Avaliação da Umidade e da Resistência Superficial ao Cisalhamento em Argamassas de Revestimento Medida Através do Equipamento Vane Shear Test.

A utilização de argamassas de cimento Portland para a produção de revestimentos de tetos e paredes é uma realidade em obras civis no Brasil. Dentre as etapas de produção do revestimento argamassado, o acabamento superficial, conhecido popularmente como sarrafeamento, é tido como um procedimento empírico, onde o oficial pedreiro pressiona a superfície das argamassas com os dedos das mãos para definir em qual momento (resistência), após a aplicação da argamassa sob o substrato, deverá aplicar o cisalhamento com a régua niveladora. Este procedimento, por ser totalmente empírico, carece de um sistema de controle de qualidade para que falhas de execução e manifestações patológicas nesta etapa sejam menos recorrentes. Deste modo, este trabalho visa avaliar o comportamento da umidade das argamassas aplicadas no substrato, e a evolução da resistência das argamassas de revestimento no estado fresco tendo como base medidas superficiais de resistência ao cisalhamento com auxílio do aparelho Vane Shear Test, em que utilizou-se dois tipos de cimentos (CPII-Z-32 e CPIII-40-RS), dois tipos de substratos (bloco cerâmico e bloco de concreto), com e sem a aplicação de chapisco e dois traços comumente utilizados em obra, 1:1:6 e 1:2:9 (cimento:cal:areia). Os ensaios permitiram avaliar que a evolução da Resistência Superficial ao Cisalhamento (RSC) para blocos cerâmicos é de 4,45 vezes maior que o bloco de concreto. As argamassas produzidas com cimento CPII-Z-32 gera um crescimento de aproximadamente 30% maior quando comparada com argamassas produzidas com CPIII-40-RS. Já os substratos com chapisco e com traço 1:1:6 (cimento:cal:areia) geram um acréscimo de 15% na RSC quando comparados com a base não chapiscada e o traço 1:2:9 (cimento:cal:areia), respectivamente. Palavras-chave: Argamassa de revestimento; Resistência Superficial ao Cisalhamento (RSC); Vane Shear Test

UNIVERCM: the UNIversal VERsatile Computational Model for heterogeneous embedded system design

Modern embedded systems require a tight integration among several heterogeneous components including both digital and analog HW, as well as HW-dependent SW. Moreover, they have a strict interaction with the surrounding physical environment. Traditional approaches for modeling such systems rely either on homogeneous top-down methodologies or on co-simulation frameworks. The former are generally based on a single model of computation. Thus, they do not easily allow to integrate existing components built by using different formalisms. The latter assemble heterogeneous components without providing a rigorous formal support, thus making integration and validation a very hard tasks. This paper proposes UNIVERCM, a formal computational model that allows to represent with a uniform syntax and a precise semantics heterogeneous systems composed of SW, analog and digital HW, as well as the environment they are embedded in. UNIVERCM is not intended to be explicitly used to describe a system, but rather to automatically convert into a uniform representation different descriptions written by using heterogeneous modeling languages

UNIVERCM: the UNIversal VERsatile Computational Model for heterogeneous embedded system design

Modern embedded systems require a tight integration among several heterogeneous components including both digital and analog HW, as well as HW-dependent SW. Moreover, they have a strict interaction with the surrounding physical environment. Traditional approaches for modeling such systems rely either on homogeneous top-down methodologies or on co-simulation frameworks. The former are generally based on a single model of computation. Thus, they do not easily allow to integrate existing components built by using different formalisms. The latter assemble heterogeneous components without providing a rigorous formal support, thus making integration and validation a very hard tasks. This paper proposes UNIVERCM, a formal computational model that allows to represent with a uniform syntax and a precise semantics heterogeneous systems composed of SW, analog and digital HW, as well as the environment they are embedded in. UNIVERCM is not intended to be explicitly used to describe a system, but rather to automatically convert into a uniform representation different descriptions written by using heterogeneous modeling languages

UNIVERCM: the UNIversal VERsatile Computational Model for heterogeneous embedded system design

Modern embedded systems require a tight integration among several heterogeneous components including both digital and analog HW, as well as HW-dependent SW. Moreover, they have a strict interaction with the surrounding physical environment. Traditional approaches for modeling such systems rely either on homogeneous top-down methodologies or on co-simulation frameworks. The former are generally based on a single model of computation. Thus, they do not easily allow to integrate existing components built by using different formalisms. The latter assemble heterogeneous components without providing a rigorous formal support, thus making integration and validation a very hard tasks. This paper proposes UNIVERCM, a formal computational model that allows to represent with a uniform syntax and a precise semantics heterogeneous systems composed of SW, analog and digital HW, as well as the environment they are embedded in. UNIVERCM is not intended to be explicitly used to describe a system, but rather to automatically convert into a uniform representation different descriptions written by using heterogeneous modeling language

Brain penetration of local anaesthetics in the rat: Implications for experimental neuroscience.

Multiple experimental neuroscience techniques rely on the use of general anaesthesia to minimize the discomfort associated to animal restraint and to achieve a more effective control of relevant physiological parameters. In order to minimise potential interference on brain neuronal activity, such studies are typically conducted at low anaesthetic doses. This practice is often coupled to peripheral infiltration of local anaesthetics to provide supplementary analgesia and prevent sub-threshold activation of pain pathways that may confound central measurements of brain function. However, little is known of the effect of peripheral anaesthesia on central measurements of brain activity in small laboratory animal species. In order to begin to address this question, we measured total and free brain exposure of five different local anaesthetics following subcutaneous infiltration of analgesic doses in a surgical protocol widely used in rodent neuroimaging and electrophysiology studies. Notably, all the anaesthetics exhibited detectable total and free brain concentrations at all the time points examined. Lidocaine and mepivacaine showed the highest free brain exposures (>525 ng/g), followed by bupivacaine and ropivacaine (>70 ng/g). The ester-type local anaesthetic tetracaine produced the lowest free brain exposure (<8.6 ng/g). Our data suggest that peripheral administration of local anaesthetics in small laboratory animals could result in pharmacologically active brain exposures that might influence and confound central measurements of brain function. The use of the ester-type anaesthetic tetracaine produced considerably lower brain exposure, and may represent a viable experimental option when local anaesthesia is required

Novel approaches in cardiac imaging for non-invasive assessment of left heart myocardial fibrosis

In the past, the identification of myocardial fibrosis was only possible through invasive histologic assessment. Although endomyocardial biopsy remains the gold standard, recent advances in cardiac imaging techniques have enabled non-invasive tissue characterization of the myocardium, which has also provided valuable insights into specific disease processes. The diagnostic accuracy, incremental yield and prognostic value of speckle tracking echocardiography, late gadolinium enhancement and parametric mapping modules by cardiac magnetic resonance and cardiac computed tomography have been validated against tissue samples and tested in broad patient populations, overall providing relevant clinical information to the cardiologist. This review describes the patterns of left ventricular and left atrial fibrosis, and their characterization by advanced echocardiography, cardiac magnetic resonance and cardiac computed tomography, allowing for clinical applications in sudden cardiac death and management of atrial fibrillation

Subclinical Myocardial Fibrosis in Systemic Lupus Erythematosus as Assessed by Pulse-Cancellation Echocardiography: A Pilot Study

The aim of this study was to examine whether scar imaging echocardiography with ultrasound multi-pulse scheme (eSCAR) can detect subclinical myocardial involvement in systemic lupus erythematosus (SLE). We consecutively recruited SLE patients and controls matched for age, sex, and cardiovascular risk factors. Participants with cardiac symptoms or a prior history of heart disease were excluded. All participants underwent eSCAR and speckle tracking echocardiography (STE) with global longitudinal strain (GLS) assessment. SLE patients were assessed for disease activity and were followed up for 12 months. Myocardial scars by eSCAR were observed in 19% of SLE patients, almost exclusively localized at the inferoseptal myocardial segments, and in none of the controls. GLS was significantly lower in most myocardial segments of SLE patients compared with the controls, especially in the inferoseptal segments. eSCAR-positive SLE patients received a higher cumulative and current dose of prednisone, and had significantly higher levels of anti-dsDNA antibodies (p = 0.037). eSCAR-positive patients were at higher risk of having SLE flares over follow-up (hazard ratio: 4.91; 95% CI 1.43–16.83; p = 0.0001). We identified inferoseptal myocardial scars by eSCAR in about one-fifth of SLE patients. Subclinical myocardial involvement was associated with glucocorticoid use and anti-dsDNA antibodies

Effects of Aortic Valve Replacement on Left Ventricular Diastolic Function in Patients With Aortic Valve Stenosis

The afterload increase imposed by severe aortic valve stenosis (AS) creates concentric left ventricular (LV) remodeling and diastolic dysfunction (DD), which are both markers of poor clinical outcome. Ideally, a correctly timed surgery for isolated AS can reverse the LV remodeling. However, data on LV DD after aortic valve replacement (AVR) are sparse and contrasting. Aims of the study are to define the markers of a favorable evolution of the DD at follow-up. Patients with severe isolated AS, scheduled for AVR were prospectively enrolled. Transthoracic echocardiography with DD assessment was performed before surgery, and at 12 months after surgery. Global LV longitudinal and circumferential strain, peak atrial longitudinal and contraction strain (PALS, PACS) were obtained at baseline. LV septal biopsy to assess fibrosis was performed at the time of AVR. Sixty-seven patients were enrolled, age 72 \ub1 8 years, 66% female, ejection fraction 61 \ub1 8%, E/e' 13 \ub1 6, PALS 23 \ub1 7%. Normal estimated left atrial pressure was detected in 19/67 (28%) versus 43/67 (64%) at follow-up (p &lt;0.0001). In the 37 patients with biopsy available, fibrosis was 24 \ub1 12%. PALS and AS severity were correlated with LV fibrosis (R2\u202f=\u202f0.19; p\u202f=\u202f0.006, and R2\u202f=\u202f0.15; p\u202f=\u202f0.02, respectively). PALS (odds ratio: 1.19 [1.05 to 1.41], p\u202f=\u202f0.02) and PACS (odds ratio: 1.24 [1.06 to 1.50], p\u202f=\u202f0.006) were the only baseline noninvasive parameters independently associated with normal left atrial pressure at follow-up. Mean follow-up time was 791 \ub1 245 days, and 8 (12%) patients had cardiovascular events (death, hospital admission due to heart failure or ischemic disease, and onset of atrial fibrillation). Myocardial fibrosis (p\u202f=\u202f0.05), baseline PALS (p\u202f=\u202f0.004), and PACS (p\u202f=\u202f0.03) were associated with cardiovascular events. In conclusion, LV diastolic function generally improves after AVR for severe AS. Baseline PALS, PACS, and LV fibrosis were related to the DD and clinical outcome at follow-up; these parameters might cue a better diastolic response to the afterload correction

Status of the APEX Project at LBNL

The Advanced Photo-injector Experiment (APEX) at the Lawrence Berkeley National Laboratory is focused on the development of a high-brightness high-repetition rate (MHz-class) electron injector for X-ray FEL applications. The injector is based on a new concept gun, utilizing a normal conducting 186 MHz RF cavity operating in CW mode in conjunction with high quantum efficiency photocathodes capable of delivering the required repetition rates with available laser technology. The APEX activities are staged in 3 main phases. In Phases 0 and I, the gun is tested at its nominal energy of 750 keV and several different photocathodes are tested at full repetition rate. In Phase II, a pulsed linac is added for accelerating the beam at several tens of MeV to reduce space charge effects and measure the high-brightness performance of the gun when integrated in an injector scheme. At Phase II energies, the radiation shielding configuration of the bunker where APEX is located limits the repetition rate to a maximum of several Hz. Phase 0 is under commissioning, Phase I components under fabrication, and initial activities for Phase II are underway. This paper presents an update on the status of all these activities.Director of the Office of Science of the US Department of EnergyContract no. DEAC02-05CH1123

Advanced photoinjector experiment photogun commissioning results

The Advanced Photoinjector Experiment (APEX) at the Lawrence Berkeley National Laboratory is dedicated to the development of a high-brightness high-repetition rate (MHz-class) electron injector for x-ray free-electron laser (FEL) and other applications where high repetition rates and high brightness are simultaneously required. The injector is based on a new concept rf gun utilizing a normal-conducting (NC) cavity resonating in the VHF band at 186 MHz, and operating in continuous wave (cw) mode in conjunction with high quantum efficiency photocathodes capable of delivering the required charge at MHz repetition rates with available laser technology. The APEX activities are staged in three phases. In phase 0, the NC cw gun is built and tested to demonstrate the major milestones to validate the gun design and performance. Also, starting in phase 0 and continuing in phase I, different photocathodes are tested at the gun energy and at full repetition rate for validating candidate materials to operate in a high-repetition rate FEL. In phase II, a room-temperature pulsed linac is added for accelerating the beam at several tens of MeV to reduce space charge effects and allow the measurement of the brightness of the beam from the gun when integrated in an injector scheme. The installation of the phase 0 beam line and the commissioning of the VHF gun are completed, phase I components are under fabrication, and initial design and specification of components and layout for phase II are under way. This paper presents the phase 0 commissioning results with emphasis on the experimental milestones that have successfully demonstrated the APEX gun capability of operating at the required performance