scholarly journals A Review on Sliding Vane and Rolling Piston Compressors

Machines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 125
Author(s):  
Kuan Thai Aw ◽  
Kim Tiow Ooi

Rotary compressors have been employed in heating and cooling for more than a century and are ubiquitous in daily life but there has not been any comprehensive record of their development and technological advances. This review paper attempts to provide a comprehensive account of the advances in R&D and design evolution of these rotary compressors since their inception, namely the sliding vane compressor, rolling piston compressor, and their design variants in open literature. This is to showcase the current state-of-the-art for these compressors so that researchers can use it as a basis for future work. Based on authors’ insight, inter-disciplinary research combined with advancements in ‘disruptive’ technology such as artificial intelligence and advancements in additive manufacturing might be a promising research direction to bring about improvements in rotary compressor performance to meet mankind’s growing needs for cooling and heating applications.

2019 ◽  
Vol 63 (4) ◽  
pp. 308-318 ◽  
Author(s):  
Balázs Farkas ◽  
Jenő Miklós Suda

The evaluation of a newly designed oil-free rotary compressor is presented based on transient 3D Computational Fluid Dynamics (CFD) simulations. The simulations are performed at low compression ratios and low pressure ratios and low rotational speeds. To place the results into context, the data presented in related literature was processed and summarized. The methods related to the CFD model of the newly designed compressor were developed, summarized and evaluated. The accessed CFD data are in good agreement with the results of the former rolling piston compressor related investigations. The oil free operation prevents the contamination of the working fluid from lubricant. Since the compressor is planned to work in open cycle within the sensitive environment of thermal heat sources contamination free operation has to be accomplished. However, oil-free operation also results in significantly lower performance based on the modelling results.


2011 ◽  
Vol 317-319 ◽  
pp. 2063-2068
Author(s):  
Ai Nong Geng ◽  
Kui Hua Geng ◽  
Xin Mo Li

A new type of stationary blade rotary compressor is developed to overcome the rolling piston compressor’s weaknesses such as severe leaking loss and friction waste. The new compressor has unique sealing structures and friction-reducing techniques, featuring in that the compressor adopts a stationary blade whose out-end is hermetically fastened to the cylinder’s inner wall and the blade’s two side-ends are hermetically fastened to the end-covers which respectively set in both ends of the cylinder. Due to that the cylinder, the blade and the end-covers all are closely fitted to each other, the leakage and friction occurred from these parts are completely eliminated. This paper introduces the compressor’s working principle and structure characteristics, deduces the calculation formulas for displacement volume, chamber pressure and thermodynamic properties, and discusses the design principles of compressor structure parameters and what effects these parameters have on leakage and friction. The research result shows that the stationary blade compressor, in comparison with the conventional rolling piston compressor, has displayed some unique advantages in seal property, friction reduction, manufacturing and assembling techniques.


Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5095
Author(s):  
Prateek Benhal ◽  
David Quashie ◽  
Yoontae Kim ◽  
Jamel Ali

Insulator based dielectrophoresis (iDEP) is becoming increasingly important in emerging biomolecular applications, including particle purification, fractionation, and separation. Compared to conventional electrode-based dielectrophoresis (eDEP) techniques, iDEP has been demonstrated to have a higher degree of selectivity of biological samples while also being less biologically intrusive. Over the past two decades, substantial technological advances have been made, enabling iDEP to be applied from micro, to nano and molecular scales. Soft particles, including cell organelles, viruses, proteins, and nucleic acids, have been manipulated using iDEP, enabling the exploration of subnanometer biological interactions. Recent investigations using this technique have demonstrated a wide range of applications, including biomarker screening, protein folding analysis, and molecular sensing. Here, we review current state-of-art research on iDEP systems and highlight potential future work.


Author(s):  
Endang Wahyu Pamungkas ◽  
Valerio Basile ◽  
Viviana Patti

AbstractAbusive language is an important issue in online communication across different platforms and languages. Having a robust model to detect abusive instances automatically is a prominent challenge. Several studies have been proposed to deal with this vital issue by modeling this task in the cross-domain and cross-lingual setting. This paper outlines and describes the current state of this research direction, providing an overview of previous studies, including the available datasets and approaches employed in both cross-domain and cross-lingual settings. This study also outlines several challenges and open problems of this area, providing insights and a useful roadmap for future work.


VASA ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 35-46
Author(s):  
Stephen Hofmeister ◽  
Matthew B. Thomas ◽  
Joseph Paulisin ◽  
Nicolas J. Mouawad

Abstract. The management of vascular emergencies is dependent on rapid identification and confirmation of the diagnosis with concurrent patient stabilization prior to immediate transfer to the operating suite. A variety of technological advances in diagnostic imaging as well as the advent of minimally invasive endovascular interventions have shifted the contemporary treatment algorithms of such pathologies. This review provides a comprehensive discussion on the current state and future trends in the management of ruptured abdominal aortic aneurysms as well as acute aortic dissections.


Author(s):  
Paul B. Miller

This chapter charts new frontiers of scholarly inquiry in fiduciary law. The chapter first orients the reader by taking stock of the current state of play in fiduciary scholarship. It then identifies a range of important questions that should inspire future work in the field. More specifically, it identifies pressing questions of legal theory (conceptual and normative analysis), economic and empirical legal studies (including classical and behavioral economic analysis), and historical and sociological inquiry. The chapter also raises questions of interest to private law theorists and scholars interested in exploring the significance of fiduciary principles within various subfields, from trust and corporate law to health law and legal ethics.


2021 ◽  
Vol 11 (5) ◽  
pp. 2068
Author(s):  
William Villegas-Ch. ◽  
Xavier Palacios-Pacheco ◽  
Milton Roman-Cañizares ◽  
Sergio Luján-Mora

Currently, the 2019 Coronavirus Disease pandemic has caused serious damage to health throughout the world. Its contagious capacity has forced the governments of the world to decree isolation and quarantine to try to control the pandemic. The consequences that it leaves in all sectors of society have been disastrous. However, technological advances have allowed people to continue their different activities to some extent while maintaining isolation. Universities have great penetration in the use of technology, but they have also been severely affected. To give continuity to education, universities have been forced to move to an educational model based on synchronous encounters, but they have maintained the methodology of a face-to-face educational model, what has caused several problems in the learning of students. This work proposes the transition to a hybrid educational model, provided that this transition is supported by data analysis to identify the new needs of students. The knowledge obtained is contrasted with the performance presented by the students in the face-to-face modality and the necessary parameters for the transition to this modality are clearly established. In addition, the guidelines and methodology of online education are considered in order to take advantage of the best of both modalities and guarantee learning.


Author(s):  
Anatoli A. Borissov ◽  
Alexander A. Borissov ◽  
Kenneth K. Kramer

Each year, the users in the U.S. alone spend over $100 billion on various type of engines to produce power — electrical, mechanical, and thermal. Despite technological advances, most all of these power generation systems have only been fine tuned: the engine efficiencies may have been improved slightly, but the underlying thermodynamic principles have not been modified to effect a drastic improvement. The result is that most engines in service today suffer from two major problems: low fuel efficiency and emission of high levels of polluting gases in the exhaust gases. The current state of propulsion engines or distributed generation technologies using heat engines shows an average efficiency of between 20% and 40%. These low efficiencies in a high–cost energy market indicate a great need for more efficient technologies. This paper describes a new method of achieving a very high efficiency, namely optimizing every stage of the thermodynamic process-Brayton cycle. Two modified processes, such as isothermal compression and recuperation, add about 35% efficiency to the conventional Brayton cycle, making 60% efficiency for modified Brayton cycle. By utilizing a positive displacement compressor and expander with a novel vortex combustion chamber and a vortex recuperator, high levels of efficiency with low emissions and noise are possible. The prototype engine with low RPM and high torque has been built which use continuous combustion of different fuels under a constant pressure. First results of the engine’s components testing are presented.


Neurosurgery ◽  
2008 ◽  
Vol 62 (suppl_2) ◽  
pp. SHC633-SHC642 ◽  
Author(s):  
James M. Drake

Abstract THE SURGICAL MANAGEMENT of hydrocephalus has undergone incredible changes over the past generation of neurosurgeons, including dramatic improvements in imaging, especially computed tomographic scanning and magnetic resonance imaging, and remarkably innovative advances in cerebrospinal fluid valve technology, complex computer models, and endoscopic equipment and techniques. In terms of overall patient outcomes, however, one could conclude that things are a little better, but “not much.” This frustrating yet fascinating dichotomy between technological advancements and clinical outcomes makes hydrocephalus, first described by the ancients, as one of the most understated and complex disorders that neurosurgeons treat. The challenge to the next generation of neurosurgeons is to solve this vexing problem through better understanding of the basic science, improved computer models, additional technological advances, and, most importantly, a broad-based, concerted multidisciplinary attack on this disorder. This review focuses on the evolution of surgery for hydrocephalus over the last 30 years, the current state of the art of hydrocephalus treatment, and what appear to be the most promising future directions.


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