Transmittance Ratio Research Articles

Methodical Aspects of Determination of Parameters Which Characterize Thermal Balance of a Plastic Tunnel

Abstract The paper presents methodology of measuring the values which characterize the thermal balance in a horticultural facility. Thermal transmittance through a plastic tunnel cover and the ratio of solar radiation energy conversion into heat were analysed in detail. The research was carried out in real time with closed ventilators, where no plants were cultivated during the tests. The utility surface area was 144 m2, the cover was 289 m2 and its volume was 508 m3. Basing on the standard relations, first of all, thermal transmittance through a cover was measured. The ratio was measured with the use of standard criteria equations. Then, a correlation equation, which makes its course dependent on the climate parameters (the wind speed and temperature difference between the interior of the facility and its surroundings), was found. Knowing the course of the ratio in the function of the climate parameters, the value of the ratio of solar radiation conversion into heat stored in the facility was measured. Both parameters (thermal transmittance and solar radiation conversion ratios) were calculated from the thermal balance equaition where the change of the energy stored inside the facility was compared to the heat losses through a cover (for thenual transmittance) and the profit (in case of solar radiation conversion). For the obtained values, using the non-linear estimation procedure (with quasi-Newtom method with maintenance of the correlation coefficient of 0.001) the change of both ratios in the function of easily measured parameters of climate inside and outside the facility was found out. In the investigated conditions, the average value of thermal transmittance through a cover was 5.32 W·m−2·K−1, and the solar radiation conversion into heat was 0.36. The values and their course from the climate parameters inside and outside the facility may be used for controlling the amount of supplied heat and location of ventilators.

Diode laser-based standoff absorption measurement of water film thickness in retro-reflection

A dual-wavelength diode laser-based absorption sensor for standoff point measurements of water film thickness on an opaque surface is presented. The sensor consists of a diode laser source, a foil as backscattering target, and off-axis paraboloids for collecting the fraction of the laser radiation transmitted through the liquid layer via retro-reflection. Laser wavelengths in the near infrared at 1412 and 1353 nm are used where the temperature dependence of the liquid water absorption cross section is known. The lasers are fiber coupled and the detection of the retro-reflected light was accomplished through a multimode fiber and a single photodiode using time-division multiplexing. The water film thickness at a given temperature was determined from measured transmittance ratios at the two laser wavelengths. The sensor concept was first validated with measurement using a temperature-controlled calibration cell providing liquid layers of variable and known thickness between 100 and 1000 µm. Subsequently, the sensor was demonstrated successfully during recording the time-varying thickness of evaporating water films at fixed temperatures. The film thickness was recorded as a function of time at three temperatures down to 50 µm.

Kinetics on the turbidity change of wheat starch during its retrogradation.

Wheat starch dispersions of 10-40% (w/w) were gelatinized and the change in turbidity of each solution during storage was measured in the 400-1100nm wavelength range. The relative transmittance, defined as the ratio of transmittance at any storage time to that at the initial time, decreased when the solutions were stored at 5 and 30°C; the decrease, reflecting the progress of retrogradation, was larger at 5°C than at 30°C. Most of the changes in relative transmission taking place over 14days were achieved during the first 90min. The change in the relative transmittance is inversely proportional to the energy required for deformation. The kinetics on change in relative transmittance can be expressed by Weibull equation. The larger rate constant at higher starch concentration could be ascribed to the state of the starch granules, which depended on starch concentration.

Optical analysis of solar collector with new V-shaped CPC

Compound parabolic concentrators (CPC) with tubular absorbers are widely used in solar thermal systems because they can achieve the highest concentration without tracking system. Reducing the gap loss is important for utilization of the concentrators. This paper proposes a model with new V-shaped profile at the bottom of the reflector according edge ray principle and established the model, discusses this model about relative concentrating ratio and gap efficiency. A detailed model of the optical efficiency for the solar collector with inner CPC is built, analyzes the parameters of the model, such as geometrical optics efficiency, transmittance, reflectance and absorption ratio, with methods of ray tracing and geometrical optics. For Accurate analysis, the optical efficiency is divided into the beam and diffuse optical efficiency, and incidence angle radial is divided into incidence angle and axial incidence angle, then analyzes optical efficiency of the designed CPC based on the model, concludes how to select the model in accordance with the size of the gap, and proves CPC with the new V-shaped profile has a good prospect.

Micro-light-pipe array with an excitation attenuation filter for lensless digital enzyme-linked immunosorbent assay

Digital enzyme-linked immunosorbent assay (ELISA) is used for detecting various biomarkers with hypersensitivity. We have been developing compact systems by replacing the fluorescence microscope with a CMOS image sensor. Here, we propose a micro-light-pipe array structure made of metal filled with dye-doped resin, which can be used as a fabrication substrate of the micro-reaction-chamber array of digital ELISA. The possibility that this structure enhances the coupling efficiency for fluorescence was simulated using a simple model. To realize the structure, we fabricated a 30-µm-thick micropipe array by copper electroplating around a thick photoresist pattern. The typical diameter of each fabricated micropipe was 10 µm. The pipes were filled with yellow-dye-doped epoxy resin. The transmittance ratio of fluorescence and excitation light could be controlled by adjusting the doping concentration. We confirmed that an angled excitation light incidence suppressed the leakage of excitation light.

레이저 거리 측정기용 광 검출기 수신 감도 실시간 측정 시스템 구현

We propose the method for measuring sensitivity of optical receiver of a long-range laser range finder in real-time. The sensitivity of the detector can be calculated using the detected voltage of the reference sensor, the area of the reference sensor and the transmittance ratio of neutral density filters. To evaluate the performance of the proposed method, we implemented a system and performed experiments. As a result, this system can be measured from 2nW to 113㎼. With this system, we measured the sensitivity of 37nW and 7nW with PIN PD and APD sample, respectively. This system has the advantage for the performance test of an optical sensor module in the long-range laser range finder.

Non-ozone germicidal lamps for units of photochemical and photobiological action

The use of ultraviolet radiation is now becoming more and more important as the method of ultraviolet disinfection successfully destroys bacteria, fungi and viruses. The widespread use of UV radiation has become possible due to the expansion of the production of nomenclature of artificial light sources and increasing their efficiency. To this end, we have proposed the design of non-windowing germicidal lamp for UV irradiation of drinking water, air, surface and other liquids. As the basis of manufacturing technology it is proposed a construction of germicidal lamp, based on the following technical approach - invention, namely the transition from double capped fluorescent lamps to compact single-ended lamps. Design features of germicidal lamp, which limits the output of ozone in the environment, the following: the space between the discharge tube and the outer bulb is a gas filter, the spectral transmittance ratio adjusting pipe diameters and the partial pressure of oxygen and nitrogen. This radiation with a wavelength of 254 nm substantially not delayed by a gas filter, but the amount of ozone is reduced by 3-4 times, without exceeding the allowable limits. UV lamp is equipped with the necessary start-up equipment, which makes it possible to use in the domestic environment for the disinfection of drinking water and surfaces.

Study on the electro-optical properties of polyimide-based polymer-dispersed liquid crystal films

The reflectivity control device, initially developed for attitude control, is utilised to control the solar sail orbit by switching the states between absorption and specular reflection. Actually, the major parts of the device are the polymer-dispersed liquid crystal (PDLC) films. Here, PDLC films based on polyimide (PI) as polymer matrix and a low molecular weight LC can be prepared by the thermally induced phase separation (TIPS) method. The influences of cooling rate and the content of LC on the size and uniformity of LC droplets dispersed in a polymer matrix by a TIPS process were investigated. It was found that a fast cooling rate gave smaller droplet sizes and hence a more uniform distribution as compared to the ones produced under a slow cooling rate. If the LC content was increased, the droplet size would be increased. Furthermore, the effect of LC droplet size on the electro-optical properties of the PI-based PDLC films was discussed, such as transmittance, threshold voltage, driving voltage and contrast ratio (CR).

Measurements of liquid film thickness, concentration and temperature of aqueous NaCl solution by NIR absorption spectroscopy

A multi-wavelength near-infrared (NIR) diode laser absorption sensor has been developed and demonstrated for real-time monitoring of the thickness, solute concentration, and temperature of thin films of urea–water solutions. The sensor monitors the transmittance of three near-infrared diode lasers through the thin liquid film. Film thickness, urea mass fraction, and liquid temperature were determined from measured transmittance ratios of suitable combinations of lasers. Available laser wavelengths were selected depending on the variation of the NIR absorption spectrum of the solution with temperature and solute concentration. The spectral database was measured by a Fourier transform infrared spectrometer in the range 5500–8000 cm−1 for urea solutions between 5 and 40 wt% and temperatures between 298 and 338 K. A prototype sensor was constructed, and the sensor concept was first validated with measurements using a calibration cell providing liquid layers of variable thickness (200–1500 µm), urea mass fraction (5–40 wt%) and temperature (298–318 K). Temporal variations of film thickness and urea concentration were captured during the constant-temperature evaporation of a liquid film deposited on an optically polished heated quartz flat.

Investigation of the High Mobility IGZO Thin Films by Using Co-Sputtering Method

High transmittance ratio in visible range, low resistivity, and high mobility of IGZO thin films were prepared at room temperature for 30 min by co-sputtering of Zn2Ga2O5 (Ga2O3 + 2 ZnO, GZO) ceramic and In2O3 ceramic at the same time. The deposition power of pure In2O3 ceramic target was fixed at 100 W and the deposition power of GZO ceramic target was changed from 80 W to 140 W. We chose to investigate the deposition power of GZO ceramic target on the properties of IGZO thin films. From the SEM observations, all of the deposited IGZO thin films showed a very smooth and featureless surface. From the measurements of XRD patterns, only the amorphous structure was observed. We aimed to show that the deposition power of GZO ceramic target had large effect on the Eg values, Hall mobility, carrier concentration, and resistivity of IGZO thin films. Secondary ion mass spectrometry (SIMS) analysis in the thicknesses’ profile of IGZO thin films found that In and Ga elements were uniform distribution and Zn element were non-uniform distribution. The SIMS analysis results also showed the concentrations of Ga and Zn elements increased and the concentrations of In element was almost unchanged with increasing deposition power.

Electro-Optical Properties of Robust Flexible VA LCDs Using Polymerization Induced Phase Separation

We developed flexible VA LCDs with high electro-optical performance and thermal reliability for flexible display applications. It was achieved by applying the precise control of phase separation, forming well defined cylindrical liquid crystal domains surrounded by polymer matrix. The LC domains have uniform size and the LC molecules inside the domains were well aligned through the contact to vertical alignment layers coated on plastic substrates, so that low driving voltage, high transmittance and high contrast ratio were achieved. We fabricated 5-inch flexible VA LCD panel, showing good electro-optical properties and high mechanical stability.

Optical constants of silicon germanium films grown on silicon substrates

Silicon germanium (Si1−xGex) is a material with high mobility and relatively low bandgap making it an attractive candidate for the bottom subcell in a multi-junction solar cell. Optical constants of Si1−xGex films grown on silicon substrates with germanium (Ge) compositions of 77%, 82%, 85% and 88% from wavelength of 400nm to 1450nm at room temperature are reported. Spectroscopic ellipsometry is used to obtain the real part of refractive index for the whole wavelength range and the extinction coefficients for short wavelengths. Optical transmittance ratio of two structures being different only in the thicknesses of the Si1−xGex films is used to extract the extinction coefficients for long wavelengths. We demonstrate that the optical constants of Si1−xGex films grown on silicon substrates with the aid of graded buffer layers are similar to that of their corresponding bulk materials. However, the absorption coefficients of Si1−xGex with 88% Ge determined by us at around 1000nm is three times higher than previously interpolated results. The main reason for this discrepancy may be due to the inaccuracy of interpolation in the wavelength range where the material's bandgap changes very quickly. In addition, it should be noted that the Ge composition of the Si1−xGex films we are able to obtain are determined to be ±1% which is much more accurate than the previous experimentally determined results which have an accuracy of ±5%.

SF6/Ar plasma textured periodic glass surface morphologies with high transmittance and haze ratio of ITO:Zr films for amorphous silicon thin film solar cells

We report various SF6/Ar plasma textured periodic glass surface morphologies with high transmittance, haze ratio, and root mean square (rms) roughness of ITO:Zr films for amorphous silicon thin film solar cells (a-Si TFSCs). SF6/Ar plasma textured glass surface morphologies contain micro- and nano-textured features that help to scatter the light in visible and near infra-red (NIR) wavelength regions. We designed the textured glass surface morphologies with big square craters to smaller pyramids for various glass etching times from 30 to 75 min. Magnetron sputtered ITO:Zr (∼210 nm) films were deposited on textured glass surface morphologies and showed higher transmittance and haze ratio of 88.48% and 77.61%, respectively, in the visible-NIR (400–1100 nm) wavelength region. The sheet resistance and resistivity of ITO:Zr films decreased with the increase of etching time, due to high rms roughness and better step coverage. A passivation AZO (30 nm) layer was added to the ITO:Zr films, due to its better stability against hydrogen plasma exposure. The ITO:Zr/AZO films were employed as a front TCO layer and the current density–voltage (J–V) characteristics of a-Si TFSCs increased by light scattering effect, without any reduction in either the open circuit voltage (VOC) or the fill factor (FF). Relative to flat glass substrate, JSC and the efficiency of a-Si TFSCs were enhanced by 7.51% and 19.39%, respectively, for textured glass surface morphology.

나노 금속 격자형 편광필름 제작에서 증착 두께에 따른 광 특성 연구

본 연구에서는 대면적 나노 금속 격자형 편광 필름 제작에서 증착 두께에 따른 광 특성 연구를 수행하였다. 나노 금속 격자형 편광필름은 PET(Polyethylene phthalate)기판 위에 알루미늄 선 격자 구조로 구성된다. 본 연구에서는 대면적 편광필름 제작을 위한 증착공정을 통한 금속 격자 형성을 목표로 하였으며, 금속 격자형 편광 필름 제작에 있어 최적의 투과율과 소광비를 가지는 금속 박막 형성 조건을 도출하였다. 최적화 공정에 의해 나노 금속 격자형 편광필름은 140 nm 주기, 70 nm 선폭, 70 nm의 금속층 높이를 가지는 금속 격자 구조로 제작 되었다. 분석결과 600 nm 파장에서 80% 이상의 최고 투과율 및 <TEX>$10^6$</TEX> 이상의 소광비를 가지는 나노 금속 격자 편광필름의 높은 광 특성을 확인하였다. In this study, we demonstrate the change of optical characteristic by thickness of metal deposition on nano metal grid polarizer film fabrication. Nano metal grid polarizer film consists of aluminium grid polarizer layer on PET (Polyethylene phthalate) substrate. We aim at metal grid layer formation for the large nano wire grid polarizer fabrication. we draw process conditions of the nano metal grid polarizer film fabrication to improve transmittance and extinction ratio and Nano wire grid polarizer film (NWGP) film is fabricated with 140 nm pitch, 70 nm width, and 70 nm depth of metal grid on optimum design conditions. As a result, we get high optical properties of nano wire grid polarizer which is the maximum transmittance of 80% and the extinction ratio of <TEX>$10^6$</TEX> at 600 nm wavelength respectively.

Investigation on liquid film of urea–water solutions with diode laser absorption spectroscopy

Measurement of multiparameter of liquid films (e.g., film thickness and concentration) is very important to understand the film formation processes in industrial applications. Here, a novel diode laser absorption spectroscopy (DLAS) sensor was developed to simultaneously measure the liquid film thickness and concentration of urea–water solutions by forming the transmittance ratio at two wavenumber positions. The performance of the sensor employed two diode lasers (6613.25 and 7187.50 cm−1) was first validated using a calibration tool providing liquid film of urea–water solutions with known film thickness (100–1000 μm) and mass fractions (5–50 wt%), and then, the sensor was applied to study a free-falling film of urea–water solutions on a vertical transparent quartz plate. Shadowgraph images were simultaneously taken as a means to obtain falling film thickness, and it was observed that measured film thickness was in good agreement with DLAS method and shadowgraph technique, and the deviation between these two techniques was 4.1 % when the falling film was stable.

Polymer Optical Fiber Temperature Sensor With Dual-Wavelength Compensation of Power Fluctuations

The design and development of a plastic optical fiber macrobend temperature sensor is presented. The sensor can operate in a temperature range from −55 to 70 °C and has a linear response versus temperature with a sensitivity of 8.95·10−4 °C−1. The sensor system uses the ratio of transmittance at two wavelengths to implement a self-referencing technique in order to avoid undesirable power fluctuations influence. The transmittance ratio precision is 0.1%. An analysis has been developed to find the two wavelengths which ratio offers the highest linearity and sensitivity response. Experimental results are successfully compared with theoretical approaches.

Uniform 3D hydrothermally deposited zinc oxide nanorods with high haze ratio

We present low cost hydrothermally deposited uniform zinc oxide (ZnO) nanorods with high haze ratios for the a-Si thin film solar cells. The problem of low transmittance and conductivity of hydrothermally deposited ZnO nanorods was overcome by using RF magnetron sputtered aluminum doped zinc oxide (ZnO:Al ~300nm) films as a seed layer. The length and diameters of the ZnO nanorods were controlled by varying growth times from 1 to 4h. The length of the ZnO nanorods was varied from 1 to 1.5µm, while the diameter was kept larger than 300nm to obtain various aspect ratios. The uniform ZnO nanorods showed higher transmittance (~89.07%) and haze ratio in the visible wavelength region. We also observed that the large diameters (>300nm) and average aspect ratio (3–4) of ZnO nanorods favored the light scattering in the longer wavelength region. Therefore, we proposed uniformly deposited ZnO nanorods with high haze ratio for the future low cost and large area amorphous silicon thin film solar cells.

Ultratransparent Polymer/Semitransparent Silver Grid Hybrid Electrodes for Small‐Molecule Organic Solar Cells

A hybrid ultratransparent poly(3,4-ethyl­enedioxythiophene):poly(styrenesulf­onate) (PEDOT:PSS)/metal grid thin-film is demonstrated as a transparent electrode for organic solar cells. The transmittance of the PEDOT:PSS thin-films on glass reaches values as high as 91.5%, a nearly 100% transmittance ratio. The device with the hybrid electrode shows an efficiency of 2.8%, which is comparable to that of an indium tin oxide based reference device.

Usefulness of Evaluation of Nuclear Color by Visible-Microscopic Spectroscopy for Objective Differentiation between Non-Cancer and Cancer Cells Prepared Using Liquid-Based Cytology

Objective: The aims of this study were to investigate the usefulness of color evaluation of the nuclear region using visible-microscopic spectroscopy (Vis-MS) and to clarify whether it can serve as an index to distinguish cancer cells in liquid-based cytology (LBC). Vis-MS is a spectral analysis technique widely used for absorption and fluorometric analyses in the analytical chemistry field. Vis-MS has been applied to histological diagnosis, but only a few studies on its application to cytology have been performed, and no investigations have been performed for LBC, which is expected to become widely used in Japan. Study design: Using culture cell lines of non-cancer cells and cancer cells, transmittance at 530 nm (maximum absorption wavelength of eosin), 580 nm (hematoxylin), and 630 nm (light green), and 530 nm/580 nm and 630 nm/580 nm transmittance ratios were analyzed. Results: Two variances of the transmittance at 580 nm and 630 nm/580 nm transmittance ratio were finally extracted as effective items after applying forward and backward variance selection and investigation of multicollinearity. The odds ratios of 580 nm transmittance and 630 nm/580 nm transmittance ratio were 0.48 and 0.72, respectively. The cancer cell discrimination predictive value determined using the logistic regression equation was 98.0%, being favorable. Conclusion: It was suggested that Vis-MS is useful to evaluate the color of the nuclear region and serves as a cancer cell discrimination index for LBC. We are planning to apply Vis-MS to clinical materials and develop nuclear color evaluation using Vis-MS into an objective index for cases in which cancer cell judgment is difficult.

磁控溅射法制备的五氧化二钒薄膜光电特性

Vanadium oxide(V2O5)films were deposited on sapphire substrates by Radio Frequency(RF)reactive magnetron sputtering at sputtering time of 15 min,25min,30 min and 45 min.The film structures,film thicknesses,surface morphology,electrical and optical properties were studied at different sputtering time and other experimental parameters unchanged.The results indicate that the deposited films are polycrystalline V2O5 films on(001)preferred orientation.With the increase of sputtering time,crystallization behaviors become stronger,the grain sizes are larger,and the surface roughness values are reduced gradually.Moreover,phase-transition temperatures and temperature ranges are increased while the electrical mutation properties are reduced.The transmittances of the films(thickness of 350nm)in a middle-infrared band were detected at high and low temperatures.The results show that the rangeability of transmittances(wavelength of 5μm)is as high as 74%which ranges from 81% at 25 ℃to 7% at 300 ℃.All the transmittance ratios before and after phasetransitions are between 9—13,showing a very prominent optical-switching property.