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| 2. |
- Engelbrecht, J. A. A., et al.
(författare)
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Notes on the plasma resonance peak employed to determine doping in SiC
- 2015
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Ingår i: Infrared physics & technology. - : ELSEVIER SCIENCE BV. - 1350-4495 .- 1879-0275. ; 72, s. 95-100
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Tidskriftsartikel (refereegranskat)abstract
- The doping level of a semiconductor material can be determined using the plasma resonance frequency to obtain the carrier concentration associated with doping. This paper provides an overview of the procedure for the three most common polytypes of SiC. Results for 3C-SiC are presented and discussed. In phosphorus doped samples analysed, it is submitted that the 2nd plasma resonance cannot be detected due to high values of the free carrier damping constant gamma. (C) 2015 Elsevier B.V. All rights reserved.
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| 3. |
- Haglund, Jesper, 1973-, et al.
(författare)
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Infrared cameras in science education
- 2016
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Ingår i: Infrared Physics & Technology. - : Elsevier BV. - 1350-4495 .- 1879-0275. ; 75, s. 150-152
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Tidskriftsartikel (refereegranskat)abstract
- Infrared cameras can be used in science education. The technology suits open-ended thermodynamics laboratory exercises in higher education. School children engage in instant inquiry of thermal phenomena.
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| 4. |
- Karimi, Mohammad, 1988-, et al.
(författare)
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Nanowire photodetectors with embedded quantum heterostructures for infrared detection
- 2019
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Ingår i: Infrared physics & technology. - Amsterdam : Elsevier. - 1350-4495 .- 1879-0275. ; 96, s. 209-212
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Tidskriftsartikel (refereegranskat)abstract
- Nanowires offer remarkable opportunities for realizing new optoelectronic devices because of their unique fundamental properties. The ability to engineer nanowire heterostructures with large bandgap variations is particularly interesting for technologically important broadband photodetector applications. Here we report on infrared photodetectors based on arrays of InP nanowires with embedded InAsP quantum discs. We demonstrate a strongly reduced dark current in the detector elements by compensating the unintentional n-doping in the nominal intrinsic region of the InP nanowires by in-situ doping with Zn, a crucial step towards realizing high-performance devices. The optimized array detectors show a broad spectral sensitivity at normal incidence for wavelengths from visible to far-infrared up to 20 μm, promoted by both interband and intersubband transitions. Optical simulations show that the unexpected normal incidence response at long wavelengths is due to non-zero longitudinal modes hosted by the nanowires. © 2018 Elsevier B.V.
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| 5. |
- Marx, G., et al.
(författare)
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Comments on a peak of AlxGa1-xN observed by infrared reflectance
- 2016
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Ingår i: Infrared physics & technology. - : ELSEVIER SCIENCE BV. - 1350-4495 .- 1879-0275. ; 76, s. 493-499
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Tidskriftsartikel (refereegranskat)abstract
- AlxGa1-xN epilayers, grown on c-plane oriented sapphire substrates by metal organic chemical vapour deposition (MOCVD), were evaluated using FTIR infrared reflectance spectroscopy. A peak at similar to 850 cm(-1) in the reflectance spectra, not reported before, was observed. Possible origins for this peak are considered and discussed. (C) 2016 Elsevier B.V. All rights reserved.
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| 6. |
- Ning, Yuping, et al.
(författare)
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Investigation on low thermal emittance of Al films deposited by magnetron sputtering
- 2016
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Ingår i: Infrared physics & technology. - : Elsevier BV. - 1350-4495 .- 1879-0275. ; 75, s. 133-138
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Tidskriftsartikel (refereegranskat)abstract
- A series of Al films with different thicknesses were deposited on polished stainless steel by direct current (DC) magnetron sputtering as a metal IR-reflector layer in solar selective absorbing coating (SSAC). The effects of the film thickness and the temperature on the thermal emittance of the Al films are studied. An optimal thickness 78 nm of the Al film for the lowest total thermal emittance is obtained. The thermal emittance of the optimal Al film keeps close to 0.02 from 25 degrees C to 400 degrees C, which are low enough to satisfy the optical requirements in SSAC. The optical constants of the AI film are deduced by fitting the reflectance and transmission spectra using SCOUT software.
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| 7. |
- Ning, Yuping, et al.
(författare)
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Tuning of reflectance transition position of Al-AlN cermet solar selective absorbing coating by simulating
- 2017
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Ingår i: Infrared physics & technology. - : Elsevier BV. - 1350-4495 .- 1879-0275. ; 80, s. 65-70
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Tidskriftsartikel (refereegranskat)abstract
- The reflectance spectra of the AI/double cermet Al-AIN/AIO(x)N(y) solar selective absorbing coating are simulated. Two methods have been found to effectively tune the position of reflectance transition of the Al-MN cermet solar selective absorbing coating, which is crucial to obtain a low emittance at elevated temperature. The position of reflectance transition is mainly determined by the high metal volume fraction (HMVF) cermet layer. It is effectively tuned to shift to lower wavelength by reducing the metal volume fraction or the thickness of the HMVF layer. This provides easy ways to tune the position of reflectance transition.
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| 8. |
- Pahlberg, Tobias, et al.
(författare)
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Crack detection in oak flooring lamellae using ultrasound-excited thermography
- 2018
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Ingår i: Infrared physics & technology. - : Elsevier. - 1350-4495 .- 1879-0275. ; 88, s. 57-69
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Tidskriftsartikel (refereegranskat)abstract
- Today, a large number of people are manually grading and detecting defects in wooden lamellae in the parquet flooring industry. This paper investigates the possibility of using the ensemble methods random forests and boosting to automatically detect cracks using ultrasound-excited thermography and a variety of predictor variables. When friction occurs in thin cracks, they become warm and thus visible to a thermographic camera. Several image processing techniques have been used to suppress the noise and enhance probable cracks in the images. The most successful predictor variables captured the upper part of the heat distribution, such as the maximum temperature, kurtosis and percentile values 92–100 of the edge pixels. The texture in the images was captured by Completed Local Binary Pattern histograms and cracks were also segmented by background suppression and thresholding. The classification accuracy was significantly improved from previous research through added image processing, introduction of more predictors, and by using automated machine learning. The best ensemble methods reach an average classification accuracy of 0.8, which is very close to the authors’ own manual attempt at separating the images (0.83).
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| 9. |
- Wäckelgård, Ewa, 1957-, et al.
(författare)
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Optical characterization and modelling of paint top-coatings for low-emittance applications
- 2016
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Ingår i: Infrared physics & technology. - : Elsevier BV. - 1350-4495 .- 1879-0275. ; 78, s. 275-281
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Tidskriftsartikel (refereegranskat)abstract
- The study reports on characterization of low-infrared-emittance paint top-coatings for interior building applications in which the thermal radiation becomes important in comparison with thermal conductance. The top-coating that consist of a binder with aluminium flakes has been optically characterized in the infrared wavelength range in order to determine single flake and binder emittance from reflectance measurements. The single flake emittance was found to be 0.12 for non-leafing cornflake. The absorption coefficient that determines the binder emittance as a function of binder thickness was 0.060 [μm]−2 and 0.085 [μm]−2 for Lumiflon and polyester respectively. These results were used as parameters in a simple model of the flake-binder top-coating to investigate how the emittance of the top-coating was influence by the two components and compared with a state-of-art low-emittance commercial paint. It was found from the modelling that replacing the polyester binder with Lumiflon reduces the infrared emittance (at room temperature) from 0.36 to 0.30. Increasing flake reflectance from 0.88 to 0.96 and at the same time reduce flake thickness from 2 to 1 μm gives an emittance of 0.20. However, the real samples prepared with Lumiflon showed a severe degradation caused by the flakes floating up closer to the surface which indicates a viscosity problem that needs to be solved for practical use. Thinner flakes with higher reflectance can be found if vacuum metallised pigments are used instead of ball-milled.
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| 10. |
- Bågesund, Mats, et al.
(författare)
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Dental care and oral health in Aagenaes syndrome/lymphedema cholestasis syndrome 1
- 2015
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Ingår i: Special Care in Dentistry. - : Wiley-Blackwell. - 0275-1879. ; 35:2, s. 83-89
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Tidskriftsartikel (refereegranskat)abstract
- Aagenaes syndrome/lymphedema cholestasis syndrome 1 (LCS1) is a rare genetic disorder characterized by neonatal cholestasis and lymphedema. The aim was to assess dental care and oral health in adults with LCS1. Fifteen (9M, 6F) individuals diagnosed with LCS1, aged 19-59 years participated. The study evaluated salivary secretion rate, dental radiographs, intraoral photos and included a questionnaire. Eight (53%) had regular dental checkups. Three had received subsidized dental care. Seven (47%) had two or more subjective symptoms of xerostomia. Three (20%) had a decreased stimulated salivary secretion rate below 0.7 mL/minute. Seven (47%) had dentin caries. Marginal periodontitis was found in all six patients above 35 years of age, but not before that age. Thirteen (87%) had tooth discoloration, which was extensive in three (20%). Conclusion. Several patients with LCS1 have problems with periodontitis and tooth discoloration. Frequent dental checkups are therefore recommended. © 2014 Special Care Dentistry Association and Wiley Periodicals, Inc.
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