0000000000846211
AUTHOR
A. Castiglia
showing 10 related works from this author
Chalcogenide thin films for direct resistors fabrication and trimming
2004
Abstract The fabrication of thin film resistors based on Ge–Sb–Te chalcogenide alloys is proposed. By exploiting the phase change properties of the deposited film, a laser beam is used for inducing a transition from high to low resistivity along selected paths. Conductivity changes as high as four orders of magnitude can be routinely achieved. This candidates the technique for maskless fabrication of compact precision resistors for a variety of applications.
Suppression of leakage currents in GaN-based LEDs induced by reactive-ion etching damages
2008
Forward and reverse leakage currents in GaN/InGaN multi-quantum well light-emitting diodes (LEDs) are caused by reactive-ion etching (RIE) damages during device patterning. A method to recover the damaged surfaces, based on a chemical etch in KOH: ethylene-glycol is described. Leakage currents decrease of more than a factor of 10 and are completely suppressed in most of devices.
Blue lasing at room temperature in high quality factor GaN/AlInN microdisks with InGaN quantum wells
2007
The authors report on the achievement of optically pumped III-V nitride blue microdisk lasers operating at room temperature. Controlled wet chemical etching of an AlInN interlayer lattice matched to GaN allows forming inverted cone pedestals. Whispering gallery modes are observed in the photoluminescence spectra of InGaN/GaN quantum wells embedded in the GaN microdisks. Typical quality factors of several thousands are found (Q>4000). Laser action at similar to 420 nm is achieved under pulsed excitation at room temperature for a peak power density of 400 kW/cm(2). The lasing emission linewidth is down to 0.033 nm.
Salt extraction from lime-based mortars: An experimental study using different poultice formulations
2020
Abstract The extractive capability of soluble salts in poultices treatments currently used in mortar conservation (ArbocelTM plus sepiolite; ArbocelTM, sepiolite and sand; Westox-Cocoon®) were tested to evaluate their efficiency and compatibility with specific mortar substrate. The pore size distribution of the experimental mortar substrate and of the blank dried poultices were preliminarily accomplished by mercury intrusion porosimetry (MIP). Desalination tests were carried out on specifically-formulated mortars after capillary absorption of Na2SO4 0.3 M solution. The efficiency of salt extraction was measured by means of electrical conductivity meter and ion chromatography. Among the test…
Moisture absorption, thermal conductivity and noise mitigation of clay based plasters: The influence of mineralogical and textural characteristics
2016
Abstract Three pre-mixed clay based plasters successfully employed in green building practices in several European countries (Spain, France, Germany, and United Kingdom), mainly used for interior wall coating and finishing, were tested in this paper. Their compositional and textural characteristics as well as plastic behaviour were investigated through a multi-analytical approach in a previous paper. A natural earth (Terra Rossa red soil sampled in north-western Sicily), theoretically appropriate for the production of earthen plaster, was also subjected to the same analytical routine and compared with the three commercially available products. Humidity control capacity by the determination …
Current status of AlInN layers lattice-matched to GaN for photonics and electronics
2007
We report on the current properties of Al1-x InxN (x approximate to 0.18) layers lattice- matched ( LM) to GaN and their specific use to realize nearly strain- free structures for photonic and electronic applications. Following a literature survey of the general properties of AlInN layers, structural and optical properties of thin state- of- the- art AlInN layers LM to GaN are described showing that despite improved structural properties these layers are still characterized by a typical background donor concentration of ( 1 - 5) x 10(18) cm(-3) and a large Stokes shift (similar to 800 meV) between luminescence and absorption edge. The use of these AlInN layers LM to GaN is then exemplified …
A comparative study of different formulations of poultices for soluble salts removal from experimental plasters
2017
Soluble salts extractive capability of some commercial materials currently used in plaster restoration sector (ArbocelTM plus sepiolite; ArbocelTM, sepiolite and sand; Westox-Cocoon®) were tested in the present study, with the aim to evaluate their efficiency, their compatibility with the substrates as well as in terms of costs and duration of intervention. The three poultice products were first characterized in terms of porosimetric distribution. The desalination tests have been performed on samples of plaster specially formulated and made at the laboratory. Experimental specimens were then brought into contact with a solution of Na2SO4 0.3 M. The efficiency rating of these different types…
SHORT-TERM VARIABILITY OF 24-H SYSTOLIC BLOOD PRESSURE IS ASSOCIATED WITH MICROALBUMINURIA IN PATIENTS WITH PRIMARY HYPERTENSION
2015
Introduction: Limited and conflicting data are available about the association between short-term blood pressure (BP) variability and urinary albumin excretion rate (uAER). Aim: To analyse the relationships between microalbuminuria, defined as an uAER between 20 and 200 lg/min, and short-term BP variability, assessed as average real variability (ARV), weighted standard deviation (SD) of 24-h BP, and as SD of daytime and nighttime BP. Methods: The study population consisted of 316 untreated essential hypertensive patients with normal estimated glomerular filtration rate ([60 ml/min/1.73m2), which underwent 24-h ambulatory BP monitoring and 24-h uAER determination. Results: Microalbuminuria w…
SHORT-TERM VARIABILITY OF 24H SYSTOLIC BLOOD PRESSURE IS ASSOCIATED WITH MICROALBUMINURIA IN PATIENTS WITH PRIMARY HYPERTENSION
2015
Objective: Limited and conflicting data are available about the association between shortterm blood pressure (BP) variability and urinary albumin excretion rate (uAER). The objective of our study was to analyze the relationships between microalbuminuria, defined as an uAER between 20 and 200mg/ min, and shortterm BP variability, assessed as average real variability (ARV), weighted standard deviation (SD) of 24h BP, and as SD of daytime and nighttime BP. Design and method: The study population consisted of 315 untreated essential hypertensives with normal estimated glomerular filtration rate (> 60ml/min/1.73 m2), which underwent 24h ambulatory BP monitoring and 24h uAER determination. Result…
[OP.5C.05] SERUM URIC ACID IS INCREASED IN NORMOTENSIVE OBESE CHILDREN WITH A PARENTAL HYSTORY OF HYPERTENSION
2017
Objective: Increased uric acid levels are closely associated with new-onset hypertension in children, and pilot studies showed that pharmacological lowering of uric acid may reduce blood pressure (BP) in obese pediatric patients. Nevertheless, controversy remains concerning a direct causative role of serum uric acid (SUA) in the pathogenesis of essential hypertension (EH). Our study was aimed to determine if normotensive obese children and adolescent offspring of adults with EH show SUA levels different than those of pediatric subjects in whom there is non family history of EH. Design and method: Fifty-nine obese normotensive children and adolescents, attending for metabolic assessment the …