Nanostructured Cerium oxide (Ceria): Electrolyte for IT-SOFC | Author : Syed Ismail Ahmad | Abstract | Full Text | Abstract :Mg and Sm co-doped ceria samples Ce0.8Sm0.2-xMgxO2-d (x = 0.00; 0.05; 0.1; 0.15, 0.175) successfully synthesized by Sol-gel route using citric acid as fuel. Sample pellets were sintered at 1300ºC for 4h in air. Bulk density was determined by Archimedes method. X-ray diffraction confirms the single phase cubic fluorite structure. Relative found increasing with increasing Mg content in samarium doped ceria material. The Mg substitution has led to increase crystallite size as determined by XRD data using Scherer’s formula. The alkali earth Mg can be used as sintering aid in ceria-based materials. Dense solid solution of ceria are good candidate electrolyte materials for IT-SOFC. |
| Design and Operation of Low Energy Consumption Passive Human Comfort Solutions | Author : Abdeen Mustafa Omer | Abstract | Full Text | Abstract :The use of renewable energy sources is a fundamental factor for a possible energy policy in the future. Considering the sustainable character of most of renewable energy technologies, they are able to preserve resources and to provide security, diversity of energy supply and services, virtually without environmental impact. Sustainability has acquired great importance due to the negative impact of various developments on environment. The rapid growth during the last decade has been accompanied by active construction, which in some instances neglected the impact on the environment and human activities. Policies to promote the rational use of electric energy and to preserve natural non-renewable resources are of paramount importance. Low energy design of urban environment and buildings in densely populated areas requires consideration of wide range of factors, including urban setting, transport planning, energy system design and architectural and engineering details. The focus of the world’s attention on environmental issues in recent years has stimulated response in many countries, which have led to a closer examination of energy conservation strategies for conventional fossil fuels. One way of reducing building energy consumption is to design buildings, which are more economical in their use of energy for heating, lighting, cooling, ventilation and hot water supply. Consumption of the primary energy will be reduced by following natural or hybrid ventilation, some Passive measures compared to air-conditioning. Fossil fuels dependency will be reduced by the utilization of renewable energy in agricultural greenhouses and buildings. Thus, promotion of the novel renewable applications and its fortification resulting in the preservation of the ecosystem. This will also contribute to the amelioration of environmental conditions by replacing conventional fuels with renewable energies that produce no air pollution or greenhouse gases. Present study described about various low energy building designs and explains the effects of dense urban building on energy consumption and in the climatic changes. Moreover, this study outlines some measures to save energy in buildings. |
| Parametric Structural Schematic Diagram of Electroelastic Actuator for Nanodisplacement | Author : Sergey Mikhailovich Afonin | Abstract | Full Text | Abstract :The parametric structural schematic diagram of the electroelastic actuator or the piezoactuator is determined in contrast the electrical equivalent circuit Cady or Mason types for the calculation of the piezoelectric transmitter and receiver, the vibration piezomotor with the mechanical parameters in form the velocity and the pressure. The structural diagram of electroelastic actuator is obtained with the mechanical parameters the displacement and the force. In this work the method of mathematical physics is used. The transfer functions of the electroelastic actuator are determined. The generalized structuralparametric model, the generalized parametric structural schematic diagram, the generalized matrix equation for the electroelastic actuator nanodisplacement are obtained. The deformations of the electroelastic actuator for the nanotechnology are described by the matrix equation. |
| Study on the In-vitro Release Kinetics of Olmesartan-loaded Optimized Solid Lipid Nanoparticles | Author : Ndidiamaka Hannah Okorie, Chika J Mbah | Abstract | Full Text | Abstract :Drugs with low aqueous solubility not only give low oral bioavailability but provide high inter-and intra-subject variability. Solid lipid nanoparticles (SLN) have gained much interest as potential drug carriers for lipophilic drugs. Olmesartan medoxomil has very poor aqueous solubility and belongs to Class II drugs under Biopharmaceutical Classification Systems. The objective of the present study is to determine release kinetics of Olmesartan medoxomil- loaded solid lipid nanoparticles. Olmesartan medoxomil-loaded solid lipid nanoparticles was prepared by hot homogenization and ultra-sonication method. Particle size, polydispersity index, shape and surface morphology were used to characterize the formulations. The degree of encapsulation of the drug in the formulations was estimated by determining the drug entrapment efficiency. The in-vitro drug release from the formulations was studied using dialysis membrane. The drug release kinetics of the formulation was analyzed using different kinetics models. The results show that the formulations are spherical in shape with smooth surface and possess particle size range of 122.8-135.0 nm, polydispersity index range of 0.208-0.239. The entrapment efficiency was in range of 94.5-96.8%. Fourier transform infrared spectroscopy (FTIR) and differential scanning colorimetry (DSC) test results are considered to be satisfactory. The in-vitro drug release study demonstrated that drugloaded formulations possessed controlled drug release characteristics. The kinetics release results suggest the possible mechanism of action for the drug release might be diffusion of the drug from the formulation. Zero-order drug release kinetics model out of the models investigated, best fitted the in-vitro release data. |
| Surface Properties of PET Polymer Treated by Plasma Immersion Techniques for Food Packaging | Author : Péricles Lopes Sant’Ana | Abstract | Full Text | Abstract :In this work, it was used a vacuum system on a set up well exploited, in order to use Plasma Immersion Ion Implantation (PIII) and Plasma Immersion (PI cathode or PI anode), which were suitable techniques for the surface treatment over the Polyethylene Terephthalate (PET) substrates, from Coke bottles of 2 LTM. The purpose was: to change their wettability, surface morphology and optical transmittance at visible light. Some papers regard the physic-chemical alterations on the surface of PET samples. However, the selectivity of those plasma treatments, results in a notable and partial combination of surface properties, even with serious restrictions. It’s reasonable to reveal the results founded here, using nitrogen and fluorine plasmas, since exposing the sample holder at the room temperature during the treatment time of 900 s. The Origin software 8.0 fitted the graphs that show: The evolution of surface wettability behavior depends on the plasma technique applied and the gas employed to them. In some cases, the surface hydrophilization was not stable as seen by the temporal evolution of the contact angles measurements, O (t). By the AFM images, it is possible to view a mild modification of the PET surface immersed in the plasma, whereas: roughness Rz, increased only a few tens of nanometers, in relation to the virgin PET (1.8 nm), even in a strong ion bombardment during the treatment. As a general trend, the roughness increases slightly for all techniques. Finally, gain or loss of optical transmission, T (?), at visible radiation, depends on the parameters of the plasma treatment. PIII technique and N2 bombardment are more indicated than the plasma immersion and SF6 bombardment to increase the transmittance of PET at visible region. In general, those parameters selected imply in a positive plasma conditions, considering the overview to try out a technological destination for recycled commercial polymers. |
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