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The competence of laboratories to perform testing and calibration services for the industry is assured by the ISO/IEC 17025 accreditation. To comply with this standard, it is imperative to ensure metrological traceability through the regular calibration of laboratory equipment at defined schedules, which is time-consuming and demands significant financial resources. The present work applies first-order gray models GM(1,1) using calibration uncertainties to establish an optimized calibration plan that considers different natural characteristics of laboratory activities, thus providing technical support to ensure metrological traceability for a wide range of laboratory tests. A luminous intensity distribution test on LED luminaires and a fire assay method for determining gold were considered. Applying the proposed approach, the outcoming times between calibrations were longer than previously established, reducing 11% of the financial resources for the physical-photometric laboratory and 54% for the chemical laboratory. Therefore, it also increases the availability of calibrated pieces of equipment. Moreover, results showed that this method suits physical and chemical laboratory tests. In conclusion, this methodology could increase the time between calibrations and reduce the financial resources needed while maintaining technical competence or confidence in laboratory results. [ABSTRACT FROM AUTHOR]

Visible light communication (VLC) is a short-range optical wireless communication technology that attempts to achieve communication alongside illumination using existing infrastructure in the band of 430–790 THz. One of the crucial research gaps in VLC is the absence of an experimental evaluation of performance metric parameters like zero frequency (DC) channel gain, received power, bit error rate (BER) and signal-to-noise ratio at divergent wavelengths and luminous intensities for different optical output power levels. The second research gap is the need for an empirical formulation to estimate the BER for a defined data rate and luminous intensity of the light emitting diode (LED). The objective of this experimental work is to bridge the above two research gaps under a realistic illumination setup. The first gap is addressed by analyzing the impact of divergent output optical power levels of LEDs having different values of luminous intensities and wavelength on QoS parameters. The quality of service (QoS) parameters like transmitted optical power, received optical power, DC gain, quality factor and BER are evaluated and analyzed at a data rate of 1.2 Mbps for a maximum distance of 1 m. The work also evaluates the band of forward LED currents in the range of 12–20 mA to achieve a minimum BER of 10−5–10−7 for a maximum distance of 1 m. The second research gap is worked on by proposing a novel mathematical empirical formulation using fifth-order polynomial curve fitting to estimate the bit error rate (BER) by considering factors of luminous intensity and data rate for a maximal distance of 1 m. The empirical formulation is done using Microsoft EXCEL2010® and MATLAB2023®. [ABSTRACT FROM AUTHOR]

The competence of laboratories to perform testing and calibration services for the industry is assured by the ISO/IEC 17025 accreditation. To comply with this standard, it is imperative to ensure metrological traceability through the regular calibration of laboratory equipment at defined schedules, which is time-consuming and demands significant financial resources. The present work applies first-order gray models GM(1,1) using calibration uncertainties to establish an optimized calibration plan that considers different natural characteristics of laboratory activities, thus providing technical support to ensure metrological traceability for a wide range of laboratory tests. A luminous intensity distribution test on LED luminaires and a fire assay method for determining gold were considered. Applying the proposed approach, the outcoming times between calibrations were longer than previously established, reducing 11% of the financial resources for the physical-photometric laboratory and 54% for the chemical laboratory. Therefore, it also increases the availability of calibrated pieces of equipment. Moreover, results showed that this method suits physical and chemical laboratory tests. In conclusion, this methodology could increase the time between calibrations and reduce the financial resources needed while maintaining technical competence or confidence in laboratory results.

The use of CaO:Tb3+ with light green emission on for improvement of both luminescent output and chromatic fidelity of the white light emitted from a light-emitting diode (LED). The CaO:Tb3+ is combined with the yellowemitting phosphor of YAG:Ce3+ to provide sufficient colored spectral proportion for the white light generation, enhancing the color performance. The phosphor combination is utilized for the three most applied LED structures: conformal, in-cup, and remote phosphor structures. The changes in optical properties of these three LEDs are monitored with adjustments in the proportion of CaO:Tb3+. The higher proportion of the green phosphor results in higher scattering efficiency in all structures, offering better color coordination and stronger luminous flux. The color quality scale is somehow reduced when CaO:Tb3+ concentration is more than a certain level. Therefore, depending on the phosphor configuration of the white lightemitting diode (WLED), the concentration of CaO:Tb3+ should be modified to achieve a good color rendition with improved color consistency and luminous properties. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cr3+-doped Sr3Ga2Ge4O14:0.03Cr3+ (SGGO:0.03Cr3+) phosphor was synthesized via a high-temperature solid-phase method. Considering the tunable structure of SGGO, Ga3+ ions in the matrix were substituted with In3+ ions at a certain concentration. The tuned phosphor produced a red-shifted emission spectrum, with its luminescence intensity at 423 K maintained at 63% of that at room temperature; moreover, the internal quantum efficiency increased to 65.60%, and the external quantum efficiency correspondingly increased to 21.94%. On this basis, SGIGO:0.03Cr3+ was encapsulated into a pc-LED, which was applied in non-destructive testing (NDT) experiments, successfully realizing the recognition of water and anhydrous ethanol, proving its potential application in the field of NDT. [ABSTRACT FROM AUTHOR]

The luminous intensity measurements of airport navigational lighting should be performed in accordance with the recommendations of the European Aviation Safety Agency (EASA), which allows for the determination of the possibility of further operation or the need to replace particular lamps. This article presents a device and method for measuring the light main beam of in-pavement airport lamps used on runways and taxiways. During the measuring process in the laboratory dark room, the proposed system automatically prepares reports as heatmaps presenting angular relationships of light distribution. Photometric measurements were made using a BH1750 illuminance sensor, which was compared to a certified Sonopan L-200P luxmeter. The measurement stability of different BH1750 modes was investigated for different airport lamp power source thresholds. Due to distortions in spectral characteristic of BH1750, polynomial corrections were proposed. The functionality of the device was presented for the exemplary assessment of used and refurbished runway in-pavement airport lamps to compare their parameters change. The research results and device implementation were possible through scientific cooperation with the Poznań-Ławica Airport. [ABSTRACT FROM AUTHOR]

This paper focuses on the pain point of the display screen, by reducing the difference of the luminous intensity of RGB chip under the large angle of view, to improve the quality of large view. We introduced an optical optimization layer into the red chip structure to increase the luminous intensity under the large viewing angle, so that the red chip is consistent with blue and green chip. [ABSTRACT FROM AUTHOR]

Camu camu (Myrciaria dubia) is a fruit tree native to the Peruvian Amazon. The first plantations were grown at high densities. However, after 20 years of cultivation, the trees exhibit low flowering and fruiting. The objective of this study was to determine the effect of different thinning densities (3 x 3 m; 6 x 3 m; 4.24 x 4.24 x 6 m, and 6 x 6 m) and fruiting pruning on fruit production in 20-year-old Myrciaria dubia plants. The study evaluated several variables, including the number of flower buds, green and harvested fruits, as well as the mass (g) and equatorial diameter (mm) of the harvested fruits, fruit yield (t ha-1), and light intensity (lux). The best results were observed in Myrciaria dubia plants that were influenced by a thinning density of 6 x 3 m and were not pruned. These plants had the highest number of flower buds, green and harvested fruits, fruit yield, and light intensity, with values of 18805, 7522, 2820.75, 13.3 t ha-1, and 57395.00 lux, respectively. The spacing of 6 x 3 m resulted in favorable conditions for space and light, allowing the productive characteristics of 20-year-old Myrciaria dubia plants to recover. The plants were in a state of ecodormancy due to the suspension of their physiological activities caused by the absence of agronomic management. [ABSTRACT FROM AUTHOR]

WO3:Eu3+ powder was prepared by microemulsion method with cetyltrimethyl ammonium bromide (CTAB) as a surfactant. The prepared WO3:Eu3+ samples were wrapped with SiO2 by a coating method. The WO3:Eu3+@ SiO2 nanocomposites with the core-shell structure were prepared by controlling tetraethyl orthosilicate (TEOS) content (1, 3, 5 and 7%) and water–alcohol ratio (1:3, 1:1.5, 1:1 and 2:1). The structure, morphology and luminescence properties of the prepared WO3:Eu3+@ SiO2 samples were characterized by XRD, SEM, TEM and fluorescence spectra. The results show that the prepared WO3:Eu3+@SiO2 nanocomposites are spherical and granular, and the average particle size is below 100 nm. Under the condition of different TEOS contents, the strongest characteristic peak is located at 554 nm in the green light band at the excitation wavelength of 328 nm. Among the different water–alcohol ratio conditions, the prepared WO3:Eu3+@SiO2 nanocomposite has the strongest luminescence intensity at the water–alcohol ratio of 1:3, and the excitation wavelength is 328 nm. The excitation spectra measured at 612 nm have prominent characteristic peaks at 362, 394, 422, 465 and 499 nm, which correspond to the transition of 7F0→5D4, 7F0→5L6, 7F0→5D3, 7F0→5D2 and 7F0→5D1, respectively. [ABSTRACT FROM AUTHOR]

BaAl1.4Si0.6O3.4N0.6:Eu2+ exhibiting broad excitation and emission bands with intense green emission centred at 510 nm is applied to produce high-performance white-light-emitting diodes (WLEDs). The preparation of the green phosphor utilizes NaNO3 molten salt to attain the purity phase and enhanced luminescence strength boosting the crystalline growth. The influences of BaAl1.4Si0.6O3.4N0.6:Eu2+ on the lighting intensity and color adequacy are investigated at three correlated color temperatures (CCTs) of 3000 K, 4000 K and 5000 K. The lighting output of the WLEDs with high CCTs (4000 – 5000 K) is deemed as enhanced with increasing green-phosphor concentration. The lower CCT shows greater lumen output when using a lower concentration of BaAl1.4Si0.6O3.4N0.6:Eu2+. This tendency also takes place in the case of color uniformity. Conversely, the high concentration of the phosphor is not favourable to the color rendition property of the WLED because of the excessive green-light proportion. It is recommended to keep the concentration of BaAl1.4Si0.6O3.4N0.6:Eu2+ staying below 10 wt% for better color fidelity.

Copyright of Journal of South China Normal University (Natural Science Edition) / Huanan Shifan Daxue Xuebao (Ziran Kexue Ban) is the property of Journal of South China Normal University (Natural Science Edition) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The luminous intensity measurements of airport navigational lighting should be performed in accordance with the recommendations of the European Aviation Safety Agency (EASA), which allows for the determination of the possibility of further operation or the need to replace particular lamps. This article presents a device and method for measuring the light main beam of in-pavement airport lamps used on runways and taxiways. During the measuring process in the laboratory dark room, the proposed system automatically prepares reports as heatmaps presenting angular relationships of light distribution. Photometric measurements were made using a BH1750 illuminance sensor, which was compared to a certified Sonopan L-200P luxmeter. The measurement stability of different BH1750 modes was investigated for different airport lamp power source thresholds. Due to distortions in spectral characteristic of BH1750, polynomial corrections were proposed. The functionality of the device was presented for the exemplary assessment of used and refurbished runway in-pavement airport lamps to compare their parameters change. The research results and device implementation were possible through scientific cooperation with the Poznań-Ławica Airport.

Cr3+-doped Sr3Ga2Ge4O14:0.03Cr3+ (SGGO:0.03Cr3+) phosphor was synthesized via a high-temperature solid-phase method. Considering the tunable structure of SGGO, Ga3+ ions in the matrix were substituted with In3+ ions at a certain concentration. The tuned phosphor produced a red-shifted emission spectrum, with its luminescence intensity at 423 K maintained at 63% of that at room temperature; moreover, the internal quantum efficiency increased to 65.60%, and the external quantum efficiency correspondingly increased to 21.94%. On this basis, SGIGO:0.03Cr3+ was encapsulated into a pc-LED, which was applied in non-destructive testing (NDT) experiments, successfully realizing the recognition of water and anhydrous ethanol, proving its potential application in the field of NDT.

Copyright of Electronic Components & Materials is the property of Electronic Components & Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BaAl1.4Si0.6O3.4N0.6:Eu2+ exhibiting broad excitation and emission bands with intense green emission centred at 510 nm is applied to produce high-performance white-light-emitting diodes (WLEDs). The preparation of the green phosphor utilizes NaNO3 molten salt to attain the purity phase and enhanced luminescence strength boosting the crystalline growth. The influences of BaAl1.4Si0.6O3.4N0.6:Eu2+ on the lighting intensity and color adequacy are investigated at three correlated color temperatures (CCTs) of 3000 K, 4000 K and 5000 K. The lighting output of the WLEDs with high CCTs (4000 - 5000 K) is deemed as enhanced with increasing green-phosphor concentration. The lower CCT shows greater lumen output when using a lower concentration of BaAl1.4Si0.6O3.4N0.6:Eu2+. This tendency also takes place in the case of color uniformity. Conversely, the high concentration of the phosphor is not favourable to the color rendition property of the WLED because of the excessive green-light proportion. It is recommended to keep the concentration of BaAl1.4Si0.6O3.4N0.6:Eu2+ staying below 10 wt% for better color fidelity. [ABSTRACT FROM AUTHOR]

Each pyrotechnic composition has specific sensitivity such as electrostatic discharge (ESD) sensitivity and friction sensitivity (FS), and it also has specific ignition performance, including luminous intensity (LI) and burning rate (BR). These parameters depend on the concentration of pyrotechnic composition ingredients. In this study, Mg/Ba(NO3)2/novolac resin compositions were prepared using different weight ratios (wt.%) of Mg, Ba(NO3)2, and novolac resin. Then, they were investigated by their FS, LI, and BR. The results showed that by increasing Ba(NO3)2 concentration from 33.76 to 84.54 wt.% Ba(NO3)2, the FS increases from 343 N to 65.5 N. However, the LI and BR of this composition increased by increasing Ba(NO3)2 concentration until a 3/1 stoichiometric ratio of Mg/Ba(NO3)2 (from 13086 to 20588 cd (candela) and 11.25 to 13.71 cm/s, respectively for 33.76 to 64.92 wt.% Ba(NO3)2) and decreased afterward (from 20488 to 53.24 cd and 13.71 to 6.45 cm/s, respectively). For Mg/Ba(NO3)2/novolac resin containing 3 to 12 wt.% novolac resin FS increased from 56 to above 360 N. LI and BR decreased from 20057 to 1203 cd and 17.3 to 1.2 cm/s, respectively. The stoichiometric ratio of Mg/Ba(NO3)2 has the highest enthalpy of reaction. Therefore, it can be concluded that it has the highest LI and BR. [ABSTRACT FROM AUTHOR]

Mononuclear octacoordinated ternary Tb(III) complexes involving 1,1,1-trifluoroacteylacetone (tfaa) as main ligand and monodentate or bidentate moieties as secondary ligand, were prepared. Tri-n-octyl phosphine oxide (TOPO) serves as a monodentate ligand with a single donor site (–O), while 1,10-phenanthroline and its derivatives function as bidentate ligands with –N as the donor atoms. The molecular stoichiometry and bonding environment about Tb(III) ion in synthesized samples were confirmed with the help of elemental analysis and the spectroscopic studies of FTIR and proton NMR, respectively. The octacoordinated arrangement around trivalent lanthanides was the outcome of their interactions occurs with oxygen donor sites in T1 and nitrogen sites in T2-T4. The optical investigation was concentrated on examining the absorption, excitation, emission and lifetime spectral data of the complexes. The dominating peak in Tb(III) complexes observed at around 545 nm is accountable for their green color. Thermogravimetric analysis demonstrates the stability of the complexes up to 150–250 °C. The synthesized complexes exhibit significant opto-electronic characteristics and large thermal stability, making them potentially suitable for lighting applications. [Display omitted] • Successfully synthesized Tb(III) ternary complexes employing tfaa as the primary donor and monodentate & bidentate ligands as secondary donors. • Examined the bonding mode of organic ligands with Tb(III) ion through FTIR and proton NMR spectroscopies. • Investigated the optical and redox characteristics of prepared samples. • Maximum luminescence and prolonged radiative deactivation lifetime of Tb(III) with neocuproine, suggesting the effective transfer of energy from sensitizers to emissive centre. [ABSTRACT FROM AUTHOR]

A luminous intensity variation fluorescent probe (Probe 1) for the detection of ferric ion was developed. The quantitative range of Fe3+ content detected was 0–600 μM with the limit of detection at 0.76 μM. Furthermore, after 20 min of Fe3+ addition, the intensity of the luminescence of Probe 1 solution gradually decreased with increase in Fe3+ concentration. In addition, the B and G values of these images showed a linear relationship with Fe3+ concentration (0–500 μM). Probe 1 was successfully used for the rapid determination of Fe3+ concentration in real samples. This study demonstrates that Probe 1 is an excellent tool for the rapid determination of Fe3+ content in real samples using a smart phone without professional equipment. [ABSTRACT FROM AUTHOR]

Optical analysis is critical for evaluating light-emitting diodes (LEDs), and previous studies have been done on the relationship between negative capacitance of LEDs and how to improve luminous efficiency. In this study, optical studies were performed on LEDs of different colors. Luminous intensity is related to frequency. The lower the frequency, the greater the relative luminous intensity, and the luminous intensity basically tends to be saturated. When the relative luminous intensity is within a certain range, the negative capacitance is related to the luminous intensity in a logarithmic relationship. Meanwhile, the relation between negative capacitance and the luminous intensity under different voltages is the same. From the comparison between the luminescence experiment and the previous capacitance characteristics experiment, it can be concluded that the final effect caused by other factors affecting the frequency characteristics of the capacitance is that the composite capacitance exhibits a hysteresis effect, and the lower the frequency, the more obvious the lag. Therefore, the appearance of negative capacitance is not just caused by recombination; there must be other factors. [ABSTRACT FROM AUTHOR]

The great majority of avian species is diurnal and thus endures variation in light intensities, associated with daily, seasonal or lunar cycles. These diurnal birds search their food in light abundant environment and raise their broods in dark cavities. However their visual performance in dim light conditions is largely unknown. Here, we compared light intensity threshold of activity in two groups of passerines, i.e. secondary cavity and non-cavity nesting. For this purpose, different species of secondary cavity and non-cavity nesting passerines were subjected to two phases of trials: in the first trial birds were released in an experimental cage and allowed them to accommodate themselves in darkness for 10 min. In the second trial we turned on the dimmer to a given luminance for 2 min. We found that activity threshold for secondary cavity nesting passerines ranged from 0.05 to 0.2 cdm-2 and non-cavity nesting passerines from 22.00 to 16.00 cdm-2. Our results shed light on the question about potential effect of luminance on visual performance by secondary cavity and non-cavity nesting passerines. [ABSTRACT FROM AUTHOR]

To determine the optimal light intensity and enable plants to cope with various environmental stresses in plant factories, the morphological and photosynthetic characteristics of ginseng seedlings, including the secondary metabolites, were investigated under six light intensities: 25, 50, 75, 100, 125, and 150 μmol m−2 s−1. The shoot length increased with lower light intensity up to 75 μmol m−2 s−1, and the leaf area and specific leaf weight were greatest at 100 and 75 μmol m−2 s−1, respectively. Stomata frequency was higher from 100 μmol m−2 s−1 with higher light intensity, and single stomatal pore length also increased at 150 μmol m−2 s−1. Net photosynthetic rate at light saturation and net photosynthetic rate in growth condition increased sequentially up to 100 μmol m−2 s−1 before rapidly decreasing at 150 μmol m−2 s−1. The dark respiration rate and light compensation point were significantly high at 150 μmol m−2 s−1 only. Fv/Fm and chlorophyll content statistically differed from 63 and 84 days after seedling stand, respectively. Thus, the leaves withered to death with higher light intensity. The ginsenoside content in the roots significantly increased according to the light intensity, and the panaxadiol/panaxatriol (PT) ratio tended to decrease as the PT-type ginsenosides increased further. Taken together, the range of 75–100 μmol m−2 s−1 was found to be beneficial for growth, photosynthetic acclimation response, and total accumulated ginsenosides of ginseng seedlings. [ABSTRACT FROM AUTHOR]

Silicate based phosphors for white LED have many advantages, such as abundant raw materials, low cost, simple synthesis process, composition diversity, adjustable luminescence, and so on. And it is extensively investigated in recent years. Fluxes play an important role in the preparation of silicate phosphor. This paper introduces the use of fluxes in silicate phosphor system. The type and amount of fluxes have some influence on the crystal phase, luminous intensity and morphology of phosphor. The results show that adding different fluxes and the different amount of fluxes can make silicate phosphors form different types of crystal phase. The fluxes cation around the activator ions causes the number of luminescence centers to change, which can change the shape of the emission spectrum and greatly improve the luminous intensity, but excessive fluxes will reduce the luminous intensity of the phosphors. The effect of flux on the surface morphology of phosphor is obvious. Appropriate flux can refine the grain, make the grain size uniform and spheroidize, but excessive flux will make the sample agglomerate. The key on the synthesis of high performance phosphors is to strengthen the study on the mechanism of flux in the preparation of phosphors, and to select the appropriate flux and its dosage. [ABSTRACT FROM AUTHOR]

In this study, color-adjustable Sr 2 YF 7 : xDy3+, and yTb3+ light-emitting phosphors were synthesized through the hydrothermal method. Systematic experiments were performed to determine the optimal doping concentration for Sr 2 YF 7 : xDy3+ phosphor with x = 0.03, resulting in a distinctive light blue emission band attributed to the 4F 9/2 → 6H 15/2 transition. The energy transfer within the double-doped system of Sr 2 YF 7 : Dy3+, yTb3+ (y = 0, 0.06–0.1) was examined by analyzing spectral overlap and reductions in emission lifetimes. Moreover, the mechanism governing this energy transfer phenomenon was investigated. The concentration proportion of Dy3+/Tb3+ in Sr 2 YF 7 phosphors was modulated to achieve color modulation, transitioning from light blue to vibrant green emissions in Sr 2 YF 7 : Dy3+, Tb3+ samples. The intensity of green emission increased with increasing Tb3+ ion concentrations because of the dynamics of energy migration from Dy3+ to Tb3+ levels (4F 9/2 + 7F 6 → 6H 15/2 + 5D 4). Based on calculations using steady-state rate equations, Tb3+ ion doping effectively reduced ionic spacing and consequently amplified the green emission. Furthermore, the results indicated that the luminous intensity ratio of Sr 2 YF 7 : 0.03Dy3+, 0.07 Tb3+ phosphors at 423/303K was notably high at 93.59 %, indicating high thermal stability. Thus, Sr 2 YF 7 phosphors co-doped with Dy3+ and Tb3+ emerge as potential candidates for application in advanced illumination technologies. • The Sr 2 YF 7 : Dy3+, Tb3+ phosphor was prepared through the hydrothermal method. • The lattice structure of Sr 2 YF 7 : Dy3+, Tb3+ phosphor was analyzed, and Dy3+, Tb3+ occupied the Y3+ site in the lattice. • The energy transfer between Dy3+ and Tb3+ ions occurs mainly through the d-d interaction within the SYF phosphor. • The thermal stability of Sr 2 YF 7 : Dy3+, Tb3+ phosphor was analyzed and a green LED device was fabricated. [ABSTRACT FROM AUTHOR]

The technique of subpixel processing of the position of the edge with increased resolution when the object is registered for lumen is proposed. Simulation modeling of the results of subpixel registration is carried out on the example of an ideal registration system. The limitations of the system operation in high and low light conditions are established, the conditions of stable operation of the system are formulated. The behavior of the system in the registration of translucent objects is studied, the value of the standard deviation σsub is estimated for the results of modeling the ideal registration system on the 8-bit CCD-line. The estimated calculations of the standard deviation σsub for the 12-bit CCD-line are carried out.

This paper mainly studies the effect of Zn2+ ion doping on the conversion luminescence performance of NaAISiO4: Er3+, Yb3+ glass-ceramics. Zn2+ doped NaAISiO4:Er3+, Yb3+ up-converted luminescent samples are prepared by high temperature melting method. The heat treatment system, crystal precipitation, glass structure and luminescent properties of the samples are analyzed by synchronous thermal analyzer(DSC). X-ray diffraction (XRD). Fourier infrared spectrometer and fluorescence spectrum analyzer. After the two-step heat treatment of matrix glass; NaAISiO, crystals are precipitated out of the sample. With the gradual increase of Zn2+ ion doping concentration, the crystal integrity of the sample changes. indicating that Zn2+ enters the crystal interior, breaking the symmetry in side the crystal and causing lattice distortion. Under the pumping excitation of the 980 nm laser. green light emission peak appears at 543 nm and red emission peak appears at 668 nm. The results show that the emission intensity of red light at 668 nm increases gradually with the increase of Zn2+ doping concentration, indicating that a certain concentration of Zn2+ doping has a great promotion effect on the enhancement of up-conversion luminescence intensity of the sample. [ABSTRACT FROM AUTHOR]

This study presents the optical design of light guide prisms for automotive tail light applications to obtain the optimum luminous intensity and the illuminance uniformity. The design was achieved using optical design software, SPEOS. By considering the axial luminous intensity and legal requirements, the optimum prism angles of light guides were determined by simulations. After determining the prism angles, the effect of different surface roughness on the luminous intensity and the illuminance uniformity was investigated. The light guides designed by considering data from the simulation were manufactured as prototypes and their photometrical measurements were made. These measurements were compared to the simulation results. It was observed that simulation and prototype results are well in agreement with each other. Furthermore, it was found that as the surface roughness increases both the luminous intensity decreases and the illumination becomes more uniform. [ABSTRACT FROM AUTHOR]

In order to study the variation of rare earth oxides during thermal failure of thermal barrier coatings, Eu2O3-doped YSZ coatings with 0.5 mol%, 1.0 mol% and 1.5 mol% were prepared by explosive spraying. SEM, XRD, EDS and microhardness tester were used to analyze the effect of different rare earth oxide doping content on the morphology, composition and mechanical properties of the coatings. The results showed that with the increase of rare earth oxide doping content, the porosity of the coatings decreased, and the microhardness and fracture toughness increased. When the doping amount of rare earth oxide is 1.0 mol%, the bonding strength and thermal cycle times of the coating are the highest, 33.4 Mpa and 185 times respectively. With the increase of the doping amount of rare earth, the luminous intensity of the sprayed coating increases. After thermal shock test, the luminous intensity of Eu2O3-doped YSZ coatings at 592 and 608 nm decreased to a certain extent. [ABSTRACT FROM AUTHOR]

Anacardium othonianum Rizz. is a native species of the Cerrado with nutritional and phytotherapeutic properties. Studies that characterize the physiological behavior and the photoautotrophism and production of secondary metabolites by this species in vitro are still scarce. In this context, the objective was to induce photoautotrophism and increase the production of secondary metabolites in A. othonianum using increased light intensities. Five photon flux densities—12, 25, 50, 100 and 150 µmol m−2 s−1—were tested in a growth chamber during in vitro culture. The plant material was analyzed after 50 days of cultivation. Higher values for the leaf area, dry weight and gallic acid were observed under 100 µmol m−2 s−1. Beyond this level of irradiance, the luminous stress increased, as evidenced by the intensification of lipid peroxidation and the lower mean potential quantum yield, chloroplastid pigments and biomass. Luminous intensities below 50 µmol m−2 s−1 did not provide a satisfactory energy supply for the accumulation of biomass and secondary metabolites, such as gallic acid, rutin and vitexin. Therefore, varying the photon flux density represents a promising strategy to both promote photoautotrophism and elicit secondary metabolites in A. othonianum. Key message: The morphophysiological characteristics of Anacardium othonianum cultivated in vitro varied considerably as a function of irradiance, its increased phenolic compounds accumulation. [ABSTRACT FROM AUTHOR]

The green phosphor ZnMoO4:Tb3+ and SiO2 coated phosphors SiO2@ZnMoO4:Tb3+ with core-shell structure were prepared by chemical coprecipitating method. The effects of reactan tconcentration, reaction time, mixing method, calcination temperature, calcination time and surfactant types were investigated. The results showed that the luminescence intensity of green phosphors ZnMoO4: Tb3+ was higher than that of those prepared by back drop mixing method. The excitation peak strength of phosphor ZnMoO4:Tb3+ at 383nm and 493nm increased first and then decreased with the increase of Tb3+ ion concentration. The TG-TGA analysis showed that the green phosphors had excellent high-temperature resistance and the maximum thermal decomposition rate was 285℃. When the addition of surfactant PVP was 5%, the fluorescence intensity was increased by 22%, and the fluorescence intensity of SiO2@ZnMoO4:Tb3+ was increased by 25% compared with that of the phosphor ZnMoO4:Tb3+. [ABSTRACT FROM AUTHOR]

The production of bright light, with vivid color, is the primary purpose of signaling, illuminating devices, and fire control purposes. This study, reports on the development of red flame compositions with enhanced performance in terms of luminous intensity, and color quality. The light intensity and the imprint spectra of developed red flame compositions to standard NATO red tracer (R-284 NATO) were measured using digital luxmeter, and UV–Vis. spectrometer. The main giving of this study is that the light intensity of standard NATO red tracer was increased by 72%, the color quality was also improved by 60% (over the red band from 650 to 780 nm). This enhanced spectral performance was achieved by means of deriving the combustion process to maximize the formation of red color emitting species in the combustion flame. Thanks to the optimum ratio of color source to color intensifier using aluminum metal fuel; this approach offered the highest intensity and color quality. Upon combustion, aluminum was found to maximize the formation SrCL (the main reactive red color emitting species) and to minimize the interfering incandescent emission resulted from MgO and SrO. Quantification of active red color emitting species in the combustion flame was conducted using chemical equilibrium thermodynamic code named ICT. The improvement in red flare performance, established the rule that the color intensifier should be in the range from 10 to 15 Wt % of the total composition.