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This paper deals with a model that simulates an electrodeless lamp with argon/mercury chemistry. The plasma kinetics model equations were solved using COMSOL (multiphysics simulation software) with appropriate boundary conditions. The numerical modeling of inductively coupled plasma is of crucial importance to understand the behavior of different physical quantities that characterize the ionized gasses such as electrical parameters. The electric and magnetic fields were handled by the electromagnetic model using the multiturn coil method. Results are in fairly good agreement with the experimental data from the literature and fit well with the expected physics of the discharge plasma. [ABSTRACT FROM AUTHOR]

Abstract Microwave electrodeless discharge lamp (MEDL) has been regarded as a powerful light source of photoreaction. Four kinds of chemicals, nitrogen (N 2), oxygen (O 2), water (H 2 O) and dimethyl sulfide (DMS), were used as molecular probes to explore the generation process of reactive oxygen species (ROS) and their photo-oxidation performances on the photodegradation of organic pollutants with application of an exterior MEDL system. ROS such as O (3P), O 3 , O (1D) and 1O 2 were generated via irradiation of O 2 and H 2 O except dry N 2 by MEDL. They were transformed to other ROS including ·OH and H 2 O 2 with increase of relative humidity. The ROS productivity was inhibited evidently by humidity and ·OH became the major active species at high humidity. An optimal mineralization rate of 23.6% for DMS photodegradation was reached in dry air compared with 8.74% at high humidity, which indicated that O (1D) and 1O 2 were more powerful oxidants than O 3 and OH. The results showed that the higher mineralization rate of organic pollutants was obtained by increasing the generation efficiency of ROS of O (1D) and 1O 2. Furthermore, the results provided an alternative to develop intensification technology on photodegadation of organic pollutants with MEDL system and an optimal operation process including photocatalyst and humidity. Graphical abstract Image 1 Highlights • N 2 , O 2 , H 2 O and DMS were used to investigate generation process and photo-oxidation property of ROS. • The atmosphere and humidity greatly affected the generation types and quantities of ROS. • O (1D) and 1O 2 were the main active resources to contribute the DMS mineralization. • High humidity promoted DMS to be decomposed to small intermediates other than inorganic salts. [ABSTRACT FROM AUTHOR]

Highly sensitive chemical warfare agents (CWAs) detection is demanded against the usage of the CWAs for war or terrorism aims. A dimethyl methylphosphonate (DMMP), simulant for sarin, monitoring sensor based on a homemade wireless-electrodeless quartz crystal microbalance with dissipation (QCM-D) was developed. With this noncontact configuration, deterioration of the sensing ability cause by the electrodes and drilling on the gas chamber for wire lead was avoided. Nano-structured hollow ball-like indium oxide (In 2 O 3 ) was synthesized using a facile hydrothermal method and then decorated with cubic gold particles (In 2 O 3 -Au). Both of them were applied as the sensing films to detect DMMP. The In 2 O 3 -Au based QCM-D sensor exhibited 2.1 Hz/ppm to DMMP range from 5 ppm to 50 ppm, which was 400% higher compared to the undecorated one. Moreover, with the simultaneously monitored dissipation value, desorption processes of DMMP was further investigated and the overshoot that appear in some researches was explained in terms of visco-elastic variations in mechanical stiffness. The results suggest that the wireless-electrodeless QCM-D could be a promising strategy for observation of materials under dynamic conditions. [ABSTRACT FROM AUTHOR]

The electronic devices, which contain single phase rectifiers, have significant harmonics emissions. Modern lamps are driving by electronic ballast, which contains single phase rectifiers. The modern lamps are nonlinear loads and introduce harmonic distortions in power supply lines. In conformity with standard requirements the emission measurements are done for a single lamp during the validation process. In real life more than one lamp is used at the same time in a system. Measurement of more modern lamps in a circuit shows that the harmonics emission in their case is lower than in the case of one lamp. [ABSTRACT FROM AUTHOR]

We report the hyperfine Structure ( hfs ) splitting observations of neutral iodine atom (II) in the 6000 – 10,000 cm −1 near infrared spectral region. The measurements were carried out using a high-resolution Fourier Transform Spectrometer (FTS), where an electrodeless discharge lamp (EDL), excited using microwaves, was employed as the light source and InGaAs as the light detector. A specially designed setup was used to lower the plasma temperature of the medium so as to reduce the Doppler width and consequently to increase the spectral resolution of hfs components. A total of 183 lines with hfs splitting have been observed, out of which hfs in 53 spectral lines are reported for the first time. On the basis of hfs analysis, we derived the magnetic dipole and electric quadrupole coupling constants, A and B respectively for 30 even and 30 odd energy levels and are compared with the values available in the literature. New hfs values for 5 even and 4 odd levels are also reported here for the first time. [ABSTRACT FROM AUTHOR]

Iron was determined in drinking water using low-cost, disposable, and highly reproducible modified graphite screen-printed electrodes. Nafion is a chemically inert polymer and endows remarkable sensitivity for Fe(III) through interaction with the sulfonic groups on the polymer surface. The concentration of Nafion on the modified electrodes was optimized and the best results were obtained using 2 μL of 0.2% Nafion in ethanol. The preconcentration of analytes was performed in an electrodeless mode with stirring in 0.01 mol L-1 HCl. Under selected conditions and for a preconcentration time of 60 s, square-wave voltammograms exhibited a cathodic peak, the height of which was linearly dependent on the concentration of iron from 0.05 to 5.00 μmol L-1. The limit of detection was 15 nmol L-1 Fe(III). The developed electrodes were successfully used to determine iron in tap water. Accuracy of the method was evaluated with recovery measurements in spiked samples. The values were 108 × 3%. Possible interferences from the coexisting ions were also investigated. The results show that the sensors are sensitive, selective, rapid, reliable, and suitable for the determination of Fe(III) in water. [ABSTRACT FROM AUTHOR]

The photolytic degradationmechanism of atrazine using a UV reactor andUV/MW (electrodeless discharge lamp (Hg-EDL)) was investigated. After 120 s of UV photolysis partial degradation of atrazine had been observed and a subsequent formation of degradation products of atrazine-2-hydroxy, therefore, defining the path of atrazine degradation through UV photolysis. This system after 1200 s of exposure to UV radiation had not reached full degradation of atrazine, and its metabolite (atrazine-2-hydroxy), was the main by-product obtained for the process. When performing photolysis through the UV/Microwave combined methodcomplete atrazine degradation was obtained within a 5 s interval, besides the formation of five (5) degradation products, which are HAT, DEAT, DIAT, DEHAT and DIHAT. Therefore, defining the path of the photolytic degradation process through the UV/Microwave combined method. The total degradation of its metabolite (HAT) was observed for the period of 120 s of exposure to UV/MW radiation, and after that time there had been no signcorresponding to the respective compounds. The tests with the isolated microwave radiation were not efficient in the degradation of the atrazine and, therefore, the respective isolated energy is not applicable.The control of atrazine degradation and consequent formation of metabolites were accompanied by a high-performance liquid chromatography with a UV/Vis detector. [ABSTRACT FROM AUTHOR]

In this study, an electromagnetic induction electrodeless lamp (EIEL) was first introduced into UV advanced oxidation processes (AOPs) for photodegradation of Diatrizoate (DTZ), which was the most persistent iodinated X-ray contrast medium (ICM), and traditional Hg lamps were taken as references. Direct photolysis rate of DTZ under EIEL irradiation was 1.34 times as that under Hg irradiation, but the electric energy consumption was 0.87 times. In this sense, the combination of EIEL and oxidants (O 2 , H 2 O 2 and S 2 O 8 2− (PS)) was further investigated. The remarkably increased photodegradation rates were observed in UV/PS system due to primary contribution rate of SO 4 − (62.5%) based on the results of radical concentrations and second-order rate constants of DTZ with SO 4 − and OH. Inorganic ions influencing the photodegradation process were investigated. The effect of natural organic materials (NOMs) in UV/PS system was studied based on contribution ratios of light screening effect and quenching. Transformation mechanisms of DTZ in UV/PS system included deiodination, intramolecular cyclization, decarboxylation, deacetylation and deamination, which were further confirmed by frontier electron density calculations. The study indicated that UV/PS with EIEL irradiation has the potential to remove pharmaceuticals in contaminated aquatic environments. [ABSTRACT FROM AUTHOR]

BACKGROUND Disinfection is an essential way to ensure the safety of recycled water. Ultraviolet ( UV) is an effective and environmentally friendly technique suitable for the disinfection of recycled water. However, UV disinfection also leads to photoreactivation. This work proposes a combined use of UV irradiation and microwave technique to compensate for the limitations of UV disinfection. RESULTS The process of microwave-induced electrodeless ultraviolet ( MW-EUV) irradiation was utilized to disinfect municipal secondary effluents. A homemade columnar electrodeless UV lamp was used as the source of UV irradiation. Good disinfection results under optimal microwave power at 600 W were obtained. There was no photoreactivation after sufficient irradiation. Cell damage to Escherichia coli by MW-EUV irradiation was investigated by measuring the leakage of K+ and protein from cells and was observed by atomic force microscopy ( AFM). CONCLUSION The MW-EUV irradiation was demonstrated to be a faster and more effective disinfection method than UV or microwave irradiation alone. The irradiated samples met the hygiene standard for the reuse of urban recycling water (Standard Number GB/T 18920-2002) in China. Disinfection depended mainly on UV irradiation, while microwaves were the main cause of bacterial breakup and deformation. This irreversible damage offsets the biological self-healing phenomenon of UV disinfection. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

An electrodeless measurement technique of complex dielectric permittivity of high-K dielectric films is described. The technique is based on a quasi-optic Fabry-Perot resonator and modified for investigation of two-layer dielectric structures -- substrate/K-film. This procedure is destined to be used for providing a simple intermediate control of parameters of high-K films before the following technological process. Regimes of measurements providing the most sensitive conditions for definition of film parameters are considered. The proposed method is tested on two-layer structures with wellknown parameters and is used for characterization of ferroelectric (Ba,Sr)TiO3 films in the millimeter wavelength range (~ 50 GHz). [ABSTRACT FROM AUTHOR]

Microwave discharge electrodeless lamps (MDELs) have been examined for continuous on-site field treatment of contaminated water using solar cells to provide the necessary electrical power. The equipment aimed to decontaminate water in areas impacted by natural disasters such as the extensive earthquake that hit Eastern Japan in 2011. An energy-saving semiconductor microwave generator provided the microwaves to activate the MDELs in a microwave/UVreactor setup operated using a single- mode applicator and an E/H tuner. The herbicide 2,4-dichlorophenoxyacetic acid degraded within a shorter time compared to methylene blue at a defined flow rate through the microwave/UV reactor. Sterilization of natural water contaminated with the bacterial microorganism Escherichia coli was complete within 20 min. [ABSTRACT FROM AUTHOR]

The production of chemicals from lignin by green and sustainable technologies is a promising alternative route to replace fossil fuels. Photooxidation of guaiacol, a model of lignin, to value-added carboxylic acids with microwave discharge electrodeless lamps as light source was investigated in the presence of hydrogen peroxide (H2O2). The coupled UV-vis/microwave irradiation led to a more effective degradation of guaiacol than with conventional photocatalysis. Hydroxyl radicals as active species, confirmed by electron spin resonance spin-trapping, were generated and participated in the oxidation. The effect of different operating conditions such as reaction time, guaiacol concentration, solution pH, as well as oxidant concentration, was evaluated. [ABSTRACT FROM AUTHOR]

Biologically treated leachate usually contains considerable amount of refractory organics and trace concentrations of xenobiotic pollutants. Removal of refractory organics from biologically treated landfill leachate by a novel microwave discharge electrodeless lamp (MDEL) assisted Fenton process was investigated in the present study in comparison to conventional Fenton and ultraviolet Fenton processes. Conventional Fenton and ultraviolet Fenton processes could substantially remove up to 70% of the refractory organics in a membrane bioreactor treated leachate. MDEL assisted Fenton process achieved excellent removal performance of the refractory components, and the effluent chemical oxygen demand concentration was lower than 100 mg L−1. Most organic matters were transformed into smaller compounds with molecular weights less than 1000 Da. Ten different polycyclic aromatic hydrocarbons were detected in the biologically treated leachate, most of which were effectively removed by MDEL-Fenton treatment. MDEL-Fenton process provides powerful capability in degradation of refractory and xenobiotic organic pollutants in landfill leachate and could be adopted as a single-stage polishing process for biologically treated landfill leachate to meet the stringent discharge limit. [ABSTRACT FROM AUTHOR]

Knowledge of the effective radiation spectrum irradiating substrates from microwave powered electrodeless discharge lamps (MEDLs), and the active species that directly oxidize substrates in the photolytic process, is fragmentary and unclear. In this work, we conducted a comparative study using MEDLs made with quartz envelopes (MEDL-quartz) and with borosilicate Pyrex envelopes (MEDL-Pyrex) targeting the degradation of Rhodamine B (RhB) via radical-extinguishing tests. We found that UVC/UVB radiation is essential to generate •OH and H2O2 in the MEDL-quartz system. The degradation of RhB mostly originates from •OH species, which account for a contribution of 53.8%, while the remaining contribution is attributed to oxidation by H2O2 and direct photolysis. This degradation is influenced by several parameters. Acidic and neutral pHs, but not extreme alkaline pH, benefit the degradation. To ensure a high intensity of UVC/UVB, the optimum ratio of the MEDL volume to the aqueous solution volume (VL/VS) is 0.4. Concentrations of 0.15-0.20 mmol/L of RhB are suitable to obtain an effective quantum absorbance in the MEDL-quartz system, showing a high decomposition rate of 5.6 × 10−3 (mmol/L)min−1. Moreover, two other substrates, Reactive Brilliant Red X-3B and Safranine T, were tested and found to be efficiently degraded in the MEDL-quartz system. [ABSTRACT FROM AUTHOR]

This study presents interior microwave discharge electrodeless iodine lamps (IMDEL-I2) that assist the photodegradation of CS2 at room temperature and atmospheric pressure. The investigation examined the photolysis efficiency of CS2, the absolute removal amount (ARA), and the energy yield (EY) under different gas residence times and input powers and also included an analysis of the photodegradation products of CS2. The experimental results indicated that the IMDEL-I2 was capable of emitting ultraviolet (UV) radiation in bands of 206.2, 250-350, and 385-400 nm, and vacuum ultraviolet (VUV) light at 178.3, 180.1, 183, 184.4, and 187.6 nm. The photodegradation rate of CS2 in the IMDEL-I2 system was 93.4%, with ARA of 18.1 mg=s and EYof 82.5 mg=kWh at the gas retention time of 1.98 s, an input power of 796 W, and an initial concentration of 85.6 mg=m³. The final photolysis products of CS2 were identified to be SO2, CO2, CO, and COS in the gaseous phase, and (CS)n, SO42-, and sulfur in the solid phase. [ABSTRACT FROM AUTHOR]

This paper presents a comparative investigation, design and development issues about six different single-stage topologies, applied as electronic ballasts, for electrodeless fluorescent lamps. The ballast is intended to feed a 100 W lamp at 250 kHz, with dimming feature. The proposed topologies use different converters for the power factor correction (PFC) stage: Buck-Boost, SEPIC, Zeta, Cúk, Flyback, and Boost. All of them operate in discontinuous conduction mode. A resonant half-bridge inverter is used as lamp power control (PC) stage. The integration of both stages (PFC and PC) is proposed in this paper. In this way, it is possible to reduce the number of active switches, as well as simplify the required driving and control circuitry. Experimental results demonstrate the feasibility of the proposed dimming technique that achieved around 56% lamp power dimming, from 100 W down to 44 W. The implemented topologies attained high average power factor (>0.98), and low line current average total harmonic distortion (<;15.3%). A comparison among all the proposed topologies in terms of power factor, harmonic distortion, efficiency and number of components is presented. Finally, a comparison between an integrated and a nonintegrated SEPIC half-bridge converter is also performed. [ABSTRACT FROM AUTHOR]

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Highlights: [•] The photolysis of low concentration of H2S malodorous gas. [•] Self-made high frequency discharge electrodeless lamp. [•] Effects of relative humidity and gas environments. [•] Mechanisms for direct and indirect photolysis (ozone and radical generation). [Copyright &y& Elsevier]

Highlights: [•] A method was developed for the determination of metals and metalloids. [•] Analysis of 11 canned and 2 aseptic paper pack tomato paste samples. [•] Calculation of methods’ uncertainty. [•] Validation of a new quality indicator for opened cans. [•] Migration tests depending on mass balance were accomplished. [Copyright &y& Elsevier]

In order to extend the length of the coaxial cable connection between an electrodeless fluorescent lamp and the associated electronic ballast, a new structure for electrodeless lamp systems is proposed in this paper. Impedance matching networks in the structure are analyzed and designed based on the transmission characteristics of coaxial cable. Efficient topologies and formulae for the matching networks are put forward. Experimental results for a 2.65 MHz electrodeless lamp system with up to 25 m of coaxial cable which validate the structure are presented. [ABSTRACT FROM PUBLISHER]

The construction and operating characteristics of a microwave (MW) electrodeless UV lamp are described. Instead of using a MW oven or a MW cavity to excite a plasma discharge in a glass bulb, in this work the optical radiation emitted by the gaseous plasma discharge is produced by the near field of a coaxial cable dipole antenna placed inside the recess of the quartz bulb. Experimental results are reported, which were obtained by applying MW power up to 700 W in continuous wave regime to an Ar–Hg filled cylindrical bulb, and 160 W to a XeBr2filled spherical bulb at 2.45 GHz. The UV emission from a 6 W Ar–Hg lamp is compared with a commercial lamp, demonstrating the advantages of the new method in terms of efficiency. When the lamp is excited at high MW levels, the MW coaxial antenna is cooled using forced air or water flowing into the glass recess. The physical modeling of the electromagnetic field distribution in the near-field region of the antenna and its interaction with the gaseous discharge are in good agreement with experimental results. The article focuses on the advantages of the non-cavity activation method of the UV lamp, taking into account industrial applications. In fact, the coaxial antenna excitation method is characterized by extreme simplicity, due to the absence of resonant metal enclosures. Thus, the ordinary MW cavity can be replaced by a number of independent MW UV emitters, placed inside a reaction vessel of arbitrary size and material. [ABSTRACT FROM PUBLISHER]

Highlights: [•] A novel submerged photocatalytic membrane distillation reactor was developed. [•] Microwave electrodeless lamps were used as the light source. [•] A loose cake layer was formed on the membrane surface at a high TiO2 dose. [•] High quality permeate was obtained from a high-concentration dye wastewater. [ABSTRACT FROM AUTHOR]

The destruction of low concentration of toluene (0-30 ppm) has been studied under the UV/photogenerated O3/MnO2-impregnated granular activated carbon (MnO2-impregnated GAC) process by the combination of self-made high frequency discharge electrodeless lamp (HFDEL) with MnO2-impregnated GAC catalyst. Experimental results showed that the initial toluene concentration can strongly affect the concentration of photogenerated O3 from HFDEL and the efficiency and mass rate of destruction of toluene via HFDEL/MnO2-impregnated GAC system. Active oxygen and hydroxyl radicals generated from HFDEL/MnO2-impregnated GAC system played a key role in the decomposition of toluene process and the intermediates formed by photolysis are more prone to be mineralized by the subsequent MnO2-impregnated GAC catalyst compared to the original toluene, resulting in synergistic mineralization of toluene by HFDEL/MnO2-impregnated GAC system. The role of MnO2-impregnated GAC catalyst is not only to eliminate the residual O3 completely but also to enhance the decomposition and mineralization of toluene. [ABSTRACT FROM AUTHOR]

In order to realize laser frequency stabilization, the global evolution of an analyzer angle on the electrodeless-discharge-vapor-lamp-based excited-state Faraday anomalous dispersion optical filter (LESFADOF) with a single transmission peak operating on the Rb1529 nm (5P-4D) is presented. We find that the transmission of the line center peak at −80° arrives at 14% in a 3 cm length lamp contained natural Rb mixed with 2 torr Xe buffer gas operating at 250°C with 176 MHz radio frequency. When it is used to realize laser frequency stabilization, the LESFADOF at near −80° is appropriate. Whether a single transmission peak or double transmission peaks depend on the rf voltage when two polarizers are crossed. [ABSTRACT FROM AUTHOR]

The intensity of fluorescence spectral lines of Rb atoms in the region of 350-1110 nm is measured in eletrodeless discharge lamp. The population ratio between the excited states is calculated according to the spontaneous transition probabilities with rate equations. At the same time, the population density of energy level is also obtained. The results provide the potential applications of electrodeless discharge lamp in atomic filter and optical frequency reference at higher excited states without a pumping laser. [ABSTRACT FROM AUTHOR]

Highlights: [•] Anatase appeared in the TiO2 film with the mean crystalline size of 24nm. [•] When irradiating with MEDL, the TiO2 film coated reactor could generate ROS in air. [•] TiO2 film under MEDL irradiation was effective in removing H2S in air atmosphere. [Copyright &y& Elsevier]

We report an experimental demonstration of two-dimensional (2D) lensless ghost imaging with true thermal light. An electrodeless discharge lamp with a higher light intensity than the hollow cathode lamp used before is employed as a light source. The main problem encountered by the 2D lensless ghost imaging with true thermal light is that its coherence time is much shorter than the resolution time of the detection system. To overcome this difficulty we derive a method based on the relationship between the true and measured values of the second-order optical intensity correlation, by which means the visibility of the ghost image can be dramatically enhanced. This method would also be suitable for ghost imaging with natural sunlight. [ABSTRACT FROM AUTHOR]

We measure the intensity of fluorescence spectral lines of Cs atoms in an electrodeless discharge lamp from visible light to the near-infrared region of 400–1000 nm. To build an excited state Faraday anomalous dispersion optical filter, the population ratios between the excited states are calculated by rate equations and the spontaneous transition probabilities. The electrodeless discharge lamp with populations in the excited states can be used to realize the frequency stabilization reference for lasers at multiwavelength and the excited state Faraday anomalous dispersion optical filter for submarine communication applications in blue—green wavelengths to simplify the system. [ABSTRACT FROM AUTHOR]

We mainly present the 728 nm laser spectroscopy and Faraday atomic filter of Cs atoms with 650 MHz linewidth and 2.6% transmission based on an electrodeless discharge vapor lamp, compared with Rb 728 nm laser spectroscopy. Accidentally, this remarkably strong Cs 728 nm transition from the 6F7/2 state to the 5D5/2 state is only about 2.5 GHz away from the Rb 728 nm transition of the future potential four-level active optical clock, once laser cooled and trapped from the 7S1/2 state to the 5P1/2 state, as we proposed previously. A Faraday atomic filter stabilized 728 nm laser using a Cs electrodeless discharge vapor lamp with a power of 10mW will provide a frequency reference to evaluate the performance of the potential Rb four-level active optical clock at 728 nm with power less than 1 nW by 2.5 GHz heterodyne measurements. [ABSTRACT FROM AUTHOR]

We mainly report the 728.0 nm transition between 7S1/2 and 5P1/2 laser spectroscopy of an electrodeless discharge Rb vapor lamp, which is the clock transition of a potential four-level active optical clock, once laser cooled and trapped Rb atoms are pumped by 359.2 nm laser. To realize this proposition, we study the linewidth and absorption characteristics of the 728.0 nm laser absorption spectrum of a rubidium electrodeless discharge vapor lamp with varying lamp temperature and rf driving power respectively, measured by an external cavity diode laser in a Littrow configuration. The measured 728.0 nm spectrum of a glass cell filled with Rb and Ar buffer gases in the electrodeless discharge Rb lamp based Faraday filter stabilized laser can be a heterodyne comparison reference for the weak power output of a possible cold Rb four-level active optical clock at 728.0 nm clock transition with laser cooled and trapped atoms. To the best of our knowledge, there has not been any research reported on Rb 728.0 nm laser spectroscopy in detail. [ABSTRACT FROM AUTHOR]