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The small and medium Italian historical centres are characterized, among other things, by reconstruction that have occurred over the centuries after earthquakes. While earthquakes determine structural damages, human losses and loss of the functionality of an urban system above all, they may create, at the same time, new opportunities if the urban and socio-economical structures are improved during the reconstruction processes as a whole. These processes and the optimal implementation of planning models within them is not straightforward [1], due to that several issues emerge as a challenge of the reconstruction programmes (decision-making processes, general vision for the entire urban system for instance). According to the literature, although a unique definition has not still been coined, resilience can be defined as the capacity of a system (a city) to withstand and restore after a shocking episode (an earthquake). Mainly in the context of cities [2], some approaches have been framed and experimented by other authors [3, 4, 5]. Starting from a short literature review, focuses on theories and methodological approaches to evaluate urban resilience, this work analyses – through an interdisciplinary approach – the case study of Nocera Umbra twenty years after two devastating earthquakes occurred in 1997. The research represents a first attempt that aims at analysing if the implemented reconstruction strategies have made the urban system more resilient with respect to both the built and the socio-economic environment.

The Pervinca love charm is an inedited 15th century German text, preserved in clm. 7021, ff. 165v-166r. This article represents the first attempt to make its complete transcription from the manuscript, an interpretative translation into English and a description of its content. The Pervinca charm displays a perfectly coherent rhetorical structure enriched by Christian images of brightness and fire; the structure lays on a large set of older non-Christian motifs, like: “as the wax melts, let N. melt / neither eat nor drink / neither sleep nor be awake”, as well as on ancient rituals with silver, gold, salt and wax. The theological frame gives even more power to the Pervinca, whose (Latin) name is here the key device of its irresistible magical power. A part of this charm is based on ancient curses and maledictions meant as a punishment if the beloved tried to resist the love charm. The performer needs the efficacy of the Pervinca in order to gain emotional, physical and mental power over a woman.

This paper reports the fabrication process for capacitive micromachined ultrasonic transducers (cMUT) using surface micromachining techniques. We describe the processing steps that allow control with high repeatability of the transducer geometrical features (membrane radius, membrane thickness, vertical distance between electrodes) and of the mechanical properties of the structural materials (stress in the silicon nitride layer). The transducers are fabricated with the fixed electrode patterned on top of the silicon wafer, which works as a support for the device, thus reducing parasitic capacitances. Tests of cMUTs with 0.5-μm-thick silicon nitride membranes suspended on 0.4-μm-thick cavities were performed showing resonance frequency at 5.5 MHz

This paper addresses the simultaneous determination of the Young's modulus and the residual stress of thin silicon nitride films deposited by dual frequency plasma enhanced chemical vapour deposition, to be used in the fabrication of free-standing MEMS membranes. Load-deflection tests of circular membranes and measurements of the deformation of free-standing microbeams due to the internal-stress release were performed; parallely the microstructures were modelled by finite element analysis as a function of the Young's modulus and the internal stress. For each test structure a set of values of the Young's modulus and the internal stress was found and from their comparison the values for the deposited film can be determined.

We present an experimental study of x-ray absorption near edge structure (XANES) at L-2,L-3,L- M-2,M-3, and K edges of, respectively, Fe, Zr, and O in iron-doped zirconia (ZrO2: Fe) for different Fe dopant concentrations x (from x similar to 6% to x similar to 25% at.) and make the comparison with ab initio simulations at the OK-edge. The x-ray magnetic circular dichroism (XMCD) measurements show no evidence of ferromagnetic (FM) order for all the analyzed samples in agreement with our ab initio simulations, which show an antiferromagnetic (AFM) order. We found that substituting Zr with Fe atoms leads to a radical change in the O K-edge XANES spectrum, especially in the pre-edge region where a pre-edge peak appears. This pre-edge peak is ascribed to dipole transitions from O 1s to O 2p states that are hybridized with the unoccupied Fe 3d states. Both theoretical and experimental results reveal that the intensity of the pre-edge peak increases with Fe concentration, suggesting the increase of unoccupied Fe 3d states. The increase of Fe concentration increases oxygen vacancies as required for charge neutrality and consequently improves AFM ordering. According to our first-principles calculations, the effect of one Fe atom is mostly localized in the first oxygen shell and vanishes as one moves far from it. Thus the increase of the OK-pre-edge peak with increasing Fe concentration is due to the increase of percentage of oxygen atoms that are near neighbors to Fe atoms.

We systematically investigated, both theoretically and experimentally, Zr_(1-x) Fe_x O_(2-y) ranging from diluted (x ~ 0.05) up to large (x ~ 0.25) Fe concentration. By atomic layer deposition, we grew thin films of high-j zirconia in cubic phase with Fe uniformly distributed in the film, as proven by time of flight secondary ion mass spectrometry and transmission electron microscopy measurements. Iron is in Fe 3þ oxidation state suggesting the formation of oxygen vacancies with y concentration close to x/2. By ab-initio simulations, we studied the phase diagram relating the stability of monoclinic vs. tetragonal phase as a function of Fe doping and film thickness: the critical thickness at which the pure zirconia is stabilized in the tetragonal phase is estimated ranging from 2 to 6 nm according to film morphology. Preliminary results by X-ray magnetic circular dichroism and alternating gradient force magnetometry are discussed in comparison to ab initio data enlightening the role of oxygen vacancies in the magnetic properties of the system

In this paper, we describe the progress towards the fabrication of a tip on top of a glass fiber. This paper focuses exclusively on the patterning which is defined on top of the flat end of the fiber, covered by a thin layer of chromium film that has been previously deposited. A special electron resist is used to transfer the circular pattern on the fiber. The resist consists of octavynilsilsexquioxane which is evaporated on top of the fiber by sublimation. The use of a dry resist enables us to deposit a uniform layer on a very small area which is a very difficult task to obtain with the use of wet resists, which require spinning techniques, that should also be very difficult to use in the specific case of the end of an optical fiber. After development, the pattern is transferred to the chromium film underneath by wet etching. This procedure has been optimized in order to preserve the pattern resolution obtained by means of electron beam lithography. The chromium film is the mask which will be used to perform the etching of the fiber.

Piezoelectric crystals, ceramics, polymers, and piezocomposite materials have long dominated the ultrasonic transducer technology, especially in medical ultrasound imaging. In recent years, thanks to the advances in microfabrication techniques, the technology of capacitive Micromachined Ultrasonic Transducers (CMUTs) has emerged as a competitive technology in the field of medical imaging.

In this paper we report the design and the fabrication process for a 64-element capacitive micromachined ultrasonic transducer (cMUT) array, for application in medical imaging. The element size and separation between adjacent elements are chosen for operation at 7 MHz, a frequency typically used in tissue imaging. The fabrication process is based on surface micromachining techniques and is compatible with standard CMOS process, due to the materials used and the low-temperature deposition steps (PECVD silicon nitride for structural layer, evaporated chromium as sacrificial layer and sputtered aluminum for metallization). Electrical tests in air show typical resonance behaviour and no significant degradation during operation. Tests in water show wide bandwidth and pulse-echo operation.

Federal education policy is often described in the relatively narrow terms of education program legislation and regulations. The heart of the article is a set of case studies that illustrates and explains the U.S. Department of Education 's increasing reliance on a variety of approaches, in addition to legislation, to promote its education reform strategies. The case studies also demonstrate the department's trajectory toward a new policy-making model-one that combines a relatively small piece of legislation with a major public campaign significant both in its intended scope and level of involvement across all sectors. These case studies reveal a critical, albeit far less known, federal presence in education policy that may prove essential to forging greater common ground in education in the future.

We present the results of our project for the design, construction and on-sky tests of silicon grisms. Silicon grisms are optical devices, that provide a medium-high resolution spectroscopic mode in imaging instruments, without introducing major changes in instrument configuration. After some critical phases during the experimentation, a silicon grism has been eventually fabricated and inserted in the filter wheel of the Near Infrared camera NICS, at the focal plane of the National Galileo Telescope (TNG), the 3.5 m Italian facility at the Canary Islands (E). The results of the main phases of the grism fabrication and the results of the on-sky tests are detailed reported.

This installment of JLR's Critical Issues section is the final part of a three-part series on literacy and educational policy. We are especially pleased to publish the following responses, by three highly qualified policymakers, to the views expressed in Part 1 of this series (see Volume 28, Number 2). In Part 1, Judith Green with Carol Dixon, David Pearson, and Sharon Quint commented respectively on the ideas they believed to be crucial for policymakers to know about literacy from their perspectives as literacy researchers. At the same time, we published Donna Alvermann's reaction to the views of the three researchers, also from her perspective as a literacy researcher. As substantiated by their brief biographies at the beginning of this issue, Emerson J. Elliott, Gary K. Hart, and Marshall S. Smith are imminently qualified to write a response to the researchers' views from the perspective of those who are intimately involved with educational policy at the highest levels. We are especially gratified that these busy public officials consented to share their views in a forum of interest primarily to literacy researchers. We believe their willingness to do so bodes well for the future of a constructive dialogue between the literacy research and educational policy communities. Combined with Patrick Shannon's consideration of literacy and poverty in Part 2 of this series (see Volume 28, Number 3), we hope that this series has stimulated more attention about issues related to literacy research and educational policy. We encourage readers to ponder the perspectives and ideas presented in this series and to consider adding their own insights by submitting letters to the editor, which will be considered for future publication.

The United States faces great challenges externally, to be competitive in an economy that will be even more dominated by high-skill, knowledge-intensive jobs, and internally, by the need to maintain a strong democracy in an increasingly complex and diverse society. Essential to meeting these challenges of economic success and social unity is the literacy ability and problem-solving capacity of all of its citizens. The general belief that many Americans currently lack these indispensable skills is fueling concerns that, as a nation, we face a literacy crisis. Although we will not argue for any one way to resolve, or even define, the literacy problem, we do believe that whatever intervention taken must be guided by the twin goals of quality and equality. Raising the overall literacy standard in America must go hand-in-hand with aggressively tackling the persistent gap between the reading levels of different groups of children. Moreover, although the responsibility for improving literacy lies mainly with families, schools, and communities, state and federal policy and resources can play an important supporting role in enabling the nation and all children to meet our society's rising demands for literacy. In their articles, David Pearson (1996), Sharon Quint (1996), and Judith Green and Carol Dixon (1996) raise several provocative issues about literacy and the potential role of policy. In this article, we will address three of those issues the nature both of literacy and the literacy problem, in-school interventions that can enhance literacy levels, and the importance of out-of-school literacy interventions.

In this paper we present the fabrication process of capacitive micromachined ultrasonic transducers by means of surface micromachining techniques using silicon on insulator (SOI) substrates as starting material. The use of SOI substrates provides a structural layer, in which the free-standing membranes are fabricated, of crystal silicon with excellent mechanical properties, and a sacrificial layer of buried oxide that can be etched selectively with respect to silicon. The process we developed has allowed to obtain transducers with resonance frequency at 6 MHz in air.

The fabrication of capacitive ultrasonic transducers by means of surface micromachining techniques and a low-temperature process is presented. Investigation of main process steps is reported. The use of polyimide as sacrificial layer, possible as the process is at low temperature, guarantees precise control of active transducer cells, thanks to its etching selectivity against the structural materials employed, and to the lithographic definition of the sacrificial layer into islands before the deposition of the membrane layer (pre-patterning). Control of the mechanical properties of free-standing membranes has been gained with the optimization of silicon nitride deposition and following thermal annealing steps. Transducers have been characterized by electrical impedance analysis, and their behavior agrees with theoretical modeling.

As post-Si era for digital device is incipient, In0.53Ga0.47As is a good candidate among n-type active channels with high electron mobility but - unlike Si - it lacks a well-established technology for dielectric gating which may bear aggressive device scaling. Here we propose a viable route for the atomic layer deposition (ALD) of high-? dielectrics taking advantage from the well-known selfcleaning effect of the trimethylaluminum (TMA) precursor on the III-V compound surfaces. In this respect, the incorporation of Al2O3 cycles both as a pre-conditioning surface treatment and inside the ALD growth of a MO2 host matrix (M=Zr, Hf) is here investigated. Al:MO2/In0.53Ga0.47As heterojunctions have been scrutinized by in situ spectroscopic ellipsometry and ex situ chemical depth-profiling analysis which validate a good physical quality of the oxide and elucidate the effect of the pre-conditioning cycles at the interface level. The resulting MOS capacitors have been characterized by means of multifrequency capacitancevoltage measurements and conductance analysis therein yielding a permittivity of 19±1 both for Al:HfO2 and Al:ZrO2 and similar electrical quality of the interfaces. On the other hand, Al:HfO2 appears to be electrically more robust against leakage and endowed with a lower frequency dispersion in accumulation.

Ultrasonic transducers are generally based on the piezoelectric effect and they are used in a variety of applications (medicalimaging, NDE, ranging). Some of the main reasons for choosing an alternative technology, based on electrostatic effect, arelow impedance mismatch with air and in water, low energy density, high efficiency, low costs, good integration with controlelectronics.Capacitive ultrasonic transducer consists in a parallel plates capacitor (like a condenser microphone) with a fixed electrodeand a free one (membrane). A cMUT (capacitive Micromachined Ultrasonic Transducer) consists of an array of capacitiveultrasonic transducer with metallized membranes suspended on silicon bulk. The membrane thickness is 0.4 mm. Tests ofthese transducers (@ 2.5 MHz) fabricated in our laboratories are in progress.

A technique based on shifted resist pattern and anisotropic wet etching has been developed for fabrication af quantum wires on (100) silicon and silicon/germanium substrates. The Electron Beam Lithography exposure of the same pattern properly shifted is used to obtain a mask for the subsequent wet etching. This etching takes advantage on the strong rate dependency on plane orientation and allows V groove shaped thin wires formation.

High-quality buried optical-waveguides were fabricated by reverse-proton-exchange in periodically-poled stoichiometric lithium tantalate. Experimental results show excellent fiber-mode matching, losses below 0.3 dB/cm and almost non-critical conditions for a quasi-phase-matched second-harmonic generation process from telecom wavelengths. The interaction length of 2.5 cm is the highest so far reported for lithium tantalate waveguides.

Resistive switching characteristics of polycrystalline nickel oxide were studied for non volatile memory applications. NiO was deposited by atomic layer deposition and electron beam evaporation on silicon and various metal bottom electrodes. After an initial electroforming step, NiO based devices with Pt top electrode and Si, Pt, Ni, TiN or W bottom electrodes exihibit reproducible unipolar switching. The film physical properties as well as electrode combinations influence the programming voltages and resistance window. While Pt and Si electrodes give a reduced dispersion of programming voltages and currents, the largest resistance window (up to four order of magnitude) is obtained when W is used. Preliminary data on the switching properties of amorphous Nb2O5 and polycrystalline ZrO2 films are also discussed.

RF micromechanical switches are fabricated using dry releasing techniques. LTCC is used as substrate. Amorphous silicon, as an alternative sacrificial layer to silicon dioxide, has been used followed by dry plasma release. The silicon deposition has been optimized to obtain low mechanical stress and allowing thick sacrificial layer deposition. The use of amorphous silicon extends the flexibility of the design of the devices and of the packaging procedure.

Room-temperature cw second-harmonic generation from telecom wavelengths, with 30% W(-1) cm(-2) efficiency and second-harmonic power levels up to 41 mW, was achieved in buried waveguides fabricated by reverse-proton exchange in 1% MgO-doped stoichiometric lithium tantalate without any evidence of optical damage. The technology proves suitable for the realization of efficient nonlinear frequency converters and all-optical devices.

The interfacing of a on-chip microreactor with the external world is investigated from the microfluidic point of view. A solution for coupling of input and output capillaries perpendicular on the micro-reactor plane is presented. The micro-reactor consists of a planar array of 7 x 7 metallic electrodes covered by a borofloat® glass reservoir provided with openings for the input and output capillaries having an internal diameter in the range of 220 – 500 μm on a chip of 12 x 13 mm. The reservoir has a volume of 60 μl and was manufactured by means of wet etching using a lithographically patterned Au/Cr mask. The capillaries are vertically inserted in the reservoir’s openings and leaned by means of silicone rings with cylindrical and respectively conical shape, the larger of them being glued with a silicone based adhesive. The key process steps were: cutting the rings with appropriate shape, size and contact surface; aligning and gluing the fixed rings. A functional trail of the obtained microreactor has been performed in an electrochemical set-up that allowed a continuous flow of the analyte of 10 μl / min.

The silicate spin-on-glass (SOG) assisted low temperature bonding of different types of glasses on silicon and silicon compounds substrates is widely used in micromachining of analytical devices. Two silicate spin-on-glasses (SOG), potassium silicate KASIL 2130 and sodium silicate N/N CLEAR , both of them from PQ Inc., are used. Previous experiments have revealed the formation of clusters and voids in the cured glass layer, that diminishes the bonding quality. A quantitatively analysis of the bonding process in terms of work of adhesion and interfacial tensions enabled us to identify the hot points of the bonding process: the wettability of the surfaces to be bounded, the appropriate concentration of the soluble glass, the adhesion of the spin-on-glass on these surfaces in both liquid and solid state, the spun-on-glass curing process. To overcome these hot points appropriate technological steps are added to the bonding process : O 2 plasma and hot HNO 3 exposure of glass/silicon respectively silicon nitride surfaces, one minute delay of spinning after sog-deposition on the substrate, increasing up to 125°C the annealing temperature of the spun-on-glass. Smooth, uniform, reproducible glass layers, are obtained and the dependency of their thickness (ranging from 100 A to 5000 A) versus silicate concentration of the soluble glass is determined. In order to explain the clusters and voids formation, successively observations of the cured layer after the annealing treatment and after room temperature storage are performed, and show that room temperature storage of non-completely cured silicate layers leads to the formation of clusters. The effect of the concentration of the soluble silicates is qualitatively analysed, by means of optical microscopy, showing that silicate solutions having 2 -3% of wt. are suitable for bonding applications with best results when the obtained glass layer is thin enough.

The completion of the DNA sequence of several genomes, including the human one, has opened completely new scientific and technological frontiers. The huge amount of genetic information available requires the development of faster and cheaper analytical tools. This can be possible by miniaturising the analytical system itself and by the development of proper analytical procedures, involving fluidic processes. A precise genetic identifying technique is hybridization, that can be accomplished in an array format on very small bidimensional surfaces. In order to automate the fluidic process involved in the DNA hybridization, three micromachining techniques are approached by the authors team, for obtaining reservoirs with volumes ranging from 1nl to 2μl using different materials as polyimide, silicon and glass. Several configurations were proposed targeting a turbulence free fluid flow. A qualitatively fluid flow study was performed and the influence of the reservoir shape was revealed. One obtained device was tested in a Laser Induced Fluorescence detection set-up.

In order to obtain specific channels and reservoirs in glass for analytic systems, the structuring of borosilicate glass has been studied. We used wet etching in HF diluted solution for etching channels up to 150 μm depth. A mask obtained by successively wet etching of previously evaporated Au and Cr layers has been used. A thick SJR 5740 type resist has been spun-on in order to accomplish the optical transfer of the pattern. A normal underetching not larger than the depth, has been obtained when adding a small amount of nitric acid, and using an appropriate annealing process after metal deposition. Neither pinholes nor cracks have been noticed after getting an etching depth of 180 μm. Double side etching has been performed for penetrating the glass. The dependence of the etching rate vs. both HF and HNO 3 concentration is outlined together with the etched surface quality.