Empathy as an Aspect of Critical Thought and Action in Design and Technology

Author(s):  
Bill Nicholl
2020 ◽  
Vol 21 (6) ◽  
pp. 619
Author(s):  
Kostandin Gjika ◽  
Antoine Costeux ◽  
Gerry LaRue ◽  
John Wilson

Today's modern internal combustion engines are increasingly focused on downsizing, high fuel efficiency and low emissions, which requires appropriate design and technology of turbocharger bearing systems. Automotive turbochargers operate faster and with strong engine excitation; vibration management is becoming a challenge and manufacturers are increasingly focusing on the design of low vibration and high-performance balancing technology. This paper discusses the synchronous vibration management of the ball bearing cartridge turbocharger on high-speed balancer and it is a continuation of papers [1–3]. In a first step, the synchronous rotordynamics behavior is identified. A prediction code is developed to calculate the static and dynamic performance of “ball bearing cartridge-squeeze film damper”. The dynamic behavior of balls is modeled by a spring with stiffness calculated from Tedric Harris formulas and the damping is considered null. The squeeze film damper model is derived from the Osborne Reynolds equation for incompressible and synchronous fluid loading; the stiffness and damping coefficients are calculated assuming that the bearing is infinitely short, and the oil film pressure is modeled as a cavitated π film model. The stiffness and damping coefficients are integrated on a rotordynamics code and the bearing loads are calculated by converging with the bearing eccentricity ratio. In a second step, a finite element structural dynamics model is built for the system “turbocharger housing-high speed balancer fixture” and validated by experimental frequency response functions. In the last step, the rotating dynamic bearing loads on the squeeze film damper are coupled with transfer functions and the vibration on the housings is predicted. The vibration response under single and multi-plane unbalances correlates very well with test data from turbocharger unbalance masters. The prediction model allows a thorough understanding of ball bearing turbocharger vibration on a high speed balancer, thus optimizing the dynamic behavior of the “turbocharger-high speed balancer” structural system for better rotordynamics performance identification and selection of the appropriate balancing process at the development stage of the turbocharger.


2010 ◽  
Vol 6 (2) ◽  
pp. 71 ◽  
Author(s):  
Lindsay A Smith ◽  
Amit Bhan ◽  
Mark J Monaghan ◽  
◽  
◽  
...  

Echocardiography provides excellent realtime imaging of the heart, making it the imaging modality of choice immediately before, during and after cardiac interventional procedures. It helps to guide case selection and execution of the intervention, evaluates the effects of the intervention and enables early detection of complications. Advances in the design and technology of medical devices and delivery systems, coupled with demand for alternative non-surgical therapies for common medical problems, have led to an increase in the volume, variety and complexity of non-coronary cardiac interventional procedures performed. Many of these procedures require a multidisciplinary team approach and demand optimal imaging to ensure successful outcomes. The aim of this article is to review the expanding role of echocardiography in non-coronary interventional cardiology in adults.


2000 ◽  
Author(s):  
Krishna Shenai ◽  
Philip Neudeck ◽  
Gene Schwarze

2017 ◽  
Vol 6 (Especial) ◽  
pp. 105
Author(s):  
Dante Choque-Caseres

In Latin America, based on the recognition of Indigenous Peoples, the identification of gaps or disparities between the Indigenous and non-Indigenous population has emerged as a new research interest. To this end, capturing Indigenous identity is key to conducting certain analyses. However, the social contexts where the identity of Indigenous persons are (re)produced has been significantly altered. These changes are generated by the assimilation or integration of Indigenous communities into dominant national cultures. Within this context, limitations emerge in the use of this category, since Indigenous identity has a political and legal component related to the needs of the government. Therefore, critical thought on the use of Indigenous identity is necessary in an epistemological and methodological approach to research. This article argues that research about Indigenous Peoples should evaluate how Indigenous identity is included, for it is socially co-produced through the interaction of the State and its institutions. Thus, it would not necessarily constitute an explicative variable. By analyzing the discourse about Aymara Indigenous communities that has emerged in the northern border of Chile, this paper seeks to expose the logic used to define identity. Therefore, I conclude that the process of self-identification arises in supposed Indigenous people, built and/or reinforced by institutions, which should be reviewed from a decolonizing perspective and included in comparative research.


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