In the presented paper the structural changes in thin olive oil layers taking place as a result of interaction with water using a photoacoustic technique were studied. The oil layers were spread from a solution in a volatile solvent (ethyl ether) on the water and copper surface. These studies are a natural continuation of the previous work on a layered system performed within the light range (680 nm), which pointed to the irregularities of oil layers related to their thickness is now expanded to the infrared band. A structural irregularity was observed for a layer thickness of 100 μm, but it did not appear for the one of pure bulk oil. Signatures of irregularity were clearly observed in the phase plots whereas the amplitude dependences were not sensitive to them. The performed studies allowed one to relate the diversity of thermal parameters in the samples with structural changes found in oil layers originated from oil-water interactions.
The accurate detection of product defects in the assembly line is crucial to any industry. To achieve accurate detection, extensive studies have been conducted, in particular, on the nondestructive inspection technique. Shoe manufacturers, however, have yet to adopt a reliable defect-detection technique for their total inspection system. The deterioration of strength, one of the most common defects found in the shoe manufacturing process, is caused by the delamination in the bonding stage. Inadequate bonding between midsole and insole, the most serious of identified defects, has so far been detected only by cutting a sample shoe and examining it for its strength. For this study, the researcher tested the validity of some nondestructive techniques employed in inspecting shoes, particularly the infrared thermography technique and non contact air coupled ultrasonic testing, which are used to examine the bonded part of shoes made from ethylene vinyl acetate (EVA), the most common material used in manufacturing shoes. The study has thus confirmed the feasibility of applying a total inspection and nondestructive inspection technique to shoe inspection.
The scope of this study was the removal of heavy metal ions, ammonium and organic substances by ion exchange from municipal wastewaters. Clinoptilolite, bentonite, and palygorskite are especially interesting in the group of inorganic sorbents because of their specific physico-chemical properties. Specific surface areas and pore distributions were determined for the above sorbents. Sorption kinetics of Zn(II), Cu(II), Ni(II), Pb(II) and ammonium ions in synthetic solutions and wastewaters were investigated on the above sorbents. Ion sorption process was carried out with a static method at various phase contact times. The atomic adsorption spectroscopy method was used for measurements of heavy metal contents. The adsorption process was found to be pH and concentration dependent. The removal mechanism of metal ions was by adsorption and ion exchange processes. The FT-IR photoacoustic spectroscopy method was used to study mechanism of Zn(II), Cu(II), Ni(II), Pb(II) and ammonium ions sorption on the clinoptilolite, bentonite and palygorskite. The spectra of FT-IR/PAS before and after sorption of Zn(II), Cu(II), Ni(II), Pb(II) and ammonium ions were investigated.
Clays and zeolites are some of the most important industrial minerals. They have practical applications in geology, agriculture, construction, engineering, process industries, and environment. This article is about one of them: radioactive waste disposal. We are investigating characteristics of bentonite clay and clinoptilolite in case of Cs(I), Th(IV), U(VI) sorption.
The possibility of removal of copper(II) complexes with ethylenediaminetetraacetic acid (EDTA) from waters and wastewaters by the chelating ion exchangers Lewatit TP 214, Lewatit TP 260 and Diaion CR-20 as well as the mechanism of their sorption onto them were investigated. In order to describe the sorption process of Cu(II) ions in the presence of EDTA, the FT-IR/PA spectra of the abovementioned chelating ion exchangers were recorded.
Chromium is a major pollutant for the environment, usually as a result of some industrial pollution. Chromium is used in various industries such as metallurgical (steel, ferrous and nonferrous alloys), refractories (chrome and chrome-magnesite), and chemical (pigments, electroplating, tanning). For this reason, significant amounts of chromium pass into the environment and cause adverse ecological effects. In the present paper the investigations of solvent impregnated resin preparation was conducted. Photoacoustic and diffuse reflectance spectra were recorded for the prepared solvent impregnated resin. Photoacoustic spectra in the infrared area allow distinguishing the differences between the sorbent applied before and after the impregnation process. Impregnation of resin is a result of physical sorption of Aliquat 336 on macroporous Amberlite XAD 16.
The paper makes an attempt to create a polymer sorbent competitive for the commercial Lewatit OC-1026. Therefore the commercial Amberlite XAD-7 was impregnated with the D2EHPA acid. After preparation of both exchangers, their sorption properties towards In(III) and Ga(III) ions were studied [1]. It proved that for pH = 2.17 Amberlite XAD-7 impregnated with D2EHPA acid is characterized by larger sorption capacities than those of commercial Lewatit OC-1026 towards both Ga(III) and In(III) ions. Lewatit OC-1026 as well as the prepared impregnant (XAD-7 + D2EHPA) were examined by means of Raman spectroscopic, FT-IR photoacoustic spectroscopy and FT-IR methods.
The annealed low alloy 4140 steel samples have been nitrided for different treatment periods (1-6 h) in an RF inductive plasma discharge with very low bias voltage ( ≈ 400 V). The resulting nitrided layer has been observed by means of an optical microscope whereas the nitride phases have been characterised by X-ray analysis. The corrosion response, assessed by the potentiodynamic tests in the 3.5% NaCl solution, presents both higher noble potential values and lower corrosion rates when compared with the untreated sample. The Vickers microhardness tests values show an appreciable increment compared to that of the untreated sample. The process is characterized by a high overall efficiency because similar average Vickers tests values were obtained, no matter for how long the treatment was extended. Likewise, the scanning electron micrographs confirmed no appreciable size evolution of the compound layer microstructure at different times of treatment.
In this paper, we report a study on the optical properties of xenon ion implanted CuInSe_2 single crystals using a high resolution near-infrared photoacoustic spectrometer of the gas-microphone type. Samples of high quality of CuInSe_2, p-type conducting, have been implanted with Xe^{+} at 40 keV with doses of 5 × 10^{15}, 10^{16} and 5 × 10^{16} ions/cm^2. Photoacoustic spectra have been measured before and after implantation. A newly developed theoretical model based on a two-layer sample configuration has been used to single out the spectral dependence of the absorption coefficient of the implanted layer from that of the substrate. The absorption spectra were used to evaluate the gap energy and to establish ionization energies for several shallow and deep defect states. The resulting effects following the introduction of xenon into CuInSe_2 at different doses are discussed in the light of published literature.
This work presents the modern approach to the detection of various types of defects in composite structures used in aerospace. In such structures, including glass reinforced plastics and carbon reinforced plastics, different failure modes could occur at a manufacturing stage and during service life. Defects are connected with inadequate technology, poor workmanship, cycling fatigue loads, impact damage and environmental conditions. The main types of defects are delaminations, disbonds, foreign object inclusions and porosity. To detect such defects, several non destructive evaluation techniques can be applied, merely to mention ultrasonic, low frequency acoustics, infrared thermography and shearography. The use of multimode non destructive evaluation techniques enables characterization of defects which cannot be detected by using single non destructive evaluation methods. This paper demonstrates the necessity of using non destructive evaluation methods for the implementation of quality control and maintenance procedures while servicing aerospace composite elements.
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