The traY gene of the Escherichia coli F plasmid has been shown by genetic studies (R. Everett and N. Willetts, J. Mol. Biol. 136:129-150, 1980) to be involved in the site-specific nicking reaction at oriT required for the initiation of DNA transfer during bacterial conjugation. In order to assign a biochemical function to TraY protein, the traY gene was cloned in a plasmid vector which utilizes...

Many test handlers process semiconductor devices in trays which must be rapidly heated or cooled by a forced air flow to a desired test temperature and then back to ambient temperature. This paper describes a new design feature for testhandler tray that significantly increases the rate of convective heat transfer to the tray and the devices in the tray. The improved tray incorporates lateral ri...

objectives: the purpose of this study was to compare the accuracy of implant position transfer and surface detail reproduction using two impression techniques and materials. materials and methods: a metal model with two implants and three grooves of 0.25, 0.50 and 0.75 mm in depth on the flat superior surface of a die was fabricated. ten regular-body polyether (pe) and 10 regular-body polyvinyl...

OBJECTIVES The purpose of this study was to compare the accuracy of implant position transfer and surface detail reproduction using two impression techniques and materials. MATERIALS AND METHODS A metal model with two implants and three grooves of 0.25, 0.50 and 0.75 mm in depth on the flat superior surface of a die was fabricated. Ten regular-body polyether (PE) and 10 regular-body polyvinyl...

PURPOSE The aim of this in vitro study was to compare the accuracy of two different impression techniques for the All-on-Four implant therapy protocol. MATERIALS AND METHODS An acrylic resin analog for an edentulous maxilla with four internal connection implants (Replace Select, Nobel Biocare) was fabricated according to the All-on-Four protocol. A total of 40 impressions were made with diffe...

In the present study, experimental investigations about the hydrodynamics of the conical cap tray (ConCap tray) have been carried out. The ConCap tray is an innovative and novel type of cap trays. The effect of the different weir height (2.5, 5 and 7 cm) on the weeping, entrainment and the total pressure drop for the ConCap tray was measured, compared and correlated. The hydraulic experiments w...

INTRODUCTION Since almost all industrial scale columns are round, the side downcomers present unique challenges for liquid distribution both to and from the downcomers. Liquid leaving these downcomers needs to spread outwardly, away from the flow path centerline, in order to evenly feed the diverging tray active area. Also, one of the characteristics of side downcomers is that they naturally te...

From a design and hydraulic standpoint, trays are relatively complex distillation internals. In the ongoing search for higher performance trays, one first must understand the hydraulic and mass transfer aspects of the tray operation such as entrainment, downcomer flooding, and vapor liquid contact. When this is well understood, then various aspects of the deck and/or downcomer designs can more ...