119,493 research outputs found
Yacht performance monitoring in real sailing conditions
No full textIn this paper a multi-method approach is used to setup and validate a monitoring system applied to a small sailing boat during real sailing conditions. This monitoring system is able to transform the data coming from some typical devices installed on board into information about the deformed state of the boat. GPS, Wind Data Logger and cameras have been installed on the boat to measure its route and speed, the apparent wind velocity and direction and the positions of the crew members. These data are processed to determine the equilibrium of the boat and estimate the loads applied on it. Then, a CAD/FEM model calculates the effects of these loads on the boat shape. The resulting deformed model is compared with measurements of local strains obtained with Electrical Resistance strain gauges applied on the hull and on reinforcements of the boat. Onboard measuring devices are real-time monitored with a home-made software while the numerical prediction of the global boat deformation is obtained a posteriori once FEM computation is achieved. A test at sea has been performed to check the efficiency of the system: data computed with the proposed procedure have been compared with those coming from the field test
B-Scan image analysis for position and shape defect definition in plates
No full textDefinition of size, shape and location of defects into a mechanical component is of extreme importance in the manufacturing industry in general and particularly in high-tech applications, and in applications that can become dangerous due to the structural failure of mechanical components. In this paper, a laser-UT system has been used to define position and shape of internal defects in aluminum plates. An infrared pulsed laser is used to generate ultrasonic waves in a point of the plate and a CW laser interferometer is used as receiver to acquire the out-of-plane displacements due to the ultrasonic waves in another point of the plate. The method consists of acquiring a B-Scan map on which some information on the defects in the mechanical component are visible. Storing the characteristics of the wave reflected by the defect and acquired in the B-Scan, the detection and the drawing of the defect is possible. The acquisition of the times of arrival of the waves reflected by the defect from the B-scan allows defining large parts of the shape of the defect. The times of arrival are acquired from the B-scan by analyzing the colour variations due to the wave reflected by the defect. The experiments operated from both sides of the plate allow drawing the defect in a virtual image of the plate section, from which the definition of defect shape and position can be determined
A multi-technique simultaneous approach for the design of a sailing yacht
No full textIn this paper, most significant steps involved during the whole process of designing a sailing yacht are outlined. In particular, a novel simultaneous approach has been proposed to optimize the design process of a sailing yacht. Analytical resistance prediction models are simultaneously used with CAD systems and computational fluid dynamics tools to find, in the more effective way, the best solution for the chosen design conditions. As a general rule, in fact, once the target point has been decided, task of the designer is the definition of those systems of aerodynamic and hydrodynamic forces that are in equilibrium when the boat sails at its target. Unfortunately, a multi-purpose yacht does not exist. If the target point is in upwind sailing then, performances will be better for such a condition and worse for others. The effectiveness of the proposed procedure has been tested by means of a case study related to the design of hull, appendages and sails of a 15” yacht subject to box-rules, designed and manufactured at the University of Palermo
PUMPING APPARATUS AND CORRESPONDING OPERATING METHOD
No full textPumping apparatus (10) for pumping concrete, or similar material, comprising at least one pumping unit (11) having both a first pumping cylinder (16) and a second pumping cylinder (17), and also a first pumping piston (21) and a second pumping piston (22) both mobile with a respectively alternating motion inside respective chambers (19, 20) present in the first cylinder (16) and in the second cylinder (17), respectively. The apparatus comprises a motor (31), preferably electric, to drive the first and second piston (21, 22) with an alternating motion by means of suitable movement means (26, 27)
A new ESO-based method to find the optimal topology of structures subject to multiple load conditions
No full textIn the field of topology optimization problems, the Evolutionary Structural Optimization (ESO) method is one of the most popular and easy to use. When dealing with problems of reasonable difficulty, the ESO method is able to give very good results in reduced times and with a limited request of computational resources. Generally, main applications of this method are addressed to the definition of the optimal topology of a component subjected to a single load condition.In this work, a new methodology, based on the ESO approach, is introduced for the study of the optimal topology of a component subjected to multiple load conditions. The new procedure, entirely developed in the APDL programming language, has been tested with a holed plate subject to two different load conditions; the obtained results are promising in terms of mass reduction and structural performances
Numerical study of the components positioning influence on the stability of a reverse shoulder prosthesis
No full textAim of this paper is to setup a novel procedure able to analyze performances of a reverse shoulder prosthesis when different geometrical configurations are assumed. Nowadays, such a prosthesis is widely used but, because of its novelty, data in literature give poor information about performances and limits to its applicability. The activity has been divided into the following steps. At the beginning the shape of the prosthesis has been digitally acquired via a 3D scanner. Then, CAD models of all prosthetic components have been geometrically optimized in a way to obtain final entities suitable for numerical simulations. After that, CAD assemblies have been created between prosthetic components and bones (humerus and scapula) involved in the shoulder joint. Following step has been the setup of numerical finite element method models to simulate use conditions. To this scope, analyses have been performed in accordance with experimental conditions found in literature. Stability conditions have been verified under the action of horizontal and vertical instability loads with different version angles between humerus and the humeral implant. In particular, the stability ratios of the prosthesis have been calculated for the analysed loading conditions. Obtained results show how the positioning has a great influence on the shoulder stability and allow the definition of guidelines for the application of this prosthesi
Influence of the metaphysis positioning in a new reverse shoulder prosthesis
No full textAim of this work is to investigate the behaviour of a new reverse shoulder prosthesis, characterized by a humeral metaphysis with a variable offset, designed to increase the range of movements and to reduce the impingement. In particular, by means of virtual prototypes of the prosthesis, different offset values of the humeral metaphysis have been analysed in order to find the best positioning able to maximize the range of movements of the shoulder joint. The abduction force of the deltoid, at different offset values, has been also estimated. The study has been organized as follows. In the first step, the point clouds of the surfaces of the different components of the prosthesis have been acquired by a 3D scanner. This kind of scanner allows to convert camera images into three-dimensional models by analysing the moiré fringes. In the second step, the acquired point clouds have been post-processed and converted into CAD models. In the third step, all the 3D reconstructed models have been imported and assembled through a CAD system. After, a collision analysis has been performed to detect the maximum angular positions of the arm at different metaphysis offset values. In the last step, FEM models of shoulder joint with the new prosthesis have been created. Different analyses have been performed to estimate how the deltoid abduction force varies depending on the offset of the humeral tray. The study allowed to understand how the offset of the metaphysis affects the performances of the shoulder. The obtained results can be effectively used to give surgeons useful guidelines for the installation of these kinds of implants
Quality of the information provided by ChatGPT for patients in breast plastic surgery: are we already in the future?
No full textIntroduction
In the recent years Artificial Intelligence has grown in popularity also in the field of Plastic Surgery;
For patients is becoming more and more common to use internet to gather plastic surgery
information and chatbot based on AI, such as ChatGPT, could be used for answering patient’s
questions.
The aim of this study was to assess the quality of medical information provided by ChatGPT
regarding three of the most common procedure performed in breast surgery: Breast Reconstruction,
Breast reduction and Augmentation mammaplasty.
Methods
The quality of information was evaluated through the Expanded EQIP scale. Responses where
collected from a pool made by ten resident doctors in Plastic Surgery and then processed by SPSS
software vers. 28.0.
Results
The analysis of the contents provided from ChatGPT showed a sufficient quality of the information
in all the topic selected, with an high bias in terms of distribution of the score between the different
items. There was a critical lack in the “Information data field” (0/6 score in all the 3 investigations)
but a very high overall evaluation concerning the “Structure data” (>7/11 in all the 3 investigations).
Conclusion
At the present time, AI could be an useful tool for patients, but some critical issues that need to be
faced from engineers and developers are still present. It’s definitely possible that in the future
models like ChatGPT will play an important role in improving patient’s consciousness about
medical procedures and surgical interventions, but their role must be considered ancillary to the one
of the surgeon
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