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

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.

Effect of Liquid Viscosity and Flow Orientation on Initial Waves in Annular Gas–Liquid Flow

The complex wave structure of annular gas–liquid flow with disturbance waves and liquid entrainment is a result of the evolution of high-frequency initial waves, appearing at the very inlet of the flow, prior to the hydrodynamic stabilization of liquid film. This stage of flow evolution is studied experimentally, using a shadow technique, and theoretically, using a linear stability analysis of the Orr–Sommerfeld equation in both phases. The present work is focused on the comparison of earlier results obtained in air–water downward flow with the new results obtained in upward flow and with more viscous liquids. The flow orientation affects the shape of the liquid film prior to stabilization; the initial film area is thicker but shorter in upward flow. Upward flow orientation also leads to a lower frequency and the increment of growth of initial waves. The viscosity effect is found to be weak if flow rates of both phases are the same. The model is mostly able to reproduce the qualitative trends, but the quantitative agreement is not reached. Experimental observations indicate that the liquid flow within the initial area is significantly different from the stabilized flow of gas-sheared liquid film, which is used in the model. This difference could explain the discrepancy; further development of the model should be aimed at taking into account the evolution of the velocity profile inside the liquid film during the stage of hydrodynamic stabilization.

Experimental study on evolution law for particle breakage during coal and gas outburst

Coal and gas outburst is a dynamic phenomenon in underground mining engineering that is often accompanied by the throwing and breakage of large amounts of coal. To study the crushing effect and its evolution during outbursts, coal samples with different initial particle sizes were evaluated using a coal and gas outburst testing device. Three basic particle sizes, 5–10 mesh, 10–40 mesh, and 40–80 mesh, as well as some mixed particle size coal samples were used in tests. The coal particles were pre-compacted at a pressure of 4 MPa before the tests. The vertical ground stress (4 MPa) and the horizontal ground stress (2.4 MPa) were initially simulated by the hydraulic system and maintained throughout. During the tests, the samples were first placed in a vacuum for 3 h, and the coal was filled with gas (CH4) for an adsorption time of approximately 5 h. Finally, the gas valve was shut off and the coal and gas outburst was induced by quickly opening the outburst hole. The coal particles that were thrown out by the outburst test device were collected and screened based on the particle size. The results show the following. (1) Smaller particle sizes have a worse crushing effect than larger sizes. Furthermore, the well-graded coal particles are weakly broken during the outburst process. (2) As the number of repeated tests increases, the relative breakage index grows; however, the increment of growth decreases after each test, showing that further fragmentation becomes increasingly difficult.

EFFECT OF CULTIVARS, GROWTH REGULATOR AND SUB-CULTURE ON THE PLANTLET SHOOTS FORMATION AND RAPD ANALYSIS OF STRAWBERRY CULTURES IN VITRO

This experiment amid to study the effect of cultivars, growth regulator and number of sub-cultures on the shoots formation of strawberry plantlets during multiplication stage and Random amplified polymorphic DNA (RAPD) analysis of strawberry cultures in vitro during the fourth sub-culture. This experiment included 40 treatments, which were the combination between two strawberry cultivars (Festival and Sweet Charlie), five treatments of growth regulator (BA and GA3) and four number of sub-cultures during shoots formation (multiplication stage). The obtained results showed that, the maximum increment of growth measurement of strawberry plantlets were recorded by Sweet Charlie cultivar .In addition , using ½ MS-medium without supplemented with any growth regulators (BA and GA3) being the superior treatment for increasing both number of leaves per shoot and shoot length. On the other hand, generally, the fourth sub-culture being the most effective treatment on the growth measurement of strawberry plantlets during multiplication stage. Furthermore, Random amplified polymorphic DNA (RAPD) analysis varied according to the two tested cultivars and the type of for production of disease resistant plants and in plant breeding and crop improvement programs (Mohamed, 2003).

Preparation and Microstructural Properties of Gallium Doped Zinc Oxide Thin Films for Organic Solar Cells

Transparent conducting gallium doped zinc oxide (GaZnO) films were prepared by magnetron sputtering technique. The influence of growth temperature on the microstructural and optical properties of the films were investigated by means of X-ray diffraction (XRD), spectrophotometer and optical characterization method, respectively. The results show that all the samples are polycrystalline in nature having a hexagonal wurtzite type crystal structure with a preferred grain orientation in the (002) direction. The growth temperature significantly affects the crystal structure and optical properties of the samples. The film deposited at the growth temperature of 670 K possesses the largest grain grain, the minimum dislocation density and the lowest microstrain. The average visible transmittance and optical energy gap of the samples increase gradually with the increment of growth temperature.

Synthesis of Monodisperse CdSe QDs Using Controlled Growth Temperatures

This paper reports on the effect of growth temperatures on optical properties of monodisperse CdSe QDs synthesized via wet chemical method. The growth temperature was varied from 260 – 310 °C while growth period was fixed at 60 s. The resulting colloidal was in strong quantum confinement regime and having yield as high as 53%. As the growth temperature increased, the monodispersed CdSe QDs with diameter in the range of 3-7 nm were obtained. Both absorption and PL spectra of the QDs revealed a strong red-shift with the increment of growth temperature. Thus, the size of QDs was enlarged with increment of the wavelength from both the spectra. Consequently, the energy gap of resulting QDs can be tuned by tuning the size of QDs. More importantly, the narrow widths of the PL emissions with different colors make these colloidal to be a potential candidate for different optical and optoelectronic devices.

Concentration of phosphoribosyl pyrophosphate in renal hypertrophy. Contrasting effects of early diabetes and unilateral nephrectomy

Studies were made of the renal phosphoribosyl pyrophosphate (PPRibP) content and PPRibP synthetase (EC 2.7.6.1) activity in rats diabetic for 5, 14 or 20 days, or unilaterally nephrectomized (UN) for 5 days, and in doubly lesioned animals. Approximately equal degrees of renal enlargement were found after 5 days diabetes or 5 days UN. In the doubly lesioned animals the increment of growth was additive. Unilateral nephrectomy of 5 days duration, in contrast with diabetes, had no effect on the PPRibP content of the contralateral kidney, nor did it modify the renal PPRibP content when performed on animals diabetic for 5, 14 or 20 days. The activity of PPRibP synthetase was unaffected by diabetes, UN or diabetes +UN. The results pinpoint a stage of nucleotide synthesis which is differentially affected by the two stimuli, in line with evidence for differences in regulation of nucleic acid turnover in the two conditions.

A dynamic model for the effects of soil and weather conditions on nitrogen response

SUMMARYA dynamic model was derived to predict crop response to nitrogen fertilizer under different soil and weather conditions. It combined formulae representing existing principles about important processes such as leaching of nitrate through soil and nitrate uptake by plant roots. Starting values were given for the initial plant weight and its nitrogen content and parameters were included for the crop's growth and rooting characteristics under optimum growing conditions. For each day the model re-calculated the distribution of water, nitrate and roots down the soil profile and the increment of growth.The validity of the model was tested by using it to forecast the effects of different weather conditions and cultural practices on the nitrogen responses of a test crop, lettuce, when grown in experiments that were entirely independent of those used to obtain parameter values for the model. It successfully predicted the effects on the general shape of the response curve of the distribution of rainfall during the growing season, the age of the plant, the depth of fertilizer incorporation and the application of the nitrogen partly as a top dressing instead of entirely as a base dressing.The model was used to develop a strategy for nitrogen fertilizer practice for lettuce in the U.K. which was found to be broadly in agreement with the results of fertilizer experiments on grower's holdings.

The Effect of Temperature on the Development of the Eggs and Larvae of the Cut-throat Trout (Salmo clarkii clarkii Richardson)

1. The eggs of the cut-throat trout (Salmo clarkii clarkii Richardson) were raised from fertilisation through hatching at constant temperatures of 11.3, 8.25 and 6.35°C. These temperatures are well within the limits of normal development of cut-throat trout. 2. The temperature is not the limiting factor in determining the length of the hatching period, because there are a number of other factors that may cause eggs to hatch either prematurely early or abnormally late, and thus the use of the hatching period as a comparable stage of development for eggs raised at different temperatures may result in error. 3. The average size of cut-throat trout embryos at the moment of hatching was smaller at the higher temperatures and larger at the lower temperatures. 4. The maximum increment of growth in the cut-throat trout occurred about the 41st day at 8.25°C. and about the 28th day at 11.3°C. 5. The percentage of dry weight of the cut-throat trout embryos showed a steady decrease from about 25 to 14 per cent., while that of the yolks showed an increase from about 46 to 55 per cent. 6. Cut-throat trout embryos absorbed water from the yolk and also, at a faster rate, from the environment, both somewhat before and after hatching, so that the percentage of wet weight of the larvae was steadily increasing up to the time the experiment was completed.