Journal articles on the topic 'Partial transmittance optics'
To see the other types of publications on this topic, follow the link: Partial transmittance optics.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Partial transmittance optics.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Segtnan, V. H., and T. Isaksson. "Evaluating near Infrared Techniques for Quantitative Analysis of Carbohydrates in Fruit Juice Model Systems." Journal of Near Infrared Spectroscopy 8, no. 2 (March 2000): 109–16. http://dx.doi.org/10.1255/jnirs.270.
Full textAbstract:
Several techniques for measuring quality parameters in foods by the use of near infrared (NIR) technology have been reported. The aim of this experiment is to evaluate the main techniques in order to find the optimal measurement conditions for NIR analysis of carbohydrates in fluid food systems. Two different model systems were studied, each system containing 61 designed samples. The first system was designed to give scatter, and was based on a commercial orange juice. The other system was designed to be scatter-free, and was based on distilled water. To all samples were added the same total amounts of glucose, fructose and sucrose, and measured using the following NIR techniques: transmittance measurements in cuvettes, dry extract diffuse reflectance (DESIR), fibre-optic transflectance and fibre-optic transmittance. Calibration models were made by partial least squares regression in the spectral regions 780–2500nm for DESIR measurements, 1100–1315nm for 10mm pathlengths and 1100–1880+2130–2350nm for 1mm pathlengths. The models were fully cross-validated. Optimal prediction errors (Root Mean Square Error of Prediction, Cross-Validated) for DESIR measurements ranged from 0.020 to 0.030% (w/w), while 1mm cuvette values ranged from 0.008 to 0.012%. For these techniques there were only small differences between juice and water samples. Using fibre-optics, 1mm transmittance gave values in the range 0.068–0.081% for juice samples and 0.022–0.066% for water samples, while 1mm transflectance gave 0.044–0.051% for juice samples and 0.045–0.078% for water samples. 10mm pathlengths provided substantially higher prediction errors than 1mm for all techniques investigated. From these results, two main conclusions can be drawn. First, when measuring off-line, direct transmittance measurements in cuvettes gave better prediction results than DESIR. Second, when using fibre-optics, transflectance gave lower prediction errors than transmittance for scattering samples, while transmittance performed better than transflectance for non-scattering samples.
2
Chen, G., and C. L. Tien. "Partial Coherence Theory of Thin Film Radiative Properties." Journal of Heat Transfer 114, no. 3 (August 1, 1992): 636–43. http://dx.doi.org/10.1115/1.2911328.
Full textAbstract:
A new approach based on the partial coherent theory of light is introduced to predict the radiative properties of a thin film. General expressions obtained for the normal reflectance and transmittance of a thin film not only degenerate into the limiting results of the wave and the geometric optics in the coherent and incoherent cases, but also apply for all partial coherent states between the limits. The key element in the formulation is the complex degree of coherence, for which a general integral expression is obtained and further approximated algebraically for nearly monochromatic radiation. Limiting criteria and regime maps are established to demonstrate the range of applications for the various methods.
3
Li, Shijie, Chen Yang, Jin Zhang, Linpeng Dong, Changlong Cai, Haifeng Liang, and Weiguo Liu. "Tunable Optical Properties of Amorphous-Like Ga2O3 Thin Films Deposited by Electron-Beam Evaporation with Varying Oxygen Partial Pressures." Nanomaterials 10, no. 9 (September 6, 2020): 1760. http://dx.doi.org/10.3390/nano10091760.
Full textAbstract:
Ga2O3 thin films were fabricated by the electron-beam evaporation technique at a varying oxygen partial pressure from 0 to 2.0 × 10−2 Pa. The effect of oxygen partial pressure on the crystalline structure and optical properties of the Ga2O3 films was analyzed using sophisticated techniques including X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, spectroscopic ellipsometry, ultraviolet-visible spectroscopy and a laser-induced damage test system. The correlation between the oxygen partial pressure and the film’s properties in optics and materials were investigated. XRD and Raman revealed that all films were amorphous in spite of applying a varying oxygen partial pressure. With the change of oxygen partial pressure, XPS data indicated that the content of oxygen in the Ga2O3 films could be broadly modulable. As a result, a changeable refractive index of the Ga2O3 film is realizable and a variable blue-shift of absorption edges in transmittance spectra of the films is achievable. Moreover, the damage threshold value varied from 0.41 to 7.51 J/cm2 according to the rise of oxygen partial pressure. These results demonstrated that the optical properties of Ga2O3 film can be broadly tunable by controlling the oxygen content in the film.
4
Lazarova, Katerina, Silvia Bozhilova, Sijka Ivanova, Darinka Christova, and Tsvetanka Babeva. "Flexible and Transparent Polymer-Based Optical Humidity Sensor." Sensors 21, no. 11 (May 25, 2021): 3674. http://dx.doi.org/10.3390/s21113674.
Full textAbstract:
Thin spin-coated polymer films of amphiphilic copolymer obtained by partial acetalization of poly (vinyl alcohol) are used as humidity-sensitive media. They are deposited on polymer substrate (PET) in order to obtain a flexible humidity sensor. Pre-metallization of substrate is implemented for increasing the optical contrast of the sensor, thus improving the sensitivity. The morphology of the sensors is studied by surface profiling, while the transparency of the sensor is controlled by transmittance measurements. The sensing behavior is evaluated through monitoring of transmittance values at different levels of relative humidity gradually changing in the range 5–95% and the influence of up to 1000 bending deformations is estimated by determining the hysteresis and sensitivity of the flexible sensor after each set of deformations. The successful development of a flexible sensor for optical monitoring of humidity in a wide humidity range is demonstrated and discussed.
5
Hamdy, Omnia, Zienab Abdel-Salam, and Mohamed Abdel-Harith. "Optical Characterization of Biological Tissues Based on Fluorescence, Absorption, and Scattering Properties." Diagnostics 12, no. 11 (November 17, 2022): 2846. http://dx.doi.org/10.3390/diagnostics12112846.
Full textAbstract:
Optical diagnostics methods are significantly appealing in biological applications since they are non-destructive, safe, and minimally invasive. Laser-induced fluorescence is a promising optical spectrochemical analytical technique widely employed for tissue classification through molecular analysis of the studied samples after excitation with appropriate short-wavelength laser light. On the other hand, diffuse optics techniques are used for tissue monitoring and differentiation based on their absorption and scattering characteristics in the red to the near-infrared spectra. Therefore, it is strongly foreseen to obtain promising results by combining these techniques. In the present work, tissues under different conditions (hydrated/dry skin and native/boiled adipose fat) were distinguished according to their fluorescence emission, absorption, and scattering properties. The selected tissues’ optical absorption and scattering parameters were determined via Kubelka–Munk mathematical model according to the experimental tissue reflectance and transmittance measurements. Such measurements were obtained using an optical configuration of integrating sphere and spectrometer at different laser wavelengths (808, 830, and 980 nm). Moreover, the diffusion equation was solved for the fluence rate at the sample surface using the finite element method. Furthermore, the accuracy of the obtained spectroscopic measurements was evaluated using partial least squares regression statistical analysis with 0.87 and 0.89 R-squared values for skin and adipose fat, respectively.
6
Hong, Suk-Ju, Shin-Joung Rho, Ah-Yeong Lee, Heesoo Park, Jinshi Cui, Jongmin Park, Soon-Jung Hong, Yong-Ro Kim, and Ghiseok Kim. "Rancidity Estimation of Perilla Seed Oil by Using Near-Infrared Spectroscopy and Multivariate Analysis Techniques." Journal of Spectroscopy 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/1082612.
Full textAbstract:
Near-infrared spectroscopy and multivariate analysis techniques were employed to nondestructively evaluate the rancidity of perilla seed oil by developing prediction models for the acid and peroxide values. The acid, peroxide value, and transmittance spectra of perilla seed oil stored in two different environments for 96 and 144 h were obtained and used to develop prediction models for different storage conditions and time periods. Preprocessing methods were applied to the transmittance spectra of perilla seed oil, and multivariate analysis techniques, such as principal component regression (PCR), partial least squares regression (PLSR), and artificial neural network (ANN) modeling, were employed to develop the models. Titration analysis shows that the free fatty acids in an oil oxidation process were more affected by relative humidity than temperature, whereas peroxides in an oil oxidation process were more significantly affected by temperature than relative humidity for the two different environments in this study. Also, the prediction results of ANN models for both acid and peroxide values were the highest among the developed models. These results suggest that the proposed near-infrared spectroscopy technique with multivariate analysis can be used for the nondestructive evaluation of the rancidity of perilla seed oil, especially the acid and peroxide values.
7
Zhang, Chu, Chang Wang, Fei Liu, and Yong He. "Mid-Infrared Spectroscopy for Coffee Variety Identification: Comparison of Pattern Recognition Methods." Journal of Spectroscopy 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/7927286.
Full textAbstract:
The potential of using mid-infrared transmittance spectroscopy combined with pattern recognition algorithm to identify coffee variety was investigated. Four coffee varieties in China were studied, including Typica Arabica coffee from Yunnan Province, Catimor Arabica coffee from Yunnan Province, Fushan Robusta coffee from Hainan Province, and Xinglong Robusta coffee from Hainan Province. Ten different pattern recognition methods were applied on the optimal wavenumbers selected by principal component analysis loadings. These methods were classified as highly effective methods (soft independent modelling of class analogy, support vector machine, back propagation neural network, radial basis function neural network, extreme learning machine, and relevance vector machine), methods of medium effectiveness (partial least squares-discrimination analysis,Knearest neighbors, and random forest), and methods of low effectiveness (Naive Bayes classifier) according to the classification accuracy for coffee variety identification.
8
Xiong, Yating, Shintaroh Ohashi, Kazuhiro Nakano, Weizhong Jiang, Kenichi Takizawa, Kazuyuki Iijima, and Phonkrit Maniwara. "Quantification of potassium concentration with Vis–SWNIR spectroscopy in fresh lettuce." Journal of Innovative Optical Health Sciences 13, no. 06 (October 28, 2020): 2050029. http://dx.doi.org/10.1142/s1793545820500297.
Full textAbstract:
Chronic kidney disease (CKD) is becoming a major public health problem worldwide, and excessive potassium intake is a health threat to patients with CKD. In this study, visible–short-wave near-infrared (Vis–SWNIR) spectroscopy and chemometric algorithms were investigated as nondestructive methods for assessing the potassium concentration in fresh lettuce to benefit the CKD patients’ health. Interactance and transmittance measurements were performed and the competencies were compared based on the multivariate methods of partial least-square regression (PLS) and support vector machine regression (SVR). Meanwhile, several preprocessing methods [first- and second-order derivatives in combination with standard normal variate (SNV)] and wavelength selection method of competitive adaptive reweighted sampling (CARS) were applied to eliminate noise and highlight the spectral characteristics. The PLS models yielded better prediction than the SVR models with higher correlation coefficients ([Formula: see text]) and residual predictive deviation (RPD), and lower root-mean-square error of prediction (RMSEP). Excellent prediction of green leaves was obtained by the interactance measurement with [Formula: see text], [Formula: see text][Formula: see text]mg/100[Formula: see text]g, and [Formula: see text]; while the transmittance spectra of petioles provided optimal prediction with [Formula: see text], [Formula: see text][Formula: see text]mg/100[Formula: see text]g, and RPD[Formula: see text]=[Formula: see text]3.34, respectively. Therefore, the results indicated that Vis–SWNIR spectroscopy is capable of intelligently detecting potassium concentration in fresh lettuce to benefit CKD patients around the world in maintaining and enhancing their health.
9
Hakobyan, Armen V. "Aperture shapes and the effectiveness of ground-based large and extremely large telescopes." Monthly Notices of the Royal Astronomical Society 496, no. 4 (July 21, 2020): 5414–22. http://dx.doi.org/10.1093/mnras/staa1792.
Full textAbstract:
ABSTRACT Aperture shapes in modern large and forthcoming extremely large telescopes (ELTs), with effective light-gathering sizes more than D ∼ 10 m, differ significantly from the desirable circular one. They deliver specific point spread functions, which may also differ notably from that of the fine structure of the classical Airy pattern. The optical power of such a telescope can be changed notably compared with a circular aperture with the same area. The presence of atmospheric optical turbulence complicates the effect additionally and makes it seeing- and wavelength-dependent. So, what is the impact of a non-circular pupil on telescope exploitation? It concerns the efficiency, which is an important point, especially for instruments of such a class. In this research an attempt is made to assess the values of these changes in the context of the Keck, HDRT, GMT, TMT and ELT telescopes. Relative performance characteristics (integral contrast and signal-to-noise ratio, S/N) of the telescopes, working in the seeing-limited regime, under a range of plausible turbulence conditions, for a wide (from UV to mid-IR) spectral region are obtained. The partial role of central obscuration is assessed. The effect of adaptive optics implementation in this context is also analysed. It is shown that, for instance, maximal S/N degradation due to the non-circularity of the pupil shape can be as much as $\sim 6~{{\ \rm per\ cent}}$ (TMT) to $30~{{\ \rm per\ cent}}$ (HDRT), depending on the telescope and observational mode. The numbers are comparable with or may even substantially exceed the losses that could be caused by the other parameters (e.g. residual wave-front error, optical transmittance) relevant to the quality of the optical system.
10
Hsu, Jin-Cherng, and Yu-Yun Chen. "Comparison of the Optical and Electrical Properties of Al-Doped ZnO Films Using a Lorentz Model." Coatings 9, no. 1 (December 21, 2018): 4. http://dx.doi.org/10.3390/coatings9010004.
Full textAbstract:
In this research, zinc oxide (ZnO) films are doped with various amounts of Al dopants, from 0 to 13 at.%, using ion-beam co-sputtering for Zn and Al metallic targets at room temperature. The Al-doped ZnO (AZO) films appear to have lower transmittances in the UV and near-IR ranges. The electrical and optical properties of each film are successfully analyzed by using the spectroscopic ellipsometry of two Lorentz oscillators for the two lower transmittances. The optimal AZO film is deposited with an Al-dopant of 1.5 at.% at an oxygen partial pressure of 0.12 mTorr; it has the smallest resistivity of 7.8 × 10−4 Ω cm and high transmittance of > 80% in the visible regions. The free carrier concentration and mobility evaluated using ellipsometry are different from those measured using the Hall effect. This phenomenon was the result of the grain boundary scattering due to the small ~20-nm grain size of the AZO film used in this study.
11
Nicolaus, M., C. Petrich, S. R. Hudson, and M. A. Granskog. "Variability of light transmission through Arctic land-fast sea ice during spring." Cryosphere 7, no. 3 (June 20, 2013): 977–86. http://dx.doi.org/10.5194/tc-7-977-2013.
Full textAbstract:
Abstract. The amount of solar radiation transmitted through Arctic sea ice is determined by the thickness and physical properties of snow and sea ice. Light transmittance is highly variable in space and time since thickness and physical properties of snow and sea ice are highly heterogeneous on variable time and length scales. We present field measurements of under-ice irradiance along transects under undeformed land-fast sea ice at Barrow, Alaska (March, May, and June 2010). The measurements were performed with a spectral radiometer mounted on a floating under-ice sled. The objective was to quantify the spatial variability of light transmittance through snow and sea ice, and to compare this variability along its seasonal evolution. Along with optical measurements, snow depth, sea ice thickness, and freeboard were recorded, and ice cores were analyzed for chlorophyll a and particulate matter. Our results show that snow cover variability prior to onset of snow melt causes as much relative spatial variability of light transmittance as the contrast of ponded and white ice during summer. Both before and after melt onset, measured transmittances fell in a range from one third to three times the mean value. In addition, we found a twentyfold increase of light transmittance as a result of partial snowmelt, showing the seasonal evolution of transmittance through sea ice far exceeds the spatial variability. However, prior melt onset, light transmittance was time invariant and differences in under-ice irradiance were directly related to the spatial variability of the snow cover.
12
Srivastava, Satyam, Abhai Tiwari, Pankaj Kumar, and Shashikant Sadistap. "A Multispectral Spectroscopic Based Sensing System for Quality Parameters Measurement in Raw Milk Samples." Sensor Letters 18, no. 4 (April 1, 2020): 311–21. http://dx.doi.org/10.1166/sl.2020.4222.
Full textAbstract:
Lactometer is used to monitor milk quality at various dairy centers but this may lead towards incorrect results because it requires human intervention and exact temperature correction as well as overall process is time-consuming. Presented work proposes the multispectral based spectroscopic approach along with the comparative study of different chemometric and artificial neural network (ANN) based techniques to measure different milk quality parameters. A multispectral spectroscopic sensing module has been designed using off the shelf components and further interfaced with 8-bit microcontroller based embedded system to produce three different spectrums of transmittance and scattering at +90 degree and –90 degree over the wavelength range of 340–1030 nm. Data acquisition process has been performed for 150 milk samples (cow, buffalo, and mix) collected from the bulk milk cooling center (BMC), Jaipur. Different statistical modeling techniques such as principle component regression (PCR), multiple linear regression (MLR) and partial least square regression (PLSR) have been implemented to develop correlation models between extracted features and target milk parameters. Implemented techniques have been compared based on the accuracy of their prediction models and it has been observed that PLSR shows better results compared to other two techniques. ANN-based modeling approach also has been explored to improve the accuracy of results. Five different artificial neural networks (ANN) based modeling techniques (LevenbergMarquardt, Bayesian regulation, scaled conjugate gradient, gradient descent and resilient) have been used to predict targeted milk quality parameters. Out of them, Gradient descent modeling technique performs better to predict fat content of the milk (R2 = 0.96198), Bayesian regulation performs better to predict lactose content (R2 = 0.90594) and others (solid non-fat (SNF), protein) are just satisfactory (R2 = 0.76077 for SNF using scaled conjugate gradient, R2 = 0.41935 for protein using Levenberg Marquardt). Produced results are validated with the MilkoScan FT1 system installed at Rajasthan Corporation of Dairy Federation (RCDF), Jaipur and it has been observed that results presented higher order of coefficient of determination as mentioned above (except protein, S.N.F.). A smartphone-based android application also has been developed to acquire data from the embedded system using Bluetooth protocol and transfer to cloud with the location information for further analysis.
13
Braun, Paul J., Thomas B. Givens, Andrew G. Stead, Lisa R. Beck, Sheila A. Gooch, Robert J. Swan, and Timothy J. Fischer. "Properties of Optical Data from Activated Partial Thromboplastin Time and Prothrombin Time Assays." Thrombosis and Haemostasis 78, no. 03 (1997): 1079–87. http://dx.doi.org/10.1055/s-0038-1657690.
Full textAbstract:
SummaryChanges in characteristics of optical transmittance data from coagulation assays were examined as a function of concentration of coagulation proteins or anticoagulants. Transmittance data were collected for activated partial thromboplastin time (APTT) and prothrombin time (PT) assays from: 1) plasmas prepared by mixing normal plasmas with deficient plasmas to give varying levels of coagulation proteins; 2) plasmas containing added heparin; and 3) 200 specimen plasmas that were also assayed for fibrinogen, coagulation factors, and other components. Optical profiles were characterized using a set of parameters describing onset and completion of coagulation, magnitude of signal change, rate of coagulation and other properties. Results indicated that parameters other than those typically reported for APTT and PT are associated with individual deficiencies, but that diagnosis of specimen status on the basis of optical data is complex. These results suggest possibilities for expanded interpretation of PT/APTT optical data for clinical or research applications.
14
Huang, Ren Gui, Dong Ping Zhang, Ting Zhang, Yan Li, You Tong Chen, Yong Lin Zhong, and Ping Fan. "Properties of Vanadium Oxide Films Prepared by DC Reactive Magnetron Sputtering at Different Oxygen Partial Pressures." Advanced Materials Research 538-541 (June 2012): 105–9. http://dx.doi.org/10.4028/www.scientific.net/amr.538-541.105.
Full textAbstract:
Due to their unique physical and chemical properties, vanadium oxide thin films have become a hot research topic. In the present work, Vanadium oxide thin films were prepared by DC reactive magnetron sputtering at different oxygen partial pressure and thermally annealed in Ar atmosphere at 500°C for 2 hours. The microstructure, transmittance, optical band gap, resistivity, and temperature coefficient resistance (TCR) were measured. The results suggest that increasing of oxygen partial pressure can obviously improve the optical and electric properties
15
Shigetoshi, Yasuhiro, Susumu Tsukimoto, Hidehisa Takeda, Kazuhiro Ito, and Masanori Murakami. "Electrical Properties and Microstructures of Ultraviolet Transparent Ga2O3 Thin Films." Materials Science Forum 561-565 (October 2007): 1233–36. http://dx.doi.org/10.4028/www.scientific.net/msf.561-565.1233.
Full textAbstract:
The electrical and optical properties, and microstructures of 100 nm-thick Ga2O3 films fabricated on Al2O3(0001) substrates by a sputtering deposition were investigated. The partial pressure of oxygen was controlled and the substrate temperature was kept to be 500 °C during deposition. With increasing the oxygen partial pressure, the structures of the Ga2O3 films deposited on the substrates were observed to change from amorphous to crystalline (monoclinic β-type Ga2O3). The transmittance of the Ga2O3 films was measured to be more than 80 % at the visible and ultraviolet regions although the electrical resistivity was high. In order to obtain both low electrical resistivity and high transmittance at the ultraviolet regions, the addition of active dopant elements such as Sn into the Ga2O3 films would be required.
16
Grado-Caffaro, M. A., and M. Grado-Caffaro. "Calculation of the optical transmittance in cadmium oxide by considering oxygen plasma." Journal of Research in Physics 39, no. 1 (June 1, 2018): 65–74. http://dx.doi.org/10.2478/jrp-2018-0006.
Full textAbstract:
Abstract By considering the partial pressure of oxygen in the deposition process of cadmium oxide, we calculate the maximum transmittance of cadmium oxide in the visible range, which is achieved at the so-called optimum partial pressure of oxygen, this value of pressure being a key figure of merit. Our formulation agrees with experimental measurements and is consistent with the so-called plasma-optical effect. At this point, an exhaustive evaluation of previous experimental data is performed by doing a detailed comparison among the results from different authors and by performing numerical estimations (including estimations from experimental data) of relevant physical quantities. In fact, a comprehensive discussion relative to comparison between experimental measurements and our theoretical results is presented.
17
KRISHNA, M. GHANASHYAM, and A. K. BHATTACHARYA. "OPTICAL AND ELECTRICAL PROPERTIES OF VANADIUM NITRIDE THIN FILMS." International Journal of Modern Physics B 13, no. 07 (March 20, 1999): 833–39. http://dx.doi.org/10.1142/s0217979299000692.
Full textAbstract:
Vanadium nitride thin films have been deposited on to quartz substrates by dc magnetron sputtering at two different total pressures and a series of nitrogen partial pressures. The spectral transmittance of these films, in the region 350 to 1500 nm, is strongly dependent on the nitrogen partial pressure during sputtering and relatively insensitive to total pressure. The films became more transparent as the nitrogen partial pressure was decreased at a constant total pressure. The optical constants, refractive index and extinction coefficient, exhibited a similar dependence on the nitrogen partial pressure. The sheet resistivity of the films decreased with increasing nitrogen partial pressure. The values of resistivity indicate that the films are semiconducting rather than metalic.
18
Lapić, Ivana, Ana Lončar Vrančić, Désirée Coen Herak, and Dunja Rogić. "The missing slope: paradoxical shortening of activated partial thromboplastin time in a patient on unfractionated heparin therapy." Biochemia medica 31, no. 2 (June 15, 2021): 372–76. http://dx.doi.org/10.11613/bm.2021.021003.
Full textAbstract:
This case report describes false shortening of activated partial thromboplastin time (aPTT) due to erroneous optical reading of the clotting point in the presence of unfractionated heparin (UFH), and a biphasic waveform. Activated partial thromboplastin time performed on a coagulometer with photo-optical detection yielded an ambiguous clotting curve characterized by an early and steady decrease in light transmittance throughout the whole measuring range, with the clotting point read at 65 seconds. Further investigations included measurement of aPTT by means of a mechanical clot detection method as well as determination of another heparin-sensitive coagulation assay, that is thrombin time (TT), both being unmeasurably prolonged (> 150 seconds). Communication with clinicians revealed that the patient was on continuous UFH therapy and had an underlying sepsis, with highly elevated C-reactive protein (289 mg/L). The aPTT measurements requested at three timepoints later during the same day revealed gradual aPTT shortening and unveiled a peculiar biphasic waveform pattern. In this case, unmeasurably prolonged aPTT due to UFH therapy was masked by a biphasic aPTT curve pattern making only the first slope of the biphasic waveform visible within the measuring range. The early decrease in plasma light transmittance mimicked optical changes related to clot formation, thus causing erroneous optical reading and yielding a falsely shortened aPTT. This case emphasizes that such a pattern should be carefully inspected, especially when a combination of a critically ill condition and UFH therapy is present, in order to prevent erroneous reporting of aPTT and potential adverse effects on patient care.
19
Chandra Sekhar, M., P. Kondaiah, B. Radha Krishna, and S. Uthanna. "Effect of Oxygen Partial Pressure on the Electrical and Optical Properties of DC Magnetron Sputtered AmorphousTiO2Films." Journal of Spectroscopy 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/462734.
Full textAbstract:
Titanium dioxide (TiO2) thin films were deposited on p-Si (100) and Corning glass substrates held at room temperature by DC magnetron sputtering at different oxygen partial pressures in the range9×10−3–9×10−2 Pa. The influence of oxygen partial pressure on the structural, electrical, and optical properties of the deposited films was systematically studied. XPS studies confirmed that the film formed at an oxygen partial pressure of6×10−2 Pa was nearly stoichiometric. TiO2films formed at all oxygen partial pressures were X-ray amorphous. The optical transmittance gradually increased and the absorption edge shifted towards shorter wavelengths with the increase of oxygen partial pressure. Thin film capacitors with configuration of Al/TiO2/p-Si have been fabricated. The results showed that the leakage current density of films formed decreased with the increase of oxygen partial pressure to6×10−2Pa owing to the decrease in the oxygen defects in the films thereafter it was increased. The current transport mechanism in the TiO2thin films is shown to be Schottky effect and Fowler-Nordheim tunnelling currents.
20
Madhavi, V., P. Kondaiah, O. M. Hussain, and S. Uthanna. "Structural, Optical, and Luminescence Properties of Reactive Magnetron Sputtered Tungsten Oxide Thin Films." ISRN Optics 2012 (December 1, 2012): 1–8. http://dx.doi.org/10.5402/2012/801468.
Full textAbstract:
Tungsten oxide (WO3) thin films were deposited on to unheated Corning glass and silicon substrates by RF magnetron sputtering of metallic tungsten target at various oxygen partial pressures in the range 4×10-2–1×10-1 Pa. The influence of oxygen partial pressure on the structure and surface morphology and the optical and photoluminescence properties of the films were investigated. X-ray diffraction studies revealed that the deposited films were amorphous in nature. Fourier transform infrared transmission spectra confirmed that the presence of stretching vibration of W-O-W and deformation of W-O bonds related to the WO3. The optical transmittance of the films at wavelengths >500 nm increased from 62% to 85% with the increase of oxygen partial pressure. The optical band gap of the films increased from 3.00 to 3.14 eV and the refractive index of the films decreased from 2.26 to 2.08 with the increase of oxygen partial pressure from 4×10−2 to 1×10−1 Pa, respectively. The photoluminescence studies indicated that the intense blue emission which was assigned to band-to-band transition was observed at oxygen partial pressure of 6×10−2 Pa.
21
Nicolaus, M., C. Petrich, S. R. Hudson, and M. A. Granskog. "Variability of light transmission through Arctic land-fast sea ice during spring." Cryosphere Discussions 6, no. 5 (October 12, 2012): 4363–85. http://dx.doi.org/10.5194/tcd-6-4363-2012.
Full textAbstract:
Abstract. The amount of solar radiation transmitted through Arctic sea ice is determined by the thickness and physical properties of snow and sea ice. Light transmittance is highly variable in space and time since thickness and physical properties of snow and sea ice are highly heterogeneous on variable time and length scales. We present field measurements of under-ice irradiance along repeated (March, May, June 2010) transects under un-deformed land-fast sea ice at Barrow, Alaska. The objective was to quantify seasonal evolution and spatial variability of light transmittance through snow and sea ice. Along with optical measurements, snow depth, sea ice thickness, and freeboard were recorded, and ice cores were analyzed for Chlorophyll a and particulate matter. Our results show that snow cover variability prior to onset of snow melt may cause as much spatial variability of relative light transmittance as the contrast of ponded and white ice during summer. In both instances, a spatial variability of up to three times above and below the mean was measured. In addition, we found a thirtyfold increase of light transmittance as a result of partial snowmelt. Hence, the seasonal evolution of transmittance through sea ice exceeded the spatial variability. Nevertheless, more comprehensive under-ice radiation measurements are needed for a more generalized and large-scale understanding of the under-ice energy budget for physical, biological, and geochemical applications.
22
Yang, Xian Ming, Lin Liu, and Juan Xiu Lin. "A Study of ITO Thin Films Fabricated by DC Magnetron Sputtering Method." Advanced Materials Research 834-836 (October 2013): 79–89. http://dx.doi.org/10.4028/www.scientific.net/amr.834-836.79.
Full textAbstract:
With high optical transparency and electrical conductivity, ITO thin films were fabricated by DC magnetron sputtering. Based on orthogonal test table L18 (35), the effects of process parameters included water partial pressure, work pressure, substrate temperature, oxygen flow rate and sputtering power, on the optoelectronics properties of ITO thin films were investigated in detail(systematically). Calibration of sheet resistance transmittance, atomic force microscope, and X-ray diffraction were employed to characterize the ITO films.
23
Tang Xiaohong, 唐晓红, 黄美东 Huang Meidong, 杜姗 Du Shan, 刘春伟 Liu Chunwei, 高倩 Gao Qian, 王小龙 Wang Xiaolong, 张建鹏 Zhang Jianpeng, and 杨明敏 Yang Mingmin. "Influence of Oxygen Partial Pressure on Structure and Optical Transmittance of Sputtered Vanadium Oxide Films." Laser & Optoelectronics Progress 51, no. 6 (2014): 063101. http://dx.doi.org/10.3788/lop51.063101.
Full text
24
Rehman, Irfa, Muhammad Bilal Hanif, Abdulaziz Salem Alghamdi, Abdul Khaliq, K. S. Abdel Halim, Tayyab Subhani, Martin Motola, and Abdul Faheem Khan. "Intrinsic Properties of Multi-Layer TiO2/V2O5/TiO2 Coatings Prepared via E-Beam Evaporation." Materials 15, no. 11 (May 31, 2022): 3933. http://dx.doi.org/10.3390/ma15113933.
Full textAbstract:
Nanocomposite multi-layer TiO2/V2O5/TiO2 thin films were prepared via electron-beam evaporation using high-purity targets (TiO2 and V2O5 purity > 99.9%) at substrate temperatures of 270 °C (TiO2) and 25 °C (V2O5) under a partial pressure of oxygen of 2 × 10−4 mbar to maintain the stoichiometry. Rutherford backscattering spectrometry was used to confirm the layer structure and the optimal stoichiometry of the thin films, with a particle size of 20 to 40 nm. The thin films showed an optical transmittance of ~78% in the visible region and a reflectance of ~90% in the infrared. A decrease in transmittance was observed due to the greater cumulative thickness of the three layers and multiple reflections at the interface of the layers. The optical bandgap of the TiO2 mono-layer was ~3.49 eV, whereas that of the multi-layer TiO2/V2O5/TiO2 reached ~3.51 eV. The increase in the optical bandgap was due to the inter-diffusion of the layers at an elevated substrate temperature during the deposition. The intrinsic, structural, and morphological features of the TiO2/V2O5/TiO2 thin films suggest their efficient use as a solar water heater system.
25
Aleksandrova, Mariya, Tatyana Ivanova, Kostadinka Gesheva, Velichka Strijkova, Tsvetozar Tsanev, Jai Singh, and Ajaya Kumar Singh. "Fabrication of Transparent ITO/Ga-Doped ZnO Coating as a Front Panel Electrode toward Efficient Thin Film Solar Cells." Materials Proceedings 2, no. 1 (May 13, 2020): 1. http://dx.doi.org/10.3390/ciwc2020-06831.
Full textAbstract:
Bi-layer coatings from sputtered indium tin oxide (ITO) and gallium doped zinc oxide (Ga:ZnO) were investigated for transparency in the visible range of the electromagnetic spectrum, optical rejection ability in the near infrared spectrum and conductivity for the novel quantum dot-based solar cells. The multilayer stack produced at optimal oxygen partial pressure exhibits improved optical properties without worsening the electrical ones, even after additional oxidation during the reactive sputtering of the metal-oxides. With a mean optical transmittance of 91.3% in the visible region, mean optical rejection greater than 65% in the infrared range and resistivity lower than 0.4 × 10−2 Ω.cm, this coating is good candidate for front panel electrode in the CdS/ZnS core-shell quantum dot-based solar cells.
26
MAGID, Hayim Ch,, Intesar Hato HASHIM, and Kadhim A. AADIM. "INFLUENCE OF LASER ENERGY ON CDS NANO PARTIALS PREPARED BY LASER INDUCED PLASMA." MINAR International Journal of Applied Sciences and Technology 03, no. 03 (September 1, 2021): 69–76. http://dx.doi.org/10.47832/2717-8234.3-3.9.
Full textAbstract:
In this work ,cadmium sulfide (CdS) thin films deposited on glass substrates using Nd-YAG laser wavelength (1064 nm) laser-induced plasma deposition technique (PLD). The structural, morphology and optical properties of these films have been described as a change in the effect of laser pulse energy ( ). The X-ray diffraction results show that s all samples were polycrystalline hexagonal structure and the crystalline size ghange with increasing of the laser energy. The optical properties results show that the transmittance of all deposited thin films decreases with increasing of laser pulse energy .As a result of the microscopic examination of the surface, it was found that the surface is uniform and the granular size increases with the increase of the laser power.
27
Geçici, Birol, Şadan Korkmaz, Soner Özen, Volkan Şenay, and Suat Pat. "Influence of oxygen partial pressure on the metastable copper oxide thin films." Modern Physics Letters B 30, no. 35 (December 20, 2016): 1530012. http://dx.doi.org/10.1142/s0217984915300124.
Full textAbstract:
Paramelaconite (Cu4O3) is a metastable copper oxide. Metastable copper oxide thin films were deposited on glass substrates by reactive RF magnetron sputtering in argon (Ar) and oxygen (O2) gas mixture atmospheres. Ar/O2 gas ratios in the sputtering ambient were chosen as 1/1 and 1/9. The surface and optical properties were determined by X-ray diffractometer (XRD), atomic force microscope (AFM) and UV-Vis spectrophotometer. The XRD patterns of the samples exhibited single strong diffraction peaks at 35.39[Formula: see text] and 35.49[Formula: see text], corresponding to the (202) peak of Cu4O3. The mean thickness values were measured as 100 nm and 80 nm for the films deposited at 1/1 and 1/9 Ar/O2 gas ratios, respectively. The samples showed low transmittance and high absorbance in the high frequency region.
28
CHEN, Y., J. C. ZHOU, B. X. ZHAO, and J. J. SUN. "SPUTTERED TiO2 FILMS FOR PHOTOVOLTAIC CELL'S ANTIREFLECTION COATING." International Journal of Nanoscience 11, no. 01 (February 2012): 1250008. http://dx.doi.org/10.1142/s0219581x12500081.
Full textAbstract:
TiO2 films were prepared by the magnetron sputter system with various oxygen partial pressure ratios, for the application of photovoltaic (PV) cells, TiO2 single-layer and SiO2/TiO2 double-layer antireflection (AR) coatings were deposited on Si substrate. The experimental results indicate that TiO2 film deposited at oxygen partial pressure ratio of 15.4% exhibits smooth surface morphology, amorphous structure, and good optical transmittance, which is suitable for AR coating in the PV cell structure system. Furthermore, the weighted average reflectance in the range of 400–900 nm was about 10.3% and 3.7% for the TiO2 single-layer and SiO2/TiO2 double-layer AR coatings, respectively. With a double-layer AR coating, a 50.8% improvement in the efficiency of a Si PV cell was achieved.
29
Balasundraprabhu, Rangasamy, N. Muthukumarasamy, E. V. Monakhov, and B. G. Svensson. "Structural, Optical and Morphological Studies on Nanostructure ITO Thin Films." Advanced Materials Research 678 (March 2013): 140–43. http://dx.doi.org/10.4028/www.scientific.net/amr.678.140.
Full textAbstract:
Indium tin oxide (ITO) thin films exhibiting good transmittance and conductivity suitable for solar cell applications have been prepared on Si(100) and fused silica substrates by optimizing the dc sputtering parameters such as power density and Ar partial pressure. Structural analysis of the as-deposited and annealed ITO films indicated that the as-deposited films are predominantly amorphous, whereas the films annealed at 200–400 °C are found to be of polycrystalline nature exhibiting dominant peaks corresponding to the (222) and (400) planes. The optical transmittance and band gap values of the films are observed to exhibit a change on annealing. From the ellipsometry studies on ITO/Si annealed at 300°C, it is found that graded layer consist of the mixing of two ITO materials with slightly different optical constants and the grading is almost linear. The resistivity of the ITO films is found to decrease with annealing temperature, correlating with the improvement in the crystal quality, and values in the range of 2-3 x10-4 Ω-cm are observed for the films annealed at 300°C. Surface topography study of the films has been performed using atomic force microscope(AFM) and the results are discussed.
30
Thonglem, Sutatip, Chavalit Suksri, Kamonpan Pengpat, Gobwute Rujijanagul, Sukum Eitssayeam, Uraiwan Intatha, and Tawee Tunkasiri. "Tuning the Band Gap of ZnO Thin Films by Mg Doping." Key Engineering Materials 690 (May 2016): 131–36. http://dx.doi.org/10.4028/www.scientific.net/kem.690.131.
Full textAbstract:
Structural, morphological, optical and electrical properties of magnesium (Mg) doped zinc oxide (ZnO) films prepared by ultrasonic spray pyrolysis technique on microscope glass substrate, have been studied in terms of Mg doping content. The precursors solutions of Mg doped ZnO films were prepared from zinc acetate dihydrate (Zn (CH3OO)2⋅2H2O) and magnesium acetate tetrahydrate (CH3COO)2Mg⋅4H2O) acted as dopant. The compositions of these solutions were fixed at 0.02 M of Zn (CH3OO)2.2H2O and the atomic percentage ratio of Mg/Zn was varied from 0 to 20 atomic %. The XRD pattern of all films showed ZnO hexagonal wurtzite structure and the morphology showed homogeneous structure/texture and pinhole-free with adding Mg content. It was found that Mg2+ ions do not change conductivity of ZnO films due to the partial substitution of Zn2+ ion by the same valence Mg2+ ion. For optical properties, all films showed high transmittance over 80% and absorbance about 0.01 in visible and near infrared regions. Moreover, the Mg dopant affects on a shift of the absorption edge in transmittance spectra of the films to a lower wavelength in ultraviolet region and increases the band gap of the samples.
31
Schneider, K. "Structural And Optical Properties Of VOx Thin Films." Archives of Metallurgy and Materials 60, no. 2 (June 1, 2015): 957–61. http://dx.doi.org/10.1515/amm-2015-0238.
Full textAbstract:
Abstract VOx thin films were deposited on Corning glass, fused silica and Ti foils by means of rf reactive sputtering from a metallic vanadium target. Argon-oxygen gas mixtures of different compositions controlled by the flow rates were used for sputtering. Influence of the oxygen partial pressure in the sputtering chamber on the structural and optical properties of thin films has been investigated. Structural properties of as-sputtered thin films were studied by X-ray diffraction at glancing incidence, GIXD. Optical transmittance and reflectance spectra were recordedwith a Lambda 19 Perkin-Elmer double spectrophotometer. Thickness of the films was determined from the profilometry. It has been confirmed by XRD that the deposited films are composed mainly of V2O5 phase. The estimated optical band gap of 2.5 eV corresponds to V2O5.
32
LAI, GUOZHONG, YANGWEI WU, LIMEI LIN, YAN QU, and FACHUN LAI. "OPTICAL PROPERTIES OF N-DOPED Cu2O THIN FILMS DEPOSITED BY RF-MAGNETRON SPUTTERING Cu2O TARGET." Surface Review and Letters 21, no. 04 (August 2014): 1450052. http://dx.doi.org/10.1142/s0218625x14500528.
Full textAbstract:
N -doped Cu 2 O films were deposited on quartz substrates by reactive magnetron sputtering a Cu 2 O target. The optical constants and thicknesses of the films with different nitrogen partial pressure (NPP) were retrieved from transmittance data by an optical model which combines the Forouhi–Bloomer model with modified Drude model. The results show that when NPP increases from 0.0 to 0.033 Pa, the optical gap decreases from 2.14 to 1.95 eV. Additionally, an optical absorption process in the infrared region below the optical band gap was observed for N -doped Cu 2 O films, which was not found in the pure Cu 2 O film. This is because an intermediate band (IB) in the band gap results from nitrogen doping. It is believed that N -doped Cu 2 O film with suitable NPP could be used to enhance the energy conversion efficiency for photovoltaic cells.
33
SHAO, LE-XI, JUN ZHANG, SHU-WEN XUE, and XIAO-PING LIU. "PREPARATION AND CHARACTERIZATION OF F-DOPED SnO2 NANO-THIN FILMS DEPOSITED ON PET SUBSTRATES." International Journal of Nanoscience 08, no. 01n02 (February 2009): 157–61. http://dx.doi.org/10.1142/s0219581x0900592x.
Full textAbstract:
Tin oxide doped with fluorine ( SnO 2: F ) thin films were deposited on polyethylene terephthalate (PET) foils by RF reaction cosputtering at low temperature in different oxygen partial pressures. X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) were used to study the effects of the processing parameters on the crystallization and surface topography of the as-prepared SnO 2 films. The results showed that high quality SnO 2: F thin films could be obtained by optimizing deposition conditions without intentional annealing, i.e. oxygen partial pressure to total pressure of higher than 50%, RF power higher than 50 W. The optical transmittance measurements revealed that the SnO 2: F films were highly transparent in the visible region (90%) and showed an absorption edge redshift with increasing oxygen partial pressure from 1/4 to 3/4. The optical bandgap energy was calculated to be about 3.6 eV. Hall effect measurements confirmed that the as-prepared SnO 2 thin films possessed good electrical properties with a low resistivity of 10-3 Ω · cm, a high carrier concentration of 9.6 × 1018 cm-3, and a Hall mobility of about 200 cm2/V · s.
34
Cemmi, A., A. Colangeli, B. D'orsi, I. Di Sarcina, E. Diociaiuti, S. Fiore, D. Paesani, et al. "Radiation study of Lead Fluoride crystals." Journal of Instrumentation 17, no. 05 (May 1, 2022): T05015. http://dx.doi.org/10.1088/1748-0221/17/05/t05015.
Full textAbstract:
Abstract Lead fluoride (PbF2) crystals represent an excellent and relatively innovative choice for high resolution electromagnetic calorimeters with high granularity and fast timing for high intensity environments. For this reason two PbF2 crystals, sized 5× 5 × 40 mm3, were irradiated with 60Co photons up to ∼ 4 Mrad and with 14 MeV neutrons up to a 1013 n/cm2 total fluence. Their loss in transmittance was evaluated at different steps of the photon and neutron irradiation campaign, resulting in a total of 30% loss above 350 nm. With crystals always kept in dark conditions, natural and thermal annealing, as well as optical bleaching with 400 nm light, were performed on the irradiated specimens, resulting in a partial recovery of their original optical characteristics.
35
Lazarova, Katerina, Silvia Bozhilova, Sijka Ivanova, Darinka Christova, and Tsvetanka Babeva. "Moisture-Responsive Polymer Films on Flexible Substrates for Optical Sensing of Humidity." Engineering Proceedings 2, no. 1 (November 14, 2020): 19. http://dx.doi.org/10.3390/ecsa-7-08182.
Full textAbstract:
In this paper, the possibility to design flexible humidity sensors by spin-coating ofmoisture-sensitive polymer on three types of substrates—poly(ethylene terephthalate) (PET),polylactide (PLA) and composite polysiloxane is investigated. The optical properties, surfacemorphology and roughness of the substrates covered with polymer are studied by transmittancemeasurements and surface profiling, respectively. Thin polymer films of amphiphilic copolymerobtained by partial acetalization of poly(vinyl alcohol) are used as humidity sensitive media. Thesensing properties are probed through transmittance measurements at different levels of relativehumidity (RH). The influence of substrate type is studied by comparing the hysteresis of flexiblesensors with those that are deposited on glass substrates.
36
Lehman, M. "Diffraction by a Fractal Transmittance Obtained from a Multiplicative Superposition of Periodical Rectangular Functions." Fractals 06, no. 04 (December 1998): 313–26. http://dx.doi.org/10.1142/s0218348x98000377.
Full textAbstract:
The Fraunhofer region of one-dimensional fractal diffraction grating is studied when this grating is defined using a set of scaled periodical (and rectangular) functions. The fractal structure is obtained through a Cantor density function, which is defined from an incremental product of such periodical components. Each of these components can be filtered individually and so, the corresponding intensity pattern can be evaluated. A mathematical foundation for such decomposition is developed using the concept of characteristic (or indicator) function of a set. Graphic results are shown and the partial self-similarity of lateral intensity distribution calculated in any transversal plane to the optical axis for a certain value of magnification. With these results, fractal, periodical and intrinsic periodical domains can be distinguished to characterize the intensity patterns. The self-similarity of intensity distributions and the contrast of that function are calculated for different states of the Cantor transmittance.
37
Kim, Hyun Hoo, Moo Young Lee, Kwang Tae Kim, and Sahng Hyun Yoon. "Transparent Conducting ITO Films Reactively Sputtered on Polyethylene Terephtalate Substrates Without Heat Treatment." International Journal of Modern Physics B 17, no. 08n09 (April 10, 2003): 1242–47. http://dx.doi.org/10.1142/s0217979203018818.
Full textAbstract:
Indium tin oxide (ITO) films have been deposited on PET and glass substrates by DC reactive magnetron sputtering without post-deposition thermal treatment. High quality films have been deposited by optimizing the sputtering parameters. The influence of the working gas pressure, DC power, and oxygen partial pressure has been investigated. The lowest resistivity of ITO films deposited on PET substrates was 6×10-4Ωcm. It has been obtained at a working pressure of 3 mTorr and DC power of 30 W. The sheet resistance and optical transmittance of these films were 22 Ω/square and 84%, respectively. The best values of figures of merit for the electrical and optical chardcteristics such as T / R sh and T 10/ R sh are approximately 38.1 and 7.95 (×10-3 Ω-1), respectively.
38
Krishna, K. Hari, O. M. Hussain, and C. Guillen. "Photo- and Electrochromic Properties of Activated Reactive EvaporatedMoO3Thin Films Grown on Flexible Substrates." Research Letters in Nanotechnology 2008 (2008): 1–5. http://dx.doi.org/10.1155/2008/217510.
Full textAbstract:
The molybdenum trioxide (MoO3) thin films were grown onto ITO-coated flexible Kapton substrates using plasma assisted activated reactive evaporation technique. The film depositions were carried out at constant glow power and oxygen partial pressures of 8 W and1×10−3Torr, respectively. The influence of substrate temperature on the microstructural and optical properties was investigated. TheMoO3thin films prepared at a substrate temperature of 523 K were found to be composed of uniformly distributed nanosized grains with an orthorhombic structure ofα-MoO3. These nanocrystallineMoO3thin films exhibited higher optical transmittance of about 80% in the visible region with an evaluated optical band gap of 3.29 eV. With the insertion of 12.5 mC/cm2, the films exhibited an optical modulation of 40% in the visible region with coloration efficiency of 22 cm2/C at the wavelength of 550 nm. TheMoO3films deposited at 523 K demonstrated better photochromic properties and showed highest color center concentration for the irradiation time of 30 minutes at 100 mW/cm2.
39
Wahab, Md A., Mohammad R. Karim, Muhammad O. Aijaz, Bidita Salahuddin, Shazed Aziz, and Abu A. I. Sina. "A Study on the Interfacial Compatibility, Microstructure and Physico-Chemical Properties of Polyimide/Organically Modified Silica Nanocomposite Membrane." Polymers 13, no. 8 (April 18, 2021): 1328. http://dx.doi.org/10.3390/polym13081328.
Full textAbstract:
Polyimide-silica (PI-Silica) composites are of tremendous research interest as high-performance materials because of their excellent thermal and mechanical properties and chemical resistance to organic solvents. Particularly, the sol-gel method of fabricating such composites is popular for manipulating their properties. In this work, PI-silica composite films are synthesized by the sol-gel method and thermal imidization from the solution mixtures of hydrolyzed tetraethoxysilane (TEOS) (or glycidoxypropyltrimethoxysilane (GPMS)) modified silica and an aromatic polyamic acid (PAA) based on 3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA)–p-phenylenediamine (PDA). The phase morphology of composites is found to be controlled by the substitution of TEOS with GPMS. Solid-state NMR spectroscopy is used to confirm the structural components of silica and GPMS-modified silica, whereas FT-IR results confirm the complete imidization of polyimide and composite film and suggest successful incorporation of Si–O–Si bonds into polyimide. The thermal, optical transmittance, and dielectric constant characterizations of pure polyimide and composite films are also carried out. Thermal stability of pure polyimide is found to be increased significantly by the addition of silica, whereas the partial substitution of TEOS with GPMS decreases the thermal stability of the composite, due to the presence of the alkyl organic segment of GPMS. The optical transmittance and dielectric constant of the composite films are controlled by manipulating the GPMS content.
40
Leng, Jin Feng, Li Na Chen, Xiao Zhe Zhu, and Zhen He Sun. "Structure and Photoelectric Properties of Cu3N Thin Films by Reactive Magnetron Sputtering." Materials Science Forum 814 (March 2015): 620–24. http://dx.doi.org/10.4028/www.scientific.net/msf.814.620.
Full textAbstract:
Cu3N thin films can potentially be used for development of optical storage devices and integrate circuit of semiconductor. In this study the Cu3N films were deposited on glass substrate successfully by reactive direct current magnetron sputtering at different N2/(N2+Ar) flow ratio. The results showed that the nitrogen partial pressure affected the preferring orientation of the thin films when the sputtering power and substrate temperature was fixed. With increasing N2/(N2+Ar) flow ratio from 10% to 90%, Cu3N(111) orientation with rich-copper changed to Cu3N(100) orientation with rich nitrogen, the transmittance of the thin films improved gradually, and the corresponding optical band gap (Eg) increased from 1.10 eV to 1.21eV. The resistivity of copper nitrogen films changed from 5.62Ω.cm to 3.00×103Ω.cm at the scope of 10%~90% of N2/(N2+Ar) flow ratio.
41
Aleksandrova, Mariya, Tatyana Ivanova, Velichka Strijkova, Tsvetozar Tsanev, Ajaya Kumar Singh, Jai Singh, and Kostadinka Gesheva. "Ga-Doped ZnO Coating—A Suitable Tool for Tuning the Electrode Properties in the Solar Cells with CdS/ZnS Core-Shell Quantum Dots." Crystals 11, no. 2 (January 29, 2021): 137. http://dx.doi.org/10.3390/cryst11020137.
Full textAbstract:
Two layer system from sputtered indium tin oxide (ITO) and gallium doped zinc oxide (Ga:ZnO, GZO) were studied for transparency in the visible electromagnetic range, reflectivity in the near infrared range, conductivity and valent band for a solar cells with quantum dots. The bi-layer coatings produced at optimized oxygen partial pressure, films thickness and surface roughness exhibit improved optical properties without worsening the electrical parameters, even if additional oxygen introduction during the reactive sputtering of the GZO. With an average optical transmittance of 91.3% in the visible range, average reflection and resistivity lower than 0.4 × 10−2 Ω.cm, these coatings are suitable for top electrode in the solar cells. The obtained results reveal that multilayered stacks of transparent ITO/Ga-doped ZnO coatings possess relatively low surface roughness (7–9 nm) and appropriate refractive index. The additional oxidation of GZO films induces modification of the film thickness and respectively of their optical performances.
42
Peiris, K. H. S., G. G. Dull, R. G. Leffler, and S. J. Kays. "Near-infrared (NIR) Spectrometric Technique for Nondestructive Determination of Soluble Solids Content in Processing Tomatoes." Journal of the American Society for Horticultural Science 123, no. 6 (November 1998): 1089–93. http://dx.doi.org/10.21273/jashs.123.6.1089.
Full textAbstract:
A nondestructive method for measuring the soluble solids content (SSC) of individual processing tomatoes (Lycopersicon esculentum Mill.) was developed using NIR spectrometry. A diode array fiber optic spectrometer was used to measure NIR transmittance. Each fruit was scanned at two locations on opposite sides midway along the proximal-distal axis. After scanning, each fruit was processed and pureed, and SSC was determined using a refractometer. Multiple linear regression (MLR), partial least squares (PLS) regression, and neural network (NN) calibration models were developed using the second derivatives of averaged spectra from 780 to 980 nm. The validation results showed that NN calibration was better than MLR or PLS calibrations. The NN calibration could estimate the processed SSC of individual unprocessed tomatoes with a standard error of prediction of 0.52% and could classify >72% of fruit in an independent population within ±0.5% of SSC.
43
Chen, Hongye, Min Li, Xiaoyan Wen, Yingping Yang, Daping He, Wallace Choy, and Haifei Lu. "Enhanced Silver Nanowire Composite Window Electrode Protected by Large Size Graphene Oxide Sheets for Perovskite Solar Cells." Nanomaterials 9, no. 2 (February 2, 2019): 193. http://dx.doi.org/10.3390/nano9020193.
Full textAbstract:
Despite the outstanding features of high transmittance and low sheet resistance from silver nanowire (Ag NW) based transparent electrodes, their applications in perovskite solar cells (PVSCs) as window electrodes encounter significant obstacles due to the stability issue brought by the corrosion of halogen species from perovskite layer. In this study, we used large size graphene oxide (LGO) sheets as the protective barrier for bottom Ag NW nano-network. Contributed by the LGO with average size of 60 μm, less GO sheet was necessary for forming the fully covered protective barrier with fewer cracks, which consequently improved the optical transparency and anticorrosive ability of the composite electrode compared to the one from relatively small size GO. Our experiments demonstrated the composite electrode of Ag NW/LGO. The glass substrate exhibited transmittance of 83.8% and 81.8% at 550 nm before and after partial reduction, which maintained 98.4% and 95.1% average transmittance (AVT) of the pristine Ag NW electrode. Meanwhile, we utilized the steady hot airflow to assist the fast solvent evaporation and the uniform GO film formation on Ag NW electrode. Before the application of composite electrode in organic-inorganic hybrid perovskite solar cells, the operational stability of composite electrodes from different sizes of GO with perovskite film fabricated on top were characterized under continuing external bias and light irradiation. Experimental results indicate that the Ag NW electrode protected by LGO could maintain original resistance for more than 45 h. Finally, the PVSC fabricated on Ag NW/LGO based composite electrode yielded a power conversion efficiency (PCE) of 9.62%, i.e., nearly 85% of that of the reference device fabricated on the commercial indium-tin oxide (ITO) glass. Our proposed low temperature and solution processed bottom electrode with improved optical transparency and operational stability can serve as the very beginning layer of optoelectronic devices, to promote the development of low cost and large area fabrication perovskite solar cells.
44
Thanimkan, R., B. Namnuan, and S. Chatraphorn. "Fabrication of SnO2 by RF magnetron sputtering for electron transport layer of planar perovskite solar cells." Journal of Physics: Conference Series 2145, no. 1 (December 1, 2021): 012027. http://dx.doi.org/10.1088/1742-6596/2145/1/012027.
Full textAbstract:
Abstract The requirements of electron transport layer (ETL) for high efficiency Perovskite solar cells (PSCs) are, for example, appropriate band energy alignment, high electron mobility, high optical transmittance, high stability, and easy processing. SnO2 has attracted more attention as ETL for PSCs because it has diverse advantages, e.g., wide bandgap energy, excellent optical and chemical stability, high transparency, high electron mobility, and easy preparation. The SnO2 ETL was fabricated by RF magnetron sputtering technique to ensure the chemical composition and uniform layer thickness when compared to the use of chemical solution via spin-coating method. The RF power was varied from 60 - 150 W. The Ar sputtering gas pressure was varied from 1 × 10−3 - 6 × 10−3 mbar while keeping O2 partial pressure at 1 × 10−4 mbar. The thickness of SnO2 layer decreases as the Ar gas pressure increases resulting in the increase of sheet resistance. The surface morphology and optical transmission of the SnO2 ETL were investigated. It was found that the optimum thickness of SnO2 layer was approximately 35 - 40 nm. The best device shows Jsc = 27.4 mA/cm2, Voc = 1.03 V, fill factor = 0.63, and efficiency = 17.7%.
45
Kim, Jihyung, Jongmin Park, and Sungjun Kim. "Bipolar Switching Characteristics of Transparent WOX-Based RRAM for Synaptic Application and Neuromorphic Engineering." Materials 15, no. 20 (October 15, 2022): 7185. http://dx.doi.org/10.3390/ma15207185.
Full textAbstract:
In this work, we evaluate the resistive switching (RS) and synaptic characteristics of a fully transparent resistive random-access memory (T-RRAM) device based on indium-tin-oxide (ITO) electrodes. Here, we fabricated ITO/WOX/ITO capacitor structure and incorporated DC-sputtered WOX as the switching layer between the two ITO electrodes. The device shows approximately 77% (including the glass substrate) of optical transmittance in visible light and exhibits reliable bipolar switching behavior. The current-voltage (I–V) curve is divided into two types: partial and full curves affected by the magnitude of the positive voltage during the reset process. In the partial curve, we confirmed that the retention could be maintained for more than 104 s and the endurance for more than 300 cycles could be stably secured. The switching mechanism based on the formation/rupture of the filament is further explained through the extra oxygen vacancies provided by the ITO electrodes. Finally, we examined the responsive potentiation and depression to check the synaptic characteristics of the device. We believe that the transparent WOX-based RRAM could be a milestone for neuromorphic devices as well as future non-volatile transparent memory.
46
Zhang, Lei, Liang Heng Wang, Ming Kai Li, Xun Zhong Shang, and Yun Bin He. "Structural and Optical Properties of ZnO1-xSx Thin Films Grown by Pulse Laser Deposition on Glass Substrates." Materials Science Forum 787 (April 2014): 18–22. http://dx.doi.org/10.4028/www.scientific.net/msf.787.18.
Full textAbstract:
With a wide band gap of 3.4 eV and a large exciton binding energy of 60 meV at room temperature, ZnO is attractive for blue and ultra-violet optoelectronic devices, and transparent conducting oxide films for photovoltaic applications. For a semiconductor to be useful, particularly in reference to optoelectronic devices, band gap engineering is of great importance in device development. Alloying of MgO and CdO with ZnO has been studied extensively in comparison to other ZnO alloys incorporating equivalent anions like ZnO1-xSx (ZnOS). In this work, high-quality ZnOS thin films were grown on glass substrates by pulsed laser deposition using a ZnS ceramic target with varying O2 partial pressures between 0 and 6 Pa. ZnOS alloys with a wurtzite structure were achieved and no evident phase separation was observed in the whole composition range as determined by X-ray diffraction. The optical transmission measurements show that the average transmittance in the visible range of the films is about 80%. The absorption edges of the films first shift towards low-energy side with increasing the oxygen partial pressure and then blueshift when the oxygen partial pressure is over 2 Pa. The bandgap energies of the ZnOS films were calculated to change from 3.06 to 3.72 eV, showing a nonlinear variation with a bowing behavior that was previously reported.
47
POKAIPISIT, ARTORN, NITINAI UDOMKAN, and PICHET LIMSUWAN. "NANOSTRUCTURE AND PROPERTIES OF INDIUM TIN OXIDE (ITO) FILMS PRODUCED BY ELECTRON BEAM EVAPORATION." Modern Physics Letters B 20, no. 17 (July 30, 2006): 1049–58. http://dx.doi.org/10.1142/s0217984906011402.
Full textAbstract:
Nanocrystal indium tin oxide (ITO) thin films were grown by electron beam evaporation (e-beam). The ITO films were fabricated at substrate temperatures ranging from 100 to 400°C in O 2 partial pressure ranging from 0.10 to 100 mTorr. The surface morphology was monitored using atomic force microscopy (AFM). The charge in the surface morphology of ITO films was discussed in terms of grain size and crystallographic orientations. Grain size measurements of the solid dispersed and the AFM study for nanostructure showed that the oxides were in the nano range (20–30 nm). In general, the values of the optical bandgap for the films are consistently blue-shifted as compared with the crystal size. The average crystalline size determined from the shift of the optical gap were found to be in the range 20–30 nm, which is in excellent agreement with the data obtained from AFM. All ITO films average grain size was ~ 20 nm deposited by e-beam evaporation. The average optical transmittance was 90.50% in the visible range (400–700 nm) and the average bandgap was 3.98 eV. ESR spectrum of ITO film showed random oxygen vacancies which arise due to the changing crystal field effects.
48
Guthrie, J. A., C. J. Liebenberg, and K. B. Walsh. "NIR model development and robustness in prediction of melon fruit total soluble solids." Australian Journal of Agricultural Research 57, no. 4 (2006): 411. http://dx.doi.org/10.1071/ar05123.
Full textAbstract:
Near infrared spectroscopy (NIRS) can be used for the on-line, non-invasive assessment of fruit for eating quality attributes such as total soluble solids (TSS). The robustness of multivariate calibration models, based on NIRS in a partial transmittance optical geometry, for the assessment of TSS of intact rockmelons (Cucumis melo) was assessed. The mesocarp TSS was highest around the fruit equator and increased towards the seed cavity. Inner mesocarp TSS levels decreased towards both the proximal and distal ends of the fruit, but more so towards the proximal end. The equatorial region of the fruit was chosen as representative of the fruit for near infrared assessment of TSS. The spectral window for model development was optimised at 695–1045 nm, and the data pre-treatment procedure was optimised to second-derivative absorbance without scatter correction. The ‘global’ modified partial least squares (MPLS) regression modelling procedure of WINISI (ver. 1.04) was found to be superior with respect to root mean squared error of prediction (RMSEP) and bias for model predictions of TSS across seasons, compared with the ‘local’ MPLS regression procedure. Updating of the model with samples selected randomly from the independent validation population demonstrated improvement in both RMSEP and bias with addition of approximately 15 samples.
49
Kang, Myoungsuk, and Jiwan Kim. "A Study on the ZnO Thin Film Deposited by RF Sputtering Method as an Electron Transport Layer in Quantum Dot Light-Emitting Diodes." Korean Journal of Metals and Materials 59, no. 10 (October 5, 2021): 718–23. http://dx.doi.org/10.3365/kjmm.2021.59.10.730.
Full textAbstract:
We report a highly efficient quantum dot light emitting diode (QLEDs) with a radio frequency (RF) sputtered ZnO thin film as an electron transport layer (ETL) instead of the conventional ZnO nanoparticles (NPs) by solution process. ZnO NPs have been used as a key material to improve the performance of QLEDs, but the charge imbalance in ZnO NPs resulting from fast electron injection, and their limited uniformity are significant disadvantages. In this study, ZnO layers were deposited by RF sputtering with various O2 partial pressures. All of the ZnO films showed preferential growth along the (002) direction, smooth morphology, and good optical transmittance. To test their feasibility for QLEDs, we fabricated devices with RF sputtered ZnO layers as an ETL, which has the inverted structure of ITO/RF sputtered ZnO/QDs/CBP/MoO3/Al. The optical/electrical characteristics of two devices, comprised of RF sputtered ZnO and ZnO NPs, were compared with each other. QLEDs with the sputtered ZnO ETL achieved a current efficiency of 11.32 cd/A, which was higher than the 8.23 cd/A of the QLEDs with ZnO NPs ETL. Next, to find the optimum ZnO thin film for highly efficient QLEDs, deposition conditions with various O2 partial pressures were tested, and device performance was investigated. The maximum current efficiency was 13.33 cd/A when the ratio of Ar/O2 was 4:3. Additional oxygen gas reduced the O vacancies in the ZnO thin film, which resulted in a decrease in electrical conductivity, thereby improving charge balance in the emission layer of the QLEDs. As a result, we provide a way to control the ZnO ETL properties and to improve device performance by controlling O2 partial pressure.
50
Kang, Myoungsuk, and Jiwan Kim. "A Study on the ZnO Thin Film Deposited by RF Sputtering Method as an Electron Transport Layer in Quantum Dot Light-Emitting Diodes." Korean Journal of Metals and Materials 59, no. 10 (October 5, 2021): 718–23. http://dx.doi.org/10.3365/kjmm.2021.59.10.718.
Full textAbstract:
We report a highly efficient quantum dot light emitting diode (QLEDs) with a radio frequency (RF) sputtered ZnO thin film as an electron transport layer (ETL) instead of the conventional ZnO nanoparticles (NPs) by solution process. ZnO NPs have been used as a key material to improve the performance of QLEDs, but the charge imbalance in ZnO NPs resulting from fast electron injection, and their limited uniformity are significant disadvantages. In this study, ZnO layers were deposited by RF sputtering with various O2 partial pressures. All of the ZnO films showed preferential growth along the (002) direction, smooth morphology, and good optical transmittance. To test their feasibility for QLEDs, we fabricated devices with RF sputtered ZnO layers as an ETL, which has the inverted structure of ITO/RF sputtered ZnO/QDs/CBP/MoO3/Al. The optical/electrical characteristics of two devices, comprised of RF sputtered ZnO and ZnO NPs, were compared with each other. QLEDs with the sputtered ZnO ETL achieved a current efficiency of 11.32 cd/A, which was higher than the 8.23 cd/A of the QLEDs with ZnO NPs ETL. Next, to find the optimum ZnO thin film for highly efficient QLEDs, deposition conditions with various O2 partial pressures were tested, and device performance was investigated. The maximum current efficiency was 13.33 cd/A when the ratio of Ar/O2 was 4:3. Additional oxygen gas reduced the O vacancies in the ZnO thin film, which resulted in a decrease in electrical conductivity, thereby improving charge balance in the emission layer of the QLEDs. As a result, we provide a way to control the ZnO ETL properties and to improve device performance by controlling O2 partial pressure.