11 research outputs found

    Recent Drifts in pH-Sensitive Reverse Osmosis

    Get PDF
    Preparation of some smart PAm-ZTS pH-responsive membranes, via reactions between ZTS and PAm under different conditions, was conducted for testing pressure-driven reverse osmosis membranes (PDROMs) in active rejection of Ce4+, Pr3+, Sm3+, Gd3+, Dy3+, and Ho3+ ionic lanthanide species in their 3+ and 4+ states. Recent theoretical models to designate the membrane operations were mathematically itemized, after selective characterization of the PDROMs. The pH scale response of the membrane was confirmed using static adsorption and hydraulic pervasion result estimations. The flux across the PAm-ZTS membrane decreased with the lowering pH value, with drastic decreases between pH 4 and 7, and was both reversible and durable with pH shifts between ~3 and ~8. At lower pH 3, the individual pores were in a closed-state due to the prolonged structure of the amide chains on the porous surfaces. In contrast, at pH 8, the higher pH value, the membrane pores were in an open-state format, because of the collapsed structures of the amide chains. This grants a clear possible approach for manufacturing some pH-responsive composite membranes and inspires further design for their stimuli-responsive actions by incorporating molecularly designed macromolecules, synthesized by controlled polymerization

    Review: Current trends in coral transplantation – an approach to preserve biodiversity

    Get PDF
    Ammar MSA,El-Gammal F, Nassar M, Belal A, Farag W, El-Mesiry G, El-Haddad K, Orabi A, Abdelreheem A, Shaaban A. 2013. Review: Current trends in coral transplantation – an approach to preserve biodiversity. Biodiversitas 14: 43-53. The increasing rates of coral mortality associated with the rise in stress factors and the lack of adequate recovery worldwide have urged recent calls for actions by the scientific, conservation, and reef management communities. This work reviews the current trends in coral transplantation. Transplantation of coral colonies or fragments, whether from aqua-, mariculture or harvesting from a healthy colony, has been the most frequently recommended action for increasing coral abundance on damaged or degraded reefs and for conserving listed or “at-risk” species. Phytoplanktons are important for providing transplanted corals with complex organic compounds through photosynthesis. Artificial surfaces like concrete blocks, wrecks or other purpose-designed structures can be introduced for larval settlement. New surfaces can also be created through electrolysis. Molecular biological tools can be used to select sites for rehabilitation by asexual recruits. Surface chemistry and possible inputs of toxic leachate from artificial substrates are considered as important factors affecting natural recruitment. Transplants should be carefully maintained , revisited and reattached at least weekly in the first month and at least fortnightly in the next three months. Studies on survivorship and the reproductive ability of transplanted coral fragments are important for coral reef restoration. A coral nursery may be considered as a pool for local species that supplies reef-managers with unlimited coral colonies for sustainable management. Transplanting corals for making artificial reefs can be useful for increasing biodiversity, providing tourist diving, fishing and surfing; creating new artisanal and commercial fishing opportunities, colonizing structures by fishes and invertebrates), saving large corals during the construction of a Liquified Natural Gas Plant

    Photocatalytic degradation of methylene blue and antibacterial activity of mesoporous TiO2-SBA-15 nanocomposite based on rice husk

    Get PDF
    Concerns have been increased regarding the existence of pollutants in environmental water resources and their risks to the ecosystem and human society. TiO2 photocatalyst is considered as an effective photocatalyst to remove the pollutants. Herein, the mesoporous TiO2-SBA-15 was prepared using the rice husk extract as the silica source. The fabricated nanocomposites were characterized using FTIR, small and wide angle XRD, Raman spectroscopy, UV-vis, BET surface area analysis, and HRTEM. The photocatalytic efficiency of the composites for the degradation of methylene blue (MB) has been evaluated under UV irradiation. Interestingly, due to the excellent dispersion of TiO2 on the wall of SBA-15 and good hydrophilicity, the nanocomposites displayed a good catalytic activity. The higher photodegradation performance was achieved by the composite containing 10 wt% TiO2 by which the MB was fully degraded within 15-20 min of irradiation. Besides, TiO2-SBA-15 could effectively inhibit the growth of Gram-positive and Gram-negative bacteria. These results offer a practical and economic approach in the environmental management industries

    Influence of polymorphisms in candidate genes on carcass and meat quality traits in rabbits.

    No full text
    Candidate gene is a powerful approach to study gene-trait association and offers valuable information for genetic improvement using marker-assisted selection. The current work aimed to study the polymorphisms of four single nucleotide polymorphism (SNPs) at located growth hormone (GH), insulin-like growth factor-II (IGF-II), fat mass and obesity-associated (FTO), and insulin receptor substrate-1 (IRS-1) genes, and their association with the carcass, and meat quality traits in rabbits. The SNPs were genotyped using RFLP-PCR in New Zealand White and local Baladi rabbits. The results revealed that the heterozygous genotype was the most frequent in all cases, except for the FTO SNP in LB rabbits. There was a significant effect for GH genotypes on meat lightness after slaughter and hind-part weight. While, IGF-II mutation significantly affected slaughter, hot carcass, commercial carcass, and hind-part weights. The FTO SNP was associated with cooking loss and intramuscular fat weight, and the IRS-1 SNP was significantly associated with drip loss and intramuscular fat. Specific-breed effects were obtained for IGF-II SNP on cooking loss, and for the intramuscular fat. Although the results suggested that these mutations are useful candidate genes for selection, more research for detecting more variants associated with carcass and meat quality traits in rabbits are recommended

    Novel Porous Organic Polymer for High-Performance Pb(II) Adsorption from Water: Synthesis, Characterization, Kinetic, and Isotherm Studies

    No full text
    The aim of the current study was to develop a novel triphenylaniline-based porous organic polymer (TPABPOP-1) by the Friedel–Crafts reaction for the efficient elimination of Pb(II) from an aqueous environment. XPS, FTIR, SEM, TGA, and 13C CP/MAS NMR analyses were applied to characterize the synthesized TPABPOP-1 polymer. The BET surface area of the TPABPOP-1 polymer was found to be 1290 m2/g. FTIR and XPS techniques proved the uptake of Pb(II) was successfully adsorbed onto TPABPOP-1. Using batch methods, Pb(II) ion adsorption on the TPABPOP-1 was studied at different equilibrium times, pH values, initial Pb(II) concentration, adsorption mass, and temperature. The outcomes exhibited that the optimum parameters were t: 180 min, m: 0.02 g, pH: 5, T: 308 K, and [Pb(II)]: 200 mg/L. Nonlinear isotherms and kinetics models were investigated. The Langmuir isotherm model suggested that the uptake of Pb(II) was favorable on the homogeneous surface of TPABPOP-1. Adsorption kinetics showed that the PFO model was followed. Pb(II) removal mechanisms of TPABPOP-1 may include surface adsorption and electrostatic attraction. The uptake capacity for Pb(II) was identified to be 472.20 mg/g. Thermodynamic factors exhibited that the uptake of Pb(II) was endothermic and spontaneous in standard conditions. Finally, this study provides effective triphenylaniline-based porous organic polymers (TPABPOP-1) as a promising adsorbent with high uptake capacity

    Review: Current trends in coral transplantation -an approach to preserve biodiversity

    No full text
    ABSTRACT Ammar MSA, El-Gammal F, Nassar M, Belal A, Farag W, El-Mesiry G, El-Haddad K, Orabi A, Abdelreheem A, Shaaban A. 2012. Review: Current trends in coral transplantation -an approach to preserve biodiversity. Biodiversitas 13: 00-00. Increasing the rates of coral mortality associated with rise in stress factors and the lack of adequate recovery worldwide have urged recent calls for action by the scientific, conservation, and reef management communities. This work reviews the current trends in coral transplantation. Transplantation of coral colonies or fragments, whether from aqua-, mariculture or harvesting from a healthy colony, has been the most frequently recommended action for increasing coral abundance on damaged or degraded reefs and for conserving listed or "at-risk" species. Phytoplanktons are important for providing transplanted corals with complex organic compounds through photosynthesis. Artificial surfaces like concrete blocks, wrecks or other purpose-designed structures can be introdcued for larval settlement, new surfaces can be also created through electrolysis. Molecular biological tools can be used to select sites for rehabilitation by asexual recruits. Surface chemistry and possible inputs of toxic leachate from artificial substrates are considered as important factors affecting natural recruitment. Transplants should be carefully maintained , revisited and reattached at least weekly in the first month and at least fortnightly in the next three months. Studies on survivorship and the reproductive ability of transplanted coral fragments are important for coral reef restoration. A coral nursery may be considered as a pool for local species that supplies reef-managers with unlimited coral colonies for sustainable management. Transplanting corals for making artificial reefs could be useful in increasing biodiversity; providing tourist diving, fishing and surfing; creating new artisanal and commercial fishing opportunities; colonizing structures by fishes and invertebrates), saving large corals during the construction of a Liquified Natural Gas Plant

    Effective Removal of Malachite Green Dye from Water Using Low-Cost Porous Organic Polymers: Adsorption Kinetics, Isotherms, and Reusability Studies

    No full text
    In this study, triphenylaniline-based porous organic polymers (TPA-POPs) were successfully prepared by the Friedel–Crafts reaction and applied to adsorb malachite green (MG) dye from water. The TPA-POP was characterized using TEM, SEM, FTIR, 13C (CP/MAS) NMR, BET surface area, and XRD analysis. The results exhibited that the TPA-POP has a high surface area (1625.14 m2/g) with pore volume (0.353 cm3/g) and pore radius (1.57 nm) that reflect the high quantity of MG adsorbed on the TPA-POP. The polymer was evaluated as an excellent adsorbent for MG adsorption from water using the batch method. MG dye removal was optimized as 99.60% (at pH: 6.0, adsorbent dosage (m): 0.01 g, temperature (T): 45 °C, and contact time (t): 300 min). The kinetic data follow the Elovich model, while the isotherm data fit the Langmuir model well with uptake capacity (755.72 mg/g) at T: 45 °C. According to thermodynamic parameters, the adsorption process was endothermic and spontaneous. The adsorption of MG on the TPA-POP occurred via different mechanisms (π–π interaction, electrostatic attraction, and hydrogen bonding). Reusability experiments exhibited that the TPA-POP still maintained high removal efficiency (82.12%) after five cycles. In conclusion, the TPA-POP is a promising adsorbent owing to its cost-effectiveness, high adsorption capacity, high surface area, excellent reusability, and efficient MG removal from aqueous media
    corecore