Active nanostructures which provide unique transformations are being introduced to phase matched porous silicon (PS) nano/micropores to form a platform for low power consumption highly selective sensors and microreactors. TiO2-xNx photocatalysts have been formed in seconds at room temperature at the nanoscale via the direct nitration of anatase TiO2 nanocolloids. Tunability throughout the visible depends upon the degree of agglomeration and the ability to seed these nanoparticles with metal ions. Co metal ion seeding leads to the efficient room temperature phase transformation, of anatase to rutile TiO2, where normally much higher temperatures are required. Seeding of a properly nitridated TiO2 nanocolloid with transition metal ions (Co, Ni) allows for the enhancement of the infrared spectra of the TiO2-xNx nitridated titania surface in excess of 10-fold, providing a means to analyze for minor contaminants and intermediates. Evidence for nitrogen fixation is found in Fe treated systems. The TiO2-xNx systems act as visible light absorbing photocatalyts. These photocatalysts and additional nanostructured metal oxides can be placed on the surface of PS-based sensor and microreactor configurations to greatly improve the interface response.

Linear rheological behavior and Microrheology measurements of sodium salt calf-thymus DNA aqueous solutions as a function of concentration are reported here. The microrheological behavior was obtained by a combination of experimental techniques: mechanical Rheometry and Dynamic light scattering (DLS). The viscoelastic properties of DNA in water as a function of concentration were performed at 20 °C and rheological and microrhelogical curves were performed. The result indicated that for concentrations lower than the entanglement concentration (Ce ) the system exhibits a predominantly viscous behavior, whereas for higher concentrations exhibits a predominantly elastic behavior. The plateau modulus (G0 ) and the zero complex viscosity () follow a power law concentration dependence of the form: and , respectively The microrheology results overlap perfectly in a single line with the mechanical rheology results, extending the time resolution to faster breathing modes

In this paper, we present CVD (Chemical Vapor Deposition) growth and passivation of tungsten (W) and titanium nitride (TiN) nanocrystals (NCs) on silicon dioxide and silicon nitride for use as charge trapping layer in floating gate memory devices. NCs are deposited in an 8 inches industrial CVD Centura tool. W and TiN are chosen for being compatible with MOSFET memory fabrication process. For protecting NCs from oxidation, a silicon shell is selectively deposited on them. Moreover, for a better passivation, TiN NCs are encapsulated in silicon nitride (Si3N4) in order to get rid of oxidation issues. After high temperature annealing (1050°C under N2 during 1 minute) XPS measurements point out that NCs are still metallic, which makes them good candidates for being used as charge trapping layer in floating gate memories.

We have proposed a new model for microcrack detection by osteocytes in bone. According to this model, cell signalling is initiated by the cutting of cellular processes which span the crack. We show that shear displacements of the crack faces are needed to rupture these processes, in an action similar to that of a pair of scissors. Current work involves a combination of cell biology experiments, theoretical and experimental fracture mechanics and system modelling using control theory approaches. The approach will be useful for understanding effects of extreme loading, aging, disease states and drug treatments on bone damage and repair; the present paper presents recent results from experiments and simulations as part of current, ongoing research.

A wide range of diamond pad conditioner (disk) designs have been characterized and key performance metrics have been collected. Relationships between design characteristics including diamond size and shape, spatial density, and tip height distribution and polishing pad wear rates and pad surface textures have been established for a variety of pads.

Estimation of the depth-of-penetration of working diamonds, from used disk analyses, allows meaningful topographic assessments of alternative conditioner designs and predictions of relative performance. An example of an improved conditioner that illustrates this design methodology is given.

Conditioner aggressiveness and its decay in various slurries have been measured to assess disk lifetime in Chemical Mechanical Planarization (CMP) processes environments. Key factors affecting disk lifetime are discussed and an improved-lifetime conditioner for use in aggressive slurries will be reviewed.

Waspaloy specimens aged at 800°C from 0.5h to 88.5h were evaluated via small angle neutron scattering (SANS), ultra small angle X-ray scattering (USAXS), electrical resistivity, and SEM. The average γ' precipitate size and volume fraction, obtained from modeling the small angle scattering data, was used to calculate a figure of merit of electron scattering. This figure of merit is designed to correlate the electron scattering ability of the material to the precipitate microstructure. The USAXS data shows a secondary precipitate population at smaller diameters that is absent from the SANS data, since the SANS measurements were not obtained at high enough values of Q. It is believed that this secondary population makes the USAXS-derived figure of merit more sensitive to the actual measured resistivity response than the SANS-derived values; however, the SANS derived primary precipitate sizes are believed to more accurate due to a larger sample volume.

Assessing the long-term behavior of nuclear glass implies the prediction of their long-term performance, and more precisely of their evolution under irradiation and during interaction with water. After briefly recalling the major characteristics of the local and medium-range structure of borosilicate glasses of nuclear interest, we will present some structural features observed under forcing conditions. Specific structural tools (EXAFS/XANES, Neutron/x-ray diffraction, solid state spectroscopic methods…) are correlated with numerical simulations to determine the local structure of glass and provide selective information on glass surface using total electron yield detection. During alteration in near- or under-saturated conditions, some elements such as Fe change coordination, as other elements such as Zr only suffer structural modifications in under-saturated conditions. These structural modifications may explain the chemical dependence of the initial alteration rate and the transition to the residual regime. They also illustrate the molecular-scale origin of the processes at the origin of the glass-to-gel transformation. Molecular scale processes help in predicting the properties of new generations of nuclear glasses required by future production of nuclear energy. Under irradiation, various structural effects are observed, including coordination change, ion migration or disorder effects. These studies show that glasses with a simplified composition do not show the same behavior as more realistic glasses. Molecular dynamics (MD) simulations provide complementary information on elastic effects. Recent direct evidence for B-coordination change under external irradiation together with structural models derived from MD sheds light on the structural mechanisms at the origin of radiation-induced modifications of glass properties, emphasizing the importance of the thermal regime in the cascade core.

The crystallization kinetics of nano-structured amorphous Ge2Sb2Te5 (GST) regions (20-100 nm in diameter) obtained by Electron Beam Lithography (EBL) and 40 KeV Ge+ 1014/cm2 ion irradiation of crystalline 20 nm thick films was investigated. The amorphous regions, surrounded by crystalline cubic (fcc) or hexagonal (hcp) phase, were recrystallized by isothermal annealing in the temperature range 80°C - 120°C and by focused electron beam irradiation. The process was followed in situ by transmission electron microscope (TEM). The recrystallization is governed by the growth of the surrounding f.c.c. crystalline interface with a velocity of 2×10-2 nm/s at 110°C. The interface velocity is higher in the h.c.p. substrate less than a factor ten. Local focused electron beam irradiation induces instead crystalline nucleation inside the nano amorphous regions. Similar experiments have been performed on planar ion amorphized thin films lying on both GST crystalline phases. In both cases the recrystallization is mainly associated to the movement of the amorphous-crystalline interface. These results indicate that the stability of the amorphous region, generated by ion irradiation, is severely affected by the adjacent crystalline structure and by the size of the amorphous area, critically involved in the scaling of the PCM-based devices.

In the last fifteen years, there have been significant changes in the production of medicines, mainly in the addition of new components to the formulation of solid dosage forms. The current trend of “back to nature” to lead to a healthier life has led those who are engaged in the pharmaceutical field to develop new formulations that allow the use of natural products of plant origin

For example, excipient ingredients, used as carriers for a drug's active ingredients, are now being used. These are incorporated into a drug in order to facilitate the drug's preparation, maintenance, or administration. The excipient is beneficial to the patient because it allows the drug to be easily administered and absorbed by the human body [3]

There is evidence that the clays have great potential for both absorption and adsorption due to its tiny particles. In addition, it has been reported that some clays have an effective antiseptic and healing ability [5–8]

In the present work, a clay called bentonite was tested as a support vehicle of an inflammatory agent derived from a Mexican native plant called Distictis buccinatoria, commonly named “Tonacaxóchitl”. Studies carried out by Rojas et al. have shown that the organic extract of this plant has important antibacterial, antifungal, cytotoxic and anti-inflammatory properties [9]

Zirconium is an abundant element in nuclear wastes. In this paper, we present structural and crystallization results for a simplified glass composition belonging to the SiO2-Al2O3-B2O3-Na2O-CaO-ZrO2-RE2O3 system (RE = Nd or La) developed to immobilize highly concentrated waste solutions. The effect of varying ZrO2 content on the structure and the crystallization tendency of this glass was studied using a multi-spectroscopic approach. Zr was shown to be located in six-fold coordinated sites whose charge compensation seems preferentially insured by Na+ cations. Whereas a significant decrease of the proportion of BO4 units was observed with ZrO2 content, no effect was detected on the environment of AlO4 units. However, a significant structural evolution of the silicate network occurred due to the formation of Si-O-Zr bonds. Whatever ZrO2 concentration, the crystallization of only a rare earth silicate apatite phase was observed during either slow cooling from the melt or isothermal heat treatment. Whereas nucleation mainly occurred from the surface of the glass without ZrO2, the introduction of zirconium induced apatite crystallization in the bulk. It is proposed that this nucleating effect of ZrO2 is mainly due to changes induced in the neighborhood of Nd3+ cations in glass structure.

The blocks of glassy material at 55 wt.% SB4 waste loading produced in a demountable cold crucible and cooled to room temperature in cold crucible and glasses cooled in a resistive furnace by a canister centerline cooling (CCC) regime were sectioned to investigate phase composition and elemental distribution between various parts of the blocks. X-ray diffraction (XRD), optical microscopy, scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) and infrared (IR) spectroscopy studies revealed some difference in the texture but not in phase composition of the materials sampled from various parts of the blocks. The glass samples were composed of vitreous and spinel structure phases. Spinel was present as both skeleton-type aggregates of fine (micron- or submicron-sized) crystals segregated at early stages of melt solidification and larger (up to tens of microns) individual more regular crystals formed during slow melt cooling. There was some tendency for elemental segregation in the glass block from the cold crucible with enrichment of the deeper zones with heavier transition metal ions and depletion of Na, Cs, Ca, Al and Si. Uranium was quite uniformly distributed within zones of the block and entered the vitreous phase.

We have fabricated sub-100 nm triangles NiFe triangle arrays using NSL and the MOKE measurement and micromagnetic simulations were carried out to investigate the reversal mechanism of the arrays. Enhancement of coercivity compared to the thin film was observed in all the three arrays but in different degree from the MOKE measurement. With the increase of the lateral size of the triangle, the effect of the coercivity enhancing decreases. Micromagnetic simulation shows that instead of domain wall nucleation and annihilation in the thin film, the reversal mechanism of the 45 and 80 nm triangles is dominated by the coherent rotation. While in the 100 nm triangle, the magnetic reversal takes place via forming and reversing a V like sate.

The photovoltaic market is currently dominated by multicrystalline silicon. However, this material is characterized by intrinsic structural heterogeneity due to point defects, dislocations and grain boundaries. In order to improve the cell performance the control of the electrical properties of the grain boundaries and dislocations is required. The laser beam induced current technique allows the estimation of the variations of the charge capture rates due to the different trapping centers, and is a powerful tool for the characterization of multicrystalline silicon solar cells. Nevertheless, one has to control the reflected light in order to obtain a reliable estimation of the electrical parameters.

Electronic textiles (or e-textiles) have a wide range of potential applications in wearable computing and large-area applications, including medical monitoring, assistance to the disabled, and distributed sensor networks. We aim to integrate thin-film electronics directly into clothing during the weaving process. First, thin-film devices are fabricated on plastic substrates. Individual devices are separated by cutting the substrate into stripes which can then be woven into a textile. Devices on stripes need to survive high applied bending strains during weaving. As a first building block, we used atomic layer deposition (ALD) at a maximum temperature of 150oC to fabricate bottom-gate zinc-oxide thin-film transistors (TFTs) with a 25nm-thick Al2O3 gate dielectric, and a 15nm-thick ZnO semiconducting layer on 50μm-thick Kapton E substrates. These TFTs had average mobilities of 12cm2/Vs, threshold voltages around 1V and subthreshold slopes around 250mV/decade. However, after applying a tensile bending diameter of 1cm to the TFTs, ~80% of TFTs fail due to cracking of the brittle device layers. We studied causes of failure and investigated patterning holes in the brittle layers to prevent crack propagation though the channel. This reduced TFT failure to ~45% under the same applied bending conditions. In this paper, we will discuss failure mechanisms in our standard TFT structure when high tensile bending strains are applied and how the device structure was adjusted to decrease TFT failure.

In this paper, we present a stretchable electrode array for studying cell behavior subjected to mechanical strain. The electrode array consists of four gold nail-head pins (250μm tip diameter and 1.75mm spacing) or tungsten microwires (25.4μm in diameter) inserted into a polydimethylsiloxane (PDMS) platform (25.4×25.4mm2).Fusible indium alloy (liquid at room temperature) filled microchannels were used to connect the electrodes to the outside, thus providing the required stretchability. The electrodes were able to withstand strains of up to 40%. Repeated strain tests of several hundred cycles did not reveal any failure, illustrating the robustness of the platform. Mice cardiomyocytes and chick neurons were successfully cultured onto the platform.

In this study, we investigated the growth of silicon nanowires forced by small gallium droplet templates. Those gallium islands previously were deposited by a modified PECVD method. Two different delivery techniques of the trimethylgallium precursor (TMGa) were tested regarding their applicability. On the one hand standard liquid delivery was performed, on the other the precursor was transported by vapor draw out of the heated bubbler. The TMGa then was pulsed into the carrier gas flow. The effects on the deposited islands of both delivery methods were compared. As substrates <111> oriented p-doped silicon wafers were used. For the subsequent growth of the silicon wires similarly PECVD was used as growth method. Silane served as precursor. Argon and hydrogen were used as plasma enhanced gases. The effects of the Ga particles deposited by both process modes upon the generated wires were analyzed.

The chemical regeneration method of human enamel was improved for the probable clinical application: an oral medical device was designed to significantly reduce the necessary amount of remineralization liquid; the reactive liquid phase system was redesigned, thus the solution could be stored for long time.

Carbon steel overpack will corrode by consuming oxygen introduced during repository construction after closure of repository, that will keep the environment in the vicinity of repository reducing. The iron corrosion products can migrate in bentonite as ferrous cations (Fe2+) through the interlayer of montmorillonite replacing the exchangeable sodium ions in the interlayer. This replacement of sodium may affect the migration behavior in the altered bentonite not only for redox-sensitive elements but also the other ions. Therefore we have carried out electrochemical analysis, of calcium, strontium or barium with the ferrous ion supplied by anodic corrosion of iron coupons in compacted bentonite. Fifteen micro liters of tracer solution containing 8.6 M of CaCl2 or 3.0 M of SrCl2 or 1.5 M BaCl2 were sspiked on the interface between the iron coupon and bentonite, for which the dry density was in the range of 1.4 to 1.5 Mg/m3, before assembling. The iron coupons were connected as working electrodes to the potentiostat and held at a constant supplied potential between - 500 to +300 mV (vs. Ag/AgCl reference electrode) for up to 7 days. Calcium and strontium could migrate faster and deeper into the bentonite than iron in each condition, while barium could migrate slower than iron. A model using dispersion and electromigration can explain the measured profiles in the bentonite specimens. The fitted value of electromigration velocity was a function of applied electrical potential and 10 to 23 nm/s for calcium, 11 to 19 for strontium, around 4 nm/s for barium and 5 to 15 nm/s for iron, respectively. Alternatively, the fitted value of the dispersion coefficient was not a function of applied potential, and the values were 3 - 8 × 10-12 m2/s for calcium, 2 - 4 × 10-12 m2/s for strontium, 5 - 10 × 10-12m2/s for barium and 3 - 9 × 10-12 m2/s for iron, respectively.

The grain size distribution allows characterizing quantitatively the microstructure at different stages of crystallization of an amorphous solid. We propose a generalization of the theory we established for spherical grains, to the case of grains with ellipsoidal shape. We discuss different anisotropic growth mechanisms of the grains in thin films. An analytical expression of the grain size distribution is obtained for the case where grains grow through a change of volume while keeping their shape invariant. The resulting normalized grain size distribution is shown to be affected by anisotropy through the time-decay of the effective growth rate.

Single-crystalline rock-salt PbS nanowires (NWs) were synthesized using three different routes; the solvothermal, chemical vapor transport, and gas-phase substitution reaction of pre-grown CdS NWs. They were uniformly grown with the [100] or [110], [112] direction in a controlled manner. In the solvothermal growth, the oriented attachment of the octylamine (OA) ligands enables the NWs to be produced with a controlled morphology and growth direction. As the concentration of OA increases, the growth direction evolves from the [100] to the higher surface-energy [110] and [112] directions. In the synthesis involving chemical vapor transport and the substitution reaction, the use of a lower growth temperature causes the higher surface-energy growth direction to change from [100] to [110]. We fabricated field effect transistors using single PbS NW, which showed intrinsic p-type semiconductor characteristics for all three routes. For the PbS NW with a thinner oxide layer, the carrier mobility was measured to be as high as 10 cm2V−1s−1.