Evaluation of quantitative glare technique based on the analysis of bio-signals.

This laboratory study evaluated the effect of glare source (halogen, HID and LED) and its illumination levels (0.7, 2 and 5 lx) using a quantitative methodology. Pupil diameter and electroencephalography were measured using FaceLab and Biopac systems, respectively. The discomfort glare was assessed subjectively with Borg's CR-10 scale. Twenty healthy subjects participated. Pupil size was significantly affected by the headlamp type and illumination condition. Pupil size was smaller when exposed to the LED headlamp than other headlamps (Halogen > HID > LED). In addition, when the illumination increased, pupil size decreased (0.7 lx > 2 lx > 5 lx). Also, driver's discomfort increased when pupil size was small, and theta waves were high. This discomfort may cause reduced attention and safety of the driver. These results can be applied to design and development of headlamps. Further investigation is necessary with adopted methodology to evaluate other headlamps in different illumination conditions. Practitioner Summary: This study evaluated pupil size and electroencephalography under different glare source (halogen, HID and LED) and illumination levels (0.7, 2 and 5 lx). Driver's discomfort increased when pupil size was small, and theta waves were high. This discomfort may cause reduced attention and safety of the driver.

Specific light uptake rates can enhance astaxanthin productivity in Haematococcus lacustris.

Lumostatic operation was applied for efficient astaxanthin production in autotrophic Haematococcus lacustris cultures using 0.4-L bubble column photobioreactors. The lumostatic operation in this study was performed with three different specific light uptake rates (q(e)) based on cell concentration, cell projection area, and fresh weight as one-, two- and three-dimensional characteristics values, respectively. The q(e) value from the cell concentration (q(e1D)) obtained was 13.5 × 10⁻8 µE cell⁻¹ s⁻¹, and the maximum astaxanthin concentration was increased to 150 % compared to that of a control with constant light intensity. The other optimum q e values by cell projection area (q(e2D)) and fresh weight (q( e3D)) were determined to be 195 µE m⁻² s⁻¹ and 10.5 µE g⁻¹ s⁻¹ for astaxanthin production, respectively. The maximum astaxanthin production from the lumostatic cultures using the parameters controlled by cell projection area (2D) and fresh weight (3D) also increased by 36 and 22% over that of the controls, respectively. When comparing the optimal q e values among the three different types, the lumostatic cultures using q(e) based on fresh weight showed the highest astaxanthin productivity (22.8 mg L⁻¹ day⁻¹), which was a higher level than previously reported. The lumostatic operations reported here demonstrated that more efficient and effective astaxanthin production was obtained by H. lacustris than providing a constant light intensity, regardless of which parameter is used to calculate the specific light uptake rate.

Viewing angle enhanced integral imaging display by using a high refractive index medium.

In the integral imaging system, the viewing angle is limited by the size and focal length of the elemental lens. In this regard, we propose a new method for the viewing angle enhancement in the InIm. The proposed method employs a refractive index medium between the elemental image plane and the lens array. The viewing angle enhanced InIm display is analyzed based on the imaging terms. The experimental result shows that the viewing angle is doubled.

Effect of Electrode Materials on the Electrical Characteristics of Amorphous Indium-Tin-Gallium-Zinc Oxide Thin-Film Transistors.

In this study, we investigated the effect of electrode materials on the electrical characteristics of coplanar top-gate a-ITGZO thin-film transistors, in which the gate, source, and drain electrodes were made of the same metal, Ti or Al. The field-effect mobilities of the a-ITGZO thin-film transistors with Ti and Al electrodes were 35.2 and 20.1 cm²/V·s, respectively, and the threshold voltage of the a-ITGZO thin-film transistor with Ti electrodes was -0.4 V, whereas that of the transistor with Al electrodes was -1.8; this shift is attributed to the fact that Ti has a higher work function than Al. When Ti was used as the source and drain electrode material, the channel resistance and effective channel length were reduced owing to the penetration of metal atoms into the channel region from the edge of the source/drain electrodes.

Enhancing Photon Utilization Efficiency for Astaxanthin Production from Haematococcus lacustris Using a Split-Column Photobioreactor.

A split-column photobioreactor (SC-PBR), consisting of two bubble columns with different sizes, was developed to enhance the photon utilization efficiency in an astaxanthin production process from Haematococcus lacustris. Among the two columns, only the smaller column of SC-PBR was illuminated. Astaxanthin productivities and photon efficiencies of the SC-PBRs were compared with a standard bubble-column PBR (BC-PBR). Astaxanthin productivity of SC-PBR was improved by 28%, and the photon utilization efficiencies were 28-366% higher than the original BC-PBR. The results clearly show that the effective light regime of SC-PBR could enhance the production of astaxanthin.