Papers by Keyword: IR

Abstract: In this article, a picosecond laser source was employed to irradiate the nanostructured ZnO thin film prepared by the sol-gel method. The impact of laser irradiation on the characteristics of a nanostructured ZnO thin film was investigated. Analysis using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy confirmed a significant influence on the structure of the ZnO thin film. As the duration of laser irradiation (the number of laser pulses) increased, there was a remarkable decrease in both the electronic and photoluminescence intensities of the nanostructured film. Tauc's plot indicates a noticeable change in the optical band gaps of the thin film with the increase in irradiation time. The morphological image suggests that the laser irradiation energy induces both degradation and modification of the film surface, consequently causing changes in the structural, absorption, and photoluminescence properties of nanostructured ZnO. The observed effects are attributed to alterations in the crystal structure and size of the nanostructured ZnO film, as confirmed by XRD. The reduction in photoluminescence intensity observed over the laser irradiation times may be a result of potential degradation in the crystalline structure of the nanostructured ZnO film.

Abstract: L'objectif de ce travail est la caractérisation morphologique et physico-chimique d'échantillons de sols issus d'activités d'orpaillage dans la région de Komabangou (Niger). Les analyses ont été réalisées à l'aide d'un microscope électronique à balayage couplé à la spectroscopie dispersive en énergie (SEM-EDS), d'un pH-mètre, d'un COT-mètre et par infrarouge. Les résultats obtenus ont montré que les sols des sites étudiés sont généralement acides. En effet, l'analyse infrarouge donne les constituants majoritaires : silice, calcite, aluminium, fer et magnésium. L'analyse MEB a montré la présence de feuilles d'argile dispersées sous forme de filaments ou d'amas d'agrégats qui peuvent être dus à la présence de carbonates ainsi qu'à la présence d'éléments traces métalliques. L'analyse par spectroscopie d'énergie dispersive (DES) du sol pollué du site (S1) a révélé la présence de 60,25 % d'oxygène (O) ; 18,70 % de carbone (C); 8,34 % de silice (SiO₂ ); 4,72 % d'aluminium (Al); 0,86 % de fer (Fe); 0,79 % magnésium (Mg); 0,12 % de titane (Ti); 0,11 % de zinc (Zn); 0,06 % de cadmium (Cd) et 0,0 % de plomb (Pb). En revanche, pour le site périphérique (S3), on note 77,09 % d'oxygène (O) ; 14,49 % de silice (SiO ₂ ); 8,89 % d'aluminium (Al); 1,11 % de fer (Fe); 0,34 % de potassium (K) et quelques traces de manganèse (0,03 %) ; cobalt (0,01 %) ; cuivre (0,01 %) ; nickel (0,01 %) ; chrome; cadmium; mener. Enfin, le site témoin (ET), qui est vierge, contient 67,56 % d'oxygène ; 17,86 % carbone; 9,18 % silice; 4,28 % aluminium ; 0,91 % de fer et 0,13 % de potassium.

Abstract: The combination of carbon nanotubes (CNT) and conducting polymers offers an attractive route for the production of novel compounds that can be used in a variety of applications such as sensors, actuators, and molecular scale electronic devices. In this work, functionalized multiwall carbon nanotubes (f-MWCNTs) were added in different load ratios (3 wt%, 5 wt% and 10 wt%) to thiophen (PTh) polymer to procedure PTh/CNTs nanocomposite and deposited on porous silicon substrate by electropolarization. Photoconductive detectors were fabricated using PTh/f-MWCNTs matrix to work in the near region and middle IR regions. These detectors were illuminated by semiconductor laser diode wavelength of 808(nm) and Nd-YAG laser of wavelength 1064 (nm) to study the I-V characteristics and figures of merit. FTIR spectra assignments verify that the thiophene groups were successfully introduced into the carbon nanotubes. SEM images reflect that the electro polymerization process gives well coating for the CNTs by PTh. The conductivity of PTh as a function of temperature increased about 30 times due to addition of f-MWCNTs. Figures of merit reflect a good IR radiation sensitivity and photo response. The specific detectivity was in order of 10⁸ (cm.Hz^1/2/W) for both IR regions. The rise and fall times of the output signal are about of 192 (μs) and 121 (μs) respectively for load ratio 5wt% of CNT, which consider good values for these types of detectors.

Abstract: This paper explains and demonstrates the aging performance and structure of bio-asphalt with analytical results from hot stage microscopy, infrared spectroscopic and nuclear magnetic resonance spectra. The experimental results showed that the aging of bio-asphalt is mainly caused by a large amount of coke substance generated during the process, and the addition of BHT can improve the aging resistance of bio-asphalt to some extent. Catalytic hydrogenation facilitate the removal of aldehyde, ketone and carbon-carbon double bond so as to strengthen the aging resistance of bio-asphalt, nuclear magnetic analysis further confirms the results from IR .

Abstract: The P-type transparent conductive oxide CuAlO₂ was prepared by solid state reaction in this paper. The chemical state, phase structure, microstructure and optical properties were characterized by Differential Thermal Analysis ( DTA),X-ray diffraction ( XRD),Scanning Electron Microscope ( SEM) and Infrared Spectroscopy ( IR) respectively. Testing results show that the product is really p-type transparent conductive oxide CuAlO₂. CuAlO₂ phase began to form at about 1047.7 °C.It can be formed with high density and a high infrared light transmittance of the conductive oxide at 1150 °C.

Abstract: In this paper, the relative change rates of content of conjugated fatty acid glycerides, content of tans-fatty acid glycerides, unsaturation and linear long-chain fatty acid glycerides were explored after being at high temperature for several hours by using FTIR-ATR. The results hints:1.Starting from 160°C, the contents of conjugated fatty acids glycerides and trans-fatty acid glycerids in the vegetable oils increase but unsaturation and content of linear long-chain fatty acid glycerides decreases with heating temperature and heating time increasing; 2. When heating temperature reaches 200°C or more, the heating time up to four hours or longer, the four indicators (conjugated fatty glycerids, trans-fatty acid glycerids, unsaturation and linear long-chain fatty acid glycerides) of five kinds of vegetable oils have substantial changes; 3. The content of linoleic acid in the vegetable oil has some contributions to the change amplitude of contents of conjugated fatty acid glycerides, and the content of oleic acid in the vegetable oil has some contributions to the change amplitude of content of trans-fatty acid glycerides. Because refined “waste oil” experiences a longer history at temperature higher than 200 °C compared to the vegetable oil, four index value and its variation can be used as specific indicators for it.

Abstract: In this work, the dissolution of iridium was studied through a thermodynamic theoretic study with different concentrations of hydrochloric acid (HCl) and Iridium (Ir). Three different acid conditions and three different concentrations of iridium were analyzed: 1, 0.1 and 0.01 M HCl and 0.86, 0.021 and 0.002 M of iridium. The system 1 M HCl was the only one that presented soluble species of Ir. Results showed that as the Ir concentration diminished from 0.86 to 0.002 M, the pH range where it is possible to obtain Ir soluble species, increased (from 0-1.2 to 0-2). The presence of two Ir species (valences III and IV) for 0.021M and 0.002 M Ir concentrations was determined from the Pourbaix diagrams; while for the 0.086 M concentration, only the Ir (IV) species was observed. The Pourbaix diagrams showed that it is possible to obtain the species iridium (IV) from a potential range of 0.823 V vs SHE to 1.422 V vs SHE and at a pH between 0 and 1.2 in the 1 M HC1 solution.

Abstract: Sika deer antler velvet layer is a kind of precious traditional Chinese medicine, which has been widely used for treatment of some diseases. In this study the extraction of ganglioside from the lipid soluble fraction of sika deer antler velvet layer was investigated. The quantitative effects of ratio of liquid to raw material, temperature, time were investigated for extraction of ganglioside. The optimal ganglioside extraction conditions were determined: ratio of liquid to raw material 11, temperature 40°C and time 7min. Residue which was separated from the lipid soluble fraction of sika deer antler velvet layer was proved to be ganglioside by IR.

Abstract: The adsorption of propylene oxide (PO) onto MgO, ZnO and Al₂O₃ was investigated by using in situ-IR measurements. Detailed mechanisms for PO adsorption onto these metal oxides are proposed. It was found that the PO epoxide ring exhibits two opening tendencies, depending on the acid-base properties of the metal oxide. PO adsorbed onto MgO is preferentially opened at the O-C (1) bond. The epoxide ring provides two ways to open, at the O-C (1) or the O-C(2) bond on Al₂O₃. PO adsorbed onto ZnO showed no chemical adsorption on its surface.

Abstract: Zein was added into wheat gluten (WG) to prepare zein composite films (ZCF) in order to improve the properties of films. The film-forming ability, properties, surface microstructure and infrared spectrum of WG films and ZCF were investigated. The results show that the viscosity of film-forming solutions decrease, and uniformity become worse slightly, after zein added. ZCF are yellow, with metal luster, whose toughness and water retention increase. Compared to the control, the ZCF tensile strength (TS), elongation at break (EB) and resistance of oxygen are increased by 33.2%, 17.2% and 11.25%, and water vapor permeability (WVP) and transparency are decreased by 26.0% and 75.4% respectively. ZCF have better antibacterial properties than WG films. The inhibition effect on escherichia coli and staphylococcus aureus are increased by 36.36% and 32.89% respectively. Hydrogen bond interaction of ZCF become weak, and the surface of ZCF become smooth and evenly.