Showing papers by "Thapar University published in 2006"
TL;DR: The purpose of this paper is to review the available information on various attributes of fly ash and explore the possibility of exploiting them for agronomic advantage.
409 citations
TL;DR: In this article, the adsorption and photocatalytic degradation of diazo Direct Yellow 12 (Chrysophenine G), commonly used as a cotton, paper and leather dye has been investigated in aqueous suspension of semiconductor oxide TiO 2 as photocatalyst in a non-concentrating shallow pond slurry type reactor under UV light.
263 citations
TL;DR: In this paper, the authors present an overview of some of the research published on the use of CKD in cement paste/mortar/concrete, and their effect on the CKD properties like compressive strength, tensile strength properties, durability, hydration, setting time, sorptivity, electrical conductivity are presented.
Abstract: Solid waste management is one of the major environmental concerns around the world. Cement kiln dust (KKD), also known as by-pass dust, is a by-product of cement manufacturing. The environmental concerns related to Portland cement production, emission and disposal of CKD is becoming progressively significant. CKD is fine-grained, particulate material chiefly composed of oxidized, anhydrous, micron-sized particles collected from electrostatic precipitators during the high temperature production of clinker. Cement kiln dust so generated is partly reused in cement plant and landfilled. The beneficial uses of CKD are in highway uses, soil stabilization, use in cement mortar/concrete, CLSM, etc. Studies have shown that CKD could be used in making paste/mortar/concrete. This paper presents an overview of some of the research published on the use of CKD in cement paste/mortar/concrete. Effect of CKD on the cement paste/mortar/concrete properties like compressive strength, tensile strength properties (splitting tensile strength, flexural strength and toughness), durability (Freeze–thaw), hydration, setting time, sorptivity, electrical conductivity are presented. Use of CKD in making controlled low-strength materials (CLSM), asphalt concrete, as soil stabilizer, and leachate analysis are also discussed in this paper.
106 citations
TL;DR: In this paper, acoustic and structural properties of calcium borate glasses were studied at ambient temperature using a pulse echo overlap method, and the results indicated that the calcium oxide enters the glass network as a modifier by occupying the interstitial spaces in the network and by increasing the nonbridging oxygen atoms (NBOs).
Abstract: Acoustic and structural properties of x CaO · (1–x ) B2O3 (02 ≤ x ≥ 07) glass system have been studied at ambient temperature The ultrasonic velocity and attenuation for different compositions of calcium borate glasses were measured at 5 MHz at room temperature (303 K) using a pulse echo overlap method The elastic moduli, Debye temperature, Poisson's ratio and other acoustic parameters have been obtained from experimental data Fourier transform infrared spectroscopic analysis has been used to further support the results of acoustic studies The results obtained indicate that the calcium oxide enters the glass network as a modifier by occupying the interstitial spaces in the network and by increasing the nonbridging oxygen atoms (NBOs) (© 2006 WILEY-VCH Verlag GmbH & Co KGaA, Weinheim)
51 citations
TL;DR: In this paper, the entrance-channel effects in the decay of hot and rotating compound nucleus 48Cr*, formed in symmetric 24Mg+24Mg and asymmetric 36Ar+12C reactions, are studied as collective clusterization process, for emissions of both the light particles (LPs) as well as the intermediate mass fragments (IMFs), with in the dynamical clusterdecay model (DCM).
Abstract: The entrance-channel effects in the decay of hot and rotating compound nucleus 48Cr*, formed in symmetric 24Mg+24Mg and asymmetric 36Ar+12C reactions, are studied as collective clusterization process, for emissions of both the light particles (LPs) as well as the intermediate mass fragments (IMFs), with in the dynamical cluster-decay model (DCM). We find that the little differences observed in the decay of equilibrated compound nucleus 48Cr*, formed in the two entrance channels with about the same excitation energy, are not in variance with the Bohr's independence hypothesis. In other words, the present study confirms the entrance-channel independence of the decay of compound nucleus 48Cr* formed due to different target-projectile combinations with similar excitation energies. The collective clusterization process is shown to contain the complete structure of the measured fragment cross sections as well as average total kinetic energies.
47 citations
TL;DR: The results convey that normal ageing in the absence of disease is associated with lesser parasympathetic regulation of heart rate, and the age is an important factor to be considered for prognosis and diagnosis by HRV and BPV.
Abstract: The background to heart rate variability (HRV) and blood pressure variability (BPV), and their determinants and physiological correlates, remain obscure. The impact of age must be taken into account if HRV and BPV are used for predictive purposes in clinical settings. Healthy subjects show wide inter-individual variation in their heart rate behaviour and the factors affecting heart rate dynamics are not well known. This paper has undertaken to evaluate heart rate variability (HRV) and baroreflex sensitivity (BRS) in a random sample of subjects without evidence of heart disease, and to estimate the relation of HRV and BPV behaviour to age. The aim of this study was to analyse the effects of ageing on HRV and BPV for simultaneous recordings of electrocardiograph (ECG) and blood pressure (BP) signals at rest in healthy subjects. We studied eight young (21-34 years old) and eight elderly (68-85 years old) rigorously screened subjects from the Fantasia Database to make the reproducibility and comparability of the results more extensive. Time- and frequency-domain analysis of HRV and BPV was performed on 5-minute ectopic-free recordings. BRS on the heart was estimated by frequency-domain analysis of spontaneous variability of systolic blood pressure (SBP) and RR interval. It has been observed that compared to young the elderly subjects have (i) diminished HRV; (ii) a shift in the power spectral density and median frequency to low frequency side for HRV and to higher frequency side for BPV; and (iii) increased low-frequency alpha index and decreased high-frequency alpha index of BRS with overall alpha index augmented. The results convey that normal ageing in the absence of disease is associated with lesser parasympathetic regulation of heart rate. Thus it is concluded that the age is an important factor to be considered for prognosis and diagnosis by HRV and BPV. For reliable clinical applications, more research needs to be done on a broad spectrum of subjects. In addition, these observations will prove to be useful for dynamic modelling of cardiovascular regulation for testing the authentication of new techniques for analysis purposes.
43 citations
TL;DR: An investigation of the antimicrobial activity of a crude methanol extract of leaves of Callistemon rigidus revealed potential antibacterial activity against a broad spectrum of multidrug-resistant human pathogens.
Abstract: In vitro. investigation of the antimicrobial activity of a crude methanol extract of leaves of Callistemon rigidus. R.Br. (Myrtaceae) revealed potential antibacterial activity against a broad spectrum of multidrug-resistant human pathogens. Agar well diffusion assays of the test extract established significant concentration-dependent antibacterial activity against methicillin-resistant Staphylococcus aureus., vancomycin-intermediate Staphylococcus aureus., vancomycin-resistant Escherichia coli., extended spectrum β.-lactamase-producing E. coli., and multidrug-resistant Pseudomonas. spp.
37 citations
TL;DR: The downregulation observed in mycorrhizal root systems was a component of the molecular cross-talk between symbiotic partners at the origin of differentiation of symbiotic structures.
Abstract: In an attempt to determine whether auxin-regulated plant genes play a role in ectomycorrhizal symbiosis establishment, we screened a Pinus pinaster root cDNA library for auxin-upregulated genes. This allowed the identification of a cDNA, Pp-GH3.16, which encodes a polypeptide sharing extensive homologies with GH3 proteins of different plants. Pp-GH3.16 was specifically upregulated by auxins and was not affected by cytokinin, gibberellin, abscisic acid or ethylene, or by heat shock, water stress or anoxia. Pp-GH3.16 mRNAs were quantified in pine roots inoculated with two ectomycorrhizal fungi, Hebeloma cylindrosporum and Rhizopogon roseolus. Surprisingly, Pp-GH3.16 was downregulated following inoculation with both fungal species. The downregulation was most rapid on establishment of symbiosis with an indole-3-acetic acid (IAA)-overproducing mutant of H. cylindrosporum, which overproduced mycorrhizas characterized by a hypertrophic Hartig net. This indicates that, despite being auxin-inducible, Pp-GH3.16 can be downregulated on establishment of symbiosis with a fungus that releases auxin. By contrast, Pp-GH3.16 was not downregulated in pine root systems inoculated with a nonmycorrhizal mutant of H. cylindrosporum, suggesting that the downregulation we observed in mycorrhizal root systems was a component of the molecular cross-talk between symbiotic partners at the origin of differentiation of symbiotic structures.
37 citations
TL;DR: In this paper, the authors investigated 20 channels at 10Gb/s wavelength division multiplexing (WDM) transmission over 1190 km single mode fiber and dispersion compensating fiber using cascaded inline semiconductor optical amplifier at a span of 70 km for RZ-DPSK (return zero differential phase-shift keying) modulation format by using same channel spacing, i.e. 100 GHz.
37 citations
TL;DR: The influence of various processing parameters on the magnetic properties of strontium ferrite sintered permanent magnets has been studied in this article, where the effect of Fe 2 O 3 /SrO mole ratio, milling time, calcination temperature and sintering temperature on magnetic properties was analyzed.
34 citations
TL;DR: In this article, a colloidal precipitation method with capping agent polyvinylpyrrolidone has been used to synthesize 2.5-nm sized nanoparticles, which have been confirmed by x-ray diffraction and transmission electron microscope studies.
Abstract: ZnS : Mn nanophosphor has been doped with quencher impurity Ni using the colloidal precipitation method with capping agent polyvinylpyrrolidone. The formation of ~2.5 nm sized nanoparticles has been confirmed by x-ray diffraction and transmission electron microscope studies. Energy and time resolved photoluminescence spectra of the synthesized nanophosphors have been studied at room temperature. Photoluminescent spectra for ZnS : Mn, Ni show three peaks at 412 nm, 433 nm and 590 nm corresponding to Ni impurity, sulphide vacancies (Vs) and Mn impurity, respectively. The ZnS : Mn nanophosphor show typical nanosecond lifetimes for defect-related emission and millisecond lifetimes for Mn impurity-related emission. However, the ZnS : Mn, Ni samples showed lifetime shortening, with variation of dopant concentration for defect-related (420 nm) as well as impurity-related emission (590 nm), which is attributed to exchange interaction between Mn2+ and nearest neighbour Ni2+ impurities.
TL;DR: In this article, the authors simulated the 10 × 40 Gbit/s soliton RZ-DPSK WDM signals over 1050 km with spectral efficiency approaching 0.4 bit/s/Hz using semiconductor optical amplifiers (SOAs) as in-line amplifier.
Abstract: We successfully simulated the 10 × 40 Gbit/s soliton RZ-DPSK WDM signals over 1050 km with spectral efficiency approaching 0.4 bit/s/Hz using semiconductor optical amplifiers (SOAs) as in-line amplifier. The cross-gain saturation of SOA can be minimized by settling crosstalk at a lower level by decreasing the differential gain. This decrease in differential gain is in such a way that we get nil power penalty. The maximum transmission distance of 1050 km is possible with differential gain 210 atto cm2 of SOA. The impact of amplification factor, ASE noise power, crosstalk, quality factor and bit error rate for different differential gain has been investigated. It has been shown that with the increase in differential gain of SOA, the transmission distance goes on decreasing. At high value of differential gain 2.5 × 10−16 cm2 for the transmission distance 1050 km, all channels produce inter channel crosstalk with bit error rate greater than 10−6. But for lower differential gain 190 atto cm2, the quality of al...
TL;DR: A simple and efficient design of prototype filters for cosine-modulated filterbanks is proposed, resulting in near perfect reconstruction (NPR) filterbanks, however, higher filter order is required to get NPR solution.
TL;DR: Two connectionist models are proposed based on different learning paradigms, viz., back propagation neural networks (BPNN) and radial basis function Neural networks (RBFNN) to predict the first lactation 305-day milk yield in Karan Fries dairy cattle.
Abstract: In this paper, two connectionist models are proposed based on different learning paradigms, viz., back propagation neural networks (BPNN) and radial basis function neural networks (RBFNN) to predict the first lactation 305-day milk yield (FLMY305) in Karan Fries (KF) dairy cattle. Also, a conventional multiple linear regression (MLR) model is developed for the prediction. In this study, all the models have been developed using a scientifically determined optimum dataset of representative breeding traits of the cattle. The prediction performances of the connectionist models are compared with that of the conventional model. This study shows that the RBFNN model performs relatively better than the MLR model. However, the BPNN model performs more or less in the close vicinity of the conventional MLR model. Hence, it is inferred that the connectionist models have potential as an alternative to the conventional models for predicting FLMY305 in KF cattle.
TL;DR: A series of M-type hexaferrite samples with composition Sr 1− x La x Fe 12 O 19 ( x = 0.00, 0.05, 0.,15 and 0.25) were prepared by standard ceramic technique.
Abstract: A series of M-type hexaferrite samples with composition Sr 1− x La x Fe 12 O 19 ( x = 0.00, 0.05, 0.15 and 0.25) were prepared by standard ceramic technique. AC electrical conductivity measurements were carried out at different frequencies (20 Hz–1 MHz) and at different temperatures. The dielectric constant and dielectric loss tangent were measured in the same range of frequencies. The experimental results indicate that AC electrical conductivity increases on increasing the frequency as well as the temperature, indicating magnetic semiconductor behavior of the samples. The increase in AC electrical conductivity with frequency and temperature has been explained on the basis of Koops Model whereas dielectric constant and dielectric loss tangent has been explained with the Maxwell–Wagner type interfacial polarization in agreement with the Koops phenomenological theory.
TL;DR: A new algorithm for the neural network training in order to have efficient learning and training of the network and the results when tested with the new data have been found to be in good agreement.
TL;DR: The city of Patiala is selected to assess the microbiological safety of fruit chats where the latter is appreciated and consumed by people across the socio economic spectrum.
TL;DR: In this article, the precise control of the liquid crystal droplet morphology in the polymer matrix is essentially required to meet the prerequisites of display device, and experiments have been carried out to investigate and identify the material properties and processing conditions required for the precise controlling of the droplets morphology of the dispersed liquid crystal systems.
Abstract: Liquid crystals dispersed in polymer systems constitute novel class of optical materials. The precise control of the liquid crystal droplet morphology in the polymer matrix is essentially required to meet the prerequisites of display device. Experiments have been carried out to investigate and identify the material properties and processing conditions required for the precise control of the droplet morphology of the dispersed liquid crystal systems. Polarization switching has been studied. Aligned liquid crystal dispersed systems showed higher polarization over unaligned ones.
TL;DR: In this article, the authors have simulated 50 nm up and down wavelength conversion for a non-return to zero differential phase shift keying (NRZ-DPSK) signal using four-wave mixing in an optimized semiconductor optical amplifier (SOA) at 10 Gb/s for the first time.
Abstract: We have simulated 50 nm up and down wavelength conversion for a non-return to zero differential phase shift keying (NRZ-DPSK) signal using four-wave mixing in an optimized semiconductor optical amplifier (SOA) at 10 Gb/s for the first time. For this we optimized the SOA parameters to achieve sufficient quality and enhancement in four-wave mixing effect. This can be done in such a manner that the SOA never saturates and produces maximum four-wave mixing signals with minimum gain fluctuations. The quality of the converted signal is best before the saturation of SOA. Finally, we have numerically simulated cascaded wavelength converters up to 1300 km transmission distance.
TL;DR: In this paper, a ferroelectric liquid-crystalline material (S-(-)-4-(2-n-hexylpropionyloxy)biphenyl-4′-(3-methyl-4-decyloxy)-benzoate) possessing a relatively large spontaneous polarization (P s∼∼ 240 nC cm−2) and containing a lateral methyl group on the aromatic ring of the alkoxy benzoate unit.
Abstract: Dielectric spectroscopy investigations in the frequency range 50 Hz to 1 MHz have been carried out on a new ferroelectric liquid-crystalline material (S-(-)-4-(2-n-hexylpropionyloxy)biphenyl-4′-(3-methyl-4-decyloxy)benzoate) possessing a relatively large spontaneous polarization (P s ∼ 240 nC cm−2) and containing a lateral methyl group on the aromatic ring of the alkoxybenzoate unit. The effect of temperature on the dielectric relaxation modes has been investigated in the SmC* and N* phases. From dielectric dispersion data, relaxation frequency and dielectric strength of all detected relaxation modes have been evaluated and discussed. A new surface-like mode of relaxation frequency ∼11 kHz and dielectric strength 3.8, is seen to appear in the SmC* phase.
TL;DR: In this article, the performance of a double row symmetric hole-entry hybrid journal bearing configuration with 12 holes per row was investigated and the results showed that change in viscosity of lubricant and bearing flexibility affects the bearing design parameter, so the stability of rigid rotor also gets affected.
TL;DR: In this paper, the decay curves of time resolved laser induced photoluminescence, various optical parameters such as Einstein's spontaneous and stimulated coefficients, oscillator strength, integrated cross-section and dipole-moment of ZnO nanobelts have been calculated and reported.
Abstract: Zinc oxide nanobelts have been synthesized by chemical precipitation technique using zinc acetate as starting material. Scanning electron microscopy observations indicate that the lengths of nanobelts are ranging from a few hundreds of micrometers to a few millimeters. X-Ray Diffraction pattern confirms the wurtzite structure. Nitrogen laser is employed here as an excitation source (337.1 nm, 10 ns) for phosphorescence studies. From the decay curves of time resolved laser induced photoluminescence, various optical parameters such as Einstein’s spontaneous and stimulated coefficients, oscillator strength, integrated cross-section and dipole-moment of ZnO nanobelts have been calculated and reported in this paper. Einstein’s spontaneous and stimulated coefficient values obtained from the decay curves indicate the probability of transitions from various traps. Selective excitation of the levels can make ZnO as a best suited laser medium.
TL;DR: In this article, an adaptive controller based on minimum variance, pole placement and linear quadratic techniques is investigated. But the controller is noise sensitive and the actuator voltage changes after each sampling interval.
Abstract: Fixed gain controllers, designed for a nominal system, degrade in performance when the system parameters are perturbed. By making the controller adaptive, ideal performance and granted stability of the closed loop system can be achieved for even a large change in system parameters. In the present study, adaptive controllers based on minimum variance, pole placement and linear quadratic techniques are investigated. The controller based on minimum variance is noise sensitive and the actuator voltage changes sign after each sampling interval. Hence, it is detrimental to the life of piezoelectric actuators. An adaptive controller based on the pole placement technique requires high control effort and gives poor performance at and near the nominal system. But linear quadratic control based adaptive controllers are noise tolerant and are free from the above-mentioned limitations.
TL;DR: In this article, the authors used pulsed-UV laser (nitrogen laser) as the excitation source having pulse width (10ns) and peak power (200kW per pulse).
Abstract: Singly and doubly doped CaS phosphors have been synthesized using the flux method. Excited-state lifetime measurements have been carried out for CaS doped with Mn and quencher impurities (Fe or Co or Ni) having doping concentrations 0.05–0.70% by weight, using pulsed-UV laser (nitrogen laser) as the excitation source having pulse width (10 ns) and peak power (200 kW per pulse). Laser-induced photoluminescence has been observed in CaS-doped phosphors when these phosphors were excited by the pulsed-UV N2 laser radiation. Owing to the downconversion phenomenon, fast photoluminescence emission in the visible region is recorded in microseconds time domain for CaS:Mn, whereas in case of CaS:Mn:Ni, shortest component of lifetime values reduces to nanoseconds time domain.
TL;DR: In this article, free radical scavenging properties and phenolic content of extracts from pickled edible mushroom Agaricus bisporous were evaluated for comparison with raw, unpickled A. Bisporous.
Abstract: Free radical scavenging properties and phenolic content of extracts from pickled edible mushroom Agaricus bisporous were evaluated for comparison with raw, unpickled Agaricus bisporous. Extracts of raw and pickled mushrooms (prepared using a standardized traditional recipe) were compared for their scavenging activities against the 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical and 2,2-azobis -3-ethylbenzthiazoline-6-sulfonic acid (ABTS). The total phenolic content and flavonoid levels were determined using colorimetric methods. Raw, unpickled mushrooms (control) had the strongest scavenging activity and the highest total phenolic content. Both total phenolic content and antioxidants decreased in mushrooms fried in mustard oil for 3, 4, 5 and 6 min, prior to pickling and were significant for mushrooms fried for 5 min. The decrease in total phenolics and antioxidant levels showed a strong negative correlation with increasing frying time. No further decrease in either total phenolic or antioxidant...
TL;DR: In this paper, the machining mechanism and the behavior of certain tool material and work material combinations with respect to penetration rate and tool-wear rate under the influence of different parameters in ultrasonic machining are discussed.
Abstract: The aim of this article is to present the ultrasonic machining of an alumina-based engineering ceramic composite. The machining mechanism and the behavior of certain tool material and work material combinations with respect to penetration rate and tool-wear rate under the influence of different parameters in ultrasonic machining are discussed in this paper. The shocking movement and cutting mechanics of the abrasive particle under the tip of the vibrating tool have been observed using high-speed photographic equipment. The machined surface has been analyzed by using a scanning electron microscope. Surface roughness values were measured and plotted at entry and at exit of the holes for different types and sizes of holes using the surface roughness-measuring instrument "Perthometer."
TL;DR: Observations suggest that unpasteurized or improperly pasteurized milk could be an important source for transmission of E. coli O157:H7 through paneer, and appropriate steps must be taken by government agencies to ensure consumer safety for this dairy product.
Abstract: The growth and survival of Escherichia coli O157:H7 during manufacture and storage of Indian cheese or paneer was investigated. Pasteurized and raw milk that had been inoculated with 104 CFU/mL of E. coli O157:H7 cultures were used for manufacturing paneer samples which were vacuum-packaged and stored at 4°C, 8°C, and 28°C. Survival and growth of E. coli O157:H7 in paneer samples was determined after every 4 h for up to 48 h. Escherichia coli O157:H7 could survive the manufacturing process of paneer and were present at the end of the storage period (at 28°C) in significantly (p < 0.05) greater numbers than the initial inoculum. No significant difference in survival and growth were noticeable in paneer samples manufactured from raw milk. Though refrigeration (4°C or 8°C) effectively inhibited the growth of E. coli O157:H7, this pathogen could survive over a period of 48 h. Our observations suggest that unpasteurized or improperly pasteurized milk could be an important source for transmission of E. coli O15...
TL;DR: In this article, a simple one-dimensional model based on the spectral approach has been presented for grading of the transducers as a means of alleviating the sympathetic pulses, and the signal qualities are evaluated through their Euclidean distances from the applied voltage pulse.
Abstract: Ultrasonic piezoelectric transducers that are employed in various applications are desired to produce a broadband frequency spectrum. However, interference from the sympathetic pulses generated by the transducer limits the duration of the waveform to a very short time. This paper discusses grading of the transducer as a means of alleviating the sympathetic pulses. A simple one-dimensional model based on the spectral approach has been presented. The piezoelectric constant e33 is graded in various manners and their performances are evaluated. The signal qualities are evaluated through their Euclidean distances from the applied voltage pulse. Linearly graded transducers show the best results.
TL;DR: In this article, the authors used different approaches to gain flattening in EDFAs without using additional components; i.e., Gain flattening filter, dispersion shift fiber, periodic gratings, etc.
Abstract: We are using different approaches to gain flattening in EDFAs without using additional components; i.e., gain flattening filter, dispersion shift fiber, periodic gratings, etc. By using gain flatten approach 3, it is possible to achieve the transmission of sixteen channels at 40 Gb/s wavelength division multiplexing (WDM) over a transmission distance of 490 km by single-mode fiber and dispersion-compensating fiber at a span of 70 km with channel spacing of 200 GHz. We observed the bit error rate less than 10-9 and power of received signal more than -5 dBm with NRZ-DPSK format.
TL;DR: In this article, a thermally activated carrier transfer model has been proposed to explain the observed abnormal temperature behavior of the lifetimes in ZnS:Mn, X (X=Fe, Co and Ni) phosphors.
Abstract: Singly and doubly doped ZnS phosphors have been synthesized in the laboratory. The crystal structure has been determined by X-ray diffraction (XRD) studies. Laser-induced photoluminescence has been observed in ZnS-doped phosphors when these were excited by the pulsed UV N 2 laser radiation at liquid nitrogen temperature (77 K). The temperature dependence of lifetimes, trap-depths and decay constant values were investigated for quencher impurities doped ZnS:Mn phosphors. The lifetimes of the orange emission from 4 T 1 – 6 A 1 transition of Mn 2+ ions has been found to decrease at liquid nitrogen temperature. Due to downconversion phenomenon fast phosphorescence /fluorescence emission in the visible region is recorded in milliseconds time domain for ZnS:Mn while in case of ZnS:Mn, X (X=Fe, Co and Ni) phosphors lifetime reduces to nanoseconds time domain. A thermally activated carrier-transfer model has been proposed to explain the observed abnormal temperature behaviour of the lifetimes in ZnS:Mn, X (X=Fe, Co and Ni) phosphors. The high efficiency and fast recombination times observed in doped ZnS phosphors make these materials very attractive for optoelectronic applications.