Research on Heat Dissipation of Multi-Chip LED Filament Package

By studying the substrate material, structure, chip distribution, and array form of the multi-chip light-emitting diode (LED) package, the heat-dissipation capacity of the LED package is improved. Finite element analysis and steady-state thermal analysis are used to simulate and analyze LED packages with different materials and structures. Using the theory of LED illuminance and uniformity, the illuminance of some structures is computed. The results show that the change of substrate material and structure can greatly impact heat dissipation, while changing array forms has little effect on heat dissipation. By improving the spatial distribution of the chip, the temperature superposition problem of the substrate is solved, and the illuminance and uniformity are improved while dissipating heat. The LED filaments of the combined, equidistant, chip-distribution mode have improved heat dissipation. The S-type equal difference has the highest illumination and high illumination uniformity.

The Effect of Various Salinities and Light Intensities on the Growth Performance of Five Locally Isolated Microalgae [Amphidinium carterae, Nephroselmis sp., Tetraselmis sp. (var. red pappas), Asteromonas gracilis and Dunaliella sp.] in Laboratory Batch Cultures

After a 1.5-year screening survey in the lagoons of Western Greece in order to isolate and culture sturdy species of microalgae for aquaculture or other value-added uses, as dictated primarily by satisfactory potential for their mass culture, five species emerged, and their growth was monitored in laboratory conditions. Amphidinium carterae, Nephroselmis sp., Tetraselmis sp. (var. red pappas), Asteromonas gracilis, and Dunaliella sp. were batch cultured using low (20 ppt), sea (40 ppt), and high salinity (50 or 60 or 100 ppt) and in combination with low (2000 lux) and high (8000 lux) intensity illumination. The results exhibited that all these species can be grown adequately in all salinities and with the best growth in terms of maximum cell density, specific growth rate (SGR), and biomass yield (g dry weight/L) at high illumination (8000 lux). The five species examined exhibited different responses in the salinities used, whereby Amphidinium clearly performs best in 20 ppt, far better than 40 ppt, and even more so than 50 ppt. Nephroselmis and Tetraselmis grow almost the same in 20 and 40 ppt and less well in 60 ppt. Asteromonas performs best in 100 ppt, although it can grow quite well in both 40 and 60 ppt. Dunaliella grows equally well in all salinities (20, 40, 60 ppt). Concerning the productivity, assessed as the maximum biomass yield at the end of the culture period, the first rank is occupied by Nephroselmis with ~3.0 g d.w./L, followed by Tetraselmis (2.0 g/L), Dunaliella (1.58 g/L), Amphidinium (1.19 g/L), and Asteromonas (0.7 g/L) with all values recorded at high light (8000 lux).

The Effect of Various Salinities and Light Intensities on the Growth Performance of Five Locally Isolated Microalgae [Amphidinium carterae, Nephroselmis sp., Tetraselmis sp. (var. red pappas), Asteromonas gracilis and Dunaliella sp.] in Laboratory Batch Cultures

After a 1.5 year screening survey in the lagoons of Western Greece in order to isolate and culture sturdy species of microalgae for aquaculture or other value added uses, as dictated primarily by a satisfactory potential for their mass-culture, five species emerged and their growth was monitored in laboratory conditions. Amphidinium carterae, Nephroselmis sp., Tetraselmis sp. (var. red pappas), Asteromonas gracilis and Dunaliella sp. were batch cultured using low (20 ppt), sea (40 ppt) and high salinity (50 or 60 or 100 ppt) and in combination with a low (2000 lux) and high (8000 lux) intensity of illumination. The results exhibited that all these species can be grown adequately in all salinities and with best growth in terms of maximum cell density, specific growth rate (SGR) and biomass yield (g dry weight/L) at high illumination (8000 lux). The five species examined exhibited different responses in the salinities used, Amphidinium clearly does best in 20 ppt far better than 40 ppt and even more than 50 ppt. Nephroselmis and Tetraselmis grow almost the same in 20 and 40 ppt and less well in 60 ppt. Asteromonas does best in 100 ppt although it can grow quite well in both 40 and 60 ppt. Dunaliella grows equally well in all salinities (20-40-60 ppt). Concerning productivity as maximum biomass yield at the end of the culture period, first rank is occupied by Nephroselmis with ~3.0 g d.w./L, followed by Tetraselmis (2.0 g/L), Dunaliella (1.58 g/L), Amphidinium (1.19 g/L) and Asteromonas (0.7 g/L) with all values recorded at high light (8000 lux).

Wide Area Uniform Illumination Scheme Using LED Matrix for Optogenetic Cardiac Pacing

Control of heart rhythm is vital in the case of arrhythmia. Cardiac optogenetics is a promising technique to replace electrical stimulation in a next generation of pacemakers and defibrillators. Therefore, further research towards optimizing light delivery methods is essential. A major requirement is the uniform stimulation of all cells in the area of interest while reducing side effects such as photodamage. Here, a 2 × 2 blue (470 nm, InGaN-based) light-emitting diode (LED) optoelectronic module for uniform ex vivo cardiac muscle illumination is demonstrated. It satisfies two important requirements in optogenetics, which are high illumination homogeneity and high irradiance. CCD camera images show an average 90% homogeneity over the central illumination area of close to 38 mm2 at 1 cm distance from the light source. The module is used to perform physiological experiments on channelrhodopsin 2-expressing Langendorff-perfused mouse hearts. Successful ventricular pacing is obtained for an optical power density threshold below 2 mW/mm2 with light pulses as short as 1 ms. For 10 ms long pulses, the threshold was below 0.2 mW/mm2. The large homogeneous illumination area enabled optogenetic pacing with less than half the optical power of previous attempts with smaller areas of 2 mm2 and thus, presumably, will result in less phototoxicity.

Sodium sulfite as a switching agent for single molecule based super-resolution optical microscopy

Photoinduced off-switching of organic fluorophores is routinely used in super-resolution microscopy to separate and localize single fluorescent molecules, but the method typically relies on the use of complex imaging buffers. The most common buffers use primary thiols to reversibly reduce excited fluorophores to a non-fluorescent dark state, but these thiols have a limited shelf life and additionally require high illumination intensities in order to efficiently switch the emission of fluorophores. Recently a high-index, thiol-containing imaging buffer emerged which used sodium sulfite as an oxygen scavenger, but the switching properties of sulfite was not reported on. Here, we show that sodium sulfite in common buffer solutions reacts with fluorescent dyes, such as Alexa Fluor 647 and Alexa Fluor 488 under low to medium intensity illumination to form a semi-stable dark state. The duration of this dark state can be tuned by adding glycerol to the buffer. This simplifies the realization of different super-resolution microscopy modalities such as direct Stochastic Reconstruction Microscopy (dSTORM) and Super-resolution Optical Fluctuation Microscopy (SOFI). We characterize sulfite as a switching agent and compare it to the two most common switching agents by imaging cytoskeleton structures such as microtubules and the actin cytoskeleton in human osteosarcoma cells.

LAE-GAN-Based Face Image Restoration for Low-Light Age Estimation

Age estimation is applicable in various fields, and among them, research on age estimation using human facial images, which are the easiest to acquire, is being actively conducted. Since the emergence of deep learning, studies on age estimation using various types of convolutional neural networks (CNN) have been conducted, and they have resulted in good performances, as clear images with high illumination were typically used in these studies. However, human facial images are typically captured in low-light environments. Age information can be lost in facial images captured in low-illumination environments, where noise and blur generated by the camera in the captured image reduce the age estimation performance. No study has yet been conducted on age estimation using facial images captured under low light. In order to overcome this problem, this study proposes a new generative adversarial network for low-light age estimation (LAE-GAN), which compensates for the brightness of human facial images captured in low-light environments, and a CNN-based age estimation method in which compensated images are input. When the experiment was conducted using the MORPH, AFAD, and FG-NET databases—which are open databases—the proposed method exhibited more accurate age estimation performance and brightness compensation in low-light images compared to state-of-the-art methods.

Culture Growth of the Cyanobacterium Phormidium sp. in Various Salinity and Light Regimes and Their Influence on Its Phycocyanin and Other Pigments Content

A strain of the filamentous non N-fixing cyanobacterium Phormidium sp. isolated from the Messolonghi (W. Greece) saltworks, was cultured in the laboratory at six different combinations of salinity (20-40-60 ppt) and illumination (low-2000 lux and high-8000 lux). At salinities of 60 and 40 ppt and in high illumination (XL-8000 lux), the growth rate (μmax) presented the highest values (0.491 and 0.401, respectively) compared to the corresponding at 20 ppt (0.203). In general and at all salinities, the higher illumination (XL) gave the highest growth rates and shorter duplication time (tg) in comparison to the lower illumination (L). On the contrary, phycocyanin, phycoerythrin and allophycocyanin production was extremely increased in the lower illumination (L) in all salinities, from ~14 fold at 40 and 60 ppt to 269 fold at 20 ppt of those corresponding to higher illumination (XL). Similar analogies were also recorded for the other two billiproteins. Chlorophyll-a content was also higher in lower illumination at all salinities in contrast to total carotenoids that did not exhibit such a pattern. The high growth rate and high phycocyanin content along with the rapid sedimentation of its cultured biomass can set this marine Phormidium species as a promising candidate for mass culture.

Culture Growth of the Cyanobacterium Phormidium sp. in Various Salinity and Light Regimes and Their Influence on Its Phycocyanin and Other Pigments Content

A strain of the filamentous non N-fixing cyanobacterium Phormidium sp. isolated from the Messolonghi (W. Greece) saltworks, was cultured in the laboratory at 6 different combinations of salinity (20-40-60 ppt) and illumination (low-2000 lux and high-8000 lux). At salinities of 60 and 40 ppt and in high illumination (XL-8000 lux) the growth rate (μmax) presented the highest values (0.491 and 0.401 respectively) compared to the corresponding at 20 ppt (0.203). In general and at all salinities, the higher illumination (XL) gave the highest growth rates and shorter dublication time (tg) in comparison to the lower illumination (L). On the contrary, phycocyanin, phycoerythrin and allophycocyanin production was extremely increased in the lower illumination (L) in all salinities, from ~14fold at 40 and 60 ppt to 269fold at 20 ppt of those corresponding to higher illumination (XL). Similar analogies were also recorded for the other two billiproteins. Chlorophyll-a content was also higher in lower illumination at all salinities in contrast to total carotenoids that did not exhibit such a pattern. The high growth rate and high phycocyanin content along with the rapid sedimentation of its cultured biomass can set this marine Phormidium species as a promising canditate for mass culture.

Effect of Ambient Illumination, Screen Resolution and Zoom Level on Performance of Typing on Computers

Objective: This work aims to investigate effect of the ambient illumination, screen resolution and Zoom levels on visual-related task performance. The job used in this research is typing on computers. Speed of typing paragraph and typing quality were defined as the task performance. Background: In recent years, computers play a remarkable role in nearly everyone’s daily life. We use computers for various purposes and under a wide range of ambient illumination. High illumination level usually results in some problems. Adjusting screen resolution and zoom level are common solutions contra problems for visibility due to unsuitable illuminations. Method: Ambient illuminations were examined 114, 230, 340, 420 and 520 lx. Screen resolution scales were diverse to cover all range of regulate ability pliable by characteristics of the offering used; 768*1024, 720*1280 and 768*1366. Zoom levels was tested 50, 100, 150 and 200%. Results: Based on this study, can be found that, the more effective illumination level on average typing time was 340 followed by 420 lx. Average typing time decrease with increasing screen resolution, the minimum average typing time observed at 720*1280 and 168*1366 screen resolution. Change the zoom level of text show significant effect on typing time, which the average typing time decreases with increasing zoom level. The minimum typing time observed at 100 and 150% zoom level. Experimental results for all S/N ratio, mean, and standard deviation (real) response values show that, illumination level, screen resolution and zoom scale are the significant parameters among all controllable factors that influence the avearge typing time. Based on S/N Ratio the optimum parameters was 114 lx illumination level and 768*1024 screen Resolution and 50% zoom level. Based on standard deviation the optimum parameters was 114 lx illumination level and 768*1366 screen Resolution and 150% zoom level. Based on the means the optimum parameters was is 230lx illumination level and 768*1366 screen Resolution and 100% zoom level. Conclusion: The provision of suitable illumination, screen resolution and zoom levels that feedback to enhancing the performance of typing performance on computers. Application: This study can inform in-computer typing offices and policy makers concerned with human factors and work-study.

Fluid Nanocarrier for Insulin for Noninvasive Treatment of Diabetes Mellitus

Background A real solution for diabetics to end their suffering with injection and the consequences of poor patient compliance based on the understanding how the body releases insulin as well as the nature of insulin is an argent demand. In this study a novel management strategy was developed using fluid nanocarrier as well as a solution of insulin to treat this problem. The developed nanocarrier is a microemulsion (ME) containing insulin. The transdermal flux of insulin was estimated through rat’s skin using a Franz diffusion cell. Moreover, the efficacy of the treatments was assessed orally and transdermally in rats. Results Based on the rheological properties and droplets size results the formulated fluids were microemulsions. Also, a flux of insulin as high as 1.77±0.22 iu.cm-2.h-1 through rat’s epidermis could be achieved. The short term monitoring of blood sugar level after transdermal application exhibited a slight decrease. On the other hand, the frequent application could achieve a satisfied decline. However, the rapid and significant reduction of the blood sugar level after oral application was surprised. The X-raying of the GI after oral application of the preparation showed high illumination in the lower part of the esophagus and upper part of the stomach. Conclusion This study reveals high potential esophageal absorption using fluid dosage forms. It must be taken in consideration as sublingual and intranasal application. The developed nanofluid can control the blood sugar level orally or in combination with transdermal application and help the diabetics to adhere their therapeutic course.