Xenon Arc Research Articles

Scintillation and thermally-stimulated luminescence properties of Tm-doped CaHfO3 crystals

Tm-doped CaHfO3 crystals were synthesized by the floating zone method equipped four xenon arc lamps, and the photoluminescence (PL), scintillation, and thermally-stimulated luminescence (TSL) properties were investigated. The Tm-doped samples exhibited intense sharp emission peaks at around 460 nm due to 4f–4f transitions of Tm3+. The PL and scintillation decay time profiles showed typical decay time constants of 4f–4f transitions of Tm3+. In TSL dose response, the minimum and maximum detection limit of the Tm-doped samples were 10 and 10000 mGy, respectively.

Scintillation and dosimetric properties of Ce-doped MgAl2O4 single crystals

The undoped and Ce-doped MgAl2O4 single crystals were synthesized by the floating zone method equipped with four xenon arc lamps, and the photoluminescence (PL), scintillation, and dosimetric properties were investigated. The Ce-doped crystals showed PL emission peaks at around 420 and 720 nm. The former was ascribed to the 5 d-4f transition of Ce3+ ion, and the latter was ascribed Mg deficiency. The PL decay time profiles of the Ce-doped crystals exhibited the fast decay, and the decay time constants were the typical value of others Ce-doped materials. Thus, the decay time constants were attributed to the 5 d-4f transitions of Ce3+ ion. In addition, optically-stimulated luminescence (OSL) signals could be detected in all the crystals when the stimulation wavelength was 470 nm. The OSL dose response functions showed linearly proportional relationship from 10 to 1000 mGy in all the Ce-doped crystals. The thermally-stimulated luminescence (TSL) glow curves exhibit three peaks due to antisite of Al3+ ion, V center and antisite of Mg2+ ion. All the Ce-doped crystals showed improved TSL intensity and dose response sensitivity compared the undoped crystal. The 0.2 and 1% Ce-doped crystals showed linearly response at the dose range of the 0.1–1000 mGy.

The Influence of Short-Wave and Long-Wave Radiation Spectrum on the Photostability of Sunscreens

Background: Sunscreen products aim to help protect the skin against UV radiation and consequently reduce the risk of early skin ageing and skin cancer. However, it is well known that some sunscreen ingredients are not photostable, but this usually refers to irradiation with UV light. Moreover, it has to be mentioned that a relative cumulative erythema effectiveness compliant light source is used for the in vivo sun protection factor (SPF) testing. Here, UV simulators equipped with a xenon arc lamp use filters such as WG320 and UG11 (thickness 1 mm) to minimize infrared (IR) radiation and wavelength below 300 nm. However, under practical conditions, the sunscreen product is not only exposed to UVA/B light, but also to visible light (VIS) and IR light. In fact, the spectrum of solar radiation is composed of approximately 7% UV, 39% VIS and 54% IR. Aims: To investigate the influence of short-wave and long-wave radiation on the photostability of sunscreens. Methods: Irradiation was performed with the Suntest CPS+ that is considered to closely imitate solar radiation. The filter UG11 (thickness 1 mm), which absorbs much of the VIS and IR light, and the glass filter WG320 (thickness 2 mm), which effectively absorbs radiation of wavelengths less than 300 nm, were used in the Suntest CPS+ both individually and in combination and were inserted between the light source and the samples. The following transmission measurements were carried out with Labsphere’s UV-2000s device. Here, the effectiveness (percentage change of SPF before irradiation to SPF after irradiation) as a measure of the photostability was calculated. Results:As expected after total solar spectrum irradiation, the effectiveness in all tested sunscreens is lower compared to relative cumulative erythema effectiveness light used for in vitro testing of SPF. In the reference sunscreen formula S2 as well as in the two different sunscreen products, especially long-wave radiation (>400 nm) had an effect on photostability, whereas short-wave radiation had only a minor impact. In contrast, in the BASF sun care gel line only short-wave radiation below 300 nm had an effect on photostability, and blocking VIS and IR light had no effect at all. Conclusion:Based on these data, we can conclude that short waves and/or VIS + IR light have an influence on the photostability of sunscreens.

Effects of interfacial modification for vapor phase polymerized PEDOT on glass substrate

Optically transparent and highly conductive poly(3,4-ethylenedioxythiophene) (PEDOT) thin films were grown through vapor phase polymerization on (3-Mercaptopropyl)trimethoxysilane functionalized 3,4-Ethylenedioxythiophene (MPTMS functionalized EDOT) grafted glass substrates. Compared to bare glass, the EDOT grafted surface led to enhancements in both electrical conductivity and adhesion of PEDOT thin films. A quinoid-rich structure with increased crystallinity and a further enhanced conductivity was induced by post-deposition sulfuric acid doping. X-ray diffraction showed different orientations of the PEDOT crystals grown on substrates with and without EDOT grafting. The highest conductivity of 2690 S/cm, with an average optical transmittance of 95.4 % in the visible range, was achieved when PEDOT was vapor phase polymerized on EDOT grafted substrates and doped with 98 % sulfuric acid. Photostability was tested using a xenon arc light source and characterized by attenuated total reflection Fourier-transform infrared spectroscopy, showing that photo-induced degradation is associated with a decrease in CC double bond content.

Mold Resistance of Nano and Micronized Particles-Treated Wood After Artificial Weathering Process

Wood and wood based materials under outdoor conditions may lose their appearance and performance properties by time. Color differences, cracks, rough surface may occur within a few years in unprotected wood. These undesired formations could be avoided by technical applications such as coatings on wooden surfaces by paints and varnish since such coating materials include special additives in their formulations such as UV absorbents, pigments, etc. Novel systems with nano or micronized particles may have superior properties when compared to conventional wood preservatives. In this study, we compared nano-scale, micro-scale and common wood preservatives in treated wood in terms of their effectiveness against mold fungi before and after artificial weathering process. Accelerated weathering tests of the test specimens were performed in a Xenon arc radiation cabinet with water spraying property. Artificially weathered and treated wood specimens were evaluated for resistance to mold fungi according to the ASTM D4445. General mold score results collected before and after artificial weathering process showed that CCA and MCQ-treated specimens had the best performance properties; however, nano zinc oxide-treated wood specimens had the weakest performance against mold fungi.

Numerical Characterization of a High Flux Solar Simulator Using Forward and Inverse Methods

Abstract The numerical characterization of a 10 kWe xenon arc high flux solar simulator is thoroughly presented and performed using two approaches: a forward Monte Carlo ray tracing (MCRT) method and an inverse ray tracing method. Experimental characterization was previously performed for the solar simulator using an indirect flux mapping technique, where the experimental heat flux distribution was obtained at the focal plane and additional 12 planes away from the simulator. For the first numerical characterization method, an in-house MCRT code was used to determine the shape of the xenon arc to best model the simulator. It was determined that an isotropic volumetric source consisting of a hemisphere of 1 mm radius that is attached to a cylinder of 1 mm in radius and 10 mm in length well described the experimental results obtained. The in-house code was then used to generate heat flux maps similar to that obtained experimentally and determine the intensity at the focal plane to be used by the inverse ray tracing method presented for its validation. For the inverse method, intensity interpolation schemes of zeroth and first-order were examined in addition to different solution strategies. It is shown that a first-order interpolation scheme unnecessary complicates the inverse problem, leading to larger errors. In addition, a new approach of constraining the formulated system of equations with an equality constraint that works by eliminating intensity values not tracing back to the ellipsoidal reflector is proposed. This new approach provided intensity values with reduced percentage errors.

Synthesis and scintillation properties of Ce-doped CaZrO3 single crystals

Undoped and Ce-doped CaZrO3 single crystals were synthesized by the floating zone method equipped with four xenon arc lamps, and their optical and scintillation properties were evaluated. The synthesized single crystals show high transmittance at a wavelength longer than 400 nm. The excitation and emission spectra of undoped CaZrO3 single crystal excited by vacuum ultraviolet (VUV) light show emission peaks at around 340 and 600 nm. The X-ray-induced scintillation spectra of Ce-doped CaZrO3 single crystals exhibit a red-shift of the emission peak and concentration quenching with an increase in Ce concentration. The afterglow levels of Ce-doped CaZrO3 are lower than those of Ce-doped CaHfO3 crystals.

Study on the Lightfastness of Ink Based on Visible and Infrared Spectral Analysis

A method based on visible reflection and infrared absorption spectroscopy is proposed to elucidate the colour variation law and mechanism of gravure ink in daylight. Three kinds of gravure spot colour ink, blue, red and cyan, are used for a xenon arc ageing experiment. The spectral reflectance of the samples is collected every 2 hours to analyse the variation in the chromaticity. A polynomial regression model of the colour difference and ageing time is established by the nonlinear least squares method. The coloration composition of the inks is analysed according to the infrared spectrum of the samples. The results show that in a 36-hour experiment with an illumination intensity of 550 W/m2, the lightfastness of the different colours of gravure spot ink is significant. The integrated value of the differential reflectance spectrum analysis shows that blue ink exhibits the largest change in chromaticity, followed by the red and cyan inks. The maximal colour differences of the three samples are 12.37, 4.78 and 1.34, respectively. A third-degree polynomial regression of the colour difference of the ink and ageing time achieves a good fitting result, with regression coefficients of 0.9700, 0.9980, and 0.9646, respectively. The infrared spectroscopy results show that the change in the chromaticity corresponds to changes in the molecular composition and absorption intensity of the pigments. The blue ink, with the largest change in chromaticity, exhibits the largest change in the absorption spectrum. The cyan ink, with inconspicuous changes in the chromaticity, exhibits the smallest change in the absorption spectrum. This research provides a more accurate theoretical basis for an analysis of the colour variation law and mechanism of gravure ink in daylight and provides a reference for lightfastness analysis of textiles, dyes and coatings.

Enzyme-Ligand Interaction Monitored by Synchrotron Radiation Circular Dichroism.

CD spectroscopy is the essential tool to quickly ascertain in the far-UV region the global conformational changes, the secondary structure content, and protein folding and in the near-UV region the local tertiary structure changes probed by the local environment of the aromatic side chains, prosthetic groups (hemes, flavones, carotenoids), the dihedral angle of disulfide bonds, and the ligand chromophore moieties, the latter occurring as a result of protein-ligand binding interaction. Qualitative and quantitative investigations into ligand-binding interactions in both the far- and near-UV regions using CD spectroscopy provide unique and direct information whether induced conformational changes upon ligand binding occur and of what nature that are unattainable with other techniques such as fluorescence, ITC, SPR, and AUC.This chapter provides an overview of how to perform circular dichroism (CD) experiments, detailing methods, hints and tips for successful CD measurements. Descriptions of different experimental designs are discussed using CD to investigate ligand-binding interactions. This includes standard qualitative CD measurements conducted in both single-measurement mode and high-throughput 96-well plate mode, CD titrations, and UV protein denaturation assays with and without ligand.The highly collimated micro-beam available at B23 beamline for synchrotron radiation circular dichroism (SRCD) at Diamond Light Source (DLS) offers many advantages to benchtop instruments. The synchrotron light source is ten times brighter than a standard xenon arc light source of benchtop instruments. The small diameter of the synchrotron beam can be up to 160 times smaller than that of benchtop light beams; this has enabled the use of small aperture cuvette cells and flat capillary tubes reducing substantially the amount of volume sample to be investigated. Methods, hints and tips, and golden rules to measure good quality, artifact-free SRCD and CD data will be described in this chapter in particular for the study of protein-ligand interactions and protein photostability.

Sistem Arus-Votan yang Murah dengan Rintangan Terkawal-Elektronik di bawah Lampu Xenon Arka untuk Pengukuran Kecekapan Sel Suria

Crystalline silicon solar cell efficiency is required in order to accurately determine its performance and evaluate the fabrication process. Extensive automation has led to development of expensive instrumentation. In this study, simple, inexpensive method for measuring solar cell efficiency is reported. A controllable direct current (dc) illumination intensity method based on low power xenon arc lamps was designed and constructed. Low resistance electrical contacts were formed with conventional front surface probes and back surface Au-plated metal plate with vacuum attachment. In order to measure current-voltage (I-V) response, variable resistance approach was chosen. Commercially available, low cost electronic loads power supply is used to precisely vary resistance while measuring cell voltage and current. The resistance is controllably varied from a short circuit to an open circuit position on the I-V curve while measuring cell voltage and current. Plotting current as a function of voltage generates the characteristic solar cell I-V response. Solar cell efficiency measurements were recorded and plotted using LabVIEW program. The light intensity was varied by increasing number of high intensity discharge (HID) 50 W from 1 to four in order to vary respective illumination intensities from 330 to 1200 W/m2 range. The variation in light intensity was aimed at investigation of the electronic loads power supply at low and high currents. This I-V tester has been applied to different types of solar cell to validate its performance. Solar cells measured as part of this study included commercial silicon solar cell and laboratory solar cells with phosphorus oxytrichloride (POCl3) and phosphoric acid (H3PO4) emitter formation. This I-V measurement system for commercial cell exhibited an efficiency of 15.83% and efficiency of 16.2% and 13.3% for solar cells with POCl3 and H3PO emitters.

Comparative Review of Artificial Light Sources for Solar-Thermal Biomass Conversion Research Applications

AbstractIn recent years solar-thermal methods of waste biomass conversion are promptly gaining on attention. For researchers working in areas that suffer from lack of natural solar power, the choice of proper solar simulator for the study is crucial. Solar simulator consist of artificial light source enclosed in proper housing with optical and cooling system, powered by dedicated power supply. Solar simulators are not only granting independence from external conditions, yet provide possibility of research expand due to tuneable output power and emissive spectrum. Over the years, solar simulators were powered by different types of lamps. Throughout the history, the solar simulators were used mainly in photovoltaic and space research, crystal growth industry, and the material testing. For mentioned purposes, the total thermal output power of simulator was playing secondary role in comparison to urgent need of spectral match, irradiance distribution and beam uniformity with terrestrial or extra-terrestrial sunlight. For thermal applications, solar simulators are facing the challenge of providing high output power, described by high radiant heat flux and high heat flux density over the specified target area. In presented paper the comparison of xenon arc, metal halide lams and tungsten halogen for thermal applications has been presented with emphasis on available thermal power, spectral match with natural sunlight and operational issues. The course of decision taken during the selection of artificial light source for construction of laboratory-scale solar pyrolytic reactor is proposed.

Recent improvements of long-path DOAS measurements: impact on accuracy and stability of short-term and automated long-term observations

Abstract. Over the last few decades, differential optical absorption spectroscopy (DOAS) has been used as a common technique to simultaneously measure abundances of a variety of atmospheric trace gases. Exploiting the unique differential absorption cross section of trace-gas molecules, mixing ratios can be derived by measuring the optical density along a defined light path and by applying the Beer–Lambert law. Active long-path (LP-DOAS) instruments can detect trace gases along a light path of a few hundred metres up to 20 km, with sensitivities for mixing ratios down to ppbv and pptv levels, depending on the trace-gas species. To achieve high measurement accuracy and low detection limits, it is crucial to reduce instrumental artefacts that lead to systematic structures in the residual spectra of the analysis. Spectral residual structures can be introduced by most components of a LP-DOAS measurement system, namely by the light source, in the transmission of the measurement signal between the system components or at the level of spectrometer and detector. This article focuses on recent improvements by the first application of a new type of light source and consequent changes to the optical setup to improve measurement accuracy. Most state-of-the-art LP-DOAS instruments are based on fibre optics and use xenon arc lamps or light-emitting diodes (LEDs) as light sources. Here we present the application of a laser-driven light source (LDLS), which significantly improves the measurement quality compared to conventional light sources. In addition, the lifetime of LDLS is about an order of magnitude higher than of typical Xe arc lamps. The small and very stable plasma discharge spot of the LDLS allows the application of a modified fibre configuration. This enables a better light coupling with higher light throughput, higher transmission homogeneity, and a better suppression of light from disturbing wavelength regions. Furthermore, the mode-mixing properties of the optical fibre are enhanced by an improved mechanical treatment. The combined effects lead to spectral residual structures in the range of 5-10×10-5 root mean square (rms; in units of optical density). This represents a reduction of detection limits of typical trace-gas species by a factor of 3–4 compared to previous setups. High temporal stability and reduced operational complexity of this new setup allow the operation of low-maintenance, automated LP-DOAS systems, as demonstrated here by more than 2 years of continuous observations in Antarctica.

Design of Ellipsoid and Spherical Combined Light Source for Uniform Flux and Color Mixing

In this letter, an ellipsoid–spherical combined light source structure is presented for the purpose of uniform flux and color mixing, when considering heat dissipation. To allow more rays couple into spherical chamber while keeping illumination uniformity, algebraic equations to estimate light spot size focused by ellipsoidal reflector are derived and then employed to decide input slot size of the chamber. Then Monte Carlo ray tracing simulation suggests that the most preferable output slot size is between 15% and 30% of the chamber radius when considering both uniformity and available test area. A prototype with a 150-W Xenon arc lamp is fabricated to demonstrate heat distribution for the system, and experiment about uniformity indicates that 89.4% of the test circle radius can reach 2% nonuniformity. Color mixing performance for the system is studied by equipped with three ellipsoidal reflectors to collect rays from different color LEDs, and experiment shows that the maximum root-mean-square error of the spectrum across 90% of output circle radius is 1.4%. Results demonstrate it is a structure with simplified design process and having less dependence with light source type.

Formation and Reactivity of Triplet Vinylnitrenes as a Function of Ring Size

The photoreactivity of cyclic vinyl azides 1 (3-azido-2-methyl-cyclopenten-1-one) and 2 (3-azido-2-methyl-2-cyclohexen-1-one), which have five- and six-membered rings, respectively, was characterized at cryogenic temperature with electron paramagnetic resonance (EPR), IR, and UV spectroscopy. EPR spectroscopy revealed that irradiating (λ > 250 nm) vinyl azides 1 and 2 in 2-methyltetrahydrofuran at 10 K resulted in the corresponding triplet vinylnitrenes 31N (D/hc = 0.611 cm-1 and E/hc = 0.011 cm-1) and 32N (D/hc = 0.607 cm-1 and E/hc = 0.006 cm-1), which are thermally stable at cryogenic temperature. Irradiation of vinyl azides 1 (310 nm light-emitting diode at 12 K) and 2 (xenon arc lamp through a 310-350 nm filter at 8 K) in argon matrices showed that in competition with intersystem crossing to form vinylnitrenes 31N and 32N, vinyl azide 1 formed a small amount of ketenimine 3, whereas vinyl azide 2 formed significant amounts of azirine 7 and ketenimine 6. Thus, vinyl azide 1 undergoes intersystem crossing more efficiently than vinyl azide 2. Similarly, vinylnitrene 31N is much more photoreactive than vinylnitrene 32N. Quantum chemical calculations were used to support the mechanisms for forming vinylnitrenes 31N and 32N and their reactivity.

Model study of the leather degradation by oxidation and hydrolysis

Many objects of culture heritage, comprised of leather, need to receive the right treatment to be restored and to elongate their lifespan. Determination of the degradation degree and even better the type of the degradation is a crucial knowledge for the way of subsequent conservation, exhibition and long-term storage. Collagen based materials are very sensitive to the deterioration and undergo, mainly hydrolysis and oxidation. Namely acid hydrolysis and photooxidation are the most often causes of the disintegration of leather. Contrary to the leather investigation, a few studies dedicated to parchment described some typical features of hydrolysis, oxidation and gelatinization observed applying Attenuated Total Reflection Fourier-Transform Infrared spectroscopy (ATR-FTIR) which is widely used in collagen degradation type research. Except of the collagen secondary structure, followed by IR spectroscopy, we determined the shrinkage temperature of the collagen substrate by Micro Hot Table method (MHT) to reach the degradation level. In this paper, artificially degraded leather samples as a theoretical representative of cultural heritage objects were examined. We discuss the use of both techniques (IR and MHT) as potential methods for fast assessment of oxidation and hydrolysis of vegetable tanned leathers and degradation level. New samples of leather tanned by various vegetable tannins were artificially degraded under controlled conditions. We simulated the photooxidation by means of the Xenon arc lamp exposure, oxidation using the soaking in hydrogen peroxide, acid hydrolysis by the soaking in hydrochloric acid and alkaline hydrolysis using the soaking in natrium hydroxide. ATR-FTIR spectra of reference and tested samples were compared. Oxidation causes increase of the distance between amide I (AI) and amide II (AII) wavenumbers (Δν) above 100 cm−1 and the intensity ratio between AI and AII bands (AI/AII) above 1.6. The AI/AII ratio depends on the type of hydrolysis. The increase above 1.8 proves acid hydrolysis while the decrease under 1 demonstrate alkaline hydrolysis. MHT results are not so obvious. Generally, mainly the hydrolysis causes the decrease of the temperatures. We have found out that knowledge of the whole shrinkage interval is important and provides more appropriate information about the leather disintegration.

Photoluminescence and scintillation properties of Ti-doped CaHfO3 crystals

Ti-doped CaHfO3 crystals were synthesized by the floating zone method equipped with xenon arc lamps, and the photoluminescence (PL) and scintillation properties are investigated. Ti-doped CaHfO3 crystals emit strong blue photons under UV irradiation. The PL and scintillation signals are observed around 410 nm due to the charge transfer related to Ti4+. The PL and scintillation decay time constants are approximately 1 μs, which is relatively shorter than other Ti-doped materials. The scintillation light yield of Ti-doped CaHfO3 crystals is estimated by the pulse height measurement under 137Cs gamma-ray irradiation. The 1.0% Ti-doped sample shows the highest scintillation light yield (3400 photons/MeV) among the present samples.

Acceleration parameters for polycarbonate under blue LED photo-thermal aging conditions

Acceleration parameters have been determined for bisphenol A polycarbonate (PC) exposed to blue light emitting diodes (LED) in a commercial apparatus for testing optical components using absorbance at 360 nm as a proxy for yellowing. The effect of temperature in the range of 90–120 °C gave linear Arrhenius plots with activation energies of 30–48 kJ/mol, depending on the presence of stabilizers. Experiments at irradiances of 5–75 kW/m2 showed good reciprocity with the rate of degradation extrapolating to zero at zero irradiance. Parallel experiments using xenon arc irradiation with UV filters showed that the yellowing was proportional to the sample thickness up to at least 6 mm. The activation energies and thickness dependence are much different from the findings for PC outdoor weathering. Examples are shown for making service life predictions using these acceleration parameters.

Optical improvement for modulating a high flux solar simulator designed for solar thermal and thermochemical research

This study presents the optical improvement of a high flux solar simulator (HFSS) with controllable flux-spot capabilities developed for researching solar thermal and thermochemical processes. The HFSS is comprised of seven 2.5 kWel Xenon arc lamps coupled with ellipsoidal reflectors, a servo-controlled attenuator curtain, and three-axes linear test bench. Different attenuators were designed and tested in order to identify the best curtain geometry to improve the HFSS modulation with the lowest possible radiative losses. The optical design improvement was performed with the aid of TracePro, a Monte Carlo ray-tracing software. From simulation results, radiative peak flux from 1700 to 480 kWm-2 from the focal plane to 300 mm further back was estimated without curtains. By using the attenuators, flux levels from 1570 to 92 kWm-2 at the focal plane were also estimated. An experimental validation was achieved with a single lamp-reflector unit obtaining peak flux distributions from 200±20 kWm-2 to 97±9.7 kWm-2 from the focal plane to 300 mm behind. Flux modulation from 170 to 1.5 kWm-2 was also measured at the focal plane using a servo-controlled curtain from fully-open slats (0°) to partially closed (60°). With this attenuator, introduced as the shutter of the system, the use of several lamps or electronic rectifiers is avoided and the radiative flux is modulated with high resolution in an optomechatronical form.

Impregnation of ZnO onto a Vegetal Activated Carbon from Algerian Olive Waste: A Sustainable Photocatalyst for Degradation of Ethyl Violet Dye

This study is aimed at developing a simple and low-cost method to fabricate ZnO-loaded porous activated carbon (AC-ZnO) prepared from the Algerian olive-waste cakes and utilize it as a photocatalyst for the degradation of Ethyl Violet dye. The synthesized AC-ZnO material was characterized using powder X-ray diffraction, BET surface area measurements, Raman microscopy, thermogravimetric analysis, UV-visible diffuse reflectance spectroscopy, and zeta potential measurements. The degradation efficiency was evaluated with Ethyl Violet (EV) dye in aqueous solution under UV irradiation supplied by a Xenon arc lamp through a Pyrex glass filter (cutoff 280 nm), and the degraded products were identified by using electrospray ionization mass spectroscopy. Additional experiments were carried out under N2 flow and with isopropyl alcohol to examine the role of superoxide and hydroxyl radicals, respectively. The amount of ●OH radical formed on irradiated AC-ZnO was tested with terephthalic acid which can act as a chemical trap for the ●OH radicals. The results from this study indicate that the AC-ZnO is a potential catalyst for the pollutant removal and the ●OH radicals are the key species for the degradation of EV. Further, this study opens up an opportunity to produce cheaper activated carbon support from olive wastes for environmental remediation applications.

Characterization of a New 10 kWe High Flux Solar Simulator Via Indirect Radiation Mapping Technique

This paper presents characterization of a new high flux solar simulator consisting of a 10 kW Xenon arc via indirect heat flux mapping technique for solar thermochemical applications. The method incorporates the use of a heat flux gauge (HFG), single Lambertian target, complementary metal oxide semiconductor (CMOS) camera, and three-axis optical alignment assembly. The grayscale values are correlated to heat flux values for faster optimization and characterization of the radiation source. Unlike previous work in heat flux characterization that rely on two Lambertian targets, this study implements the use of a single target to eliminate possible errors due to interchanging the targets. The current supplied to the simulator was varied within the range of 120–200 A to change the total power and to mimic the fluctuation in sun's irradiance. Several characteristic parameters of the simulator were studied, including the temporal instability and radial nonuniformity (RNU). In addition, a sensitivity analysis was performed on the number of images captured, which showed a threshold value of at least 30 images for essentially accurate results. The results showed that the flux distribution obtained on a 10 × 10 cm2 target had a peak flux of 6990 kWm−2, total power of 3.49 kW, and half width of 6.25 mm. The study concludes with the illustration and use of a new technique, the merging method, that allows characterization of heat flux distributions on larger areas, which is a promising addition to the present heat flux characterization techniques.