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This study focused on the water quality for drinking of the confluence of the Diyala River with the Tigris River, south of Baghdad. Due to the need to monitor the water quality in this area frequently and continuously, this study was conducted to find the relationship between water quality parameters and spectral bands by analyzing the data of the Landsat-8 satellite image using Geographic Information System software. The main purpose of this research was to develop a model for chemical and physical parameters based on regression analysis. The water quality parameters used in the study were included (Ph, TDS, EC, TH, Ca, Mg, Turbidity, ALK, CL, SO4, HCO3, K, and Na). Samples were collected from the 16 sites at the same time and date that the satellite visited the study region, which was on 5th November 2021. The coordinates of each station were also taken using Global Positioning System (GPS) device. Band ratios had shown their effectiveness in detecting variables when there was an inverse relationship between two spectral responses to the same physical phenomenon. Then the statistical correlation between the observed and measured values of water quality variables obtained from the laboratory test and the reflectivity of the spectral bands for each pixel was used for analysis. The SPSS program was used for finding correlation and regression equations. The positive and strong correlation between water quality parameters and spectral reflectivity were helped to create 13 models for ten stations and six stations for verification purposes. The values of the correlation coefficients for determination with the model's relation ranged between (0.5-0.993), RMSE was ranged between (0.063-4.783), and NSEC was ranged between (0.581-0.993). These models could be used to predict water quality variables at any point in the study area. [ABSTRACT FROM AUTHOR]

A numerical model is developed for calculating the optical properties of amorphous silicon (a-Si:H) thin films from the spectral response of optical transmission of the films. The method includes predicting the envelopes of upper and lower values of the fringes in transmission spectra, and numerically calculating the film thickness and the spectral responses of refractive index, absorption, and extinction coefficient, which are key optical parameters of the thin film. The procedure was employed on various a-Si:H thin films and obtained reliable accuracy in calculated physical and optical parameters above 98% of the values obtained from spectroscopy ellipsometer technique. Further, the optical model results were used to simulate a-Si:H based solar cell using SCAPS-1D and were in close agreement with the experimental results. [ABSTRACT FROM AUTHOR]

The land use and land cover maps available from various satellite images of past few decades provide the various landform features. The images are interpreted by their respective spectral reflectance. Individual geomorphic features, the river, lake, hills, forest, soil reflect electromagnetic ray differently with different wavelengths. The spectra appear differently for different objects of landforms. Group of pixels are uniform with respect to the pixel values in several spectral bands. The characteristics of the electromagnetic radiation, its transmission, absorption and reflection on the earth's surface are used for detection of the objects and classification. Machine learning is an efficient tool to manage the huge volumes of satellite data collected in the form of raster image. The processes of classification of images are done automatically by the classification algorithm by grouping the spectral classes and assigning to the respective landforms on the basis of reflectance property. These form an information class. The aim of the present work is to generate a classified graph on the basis of the spectral signature applied by the classification process of Machine learning. The resultant output is known as spectral response curve. This will help to produce a classified information document of the landform of the land cover raster data. [ABSTRACT FROM AUTHOR]

In 2013 we published an experimental study (Versteegh and Van der Heijden, doi.org/10.1007/s10162-013-0393-0) that introduced a traveling-wave perspective of cochlear nonlinearity, the so-called spatial buildup of compression and suppression. We recorded basilar membrane (BM) motion in the base of the gerbil cochlea, and obtained experimental evidence for the spatial buildup by independently varying the frequencies of the suppressor and the probe. The study concluded that the nonlinear response at any point in the cochlea can only be properly understood in terms of a spatial buildup of compression. Traveling waves start out as linear responses to the stapes drive and gradually accumulate compressive nonlinearity after entering their peak region, ∼½ octave short of their best place. Likewise, the nonlinear effects of intensity on vibration phase can only be understood in terms of local changes in propagation velocity of the wave. Once viewed through this lens, a large body of published data on the effects of compression and suppression, often featuring complex patterns and seemingly contradicting trends, was shown to fit in a unifying framework. Despite the emphasis on spatial buildup, the data underling the 2013 study were obtained from single BM locations, due to the need for reflective microbeads with laser Doppler vibrometry. The spatial aspect was only explored by proxy, i.e., by varying the stimulus frequency and exploiting the tonotopy of the cochlear response ("scaling"). Optical coherence tomography (OCT) vibrometry has liberated us from this limitation, and in the current work we actually traced the spatial buildup of compression. In the BM and OHC region of the 13-24-kHz region of the gerbil cochlea, we recorded responses to equal-amplitude tone pairs centered at 15 kHz, spaced by 20 Hz. The resulting beating pattern affords a dynamic way of obtaining I/O curves. Spectral analysis of the responses yielded an accurate quantitative description of the compressive growth. We observed that the amount of compression (the difference in gain between the peak and dip episodes of the beat) increased gradually and systematically along the course of the slowly propagating wave, which confirms the spatial buildup claimed in our 2013 study. With increasing instantaneous intensity, the spatial rate of compression increased systematically over the nonlinear region. Overall, the conclusions of the 2013 study were confirmed, emphasizing the tight relation between cochlear compression and the wave character of cochlear vibrations. [ABSTRACT FROM AUTHOR]

In this work, the characterization and properties of photodetectors based on cerium oxide mixed in proportions with gold and the effect of silver in the form of a compound were verified. The materials were prepared using a pulsed laser as a colloidal liquid in deionised and distilled water. The electrochemical etching method (P-type) and spin-coating method were used to deposit metal oxides on porous silicon slides in the form of thin films, which were then used to examine the properties of the photodetector in both the light and the dark with the applied forward voltage ranging from (0.1 to 5) and the intensity of illumination from the source (9.8 mW/cm2). The properties of (I-V) show that the gold and cerium oxide thin film deposited on the (p-type) porous silicon chip has a lower efficiency compared to the sample when adding silver NPs deposited on the p-types has higher efficiency; the manufactured photodetector of (Au-CeO2), (Au-Ag-CeO2) shows improved values of spectral response, quantum efficiency, respectively and a spectral directivity at the wavelength (550 nm) and spectral response in Ultraviolet region for (Au-Ag-CeO2) NPs. [ABSTRACT FROM AUTHOR]

In coastal engineering, one of the main problem experienced by the large port with ship operation is moored ship motion due to the exterior long wave activities. To control the wave induced vessel motion inside port, accurate estimation of spectral wave response behavior in the port due to the multidirectional incident waves is essential. For this, a numerical model has been formulated using the finite element method with governing equation as mild slope equation. The model incorporates different boundary conditions: permeable breakwater, fully or partially absorbing wall boundary conditions. The numerical model is verified and validated with existing experimental and analytical approximations. The numerical scheme has been applied on Paradip port, Odissa, India and the variations on wave spectrum due to the incident wave in the port basin with and without including breakwater has been investigated. Based on simulation analysis, measures to attenuate the water wave oscillations inside port basin under the resonance state are discussed. [ABSTRACT FROM AUTHOR]

Significant interest has been gained during the last decade in the market for flexible optoelectronic technologies for wearable applications. Moreover, broad spectral response photodetectors are also needed for industrial applications such as chemical / biological sensing, image, large spectral switches and environmental monitoring. In this research, a novel SnS film based photodetector withbhigh performance and low cost was developed onto a flexible substrate polyethylene terephthalate (PET). The SnS nanostructured thin film was deposited using a Chemical Bath Deposition (CBD) method. The photo-detector exhibited a high sensitivity to a wide range of spectral response (UV-Vis-NIR); the sensitivity values of the device for wavelengths of 380, 530, 750 and 850 nm were found to be 107, 88, 174 and 216, respectively. Furthermore, the photoresponse properties were studied by illumination (850 nm) at various bias voltages and power densities of light. Under 850 nm illumination, the photodetector demonstrated a fast response time; the rise time and decay time were 0.17 and 0.052 sec, respectively. In these ranges, the present SnS photodetector is a competitive and promising device, as well as its non-toxic character and low cost. [ABSTRACT FROM AUTHOR]

The design standard update that has been issued by BSN from SNI 1726-2012 to SNI 1726-2019 gives some influence on the calculation of earthquake-resistant building design. The influence given includes internal forces, strength, and resistance. This study was conducted to evaluate the effect of updating code for building design planning on the effect of the base reaction that occurs. The research was conducted using an analytical method with reference to as-build drawings, the results of a land survey in the field, and some of the latest regulations regarding the planning of earthquake-resistant buildings in Indonesia. The analysis was carried out in a low-rise building located in Cupuwatu, Yogyakarta. Structural modelling is modelled with a 3D frame by accepting earthquake loads which are modelled statically and dynamically using a response spectrum. The difference from SNI 1726-2012 to SNI 1726-2019 case study in Cupuwatu, Yogyakarta does not give too significant difference to the calculation of output in the form of base reaction, although there are differences in the value of the response coefficient spectral acceleration parameter in the short period and the response spectral acceleration parameter in the one second period. and long-period transition periods. The difference that occurs is 0.07% in the x direction and 0.1% in the y direction in the intact section and 0.06% in the x direction and 0.13% in the y direction in the cracked section. [ABSTRACT FROM AUTHOR]

The time-history analysis is an important approach in the seismic-resistant design of structures, especially in the increasing use of performance-based seismic designs and seismic protection systems exhibiting nonlinear responses. This method requires input acceleration time-histories that match the seismic characteristics of the site and satisfy the application requirements specified in the design code. This paper focuses on the procedure of selection and scaling artificial accelerograms and natural accelerograms to meet the requirements of Vietnamese code TCVN 9386-2012. The determination of the horizontal elastic response spectra, the application requirements, and the matching criteria specified in the code are first outlined. A proposed procedure of selection and calibration of the time-history accelerations is presented in detail. A typical example is conducted to select and scale a set of accelerograms for a specific seismic region in Vietnam to illustrate the proposed method. The concordance of the calibrated accelerations is validated by matching the response spectral of considered acceleration and the target spectrum and comparing seismic responses between the modal spectral analysis and time-history analysis of two typical linear and nonlinear structures. The results show the high reliability of the proposed procedure and great efficiency in matching the acceleration. [ABSTRACT FROM AUTHOR]

The main objective of this research is to study the emergence of a false urban class in an uninhabited area as a result of the closeness of the spectral response between the dry soil class and the urban class and to study the effect of the presence of wet soil due to rainfall in increasing the ability to reduce the emergence of the false urban class. The study area is chosen to be a specific area located within Mahmudiyah city, south of the capital, Baghdad, Iraq, where the study covers the period from 1986 to 2021 with a five-year interval between every two successive scenes. The Landsat satellites scenes are used in this research, the ENVI and Quantum GIS programs are used to analyze the data. The spring season, which represents the end of the rainy season, was chosen to study the region to obtain the best conditions to reduce and curb the class of false urban to include the period from February 22 to March 25 to achieve the best separation ratio between the urban and soil classes. The classes that make up the land cover were diagnosed through field visits to the study area, which included all the existing classes. The maximum probability classifier was used to classify the land cover of study the area, the false urban class appeared during the years of study, and it was found that the proportion of the false urban class is in inverse relation with the environmental factors, especially its relationship to the amount of rain. [ABSTRACT FROM AUTHOR]

The present work analyses the fundamental transport property of photogenerated carriers named low field mobility for Al0.5Ga0.5N/AlN/Sapphire-based MSM detector using five conventional mobility models. Using Atlas- Silvaco TCAD simulator, appropriate mobility models for differently doped structures were investigated for the least dark current density and improved photocurrent. For each doping case, low electric field mobility models have been compared for I-V characteristics, conduction current density, recombination rate, velocity and mobility of charge carriers. Since there are uncertainties for the most fundamental transport property like field-dependant mobility, therefore more study is required to model mobility for high performance of Wide Band Gap materials. In this work, the mobilities of carriers (mup and mun values) are not specified manually in the Silvaco simulation program however mobility model has been defined. The present work analyses various mobility models on dark current density, photocurrent, mobility and velocity of charge carriers in a photo-absorbent layer. Earlier experimental and theoretical studies have proved that variation in dark current density is greatly affected by doping concentration, structural dimension parameters and optical and electrical properties of detector's materials. The main objective of the present work is selecting the suitable mobility model to get high Conduction current density in light to Conduction current density in dark ratio for each doping case. We also found that selection of models has a significant impact on spectral response. This simulation work could help align theoretical performance with experimental data and utilising AlGaN MSM detectors in modern UV detection and low noise applications. [ABSTRACT FROM AUTHOR]

We investigate the ability of using high-resolution position-sensitive pixel detector and standard non-scanning beams of low-energy protons in air as a flexible tool and simplified technique for density-sensitivity imaging of thin samples. Proton radiography can provide high contrast and low radiation dose delivered to the inspected sample. Density-sensitive contrast response can be provided by a single proton per imaging pixel. For this purpose, we use the silicon semiconductor high-resolution pixel detector Timepix3 to evaluate particle radiography of thin samples with monoenergetic low-energy proton beams from the Tandetron light-ion accelerator. Measurements were performed with various well-defined thin samples. A proton micro beam was used to test and evaluate the technique. Spatial information of the samples is provided by the imaging detector. Density-sensitive contrast is obtained from the measurement of small differences in the deposited energy of transmitted protons across the sample. The transmitted protons are detected with high spatial resolution in the pixel detector. The single particle tracks registered in the detector are analysed by detailed pattern recognition algorithms. Various of these track parameters of spectral response are used for imaging contrast. Resulting proton radiographies for various well-defined thin samples are presented. [ABSTRACT FROM AUTHOR]

We perform broadband cavity ring-down spectroscopy (CRDS) relying on the near-infrared frequency comb as the excitation source and a time-resolved mechanical Fourier transform spectrometer as detection device. The many decays corresponding to each spectral element are recorded simultaneously and sorted after Fourier transformation to yield the CRDS spectrum of CO in Ar contained in a 20'000-finesse cavity. [ABSTRACT FROM AUTHOR]

We have employed VEPP-4 synchrotron radiation to measure CCD detector absolute responsivity in vacuum ultraviolet (115-310 nm) spectral range. The detector is designed in the form of a stainless steel enclosure containing a backside-illuminated CCD to protect the CCD from contamination. The entrance window of the enclosure is a round MgF2 spectral filter transparent for ultraviolet radiation with wavelengths longer than 112 nm. The measurements were carried out at Kosmos Metrological Station at the operating temperature of -100°C on the sensitive surface of the CCD. We utilized SPD calibrated silicon photodiode with 1 cm2 sensitive area and a known spectral sensitivity profile as a reference detector. The resultant measurements show a clear CCD responsivity dip near 280 nm, and a great potential to improve the CCD responsivity values using specially designed anti-reflection coatings. [ABSTRACT FROM AUTHOR]

SKIF is a synchrotron facility to be commissioned in 2024. One of the six beamlines planned to be built in the first phase is the "Electronic Structure" beamline. Now three branch lines are funded, which will host the endstations for Near Ambient Pressure X-Ray Photoelectron Spectroscopy (NAP XPS), Spin-Angle Resolved Photo-Emission Spectroscopy (Spin-ARPES), and Reflectometry and Metrology. The current work presents the conceptual design of the "Electronic Structure" beamline. The NAP XPS endstation will enable in situ and operando studies of a wide range of catalytic systems and in situ studies of regularities of deactivation/poisoning processes for catalytic systems depending on different conditions and of innovative functional materials. Another important technique that will be realized on the beamline (another branch line) involves the Spin-Angle Resolved Photo-Emission Spectroscopy (Spin-ARPES) endstation, which will enable study of the electronic and spin structure of solids for applications in nanoelectronics and spintronics. The third endstation, Reflectometry and Metrology (the third branch line), will be used for certification of spectral optical elements, focusing elements, and X-ray detectors. For absolute calibration of the spectral sensitivity of detectors, reference detector techniques will be implemented. Both a secondary reference detector (silicon photodiode) and a primary one (HTSC superconducting bolometer) will be used as a reference one. [ABSTRACT FROM AUTHOR]

The topic of the work is laser power converters (LPCs) for wavelength range of λ=1 – 1.1 µm based on metamorphic InGaAs heterostructures. Variation of the indium concentration "x" in the InxGa1-xAs active area from 0.23 to 0.18 and the use of a distributed Bragg reflector have been investigated. As a result of the voltage increase (due to the minimum concentration of indium in a LPC with indium concentration of about 18% in the active region), the following record efficiency (for such a type of LPC) for monochromatic light conversion has been achieved: about 52% at 1.06 µm and 55% at 1.02 µm. Moreover, the use of a Bragg reflector has allowed stabilizing high spectral response at the InGaAs absorption edge (x=0.18), and demonstrating more than 47% efficiency at a real operating temperature range (higher than +50°C) at 1.06 µm. [ABSTRACT FROM AUTHOR]

The photocurrent generation profiles in a multi-junction solar cell under concentrated sunlight originated from the Fresnel Lens are investigated both theoretically and experimentally. The design parameters for the FL-SC couple were determined, at which the local current-limiting effect from the Ge subcell had been either appeared or disappeared. Different FLs had been considered, and their refractive profiles were optimized for concentrating the light effectively in the full wavelength range (300-1900 nm, a F L 300 1900 ) and in the shortened one (300-950 nm, a F L 300 950 ). It was found that when designing a F L 300 1900 that had focused the light within the full spectral sensitivity range of the GaInP/GaInAs/Ge SC, the current limitation from the Ge subcell could be overcome if a distance between the FL and SC is equal to design one or increased. The conditions for the effective use of a F L 300 950 ) tailored for the enhanced light concentration for the GaInP top and the GaInAs middle subcells had been searching for. [ABSTRACT FROM AUTHOR]

Have been prepared silver nanoparticles (Ag NPs) as colloidal in water by pulsed laser ablation (PLA) method at optimum pulses energy. The (Ag NPs) were deposited over the Silicon solar cell surface using a spraying coating, and then the coated Si-surface was irradiated by successive overlapping pulses at optimum energy. The spectrum (190-1100 nm) was done to study the optical properties of Ag colloidal solution and its spectra exhibit the characteristic absorption bands with a peak located around the typical value for Ag NPs. Surface morphology of the enhanced Silicon solar cell was examined prior and next laser heating processes. Also, the measurements and calculations showed that the short circuit current Jsc, the overall efficiency ƞ and spectral response Rλ enhanced after these processes above the silicon surface of the solar cell. The relative increase in Jsc was (12.6%) owing to the plasmonic absorption for the incident light that trapped via the Ag NPs forward scattering and owing to the localized surface plasmons excitation in the (Ag NPs) embedded in the Si layer by the laser heating to the Si solar cell surface and the shock wave induced by laser pulses. [ABSTRACT FROM AUTHOR]

In this study, the relationship between the bare soil temperature with respect to its salinity is presented, the bare soil feature is considered only by eliminating all other land features by classifying the site location by using the support vector machine algorithm, in the same time the salinity index that calculated from the spectral response from the satellite bands is calibrated using empirical salinity value calculated from field soil samples. A 2D probability density function is used to analyze the relationship between the temperature rising from the minimum temperature (from the sunrise time) due to the solar radiation duration tell the time of the satellite capturing the scene image and the calibrated salinity index is presented. The study shows a direct relationship between the soil salinity and the temperature rising. [ABSTRACT FROM AUTHOR]

We present a numerical based approach to design a new 2-D hollow core photonic crystal (2-D HCPC) structure of hexagonal lattice arrangement with circular air holes on an Indium Tin Oxide (ITO) slab. We used this structure as an anti-reflective coating (ARC) layer on top of a multi-junction (GaP/InP/Si) solar cell. Apart from the ARC layer a GaAs PhC as back reflector (BR) is used in the MJSC structure. A unique approach by blending light trapping structures to enhance solar cell effciency and light harvesting capabilities for wavelength beyond 750 nm is the goal of the present work. Under AM1.5G condition, the simulation results of the 2-D HC-PC structure as an absorption layer when incorporated on the MJSC structure led to an improvement of 6.38% in cell effciency over the previously reported by the conventional/non-photonic MJSC structure. The absorption spectral response using the 2-D HCPC pattern on ITO as ARC on the MJSC is achieved beyond 1000 nm. An optimization study is also carried out by using InAs as core of the 2-D HCPC structure which resulted to an enhancement of cell effciency by 9.34% as compared to the conventional/non-photonic MJSC structure. [ABSTRACT FROM AUTHOR]

In this work, the susceptibility to abrasion of several CPV optical materials, namely glass, glass with anti-reflective treatment, PMMA, and polycarbonate has been investigated. This abrasion simulates the potential effect of a cleaning procedure of photovoltaic modules in the field. To this aim 200 linear passes with a Nylon brush have been performed on the optical samples, and their response to abrasion has been compared. Besides, the presence of soiling has been included in the abrasion test, simulating real conditions encountered by the cleaning procedures in the field. In this respect, two types of soiling, i. e. Aramco Test Dust and silica, deposited on the optical surfaces with two different adhesion degrees have been investigated. The samples were characterized by means of the direct spectral transmittance and roughness, and compared to the initial values, before the abrasion test. Optical microscopy images have also been included in the characterization. Taking into account the spectral response of typical multijunction solar cells, the power losses due to the abrasion procedures have been calculated. [ABSTRACT FROM AUTHOR]

It is well known that CPV is sensitive to the spectrum change, and its high-performance is often discouraged by the spectrum mismatching loss by the seasonal change of the atmospheric parameters. We found multiple methods could improve the robustness to the spectrum sensitivity, including enhancing luminescence coupling and fine-tuning to the bottom-bandgap matched to local atmospheric conditions (water absorption). [ABSTRACT FROM AUTHOR]

In this work, it has been developed a method to generate non-homogeneous light patterns on multi-junction solar cells. These patterns have been generated modifying the distance between the CPV receiver and the primary optics, which is based on a Fresnel lens. In order to diminish the impact of other variables, the incident spectrum, laboratory temperature and effective concentration have been kept constant: SMRtop-mid = 1 ± 0.02, 25 ± 0.5ºC and 380 ± 3 suns, respectively. The light patterns on the top and middle subcells are measured using a CCD camera and band-pass filters. Results show that the electrical performance of the solar cells depends on the spatial and spectral profiles. The present work introduces a procedure to characterise and evaluate the impact of non-uniformities on the output of multi-junction solar cells. Nevertheless, this work is not intended to predict the actual output of the cell as a function of the light profiles, but to provide indications for possible underlying mechanisms. [ABSTRACT FROM AUTHOR]

PERC solar cell passivated on the backside with AlOx and SiNx was introduced to construct the perovskite/silicon four-terminal tandem solar cell, because of its outstanding spectral response at the long wavelength region and much lower cost than SHJ and IBC. Different from the vast majority of the related reports, which were focused on the improvement of perovskite top cell, the silicon bottom cell was optimized here to promote the tandem efficiency. The central wavelength of antireflection was adjusted to further reduce the reflectance and enhance the spectral response of PERC cell in long wavelengths, in order to make the most of long-wavelength light transmitted through the perovskite top cell. Along with the increase of central wavelength, the external quantum efficiency of PERC cell at near-infrared wavelengths increases resulting in better short circuit current density and photoelectric conversion efficiency when filtered by the perovskite cell. A tandem efficiency gain of 0.07% (abs.) has been achieved. This report provides a facile way to improve the efficiency of perovskite/silicon four-terminal tandem solar cell based on the optimization of long-wavelength spectral response. [ABSTRACT FROM AUTHOR]

In recent years, high-efficiency solar cells have a strong competitiveness in the market and the p-type PERC solar cell is the mainstream product of leading cell manufacturers. To further improve the efficiency and reduce the cost, laser doping selective emitter (LDSE) has been introduced into the mass production line as a promising technology. In this work, we fabricated high efficiency PERC solar cells by using LDSE technique. Firstly, we adjusted the diffusion process and obtained the best sheet resistance (115 ± 5 Ω/sq), which resulted in an efficiency gain of 0.11%. Subsequently, the best diffusion profile of the selective emitter was obtained through optimization. With the surface concentration of about 3.0×1020 atoms/cm³ and emitter depth of 0.32 µm, the optimum photovoltaic parameter gains have been achieved, namely 0.18% for Eff, 6.7 mV for Voc and 0.25 mA/cm² for Jsc respectively. EQE measurements show that the spectral response can be improved in the short wavelengths through introducing LDSE structure. Correscan measurements indicate that the front contact resistance of SE solar cell was slightly higher than that of reference due to the lateral transport resistance. The efficiency of LDSE solar cell can be increased further by the optimization of laser uniformity and the alignment of screen-printed finger with heavily doped region. [ABSTRACT FROM AUTHOR]

The results of measurement of the spectral sensitivity of the liquid crystal coating optical response on the skin friction shear stress and temperature are discussed. The data are given for 9 two-and multi-component compositions based on cholesteric and nematic liquid crystals with the bandwidth of the selective reflection up to 50С. Resulting compositions can be applied for the visualization and measurement of the shear stresses and/or temperature [ABSTRACT FROM AUTHOR]

Thin film solar cells were developed as an alternative to c-Si solar cells in an effort to bring down the cost. Among these the CdS/CdTe solar cell, has a high conversion efficiency as well as capability to be produced at low cost. The heterojunction CdS/CdTe solar cell shows a high spectral response in the wavelength region from 500 nm while it is much less sensitive for the region below 500 nm due to the absorption in the CdS window layer. It is suggested thatsolar spectrum can be shifted using SrB4O7:Sm2+phosphor which will absorb radiations in the wavelength region 300-500 nm and emit around 650-750 nm. This can improve the efficiency of CdS/CdTe solar cell. [ABSTRACT FROM AUTHOR]

Cadmium telluride PV is the only thin film technology with lower costs than conventional solar cells made of crystalline silicon in multi-kilowatt systems. The CdS-CdTe solar cell has a high conversion efficiency as well as capability to be produced at low cost. The heterojunction CdS-CdTe solar cell shows a high spectral response in the wavelength region from 500 nm with a sharp rise to 850 nm, while it is much less sensitive for the region below 500 nm due to the absorption in the CdS window layer. Accordingly, if sunlight in the wavelength region below 500 nm can be somehow used for the extension of the spectral response, then an increase of short-circuit current which leads to the increase of both output power and conversion efficiency will be achieved. This can be done by using downshifting phosphors which can absorb light in the region 300-500 nm and emit at longer wavelengths. Synthesis and characterization of one such phosphor viz. K2GeF6:Mn4+ is described in the present paper. [ABSTRACT FROM AUTHOR]

The effect of surface and interface states of various GaAs based structures such as n+GaAs, n-n+GaAs and p-i-n GaAs are investigated for understanding the detector performance. These structures are grown by metal organic vapor phase epitaxy (MOVPE). Surface photovoltage spectroscopy is performed in these structures to investigate the role of surface and interface states on the absorption spectra. Decrease in surface photovoltage signal with increased chopping frequency indicate the presence of slow temporal response states. These states get passivated by growing homo epitaxial layer of GaAs on n+GaAs substrate. Subsequently, for the isolation of surface and interface states on the p-i-n detector structure, n-n+GaAs and p-i-n GaAs structures are investigated separately. Further, the detectors of these structures are developed and their spectral response are recorded at room temperature. The responsivity values are evaluated by varying the incident power of 690 nm laser. Ten times increase in responsivity is observed in p-i-n GaAs photodetector compared to n-n+GaAs photodetector. A low dark current (~ 0.5 nA) is also obtained in p-i-n GaAs photodetector which qualifies its better device performance. [ABSTRACT FROM AUTHOR]

The problems of meteorological (wind) loads modeling on high-rise structures are considered. Arising oscillations lead to technical risks and uncomfortable being in residential and office rooms of these buildings. Technogenic impacts from transport and construction work can also lead to the development of negative oscillatory processes in buildings. Models describing the reactions of the structures of a building to outer impacts transmitted through geophysical media are proposed. Using spectral methods, based on decomposing of the signal into orthogonal rows for analyzing the proposed models, allows us to obtain the solution, as well as to optimize the structure of the simulation results. The use of these methods for practical tasks of non-destructive remote control is based on the considerable sensitivity of the harmonics of the spectral expansions to the values of the estimated parameters. A clamped beam model was proposed as the initial mathematical model of the considered system (building). It allows us to make simple computational schemes for analyzing of the oscillations in the structure of a building exposed to wind and technogenic loads. Many results are obtained in analytical form. The model makes it possible to investigate the resonant structure of the oscillations and correctly adjust the dampers of unwanted building dynamic reactions to external influences. The results of the analysis allow us to draw general conclusions about the danger of the excited oscillations, as well as the need to use vibration dampers. [ABSTRACT FROM AUTHOR]

Efficient NIR emission is reported for NaY(MoO4)2 activated with Nd3+ or Yb3+. Characteristic emission of rare earth ions is sensitized by MoO4-2 group. The excitation is in the near UV region of 350-400 nm. These phosphors could be useful for modifying the solar spectrum so as to match with the spectral response of c-Si solar cells. [ABSTRACT FROM AUTHOR]

We have synthesized pure and copper doped zinc oxide Zn1-xO:Cux (x = 0, 0.03) powder by wet chemical co-precipitation method followed by sintering of the co-precipitated amorphous phase powder at 450°C for 4 hours. The experiment is performed to recognize the effect of nominal doping of transition metal over the structural, morphological and optical properties. The structural parameters are observed by using Rietveld refinement of X-ray diffraction data which clearly represents that Cu ion is perfectly incorporated at the Zn site with minimal distortions within the lattice. The crystallite size is estimated by Debye-Scherrer and Hall-Williamson formulation. The particle morphology and size is determined with scanning electron microscopic (SEM) technique. The band gap and optical measurements are carried out with UV-visible absorption and photoluminescence (PL) spectroscopic technique, respectively. Enhanced PL spectral response is observed for ZnO:Cu along with non-radiative transitions from conduction band to valence band. The energy levels near the conduction band that are commonly involved in the optoelectronic transitions in the UV-region are traced by using absorption and luminescence spectral graphs. [ABSTRACT FROM AUTHOR]

Distributed Bragg Reflectors and optical microcavities are multilayer optical structures with spectral properties that are intrinsically sensitive to external perturbations. With nanometer to micrometer dimensions and near instantaneous optical response, these structures show significant potential as the basis for meso-scale time-resolved diagnostics that can be used to probe the dynamic behavior of meso-scale heterogeneous materials. In order to characterize the optical and mechanical behavior of the multilayer structures, a coupled computational-experimental approach is followed. A theoretical analysis of the spectral response of the structures to dynamic loading is shown, along with computational simulations illustrating the observable spectral effects of 1D shock compression. Results from laser driven shock loading of prototype multilayer designs demonstrate clearly observable spectral shifts closely correlated with shock pressure, indicating that the magnitude of dynamic loading can be directly inferred from the altered spectral response of the multilayer structure. [ABSTRACT FROM AUTHOR]

Bao'An Stadium is a unique structure that utilises 54m span cantilevers with tensioned members to support the roof. This report involves a simplified finite element model of Bao'An stadium using Strand7 to analyse the effects of deflections, buckling and earthquake loading. Modelling the cantilevers of the original structure with a double curvature was problematic due to unrealistic deflections and no total mass participation using the Spectral Response Solver. To rectify this, a simplified symmetrical stadium was created and the cable free length attribute was used to induce tension in the inner ring and bottom chord members to create upwards deflection. Further, in place of the Spectral Response Solver, the Transient Linear Dynamic Solver was inputted with an El-Centro earthquake. The stadium's response to a 0.20g earthquake and self-weight indicated the deflections satisfied AS1170.0, the loading in the columns was below the critical buckling load, and all structural members satisfied AS4100. [ABSTRACT FROM AUTHOR]

In general, Fiber Bragg Grating (FBG) sensor works based on observation of spectral response characteristic to detect the desired parameter. In this research, we studied intensity response characteristic of FBG to detect the dynamic strain. Experiment result show that the reflected intensity had linier relationships with dynamic strain. Based on these characteristics, we developed the FBG sensor to detect low frequency vibration. This sensor is designed by attaching the FBG on the bronze cantilever with dimensions of 85x3x0.5 mm. Measurement results showed that the sensor was able to detect vibrations in the frequency range of 7-10 Hz at temperature range of 25-45 °C. The measured frequency range is still within the frequency range of digging activity, therefore this vibration sensor can be applied for oil pipelines vandalisation detection system. [ABSTRACT FROM AUTHOR]

The aim of this work is design and thermal management of energy effective LED module for poultry lighting. The spectral sensitivity of fowls differs significantly from that of humans and primary objective of this work is to match as close as possible the spectral power distribution of artificial light source to the spectral characteristics of the poultry vision. In different stages of growth of poultry adequate illumination of premises varies very widely. Therefore essential requirement to luminaires for such purposes is the possibility of their luminous flux to be dimming over a wide range while retaining its spectral distribution. These tasks have been successfully resolved in the designed module by selecting the appropriate LEDs and management regimes. Proper thermal management ensures safety regimes of operation of the LED module even at heaviest ambient conditions (temperatures up to 45°C). [ABSTRACT FROM AUTHOR]

The direct normal spectral responsivity of the Ll-COR photodiode pyranometer is examined, using DN1 spectral data from a PMOD Spectroradiometer and the generic spectral response of a LI-COR pyranometer. The spectral responsivity is found to vary over the day as more blue light is scattered as the air mass increases. The SMARTS2 model is used to examine the effect on the full spectral response range of the photodiode based pyranometer and to refine the estimated response changes. The use of this information is discussed relative to improving corrections to Rotating Shadowband Irradiometers. Similar methodology can be used to estimate the spectral effect on the performance of solar modules. [ABSTRACT FROM AUTHOR]

This work presents attenuation and sensitivity measurements of radiographic imaging plates (IPs) with quasimonoenergetic X-rays in the 8-60 kiloelectronvolt range. The measurements are used to validate theoretical predictions. A short overview of the theoretical model is given. The model can be used to describe the sensitivity of different detector types to a wide range of X-ray energies. [ABSTRACT FROM AUTHOR]

Near infrared imaging is a powerful technique for the analysis of ancient paintings, allowing the nondestructive examination of features underneath the pictorial surface. Beyond the unique nature of the artwork (materials and layer stratigraphy), the effectiveness of the technique in detecting any painting features is determined by the device performance (spectral sensitivity, acquisition band narrowness, spatial resolution) as well as by the irradiation setup. We performed multi-modal infrared imaging on a XVI century masterpiece by Titian using an InGaAs camera and different measurement setup. Acquisition was carried out in conventional reflection geometry and in trans-irradiation mode, as well as in wideband and multispectral modes. Preliminary results are presented and the potentialities of such infrared analysis discussed. [ABSTRACT FROM AUTHOR]

A Yankee Environmental Systems (YES) UVB-1 ultraviolet pyranometer, designed to measure erythemally weighted total solar irradiance, was calibrated by the Measurement Standards Laboratory (MSL) in Lower Hutt, New Zealand during August 2010. The calibration was then repeated during July and August 2011 by the Physikalisch-Meteorologisches Obervatorium Davos, World Radiation Center (PMOD/WRC) located in Davos, Switzerland. Calibration results show that measurements of the relative spectral and angular response functions at the two institutes are in excellent agreement, thus providing a good degree of confidence in these measurement facilities. However, measurements to convert the relative spectral response into an absolute calibration disagree significantly depending on whether an FEL lamp or solar spectra are used to perform this scaling. This is the first serious comparison of these scaling methods to formally explore the potential systematic errors which could explain the discrepancy. [ABSTRACT FROM AUTHOR]

In this work we present and discuss the effects of different scintillation models on the Normalize Differential Spectral Attenuation (NDSA) measurements in a counter-rotating Low Earth Orbiting (LEO) set event at 17, 19, 21, 32, 179 and 182 GHz. Some parameters of the scintillation models used here are computed at global scale using an European Centre for Medium-Range Weather Forecasts (ECMWF) global dataset. The scintillation effects on the NDSA measurements are analyzed in terms of relative error of the their estimation. [ABSTRACT FROM PUBLISHER]

PV based large scale energy generation has spread significantly. In spite of similar technical parameters the amount of yearly produced energy may differ by notable percents. It results from the operation of solar trackers and also from the different spectral behavior of the different PV panel types. In this paper we introduce a novel on site spectral sensitivity measurement method. The spectral characteristic is recalculated from separate power maximum measurements, where the measurements are made by spectrally different natural irradiation (sunrise, noon, foggy, cloudy, etc.). [ABSTRACT FROM PUBLISHER]

In this paper the main objectives of the ESA-ANISAP study are summarized and the first results are presented. The existing end-to-end software simulation tool developed for a couple of counter-rotating Low Earth Orbiting (LEO) satellites has been upgraded and utilized for this work. The Integrated Water Vapor (IWV) - Spectral Sensitivity (SS) and the Integrated Liquid Water (ILW) - SS relationships are shown assuming the acquisition of IWV and ILW at 3,6, and 9 km tangent altitude jointly with that of SS at 17, 19, 21 and 32 GHz. Such relationships are obtained for a global set of atmospheric vertical profiles, in order to compute the regression coefficients of the IWV-SS and ILW-SS relationships based on a linear least squares fit. [ABSTRACT FROM PUBLISHER]

Image processing modifies images to improve them (enhancement, restoration), extract information (analysis, recognition), and change their structure (composition, image editing). Image Enhancement is simple and most appealing area among all the digital image processing techniques. The main purpose of image enhancement is to bring out detail that is hidden in an image or to increase contrast in a low contrast image [1]. The color restoration functions of some real color image enhancement algorithms are greatly at random and not proved , and the real color images enhanced which are based on illumination-reflectance model have the loss of details and the 'halos', we proposed a new algorithm to overcome these disadvantages. Firstly, we transform the real color image from RGB space to HSI space which is approximately orthonormal system. Secondly, the illumination and the reflectance of value are separated by homomorphic filtering based on illumination-reflectance model. We have discovered that the high dynamic range of image including high bright lights is mainly caused by the reflectance. Thirdly, the details of reflectance are preserved by wavelet transform. Fourthly, the dynamic range of reflectance is compressed by Butterworth filtering. Lastly, the energy of the saturation of real color image in HSI space is attenuated according to the spectral sensitivity of most human vision. [ABSTRACT FROM AUTHOR]

Different from crystalline silicon solar cells, CPV using III-V multi-junction cells does not receive great influences from temperature, rather receives from solar spectrum. Some rating values related to spectrum sensitivity are needed both for the label of modules and the energy rating. Generally, an accurate model needs measurement of many parameters, which is not always accurate and requires complicated calculations. First, input parameter should be common and easy to measure. This simplicity is important for repeatability among manufactures and testing labs. Second, input parameter is not vector but scalar value. In this regards, data set from direct solar spectrum is not appropriate. Third, output parameter that describes spectrum sensitivity is a single value. The method proposed by this paper is energy or capacity factor is expressed by quadric function of DNI. [ABSTRACT FROM AUTHOR]

A theoretical analysis on the spectral sensitivity of the bandgap design of four practical III-V triple-junction solar cell structures is presented. The underlying solar cell model uses the detailed balance method. Six locations on Earth are investigated for which the monthly average of the measured aerosol optical depth and the precipitable water are used to calculate direct solar spectra with a discretisation of one spectrum per hour. The model is used to analyze the solar cell designs for the highest yearly energy production. Furthermore, the ideal bandgap combination for a maximal energy harvest is calculated for each location. It is shown that the metamorphic solar cell structure of Ga0.35In0.65P/Ga0.83In0.17As/Ge with transparencies optimized for the standard AM1.5d reference spectrum leads to the highest energy harvesting efficiencies and shows the lowest spectral sensitivity. The standard lattice-matched structure of Ga0.50In0.50P/Ga0.99In0.01As/Ge shows the highest spectral sensitivity with up to 10.8%rel difference in the yearly energy harvesting. [ABSTRACT FROM AUTHOR]