Search results for " AIS"
showing 10 items of 17 documents
Aislamiento de cocaína y benzoilecgonina en muestras de orina por extracciones líquido-líquido y en fase sólida y confirmación por Cromatografía líqu…
2006
El consumo ilícito de cocaína se ha incrementado extraordinariamente en los últimos años, por lo que resulta indispensable el desarrollo de metodologías seguras, rápidas y eficientes para su detección. En este trabajo se desarrollo una técnica de HPLC de fase reversa con detector de UV para identificar y cuantificar a la cocaína y la benzoilecgonina, con resultados satisfactorios en los parámetros del control de calidad.Se realizó un estudio de recobrado para el aislamiento de la cocaína y la benzoilecgonina en orina con extracciones liquido liquido y en fase sólida con tres tipos de columnas comerciales (Bond Elut Certify, Extrelut 3 y Supelclean LC-18). Las fracciones obtenidas con la ext…
Prior Precision Modulates the Minimization of Auditory Prediction Error
2019
International audience; The predictive coding model of perception proposes that successful representation of the perceptual world depends upon canceling out the discrepancy between prediction and sensory input (i.e., prediction error). Recent studies further suggest a distinction to be made between prediction error triggered by non-predicted stimuli of different prior precision (i.e., inverse variance). However, it is not fully understood how prediction error with different precision levels is minimized in the predictive process. Here, we conducted a magnetoencephalography (MEG) experiment which orthogonally manipulated prime-probe relation (for contextual precision) and stimulus repetition…
DETERMINATION AND ANALYSIS OF HEAD AND CHEST PARAMETERS BY SIMULATION OF VEHICLE-TEENAGER IMPACT
2013
This paper reports the results of multi-body numerical simulation of a vehicle crash with a teenager pedestrian. A previous technique utilized for adult pedestrian impact is applied. The work starts with the determination of the masses for the various segments of the body of a teenager with a total mass of 45 kg and then switches to the construction of the dummy and the middle-class vehicle in the Visual Nastran environment. Simulations are performed for both frontal impacts and lateral impacts, when the vehicle is travelling at a constant speed and when the vehicle is braking, following the Euro NCAP rules on the subject. The results are analysed by calculating the values of the head inju…
Numerical modelling of the linear friction welding process
2010
Linear friction welding (LFW) is a solid-state joining process applied to non-axisymmetric components. LFW involves joining of materials through the relative reciprocating motion of two components under an axial force. In such process the heat source is given by the frictional forces work decaying into heat determining a local softening of the material and proper bonding conditions due to both the temperature increase and the local pressure of the two edges to be welded. In the present work the authors present a numerical model of the linear friction welding process of AISI 1045 parts. The numerical model allowed to highlight the process mechanics and the physical conditions which must be r…
Utilidad de la ecografía Doppler infrapoplítea en pacientes con sospecha de enfermedad tromboembólica venosa
2017
La enfermedad tromboembólica venosa (ETEV) es una enfermedad vascular compleja con una patogénesis multifactorial. Su importancia radica en su alta prevalencia y en la morbimortalidad asociada. Agrupa dos presentaciones clínicas mayores, la más frecuente es la trombosis venosa profunda (TVP) y la más temida por su riesgo de mortalidad es el tromboembolismo pulmonar (TEP). Se identifican principalmente dos localizaciones de TVP en los miembros inferiores (MMII): la trombosis proximal (TP) cuando afecta a las venas profundas del hueco poplíteo y proximales a éste, y la trombosis distal cuando afecta a las venas profundas y musculares de la pantorrilla. La trombosis distal puede darse de forma…
Numerical simulation of linear fiction welding (LFW) processes
2011
Solid state welding processes are becoming increasingly important due to a large number of advantages related to joining ''unweldable'' materials and in particular light weight alloys. Linear friction welding (LFW) has been used successfully to bond non-axisymmetric components of a range of materials including titanium alloys, steels, aluminum alloys, nickel, copper, and also dissimilar material combinations. The technique is useful in the research of quality of the joints and in reducing costs of components and parts of the aeronautic and automotive industries.LFW involves parts to be welded through the relative reciprocating motion of two components under an axial force. In such process t…
Reti, Nuovi Settori e Sostenibilità
2014
Negli ultimi anni, anche a seguito del perdurare della crisi economica, gli studiosi delle diverse discipline, ivi compresi gli scienziati regionali, si sono interrogati su come riconnettersi a un sentiero virtuoso di crescita economica e sociale ai diversi livelli territoriali. Non vi è dubbio che la crisi abbia stimolato, in molti ambiti, la scoperta di nuovi paradigmi o la rivalutazione di schemi concettuali che stentavano ad affermarsi. Partendo da tale premessa, l’oggetto di questo volume è proprio quello di riflettere su come alcuni di questi nuovi paradigmi (in tema di reti, nuovi settori, sostenibilità) abbiano orientato l’indagine empirica territoriale e di raccogliere ed evidenzia…
Michele Federico Sciacca
2010
Profilo della personalità filosofica e religiosa dello Sciacca, con particolare riferimento al suo ruolo nella cultura filosofica italiana del dopoguerra.
Photoelectrochemical monitoring of rouging and de-rouging process on AISI 316L for chemical reactors
2016
The food and fine-chemical industry has for a long time been troubled by red brown to dark violet deposits in distillation columns, storage vessels and distribution systems for purified water and clean steam. Owing to the visual appearance of those deposits, the phenomena was referred as rouge. Although formation of rouge, i.e. rouging, is a commonly known phenomenon in stainless steel systems, the basic mechanism is still not fully understood. The phenomenon causes precipitation of iron as fine red-brown ferric oxide or hydroxide particles. Moreover adherent discoloration of the stainless steel surface is often observed in conjunction with the loosely adhered rouge particles. The affected …
Behavior of Calcium Phosphate–Chitosan–Collagen Composite Coating on AISI 304 for Orthopedic Applications
2022
Calcium phosphate/chitosan/collagen composite coating on AISI 304 stainless steel was investigated. Coatings were realized by galvanic coupling that occurs without an external power supply because it begins with the coupling between two metals with different standard electrochemical potentials. The process consists of the co-deposition of the three components with the calcium phosphate crystals incorporated into the polymeric composite of chitosan and collagen. Physical-chemical characterizations of the samples were executed to evaluate morphology and chemical composition. Morphological analyses have shown that the surface of the stainless steel is covered by the deposit, which has a very r…