The combat fields of modern wars, including the struggle against global terrorism, are localized in diverse, harsh regions: tropical, desert, artic, marine, with varied weather conditions, which adversely affect the corrosion performance of the equipment and facilities involved.

For the sake of brevity, three groups of military mobile and fixed equipment and structures are dealt with: armored ground wheeled vehicles; naval aluminum vessels, and buildings and facilities for providing dwellings, weapons storage and services to the armed forces. They are usually made from carbon steel, aluminum alloys and reinforced concrete, because of their useful properties: high strength, easy availability and low cost. However, due to their limited corrosion resistance they should be protected by coatings (including military coatings), but primarily paint; cathodic protection and corrosion inhibitors.

All these systems suffer from several types of localized corrosion and degradation: galvanic, pitting, intergranular, dealloying, cavitation, erosion, stress cracking, UV effects in plastics and organic coatings. The military assets require the implementation of corrosion control methods and techniques through all their stages: design, construction, installation and operation. Typical cases of corrosion will be presented based on the authors experience and knowledge.

In this work, the effect of three principal and independent parameters of Atmospheric Plasma Spray on the properties of coatings deposited using mixtures of commercial powders of titanium dioxide (TiO2) and chromium oxide (Cr2O3) was studied. The results of this work are used for special applications on turbomachinery components such as wear protection in sliding seals and in steam valves for turbines, chemical protection for centrifugal compressor members, and special seal applications.

The design of experiments (DoE) technique has proved to be very useful to study the influence factors and optimization. Pierlot et al. [1] demonstrated that the application of the Hadamard and two factorial design techniques are useful for the optimization of thermal spray processes. An example of the application of the DoE is the one mentioned by Murugan et al. [2]. In their work, a factorial design was used to study the interactions between gas flow, oxygen flow, powder rate and spray distance on the percentage of porosity and hardness of TiO2 - Cr2O3 composite coatings generated by High Velocity Oxy-Fuel.

The ½ fractional two-level factorial DoE technique was used to analyze and optimize the Atmospheric Plasma Spray process parameters. In the current research, experiments were conducted varying the deposition velocity, gas flow and stand-off distance. The effect of these process variables were evaluated by thickness, hardness and microstructure analysis. In this study, an empirical relationship between process variables and response parameters was developed. The entire relationship was made using the results of the DoE.

This paper focus on evaluating the ability to use Mexican fly ash (FA) and copper slag (CS) to produce alkali cements (0% OPC) or hybrid cements (20% OPC + 80% fly ash). The alkali activators used were two: 8 M NaOH solution for alkali cements and NaCl with sodium silicate for hybrid cement (HYC). Results of mechanical testing and characterization of the reaction products formed after 2 and 28 days are presented and discussed. Mechanical strength in some cases exceeded 20 MPa, at 2 days curing. The chemical characterization techniques used were X-Ray Diffraction (XRD) and scanning electron microscopy (SEM).

One of the most important parts of a hybrid reactor is the cladding because it should withstand high temperatures, neutrons with high energy, high neutron flux, as well as provide the first security contention. Besides, the material should have good mechanical properties to remove the heat. Although, the cladding material choice will have a great influence on criticality calculations. In previous works on ADS there is no cladding used, therefore in this paper it is tested different cladding materials based on SS-316, ODS, T91 and 15-15Ti used in nuclear reactors, to study the variations on the fuel depletion and variations on the neutronic parameters. The results using the cladding are compared with the one obtained without using it. The best material choice is based on the neutronic parameters that presents the closest behavior to the ADS simulated without clad.

The synthesis of alloys with nominal composition for Y1-xSmxCo5 by means of arc furnace and melt-spinning, is of critical scientific importance due that if replaced partially or completely the Samarium by the Yttrium is possible understand what contribution the earth element rare to the exchange interactions that guide to increased remnant magnetization in a nanocomposite. The alloys of Y1-xSmxCo5/Co obtained by melt-spun were characterized by x-ray diffraction with a compact hexagonal crystal structure the CaCu5 type. The alloys for nanocomposites of Y1-xSmxCo5/Co ribbons show ferromagnetic behavior with good magnetic properties, order to demonstrate this the magnetic properties were measured using a pulsed field magnetometer applying a high magnetic field in order to obtain a saturated magnetization curve and a high coercivity of 0.69 MA/m and an enhanced remanence of σr/σsat ratio equal to 0.57 were determined.

The synthesis of Fe3O4-Ag bimetallic nanoparticles by chemical reduction was carried out. Fe nanoparticles were obtained using Fe (III) Chloride hexahydrate (FeCl3•6H2O) as precursor and sodium borohydride (NaBH4) as reducing agent, subsequently, a solution of silver nitrate (AgNO3) was added to the reaction. The synthesis methodology employed in this case, is a modification of chemical reduction method. Through this procedure has been possible simplify the synthesis route used to obtain bimetallic systems such as Fe3O4-Ag. Particles with semi-spherical morphology were observed. High-resolution transmission electron microscopy (HREM), ultraviolet visible spectroscopy (UV-is) and quasi-elastic light scattering (QELS) techniques were employed for the structural characterization of Fe3O4-Ag nanostructures. Some models presented describe and prove the formation of the Fe3O4-Ag alloy type structures.

The conventional magnetic recording approached the physical frontiers of the recording density. The magnetic recording must face the famous trilemma: In order to increase the recording density, smaller grain volumes are needed, but in order to ensure the thermal stability of recorded information, the anisotropy constant should be increased accordingly; what results is an increased anisotropy field, which requires higher writing fields. Such fields are unavailable with the maximum saturation magnetization obtainable with the magnetic materials of the current heads. In order to overcome these problems, new media structures have been proposed. The most promising is the bit-patterned magnetic media (BPM), intensively studied over the last years with the aim of obtaining obtain an ultra-high recording density of hard-disk drives. A BPM comprises monodisperse high-anisotropy nano-particles in a self-organized patterning. They have a higher thermal stability, a lower noise and a higher signal resolution, which leads to a higher recording density and a better SNR. They eliminate the transition noise and, due to the large fraction of the bit volume occupied by the magnetic dots, improve thermal stability. Nevertheless, some important issues such as long-range patterning, control of the surface roughness, signal readout, etc., remain critical problems to solve. Another challenge is the fact that recording on BPM is sensitive to the material and geometry parameter fluctuations that may lead to additional constraints and require tight synchronization of the write-field misregistration time and bit positions. A possible route to higher recording densities is to use a multilevel recording, where more than two states are stored per dot.

Lead halide perovskites have proven their great power conversion efficiency (PCE) in the last few years and attracted more and more attentions. Evaporation is an important method to get high quality perovskite films, especially for surface and interface investigation, which is important for the solar cell performance. In this paper, we present our investigations on growing PbI2 and CH3NH3I films by evaporation, and then CH3NH3PbI3 films by co-evaporation. X-ray photoemisson spectroscopy (XPS) was used to characterize the films. The results showed that CH3NH3I film was not stable in vacuum. Both N and I decreased in vacuum with time elapsing. PbI2 and CH3NH3PbI3 films are quite stable. The atomic ratio of CH3NH3PbI3 films (C: N: Pb: I =1.29:1.07:1.00:2.94) is very close to the ideal CH3NH3PbI3, which indicates that evaporation is a good method to get high quality perovskite films with accurate atomic ratio.

Polypeptides are receiving increasing attention as building blocks to create nanostructures for biomedical applications. The first goal of this investigation was to explore the influence of the reaction conditions in the synthesis of well-defined dendritic graft (arborescent) polypeptides from amine-terminated poly(γ-benzyl L-glutamate) (PBG) chains. The optimization was carried out in terms of the reaction temperature, solvent, reaction time, and mole ratio of reactants and coupling agents. Size exclusion chromatography served to evaluate the grafting reaction in terms of grafting yield (fraction of side chains coupled with the substrate) and coupling efficiency (fraction of coupling sites consumed on the substrate). The maximum grafting yield and coupling efficiency achieved were 67% and 74%, respectively. These arborescent PBG substrates were subsequently grafted with poly(ethylene oxide) segments forming a hydrophilic shell, to obtain water-dispersible unimolecular micelles useful as delivery vehicles for doxorubicin.

The possibilities of Ni as contact material in electronic applications has motivated the interest on the intermetallic phases of the Ni-Sb system, in relation to their use in lead free micro-soldering processes. In this work, a detailed theoretical study of the cohesive and thermodynamic properties of the compound Ni3Sb in the (cF16) Fm-3m structure is reported. To this aim, the Full Potential Linearized Augmented Plane Waves method, within the framework of the Density Functional Theory and both Generalized Gradient and Local Density approximations, has been applied. The structural parameters, cohesive and elastic properties of this compound and its constituent elements have been determined. In particular, the equilibrium structural properties are determined through the minimization of the energy, including the full relaxation of the internal degrees of freedom of the cell. It is shown that the calculated properties agree well with the available experimental data. Moreover, various contributions to the electronic density of sates are studied. On this basis, a discussion is presented of the bonding characteristics of this compound, in the framework of the current ideas about cohesion in p-d bonded intermetallics.

The characteristics of silicon films deposited by plasma depend strongly on the reactor parameters. In our experiments, the two-level factorial design was implemented. Pressure, silane and hydrogen flows were set at high and low values for the synthesis of silicon films. Results showed that the flows of silane and hydrogen played a key role, being the influence of pressure low. In particular, the samples at high level of hydrogen exhibited the lowest deposition rate and photosensitivity. On the other hand, the samples at low level of hydrogen showed crystalline regions and high deposition rate. For the lowest dilution ratio, nano/meso-structured silicon films were obtained, showing high photosensitivity and high roughness that increases the scattering of light. These characteristics of our films make them suitable to be used in photovoltaics.

Commercial aluminum alloys corresponding to Al-Cu-Si family are commonly used in casting and molding process because their high castability. The main characteristics of these alloys are the excellent weight/strength relation in conjunction with wear and corrosion resistance. Additionally, the mechanical properties of these alloys could be enhanced by heat treatment.

In Al A319 alloys, Cu and Mg are the main responsible to increase the mechanical properties after T6 heat treatment due to the precipitation of Al2Cu and Mg2Si and Al2CuMg phase [1]. Combined effects of Ni and Cu improve strength and hardness at relatively elevated temperature [2], Due to the low solubility of Ni in Al (0.04%), it has been reported the formation of FeAl9FeNi-type intermetallic, which is not totally dissolved with the typical solution treatments used in aluminum alloys [3]. Hayajneh et al., found that increasing amounts of intermetallic compounds Al3Ni, Al3(CuNi)2 and Al7Cu4Ni in Al-Cu alloy, the hardness increase [4].

The effect of Ni addition and solution treatment time on the microstructure and hardness of the Al A319 alloy are studied by Vickers microhardness (VHN), Rockwell B hardness (HRB), X Ray Diffraction (XRD), Optical Microscopy (OM), Scanning Electron Microscopy (SEM).