Torsional vibration problems continue to occur in reciprocating engine and compressor installations. This is due in part to the fact that reciprocating equipment can produce significantly more torsional excitation than rotating machinery such as turbines, centrifugal compressors, and centrifugal pumps. The purpose of this tutorial is to raise awareness of torsional vibration problems that can o...

A complete and advanced numerical simulation model of the thermal and fluid-dynamic performance of hermetic reciprocating compressors has been developed and is used in the optimization Electrolux compressor design. During the last few years several global experimental validations have been carried out. A detailed instrumentation of a commercial reciprocating compressor for household refrigerato...

An irreversible Maisotsenko reciprocating Brayton cycle (MRBC) model is established using the finite time thermodynamic (FTT) theory and taking the heat transfer loss (HTL), piston friction loss (PFL), and internal irreversible losses (IILs) into consideration in this paper. A calculation flowchart of the power output (P) and efficiency (η) of the cycle is provided, and the effects of the mass ...

In 6 patients with the Wolff-Parkinson-White (WPW) syndrome, repetitive, almost continuous (incessant) reciprocating atrioventricular (AV) tachycardia has been shown to arise when the sinus cycle length was shortened to a critical point, at which unidirectional block occurred without the classical feature of PR prolongation. Though this phenomenon superficially resembles an aspect of chronic in...

Power reciprocating saws are used in surgical procedures to cut bone. Improved cutting rates are desirable in order to reduce operative time and improve patient outcome. A fixture was developed to test the effect of blade speed on cutting rate of bovine cortical bone. It was hypothesized that the volumetric cutting rate would increase in a linear manner for a fixed stroke length and a constant ...

The mechanisms of reciprocating tachyeardias were studied in three patients with WPW syndrome using the catheter technic of His bundle recordings. In the first case it could not be determined with certainty whether the tachycardias involved two anatomically independent fascicles or a single longitudinally dissociated pathway. They were terminated by carotid sinus pressure, which caused A-V noda...

The mechanisms of reciprocating tachyeardias were studied in three patients with WPW syndrome using the catheter technic of His bundle recordings. In the first case it could not be determined with certainty whether the tachycardias involved two anatomically independent fascicles or a single longitudinally dissociated pathway. They were terminated by carotid sinus pressure, which caused A-V noda...

The present paper is a numerical and experimental comparative study of hermetic and semi-hermetic reciprocating compressors working with carbon dioxide as fluid refrigerant against the conventional R134a hermetic compressors. When cooling conditions for one-stage compressor type (i.e., evaporation temperatures between 7.2oC and –10oC) have been considered, the numerical and experimental results...

This article introduces a new type of magnetic sealing mechanism that reduces the lubrication oil pollution and media gaseous leakage in general reciprocating machinery including air compressors and refrigerators. The feasible function and reliable performance of this new sealing mechanism are introduced and analyzed in this paper. The computer aided design, modeling and analysis are being used...

Objective: The purpose of this study was to evaluate the effect using single-file with different tapered coronal flaring files on dentinal crack. Material and Methods: Human extracted mandibular premolars (n=128) were selected divided into four groups (n=32) based instruments; Group 1, One Flare; 2, Endoflare; 3, Gates Glidden Drills; 4, Control Group. Specimens subgroups single file system (n=...