Search Results (4)

A plastic-type flat panel photobioreactor (PTFPP) prototype was designed for microalgae cultivation as biodiesel feedstock. The growth, biomass, and lipid production of the oleaginous microalga Scenedesmus obliquus were optimized through the enhanced design and cultivation conditions in the PTFPP. The optimization conditions include cultivation of the microalga in a flat panel photobioreactor manufactured from a 10 µm-thick plastic sheet with dimensions of 40 cm in width and 60 cm in height. The width of the designed plastic bags was adjusted by “4 ports” of circular adhesion points which make the volumetric cultural capacity 5 L. Cultivation of the microalga was optimized through the replacement of the sodium nitrate of the BBM medium with urea as a nitrogen source. Cultivation bags were subjected to continuous illumination with 3000 lux white, fluorescent lamps and aerated with 1.5 L air/min (equal to 0.3 VVM). Biomass production from the designed PTFPP reached 3 g/L with around 40% lipid content (on a dry weight basis). Based on a GC-MS analysis of the produced fatty acid methyl ester (biodiesel) from S. obliquus, the percentage of C16 and C18 fatty acids reached more than 90% of the defined fatty acids. Out of this percentage, 66.6% were unsaturated fatty acids. The produced fatty acid profile of the S. obliquus biomass cultivated in the designed PTFPP prototype could be considered a suitable feedstock for biodiesel production. Full article

Visible light positioning (VLP) technology is a classic application of visible light communication (VLC), which inherits the advantages of VLC and applies it to the field of positioning. LED (light-emitting diode) is a type of light source. Because of its high brightness, aesthetically pleasing characteristics, and ease of installation, it is used in a variety of indoor lighting applications. However, most of the current VLP technology is still in the laboratory simulation stage and cannot be used in industry or life on a large scale due to various reasons, such as accuracy and cost. Because of the large size of LED flat panel lamps, there are almost no VLP applications with LED flat panel lamps as the emitting light source. Therefore, this paper proposes a VLP technology combining LED flat panel light and a barcode, with a single flat panel light at the transmitting end and a smartphone with a camera at the receiving end, to achieve fuzzy positioning. The paper further uses the angle sensor to assist in designing the “pseudo-two-light positioning” algorithm and selects 16 test points for experiments, and the average positioning error can reach a minimum of 6.5023 cm, achieving centimeter-level positioning accuracy requirements. Full article

A coplanar capillary plasma electrode discharge is a promising source owing to its superior performance. In this study, a coplanar capillary plasma electrode discharge flat-panel plasma lamp fabricated from porous anodic alumina and glass was designed to investigate its properties. Coplanar capillary plasma electrode discharge flat-panel lamps with porous anodic alumina dielectric layers were fabricated and investigated. Changing of the frequency and voltage of the power supply and altering of the thickness of the dielectric layers and the interval distance of the electrode were carried out to optimize the performance of the lamps by decreasing the spark-ignition voltage and enhancing the luminous efficacy. The luminance can exceed 7200 Cd/m² and the white light flux efficacy is more than 4.92 lm/W. The discharge process of capillary plasma electrode discharge was modeled and simulated using COMSOL Multiphysics. The electron density and temperature were also analyzed. The results show that small plasma jets were produced at the pores of the porous anodic alumina, which helped stabilize the plasma. The voltage in the gas gap changes sharply with the geometry of the porous anodic alumina dielectric layer, leading to a higher electric field. The spark-ignition voltage decreased. Small plasma jets increase the plasma uniformity. The electron density and electron temperature reach approximately 1.94 × 10⁸ m³ and 3.34 eV, respectively. A high electric field intensity produced at the porous anodic alumina validated the promising potential in related fields. Full article

This research aims to design and fabricate a system to measure the capsaicinoid content of red pepper powder in a non-destructive and rapid method using visible and near infrared spectroscopy (VNIR). The developed system scans a well-leveled powder surface continuously to minimize the influence of the placenta distribution, thus acquiring stable and representative reflectance spectra. The system incorporates flat belts driven by a sample input hopper and stepping motor, a powder surface leveler, charge-coupled device (CCD) image sensor-embedded VNIR spectrometer, fiber optic probe, and tungsten halogen lamp, and an automated reference measuring unit with a reference panel to measure the standard spectrum. The operation program includes device interface, standard reflectivity measurement, and a graphical user interface to measure the capsaicinoid content. A partial least square regression (PLSR) model was developed to predict the capsaicinoid content; 44 red pepper powder samples whose measured capsaicinoid content ranged 13.45–159.48 mg/100 g by per high-performance liquid chromatography (HPLC) and 1242 VNIR absorbance spectra acquired by the pungency measurement system were used. The determination coefficient of validation (R_V²) and standard error of prediction (SEP) for the model with the first-order derivative pretreatment method for Korean red pepper powder were 0.8484 and ±13.6388 mg/100 g, respectively. Full article