scholarly journals LIPIDS ACCUMULATION OF CHLORELLA VULGARIS UNDER VARIABLE LIGHTING CONDITIONS

Author(s):  
Magdalena ROKICKA ◽  
Marcin ZIELIŃSKI ◽  
Marcin DĘBOWSKI

The cultivation of microalgae is now an intensively developed research area. Some species of microalgae under appropriate conditions accumulate large amounts of lipids in the cells, which may be a suitable feedstock for biodiesel production. The cultures of microalgae for lipids production should be cultivated in specific physicochemical conditions. The most important environmental parameters affecting the algae growth are: nutrients, lighting, reaction, turbulence, salinity and temperature. Periodic changes in lighting is a key parameter that have a significant effect on cells density and lipid accumulation. The mechanism of this action depends on intensity of light and its spectral composition. To produce 3rd and 4th generation biofuels, a better understanding of the relationship between light conditions and yield of lipids accumulation is necessary. The aim of the study was to determine the effects of variable lighting conditions for lipids accumulation of microalgae Chlorella vulgaris and to determine the most effective lighting parameters. The study confirmed the possibility of using the lighting shock conditions to maximize lipids accumulation in algae Chlorella vulgaris cells. In the study, 33.18% of lipids were obtained from biomass culturing with red light-emitting diodes (LEDs), which was 22% more than obtained with white continuous lighting.

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5994
Author(s):  
Beata Brzychczyk ◽  
Tomasz Hebda ◽  
Norbert Pedryc

Microalgae are a practical source of biological compounds for biodiesel production. This study examined the influence of three different light-emitting diode (LED) systems on the biomass production of green algae Chlorella vulgaris BA0002a. The cultivation was carried out in a photobioreactor illuminated from the bottom with a single side light jacket (PBR I), in a photobioreactor illuminated from the bottom with a double side light jacket (PBR II) and in a photobioreactor illuminated only from the top (PBR III). Research has shown that the intensification of algae cell production and growth depends on the light distribution and exposure time of a single cell to radiation. In the experiment, the highest growth of algae cells was obtained in the photobioreactor with double jacket and lower light panel. The lowest cell growth was observed in the photobioreactor illuminated only from above. For cultures raised in the PBR I and PBR II photobioreactors, increased oxygen production was observed, which was directly related to the increased production of biomass, which in turn was dependent on the increased amount of radiant energy.


Author(s):  
Roberta Paradiso ◽  
Simona Proietti

AbstractLight quantity (intensity and photoperiod) and quality (spectral composition) affect plant growth and physiology and interact with other environmental parameters and cultivation factors in determining the plant behaviour. More than providing the energy for photosynthesis, light also dictates specific signals which regulate plant development, shaping and metabolism, in the complex phenomenon of photomorphogenesis, driven by light colours. These are perceived even at very low intensity by five classes of specific photoreceptors, which have been characterized in their biochemical features and physiological roles. Knowledge about plant photomorphogenesis increased dramatically during the last years, also thanks the diffusion of light-emitting diodes (LEDs), which offer several advantages compared to the conventional light sources, such as the possibility to tailor the light spectrum and to regulate the light intensity, depending on the specific requirements of the different crops and development stages. This knowledge could be profitably applied in greenhouse horticulture to improve production schedules and crop yield and quality. This article presents a brief overview on the effects of light spectrum of artificial lighting on plant growth and photomorphogenesis in vegetable and ornamental crops, and on the state of the art of the research on LEDs in greenhouse horticulture. Particularly, we analysed these effects by approaching, when possible, each single-light waveband, as most of the review works available in the literature considers the influence of combined spectra.


2021 ◽  
Vol 21 (3) ◽  
pp. 1996-2000
Author(s):  
Byeong-Guk Kang ◽  
Seung-Gu Kang

In this study, glass-ceramic was prepared by adding TiO2 as a nucleating agent to induce the internal crystallization behavior of diopside (CaO-MgO-2SiO2)-based glass. The optimum composition for producing a transparent glass-ceramic was a composition of 15 wt% of TiO2 mixed with 85% diopside. The light transmittance of the specimen decreased as the heat treatment temperature increased. When 394 nm excitation light was incident on the glass-ceramic containing 0.05% Eu2O3, red light of 614 nm wavelength emitted. We examined the relationship between the light emission mechanism and the crystal structure of the diopside-based glass-ceramic. We also discussed the applicability of the specimens prepared in this study as light emitting materials in various fields.


2020 ◽  
Vol 13 (2) ◽  
pp. 112-121
Author(s):  
Sudiyar . ◽  
Okto Supratman ◽  
Indra Ambalika Syari

The destructive fishing feared will give a negative impact on the survival of this organism. This study aims to analyze the density of bivalves, distribution patterns, and to analyze the relationship of bivalves with environmental parameters in Tanjung Pura village. This research was conducted in March 2019. The systematic random system method was used for collecting data of bivalves. The collecting Data retrieval divided into five research stasions. The results obtained 6 types of bivalves from 3 families and the total is 115 individuals. The highest bivalve density is 4.56 ind / m², and the lowest bivalves are located at station 2,1.56 ind / m²,  The pattern of bivalve distribution in the Coastal of Tanjung Pura Village is grouping. The results of principal component analysis (PCA) showed that Anadara granosa species was positively correlated with TSS r = 0.890, Dosinia contusa, Anomalocardia squamosa, Mererix meretrix, Placamen isabellina, and Tellinella spengleri were positively correlated with currents r = 0.933.


2020 ◽  
Vol 19 (11) ◽  
pp. 1224-1229 ◽  
Author(s):  
Alim Abdurahman ◽  
Timothy J. H. Hele ◽  
Qinying Gu ◽  
Jiangbin Zhang ◽  
Qiming Peng ◽  
...  

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Lung-Chien Chen ◽  
Yi-Tsung Chang ◽  
Ching-Ho Tien ◽  
Yu-Chun Yeh ◽  
Zong-Liang Tseng ◽  
...  

AbstractThis work presents a method for obtaining a color-converted red light source through a combination of a blue GaN light-emitting diode and a red fluorescent color conversion film of a perovskite CsPbI3/TOPO composite. High-quality CsPbI3 quantum dots (QDs) were prepared using the hot-injection method. The colloidal QD solutions were mixed with different ratios of trioctylphosphine oxide (TOPO) to form nanowires. The color conversion films prepared by the mixed ultraviolet resin and colloidal solutions were coated on blue LEDs. The optical and electrical properties of the devices were measured and analyzed at an injection current of 50 mA; it was observed that the strongest red light intensity was 93.1 cd/m2 and the external quantum efficiency was 5.7% at a wavelength of approximately 708 nm when CsPbI3/TOPO was 1:0.35.


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