Development of a Semi-Empirical Model for Droplet Size Determination of a Three-Channel Spray Nozzle for Pellet Coating Based on the Optical Method Concept

The purpose of this study was to investigate the droplet size obtained with a three-channel spray nozzle typically used in fluid bed devices and to construct a semi-empirical model for prediction of droplet size. With the aid of a custom-made optical method concept, the impact of the type of polymer and solvents used through dispersion properties (viscosity, density, and surface tension), dispersion flow rate, atomization pressure, and microclimate pressure on droplet size was investigated. A semi-empirical model with adequate predictability for calculating the average droplet size (R2 = 0.90, Q2 = 0.73) and its distribution (R2 = 0.84, Q2 = 0.61) was constructed by employing dimensional analysis and design of experiments. Newtonian and non-Newtonian dispersion and process parameters on laboratory and on production scale were included, thereby enabling constant droplet size irrespective of the scale. Based on the model results, it would be possible to scale-up the atomization process (e.g., coating process) from laboratory to production scale in a systematic fashion, regardless of the type of solvent or polymer used. For the system investigated, this can be performed by understanding the dispersion properties, such as viscosity, density, and surface tension, as well as the following process parameters: dispersion flow rate, atomization, and microclimate pressure.

New Optical Method for the Sucrose Solution Measurement Based on Fano Resonance

We propose a new method to determine the concentration of a sucrose solution based on Fano resonance, demonstrate that the [Formula: see text]-shaped resonator and rectangular resonator structures can realize the Fano resonance, observe higher sensitivity up to 2142 nm/RIU, and use the structure to measure the concentration of a sucrose solution. This work shows that the Fano resonance wavelength removed to longer wavelengths as the concentration of the solution increased, and the resolution of solution concentration is [Formula: see text], which can be used for measuring the concentration of solutions other than sucrose. This research is an important first step towards creating the industrial application of photon properties to extend photon polariton applications throughout the infrared.

Investigation of Enhanced Ambient Contrast Ratio in Novel Micro/Mini-LED Displays

In recent years, ambient contrast ratio (ACR) has become very critical for advanced outdoor displays, including transparent displays, portable displays, and so on. In this work, the ACR of typical flat panel displays was introduced, while LED-based displays showed distinctive advantages. Micro-LED displays with a different pitch of 10 μm, 15 μm, 30 μm, and 60 μm were fabricated and characterized. Various mini-LED and micro-LED panels were systematically investigated in the aspect of brightness, reflection phenomenon, and ACR to reveal their enormous potential for outdoor applications. Through a series of experiments and comparisons, three methods were proposed to further improve the ACR of LED-based panels, including optical method, antireflection coating, and structure optimization.

GAS TEMPERATURE MEASUREMENT IN THE ACTIVE ZONE OF STREAMER DISCHARGE UNDER DIFFERENT APPLIED VOLTAGES

The experimental results on the gas temperature measurement in the active zone of streamer discharge in air at the atmospheric pressure are presented. The gas temperature value was obtained by the optical method for measur-ing the relative intensity of the rotational lines for the radiation of the second positive (II+) system of molecular ni-trogen, transition bands (С3Пu(0)→B3Пg(0)). It was found that in discharge gap d = 8 mm, depending on the ap-plied voltage (in the range of 6.1…7.8 kV with a step of 0.2 kV), the gas temperature varied from 609 to739 K. The unevenness of the gas temperature change in the active zone of discharge with the increase in the applied voltage is shown. This may be related to the possible changes in the rotational state of nitrogen molecules upon excitation of their electronic state by electrons.

Establishment of a simple method to evaluate mixing times in a plastic bag photobioreactor using image processing based on freeware tools

Objective Accurate determination of the mixing time in bioreactors is essential for the optimization of the productivity of bioprocesses. The aim of this work was to develop a simple optical method to determine the mixing time in a photobioreactor. The image processing method should be based on freeware tools, should not require programming skills, and thus could be used in education within high schools and in early stages of undergraduate programs. Results An optical method has been established to analyze images from recorded videos of mixing experiments. The steps are: 1. Extraction of a sequence of images from the video file; 2. Cropping of the pictures; 3. Background removal; and 4. Image analysis and mixing time evaluation based on quantification of pixel-to-pixel heterogeneity within a given area of interest. The novel method was generally able to track the dependency between aeration rate and mixing time within the investigated photobioreactor. In direct comparison, a pearson correlation coefficient of rho = 0.99 was obtained. Gas flow rates between 10 L h−1, and 300 L h−1 resulted from mixing times of between 48 and 14 s, respectively. This technique is applicable without programming skills and can be used in education with inexperienced user groups.

On the possibility of using the optical method for express quality control of fruits

The necessity of express control of fruit quality in various situations has been substantiated. Various methods for the implementation of express control of fruit quality in express mode are considered. A method for express control of fruit quality using laser radiation has been developed. The change in the degree of spatial coherence in the recorded reflected laser radiation from defects on the surfaces of fruits was investigated. Experimental results of the study of various defects on fruits, as well as their hardness and degree of ripening, are presented using the method developed by us.

The optical and electrical non-invasive methods of measurement for glucose concentration in biological liquids

The article describes the radio-wave and optical methods of determining glucose concentration. The radio-wave method is based on the use of a sensor with a resonant frequency that is displayed when in contact with highly lossy materials and with an extended near-field zone in the resonance area. The optical method is based on studying the influence of glucose concentration (0–20 mmol/l) in bidistilled water on absorption spectra in the range of 190-1000 nm. The article presents the results of the experimental test of the near-field sensor with the pre-produced biological media imitating the human body tissues, and the results of the optical method demonstrate the possibility to measure the concentration with the use of an optical emitter with a wave length of 830 nm.