Ergogenic Attributes of Young and Mature Coconut (Cocos nucifera L.) Water Based on Physical Properties,Sugars and Electrolytes Contents

The present work aimed to compare the main ergogenic attributes of two commercialized stages (young and mature) of coconut water (CW) obtained from four coconut varieties. The changes of electrolytes and sugars in CW upon maturation were quantified by inductively coupled plasma mass spectrophotometer and high-performance liquid chromatography, respectively. Based on the electrolyte profiling, potassium yielded the highest amount (ranging from 237.41 to 361.20 mg/100 mL) followed by sodium, magnesium, calcium, iron, manganese, copper, selenium, and zinc across all the maturity stages tested. For sugars, there were lower amounts of fructose and glucose, but a higher amount of sucrose with the maturation of the fruits. In conclusion, the amount of beneficial nutrients in the form of sugars and minerals was higher than that of young CW, and the ergogenic attributes of mature CW especially from MATAG variety (M-MATAG) were the best to be exploited further in the development of natural energy drinks.     

Zooplankton population in the river tigris: Effects of samarra impoundment

The influences of the Samarra impoundment on the ecology of the downstream sector of the river Tigris are investigated. Zooplankton were collected monthly from July 1987 to July 1988. It was found that zooplankton were most abundant during high river discharges in March. During the month of low river discharge, September, the zooplankton population was greatly reduced immediately below the barrage and remained so to the last downstream station. Several factors seem to explain such differences. The high discharge from the impoundment was found to be the dominating factor and may flush the small backwaters in which zooplankton were abundant, thus increasing the population in the river. Zooplankton species vary in their ability to sustain populations in the river, variations which are due mainly to species-specific characteristics.     

Dissolution kinetics of an oxidized copper ore in water saturated by chlorine

Dissolution kinetics of an oxidized copper ore (mainly malachite) in water saturated by Cl₂ has been studied. The effect of particle size, flow rate of the gas, temperature and solid-liquid ratio has been determined. The dissolution rate increased with decrease in particle size and solid-liquid ratio and with increase in the gas flow rate and temperature. It has been found that the dissolution proceeds in two stages and is controlled by diffusion through the ash layer in each stage. The activation energies for the first and second stage are 27.15 and 20.21 kJ mol^?1, respectively.     

Split internal-loop photobioreactor for Scenedesmus sp. microalgae:Culturing and hydrodynamics

In this study, the evaluation of the performance of the split internal loop photobioreactor for culturing a species of green microalgae, Scenedesmus sp. under different operating superficial gas velocity and during a different time of growth (i.e., starting for the first day until end day of the culturing process) was addressed. The evaluation of the performance of the split internal loop photobioreactor was included assessing the density, pH, temperature, vis-cosity, surface tension, the optical density, cell population, dry biomass, and chlorophyll of the culture medium of the microalgae culturing. Additionally, the hydrodynamics of a Split Internal-Loop Photobioreactor with microalgae culturing was comprehensively quantified. Radioactive particle tracking (RPT) and gamma-ray com-puted tomography (CT) techniques were applied for the first time to quantify and address the influence of microalgae culture on the hydrodynamic parameters. The hydrodynamics parameters such as local liquid veloc-ity field, shear stresses, turbulent kinetic energy, and local gas holdup profiles were measured at different super-ficial gas velocities as well as under different times of algae growth. The obtained results indicate that the flow distribution may significantly affect the performance of the photobioreactor, which may have substantial effects on the cultivation process. The obtained experimental data can serve as benchmark data for the evaluation and validation of computational fluid dynamics (CFD) codes and their closures. This, in turn, allows us to develop ef-ficient reactors and consequently improving the productivity and selectivity of these photobioreactors.     

Effect of structure on the glass transition temperatures of linear and crosslinked poly(isobornylacrylate-co-isobutylacrylate)

A series of linear acrylic copolymers based on Isobornyl acrylate (IBOA) and isobutyl acrylate (IsoBA) were elaborated by radical photopolymerization. In addition, several photochemically crosslinked poly(IBOA-co-IsoBA) were prepared by introducing small amounts of 1,6-hexanedioldiacrylate as crosslinking agent. The evolution of the glass transition temperature was determined experimentally by differential scanning calorimetry as a function of composition for both linear and crosslinked poly(IBOA-co-IsoBA), yielding T_g values ranging from (~249) to (~315 K). Theoretical modeling was performed applying Fox, Gordon-Taylor and Couchman-Karasz models by simple calculations using experimental data, leading to only fair agreement between theoretical and experimental values, or by applying fitting procedures involving one or two adjustable parameters. Likewise, the Kwei model, known to take into account hydrogen bonding interactions between monomers, could not describe well the evolution of T_g, indicating the existence of other factors influencing T_g. Finally, a thermodynamic approach based on entropy considerations allowed to attribute an explanation of the evolution of T_g.     

Gamma irradiation-induced modifications in the structural,thermal, and optical properties of polyvinyl alcohol-polyethylene glycol/cobalt oxide nanocomposite films

Cobalt oxide nanoparticles (NPs) are highly consistent dispersed into the blend polymers rather than other NPs. Also, the ability of polyvinyl alcohol-polyethylene glycol (PVA-PEG) to form homogenous blend attained it essential characteristics that allow it to be suitable candidate for numerous industrial applications. Thus in the present work, Co₃O₄ nano-oxide, was synthesized by the sol-gel procedure and PVA-PEG/Co₃O₄ nanocomposite NCP films were synthesized by the casting technique. Samples from the synthesized NCP were exposed to γ doses between 20 and 230 kGy. The induced alterations in the synthesized NCP due to gamma irradiation have been illustrated using X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA), Fourier transform infrared (FTIR), and UV spectroscopes. Further, Color divergence between the blank and the irradiated films has been estimated. Gamma doses between 60 and 230 kGy lead to the prevalence of intermolecular crosslinking, which enhances the disordered phase. This is reflected in a rise in the degradation temperature values from 225°C to 236°C indicating an improvement in the thermostability of the NCP samples. Moreover, the γ-radiation induces defects that split the ordered portion, reducing T_m from 238°C to 229°C. In addition, the band gap decreases from 5.24 to 4.61 eV with increasing the γ doses to 230 kGy, signifying disorder character. Finally, the NCP samples showed a color change by γ radiation, as ΔE raised with increasing dose. The resultant improvements in the optical properties of the NCP samples allow it to be used in optoelectronic and dosimetric applications.     

Dynamic Adsorption of CO2 from Methane: Studies on Mass and Heat Transfer

Three‐dimensional computational fluid dynamics studies related to dynamics adsorption of CO₂ from natural gas is found to be limited. 3D analyses for dynamics adsorption are substantially crucial to give a better prediction on the adsorption process by considering the actual fluid flow behavior within the packed‐bed porous media. A kinetic adsorption model has been integrated in a commercial fluid dynamics simulator to simulate the 3D hydrodynamics and adsorption phenomenon in a zeolite‐filled packed column for a CO₂‐methane separation system. The effects of various parameters such as Reynolds number, CO₂ feed concentration, feed temperature, and column dimension on CO₂ adsorption efficiency have been investigated. A correlation for adsorption efficiency based on the CO₂ concentration profiles has been developed and validated.     

Chemical vapor deposition synthesis of graphene on copper with methanol, ethanol, and propanol precursors

Large area, high quality graphene was synthesized from different liquid alcohols by chemical vapor deposition on copper foils in a tube furnace. The quality of the synthesized graphene was systematically investigated with various growth conditions. Alcohol vapor exposure times of 5 min and an average growth temperature of 850 °C yield continuous graphene monolayer films, as inferred from Raman spectroscopy. X-ray photoelectron spectroscopy shows that the oxygen moieties found in the source molecules have no measureable doping or oxidation effect in the synthesized graphene. Raman spectroscopy indicates that graphene films transferred to insulating substrates are of high quality. The field effect mobility of large area graphene transistors was measured at room temperature to be in the range 1800–2100 cm²/V s at carrier densities between 10¹¹/cm² and 10¹²/cm².     

Effect of additive concentration and gamma radiation on the molecular and color properties of poly(vinyl chloride)

The effects of addition of different monomers on the molecular properties of poly(vinyl chloride) (PVC) have been studied. Three different additive monomers from N‐phenyl maleimide derivatives were added with the same concentration 0.02 gm/1 gm PVC as stabilizers to PVC. These stabilizers are N‐phenyl maleimide, Para‐carboxy N‐phenyl maleimide, and Para‐amide carboxy N‐phenyl maleimide (PA‐NPMI). Their stabilizing efficiencies were evaluated by measuring the intrinsic viscosity of the solution samples. The results reveal that the type of the additive monomer plays a major role in determining the stabilizing potency of these materials. It was found that the PA‐NPMI is the most effective stabilizer that improves the intrinsic viscosity of pure PVC from 1.02 to 1.19. So, the effect of its addition with different concentrations was studied. The results indicate that the sample with 0.015 gm PA‐NPMI/1 gm PVC has higher intrinsic viscosity. Thus, this sample was chosen to be a subject for further study to investigate the effect of gamma irradiation on its molecular and color properties. Samples from the 0.015 gm PA‐NPMI/1 gm PVC were irradiated with gamma doses in the range 5–100 kGy. It is found that the irradiation in the dose range 20–60 kGy enhances the intrinsic viscosity of the samples. In addition, the transmission of these irradiated samples in the wavelength range 200–2500 nm, as well as any color changes, was studied. The color intensity ΔE was greatly increased with increasing the gamma dose, and was accompanied by darkness with a significant increase in the yellow color component. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

HR 720, a novel angiotensin receptor antagonist inhibits the angiotensin II-induced trophic effects, fibronectin release and fibronectin-EIIIA+ expression in rat aortic vascular smooth muscle cells in vitro

The aim of this study was to evaluate the direct trophic effects of angiotensin II (AII) on rat vascular smooth muscle cells obtained from a single cellular isolate. Cell volume, protein synthesis, fibronectin (FN) release and FN-EIIIA+ mRNA isoform expression were analyzed in parallel. The effects of HR 720, a novel AT1 angiotensin receptor antagonist with some AT2 receptor affinity, were compared with those of selective AT1 antagonist EXP 3174. Both HR 720 and EXP 3174 inhibited in a concentration-dependent manner the maximum increase in cell volume induced by 10(-9) M Sar1-All (IC50 = 0.49 x 10(-9) M and 0.79 x 10(-9) M, respectively). Maximum [3H]leucine incorporation was also achieved at 10(-9) M All. HR 720 blocked the increase in protein synthesis with potency similar to EXP 3174; the respective IC50 values were 1.04 x 10(-9) M and 1.36 x 10(-9) M. All dose-dependently increased FN release, which was also equally inhibited by about 50% with both compounds at 10(-6) M. Furthermore, All enhanced FN-EIIIA+ mRNA in rat vascular smooth muscle cells (VSMC), which indicated a modulation of FN isoform expression which was inhibited by angiotensin II antagonists. In conclusion, All induced parallel and concentration-dependent increases in cell volume, protein synthesis, FN release and FN-EIIIA+ mRNA expression in vascular smooth muscle cells. These effects appeared to be essentially mediated by AT1 receptor stimulation as indicated by the equal inhibitory effects of HR 720 and EXP 3174.