Metal borides (AlB2, MgB2, Mg0.5Al0.5B2, AlB12, SiB6 and MgAlB14) and boron carbide (B4C) reacted with Al were compared to B, Mg, Al, Mg-Al and Si as potential energetic fuel additives. Stoichiometric physical mixtures of powders corresponding to unreacted boride compounds (Al+2B, Mg+2B, Mg-Al+2B, Al+12B, Si+6B, Mg-Al+14B, and B4C+2Al) were also investigated in comparison to the compounds. Submicron boron was used, which resulted in very fine particle sizes for all materials studied. It was demonstrated that boride compounds were less sensitive to low-temperature oxidation in flowing air than physical mixtures or metallic fuels. Compounds with high mole fractions of boron were generally less sensitive, but their high temperature oxidation behavior showed no improvement over boron. Cylinder expansion testing of MgAlB14 exposed its poor performance in an energetic mixture. However, aluminum and magnesium diborides (AlB2, MgB2 and Mg0.5Al0.5B2) also had relatively low sensitivity and exhibited mechanisms to increase the rate of boron oxidation at high temperatures, showing promise as insensitive high-energy-density fuel additives. Detonation calorimetry of mixtures with AlB2 or Al+2B suggested that the AlB2 mixture released approximately 50% more heat per gram than Al +2B and underwent complete reaction. These results warrant further testing of the diboride compounds in energetic formulations. Due to the high cost of boron and acceptable performance of B4C-Al mixtures, B4C should also be investigated as a lower-cost alternative to boron.

Aluminum-doped zinc oxide (ZnO:Al) thin films were prepared on glass substrates by radio frequency (RF) magnetron sputtering from a ceramic mixed target ZnO:Al2O3 (1 wt.%) with a power of 250 W. Two series of samples were deposited at room temperature, the first one in pure Ar atmosphere, the second one in Ar/O2 gas mixture. Effects of post-deposition annealing treatments carried out from 400 °C to 500 °C under vacuum and in N2/H2 (5%) atmosphere have been investigated. The influence of these parameters was studied by a detailed microstructural analysis using X-Ray diffraction and Raman spectroscopy. For N2/H2 annealing process, the increase of charge carrier concentration limits the increase of the mobility while after vacuum annealing, an improvement of both electrical and optical properties was observed. The increase of the crystallinity and grain size for ZnO:Al films deposited in Ar/O2 gas mixture could explain their improvements. Resistivity was reduced down to 3.5×10-4 Ω.cm, for a mobility of 49 cm2/V.s with a vacuum annealing at 450 °C for ZnO:Al deposited in Ar/O2 gas mixture.

Neurodegenerative disease is primarily characterized by protein misfolding and the resultant protein aggregation. Presence of soluble oligomeric aggregates of proteins including various Aβ and α-syn aggregate species can be correlated to the onset and progression of many neurodegenerative diseases. The ability to detect protein misfolding requires the design of a diagnostics assay the will enable molecular level probing. The use of nanoporous ceramic templates enables size based immobilization of the target proteins and by leveraging the principle of “macromolecular crowding” protein association can be mapped with a high degree of resolution. By tailoring the surface functionalization within nanoporous ceramic templates, macromolecular immobilization can be selectively controlled, which in turn significantly enhances the perturbation to the electrical double layer/. The changes to the electrical double layer are measured with a high degree of sensitivity through impedance spectroscopy.

Pre symptomatic diagnosis and distinction between Alzheimer’s and Parkinson’s diseases can be achieved by the specific detection and quantification of levels of each of these different toxic protein species in cerebrospinal fluid (CSF). Detection using highly selective morphology specific reagents in conjunction with the ultrasensitive nanoporous electronic biosensor showed the presence of different protein morphologies in human CSF samples. Detection is primarily achieved by identifying the specific association of the protein with its receptor using electrochemical impedance spectroscopy. Furthermore, we show that these morphology specific reagents can readily classify between post-mortem CSF samples from AD, PD and cognitively normal sources. These studies suggest that detection of specific oligomeric aggregate species holds great promise as sensitive biomarkers for neurodegenerative disease.

Ceramic barriers avoid catalyst diffusion to produce better multiwall carbon nanotubes (CNT) on carbon fiber fabrics (CF). We developed a simple method to produce efficiently a silica layer from TEOS pyrolysis at similar conditions of CNT growth from camphor and ferrocene mixtures. This protective layer prevents iron diffusion and allows the vertical alignment of CNTs.

While the global market for photovoltaic (PV) modules continues to grow 30% - 40% annually, manufacturers are looking at advanced technologies and cell concepts in order to improve the cost performance and reliability. One of the challenges faced by the silicon (Si) PV manufacturers is the lack of efficient metal screen-printing technologies. While screen-printing is a long-established technology, THE traditional silver-based pastes have technical limits in terms of paste composition, drying and thermal-firing conditions, line-width, aspect ratio, contact resistance, etc. Such limits keep the industrial cell structure from being close to an ideal PV cell architecture. In an effort to develop alternate printable pastes electrically, electrically conductive adhesives are considered in this study to provide fine-line contacts and low thermal budget so that performance-driven solar cell designs can be reliably implemented in manufacturing. Mechanical properties of solar cell printed by conductive adhesives are experimentally investigated in this work and confirmed with the simulation results.

Different synthesis methods has been employed to produce nanoparticles, however, chemical reduction method offer a effective route to obtained sizes nanoparticles controlled and morphologies very well defined. Iron nanoparticles were synthesized by chemical reduction using sodium borohydride (SB) NaBH4, Fe (III) Chloride hexahydrate (FeCl3·6H2O) as starting metallic salt (MS) and Poly-vinyl pyrrolidone (PVP) as surfactant agent. The nanoparticles have been characterized by transmission electron microscopy (TEM) and UV-Vis spectroscopy.

Nanostructured carbons have been widely used for fabricating enzyme-modified electrodes due to their large specific surface area. However, because they are random aggregates of particular or tubular nanocarbons, the post-modification of enzymes to their intra-nanospace is generally hard to control. Here, we describe a free-standing film of carbon nanotube forest (CNTF) that can form a hybrid ensemble with enzymes through liquid-induced shrinkage. This provides in-situ regulation of itsintra-nanospace (inter CNT pitch) to the size of enzymes, and eventually serves as a highly active electrode. The CNTF ensemble with fructose dehydrogenase (FDH) showed the oxidation current density of 16 mA cm-2in stirred 200 mM fructose solution. The power density of a biofuel cell using the FDH-CNTF anode and the Laccase-CNTF cathode reached 1.8 mW cm-2(at 0.45 V) in the stirred oxygenic fructose solution, more than 80 % of which could be maintained after continuous operation for 24 h. Application of the free-standing, flexible character of the enzyme-CNTF ensemble electrodes is demonstrated via their use in the patch or wound form.

The cyanide is the main process for the extraction of gold from its ores. This process produces rich cyanide solutions containing gold and silver, and waste cyanide solutions with different metal compounds such as copper, zinc and iron. These elements or compounds can be extracted in the form of high-value compounds as nanoparticles. This work presents some result of the remove and recovery of metallic values from waste cyanide solutions to obtain novel metallic nanoparticles. These materials were obtaining by modified sol-gel method from an industrial cyanide waste solution previously treated by advanced oxidation. This work reports the characterization from the nanoparticles by DRX and SEM-EDX. The results indicate that multimetallic nanoparticles can be obtained from cyanidation effluents.

Bioactive glass is an attractive scaffold material for use in filling bone defects because of its widely recognized ability to support the growth of bone cells and to bond firmly with hard and soft tissue. Use of bioactive glasses in the form of porous three-dimensional scaffolds for bone repair applications has been receiving considerable interest in recent years. However, bioactive glass scaffolds have been limited to the repair of low-load bone defects because of their low strength. In the present work, porous and strong bioactive glass scaffolds with an oriented microstructure were prepared by unidirectional freezing of camphene-based suspensions, and evaluated for their ability to regenerate bone in a non-healing rat calvarial defect model. Scaffolds of 13-93 glass (53SiO2, 6Na2O, 12K2O, 5MgO, 20CaO, 4P2O5; wt%) with a porosity of 50% and columnar pores of diameter 50–150 μm showed a compressive strength of 47 ± 5 MPa and an elastic modulus of 11 ± 3 GPa. Total bone regeneration in the oriented scaffolds, 18% after implantation for 12 weeks to 24% after 24 weeks, was not significantly different from that in 13-93 scaffolds with a microstructure similar to that of dry human trabecular bone (control group). The results indicated that these oriented bioactive glass (13-93) scaffolds could potentially be used in the regeneration of loaded bone.

We have investigated characteristic ferroelectric and structural antiphase domain structures in single crystals of hexagonal RMnO3 (R=Y, Ho, Lu, and Yb) by obtaining various electron diffraction patterns, dark-filed images and high-resolution lattice images. In the ferroelectric phase of RMnO3 characteristic domain structures consisting of six ferroelectric and structural antiphase domains, which can be identified as the “cloverleaf” pattern, is found in the (110) plane, in addition to the (001) plane, and are inherent to the ferroelectric phase of hexagonal RMnO3. In domain configuration with the cloverleaf pattern in the (110) plane, the structural antiphase boundaries are inclined to be parallel to the [001] direction.

In a highly dispersed flotation pulp, ultrafine hydrophilic minerals can entrain into froth products even though they may be perfectly hydrophilic. Therefore, effective depression of the hydrophilic minerals in froth flotation relies not only on rendering the minerals hydrophilic, but also on proper particle size control. In this paper, it will be shown that several depressants in mineral flotation systems indeed not only make the minerals hydrophilic but also cause selective coagulation or flocculation of the hydrophilic minerals. As a result, both the genuine flotation and the hydraulic entrainment of the hydrophilic minerals are reduced. The aforementioned depressants and mineral flotation systems include: zinc sulfate in the depression of sphalerite while copper sulfide and lead sulfide are floated; starch in the depression of iron oxides and phosphates while quartz is floated; polyethylene oxide in the depression of quartz while sulfide minerals such as chalcopyrite is floated.

Therefore, in fine and ultrafine particle flotation, the flotation depressants should be able to not only make the to-be-depressed minerals hydrophilic, but also make them selectively aggregate.

The aim of this work was to develop a new Ag-doped bioactive material with antibacterial behavior, optimizing the properties of the new fabricated composite material in the system SiO2 58.6 -P2O5 7.2 -Al2O3 4.2 -CaO 24.9 -Na2O 2.1 -K2O 3 (wt%). Two systems with different concentrations in Ag2O (Ba with 2.1 and Bb with 4.2 wt%) were prepared by the sol-gel method and compared to the respective silver-free control composite (CONTROL). The microstructural characteristics of the developed compositions were characterized by different techniques as UV/VIS spectroscopy, X-ray diffraction analysis (XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS). The antibacterial properties of the Ag-doped glass-ceramics were tested against the bacterial colony Staphylococcus aureus (S. aureus) which is very characteristic oral bacteria and the material-cell interaction was monitored in a primary culture of Human Gingival Fibroblasts (HGFs). Our study shows the successful incorporation of the silver ions in the ceramic structure and the preparation of new Ag-doped composite materials with cell-proliferation-inductive, as well as antibacterial properties indicating their potential application dental tissue restoration strategies.

Solid state PbS Quantum Dots (QDs)/TiO2 Nanoparticles heterojunction solar cells were produced by depositing PbS QDs on a 500nm thick Mesoscopic TiO2 films using layer-by-layer deposition. The heterojunction solar cells show photovoltaic response from the visible to the near infra-red region. Importantly, the PbS QDs act here as photosensitizers and at the same time as hole conductors. The PbS QDs/TiO2 device produces a remarkable short circuit photocurrent (Jsc) of 16.3 mA/cm2, an open circuit photovoltage (Voc) of 0.54 V and a fill factor (FF) of 0.41, corresponding to a light to electric power conversion efficiency (η) of 4.04% under 0.9 sun intensity.

Iodine filters expended after nuclear fuel reprocessing contain radioactive iodine (I-129), almost all of which exists as silver iodide (AgI). The synthetic rock technique is a solidification treatment technique using hot isostatic press (HIP), in which the alumina adsorbent base material is synthesized to form a dense solidified material (synthetic rock), and I-129 is physically confined in the form of AgI in the alumina matrix. Thus, it is necessary to understand the matrix dissolution behavior to evaluate the iodine release behavior.

Experiments involving the dissolution of the matrix were carried out under various temperatures (35–70 °C) and pH values (10–12.5) that reflect the disposal conditions. The results of the experiments showed that the dissolution rate of Al visibly increases with temperature and pH. The dissolution rate constant was calculated from the initial data assuming the dissolution of the matrix as a primary reaction. The logarithmic rate constant showed a good linear correlation with the pH and the reciprocal of temperature. The 27Al-NMR analysis of the solutions of the dissolved matrix showed that the major chemical species present in the solutions was Al(OH)4 -. This indicated that the dissolution of the matrix can be described by the following equation: Al2O3 + 2OH- + 3H2O → 2Al(OH)4 -. Subsequently, the empirical equation of the rate of dissolution of the matrix as a function of the temperature and pH was derived. It will be used to evaluate the iodine release behavior from the synthetic rock.

An identification of the characteristics of microbbubles dispersion is presented in this paper, when frother addition (MIBC) is modified in a biphasic system (air-water). Sauter diameter (d32), gas flow rate (Jg), superficial area flow density of the microbubbles (Sb) and air holdup (εg) are the measured variables in this research work. The studied frother additions were 0, 10 and 20 ppm. Similar to conventional bubble sizes, it was observed also, that air holdup increases with the air flow rate. The linear relationship between εg and Sb permits to conclude that superficial area flow density, a variable difficult to measure directly, may be estimated if air gas holdup is known. Furthermore, the experimental results showed that frother addition (MIBC) reduced the Sauter diameter, increasing all other variables.

The objective of the present work is to evaluate the Penicillium candidum filamentous fungi biocorrosion effects on AISI 4340 steel. Small AISI 4340 steel blocks are exposed to a biocorrosion process inside glass tubes containing culture media (Sabouraud Dextrose HIMEDIA broth) inoculated with Penicillium candidum spores for 14 days, at 25ºC constant temperature. The surface microstructures are evaluated by scanning electron microscopy, atomic force microscopy, and the chemical composition by energy dispersive X-ray spectroscopy. Comparison of micrographies before and after biocorrosion shows that surface structures present morphological alterations, suggesting corrosion wear. Grain contours can no longer be visualized and oxygen content on the steel surface increases to 32% after biocorrosion. Besides, topographic parameters like root mean square roughness (Rms), arithmetic mean roughness (Ra) and mean roughness (Rz) increase 57%, 132%, and 71%, respectively, from their initial values. It is concluded that AISI 4340 steel is reasonably susceptible to corrosion.

Nitridation is the process in which, during the initial growth of a-SiNx:H layers on Si surfaces, nitrogen (N) is incorporated into Si lattice near its surface. We show that this nitridation process affects the density of interface states (Dit ) and fixed charges (Qf ) at the interface. These parameters determine the effective surface passivation quality of the layers. The nitridation can be tuned independently of the growth of a-SiNx:H layers by using a plasma treatment prior to actual a-SiNx:H layer deposition. It is shown that the Qf can be varied from 2·1012 to 15·1012 cm-2 without changing the a-SiNx:H deposition process. It is demonstrated that in our case and processing window, Qf is the determining factor in surface passivation quality in the range of 2·1012 to 8·1012 cm-2. For higher values of Qf , Dit has increased significantly and has become dominant thereby reducing the passivation quality. It is shown that the passivation can be controlled independently of the a-SiNx:H deposition process. On completed solar cells this variation in Qf due to nitridation results in a change in open-circuit voltage, Voc, of almost 20mV.

3C-SiC is very attractive due the chance to be grown on large-area, low-cost Si substrates. Moreover, 3C-SiC has higher channel electron mobility with respect to 4H-SiC, interesting property in MOSFET applications. Other application fields where 3C-SiC can play a significant role are solar cells and MEMS-based sensors. In this work, we present a general overview of 3C-SiC growth on Si substrate. The influence of growth parameters, such as the growth rate, on the crystal quality of 3C-SiC films is discussed. The main issue for 3C-SiC development is the reduction of the stacking fault density, which shows an exponential decreasing trend with the film thickness tending to a saturation value of about 1000 cm-1. Some aspect of processing will be also faced with the realization of cantilever for Young modulus calculations and the implantation of Al ions for the study of damaging and recovery of the 3C-SiC crystal.

1,8-Diazabicyclo[5,4,0]undec-7-ene (DBU) was neutralized by a range of Brønsted acids with a wide variation in the ΔpK a values of their constituent acids and base. The salts exhibited properties characteristic of an ionic liquid, such as high thermal stability and liquidity near ambient temperature. Analyses of thermal behaviors and temperature dependencies of density, viscosity (η), and ionic conductivity were made to correlate the physicochemical properties with the ΔpK a value of the obtained protic ionic liquids (PILs). Differential thermal analyses (DTA) revealed that PILs with high ΔpK a values underwent thermal decomposition resembling their aprotic counterparts; however, PILs with a low ΔpK a exhibited the evaporation of neutral species progressively generated from the shifting of the equilibrium toward neutral components during the weight loss process. The ionicity of the PILs, determined from Walden plots utilizing density, conductivity, and viscosity data, was found to decrease as temperature increased, and this effect was more pronounced for low ΔpK a values, possibly because of the shifting of the equilibrium and the imbalance between strong hydrogen bonds and Coulombic interactions. Fragility, estimated from plots of log(η) versus the scaled temperature T g/T was found to be lower for PILs than for DBU owing to neutralization. [DBU]-based PILs exhibit intermediate fragility in nature, but this fragility becomes more prominent for PILs with low ΔpK a values

Herein, we investigated the effects of polyaniline (PANI) and polypyrrole (PPY) in their native and co-assembled forms as a thin layer on Pt nanoparticle-decorated multi-walled carbon nanotubes (Pt/MWCNTs) toward the ethanol oxidation reaction (EOR). The co-assembled conducting PANI-PPY deposited Pt/MWCNTs was successfully synthesized and demonstrated significant enhancement of the electro-catalytic activity and stability toward EOR as revealed by electrochemical characterizations. The presented results indicate that in the co-assembled form, PANI and PPY retained their own superior effects on the enhancement of stability and catalytic activity via intermediate species removal and ethanol adsorption, respectively. This preliminary result reveals a new strategy for the use of conducting polymers as potential catalyst supports due to its facile fabrication and functionalization, cost effectiveness and environmental friendliness in comparison to alloys and metal oxides, factors which are necessary for the practical application of direct ethanol fuel cells in the near future.