Ricerca del migliore compromesso delle caratteristiche meccaniche degli acciai per utensili a caldo dopo bonifica. Comportamento della tenacità per effetto dei tempi prolungati alle temperature di nitrurazione

La bonifica degli acciai per utensili a caldo rende stabile il comportamento termomeccanico dovuto allo stressa cui sono sottoposti i componenti per pressocolata o stampaggio a caldo. L’interesse di questo studio è rivoltoa tutti i margini di miglioramento industrialmente applicabili tramite trattamento termico per ottenere unaresa ed una performance che rispettino le attese anche a fronte di differenti stati di fornitura del materiale.Utensili e stampi, dopo trattamento termico e finitura, sono spesso nitrurati. Indipendentemente dal metodo, lanitrurazione sottopone il pezzo a temperature site nell’intervallo della fragilità da rinvenimento con più lunghepermanenze. L’indagine è stata anche condotta con lo scopo di verificare in che modo ed in quale misura siainfluenzata la tenacità di un materiale bonificato con durezza e resilienza caratteristiche di uno stampo dipressocolata simulando la tipica temperatura e i tempi adottati per la nitrurazion

Acute Dacryocystitis with Empyema of the Lacrimal Sac: Is Immediate Endoscopic Dacryocystorhinostomy Justified?

Objectives. To evaluate the efficacy of endoscopic dacryocystorhinostomy (Endo-DCR) in the treatment of acute dacryocystitis with lacrimal sac empyema (ADLSE). Design. Case series with chart review. Setting. Academic tertiary center. Patients. The study included 26 consecutive patients who underwent Endo-DCR for ADLSE between August 2005 and December 2013. Main Outcome Measures. The success of the procedure was defined as complete complaint relief and DCR patency. Data on the time from referral to surgery, postoperative complications, and revision surgery are also reported. Results. The present patient series included 4 males (15.4%) and 22 females (84.6%) (mean age, 66 years). The mean time between referral and surgery was 0.88 days and the mean follow-up time was 29 months. All patients showed immediate relief from symptoms, with no ADLSE recurrences. Complete success was achieved in 25 (96.2%) cases; the only failure was in a patient who had previously undergone radioiodine treatment. In this case, revision Endo-DCR was not successful. The only perioperative complication (3.8%) was epistaxis in a patient who required revision surgery under general anesthesia. The definitive success rate was 96.2% after primary and revision surgery. Conclusions. Endo-DCR enables rapid resolution of ADLSE with a very high success rate. Immediate surgery may reduce the risk of skin fistulization and/or orbital complications. DCR shrinkage and lacrimal obstruction are unlikely with Endo-DCR since the procedure is performed on an enlarged sac. The main advantage of Endo-DCR, compared with external DCR, is the absence of a skin incision in an inflamed and infected field

A 0.4 nJ Excitation Energy Bridge-to-Digital Converter for Implantable Pulmonary Artery Pressure Monitoring

This paper presents an energy-efficient, duty-cycled, and spinning excitation bridge-to-digital converter (BDC) suitable for measuring the pulmonary artery pressure of heart failure patients with an implantable system. The duty-cycled bridge uses resistances of 6.2 kΩ and, with a supply of 1.2 V, consumes 0.4 nJ excitation energy. A novel spinning method is applied to the bridge and the capacitive DAC simultaneously in such a way to achieve an offset-independent digital output and to eliminate the need for complex instrumentation amplifiers with offset-reduction techniques or calibration. The SAR ADC fabricated in 0.18-μm CMOS consumes 19 nW at 1.2 V. With a sampling rate of 1 kS/s, the converter achieves the ENOB of 9.2 bits

Video Decoder Reconfigurations and AVS Extensions in the New MPEG Reconfigurable Video Coding Framework

In 2004, ISO/IEC SC29 better known as MPEG started a new standard initiative aiming at facilitating the deployment of multi-format video codec design and to enable the possibility of reconfiguring video codecs using a library of standard components. The new standard under development is called MPEG Reconfigurable Video Coding (RVC) framework. Whereas video coding tools are specified in the RVC library, when a new decoder is reconfigured choosing in principle any (sub)-set of tools, the corresponding bitstream syntax, described using MPEG-21 BSDL schema, and the associated parser need to be respectively derived and instantiated reconfiguration by reconfiguration. Therefore, the development of an efficient systematic procedure able to instantiate efficient bitstream parsing and particularly variable length decoding is an important component in RVC. This paper introduces an efficient data flow based implementation of the variable length decoding (VLD) process particularly adapted for the instantiation and synthesis of CAL parsers in the MPEG RVC framework