Advanced Materials Research Vols. 463-464

Abstract: Novel assemblies of gold nanoparticles or gold nanoparticles with other inorganic nanoparticles have received considerable interest due to their fascinating properties desired for various detection applications. Here we present a bioconjugate containing ferritin and gold nanoparticles. In this bioconjugate, there is a central ferritin, and a several gold nanoparticles are located around by DNA base-pairing.

Abstract: This work compared the variation of weight of Mg 1%Ca as cast in different concentrations of hydrofluoric acid (HF) such as 45% - 40% - 35% - 25% - 20 % - 13% - 7 % for 24 h at room temperature to be utilized in biomaterial application like hip, knee implants that have effect on corrosion resistance. By immersion Mg 1%Ca alloys in HF, the layer of MgF2 was constituted on the surface of alloy and this layer improves the corrosion and causes weight gain. The results show that in order to get a better corrosion resistance, surface treatment should be done in 40% of HF, because the weight gain is more than other HF concentrations.

Abstract: Artificial bone implant is concerned to improve their substantial features such as biocompatibility and mechanical properties. Ti-Nb alloys were considered to be one of the competitive materials because of their good biocompatibility and pseudoelasticity. In a present work, the effect of Zr addition as a third element on mechanical properties and pseudoelasticity of Ti-Nb alloys with Nb-content of 22-23at% were investigated by using cycling tests. The alloy ingots were fabricated by an arc melting method. The ingots were homogenization treated at 1273 K for 3.6ks followed by cold-rolled to a reduction ratio of 90% in thickness. All specimens were heat-treated at 873 K and some of them were aging treated at temperature ranging from 573 to 673 K after heat-treatment. Pseudoelasticity and mechanical behavior were evaluated by cycling test at room temperature. The results suggested that psuedoelasticity was confirmed in specimens without aging treatment irrespective of alloy compositions. Maximum recovery strain recovery increases with increasing Zr content. From all information acquired, it can be concluded that Ti-22Nb-(3-4)Zr(at.%) and Ti-23Nb-(2-3)Zr(at.%) alloys are the most optimum for artificial bone.

Abstract: Effects of NH4OH, KOH, Ca (OH) 2, CaCO3, and a mixture of CaCO3 and NH4OH as neutralizing agents for efficient recovery of lactic acid fermented by Escherichia coli W were investigated. Maximum productivities of lactic acid were 11.3 g/L, 10.7 g/L, 5.5 g/L, 11.9 g/L, and 12.8 g/L respectively. The mixed neutralizing agent of CaCO3 and NH4OH was testified to be better than any single neutralizer used in this study. CaCO3 was the most appropriate neutralizer among the first four neutralizers, which could make lactic acid precipitate in the form of calcium lactate, and facilitate the downstream separation and extraction of lactic acid. Furthermore, it was a slow type of mild neutralizer and had a limited capacity to regulate pH. NH4OH could regulate pH easily, and it was beneficial to cell growth as an additional nitrogen source, thus resulting in a relatively lower lactic acid production.

Abstract: In this research paper we present a new high efficient three-junction photovoltaic cell with anti-reflective coating. The aim of our research work is to improve the photon absorption and reduce the photon reflection as well as the trasmission. The use of anti-reflective coating (ARC), Gallium-Phosphide-Oxide on the photovoltaic cell based on InGaAs/InGaSb has increased the photon absorption significantly. In this work we have analyzed the photon absorption, photon reflection and photon transmission of existing high efficient solar cells. Real Time Photonics Simulator has been used to simulate the performance of the solar cells. The simulation results show that with the inclusion of Gallium-Phosphide-Oxide on the multi-junction photovoltaic cell the photon absorption increases significantly. Our three-junction photovoltaic cell based on GaPO/In0.53Ga0.47As/In0.5Ga0.5Sb shows dramatic improvement of photon absorption in the range of 479nm – 767nm wavelength of the solar spectrum. With the addition of GaPO in place of GaP we see a tremendous increase of photon absorption, which significantly increases the efficiency of the photovoltaic cell

Abstract: Ultrasonic was employed to improve the functional properties of wheat gluten. The results showed their solubility, emulsifying capacity and emulsion stability index of ultrasonically treated wheat gluten gradually increased as the ultrasonic power and treatment time increase, when ultrasonic treated for 20min at 240W, the solubility, emulsifying capacity and emulsion stability reached the maximum, then the solubility slightly decreased when the ultrasonic power exceeded 240W. However, the forming capacity and foam stability of ultrasonically treated gluten samples gradually increased with ultrasonic power and treatment time increasing. Gel Permeation Chromatography (GPC) observations revealed that the molecular weight of gluten decreased as the ultrasonic power increased, implying that the molecular of wheat gluten was broken by ultrasonic. Lower molecular weight of wheat gluten showed better functional properties.

Abstract: The cooperation becomes an important requirement in distributed Healthcare Information Systems (HISs). It is used to provide patients with a good and fast treatment. To achieve the cooperation feature, a fractal approach has been proposed by many researchers in different areas. Also, many approaches have been proposed in cooperative HISs to share patients’ information between different healthcare centres in order to provide a good treatment. However, most of these researches did not address the required improvement on physician skills and the possible enhancement on the healthcare services. This empirical study proposes a way to adjust fractal approach in HISs in order to improve the cooperation feature among physicians which may enhance both physician skills and healthcare services. The analysis of the collected data shows there are problems that associated with current system and therefore a set of requirements have been initiated. It has been found that there is a need to adapt the fractal features in current HIS environment.

Abstract: Acid stimulation of carbonate formations using hydrochloric (HCl) acid-based systems to improve hydrocarbon production or water injection has been a common practice. The challenge of achieving full zonal coverage with the stimulation fluid still persists. This task is even more difficult in highly slanted layered, naturally fractured reservoirs exhibiting high permeability and porosity contrast. During acid stimulation treatments, the fluid has a natural tendency to take the path of least resistance, penetrating layers with the highest porosity and permeability while little or no acid is injected into lower-quality zones. Excessive fluid loss to these high-quality thief zones results in a nonhomogenous distribution of stimulation fluids across the targeted interval. This leaves neighboring lower-quality zones unstimulated, preventing them from reaching their maximum potential. In this paper, a gel acid system composing hydrophobically modified PAM and viscoelastic surfactant (SA-16) as a novel self-diverting acidizing system was introduced, which can lower acid loss. This novel system was evaluated on temperature stability, viscosity test, gel breaken and acid-rock kinetics test supported by laboratory study. Its favorably high viscosity, ideal gel breaken, upstanding temperature resistance and other prior properties can be applied to acid stimulation.

Abstract: It presents the mechanisms of the bird’s legs, by exemplifying with the parrot. It gives structural data and they are written mathematical relationships which are necessary to write the calculations of these mechanisms. It shows how these mechanisms can be used as prehensile mechanisms, but also as stepping mechanisms. Such mechanisms can be used, for example, for the robots that are displaced on narrow bars.

Abstract: The precursor of LiNi_0.5 Mn_{Subscript text}1.5O₄ cathode material with high density was synthesized by two-dryness co-precipitation method. The optimized parameters were found out by studying the relationship between the density of precursor and the concentration of reactants, the manner of adding agglomerating agent, the remaining water in filter cake and the manner of dryness. The highest density (1.74 g/cm3) of precursor can be achieved under optimized condition: NiSO₄ 0.375 mol/L, coagulation agent added with little amount but many times, 28% of water in filter cake and two-step dryness, which is much better than that made by other methods. Our experiment provides a significant reference for the synthesis of excellent-performance cathode materials of lithium-ion battery. LiNi_0.5 Mn_{Subscript text}1.5O₄has a good cycle performance, a higher discharge capacity and a discharge platform of 4.7v, so it has become a research focus of 5-voltage cathode materials in the field of lithium ion battery recently.[1-4] However, LiNi0.5Mn1.5O4 prepared by common methods usually has a lower tap volume capacity.[5-9] HiroyuKi Ito[6] reported a continuous fabricated high-density cobalt-manganese-doped nickel hydroxide method with which the density of product was between 1.5-1.91g/cm3, however the used ammonia as a complexation agent in the preparation process not only increased the cost of the preparation, but also led to environmental pollution. Research results show that the cathode material synthesized using high-density precursor has a higher tap density, a larger volume capacity and a good electrochemical performance.[10] In this paper, we find out the optimized parameters of preparation of precursor of LiNi_0.5 Mn_{Subscript text}1.5O₄ by studying the relationship between the density of precursor and concentration of reactants, the manner of adding agglomerating agent, the remaining water in filter cake and the manner of dryness.