Poly(vinylidene fluoride) (PVDF) nanofibers were prepared via electrospinning process. Several different factors influence on this process and application of experimental design for its optimization is of great importance. The central composite design (CCD) was used for planning and optimizing of the experiments and also, the analysis of variance (ANOVA) was employed for the statistical va...

New pressure drop / flow rate measurements coupled with a previously reported heat transfer database have resulted in new friction factor and heat transfer correlation equations for fan-driven impinging flow through square arrays of cylindrical cross-section pin-fins. The correlation equations include the effect of coolant flow rate, pin-fin density and pinfin height. A comparison with a simila...

OBJECTIVE The aim of this study was to compare flow rates over time and the deviations from the target flow rate of a magnetic resonance imaging contrast agent achieved by an automated injector versus manual injection. MATERIALS AND METHODS In this laboratory study, the magnetic resonance contrast agent gadobutrol was repeatedly injected by an injector and by 10 experienced technologists. Six...

Background: Measuring peak expiratory flow rate has been suggested as an important tool in asthma management by all international guidelines.  Objective: Studies on various populations have shown considerable variations in normal values of peak expiratory flow rate. Since reference standards for Iranian children are not available, the present study was performed to establish these standards. Me...

Flow and congestion control allow the users of a telecommunication network to regulate the traffic that they send into the network in accordance with the quality of service that they require. Flow control may be performed by the network, as is the case in asynchronous transfer mode (ATM) networks (the available bit rate (ABR) transfer capacity), or by the users themselves, as is the case in the...

The growth rate and uniformity of Carbon Nano Tubes (CNTs) based on Chemical Vapor Deposition (CVD) technique is investigated by using a numerical model. In this reactor, inlet gas mixture, including xylene as carbon source and mixture of argon and hydrogen as  carrier gas enters into a horizontal CVD reactor at atmospheric pressure. Based on the gas phase and surface reactions, released carbon...

Tip leakage loss introduces major part of losses of the rotor in axial gas turbines. Therefore, the rotor blade tip has a considerable effect on rotor efficiency. To understand the flow physics of the rotor tip leakage, we solve the flow field for different tip platforms (passive flow control) and by considering coolant tip injection (active flow control). Various blade tip configurations s...

We have recently developed new 3D hydroxyapatite/collagen (50/50 wt%) scaffolds using a biomimetic synthesis approach. The first in vitro tests performed in static culture showed a limited cell colonization and survival inside the scaffolds. The current study evaluated in dynamic culture the scaffold changes and colonization by human immortalized osteoprogenitor STRO-1A cells. The stability of ...

"Etude etiologique de la circulation ra.pide iutra-rena-le"  Le but de l'angiographle renale n'est pas '.seu­lement le controle anatomique de l'organe, une etude physiologique (Hemodynamique) doit toujours etre prise en consideration.  Le temps normal de la circulation intra-renale selon les differents auteurs varie entre 6 a 8, 8 a 10 et 10 a 12 secondes, mais le temps moyen est de 6 a 8 seco...