scholarly journals Effect of Nutrient, Light Intensity and Temperature on the Growth Rates and Metabolism of a Stress-Resistant Bacillariophyta – Entomoneis sp. - in Izmir Bay (Aegean Sea)

2020 ◽  
Vol 21 (1) ◽  
pp. 1
Author(s):  
SEZGI ADALIOĞLU ◽  
GÜLIZAR ÇALIŞKAN

A unicellular marine microalga, Entomoneis sp. was isolated and studied as had become the dominant species according to other bacillariophyta species in different environmental fluctuations in Izmir Bay. Because of our effort to better understand the dynamics of this microalga that facilitates unprecedented domination, we conducted on a monoculture isolation study.In this study, experiments were planned with the annual range of the Izmir Bay temperature, and the demonstrated behavior of the species in light and nutrient conditions. The stock culture medium was illuminated by approximately 50μmol photons m-2s-1 of illumination with 14/24 daylight. The temperature of the climate chamber was set on the summer (T1 (21±1oC)), spring (T2 (17±1oC)) and winter (T3 (13±1oC)) of Izmir Bay. Experiments were also applied with four different light intensities (L1 (50 μmol photons m-2s-1), L2 (25 μmol photons m-2s-1), L3 (5 μmol photons m-2s-1) and L4 (dark)). In this context, nutrient measurements were made on samples of the exponential, stationary and death phase of the culture and nutrient analyses were carried out. The results, which were designed according to ceteris paribus assumptions, were adapted to Michaelis-Menten kinetics. Consequently, considering the lifetime of the diatom at different temperature conditions, T3 was determined as an optimum temperature. Maximum growth rate and process time were observed at this temperature. This is the evidence why these diatoms are available in the winter. Once the light intensity was increased, the growth rate was increased at the T1 and T2 temperatures. However, T3 had a high growth rate in the nearly L1 light intensity. Considering the consumption and transformation of different nutrient conditions, different results for both types of microalgae were obtained. 

2008 ◽  
Vol 600-603 ◽  
pp. 111-114 ◽  
Author(s):  
Masahiko Ito ◽  
L. Storasta ◽  
Hidekazu Tsuchida

A vertical hot-wall type epi-reactor that makes it possible to simultaneously achieve both a high rate of epitaxial growth and large-area uniformity at the same time has been developed. A maximum growth rate of 250 µm/h is achieved at 1650 °C. Thickness uniformity of 1.1 % and doping uniformity of 6.7 % for a 65 mm radius area are achieved while maintaining a high growth rate of 79 µm/h. We also succeeded in growing a 280 µm-thick epilayer with excellent surface morphology and long carrier lifetime of ~1 µs on average. The LTPL spectrum shows free exciton peaks as dominant, and few impurity-related or intrinsic defect related peaks are observed. The DLTS measurement for an epilayer grown at 80 µm/h shows low trap concentrations of 1.2×1012 cm-3 for Z1/2 center and 6.3×1011 cm-3 for EH6/7 center, respectively.


2016 ◽  
Vol 858 ◽  
pp. 23-28 ◽  
Author(s):  
Jun Kojima ◽  
Yuichiro Tokuda ◽  
Emi Makino ◽  
Naohiro Sugiyama ◽  
Norihiro Hoshino ◽  
...  

In order to diffuse the use of SiC, mass-production technologies of SiC wafers are needed. It is easy to be understood that high-speed and long-sized growth technologies are connected directly with mass-production technologies. The gas source growth method such as HT-CVD has the possibilities and the potential of the high-speed and long-sized growth. In this article, it was clarified that the high growth rate were achieved by the control of the source gas partial pressures and by the gas boundary layers. The average growth rate was 1mm/h on the f4 inch-diameter crystal, and the maximum growth rate reached 3.6 mm/h on the 12.5x25 mm tetragon by the above gas control. The crystal qualities of the gas source methods were also evaluated the equivalent level in comparison with the sublimation method. Concerning the 1mm/h-growth f3 inch crystal, the densities of TSDs were kept in the 102 cm-2 levels from the seed to the upper-side of the ingot. Moreover, the ingot size increased year by year and a f4 inch x 43 mm sized ingot has been developed.


1975 ◽  
Vol 32 (3) ◽  
pp. 427-448 ◽  
Author(s):  
M. C. Healey

Available data on mortality, growth, reproduction, and stock size in exploited and unexploited populations of lake whitefish (Coregonus clupeaformis) are reviewed with a view to understanding the dynamics of exploited populations and improving their management. Natural mortality ranged from about 0.20 to 0.80 in unexploited populations. In exploited populations total mortality was as high as 0.94. Unexploited populations showed a wide range of growth rates. Growth rate increased with increasing exploitation, and growth rate in all heavily exploited populations was similar to the most rapid growth rate shown by unexploited stocks. Heavily exploited whitefish matured at a younger age and possibly also at a smaller size than those which were unexploited. Limited data on stock size suggest that although total population size declines under heavy exploitation, the vulnerable population remains of similar size.It is concluded that whitefish respond to fluctuations in population size through compensatory changes in growth rate, the difference between growth rate in a population and maximum growth rate is a measure of its scope for compensating for increased mortality. Populations with slow growth rate and low mortality should, therefore, have the best fishery potential, while those with high growth rate and high mortality have a low fishery potential. Further, it is possible to judge the fishery potential of a population or its stage of exploitation from relatively simple measurements of mortality, growth, age structure, and maturity.


2021 ◽  
Vol 273 ◽  
pp. 02024
Author(s):  
Anatoly Shevkhuzhev ◽  
Vladimir Pogodaev ◽  
Dagir Smakuev

The aim of the research was to establish quantitative and qualitative indicators of meat productivity of Simmental bull calves of various constitutional types when raised using the technology of beef cattle breeding. The maximum growth rate and the highest yield of meat products were obtained from Simmental bulls of the meat and dairy type when they were raised and fed according to the technology of beef cattle breeding. Receiving from the mothers for 205 days of the sucking period more fatty milk, they gave 1250 g of gain per day and reached 289.7 kg of live weight by the cut. Having retained a high growth rate in the future, they at the final fattening gave 1321 g of gain per day and at 20 months the live weight was 659.3 kg. The superiority of Simmentals over analogues was natural by 3.4–13.3% by weight of the steamed carcass, by 0.4–1.8% in slaughter yield, by 1.4–11.1 kg in terms of the amount of pulp in the carcass and pulp per bones by 0.1–0.3 kg, protein in meat by 0.12; 1.19; 2.59 kg and the amount of energy in the pulp by 0.14; 0.44; 1.75 MJ. Simmental bulls of the meat and dairy type also have a high ability to transform protein and feed energy into protein and energy from the pulp of the carcass.


Author(s):  
Indrayani Indrayani ◽  
Haslianti Haslianti ◽  
Asmariani Asmariani ◽  
Wellem Muskita ◽  
Abdul Muis Balubi

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.


1961 ◽  
Vol 38 (3) ◽  
pp. 595-604
Author(s):  
D. R. SWIFT

1. A regular annual growth-rate cycle is demonstrated in wild and hatchery yearling brown trout; the fish have a high growth rate in the spring and autumn and a low growth rate during the summer and winter of each year. 2. Experimental work with constant-environment aquaria, together with the results of the field work, indicate that the water temperature is the main external environmental factor influencing the growth rate. Maximum growth rate is achieved at 12° C. 3. The reason for the fall in growth rate above 12° C. is discussed and it is suggested that inadequacy of the respiratory system of the fish is the prime cause.


2007 ◽  
Vol 556-557 ◽  
pp. 81-84
Author(s):  
Masahiko Ito ◽  
Hidekazu Tsuchida ◽  
Isaho Kamata ◽  
L. Storasta

A vertical hot-wall type reactor, with a unique structure designed for controlling both gas flow behavior and thermal gradient (T/mm) on the susceptor surface, was developed. The simulation results indicate that depending on the height of the epitaxy room (h), the T/mm can be changed from a negative to a positive value. Preliminary epitaxial growth experiments resulted in a maximum growth rate of 51 μm/h, 4-inch area uniformity of σ/mean=1.7% for growth rate and σ/mean=21.5 % for doping concentration, and Z1/2 trap concentration of 9×1012 cm-3 at a growth rate of 43 μm/h.


2013 ◽  
Vol 740-742 ◽  
pp. 323-326
Author(s):  
Kassem Alassaad ◽  
François Cauwet ◽  
Davy Carole ◽  
Véronique Soulière ◽  
Gabriel Ferro

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.


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