Current Status, Design and Performance Trends for the Regenerative Flow Compressors and Pumps

Author(s):  
Mukarrum Raheel ◽  
Abraham Engeda

Regenerative flow compressors and pumps, hereafter called RFC/RFP have found many applications in industry; still they are the most neglected turbomachines in the family of dynamic compressors. The number of publications existing in literature is very small compared to the large number of papers about the centrifugal and axial turbocompressors. This paper gives a detail discussion of fundamentals and working principle of regenerative turbomachines. Regenerative compressors are compared with centrifugal compressors and the importance of regenerative turbomachines in low specific speed range is emphasized. The major findings of available literature on regenerative turbomachine are summarized. The current status, limitations and some of the challenges faced by RFC/RFP are assessed in context of performance improvement. The paper concludes with an overview of ongoing research and future directions to be followed for performance improvement of this neglected class of turbomachines.

2007 ◽  
Vol 42 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Ja. Blagodyr ◽  
A. Bilinsky ◽  
K. Martynyuk-Lototsky ◽  
O. Lohvynenko ◽  
N. Virun

Overview and Performance of the Ukrainian SLR Station "Lviv-1831"The paper presents the current status and performance of the SLR station "Lviv-1831". The present equipment allows ranging of satellite not lower than 900 km with a single shot precision about 50 mm. The team works over system upgrade and performance improvement. It includes: neutral filters wheel developing for equilibration of the amplitude of reflected pulses from different satellites, building up the shutter in the face of PMT for the spurious light pulses blocking. Also the new adjusting of the telescope optical mechanical systems was made. After that investigation the new telescope error model was built with an accuracy 20arcsec that allowed at the first time test ranging of the "shadowed" satellite passes. In the near future the team will finish installation and testing of the new PMT Hamamatsu H6780. Maiden upgrades should better the performance and ranging accuracy by the factor of 2-3.


2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
J. Nejadrajabali ◽  
A. Riasi ◽  
S. A. Nourbakhsh

Regenerative pump is a low specific speed and rotor-dynamic turbomachine capable of developing high heads at low flow rates. In this paper, a numerical study has been carried out in order to investigate the effect of blade angle on the performance of a regenerative pump. Two groups of impellers were employed. The first type has symmetric angle blades with identical inlet/outlet angles of ±10°, ±30°, and ±50° and the second group has nonsymmetric angle blades in which the inlet angle was set to 0° and six different angles of ±10°, ±30°, and ±50° were designed for the outlet of the blades. A total of 12 impellers, as well as primary radial blades impeller, were investigated in this study. The results showed that all forward blades have higher head coefficients than radial blades impeller at design flow coefficient. It was found that regenerative pumps with symmetric angle forward blades have better performance than other types. Also, it is worth mentioning that the highest head coefficient and efficiency occur at angle+10<β<+30of symmetric angle blades. It was found that the maximum efficiency occurs at angle of +15.5° by curve fitting to the data obtained from numerical simulations for symmetric angle forward blades.


2016 ◽  
Vol 15 (2) ◽  
pp. 55-65 ◽  
Author(s):  
Lonneke Dubbelt ◽  
Sonja Rispens ◽  
Evangelia Demerouti

Abstract. Women have a minority position within science, technology, engineering, and mathematics and, consequently, are likely to face more adversities at work. This diary study takes a look at a facilitating factor for women’s research performance within academia: daily work engagement. We examined the moderating effect of gender on the relationship between two behaviors (i.e., daily networking and time control) and daily work engagement, as well as its effect on the relationship between daily work engagement and performance measures (i.e., number of publications). Results suggest that daily networking and time control cultivate men’s work engagement, but daily work engagement is beneficial for the number of publications of women. The findings highlight the importance of work engagement in facilitating the performance of women in minority positions.


Author(s):  
Luis Cláudio de Jesus-Silva ◽  
Antônio Luiz Marques ◽  
André Luiz Nunes Zogahib

This article aims to examine the variable compensation program for performance implanted in the Brazilian Judiciary. For this purpose, a survey was conducted with the servers of the Court of Justice of the State of Roraima - Amazon - Brazil. The strategy consisted of field research with quantitative approach, with descriptive and explanatory research and conducting survey using a structured questionnaire, available through the INTERNET. The population surveyed, 37.79% is the sample. The results indicate the effectiveness of the program as a tool of motivation and performance improvement and also the need for some adjustments and improvements, especially on the perception of equity of the program and the distribution of rewards.


2019 ◽  
Vol 25 (25) ◽  
pp. 2772-2787 ◽  
Author(s):  
Raghu P. Mailavaram ◽  
Omar H.A. Al-Attraqchi ◽  
Supratik Kar ◽  
Shinjita Ghosh

Adenosine receptors (ARs) belongs to the family of G-protein coupled receptors (GPCR) that are responsible for the modulation of a wide variety of physiological functions. The ARs are also implicated in many diseases such as cancer, arthritis, cardiovascular and renal diseases. The adenosine A3 receptor (A3AR) has emerged as a potential drug target for the progress of new and effective therapeutic agents for the treatment of various pathological conditions. This receptor’s involvement in many diseases and its validity as a target has been established by many studies. Both agonists and antagonists of A3AR have been extensively investigated in the last decade with the goal of developing novel drugs for treating diseases related to immune disorders, inflammation, cancer, and others. In this review, we shall focus on the medicinal chemistry of A3AR ligands, exploring the diverse chemical classes that have been projected as future leading drug candidates. Also, the recent advances in the therapeuetic applications of A3AR ligands are highlighted.


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