Sharif Digital Repository

Over the last two decades there have been numerous reports from different seismically active regions of the world that thermal infrared (TIR) anomalies can be identified around the epicentral areas before major earthquakes [e.g. (Tronin et al., 2002)]. The TIR anomalies reportedly appear as early as 14 to 7 days before the seismic events and affect areas as large as 1000s to 100,000s km2 in size. Our case study for detection of TIRs using NOAA-AVHRR data(Band 4) is an Ms = 5.1 earthquake that occurred on 14th October 2004 near Ravar in Kerman province located in Loot and Tabas deserts, southeast-central Iran. The area is part of the Golbaf-Sirj seismogenic zone. It includes major faults... 

This paper proposes a novel fusion method for visible and infrared images. The infrared and visible samples are obtained by a sampling pattern such as star and spiral. Then, the samples are fused according to fusion rules. Finally, the proposed method is applied to fuse the infrared and visible samples. The proposed method is iterative and a significant advantage of it, besides its superior performance, is that it is faster than the previous compressive sensing based fusion methods. The simulation results confirm the success of the proposed method for fusion of infrared and visible images. © 2018 IEEE  

Chemical fertilizers are widely applied in agriculture to achieve high yield, enhance produce quality and build resistance to diseases; in our case the plant being tomato (Solanum lycopersicum L. var. Royal). However, the acidity, size and taste of tomato fruits could change with excess nitrogen (N) application. The present study aims at the early detection of nitrogen-rich tomato leaves using hyperspectral imaging techniques in the visible and near infrared (Vis-NIR) spectrum, in order to improve plant nutrition composition at an early growth stage. A 30% over-dose of nitrogen was applied to half of the tomato pots. Five leaves were randomly collected from each pot for 3 days (classes D0,... 

Diffused infrared transmission is one of thepreferred techniques used in indoor wirelesscommunications. Tolerance to shadowing and a lack ofalignment requirements are among the many advantagesoffered by this technique compared to the line-of-sighttechniques. However, it has its disadvantages, namelyhigh path loss and multipath dispersion. The limitationimposed by eye-safety requirements restricts the transmitted power. Therefore, efficient useof transmitted optical power is the key for practicalbroadband infrared systems. In this paper, we report onusing a holographic diffuser for shaping of infrared radiation pattern in an indoorinfrared transmission system. The holographic diffusershave... 

The specific adsorption of citrate from perchloric acid electrolytes, has been investigated using in-situ FTIR spectroscopy at Au(1 1 1) electrodes. For comparison IR spectra for formate adsorption are also presented. Clear voltammetric peaks have been observed positive of the pzc and these are shown by FTIR spectroscopy to be associated with the adsorption of citrate. Models for the surface co-ordination of the citrate anion are discussed. © 2002 Elsevier Science B.V. All rights reserved  

In this paper we propose the use of pulse shaping for mitigating the effect of channel distortion on the performance of indoor wireless infrared (IR) CDMA systems. The bit error rate (BER) performance of an on-off keying (OOK)-CDMA system as a function of the average transmitted power is investigate& To this end, photon-counting model is utilized and major noises such as shot noise, ambient light, dark current, and receiver thermal noise are taken into consideration. It is shown that using appropriate pulse shapes, the system performance will be improved and the required transmitter power will be reduced. ©2002 IEEE  

This study focuses on the spectrochemical estimation of pH and titratable acidity (TA) of apples of Fuji variety at different stages of ripening. A novel approach is proposed for near-infrared (NIR) spectral analysis using hybrid machine learning methods that combine artificial neural networks (ANN) and metaheuristic algorithms. One hundred twenty samples were collected at three ripening stages and spectral data within two bands of NIR were extracted from each sample to predict the acidity properties. Alternatively, the 4 most effective wavelengths were also selected using a hybrid of ANN and the cultural algorithm. The experimental results prove that the models using spectral bands and the... 

A novel superabsorbent composite system based on carboxymethyl cellulose (CMC) was prepared by graft copolymerization of acrylic acid (AA) in the presence of kaolin powder using methylenebisacrylamide (MBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator. The effect of reaction variables, such as MBA, AA, and APS concentration and CMC/kaolin ratio on the water absorbency of the composite were studied. Evidence of grafting and kaolin interaction was obtained by comparing the FT-IR spectra of the initial substrates with that of the superabsorbent composite. The results indicated that with increasing amount of kaolin, the swelling capacity was increased and then... 

The effects of the most important parameters of hot pressing, including temperature, time and pressure on densification, microstructure and infrared transparency of MgF2 ceramics are discussed. The results show that the absorption or scattering of incident radiation is strongly dependent on the amount of porosity. By increasing the temperature or the pressure, transparency at infrared wavelengths has been increased due to the rise in density. For the longer hot pressing times, a continuous increase in density and infrared transparency has been seen as well. Cold pressing before hot press has minor effects on the density and infrared transparency of MgF2. © 2008 Elsevier B.V. All rights... 

A new and simple receiver structure for reducing the multipath inter-symbole interference (ISI) effect is proposed for infrared diffuse links. In this new method, bit-error rate (BER) performance of the system will be improved significantly without any essential change in the receiver structure. In our analysis, all major noise sources such as ambient light, signal shotnoise, dark current and thermal noise of the receiver are considered. © 2009 IEEE  

This paper presents a novel approach for designing dual-band absorbers based on graphene and metallic metasurfaces for terahertz and mid-infrared regimes, respectively. The absorbers are composed of a 2D array of square patches deposited on a dielectric film terminated by a metal plate. Using an analytical circuit model, we obtain closed-form relations for different parameters of the structure to achieve the dual-band absorber. Two absorption bands with an obtained absorptivity of 98% at 0.53 and 1.53 THz for the graphene-based structure and 7 and 25 THz for the metallic-based case are achieved. We demonstrate that the graphene-based absorber remains as the dual band for a wide range of the... 

In this research, the effect of Fe2O3 content on the electrochromic properties of WO3 in thermally evaporated (WO3)1-x-(Fe2O3)x thin films (0 ≤ x ≤ 0.4) has been studied. The atomic composition of the deposited metal oxides was determined by X-ray photoelectron spectroscopy analysis. The surface morphology of the thin films has been examined by atomic force microscopy. The surface roughness of all the films was measured about 1.3 nm with an average lateral grain size of 30 nm showing a smooth and nanostructured surface. The electrochromic properties of (WO3)1-x-(Fe2O3)x thin films deposited on ITO/glass substrate were studied in a LiClO4 + PC electrolyte by using ultraviolet-visible... 

Drying of green peas in a Fluidized Bed Dryer (FBD) with inert particle, heated by combined sources of hot air and InfraRed (IR) radiation, has been experimentally and theoretically studied. For this purpose, an experimental set up was constructed. This setup was composed of a cylindrical bed dryer containing some inert particles which are fluidized by hot air. Some infrared lamps were also placed around the bed for heating assistance. A sample of green pea was hung in the fluidized bed and its moisture content, surface and central temperature were measured with time. A mathematical model, based on the two layers concept of penetration and conduction was also proposed for this process. The... 

The current study presents an application of near infrared spectroscopy for identification and quantification of the fraudulent addition of barley in roasted and ground coffee samples. Nine different types of coffee including pure Arabica, Robusta and mixtures of them at different roasting degrees were blended with four types of barley. The blending degrees were between 2 and 20 wt% of barley. D-optimal design was applied to select 100 and 30 experiments to be used as calibration and test set, respectively. Partial least squares regression (PLS) was employed to build the models aimed at predicting the amounts of barley in coffee samples. In order to obtain simplified models, taking into... 

Diffuse reflectance near-infrared (NIR) data (908–1676 nm) of chicken breast fillets was recorded in a non-destructive way using a portable miniaturised NIR spectrometer. The NIR data was used to discriminate between fresh and thawed breast fillets and to determine the birds’ growth conditions. NIR data was recorded of 153 commercial supermarket chicken fillet samples by applying the NIR device equipped with the standard issue collar on the samples in three different ways: (i) directly on the meat (ii) through the top foil of the package (i.e. with an air pocket between the foil and the breast fillet), and (iii) through the top foil with the packaging turned bottom up (i.e. no air pocket... 

The effect of the superconductivity transition on the thermal crosstalk in YBa 2Cu 3O 7-x, edge-transition bolometer arrays is investigated for DC to midrange modulation frequency infrared radiation. The bolometers in the arrays were designed with various distances on SrTiO 3 (100) substrates. We have observed a change in the thermal crosstalk between neighbor devices through the superconductivity transition temperature range. Superconductivity transition dependence of the thermal coupling between the devices was measured by utilizing the thermal conductance measurement methods developed for the bulk material. The knee points in the magnitude of the response versus modulation frequency... 

In the present work, a new approach based on external parameter orthogonalization combined with support vector machine (EPO-SVM) is proposed for processing of attenuated total reflectance-Fourier transform mid-infrared (ATR-FT-MIR) spectra with the goal of solving authentication problem in saffron, the most expensive spice in the world. First, one-hundred authentic saffron samples are clustered by principal component analysis (PCA) with EPO as the best preprocessing strategy. Then, EPO-SVM is used for the detection of four commonly used plant-derived adulterants (i.e. safflower, calendula, rubia, and style) in binary mixtures (saffron and each of plant adulterants) and its performance is... 

Background: The seminal plasma is an excellent source for noninvasive detection of spermatogenesis. The seminal plasma of normospermic and azoospermic men has been analyzed for detection of spermatogenesis. Methods: Optical spectroscopy (Attenuated Total Reflectance-Infrared spectroscopy (ATR-IR) and Fourier Transform infrared spectroscopy (FT-IR) has been used to analyze the seminal plasma and the metabolome of seminal plasma for detection of spermatogenesis. Results The seminal plasma of normospermic and azoospermic men has been analyzed by ATR-IR. The results show that there is a pattern variation in the azoospermic men compared to normospermic men. However, the seminal plasma is too...