1,721,036 research outputs found
Design and Control of a Reclining Chair with Soft Pneumatic Cushions
Full text linkThe object of this work is the control of a reclining chair with active cushions used to optimize the interaction of the human with the chair and to avoid the formation of sores on the skin. The cushion system, already presented in other works, consists of air-cell actuators distributed according to the risk that pressure ulcers on the skin can be generated in certain areas. In this work, four cushions are designed and controlled for four parts of the human body: 1) head; 2) back; 3) buttocks; 4) heels. Cushions are used to design a reclining chair that can be moved between two configuration limits: a) chair; b) bed. The four cushions can provide real-time pressure mapping with closed-loop control, which allows to identify critical points on the body surface where pressure ulcers could form. The control systems for the single air-cell and for all cushions are designed and simulated using the software MATLAB/Simulink, presenting very interesting results
Flexible Pneumatic Actuators: a comparison between the McKibben and the straight fibres musc
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Float-Ram: A Sustainable Machine for Buildings Made by Compressed Earth Blocks
Full text linkThis article describes a sequence of research, design, prototyping and utilization of a new manually operated press, which has the purpose of facilitating a construction technology that uses compressed earth blocks, CEB. Buildings and houses made of CEB have better quality than traditional in poor region. They are also economical, robust, aesthetically pleasing, and sustainable from an environmental point of view. The research is addressed to some targets of the SDG 11, Sustainable Cities and Communities: (i) “ensure access for all to adequate, safe and affordable housing and basic services and upgrade slums”; (ii) “support least developed countries, including through financial and technical assistance, in building sustainable and resilient buildings utilizing local materials”. The paper presents the project path, the results and finally the impact in a specific context, the rural areas in Tanzania
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Modelling, design and control of a new seat-cushion for pressure ulcers prevention
No full textPressure ulcers are a frequent complication in patients having limited activity and mobility (e.g., elderly people, spinal cord injury patients, people with disabilities, etc.). The aim of this work is the conceptual design, modelling and control of a new seat cushion for pressure ulcers prevention. The whole system (constituted by the seat cushion equipped with a real-time pressure mapping with closed-loop control) is designed to identify the critical points on the human skin, before pressure ulcers creation, and to be able to distribute the contact pressure between the human and cushion avoiding wound creation. The seat cushion is constituted by soft air-cells actuated by air flow. To define the shape and size of the soft air-cells, finite element simulations are carried out, analysing the internal volume reduction with external loads application to reproduce the variable stiffness. The data obtained by finite element analysis are used to simulate inflation and deflation of the soft bubble air-cells. Finally, the control systems of a single air-cell and of the whole cushion are designed and simulated. The novelty of our work consists in the conception of a seat cushion able to recognise higher and lower risk zones of pressure ulcer generation on the human skin and to provide compensation automatically. This work can therefore be considered in line with the sustainable development goals recently launched by the EU Commission
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Use of Pneumatic Artificial Muscles in a Passive Upper Body Exoskeleton
No full textThis paper presents a preliminary study on a novel upper body exoskeleton conceived for human effort reduction in uncomfortable operations. The exoskeleton is constituted by a light wearable structure energized by two McKibben pneumatic artificial muscles, which could be used in passive (such as springs) or active mode (such as actuators). In this work, the modelling and the design of the exoskeleton is presented. The performance of the exoskeleton is evaluated considering two commercial McKibben muscles used in passive mode. The results underline that the exoskeleton can be adapted to compensate the weight of the upper limbs and a load in the hands of an operator under defined working conditions
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