Ultrasonic transducers play a significant role in generating and receiving the acoustic waves in ultrasonic flowmeters. Depending on the required accuracy, the ultrasonic transducers can be installed either in one pair or more in an ultrasonic flowmeter. The main part of an ultrasonic transducer is its piezoceramic element. In this work, four piezoceramic elements with different diameter to thi...

It was thought previously that cardiac muscle gap junctions provide low-resistance connections between cells and permit the local-circuit current to flow. Some evidences show that myocardial cells may not require low-resistance connections for successful propagation of the action potential (AP). It seems that some other types of mechanisms must be involved in AP propagation. In this article, we...

the present study was undertaken to investigate the role of banana extract (be) on synchronous plantlet formation from seeds of dendrobium lituiflorum lindl. the seedlings formed on modified knudson c (kc) medium supplemented with 20% (v/v) be had significantly high fresh and dry weights. morphologically uniform plantlets with elongated leaves and well developed roots were formed on kc medium w...

Background: Lemon verbena (Lippia citriodora H.B.K.) is an aromatic and medicinal plant of family Verbenaceae, which cultivated in North region of Iran. Objective: Evaluation of phytochemical characters in Lippia citriodora H.B.K. plantlets affected by propagation methods (micro-propagation and stem cutting) cultivated in different soil type (peat moss and mixture soil). Methods: This study w...

Optimistic replication of data is becoming increasingly popular in distributed systems. However, the performance characteristics of such systems are not well understood. We have developed a simulation to evaluate optimistically replicated file systems in terms of their operating costs (e.g., computing resources) and service quality (e.g., consistency of data perceived by users). The simulation ...

In this paper, vapor pressure for pure compounds is estimated using the Artificial Neural Networks and a simple Group Contribution Method (ANN–GCM). For model comprehensiveness, materials were chosen from various families. Most of materials are from 12 families. Vapor pressure data of 100 compounds is used to train, validate and test the ANN-GCM model. Va...

The colorimetric error depends on the spectrophotometric inaccuracy. In this paper, a ‎new method is introduced for determining the relationship between spectrophotometric ‎error and colorimetric inaccuracy. The error propagation in colorimetric parameter ‎calculation is evaluated using a linear relation between variance of reflectance spectra ‎and CIE tristimulus values. This linear formula ca...