scholarly journals Experiment and Kinetic Modeling of Soil Extract Effects on Dunaliella Primolecta Growth

2021 ◽  
Author(s):  
Dzulkarnain Ahmad ◽  
Intan Faraha A Ghani ◽  
Nor Suhaila Yaacob ◽  
Mokhtazul Haizad Mokhtaram ◽  
Mohd Fadzli Ahmad ◽  
...  
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Cell Density ◽  
Soil Extract ◽  
Forest Reserve ◽  
Extract Concentration ◽  
Increment Of Growth ◽  
Optimal Value ◽  
Significant Increment ◽  
Microalgae Growth

Abstract Recent studies have shown that extracted soil has the potential to enhance microalgae growth. An experiment was conducted, and a kinetic model was developed to understand and predict the growth rate of Dunaliella primolecta with consideration of soil extract effects. Dunaliella primolecta was cultured and mixed with extracted soil from the Raja Musa Forest Reserve, Malaysia. At present, no model of microalgal growth associated with the soil extract effect has been developed to predict cell density and growth rate. A mathematical model was derived to describe the growth rate and cell density production of microalgae with soil extract in the cultured microplate. The prediction model of microalgae concentration agrees with the experimental data, with R2 ranging from 0.94 to 0.98. Culturing microalgae with 1% of soil extract concentration yielded a significant increment of growth rate. However, the growth rate remained constant at a higher concentration, suggesting the percentage as an optimal value. Thus, the soil extract acts as a growth enhancer that doubles the growth rate of cultured microalgae. A parametric study was conducted to characterize the light intensity and temperature effect on the growth model concerning soil extract effect.

Diffusion model for deposition of epitaxial GaAs layers prepared by the MOCVD method

1991 ◽  
Vol 56 (10) ◽  
pp. 2020-2029
Author(s):  
Jindřich Leitner ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma ◽  
Rudolf Hladina
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Kinetic Model ◽  
Gas Phase ◽  
Substrate Surface ◽  
Deposition Process ◽  
Hydrogen Atmosphere ◽  
Epitaxial Gaas ◽  
Kinetics Of ◽  
Good Agreement

The authors proposed and treated quantitatively a kinetic model for deposition of epitaxial GaAs layers prepared by reaction of trimethylgallium with arsine in hydrogen atmosphere. The transport of gallium to the surface of the substrate is considered as the controlling process. The influence of the rate of chemical reactions in the gas phase and on the substrate surface on the kinetics of the deposition process is neglected. The calculated dependence of the growth rate of the layers on the conditions of the deposition is in a good agreement with experimental data in the temperature range from 600 to 800°C.

Bioprocess optimisation for high cell density endoinulinase production from recombinant Aspergillus niger

2021 ◽  
Author(s):  
Pfariso Maumela ◽  
Shaunita Rose ◽  
Eugene van Rensburg ◽  
Annie Chimphango ◽  
Johann Gorgens
Keyword(s):  
Growth Rate ◽  
Aspergillus Niger ◽  
Cell Density ◽  
Enzyme Production ◽  
High Cell Density ◽  
Nitrogen Concentration ◽  
High Cell ◽  
Feed Concentration ◽  
Volumetric Activity ◽  
Activity Increase

Abstract Endoinulinases gene was expressed in recombinant Aspergillus niger for selective and high-level expression using an exponential fed-batch fermentation. The effects of the growth rate (µ), glucose feed concentration, nitrogen concentration and fungal morphology, on enzyme production were evaluated. A recombinant endoinulinases with a molecular weight of 66 KDa was secreted. Endoinulinases production was growth associated at µ> 0.04 h -1 , which is characteristic of the constitutive gpd promoter used for the enzyme production. The highest volumetric activity (670 U/ml) was achieved at a growth rate of 93% of µ max (0.07 h -1 ), while enzyme activity (506 U/ml) and biomass substrate yield (0.043 g biomassDW /g glucose ) significantly decreased at low µ (0.04 h -1 ). Increasing the feed concentration resulted in high biomass concentrations and viscosity, which necessitated high agitation for improved mixing and oxygen. However, the high agitation and low DO levels (ca. 8% of saturation) led to pellet disruption and growth in mycelial morphology. Enzyme production profiles, product (Y p/s ) and biomass (Y x/s ) yield coefficients were not affected by feed concentration and morphological change. The gradual increase in the concentration of nitrogen sources showed that, a nitrogen limited culture was not suitable for endoinulinases production in recombinant A. niger. Moreover, the increase in enzyme volumetric activity was still directly related to an increase in biomass concentration. An increase in nitrogen concentration, from 3.8 to 12 g/L, resulted in volumetric activity increase from 393 to 670 U/ml, but the Y p/s (10053 U/g glucose ) and Y x/s (0.049 g biomasDWs /g glucose ) did not significantly change. The data demonstrated the potential of recombinant A. niger and high cell density fermentation for the development of largescale endoinulinases production system.

Interpretation of Experimental Data with Regard to the Activated Sludge Model No.1 and Calibration of the Model for Municipal Wastewater Treatment Plants

1992 ◽  
Vol 25 (6) ◽  
pp. 167-183 ◽  
Author(s):  
H. Siegrist ◽  
M. Tschui
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Municipal Wastewater Treatment ◽  
Activated Sludge Model

The wastewater of the municipal treatment plants Zürich-Werdhölzli (350000 population equivalents), Zürich-Glatt (110000), and Wattwil (20000) have been characterized with regard to the activated sludge model Nr.1 of the IAWPRC task group. Zürich-Glatt and Wattwil are partly nitrifying treatment plants and Zürich-Werdhölzli is fully nitrifying. The mixing characteristics of the aeration tanks at Werdhölzli and Glatt were determined with sodium bromide as a tracer. The experimental data were used to calibrate hydrolysis, heterotrophic growth and nitrification. Problems arising by calibrating hydrolysis of the paniculate material and by measuring oxygen consumption of heterotrophic and nitrifying microorganisms are discussed. For hydrolysis the experimental data indicate first-order kinetics. For nitrification a maximum growth rate of 0.40±0.07 d−1, corresponding to an observed growth rate of 0.26±0.04 d−1 was calculated at 10°C. The half velocity constant found for 12 and 20°C was 2 mg NH4-N/l. The calibrated model was verified with experimental dam of me Zürich-Werdhölzli treatment plant during ammonia shock load.

scholarly journals Dynamic of the Accelerated Expansion of the Universe in the DGP Model

2011 ◽  
Vol 21 (3) ◽  
pp. 253 ◽  
Author(s):  
Vo Quoc Phong
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Cold Dark Matter ◽  
Growth Index ◽  
Cosmic Acceleration ◽  
Accelerated Expansion ◽  
Density Parameter ◽  
Type Ia ◽  
Age Of The Universe ◽  
The Universe

According to experimental data of SNe Ia (Supernovae type Ia), we will discuss in detial dynamics of the DGP model and introduce a simple parametrization of matter $\omega$, in order to analyze scenarios of the expanding universe and the evolution of the scale factor. We find that the dimensionless matter density parameter at the present epoch $\Omega^0_m=0.3$, the age of the universe $t_0= 12.48$ Gyr, $\frac{a}{a_0}=-2.4e^{\frac{-t}{25.56}}+2.45$. The next we study the linear growth of matter perturbations, and we assume a definition of the growth rate, $f \equiv \frac{dln\delta}{dlna}$. As many authors for many years, we have been using a good approximation to the growth rate $f \approx \Omega^{\gamma(z)}_m$, we also find that the best fit of the growth index, $\gamma(z)\approx 0.687 - \frac{40.67}{1 + e^{1.7. (4.48 + z)}}$, or $\gamma(z)= 0.667 + 0.033z$ when $z\ll1$. We also compare the age of the universe and the growth index with other models and experimental data. We can see that the DGP model describes the cosmic acceleration as well as other models that usually refers to dark energy and Cold Dark Matter (CDM).

scholarly journals Vegetative growth of Umbrella Leaf Palm, Johannesteijsmannia lanceolata in Angsi Forest Reserve, Malaysia

1970 ◽  
Vol 12 ◽  
pp. 11-20
Author(s):  
M. Z. Rozainah ◽  
U. R. Sinniah
Keyword(s):  
Growth Rate ◽  
Key Words ◽  
Vegetative Growth ◽  
Forest Reserve ◽  
Vegetative Phenology

A study of an acaulescent palm, Johannesteijsmannia  lanceolata J. Dransfield was carried out in Angsi Forest Reserve Negeri Sembilan Malaysia for a period of 19 months A total of 32 adults, 24 juveniles and 32 seedlings from 3 different plots were censused every two weeks. The results showed that the average numbers of new leaves entering the crown with in the study period (19months) were: 3.3, 2.6 and 1.3 for 2.1, 1.6 and 0.8 leaves per year for adult juvenile and seedling, respectively. From the calculation it was discovered that the time spent by each leaf in the crown before it died was 8.8 years for adult and 8.4 years for juvenile. Key words: Johannesteijsmannia; Growth rate; Vegetative phenology; Arecaceae doi: 10.3126/eco.v12i0.3190 Ecoprint: An International Journal of Ecology 12: 11-20, 2005

Density-Dependent Growth Adaptation Kinetics in 3T 3 Cell Populations Following Sudden [Ca2+] and Temperature Changes. A Comparison with SV40-3T3 Cells

1979 ◽  
Vol 34 (3-4) ◽  
pp. 279-283 ◽  
Author(s):  
Jürgen van der Bosch ◽  
Ilse Sommer ◽  
Heinz Maier ◽  
Willy Rahmig
Keyword(s):  
Growth Rate ◽  
Cell Density ◽  
Cell Number ◽  
Cell Populations ◽  
3T3 Cells ◽  
Density Dependent ◽  
Cell Densities ◽  
Dependent Growth ◽  
Growth Adaptation ◽  
Stationary Cell

Abstract Lowered extracellular [Ca2+] causes low growth rates and low stationary cell densities in 3T3 cell cultures as compared to physiological [Ca2+]. Under otherwise constant conditions the extra­ cellular [Ca2+] determines a stable stationary cell density, which can be readied by increase of net cell number or decrease of net cell number, depending on cell density at the time of [Ca2+] adjustment. SV40-3T3 cells do not show this [Ca2+] dependency. At 39 °C 3T3 and SV40-3T3 cell populations show an increased growth rate at low cell densities as compared to cell populations at 35 °C. Approaching the stationary density the growth rate of both cell sorts is reduced faster at 39 °C than at 35 °C, leading to lower stationary cell densities at 39 °C than at 35 °C. A temperature change from 39 °C to 35 °C or in the opposite direction can affect the stationary cell density of 3T3 cell populations only if applied before reduction of growth rate by density-dependent growth-inhibiting principles has taken place.

scholarly journals Mathematically modelling inflammation as a promoter of tumour growth

2020 ◽  
Vol 37 (4) ◽  
pp. 491-514 ◽  
Author(s):  
Kathleen P Wilkie ◽  
Farjana Aktar
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Mouse Model ◽  
Tumour Growth ◽  
Surgical Removal ◽  
Cancer Therapies ◽  
Tumour Control ◽  
Small Tumour ◽  
Metastatic Burden ◽  
Anti Inflammatory

Abstract Inflammation is now known to play a significant role in tumour growth and progression. It is also difficult to adequately quantify systemic inflammation and the resulting localized effects in cancer. Here, we use experimental data to infer the possible contributions of inflammation in a mouse model of cancer. The model is validated by predicting tumour growth under anti-inflammatory treatments, and combination cancer therapies are explored. We then extend the model to consider simultaneous tumour implants at two distinct sites, which experimentally was shown to result in one large and one small tumour. We use this model to examine the role inflammation may play in the growth rate separation. Finally, we use this predictive two-tumour model to explore implications of inflammation on metastases, surgical removal of the primary and adjuvant anti-inflammatory treatments. This work suggests that improved tumour control can be obtained by targeting both the cancer and host, through anti-inflammatory treatments, including reduced metastatic burden post-surgical removal of primary tumours.

The evolution and bifurcation of a pendant drop

1994 ◽  
Vol 278 ◽  
pp. 83-100 ◽  
Author(s):  
R. M. S. M. Schulkes
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Satisfactory Agreement ◽  
Growth Rates ◽  
Pendant Drop ◽  
Large Growth ◽  
Comparison With Experimental Data

In this paper we calculate how a pendant drop evolves at the end of a nozzle when the volume of the drop increases steadily with time. We find that the character of the evolution is strongly dependent on the growth rate of the drop and the radius of the nozzle. Typically we find that once the drop has become unstable, two bifurcations occur shortly after each other when the growth rate of the drop is slow. For large growth rates the bifurcations are well-separated in time. We are able to calculate the volumes of the drops after the bifurcations. A comparison with experimental data shows a satisfactory agreement.

Using ozonation to eliminate the inhibition of soluble algal products (SAP) of Scenedesmus sp. LX1 on its growth in microalgal cultivation for biomass/bioenergy production

2015 ◽  
Vol 15 (5) ◽  
pp. 1034-1039 ◽  
Author(s):  
Lin-Lan Zhuang ◽  
Yin-Hu Wu ◽  
Xiao-Jie Shi ◽  
Tian-Yuan Zhang ◽  
Hong-Ying Hu
Keyword(s):  
Growth Rate ◽  
Recycled Water ◽  
Acid Base ◽  
Oxidation Treatment ◽  
Base Property ◽  
Microalgal Cultivation ◽  
Bioenergy Production ◽  
Algal Products ◽  
Microalgae Growth ◽  
Acid Base Property

Water recycling is an effective way to reduce water consumption in the industrialization of microalgae-based biomass/bioenergy production. The soluble algal products (SAP) which inhibit the microalgae growth will accumulate in the recycled water. Therefore, the ozone oxidation treatment of SAP produced by Scenedesmus sp. LX1 was studied to reduce the inhibition of SAP. The experimental results showed that there was almost no change in the content of SAP (counted by dissolved organic carbon) after ozonation, but the inhibition of SAP on microalgae growth disappeared. The intrinsic growth rate (r) of Scenedesmus sp. LX1 in the cultivation solution containing untreated SAP was 0.52 d−1, and it rose to 0.95 d−1 after SAP was ozonized. The maximum population growth rate (Rmax) followed a similar trend, increasing from 9.19 × 105 to 13.0 × 105 cells mL−1 d−1. It was suggested that the changes of fluorescence and hydrophilic–hydrophobic/acid–base property of SAP after ozonation leads to the disappearance of SAP inhibition on microalgae growth.

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