928 resultados para 240501 Acoustics and Acoustical Devices


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Abstract Study objective: The arousal state changes during spinal anesthesia. It is not clear if BIS and others devices could monitor the induced neuroaxial blockade sedation. Our objective was evaluate BIS and entropy values when spinal anesthesia is done. Design: We developed a prospective study. Patients: 40 patients were included in this study, ASA I-III, over 60 years old, undergoing spinal anesthesia, without premedication scheduled for orthopedics procedures. Intervention: Spinal anesthesia was performed with the unseated volunteer in the lateral decubitus position with a 25-gauge Whitacre needle at L2-L3 space, andanesthesia was done with 12 mg of 0.5% hyperbaric bupivacaine. Patients were positioned supine for 5 min after spinal anesthesia. Measurements: Observer’s Assessment of Alertness/Sedation OAA/S, response (RE) and state entropy (SE) and BIS, and standard hemodynamic measures. Main results: Statistical analysis were performed by Wilcoxon test or ANOVA, p<0.05 was considered statistically significant.RE and BIS showed a better correlation with the OAA/S scale values (Pk 0.81 and 0.82) than SE (Pk 0.69). The OAA/S, RE and SE showed significative differences from basal values after 30 min of neuroaxial anesthesia (ANOVA p<0.05). BIS showed differences after 40 min (ANOVA p<0.05). There were no differences between BIS and RE values along the study (ANOVA p>0.05). Conclusions: The spinal anesthesia decreased the cortical activity and these were founded by OAA/S scale and depth anesthetics monitors. OAA/S was a more sensitive value of this induced sedation. BIS and RE showed a better correlation with OAA/S scale than SE.

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This paper presents and discusses the use of Bayesian procedures - introduced through the use of Bayesian networks in Part I of this series of papers - for 'learning' probabilities from data. The discussion will relate to a set of real data on characteristics of black toners commonly used in printing and copying devices. Particular attention is drawn to the incorporation of the proposed procedures as an integral part in probabilistic inference schemes (notably in the form of Bayesian networks) that are intended to address uncertainties related to particular propositions of interest (e.g., whether or not a sample originates from a particular source). The conceptual tenets of the proposed methodologies are presented along with aspects of their practical implementation using currently available Bayesian network software.

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Currently, acoustic isolation is one of the problems raised with building construction in Spain. The publication of the Basic Document for the protection against noise of the Technical Building Code has increased the demand of comfort for citizens. This has created the need to seek new composite materials that meet the new required acoustical building codes. In this paper we report the results of the newly developed composites that are able to improve the acoustic isolation of airborne noise. These composites were prepared from polypropylene (PP) reinforced with mechanical pulp fibers from softwood (Pinus radiata). Mechanical and acoustical properties of the composites from mechanical pulp (MP) and polypropylene (PP) have been investigated and compared to fiberglass (FG) composites. MP composites had lower tensile properties compared with FG composites, although these properties can be improved by incorporation of a coupling agent. The results of acoustical properties of MP composites were reported and compared with the conventional composites based on fiberglass and gypsum plasterboards. Finally, we suggest the application of MP composites as a light-weight building material to reduce acoustic transmitions

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Most ventricular assist devices (VADs) currently used in infants are extracorporeal. These VADs require long-term anticoagulation therapy and extensive surgery, and two devices are needed for biventricular support. We designed a biventricular assist device based on shape memory alloy that reproduces the hemodynamic effects of cardiomyoplasty, supporting the heart with a compressing movement, and evaluated its performance in a dedicated mockup system. Nitinol fibers are the device's key component. Ejection fraction (EF), cardiac output (CO), and generated systolic pressure were measured on a test bench. Our test bench settings were a preload range of 0-15 mm Hg, an afterload range of 0-160 mm Hg, and a heart rate (HR) of 20, 30, 40, and 60 beats/min. A power supply of 15 volts and 3.5 amperes was necessary. The EF range went from 34.4% to 1.2% as the afterload and HR increased, along with a CO from 180 to 6 ml/min. The device generated a maximal systolic pressure of 25 mm Hg. Cardiac compression for biventricular assistance in child-sized heart using shape memory alloy is technically feasible. Further testing remains necessary to assess this VAD's in vivo performance range and its reliability.

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AIMS: As growing concerns exist regarding phthalate exposure, which could be teratogenic, carcinogenic or induce reproductive toxicity, we aimed to review the evidence of the risks due to the use of medical devices containing di(2-ethylhexyl)phthalate in hospitalized neonates. METHODS: We reviewed the literature, searching through medical literature databases (Pubmed, MEDLINE, EBM reviews, Cochrane database, Embase and Google Scholar) using the following keywords: phthalate, di(2-ethylhexyl)phthalate, newborn and neonate. RESULTS: We identified several associations with short and long term health dangers, mainly subfertility, broncho-pulmonary dysplasia, necrotising enterocolitis, parenteral nutrition associated cholestasis and neuro-developmental disorders. These data are based mainly on animal or observational human studies. CONCLUSION: Clinicians must be aware of the potential risks due to phthalate exposure in the NICU. Di(2-ethylhexyl)phthalate containing materials should be identified and alternative devices should be considered. There is a need to improve knowledge in this area.

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Los nuevos hábitos de consumo de medios en el marco de la convergencia digital están propiciando un cambio en las estrategias de los medios de comunicación. Mientras unos usuarios siguen prefiriendo la radio, la televisión y la prensa tradicional para informarse otros participan de la experiencia digital en internet (blogs, redes sociales...) y dispositivos móviles, etc. En este panorama es complicado precisar dónde nace y termina el contenido o hasta qué punto es la participación del usuario quien (re) construye la información; así los contenidos mutan y se diluyen en varios soportes. En este contexto, la prensa local también vive las consecuencias del nuevo paradigma y asume los retos del reacomodo del sector ante la nueva realidad. Esta comunicación presenta las conclusiones del estudio cualitativo con entrevistas en profundidad a los responsables de medios locales en Cataluña sobre sus usuarios, contenidos y soportes en el marco de la convergencia digital.

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We report on the growth of epitaxial YBa2Cu3O7 thin films on X-cut LiNbO3 single crystals. The use of double CeO2/YSZ buffer layers allows a single in-plane orientation of YBa2Cu3O7, and results in superior superconducting properties. In particular, surface resistance Rs values of 1.4 m¿ have been measured at 8 GHz and 65 K. The attainment of such low values of Rs constitutes a key step toward the incorporation of high Tc materials as electrodes in photonic and acoustic devices.

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A photographic and video record of the project to recreate and reconstruct the glass floor for the opening between the ground and first floors in the rotunda of the Iowa State Capitol. The original glass floor was removed in the early 20th century, but the decision was made to put a new one in to help improve the acoustics and air flow in the building.

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Interventional paediatric and congenital cardiology is expanding at a rapid pace. Validated techniques (such as aortic or pulmonary valve dilatations and occlusion of persistent ductus arteriosus and atrial septal defects) are improving thanks to the use of smaller introducers and sheaths, low-profile balloons and novel devices. Moreover, catheter-based interventions have emerged as an attractive alternative to surgery in other fields: pulmonary valve replacement, balloon and stent implantation for native and recurrent coarctation, and percutaneous closure of ventricular septal defects. On the other hand, percutaneous interventions in the paediatric population may be limited by patient size or the anatomy of the defect. Hybrid approaches involving both cardiac interventionists and surgeons are being developed to overcome these limitations. Based on a better understanding of cardiac development, fetal cardiac interventions are being attempted in order to alter the history of severe obstructive lesions. Finally, some interventional procedures still carry a low success rate-for example, pulmonary vein stenosis, even with the use of conventional stents. Biodegradable stents and devices are being developed and may find an application in this setting as well as in others. The purpose of this review is to highlight the advances in paediatric interventional cardiology since the beginning of the third millennium.

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Monodispersed colloidal crystals based on silica sub-micrometric particles were synthesized using the Stöber-Fink-Bohn process. The control of nucleation and coalescence result in improved characteristics such as high sphericity and very low size dispersion. The resulting silica particles show characteristics suitable for self-assembling across large areas of closely-packed 2D crystal monolayers by an accurate Langmuir-Blodgett deposition process on glass, fused silica and silicon substrates. Due to their special optical properties, colloidal films have potential applications in fields including photonics, electronics, electro-optics, medicine (detectors and sensors), membrane filters and surface devices. The deposited monolayers of silica particles were characterized by means of FESEM, AFM and optical transmittance measurements in order to analyze their specific properties and characteristics. We propose a theoretical calculation for the photonic band gaps in 2D systems using an extrapolation of the photonic behavior of the crystal from 3D to 2D. In this work we show that the methodology used and the conditions in self-assembly processes are decisive for producing high-quality two-dimensional colloidal crystals by the Langmuir-Blodgett technique.

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This document presents the results of a state-of-practice survey of transportation agencies that are installing intelligent transportation sensors (ITS) and other devices along with their environmental sensing stations (ESS) also referred to as roadway weather information system (RWIS) assets.

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Des de fa una dècada es parla de la convergència digital, que ha propiciat la conjunció de la informàtica amb els mitjans de comunicació i la interconnexió en xarxa. Actualment circulen amb facilitat suports vells i nous cada vegada més flexibles. La conseqüència per als usuaris és que avui disposen d’una varietat àmplia de continguts connectats permanentment en qualsevol lloc i en qualsevol moment, a través de diverses plataformes i amb una convivència rica i complexa. En aquest context, aquest article mostra les conclusions d’un estudi de camp sobre l’ús, el consum i les preferències de suports i de continguts de la comunicació digital per part de grups d’infants, de joves, d’adults i de gent gran a Catalunya.

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In this paper are described the results of a research project that had the objective of developing construction procedures for restoring load transfer in existing jointed concrete pavements and of evaluating the effectiveness of the restoration methods. A total of 28 test sections with various load transfer devices were placed. The devices include split pipe, figure eight, vee, double vee, and dowel bars. Patching materials used on the project included three types of fast-setting grouts, three brands of polymer concrete, and plain portland cement concrete. The number and spacing of the devices and dowel bars were also variables in the project. Dowel bars and double vee devices were used on the major portion of the project. Performance evaluations were based on deflection tests conducted with a 20,000-lb axle load. Horizontal joint movement measurements and visual observations were also made. The short-term performance data indicate good results with the dowel bar installations regardless of patching materials. The sections with split pipe, figure eight, and vee devices failed in bond during the first winter cycle. The results with the double vee sections indicate the importance of the patching material to the success or failure of the load transfer system: some sections are performing well and other sections are performing poorly with double vee devices. Horizontal joint movement measurements indicate that neither the dowel bars nor the double vee devices are restricting joint movement.

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We report on the growth of epitaxial YBa2Cu3O7 thin films on X-cut LiNbO3 single crystals. The use of double CeO2/YSZ buffer layers allows a single in-plane orientation of YBa2Cu3O7, and results in superior superconducting properties. In particular, surface resistance Rs values of 1.4 m¿ have been measured at 8 GHz and 65 K. The attainment of such low values of Rs constitutes a key step toward the incorporation of high Tc materials as electrodes in photonic and acoustic devices.

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Matkailualan palvelujen kehitystä on pitkään hidastanut standardien ja yhtenäisten toimintatapojen puute. Tässä diplomityössä tarkastellaan standardien merkitystä teknisesti kehittyneille matkailupalveluille ja esitellään TravelGate Finland -hankkeen tuloksena syntynyttä mobiilisovellusta. Kehittyneiden matkaviestinverkkojen ja älypuhelimien ansiosta yhä useammilla ihmisillä on mahdollisuus käyttää matkustaessaan erilaisia mobiilipalveluja. Matkailualan yritysten tarjoamia palveluita ei kuitenkaan ole juurikaan saatavilla, koska niiden kehittäminen on standardien puuttumisen takia hankalaa ja kallista. TravelGate Finland -hankkeen tuloksena matkailualan käyttöön määriteltiin uusi rajapintakirjasto, jonka avulla uusien Internet- ja mobiilipalvelujen kehittäminen helpottuu. Uusien rajapintojen ja toimintatapojen avulla toteutettiin Symbian-älypuhelimissa toimiva mobiilisovellus, jonka avulla matkailijat voivat etsiä heitä lähellä olevien matkailukohteiden sijainnin ja perustiedot veloituksetta.