Application of ZnO–NiO greenly synthesized nanocomposite adsorbent on the elimination of organic dye from aqueous solutions: Kinetics and equilibrium

Organic dyes are discharged into aquatic systems from several industries causing severe environmental problems and toxicity to aquatic life. Therefore, it should be removed from water with a suitable process. Among several treatment processes, adsorption is one of the most attractive because of its simplicity, efficiency, and low operating cost. Moreover, adsorption supports environmental sustainability if a suitable adsorbent is used. In this work, a green route was followed to prepare ZnO: NiO nanocomposites using the Neem leaf extract as a stabilizing agent instead of harmful chemicals. Four different samples with three different ZnO:NiO ratios were prepared, namely: 3Z:1 N, 1Z:1 N, 1Z:3 N and 1Z:1 N without extract. The samples were characterized by XRD, TEM, SEM, IR, and UV, which all confirmed the successful synthesis of the nanocomposites. The nanocomposites were used for the adsorption of methyl orange (MO) from aqueous solutions. The four nanocomposites prepared with the aid of the extract showed a high sensitivity with 100% removal of MO from 6.25 ppm solutions. Furthermore, all the samples have a relatively fast kinetic with an equilibrium time less than 1 h. Also, the three samples maintained 100% removal efficiency after 5 adsorption-desorption cycles. The difference in particle size distribution obtained for the 1Z:1 N prepared with and without the extract confirms the important rule of the extract as a capping agent with an average size of 18 nm for the sample with the extract and 88 nm for the sample prepared without the extract. This difference in the particle sizes has been reflected on the adsorption performance of the two samples with a maximum adsorption capacity of 33 mg/g for the sample prepared with the extract compared to 6 mg/g for the sample without the extract.     

Human Body Shadowing at 28 GHz

Wireless Personal Communications - It is well known that human body shadowing is a significant propagation effect in indoor communications especially at frequencies higher than 10 GHz....     

UWB Fractal Antennas with Low Group Delay Variation

Wireless Personal Communications - It is well known that the safety, reliability and energy efficiencies are the prime concerns while designing and deploying wireless sensor networks. Therefore,...     

Optomechanical investigating the impact of grafting polyamide-6 fibers with PMMA on its intrinsic optical properties

An optomechanical characterization was carried out to investigate the influence of grafting polyamide-6 fibers with poly (methyl methacrylate) (PMMA) on their structural relationship properties. Intrinsic optical properties of the modified sample were determined using a method based on the cold drawing process. The Mach-Zehnder interferometer attached with mechanical drawing device was used to determine the refractive indices and birefringence of the polyamide-6 samples at different draw ratios. A graphical method was used to determine the intrinsic birefringence of modified polyamide-6 with PMMA and it was found to be 0.0673 which is less than pure polyamide-6. The resulting data was used to estimate some structural parameters such as the orientation function, optical orientation angle and structural constant. The drawing effect is more significant on the modified sample than on the pure sample. It was found that the grafting process produced a material with new properties that can be used in different applications.     

A Complex Network Methodology for Travel Demand Model Evaluation and Validation

Networks and Spatial Economics - Travel demand can be viewed as a weighted and directed graph where nodes are the origins and destinations and links represent the trips between nodes. This paper...     

IFN-gamma and IL-12 are increased in active compared with inactive tuberculosis

Cytokine-mediated immune responses to Mycobacterium tuberculosis infection are important determinants of M. tuberculosis disease development and pathology. However, the distinction between changes in cytokine profile attributable to M. tuberculosis infection and those associated with active pulmonary tuberculosis is unclear. We have compared T cells and their subsets, macrophages, and cytokine messenger RNA (mRNA) profile in the bronchoalveolar lavage (BAL) of patients with active pulmonary tuberculosis with inactive tuberculosis subjects. Ten patients with microbiologically confirmed active pulmonary tuberculosis and 25 subjects with inactive tuberculosis were recruited. Bronchoscopy with BAL was undertaken in all cases and BAL cytospins were examined using the techniques of immunocytochemistry and in situ hybridization. There was a significant increase in the percentage of BAL cells that were CD8+ T cells in active tuberculosis compared with inactive tuberculosis (mean +/- SEM: 7.2 +/- 0.9 versus 2.1 +/- 0.4, p < 0.001), but not CD3+ or CD4+ T cells nor macrophages. There were significant increases in the percentage of BAL cells expressing mRNA for interferon-gamma (IFN-gamma) and interleukin-12 (IL-12) in active versus inactive pulmonary tuberculosis subjects (8.0 +/- 0.6 versus 3.7 +/- 0.4 and 28.4 +/- 2.3 versus 10.2 +/- 1.0, p < 0.001, respectively). There were no significant differences between the active and inactive groups in the number of cells expressing mRNA for IL-2, tumor necrosis factor-alpha (TNF-alpha), IL-4, and IL-5. In conclusion, active pulmonary tuberculosis is associated with increased numbers of CD8+ cells and marked increases in the expression of IL-12 and IFN-gamma mRNA in the BAL, both of which may be useful markers of disease activity.     

Cooling of water flowing through a night sky radiator

Experimental and theoretical studies of nocturnal cooling of water flowing through a night sky radiator unit were carried out. The system used for this study is two parallel plates night sky radiator with the top one (radiator) being a painted black aluminum plate. The radiator plate was covered by a polyethylene windscreen cover. The experimental study was conducted for a gravity flow open loop system. The parameters studied include the effect of average water mass flow rate, uncovered from the ambient versus covered supply warm water tank, and windscreen cover thickness on the performance. A new definition of the performance was expressed by an overall efficiency. A comparison between nocturnal cooling of stagnant and flowing water was also done. In the theoretical study a thorough radiation model was developed which calculates the radiation heat losses from both the cover and the radiator plate considering multiple reflections and absorptions between cover and plate. Energy balance was then applied on the cover, the radiator plate and the water. The cover and insulation were considered one lump each, while each of the radiator plate and the water were divided into discrete number of lumps. Energy storage in the radiator frame and insulation, and water elements was considered. Experimental results were used for verification of the theoretical model.     

Influence of slag substitution on some properties of sand-lime aerated concrete

The effect of substitution of sand with granulated slag on some properties of sand-lime aerated concrete was investigated. The compressive strength, the hydration kinetics and the nature of the hydration products were studied for samples autoclaved under 8 atm for different periods from 0.5 to 24 h. The results indicate that the substitution of slag leads to a marked increase of the compressive strength compared with that of the unsubstituted samples. The extent of hydration, as measured by the chemically combined water, free lime and free silica contents, is enhanced due to the slag substitution. The X-ray diffraction results show that the hydration products are mainly tobermorite-like phases, C₄AH₁₃,C₃AH₆ and CAH₁₀ in the slag-containing samples. Cement notations are used in the text, e.g. C=CaO, S=SiO₂, A=Al₂O₃ and H=H₂O.     

Determination of drift mobility and carrier concentration in semiconductors using surface acoustic wave amplifier structure

Experimental data are analysed in order to determine the electric field at which the synchronism occurs in a semiconductor piezoelectric amplifier structure. In the interaction region the electron mobility of a sample of high resistivity silicon is measured to be in the order of 1268 cm2/Vs. The carrier concentration is deduced as a result of the comparison between the experimental and theoretical results.     

Inter/intra process communications in ISTS

The complexity of maintaining a generic and flexible Intelligent Simulation-Based Training System (ISTS) necessitates a coordinated methodology to handle inter and intra process communications. Several issues must be considered before committing to one form of process communication. Such issues involve system portability, real time interaction, distributed system realization, memory, and multi-process communications. This document examines the application of different communication strategies to ISTS. The advantages and disadvantages of using memory-based InterProcess Communication (IPC) facilities in SunOS operating system versus the use of properties for communication in an X Window environment are described. Furthermore, the use of rule-based blackboard architecture to handle communications between modules within the Tutoring group is presented. This research provides the ground work for a flexible and generic Intelligent Simulation Training System.