247 research outputs found
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Direct-Write Fabrication of Integrated, Multilayer Ceramic Components
The need for advanced (electronic) ceramic components with smaller size, greater
functionality, and enhanced reliability requires the ability to integrate electronic ceramics in
complex 3-D architectures. For rapid prototyping and small-lot manufacturing, traditional tape
casting and screen printing approaches are poorly suited. To address this need, we are developing
a direct-write approach for fabricating highly integrated, multilayer components using a
micropen to deposit slurries in precise patterns. With this technique, components can be
constructed layer by layer, simplifying fabrication. It can also be used to produce structures
combining several materials in a single layer. The parts are either cofired or sequentially fired,
after each layer is deposited. Since differential shrinkage can lead to defects in these multilayer
structures, we are characterizing the sintering behavior ofindividua1layers. This technique has
been used to fabricate devices such integrated RC filters, multilayer voltage transformers, and
other passive components. The direct-write approach provides the ability to fabricate
multifunctional, multimaterial integrated ceramic components (MMICCs) in an agile and rapid
way.Mechanical Engineerin
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Development and integration of applique decoupling capacitors
For high-speed integrated circuit applications, it is important to interconnect decoupling capacitors and integrated circuits (ICs) as intimately as possible, to minimize parasitic impedances. This can be achieved by mounting free-standing, thin film capacitors directly onto ICs as part of a chip-scale packaging approach. These applique capacitors utilize a chemically-prepared PLZT dielectric, which is nominally 1 {micro}m thick. The small size and weight of applique capacitors can be used to improve packaging efficiency. Applique capacitors, which are initially fabricated on silicon wafers, have high permittivity ({var_epsilon} {approx_equal} 1,000), low loss (tan{delta} {approx_equal} 0.01) and high breakdown strength (E{sub b} {approx_equal} 1 MV/cm) and leakage resistance ({rho} > 10{sup 14} {Omega}-cm {at} 125 C). Various processes being developed to remove the capacitors from the silicon substrate and reattach them to ICs is described. In addition, a concept for interconnecting the capacitors using a repatterning process is discussed
First measurement of the spectral function at high energy and momentum in medium-heavy nuclei
The experiment E97-006 was performed at Jefferson Lab to measure the momentum
and energy distribution of protons in the nucleus far from the region of the
(approximate) validity of the mean field description, i.e. at high momentum and
energies. The occurrence of this strength is long known from occupation numbers
less than one. In the experiment reported here this strength was directly
measured for the first time. The results are compared to modern many-body
theories. Further the transparency factor of C12 was determined in the
Q^2-region of 0.6 to 1.8 (GeV/c)^2.Comment: Proceeding for Fourth International Workshop on Neutrino-Nucleus
Interactions in the Few-GeV Region 26.-29. Sept. 2005, Okayam
Mobile Daily Centre (Mdc) for Elder People with Cognitive Impairment: a Retrospective Observational Study
Introduction Trieste is a city characterized by a high mean age of the resident population, with 6,000 people with a cognitive impairment. Evidences show that is necessary to have a multidisciplinary approach, making alliances with the social network and families, while dealing with people with cognitive impairment. Because of this, the 3rd catchment district has developed a Mobile Daily Centre that aims to promote health, abilities and socialization giving the possibilities for these people to stay in a social context. Objectives Evaluating the impact of the Mobile Daily Centre on QoL of people with Cognitive Impairment. Aims Considering the rate of hospitalization and access to the first aid unit at the general hospital. Methods Retrospective Observational Study for the period between 01.01.2012 and 30.04.2014 on people in charge to the MDC. We have considered socio-demographic variables such as age, gender, care-givers; clinical variables such as psychopharmacotherapy and acetylcolinesterase-inhibitors drugs; rates of hospitalization, number of accesses to the first aid unit and of interventions of the MDC. Results in the period of the study 20 patients have been followed by the MDC; half of them had a psycho-pharmacological prescription. Very low rates of institutionalization have been detected. Conclusions MDC, in these small numbers, has shown to reduce the number of improper institutionalizations while guaranteeing to the elder people to maintain their abilities and socialization and to their care-givers periods of relief. Moreover, it promotes social inclusion and destigmatization. These results suggest that more territorial work and further studies should be done
Preparation of bio-functional textiles by surface functionalization of cellulose fabrics with caffeine loaded nanoparticles
In recent years transdermal drug delivery has aroused significant interest as a sustained and non-invasive way of administering active substances. The development of nanotechnology allowed the development of novel pharmaceutical formulations overcoming skin barrier. Furthermore, such nano-system can be combined with conventional fabrics to pave the way to a new generation of wearable drug delivery devices: bio-functional garments. First the NP were produced by flash nanoprecipitation technique (FNP), the production process was optimized to produce particles with suitable size for transdermal applications. The nanoparticles were characterized in terms of drug content by UV-visible spectroscopy and in terms of antioxidant activity by Electron Paramagnetic Resonance spectroscopy (EPR) coupled with spin trapping technique. The NPs were used to functionalize cotton and viscose-micromodal fabrics and the transdermal release properties were tested in vitro by Franz’s Cell experiment. FNP was proven to be an effective technique to produce tunable size particles. Moreover, the nanoencapsulated drug exhibited antioxidant activity. The release test evidenced a controlled release behavior effect providing evidence that the bio-functional textile is suitable for applications where sustained release and antioxidant properties are required
Designing a double-coated cathode with high entropy oxides by microwave-assisted hydrothermal synthesis for highly stable Li–S batteries
Nowadays, Li-S batteries are considered as one of the most promising alternatives to Li-ion technology in the near future, thanks to their high specific capacity and their significantly lower environmental impact and production costs. Consequently, many efforts have been directed to tackle with the inherent issues that affect Li-S batteries. One of the main problems is the so-called shuttle effect, which basically entails the unwanted migration of lithium polysulfides (LiPSs) from the cathode to the anode side, causing the degradation of the cell. Here, we report an effective strategy to restrain the shuttle effect and increase the kinetics at the cathode of the lithium-sulfur (Li-S) battery. A functional layer including high entropy oxides (HEO) coated onto the sulfur cathode allows to exploit the HEOs capability as promoter catalysts for the conversion of LiPSs. Pure HEO powders are synthesized by fast, highly efficient microwave irradiation, followed by heat treatment at 930 degrees C. The formation of highly crystalline HEO is confirmed by X-ray diffraction analysis. The LiPSs adsorption capability of HEO is evaluated by UV-vis and X-ray photoelectron spectroscopy analyses. The effect of the HEO-coated sulfur cathode on the electrochemical performance of the Li-S battery is studied by cyclic voltammetry and galvanostatic charge/discharge. The cell with double-coated cathode delivers an initial discharge capacity of 1173 mAh/g at C/10 with 45% capacity retention over 500 cycles at C/5, approaching similar to 99% coulombic efficiency.[GRAPHICS]
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