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1
Content available remote Near infrared imaging of micro-structured polymer-metal surface pattern
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Two-dimensional infrared scanning microscopy images of micro-structured surface patterns in an organic transistor device with metal electrode stripes on a polymer channel layer have been demonstrated. A compact single mode optical fiber scanning probe which has a micro dome-shape lens at the tip end was used for the scanning in which reflected beam intensities are coupled back to the optical fiber transceiver depending on the returned power of the sample material. Based on the experiment, the obtained structural dimensions of the micro structure specimen were well matched to the designed ones. These images were compared to the digital microscopy photos for a potential usage to conduct not only the in situ microscopic electrode pattern monitoring of the device but also to non-destructively investigate any surface reflecting material in micrometer scales.
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Assuming that a maldistribution of media flow may have significant meaning for a cross-flow heat exchanger performance it is important to determine the form and scope of this non-uniformity. Experimental investigations of this problem are conducted for over ten years at the Institute of Thermal Technology of the Silesian University of Technology by using a computer controlled thermoanemometric probe. This is a very invasive technique that applies properly only in laboratory conditions. As the infra-red thermography was applied at some stage of realized studies, the authors assume a possibility of applying this technique for evaluation of media flow maldistribution, qualitative assessment at least. The experiments performed for the case of a typical fin and tube water cooler have been described in this paper, as well as the most important conclusions.
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Content available remote Configuration of systems for testing thermal imagers
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Systems for testing thermal imagers offered commercially are built from the same modules: an off-axis reflective collimator, a motorized rotary wheel, a set of IR targets, a black body, a black body/wheel controller, a PC and some software. The classical solution is that all these components are located horizontally on an optical table. However, it is also possible to use a vertical configuration of the test system when the rotary wheel is put on the collimator and the black body is put on the rotary wheel. It was shown in this paper that when the vertical configuration is used, then better temporal stability and spatial uniformity of the thermal images projected by the test system can be achieved.
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Content available remote Mid-wave infrared liquid crystal shutter for breathalyzer applications
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There exists a problem with an in situ diagnostics of contamination of ethyl alcohol in a human being exhaled air. When ethyl alcohol in a mouth blowing (in a gaseous state) exists, the characteristic C-H stretch absorption bands in CH3 and CH2 functional groups in ethanol (CH3CH2OH) appear at a wave length of λ = 3.42 µm. To investigate the presence of ethyl alcohol in exhaled human air, the light beam of λ = 3.42 µm is passing through an air sample. If one alternately measures the intensity of the investigated beam and the reference, a percentage of ethanol in the air sample can be estimated using a sensitive nondispersive infrared (NDIR) system with a stable operating flow mass detector. To eliminate a mechanical chopper and noise generating stepper motors, a photonic chopper as a liquid crystal shutter for λ = 3.42 µm has been designed. For this purpose, an innovative infrared nematic liquid crystal mixture was intentionally prepared. The working mixture was obtained by a selective removal of C-H bonds and its exchange by heavier polar substituents, what ensures a lack of absorption band of C-H bonds. The paper presents theory, concept and final experimental results of the infrared nematic liquid crystals mixture and the liquid crystal shutter for breathalyzer applications.
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The paper presents the principle of operation of a new night-shooting target. Because this target requires a covering that reflects the infrared radiation flux generated by the reflector from its surface, testing of different variants of the cover and the shape of the target surface has been carried out. Emissivity is a physical parameter characterizing the radiant properties of real bodies. The emissivity coefficient of extruded aluminum sheet samples covered with a layer of green colored aluminum oxide was determined. The aluminum oxide layer was applied using two different technologies being galvanic and anodizing.
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Content available remote Compact dual-band FTIR spectrometer for atmosphere monitoring
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Novel FTIR spectrometer for the monitoring of atmosphere is presented. Its design stands out by a compact form allowing the measures in two IR spectral bands 3-5 and 8-12 μm simultaneously. The spectrometer is composed of two Michelson interferometers with the joint sliding mirror. The paper contains the detailed description of the optics and electronics units, preliminary results of the measurement of biological aerosols and calibration methods.
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Content available remote Understanding the NEΔT of tactical infrared focal plane arrays
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NEΔT is the commonly used figure-of-merit for infrared-imaging systems using focal plane arrays (FPAs). This paper discusses an intuitive approach to understanding what determines this value in the majority of MWIR and LWIR broad-band applications, namely, the available charge storage capacity of the FPA readout. This conclusion is a consequence of the negligible amount of dark current compared to photo-current for modern detector technology.
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Content available Device for emissivity estimation in LWIR range
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The paper deals with the influence of emissivity on infrared measurements (Tab. 1; Fig. 1-3) and presents the developed device for emissivity estimation (Fig. 4). There is comparison shown between the reference emissivity values measured with thermal camera (Fig. 5) and estimated with the developed device (Tab. 2). Obtained results are in good agreement for three examined samples with emissivity ranging from 0.1 to 0.95.
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In this work the human detection method in infrared has been presented. The proposed solution focuses on the use low-level features and detecting parts of the human body. Low–level processing is based on modified HOG (Histogram of Oriented Gradients) algorithm. First, the only squared cells have been used, also calculation of the gradient has been improved. Next, the model of the head from the dataset IR (Infra Red) images has been created, also the model of the human body. Finally, the probability matrix has been examined using minimal distance classifier. The novelty of the proposed solution focuses on the combination of the pixel-gradient and body parts processing, also three stage classification process (head modelling, human modelling and classifier), which has been proposed to reduce the false detection. The experiments were performed on self-created IR images database, which contains images with most of the possible difficult situations such as overlapped people, different pose, small and high resolution of the people. The performance of the proposed algorithm was evaluated using Precision and Recall quality measure.
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Two new complexes [V(O)(sal-o-phdn)(H2O)] and [V(O)(sal-o-phdn)(C2H5OH)] (sal-o-phdn = N,N'-o-phenylenebis(salicylideneiminato)) have been synthesized and characterized by elemental and thermal analysis and electronic, infrared and Raman spectra. Both complexes are in the mononuclear forms where the Schiff base occupies the four equatorial positions and H2O or C2H5OH are axially coordinated to the vanadyl oxygen forming distorted octahedral with CS symmetry. The characteristic ni(V=O) vibrations for the mononuclears are observed at 978 and 981 cm-1 for the H2O and C2H5OH complexes, respectively. Full vibrational assignments for all observed bands are made. The vibrations of the coordinatedH2Oin [V(O)(sal-o-phdn)(H2O)] are observed at 3255, 1704, 829 and 645 cm-1 while those for the C2H5OH in [V(O)(sal-o-phdn)(C2H5OH)] are shown at 3620, 2950, 1386 and 860 cm-1.
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Content available Work on developing a thermal shooting target
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The paper presents work on the development of a thermal target providing for shooting with the use of night-vision and thermovision sights in night conditions as well as during the day, without changing the target. The image of the target in the night sight is visible by illuminating it through an IR lamp. The target is designed so that the reflected IR stream is directed towards the objective lens. Compared to existing solutions, the new thermal target has a number of advantages, such as it does not require long-time heating and is immediately ready to operate after thermal lamp lighting, significantly reducing energy consumption. The project is currently at the stage of prototype target testing.
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Content available remote InAs/GaSb superlattice focal plane arrays for high-resolution thermal imaging
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The first fully operational mid-IR (3–5 um) 256x256 IR-FPA camera system based on a type-II InAs/GaSb short-period superlattice showing an excellent noise equivalent temperature difference below 10 mK and a very uniform performance has been realized. We report on the development and fabrication of the detector chip, i.e., epitaxy, processing technology and electro-optical characterization of fully integrated InAs/GaSb superlattice focal plane arrays. While the superlattice design employed for the first demonstrator camera yielded a quantum efficiency around 30%, a superlattice structure grown with a thicker active layer and an optimized V/III BEP ratio during growth of the InAs layers exhibits a significant increase in quantum efficiency. Quantitative responsivity measurements reveal a quantum efficiency of about 60% for InAs/GaSb superlattice focal plane arrays after implementing this design improvement.
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Development of facial recognition or expression recognition algorithms requires input data to thoroughly test the performance of algorithms in various conditions. Researchers are developing various methods to face challenges like illumination, pose and expression changes, as well as facial disguises. In this paper, we propose and establish a dataset of thermal facial images, which contains a set of neutral images in various poses as well as a set of facial images with different posed expressions collected with a thermal infrared camera. Since the properties of face in the thermal domain strongly depend on time, in order to show the impact of aging, collection of the dataset has been repeated and a corresponding set of data is provided. The paper describes the measurement methodology and database structure. We present baseline results of processing using state-of-the-art facial descriptors combined with distance metrics for thermal face re-identification. Three selected local descriptors, a histogram of oriented gradients, local binary patterns and local derivative patterns are used for elementary assessment of the database. The dataset offers a wide range of capabilities - from thermal face recognition to thermal expression recognition.
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Inelastic incoherent neutron scattering spectra (IINS) were obtained for normal and deuterated L-proline. Raman and infrared spectra were also recorded. Geometries were optimized for the zwitterion form using ab initio Hartree-Fock (HF) level with 6-31G*, 6-311G** and 6-311++G** basis sets. Force fields and normal modes were calculated and used as basis for an assignment of the spectral features. The theoretical frequencies of normal and d2 - L-proline were compared with IINS spectra.
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Content available remote New frontiers for infrared
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Infrared (IR) science and technology has been mainly dedicated to surveillance and security: since the 70’s specialized techniques have been emerging in thermal imaging for medical and cultural heritage diagnostics, building and aeronautics structures control, energy savings and remote sensing. Most of these applications were developed thanks to IR FPAs sensors with high numbers of pixels and, actually, working at room temperatures. Besides these technological achievements in sensors/ receivers, advanced developments of IR laser sources up to far IR bands have been achieved in the form QCL (quantum cascade laser), allowing wide band TLC and high sensitivity systems for security. recently new sensors and sources with improved performances are emerging in the very far IR region up to submillimeter wavelengths, the so called terahertz (THz) region. A survey of the historical growth and a forecast of the future developments in Devices and Systems for the new frontier of IR will be discussed, in particular for the key questions: “From where and when is IR coming?”, “Where is it now?” and “Where will it go and when?”. These questions will be treated for key systems (Military/Civil), key devices (Sensors/ Sources), and new strategic technologies (Nanotech/TeraHertz).
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Materials that are difficult to cut possess excellent qualities and machinability, though conventional machining techniques require additional energy to circumvent the problems associated with the turning process. In this study, heat-assisted turning of duplex stainless steel (SS) was carried out. Various heating techniques such as infrared (IR)-, ultraviolet (UV)- and hot air(HA)-assisted heating were adopted. The experiment used an L16 orthogonal array with the most significant parameters such as heating method, feed rate in millimetres per revolution (mm/rev), depth of cut (millimetres [mm]) and cutting speed (metres per minute [m/min])on the cutting force and surface roughness. The technique for order performance by similarity to ideal solution (TOPSIS) and grey relational analysis (GRA), were used to optimise the output performance. The results of TOPSIS showed that the 16th experimental combination, i.e., the HA heating method, with feed rate = 0.175 mm/rev, depth of cut = 0.1 mm and cutting speed = 150 m/min, required a smaller cutting force and resulted in lower surface roughness. In case of the GRA method, the best output performance was observed for the 15th experimental combination, that is, the HA heating method, with feed rate = 0.15 mm/rev, depth of cut = 0.2 mm and cutting speed = 200 m/min. Compared to the non-heat-assisted turning process, the HA- and UV-assisted processes required 10.25% and 7.69% lesser cutting force, respectively, and the surface roughness in case of the HA method was 15.13% lesser.
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The article presents methods for identifying chemical compounds on the basis of their spectrums in Infrared. Specifically, transformation of the spectra from absorbing to transmitting ones and vice verse and calculation of the so-called base line and the maxima of the spectra are considered.
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Content available Real Time Thermal Imaging of Solid Oxide Fuel Cell
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In this work, a mid infrared thermography was used to study thermal behavior of solid oxide fuel cell (SOFC) with a circular shape and a diameter of 90 mm. The emissivity of the anodic surface of the fuel cell was determined to be from 0.95 to 0.46 in the temperature range 550-1200 K and the profile and temperature distribution of the anodic surface of the unloaded cell was given. The surface temperature of the cell was determined during operation and the polarity changes from open circuit voltage (OCV) to 0.0 V. It was found that the cell self-heating effect decreases with increasing temperature of the cell.
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Spoil tips are anthropomorphic terrain structures built out of leftover materials from underground or open pit mining. Usually the term spoil tips refers to those build out of unusable particles from coal exploration. As such they consist mostly of slate and various types of sandstone or mudstone. But also include some amount of coal and, what is more important, coal dust. Fires of spoil tips are dangerous to the environment and humans. They can cause degradation of air, and water qualities. Sometimes degradation to the environment can be irreversible. The presented survey was done in two stages. the first included creating a general terrain model. This was done with the use of long range laser scanner. The second step was a more detailed analysis of spatial and temperature conditions. Two measuring seasons ware performed. The first included a survey made with a short range laser scanner and a hand-held inferred camera. The obtained point cloud was supplemented with temperature value with the use of software and hardware provided by the authors. The visualization of 3D discreet thermal model was done in Bentley MicrioStation. The second included a usage of Z+F IMAGER 5010 laser scanner equipped with T-Cam Rev 1.0 thermal camera insole. A new and unique device that connects laser scanner with infrared camera. This season also provide a point cloud with attached temperature value of measured points. This article provides the description of those two methods including a comparison of their effectiveness and costs. It also describes the heat conditions occurring on spoil tip of Lubelski Węgiel „Bogdanka” S.A coal mine surveyed in December 2015.
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We consider new concepts of terahertz and infrared photodetectors based on multiple graphene layer and multiple graphene nanoribbon structures and we evaluate their responsivity and detectivity. The performance of the detectors under consideration is compared with that of photodetectors made of the traditional structures. We show that due to high values of the quantum efficiency and relatively low rates of thermogeneration, the graphene-based detectors can exhibit high responsivity and detectivity at elevated temperatures in a wide radiation spectrum and can substantially surpass other detectors. The detector being discussed can be used in different wide-band and multi-colour terahertz and infrared systems.
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