scholarly journals Study of Algal Species Isolated From River Ginzo in Katsina State, as a Potential Source for Biodiesel Production

2021 ◽  
Vol 25 (5) ◽  
pp. 793-798
Author(s):  
L. Umar ◽  
A. Bashir ◽  
I. Haruna ◽  
G.A. Hadiza ◽  
A.J. Shamsudeen
Keyword(s):  
Growth Rate ◽  
Algal Species ◽  
High Growth ◽  
Biomass Productivity ◽  
High Growth Rate ◽  
Biodiesel Production ◽  
Cell Counts ◽  
Candidate Species ◽  
Chlorella Species ◽  
Ph Range

An ecological study of algae at River Ginzo in Katsina town was carried out for six weeks at three different sites. In this study, various strains of native microalgae were identified and isolated. The water's physicochemical properties were analyzed at Kofar Marusa, Kofar Sauri, and Kofar Durbi of River Ginzo in Katsina State. The physicochemical parameters studied showed temperature and pH range of 28oC to 31oC and 6.42 to 7.36. A total of eighteen (18) algal species were identified, out of which Ten (10) species belong to the Class Chlorophyceae with Spirogyra species having the highest cell counts, five (5) species belong to the Class Cyanophyceae with Oscillatoria species having the highest cell count and three (3) species belong to the Class Bacillariophyceae with Nitzchia spp having the highest cell counts. Among the isolates, Chlorella species showed an increased growth rate with higher biomass productivity of (88.67±2.57) X 104 (cell/ml) after six days of incubation. The results showed that Chlorella, Spirogyra, and Oocystis species could be a possible candidate species for producing oils for sustainable biodiesel production, based on their high growth rate and presence in all the locations.

scholarly journals The isolation and screening of microalgae for the production of oil

2017 ◽  
Vol 71 (1) ◽  
pp. 69-74
Author(s):  
Bojana Danilovic ◽  
Jelena Cvetkovic-Rakic ◽  
Jovan Ciric ◽  
Jelica Simeunovic ◽  
Vlada Veljkovic ◽  
...  
Keyword(s):  
Growth Rate ◽  
Oil Content ◽  
High Growth ◽  
Good Alternative ◽  
High Growth Rate ◽  
Biodiesel Production ◽  
Freshwater Microalgae ◽  
Chlorella Sp ◽  
Fatty Acids Profile ◽  
Oil Productivity

The biodiesel production has gained increasing attention of the researches in recent years. Current commercial biodiesel production involves transesterification of oil derived from oil crops. Since this production is no more sustainable, the use of microalgae represents a good alternative. Microalgae have high growth rate, high oil content and can be cultured in the environment which are not suitable for agriculture. Additionally, microalgae cultivation improves the reduction of carbon dioxide in the atmosphere. Selection of microalgae for oil production must take into consider certain criteria which include growth rate, oil content, fatty acids profile and ease of separation. In order to analyze the possibility of the use of microalgae for the production of oil, isolation of freshwater microalgae was performed. The isolation was done by the use of traditional techniques from freshwaters near Leskovac. A total number of 6 microalgae strains were isolated and identified as the representatives of the genera Chlorococcum (1 isolate), Chlorella (1 isolate), Scenedesmus (1 isolate) and Desmodesmus (3 isolates). Isolates of microalgae were screened for the growth rate, biomass and oil productivity and oil content. The highest content of biomass was 1.5 g/l and it was observed in the strains Chlorococcum sp. and Desmodesmus sp. 1. The highest value of specific growth rate was calculated during the growth of microalgae Chlorella sp., Scenedesmus sp. and Desmodesmus sp.1, while the lowest value was observed for Chlorococcum sp. Oil productivity was the highest for Chlorella sp. and Desmodesmus sp.1 (0,4 g/l) and the lowest for Desmodesmus sp.2, Desmodesmus sp.3 and Chlorococcum sp. (0,2 g/l). The oil content was in the range from 15.8% (Chlorococcum sp.) to 33% (Chlorella sp). Since the microalgae isolates Chlorella sp. and Scenedesmus sp. had the highest oil productivity, high growth rate and high oil content, these strains are the most suitable for further investigation in order to improve the oil yield and analyse the possibility of the use in the production of biodiesel.

scholarly journals Growth, biomass and lipid productivity of a newly isolated tropical marine diatom, Skeletonema sp. UHO29, under different light intensities

2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Indrayani Indrayani ◽  
Haslianti Haslianti ◽  
Asmariani Asmariani ◽  
Wellem Muskita ◽  
Abdul Muis Balubi
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
High Growth ◽  
Biomass Productivity ◽  
Dry Weight ◽  
High Light Intensity ◽  
High Growth Rate ◽  
Lipid Productivity ◽  
Marine Diatom ◽  
Light Intensities

Abstract. Indrayani I, Haslianti H, Asmariani A, Muskita WH, Balubi M. 2020. Growth, biomass and lipid productivity of a newly isolated tropical marine diatom, Skeletonema sp. UHO29, under different light intensities. Biodiversitas 21: 1498-1503. Light is one of the important factors affecting growth and biochemical composition of microalgae. The aim of this study was to determine growth, biomass and lipid productivity of a newly isolated marine diatom, Skeletonema sp.UHO29 under different light intensities. The Skeletonema sp. was cultured in 300 mL conical flasks containing 150 mL of f/2 medium under three different light intensities (28, 60 and 110 μmol photons m-2 s-1 ) with three replications. The cultures were incubated under ambient room temperatures, and a cycle of 12 hours light and 12 hours dark, in batch modes for two weeks. The results showed that the highest specific growth rate (0.56 d-1) was achieved at the highest light intensity (110 μmol photons m-2 s-1) and the lowest (0.11 d-1) was obtained at the lowest light intensity (28 μmol photons m-2 s-1). The highest biomass yield (0.62 g L-1) and biomass productivity (0.34 g L-1 d-1) was achieved at the highest light intensity. However, the highest lipid yield (0.175 g L-1), lipid content (28.78% ash-free dry weight) and lipid productivity (0.067 g L-1 d-1) were achieved at medium light intensity. The alga prefers high light intensity for higher growth rate and biomass productivity but it produces more lipids at medium light intensity. This study indicated that the Skeletonema sp.UHO29 is a potential species for outdoor mass cultivation and is a promising microalgal strain for use as a biodiesel feedstock due to its high growth rate, high biomass and lipid productivity.

Exploring SiC Growth Limitation of Vapor-Liquid-Solid Mechanism when Using Two Different Carbon Precursors

2013 ◽  
Vol 740-742 ◽  
pp. 323-326
Author(s):  
Kassem Alassaad ◽  
François Cauwet ◽  
Davy Carole ◽  
Véronique Soulière ◽  
Gabriel Ferro
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
High Growth Rate ◽  
Carbon Precursor ◽  
Growth Limitation ◽  
Vapor Liquid Solid ◽  
Partial Pressures ◽  
Vapor Liquid Solid Mechanism ◽  
Vls Growth ◽  
Vapor Liquid

Abstract. In this paper, conditions for obtaining high growth rate during epitaxial growth of SiC by vapor-liquid-solid mechanism are investigated. The alloys studied were Ge-Si, Al-Si and Al-Ge-Si with various compositions. Temperature was varied between 1100 and 1300°C and the carbon precursor was either propane or methane. The variation of layers thickness was studied at low and high precursor partial pressure. It was found that growth rates obtained with both methane and propane are rather similar at low precursor partial pressures. However, when using Ge based melts, the use of high propane flux leads to the formation of a SiC crust on top of the liquid, which limits the growth by VLS. But when methane is used, even at extremely high flux (up to 100 sccm), no crust could be detected on top of the liquid while the deposit thickness was still rather small (between 1.12 μm and 1.30 μm). When using Al-Si alloys, no crust was also observed under 100 sccm methane but the thickness was as high as 11.5 µm after 30 min growth. It is proposed that the upper limitation of VLS growth rate depends mainly on C solubility of the liquid phase.

Very High Growth Rate of 4H-SiC Using MTS as Chloride-Based Precursor

2008 ◽  
Vol 600-603 ◽  
pp. 115-118 ◽  
Author(s):  
Henrik Pedersen ◽  
Stefano Leone ◽  
Anne Henry ◽  
Franziska Christine Beyer ◽  
Vanya Darakchieva ◽  
...  
Keyword(s):  
Growth Rate ◽  
Linear Dependence ◽  
Growth Rates ◽  
Molar Fraction ◽  
High Growth ◽  
High Growth Rate ◽  
Epitaxial Layers ◽  
Single Precursor ◽  
Very High

The chlorinated precursor methyltrichlorosilane (MTS), CH3SiCl3, has been used to grow epitaxial layers of 4H-SiC in a hot wall CVD reactor, with growth rates as high as 170 µm/h at 1600°C. Since MTS contains both silicon and carbon, with the C/Si ratio 1, MTS was used both as single precursor and mixed with silane or ethylene to study the effect of the C/Si and Cl/Si ratios on growth rate and doping of the epitaxial layers. When using only MTS as precursor, the growth rate showed a linear dependence on the MTS molar fraction in the reactor up to about 100 µm/h. The growth rate dropped for C/Si < 1 but was constant for C/Si > 1. Further, the growth rate decreased with lower Cl/Si ratio.

Emission characteristics of GaInN/GaN multiple quantum shell nanowire-based LEDs with different p-GaN growth conditions

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sae Katsuro ◽  
Weifang Lu ◽  
Kazuma Ito ◽  
Nanami Nakayama ◽  
Naoki Sone ◽  
...  
Keyword(s):  
Growth Rate ◽  
Shell Growth ◽  
Light Output ◽  
High Growth ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Current Injection ◽  
Emission Characteristics ◽  
Multiple Quantum ◽  
Plane Region

Abstract Improving current injection into r- and m-planes of nanowires (NWs) is essential to realizing efficient GaInN/GaN multiple quantum shell (MQS) NW-based light-emitting diodes (LEDs). Here, we present the effects of different p-GaN shell growth conditions on the emission characteristics of MQS NW-LEDs. Firstly, a comparison between cathodoluminescence (CL) and electroluminescence (EL) spectra indicates that the emission in NW-LEDs originates from the top region of the NWs. By growing thick p-GaN shells, the variable emission peak at around 600 nm and degradation of the light output of the NW-LEDs are elaborated, which is attributable to the localization of current in the c-plane region with various In-rich clusters and deep-level defects. Utilizing a high growth rate of p-GaN shell, an increased r-plane and a reduced c-plane region promote the deposition of indium tin oxide layer over the entire NW. Therefore, the current is effectively injected into both the r- and m-planes of the NW structures. Consequently, the light output and EL peak intensity of the NW-LEDs are enhanced by factors of 4.3 and 13.8, respectively, under an injection current of 100 mA. Furthermore, scanning transmission electron microscope images demonstrate the suppression of dislocations, triangular defects, and stacking faults at the apex of the p-GaN shell with a high growth rate. Therefore, localization of current injection in nonradiative recombination centers near the c-plane was also inhibited. Our results emphasize the possibility of realizing high efficacy in NW-LEDs via optimal p-GaN shell growth conditions, which is quite promising for application in the long-wavelength region.

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