation of Net Emission Coefficient for High Intensity Discharge Lamps

There is still great interest in studying high intensity discharge (HID) lamps despite the great development of other light sources like light emitting diodes (LEDs). Basic equations and numerical formulations allow calculating important terms such as the net emission coefficient (NEC) that plays an important role in understanding the radiation behaviour of these lamps. These lamps are considered to be at high pressure and the produced plasma was found to be at local thermodynamic equilibrium (LTE). The volume of the lamp is meshed into small cells and the total number of cells represents a compromise between correct results and calculation time. Each cell has its own local absorption and emission coefficient that applies to its position in the discharge. Line profile is calculated by two profiles convolution: one is Lorentz’s and the second one is a quasi-static profile. Ray tracing technique is used to resolve the radiation transport for the visible and ultra violet (UV) spectrum. The NEC is thus calculated and compared with other models for a pure mercury discharge. In addition, additional photometric properties of the lamp are obtained.

Comparison on Lamp Characteristics of Highway Tunnel Lighting System

This paper introduces the expression form of the light field of the light source and the description method of the light intensity distribution characteristics, and details the different types of lamps in the tunnel lighting system from the principle of light emission, optical characteristics and application scope. A comprehensive comparison of performance. The results show that LED lights have high efficiency, long service life, and excellent color rendering, which are in line with the concepts of energy saving, emission reduction, and environmental protection. They have huge room for technological improvement and will gradually replace gas discharge lamps as the main light source for tunnel lighting.

Microwave gas-discharge device OVOD-1a sanitizing indoor air

A new UV scanning system OVOD-1a for the indoor air environment, based on high-performance microwave gas-discharge lamps developed at GPI RAS, is described. The first experiments demonstrating the air-cleaning capabilities of UV equipment were carried out. It is shown that in laboratory rooms used for the stay of livestock bred in agriculture, the energy cost of almost complete purification of the air environment from viral and fungal components is of the order of 10−2 kW × h/m3. B acter ial sanita tio n o f the laboratory p re mise s o f the research physical Institute is carried out with an energy cost of ≍ 3 10−3 kW×h/m3. The fundamental physical processes underlying microwave UV lamps, which are the main component of the OVOD-1a sanitation system, are discussed.

Borosilikat Camlar

Thanks to their distinguished properties borosilicate glasses (BSGs) are preferred in many application fields: laboratory glassware, microwave glass cookware, high quality beverage glassware, aquarium heaters, flashlights, spotlights (high–powered lighting products), high intensity discharge lamps, telescopes, bio materials, immobilisation and disposal of radioactive wastes, microscope lenses and slides, art construction, aviation (airplanes, UAVs, missiles) etc. The aim of this work is to present general information about BSGs from past to present time.

Investigations of the hyperfine structure and isotope shifts in the even-parity level system of atomic europium

This work presents the measurements of the hyperfine structure constants A and B, as well as the isotope shifts, for 26 electronic levels belonging to the even-parity configurations at the energy range 28000–40000 cm−1 in the europium atom. The measurements were performed with the use of laser spectroscopy with a hollow cathode discharge lamp as the source of the atoms and the detection of laser induced fluorescence. Among the results obtained, 10 levels were measured for the first time, in the case of another 3 levels results somewhat more precise than the earlier published ones were obtained. The A and B hyperfine structure constants’ values were determined on the basis of the measurements on 73 spectral lines located in two wavelength ranges: 480–560 nm and 625–680 nm.

Arm Cortex Based Auto Intensity Controller

The general street lights which are in use are High Intensity Discharge Lamps of which the intensity controlling is not possible by any voltage reduction method as the discharge path would be broken and they are based on the principle of gas discharge. Due to the rate of the power the LEDs consume and the durability of them is replacing the other lights with these rapidly all over the globe. The Pulse Width Modulation can help in controlling the intensity of the white LED but not the usual lamps which are used. The major aim of the intensity control is that the power consumption would be less when compared and saves a lot of energy. It is a repetitive process and never ending, it gets switched on when it gets gloomy and gets switched off where there is abundant light available. The project of ours aims to save energy by using the LED for street lights with auto intensity control using solar power which adds to the energy saving as well. These days the solar energy is being used by most of the people as they know its importance now.

Measurements of experimental transition probabilities of 3p54p → 3p54s arrays in neutral argon.

We have determined the absolute transition probabilities of 27 emission lines of neutral argon originating from the 3p54p→3p54s transition array in the wavelength region from 650 to 1100 nm using an argon-filled hollow cathode discharge lamp. The absolute transition probabilities have been deduced using the lifetimes of the upper levels and the measured branching fractions. Atomic oscillator strengths and relative line strengths for all the transitions have been computed using calculated transition probabilities. The experimentally determined transition probabilities are found to be in good agreement with that calculated in the intermediate coupling (IC) scheme. The comparison of experimentally determined transition probabilities with reported theoretical transition probabilities confirms that the IC scheme for the lower as well as for the upper levels seems to be a useful scheme for the level designation for the 3p54p to 3p54s configuration-based levels in argon. Furthermore, the measured relative line strengths are used to validate the J-file sum rule for the 3p54p→3p54s transition array of argon. The reported transition probabilities, oscillator strengths, and relative line strengths are compared with the published data, showing good agreement.

Measurements of branching fractions, absolute transition probabilities and J-file sum rule for the 4p55p→4p55s transitions array in neutral krypton

We present new results of transition rates for twenty two electric dipole transitions of neutral krypton associated with the 4p55p→4p55 s configurations-based levels covering the wavelength region from 500 to 1000 nm using a krypton filled hollow cathode discharge lamp coupled with a set of four miniature spectrometers. The branching fractions of various dipole allowed transitions were extracted using the observed line intensity ratios, whereas, the absolute values of the transition probabilities were deduced from the measured branching fractions in combination with the known lifetimes of the upper levels. The experimental data are in good agreement with that calculated in the intermediate angular momentum coupling scheme. In addition, line strengths for all the transitions have been extracted using the measured transition probabilities. The J-file sum rule was also tested for each level attached to the 4p55p→4p55 s configurations based on the recently measured and calculated normalized multiplet strengths.

The memristive system behavior of a diac

The memristor was introduced as a nonlinear circuit element in 1971, and systems showing memristor-like properties such as zero-crossing hysteresis loops were described in 1976. In 2008, a thin-film system that behaved like a memristor over some part of its operating region was discovered. Memristors and memristive systems have thus become a hot research area in recent years, making it important to discover and study such systems that show memristive behavior. Memristors and memristive systems exhibit three distinguishing characteristics that are known as their three fingerprints. Discharge lamps were also shown to exhibit memristive behavior recently. The diac, an electronics component commonly used in alternating-current (AC) applications, exhibits a breakdown mechanism similar to that observed in discharge lamps. According to textbooks, a diac should also obey the characteristics of a memristive system. In this work, a phenomenological model for a diac is first presented, and it is shown that this model satisfies the description of a memristive system; circuit simulations are also used to verify the memristive system behavior of a diac. However, experiments performed on a DB32 diac reveal that it only behaves like a memristive system in a narrow frequency range around 1 kHz. The effect of the junction capacitances of the diac are found to be important in this regard, resulting in the deviation of the diac from the expected memristive system behavior, as supported by the model and circuit simulations. We also believe that the reverse recovery current at frequencies above 1 kHz inhibits the zero-crossing behavior of the diac, even though its hysteresis curve is very similar to that of a memristive system.

The technique of calculating the profile of a mirror reflector for discharge lamps of cylindrical shape and its testing on the example of design of an industrial lamp type ZhSP-250

Current scientific trends are developments - methodological, theoretical and experimental, related to increasing the efficiency of some categories of lamps with discharge lamps. One such category is the powerful industrial spotlight class luminaires. This work is aimed at solving the urgent scientific task of finding ways to improve the design efficiency of industrial luminaires with deep and concentrated light distribution. At present, there are practically no works related to the task of calculating the geometry of the profiles of mirrored round-symmetric reflectors, which, in the presence of a light source of a fixed type and power, would provide the necessary light distribution of the luminaires. The elemental reflection method described in classical works does not determine the geometry of the reflector correctly, which provides the necessary balance in the equation that relates the light power of the lamp to the light power of the source and the reflector. The considerable time of calculation by the classical method and obtaining inaccurate decisions leads to rethinking the solution of the problem of calculating the geometry of the the reflector profile of the lamp with rigidly regulated light distribution. This task was first formulated by us in previous works. The purpose of this work is to approve the technique of solving the inverse problem of determining the geometry of a round-symmetric mirror reflector on the example of an industrial lamp type ZhKU-250 with light distribution type G-2. As the output of the calculation we used the light source and technical characteristics of the light source - DNAT-250 lamps, the required light distribution of the light fixture, the reflectance of the reflector, and the requirements for the efficiency of the designed luminaire and its gain. As a result of the performed work, it is possible to note the efficiency of the method both in terms of the accuracy of the calculations and the simple geometry of the reflector, obtained in the calculation method, which will allow to use simplified technological schemes for the serial production of such lamps. Keywords - industrial luminaires, DNaT discharge lamps, reflector LPC (Light Power Curve) required, zone LPCs of the reflector, radius vector array, luminaire gain and efficiency, elemental reflection method, reflector profile, rotary extrusion method.

Preventing method of acoustic resonance in the high-pressure discharge lamps

Abstract The article analyzes available methods for preventing acoustic resonance of high pressure lamps. A new method is proposed, the main idea of which is the filing of a high-voltage lamp modulated by a pseudo-random signal. An analysis of the spectral characteristics of the signal entering the lamp is made, the mathematical modeling of the set of a “discharge lamp - prototype of the device” - is implemented, which implements the proposed control method of the lamp. The results of simulation and oscillograms, taken from the prototype, which confirms the results of theoretical research, are presented.

Power Losses in RF Inductor of Ferrite-Free Closed-Loop Inductively-Coupled Low Pressure Mercury Lamps

RF inductor power losses of ferrite-free electrode-less low pressure mercury inductively-coupled discharges excited in closed-loop dielectric tube were studied. The modelling was made within the framework of low pressure inductive discharge transformer model for discharge lamps with tubes of 16, 25 and 38 mm inner diam. filled with the mixture of mercury vapour (7.5×10–3 mm Hg) and argon (0.1, 0.3 and 1.0 mm Hg) at RF frequencies of 1, 7; 3.4 and 5.1 MHz and plasma power of (25–500) W. Discharges were excited with the help of the induction coil of 3, 4 and 6 turns placed along the inner perimeter of the closed-loop tube. It was found that the dependence of coil power losses, Pcoil, on the discharge plasma power, Ppl, had the minimum while Pcoil decreased with RF frequency, tube diameter and coil number of turns. The modelling results were found in good qualitative agreement with the experimental data; quantitative discrepancies are believed to be due skin-effect and RF electric field radial inhomogeneity that were not included in discharge modelling.