Deuterium Lamp Research Articles

Mechanical Property Evolution Model of Polyimide Film by Far Ultraviolet Irradiation

The deuterium lamp was used as simulation source to study the Mechanical property of polyimide film in space far ultraviolet environment, thermo gravimetric and XPS was used to analyze the evolution mechanism of polyimide film in different exposures. It was found that the mechanical properties such as tensile strength and rupture elongation of polyimide film decrease firstly and then exponent increase until to stable. From XPS analysis, it can be found that there were rupture and crosslink of chemical bond in polyimide film. In early stage of far ultraviolet radiation, the rupture of C-N, C=O, C-O, C-C bond is for the decrease of mechanical properties of polyimide film, and as the increase of far ultraviolet exposure, the release of N, and formation of C-N bond is for the increase of mechanical properties of polyimide film.

Research on the irradiance calibration of a VUV dual-grating spectrometer based on synchrotron radiation

A high accuracy instrument calibration is the guarantee of obtaining high precision atmospheric inversion data from a wavelength-dispersive space remote sensing instrument in the orbit. To improve the relative calibration uncertainty of a dual-grating spectrometer in the vacuum-ultraviolet (VUV) band, conventional secondary standard light sources, such as deuterium lamps, used in laboratory calibrating stations are not suited to meet high precision. In this paper we present the calibration of the space instrument based on the Metrology Light Source (MLS) of the Physikalisch-Technische Bundesanstalt (PTB) operated as a primary synchrotron radiation (SR) source with calculable spectral radiant intensity to overcome the limit imposed by secondary transfer standards. For taking into account the difference between the highly linearly polarized SR source and the un-polarized solar radiation, which will be observed by the dual-grating spectrometer in orbit, the calibration was performed at two orientations of the instrument, which are perpendicular to each other with respect to the incident SR. The factors contributing to the uncertainty budget were analyzed. It could be shown that a total relative uncertainty of 2.52% can be achieved, which has greatly improved the calibrating accuracy compared with that obtainable with the conventional standard light source calibrating stations in the VUV spectral range.

Ecological and potential health risk assessment of heavy metals in soils and food crops grown in abandoned urban open waste dumpsite.

This work investigated the levels, ecological and potential human health risk of heavy metals in soils and crop plants of an abandoned open municipal solid waste dumpsite being used for agricultural crop planting at Ugwuaji in Enugu, Nigeria. Samples of soils and plants were collected from the site and heavy metals (Pb, Cr, Cd, Zn, Al and Fe) contents and some soil physicochemical parameters were determined after wet digestion with Nitric acid/perchloric acid mixture. The digested samples and all the supernatants were analyzed for heavy metals using Atomic Absorption Spectrophotometer (Shimadzu AA7000 made in Japan) fitted with deuterium lamp for background correction. The heavy metal concentrations in the soils (mg/kg) ranged from 20.825 to 62.501; 7.25 to 11.806; 54.074 to 275.559; 10.861 to 40.139; 1835.751 to 2225.768; and 7166.724 to 11,601.940 for Pb, Cd, Cr, Fe, Al and Zn respectively. The Cr, Fe, Al, and Zn contents (mg/kg) in the plants samples were within the recommended limits but Cd levels were higher. The ecological and health risk assessments revealed contamination and high human health risk associated to Cd. Apart from Cd, other heavy metals under investigation in the soil posed low ecological risk. The target hazard quotient (THQ) values for Cd in the plants samples were all above one except for for Ocimum gratissimum, indicating that people consuming the plants cultivated in the vicinity of the dumpsite may experience adverse effects due to Cd toxicity.

Characterization of a transient spark micro-discharge in nitrogen using simultaneous two-wavelength diagnostics

A transient spark micro-discharge in nitrogen is investigated between two sharpened electrodes at a pressure of 0.5 bar. The plasma parameters (gas temperature, electron density and reduced electric field) are determined using optical emission spectroscopy (OES) and numerical simulations. The gas temperature of 3500 ± 100 K is determined by the comparison of the measured and simulated rotational distributions of the photoemission spectra of neutral molecular nitrogen N2(C-B,0–0). Both direct and stepwise electron impact excitation are considered in the collision-radiative model. The rate constants for electron impact excitation processes are calculated for different electric field values using the electron velocity distribution function, which is simulated by solving the Boltzmann equation. The applied broadband echelle spectrometer is absolutely calibrated in a spectral range of 200 nm to 800 nm, using two standard light sources, a deuterium lamp and a tungsten ribbon lamp, which are certificated by the Physikalisch-Technische Bundesanstalt (PTB), Germany. With the aid of this absolutely calibrated echelle spectrometer and a microwave atmospheric plasma source operated in a nitrogen flow, the intensified charge-coupled device (ICCD) camera, provided with an in-house made optical arrangement for simultaneous two-wavelength diagnostic is calibrated. The spatial resolution of this diagnostic system under the studied plasma conditions amounts to 13 µm. The accurate examination of the experimental results allows determining the dominant process of electron impact excitation of molecular nitrogen ion from ionic ground state. Applying the chosen excitation model of the nitrogen photoemission, the spatially resolved reduced electric field and the electron density are determined. This is done by using the inverse Abel transformation of the absolute intensities of molecular nitrogen bands N2(C-B,0–0) and (B-X,0–0), which were measured with the calibrated ICCD camera. The measured electric current of the micro-discharge is compared with the calculated one using the measured plasma parameters and a good coincidence is established.

The study on the spectral irradiance responsiveness calibration for UV-VUV solar spectrometer

The monitoring of the solar spectral irradiance has important scientific significance and application value. This paper describes the principle, structure and performance of the UV-VUV solar spectrometer. The calibration principle and the calibration method of the spectral irradiance responsiveness are emphatically discussed, based on synchrotron radiation. The spectral irradiance responsiveness calibration of UV-VUV solar spectrometer in the 165 nm–320 nm spectral range is realized under vacuum environment with PTB transfer standard deuterium lamp as standard source. The results of the calibration are achieved, factors affecting the accuracy of the calibration are analyzed. The synthesized uncertainty of the calibration is 5.1 %.

Spectrophotometric and spectrodensitometric quantification of a new antiviral combination

Accurate, simple, and selective spectrophotometric and spectrodensitometric methods were developed and adopted to quantify velpatasvir (VPS) and sofosbuvir (SFV) concurrently in their pure forms and tablets. The spectrophotometric technique was based on the first derivative of ratio spectra (1DD) technique and developed to determine VPS and SFV simultaneously in table formulation. However, the spectrodensitometric technique was based on thin-layer chromatography (TLC) and densitometry and developed to determine VPS and SFV simultaneously in tablet dosage form. Chromatographic separation was performed using chloroform:methanol 9.5:0.5 (%, v/v) as the mobile phase on glass-coated TLC plates. Detection was achieved using a 265-nm deuterium lamp in absorbance mode. Both analytical methods were validated according to the International Conference on Harmonization (ICH)-Q2B guidelines. The linearity in the range of concentration ranges of 1–50 μg/mL and 5–80 μg/mL were obtained for VPS and SFV, respectively, using 1DD spectrometric method. However, the linearity in the range of 5–50 and 10–70 μg/band for VPS and SFV, respectively, were recorded using TLC–densitometric method. Accuracy was recorded ˃100% for VPS and SFV using both methods. This is the first TLC–densitometry method that can separate and quantify the studied mixture of the drugs. The proposed analytical methods were found to be accurate, precise, selective, robust and sensitive for simultaneous analysis of VPS and SFV in tablet dosage forms.

A Rapid High-Performance Thin-Layer Chromatographic Method to Estimate Quercetin inBenincasa hispida(Thunb.) Cogn. Fruit Pulp

Ayurvedic medicines show great promise due to their holistic approach in the treatment of diseases. However, proper standardization is necessary for their integration into mainstream medicine. One such well-known Ayurvedic trailing herb is Benincasa hispida (Thunb.) Cogn. Its fruit contains numerous secondary metabolites, including quercetin, and is used to treat urinary calculi, blood disease, insanity, epilepsy, jaundice, dyspepsia, fever, and menstrual disorders. The current investigation was undertaken to develop and validate a rapid, sensitive, and reproducible method for quantifying quercetin in the hydroalcoholic extract of B. hispida fruit pulp (HABH). The pre-coated thin-layer chromatography (TLC) aluminum plates with silica gel 60 F254 were used with solvent system comprising toluene–ethyl acetate–formic acid (5:4:0.2, V/V). Determination and quantification were performed by densitometric scanning using a deuterium lamp in the absorbance mode at 262 nm. The validation of precision, accuracy, and reproducibility of the developed high-performance thin-layer chromatographic (HPTLC) method were done as per the International Conference on Harmonization (ICH) guidelines. The mobile phase used for the development of HPTLC/TLC plate yields a distinct band for quercetin (RF = 0.392). The limit of detection and limit of quantification for the method were found to be 20 and 60 ng per band, respectively. The quantified quercetin content was found to be 193.77 ± 2.86 μg in 10 mg of HABH, i.e., 1.94% w/w of HABH. This HPTLC method can be successfully employed for the standardization and quantitative analysis of quercetin in formulation containing B. hispida fruit pulp and it will be helpful in the quality control/assurance of such formulations.

Development and Validation of a High-Performance Thin-Layer Chromatography Method for the Quantification of Rutin in the Fruit Pulp of Benincasa hispida (Thunb.) Cogniaux

The fruits of Benincasa hispida (Thunb.) Cogniaux, a ‘rasayana’ in ‘Ayurveda’, are enriched with several secondary metabolites, and rutin is one of them. Fruits are used for their anabolic, brain tonic, carminative, diuretic, memory enhancer, refrigerant, and vitalizer properties. In view of the fact that herbal medicines and/or products are facing challenges towards global acceptance due to the lack of universally accepted standardization method(s), the aim of the current investigation was to develop and validate a high-performance thin-layer chromatography (HPTLC)—densitometry method for the quantification of rutin in the hydroalcoholic extracts of the fruit pulp of B. hispida (HABH). The separation was achieved in a solvent system consisting of ethyl acetate—formic acid—acetic acid—water at a ratio of 7.2:0.7:0.7:1.4 by volume on a TLC aluminum plate pre-coated with silica gel 60 F254. Quantifications were performed by densitometric scanning under a deuterium lamp at a wavelength of 268 nm in the absorbance mode. The precision, accuracy, and reproducibility of the HPTLC method were validated by the International Conference on Harmonization (ICH) guidelines. The mobile phase employed for HPTLC/TLC resulted in good separation for rutin (RF = 0.357). The limit of detection and limit of quantification of the analysis were found to be 0.1 and 0.3 μg per band, respectively. The rutin concentration in the HABH was found to be 178.28 ± 3.62 μg in 10 mg of the extract. The method developed here is simple, fast, reliable, and sensitive and can be implemented in the analysis and routine quality control of B. hispida formulations containing rutin.

Improving branching fraction calibration methods: The optical to ultraviolet bridge

Herein we report new measurements of key Ar ii branching ratios (BRs) that span the optical to ultraviolet (UV) wavelength region. Our new measurements are the first to use a standard detector, a NIST calibrated Si photodiode, instead of standard sources. The use of a NIST calibrated Si photodiode requires a stable source with sufficient output to yield power measurements with a good signal-to-noise ratio from the NIST calibrated Si photodiode after filters are used to isolate wavelength regions from the source. In this work we used a Hg pen lamp which has good stability, but is a line source instead of a continuum source. The Hg i lines fell near the Ar ii lines of interest and were easy to isolate using filters. A complete calibration of the filter transmission as a function of wavelength is not necessary when a line source is used. The selected Ar ii BRs are the best for testing and/or improving a bridge between an optical calibration based on a tungsten standard lamp and an UV calibration based on a deuterium lamp.

VUV Photodissociation Induced by a Deuterium Lamp in an Ion Trap.

Tandem mass spectrometry represents an important analytical tool to unravel molecular structures and to study the gas-phase behavior of organic molecules. Besides commonly used methods like collision-induced dissociation and electron capture or transfer dissociation, new ultraviolet light-based techniques have the potential to synergistically add to the activation methods. Here, we present a new simple, yet robust, experimental design for polychromatic activation of trapped ions using the 115-160 nm output of a commercially available deuterium lamp. The resulting continuous dissociative excitation with photons of a wide energy range from 7.7 to 10.8 eV is studied for a comprehensive set of analyte classes in both positive and negative ion modes. While being simple, affordable, compact, and of low maintenance, the new setup initiates fragmentation of most precursor ions via their known dissociation pathways. Additionally, some new fragmentation patterns were discovered. Especially, electron loss and electron capture reactions with subsequent fragmentations were observed. For oligonucleotides, peptides, carbohydrates, and organic dyes, in comparison to collision-induced dissociation, a significantly wider fragment distribution was obtained, resulting in an information increase. Since the individual photons carry enough energy to post-ionize the nascent fragments, a permanent vacuum ultraviolet light exposure inside the ion trap potentially goes along with a general increase in detection capability.

Response characterization of EBT-XD radiochromic films in megavoltage photon and electron beams.

The purpose of this study was to investigate the beam quality dependence of the EBT-XD radiochromic films for megavoltage photon and electron beam irradiations by studying their spectral response. Dose, dose rate, and interbatch dependencies were investigated as well. EBT-XD and EBT3 radiochromic films were cut into 5cm2 ×5cm2 pieces, placed between solid water phantoms, and irradiated with 6 and 15MV photon beams, 6 and 10MV flattening filter free photon beams, and 6 and 20MeV electron beams at dose levels between 0.5 and 50Gy. In order to measure the spectral response, the films were illuminated by a deuterium and tungsten-halogen lamp and net absorption was measured in 400-800nm spectral range using a fiber-coupled optical spectrometer. Film samples were then analyzed using a flatbed scanner in the red, green, and blue channel to obtain the optical density of the films. The net absorption spectra of the EBT-XD and EBT3 films showed two absorption bands centered at 635 and 585nm, characteristic of the EBT model. However, for a given dose, the EBT-XD films showed lower net absorbance compared to the EBT3 films. At a given dose level, the net absorption spectra and dose-response curves for EBT-XD films showed only slight variations across various beam qualities. When a calibration curve obtained from a given beam quality is used to measure dose from films irradiated with other beam qualities, the maximum uncertainty in the calculated dose, in ranges 5-40 and 8-50Gy for red and green channels, respectively, were ~3.1% and ~2.4%. The response of the EBT-XD films is dose rate independent but batch dependent. No significant beam quality dependence was observed in EBT-XD films in the dose range up to 50Gy.

Photoluminescence and optical response of ZnO films deposited on silicon and glass substrates

ZnO films are synthesized by RF magnetron sputtering on silicon and glass substrates. Dry plasma is used to etch silicon at 5 min as well as 30 min for the purpose of surface modifications before depositing the films. ZnO films are compared with non etched substrate ones. Surface morphology characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Photoluminescence (PL) of ZnO films increased with increasing etching substrate time. The Photoresponse using Deuterium lamp, Ar laser and He-Cd laser was increased for ZnO films deposited on etched silicon substrate from 0 min to 30 min. No significant change was observed for optical band gap of ZnO films deposited on glass substrate. Films deposited on non etched Si (100) and glass substrates exhibit (002) preferred orientation, but the films with etching time for 5 and 30 min to silicon substrates become polycrystalline with accompanied (100) and (101) orientations as analyzed using x-ray diffraction (XRD). Electrical resistivity increases from 31 × 10−4 Ohm.cm to 218 × 10−4 Ohm.cm with increasing etching time of Si substrate.

Simultaneous high-performance thin-layer chromatographic determination of ondansetron and pantoprazole in their pure forms and spiked human plasma

The therapeutic combination of ondansetron (OND) and pantoprazole (PAN) is widely prescribed for the treatment of many gastrointestinal tract (GIT) disorders. For this reason, a new, simple, very sensitive, accurate and precise HPTLC method was proposed for the determination of OND and PAN in pure forms, normal saline infusion solution, and spiked human plasma. Merck HPTLC aluminum plates pre-coated with silica gel 60 F254 were used as the stationary phase, and the mobile phase consisted of chloroform-methanolethyl acetate (6:2:2 v/v). Using this system resulted in compact , symmetric peaks with the best resolution between peaks. The RF values were 0.50 ± 0.12 for OND and 0.73 ± 0.09 for PAN. The densitometric scanner was set at 302 nm using a deuterium lamp as the source of radiation. The detection and quantification limits were 7.50 and 22.50 ng per spot for OND and 15.81 and 47.42 ng per spot for PAN. The proposed method was successively applied for the analysis of the studied drugs in their pharmaceutical dosage forms, normal saline solution, and spiked human plasma. It gives excellent percent of recovery. Excellent agreement between the proposed method and the reported methods was achieved when the results were matched with respect to accuracy and precision.

Simultaneous multi-element determination in electrothermal atomic-absorption spectrometry with electrothermal atomization

A discussion of the prospects for creating a multi-element atomic absorption (AA) spectrometer leads to the conclusion regarding the expediency of using spectral devices of relatively low resolution. Previous studies showed that the spectrometer with instrumental bandwidth 0.12 nm equipped with a CCD detector could provide the absorption measurements within a wavelength range of 200 – 400 nm using low-noise radiation sources, e.g., deuterium or low current xenon lamps. The rate of data acquisition was sufficient for vapour spectra monitoring during the pulse atomisation in graphite furnace atomizer. The loss in sensitivity due to low resolution is compensated by the possibility of direct determination of several elements in a single liquid or powder sample. Feasibility of multi-element simultaneous AA spectrometry depends on the efficiency of atomization technique and technology of data processing. The concurrent problems are discussed by the example of new calculation algorithm and its application to the analysis of multi-element nitrate and halogen containing reference materials. It is shown that linearization of the calibration curves for about 10 – 15 elements, which are not subject to chemical impacts, can be carried out automatically in a concentration range up to 4 – 5 orders of magnitude with 5 – 10 % deviation from the linearity at the ends of the interval. For the elements forming stable molecular compounds further improvement of the atomization technique is required.

Measurement of the Spectral Irradiance of Deuterium Lamps in the Range of Wavelengths 200–400 nm Using a High-Temperature Black Body Model

A procedure is presented for measurements of the spectral irradiance of deuterium lamps in the wavelength range 200–400 nm with unit reproduction using a high-temperature blackbody model. It is shown that the expanded measurement uncertainty varies between 1.6–6.9%. The measurement results were confirmed with calibrations between VNIIOFI (Russia) and PTB (Germany). The divergence of the results obtained by the two laboratories does not exceed 2%.

Point defects: key issues for II-oxides wide-bandgap semiconductors development

II-oxides wide-bandgap semiconductor, including the beryllium oxide (BeO), magnesium oxide (MgO), zinc oxide (ZnO), have large exciton binding energy (ZnO 60 meV, MgO 80 meV), high optical gain (ZnO 300 cm<sup>–1</sup>) and wide tunable band gap (3.37 eV ZnO, MgO 7.8 eV, BeO 10.6 eV), which are the advantages of achieving low-threshold laser devices in the ultraviolet wavelength. It is also one of the important candidates to replace the traditional gas arc lamp (such as mercury lamp, deuterium lamp, excimer lamp, xenon lamp etc.) as the source of deep ultraviolet and even vacuum ultraviolet. Although, during the past decades, the ZnO-based pn homojunction devices have made great progress in the near-UV electroluminescence, but as the band gap broadens, the acceptor (or donor) ionization energy becomes higher (On the order of hundreds meV), which causing the room temperature equivalent thermal energy (26 meV) cannot make the impurities ionizing effectively. In addition, the self-compensation effect in the doping process further weakens the carrier yield. These above drawbacks have become the bottleneck that hinders II-oxides wide-bandgap semiconductor from achieving ultraviolet laser devices and expanding to shorter wavelengths, and are also a common problem faced by other wide-bandgap semiconductor materials. The regulation of the electrical and luminescent properties of materials often depends on the control of critical defect states. The rich point defects and their combination types make the II-oxides wide-bandgap semiconductors an important platform for studying defect physics. For the identification and characterization of specific point defects, it is expected to discover and further construct shallower defect states, which will provide a basis for the regulation of electrical performance. In this paper, recent research results of II-oxides wide-bandgap semiconductors will be described from three aspects: high-quality epitaxial growth, impurity and point defects, p-type doping and ultraviolet electroluminescence. Through the overview of related research works, II-oxides wide-bandgap semiconductors are clarified as deep ultraviolet light sources materials. Meanwhile, indicates that the key to the regulation of electrical performance in the future lies in the regulation of point defects.

COOMET key comparison COOMET.PR-K1.b.1 spectral irradiance 200 nm to 350 nm. Final report

A bilateral comparison of the spectral irradiance in wavelengths range from 200 nm to 350 nm was carried out between VNIIOFI (Russia) and PTB (Germany) using 30W deuterium lamps as artefacts. The purpose of the comparison is to provide VNIIOFI a link to the results of the key comparison CCPR-K1.b. PTB was a link laboratory, but VNIIOFI served as a pilot. The degree of equivalence (DoE) of VNIIOFI, i.e. the difference of spectral irradiance values measured by VNIIOFI from the key comparison reference value (KCRV), varied from -2.5 % to 1.6 % and was within the standard uncertainty.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Photoluminescence spectra of the Mn2+d-d multiplets transitions of zinc-blende MnTe epitaxial films: laser and deuterium lamp excitation study.

The luminescences of zinc-blende MnTe epitaxial films are respectively excited by a laser and deuterium lamp to study Mn2+d-d multiplets transitions. Besides the inclusion of the band gap, all other excited states related to Mn2+d-d transitions including T14(G4), T24(G4), A14[E4(G4)], T24(D4), E4(D4), and T22(I2) are observed. The shift and broadening of the T14(G4) and T24(G4) lines with increasing temperature are described by the electron-phonon coupling. Step-like energy and intensity shifts for the A14[E4(G4)], T24(D4), E4(D4), and T22(I2) transitions occur in the vicinity of the Néel point, which can be ascribed to the different spin-ordering-induced energy relaxation in ground and excited states of Mn2+d-d multiplets, and these transitions show temperature independence and weak quenching.

Optical properties of SixTiyCzOw composite nanopowder obtained by pulsed plasma chemical method

This paper presents the results of an experimental investigation on the optical properties of the SixTi<yCzOw nanopowders, produced by the pulsed plasma chemical method. Pulsed plasma chemical synthesis is realized on the laboratory stand, including a plasma chemical reactor (6 l) and TEA-500 electron accelerator. The parameters of the electron beam are as follows: 400-450 keV electron energy, 60 ns half-amplitude pulse duration, up to 200 J pulse energy, and 5 cm beam diameter. The spectrum of the diffuse reflection coefficient R(hv) was measured using the AvaSpec-2048-2 (Avantes) spectrometer with the AvaLight-DHS light source (deuterium and halogen-tungsten lamp) and an integrating sphere. The band gap of the obtained composite is 2.03–3.12 eV.

Development of a highly sensitive high-performance thin-layer chromatography method for the screening and simultaneous determination of sofosbuvir, daclatasvir, and ledipasvir in their pure forms and their different pharmaceutical formulations.

The combination of sofosbuvir and daclatasvir or sofosbuvir and ledipasvir is now widely used as an ideal treatment for hepatitis C virus infection. For this purpose, a simple, sensitive, accurate, economic, and precise high-performance thin-layer chromatography was developed and validated for the determination of sofosbuvir, daclatasvir, and ledipasvir in their pure form as well as their different pharmaceutical products. The method used Merck high-performance thin-layer chromatography aluminum plates precoated with silica gel 60 F254 as a stationary phase and mobile phase consisting of methylene chloride/methanol/ethyl acetate/ammonia (25%) (6:1:4:1, v/v/v/v). This system was found to give compact symmetric peaks of sofosbuvir, daclatasvir, and ledipasvir with retardation factors of 0.27 ± 0.01, 0.50 ± 0.007, and 0.68 ± 0.008, respectively. The densitometric scanner was set at 275nm using a deuterium lamp. The calibration curves were linear over the range of 100-3000ng/spot for sofosbuvir, and daclatasvir, and range of 50-3000ng/spot for ledipasvir. The detection limits were 22.5, 31.90, and 15.80 for sofosbuvir, daclatasvir, and ledipasvir. The quantitation limits were 67.50, 95.60, and 47.50 for sofosbuvir, daclatasvir, and ledipasvir. The proposed method was validated according to International Conference on Harmonization (ICH) guidelines and the results were acceptable.