Search results for " Ultrasonic"

Left ventricular volume determination using colour superpositioning of contrast echocardiograms

1995

Abstract Objective: To delineate the endocardium, selective colouring of contrast regions in left ventricular contrast echocardiograms was performed using digital image processing. Methods: Volume determinations were performed in end-diastolic and end-systolic frames before and after the injection of contrast agent into the left ventricle and were compared to cineventriculograms in 30 patients by two independent investigators. Results: The mean end-diastolic volume measured was 114 ± 44 ml in the native, 235 ± 79 ml in the contrast, 175 ± 70 ml in the color-superimposed (observer 1), and 187 ± 79 ml in the cineventriculographic images. Thus, native echocardiograms underestimated angiographi…

Medical Student Ultrasound Education, a WFUMB Position Paper, Part I, response to the letter to the Editor.

2019

0263: Percutaneous US-Guided Hematoma Aspiration to Reduce Recovery Time of II Grade Muscle Strain in Elite Soccer Players

2009

Advances in microgeophysics for engineering and cultural heritage

2009

A large number of unconventional investigations have been implemented, tested, and validated in the field of microgeophysics, with the aim being to solve specific diagnostic and/or monitoring problems regarding civil engineering and cultural heritage studies. The investigations were carried out using different tomographic 2D and 3D approaches as well as different energy sources, namely sonic, ultrasonic and electromagnetic (radar) waves, electric potential fields, and infrared thermography. Many efforts have been made to modify instruments and procedures in order to improve the resolution of the surveys as well as to greatly reduce the time of the measurements without any loss of informatio…

Correlation of Tibial Low-Frequency Ultrasound Velocity with Femoral Radiographic Measurements and BMD in Elderly Women

2009

The ultrasonic axial transmission technique has been proposed as a method for cortical bone characterization. Using a low enough center frequency, Lamb modes can be excited in long bones. Lamb waves propagate throughout the cortical bone layer, which makes them appealing for characterizing bone material and geometrical properties. In the present study, a prototype low-frequency quantitative ultrasonic axial transmission device was used on elderly women (n = 132) to investigate the relationships between upper femur geometry and bone mineral density (BMD) and tibial speed of sound. Ultrasonic velocities (V) were recorded using a two-directional measurement set-up on the midtibia and compared …

Nanocompositi a base polimerica a durabilità modulata mediante il controllo delle proprietà antiossidanti di nanostrutture carboniose

Assessing the Open Trenches in Screening Railway Ground-Borne Vibrations by Means of Artificial Neural Network

2009

Reducing ground borne vibrations in urban areas is a very challenging task in railway transportation. Many mitigation measures can be considered and applied; among these open trenches are very effective. This paper deals with the study of the effect, in terms of reduction of vertical and horizontal displacements and velocities, of the open trenches. 2D FEM simulations have been performed and several open trench configurations have been analysed varying the main geometric features such as width and depth, distance from the rail, thickness of the soil layer over the rigid bedrock, type of the ground, ratio between the depth of the trench, and the thickness of the soil layer. For quantifying t…

Challenges Associated with Byproducts Valorization—Comparison Study of Safety Parameters of Ultrasonicated and Fermented Plant-Based Byproducts

2020

In order to promote the efficient use of byproducts from the production of plant-based beverages, which still contain a large amount of nutritional and functional compounds, microbiological and chemical safety characteristics should be evaluated and, if needed, improved. Many challenges are associated with byproducts valorization, and the most important ones, which should be taken into account at the further steps of valorization, are biological and chemical safety. For safety improving, several technological treatments (biological, physical etc.) can be used. In this study, the influence of low-frequency ultrasonication (US) and fermentation with Lactobacillus casei LUHS210 strain, as phys…

Numerical methods for a nonlinear impact model: A comparative study with closed-form corrections

2011

A physically based impact model-already known and exploited in the field of sound synthesis-is studied using both analytical tools and numerical simulations. It is shown that the Hamiltonian of a physical system composed of a mass impacting on a wall can be expressed analytically as a function of the mass velocity during contact. Moreover, an efficient and accurate approximation for the mass outbound velocity is presented, which allows to estimate the Hamiltonian at the end of the contact. Analytical results are then compared to numerical simulations obtained by discretizing the system with several numerical methods. It is shown that, for some regions of the parameter space, the trajectorie…

Spin caloric transport from density-functional theory

2019

Spin caloric transport refers to the coupling of heat with spin transport. Its applications primarily concern the generation of spin currents and control of magnetisation by temperature gradients for information technology, known by the synonym spin caloritronics. Within the framework of ab initio theory, new tools are being developed to provide an additional understanding of these phenomena in realistic materials, accounting for the complexity of the electronic structure without adjustable parameters. Here, we review this progress, summarising the principles of the density-functional-based approaches in the field and presenting a number of application highlights. Our discussion includes th…