In 2010, Mexico celebrates 200 years since the beginning of the Independence war that gave rise to the independent Mexican Empire in 1821, and afterwards to the Mexican Republic. This document had two original copies; one of them was lost in a fire at the beginning of twentieth century, while the second was stolen and finally returned to Mexico in 1960, after a long history of events. This document is kept in the General Archives of Nation (AGN), Mexico.

The “Independence Act of the Mexican Empire of 1821” was written on paper using iron-gall inks. The document has two parts: a declaration and a set of 36 signatures of Iturbide and other people involved in establishing the Independence of Mexico.

The non-destructive study of this document was carried out in order to answer several questions: legitimacy, composition of the materials (paper and inks), deterioration conditions and a possible sequence of writing and the signatures. For these purposes several in situ techniques were used: optical microscopy, ultraviolet and infrared light imaging, portable X-ray Fluorescence and Raman Spectroscopy. This work presents the main results of this analytical methodology applied to the Mexican Independence Act. The results indicate that several inks were used in the manuscript and that the paper has an aging consistent with a nineteenth century document. From these results, we consider that the document examined is genuine and not a copy or facsimile of the original act.

This study was aimed to investigate in vitro and in vivo behavior of a Ti6Al7Nb biomaterial with a nanostructured HA-type coating and also the design and realization of a new special knee implant together with a selection of a suitable animal model for preclinical experimentation of the implants.

The metallic material used like substrate alloy for layer deposition was a Ti6Al7Nb alloy obtained by double electron beam melting furnace. In order to obtain a nano-crystalline HA-coating first sodium titanate layer was obtained on the surface and then the implant was immersed in Ringer solution with additional PAW1 biovitroceramic (particles under 20 μm). Different deposition times (5, 10 and 19 days) were employed. Microscopy analysis and corrosion tests of the implants relieves that the nanostructured HA layer after 19 days of immersion shows promising results as regarding the implant employ in preclinical experiments.

After a complex design based on knee bone radiography there has been manufactured two different types of devices for the metallic implants: a metallic plate and a pin. Two plates and two pins were implanted in each animal.

For in vivo experiments the chosen animal model was the mini-pig because of its strong chirurgical resistance and perfect anesthesia toleration. For the testing 10 animals were used for implantation and one for the control. When the plate is implanted the bone has to have a good blood supply after the cut in order to avoid bone to die. All experimented implants were maintained in the animal during six months and periodically inspected. No sign of infection or another problem were observed during this period.

In this contribution we present the results of Density-Functional Theory (DFT) calculations of platelets as modelled by infinite planar arrangements of hydrogen atoms and vacancies in (100) planes of silicon. From the observation of the relaxed platelet structures and the comparison of their energy with the one of hydrogen molecules dissolved in silicon we were able to evidence several features. A planar arrangement of hydrogen atoms inserted in the middle of Si-Si bonds proves unstable and Si bonds must be broken for the platelet to be stable. In the (100) plane the most stable configuration is the one with two Si-H bonds (a so-called SiH2 structure). It is possible to generate SiH3 structures which are more stable than hydrogen dissolved in Si bulk but less than SiH2 structures but SiH1 or SiH4 sometimes observed in experiments prove unstable.

Copper micro-crystal fracture mechanisms were discussed with the machining precisions under the several cutting conditions, such as cutting speed, cutting depth and width of grove formation by the diamond single crystal cutting tool which the scoop face of (100) crystal face. For the cutting test, the copper single at the size of 10 mm in diameter and 5 mm in height as the test piece which cut by single crystal diamond cutting tool with silicon oil on the shaper type ultra-precision cutting machine. Before groves cutting, the specimen surface was cut as flat by cutting-off tool (corner diameter; 50 mm, cutting width; 3.0 mm, scooping angle; 0 degree, and escape angle; 7.0 degree) at the work speed as 4000 mm/min and cutting depth of 5 μm. For the V-shape grove cutting, the flat copper surface was cut with the diamond-point cutting tool (V angle = 90 degree, scooping angle = 0 degree, and escape angle = 7.0 degree) at the work speed as 4-4000 m m/min and cutting depth of 0.1-10 μm for finishing machining. The cut machined surface was observed by optical microscope comparing the grove shapes. The diamond-point tool was also observed by optical microscope. As results of the cutting test of copper single crystal, the machining precision was better for the crystallographic direction of than the direction of under the deeper cutting profiles. The mechanisms of this fracture results considered that the slip plane of (111). On the other hand, shallow grove under 1.0 μm was better tracks scratched for the crystallographic direction of than the direction of . This result was also considered that the slip plane related to the fracture behavior. For copper crystal cutting in nanometric scale, the crystallographic direction was quite important.

During a two-step sintering practice, important factors such as final grain sizes and residual pore status can be controlled through adjusting the first and second step sintering temperatures and durations. Moreover, the sintering temperatures (both the first and the second step) can be several hundred degrees lower than those in a traditional sintering process to obtain fully dense ceramics. Therefore, it is a potentially cost-effective preparation procedure for ceramics with fine grains. In this work, we successfully demonstrated the synthesis of aggregate-free sesquioxide nanometer-sized powders with a narrow size distribution through a modified chemical co-precipitation process. Subsequently, ytterbium-doped Lu2O3 ceramics of near full density were obtained through a two-step sintering process.

Many systems, including peptide systems, have been identified thatself-assemble into nanometer sized structures. However, continuedself-assembly to the macroscopic scale has remained elusive even thoughnature routinely does it. Here, a unique hierarchical peptide self-assemblyprocess is described from the nanometer to the micrometer scale.

A microstructure-based FEM model that couples crystal plasticity, crystallographic descriptions of the B2-B19′ martensitic phase transformation, and anisotropic elasticity is used to simulate thermal cycling and isothermal deformation in polycrystalline NiTi (49.9at% Ni). The model inputs include anisotropic elastic properties, polycrystalline texture, DSC data, and a subset of isothermal deformation and load-biased thermal cycling data. A key experimental trend is captured—namely, the transformation strain during thermal cycling is predicted to reach a peak with increasing bias stress, due to the onset of plasticity at larger bias stress. Plasticity induces internal stress that affects both thermal cycling and isothermal deformation responses. Affected thermal cycling features include hysteretic width, two-way shape memory effect, and evolution of texture with increasing bias stress. Affected isothermal deformation features include increased hardening during loading and retained martensite after unloading. These trends are not captured by microstructural models that lack plasticity, nor are they all captured in a robust manner by phenomenological approaches. Despite this advance in microstructural modeling, quantitative differences exist, such as underprediction of open loop strain during thermal cycling.

In this article, we present a study of boron-doped hydrogenated nanocrystalline silicon (nc-Si: H) films by very high frequency-plasma enhanced chemical vapor deposition (VHF-PECVD) using high deposition pressure. Electrical, structural and optical properties of the films were investigated. Dark conductivity as high as 2.75S/cm of p-type nc-Si: H prepared at 2.5Torr pressure has been achieved at a deposition rate of 1.75Å/s for 25nm thin film. By controlling boron and phosphorus contamination, single junction nc-Si: H solar cells incorporated p-layers prepared under high pressure and low pressure, respectively, were deposited. It has been proven that nanocrystalline silicon solar cells with incorporation of p layer prepared at high pressure has resulted in enhanced open circuit voltage, short circuit current density and subsequently high conversion efficiency. Through the optimization of the bottom solar cell and application of ZnO/Al back reflector, 10.59% initial conversion efficiency of micromorph tandem solar cell (1.027cm2) with an open circuit voltage of 1.3864V, has been fabricated, where the bottom solar cell using a high pressure p layer was deposited in a single chamber.

We investigate the structural, optical and electrical properties of single-layer graphene exposed to oxygen plasma treatment. We find that the pristine semimetallic behavior of graphene disappears upon plasma treatment, in favour of the opening of a bandgap and the featuring of semiconducting properties. The metal-to-semiconductor transition observed appears to be dependent on the plasma treatment time. The semiconducting behavior is also confirmed by photoluminescence measurements. The opening of a bandgap in graphene is explained in terms of graphene surface functionalization with oxygen atoms, bonded as epoxy groups. Ab initio calculations of the density of states show more details about the oxygen–graphene interaction and its effects on the graphene optoelectronic properties, predicting no states near the Fermi level at increasing epoxy group density. The structural changes are also monitored by Raman spectroscopy, showing the progressive evolution of the sp2 character of pristine graphene to sp3, due to the lattice decoration with out-of-plane epoxy groups.

We have propsed MgO/AZO bi-layer transparent conducting oxide (TCO) for thin film solar cells. From XRD analysis, it was observed that the full width at half maximum of AZO decreased when it was grown on MgO precursor. The Hall mobility of MgO/AZO bi-layer was 17.5cm2/Vs, whereas that of AZO was 20.8cm2/Vs. These indicated that the crystallinity of AZO decreased by employing MgO precursor. However, the haze (=total diffusive transmittance/total transmittance) characteristics of highly crystalline AZO was significantly improved by MgO precursor. The average haze in the visible region increased from 14.3 to 48.2%, and that in the NIR region increased from 6.3 to 18.9%. The reflectance of microcrystalline silicon solar cell was decreased and external quantum efficiency was significantly improved by applying MgO/AZO bi-layer TCO. The efficiency of microcrystalline silicon solar cell with MgO/AZO bi-layer front TCO was 6.66%, whereas the efficiency of one with AZO single TCO was 5.19%.

Amorphous and microcrystalline silicon are currently used for electronic devices such as solar cells and thin-film transistors. This paper shows that silicon nanoparticle dispersion has the potential to be used as source material for polycrystalline silicon thin-film thus opening a route to solution processed silicon devices. After deposition, a classical thermal or microwave annealing step is used to induce the coalescence of the silicon nanoparticles. Both sintering techniques are studied in terms of morphology, electrical and optical properties.

The reported work focuses on developing antidiffusion barriers capable to increase the thermal stability of metal contacts above 700 C. In the chosen approach, such an antidiffusion barrier consists of several bilayers of materials with different crystalline structures. It has been demonstrated that an interface between such materials effectively blocks the atomic interdiffusion. In this work the following groups of materials were used as the bilayers: ZrB2 and ZrN and TaSiN and TiN. The materials were deposited by means of room temperature sputtering from elemental and compound targets in inert Ar and reactive Ar+N2 atmospheres. The structures were characterised using secondary ion mass spectroscopy depth profiling and scanning electron microscopy cross sectional imaging directly after deposition and after degradation. I-V characteristics were measured and contact resistivities were determined from the circular transmission line method.

Atomic force microscopy (AFM) allows for high-resolution topography studiesof biological cells, measurement of their mechanical properties, andquantification of protein-protein interactions in physiological conditions.In this work, AFM was employed to investigate morphological, material, andchemomechanical properties of red blood cells from human subjects withsickle cell trait. We measured the stiffness of the cells and demonstratedthat the Young’s modulus of pathological erythrocytes was three timesgreater than in normal cells. A single molecule AFM method was employed toreport that erythrocytes from human subjects with the sickle cell traitexpress a greater number of the laminin receptors BCAM/Lu (p < 0.05) thanerythrocytes from normal human subjects. Observed differences indicate theeffect of sickle hemoglobin in the erythrocyte and possible changes in theorganization of the cell cytoskeleton and membrane proteins associated withthe sickle cell trait.

Carbon nanofibers were used as building blocks for two-dimensional photonic crystal slabs. Electron beam lithography and chemical vapor deposition were used to fabricate regular arrays and random patterns of nanofibers. The optical properties of the samples were investigated using a diffraction measurement setup, as well as reflection ellipsometry. We find that carbon nanofiber regularity has a strong effect on both diffractive and specular optical properties. This shows that ellipsometry can be a valuable tool to study properties of carbon nanofiber arrays. It also shows that carbon nanofibers provide an interesting candidate as building blocks for nanostructured optical components.

Laser welding of transparent high performance polymer foils requires an additional absorption layer at the interface of both foils. This paper demonstrates that metallic nano-particles, e.g. gold, silver or copper, can act as such an absorption layer. Silver nanoparticles were deposited on the surface of 200 μm thick ethylene tetrafluoroethylene (ETFE) polymer foils by evaporation processes or by magnetron sputtering. For their additional mechanical stabilization, thin films produced by plasma polymerisation of hexamethyldisilazane or PTFE-polymer sputtering were deposited on top of the metal nanoparticles. Laser irradiation of the coated foil together with the untreated joining partner was performed by a continuous wave diode laser at a wavelength of 808 nm. With the defocused laser, the foils were welded and finally a nearly transparent welding seam was achieved. The nanostructure and the optical properties of the nanoparticle layer before laser irradiation were determined and compared with the nanostructure and the optical properties of the polymer metal nanocomposite after laser welding.

A monolithic double pi’n/pin a-SiC:H device that combines the demultiplexing operation with the simultaneous photodetection and self amplification of the signal is analyzed under different electrical and optical bias conditions at low and high excitation frequencies. Results show that the transducer is a bias wavelength current-controlled device that make use of changes in the wavelength of the background to control the power delivered to the load. Self optical bias amplification or quenching under uniform irradiation and transient conditions is achieved. The device acts as an optical amplifier whose gain depends on the background wavelength and frequency. An optoelectronic model supported by an electrical simulation explains the operation of the optical system.

We have previously described a numerical model for carrier diffusion and nonlinear quenching in the track of an electron in a scintillator. Significant inequality of electron and hole mobilities predicts a characteristic “hump” in the light yield vs gamma energy, whereas low mobility of either or both carriers accentuates the universal roll-off due to nonlinear quenching at low gamma energy (high dE/dx). The material parameter basis of the two major trends in nonproportionality of scintillators can be related to the effective diffusion coefficient of excitations and the difference of electron and hole mobilities, respectively. Activator concentration, type of activator, and effect of transport anisotropy are associated with minor trends. The predicted trends are qualitatively consistent with empirical measures of nonproportionality including electron yield curves.

A low temperature amorphous zinc indium oxide (ZIO) thin film transistor (TFT) backplane technology for high information content flexible organic light emitting diode (OLED) displays has been developed. We have fabricated 4.1-in. diagonal OLED backplanes on the Flexible Display Center’s six-inch wafer-scale pilot line using ZIO as the active layer. The ZIO based TFTs exhibited an effective saturation mobility of 18.6 cm2/V-s and a threshold voltage shift of 2.2 Volts or less under positive and negative gate bias DC stress for 10000 seconds. We report on the critical steps in the evolution of the backplane process: the qualification of the low temperature (200°C) ZIO process, the stability of the devices under forward and reverse bias stress, the transfer of the process to flexible plastic substrates, and the fabrication of white organic light emitting diode (OLED) displays.

We report on a strong effect of p-GaN surface morphology on the growth mode and surface roughness of ZnO:Ga films grown by plasma-assisted molecular-beam epitaxy on p-GaN/c-sapphire templates. A range of ZnO:Ga surface morphologies varying from rough surfaces with well defined three-dimensional islands, capable to enhance light extraction in light-emitting diodes, to rather smooth surfaces with a surface roughness of ~ 2 nm suitable for vertical-cavity lasers can be achieved by controlling the surface morphologies of p-GaN. Optical transmittance measurements revealed high transparency exceeding 90% in the visible spectral range for ZnO:Ga with both types of surface morphology.

Optimum processing conditions for fabricating SnO2 thin films were investigated to detect low ppm levels of ethylene gas for future on-field gas sensor applications. Different argon-to-oxygen ratios during R.F. sputtering were attempted to find the optimum gas ratio in depositing SnO2 thin film. Post-annealing was performed at 650°C to investigate the influence of film property change on ethylene sensing property of sensor. As-deposited and post-annealed films prepared under four different argon-to-oxygen ratios were studied by SEM, XRD, and sensitivity measurement. It was found that the stoichiometry and crystallinity of SnO2 films determined by post annealing was more influential than those by the argon to oxygen ratio during R.F sputtering on ethylene gas detection. An ethylene gas-sensing mechanism on R.F. sputtered SnO2 thin films for the design of processing conditions is proposed.