Abstract Aging is associated with an accumulation of T cells functionally hyporesponsive to the effects mitogens such as concanavalin A. Recent studies in mice and humans have identified surface markers useful for distinguishing antigen‐stimulated memory from virgin cells. In mice, within CD8 + cell population been shown express relatively high levels glycoprotein Pgp‐1. On theory that aging might diminish supply thymic emigrants without compromising production cells, we examined proportion...

MARKET structure has long been considered as a prime determinant of industrial performance. Firms in the search for profit restrict output, raise price, and earn supernormal if market which they find themselves permits. This article reports an empirical attempt to relate performance with U.S. manufacturing sector: measures rates are regressed on structure. The primary variable is rate, computed two ways: income after taxes plus interest paid borrowed capital percentage total assets, net...

Seven-wire prestressing strands are commonly used to pretension concrete bridge members. While the industry standard is 12.7-mm (0.5-in.) or 15.2-mm (0.6-in.) diameter strand, interest in developing greater pretensioning forces has resulted proposed use of 17.8-mm (0.7-in.) strands. This paper reports an experimental program aimed at characterizing bond properties seven-wire strand and contrasting these with 9.5-mm (3/8-in.), (1/2-in.), (−0.6-in) The geometric material reported, evaluation...

High-strength steel reinforcement provides various benefits to the concrete construction industry, including a more efficient use of high-performance concrete, reduction reinforcing bar congestion, and materials savings. Prior 2013 interim revisions AASHTO LRFD Bridge Design Specifications, value yield strength used in design was limited being no greater than 517 MPa (exceptions were permitted with owner approval for cases less 414 MPa). In 2007, National Cooperative Highway Research Program...

Adjacent precast, prestressed box girder bridges are widely used in the United States, but shear keys between girders tend to crack and leak. Three different key configurations were studied, i.e., a current detail where is approximately 10 in. (250 mm) from top of grouted with non-shrink grout, this same epoxy rather than proposed mid-depth keyway grout. The tests conducted on full scale, four-beam assembly which represented part bridge. results showed that currently cracks due thermal...

The need for partial discharge (corona) measurements at very low frequencies is explained, and the results of tests on epoxy resin polyethylene samples are given frequency range 0.1 Hz to 50 Hz. As no suitable commercial generator was available, a new type low-frequency low-noise has been developed. detection system includes pulse discrimination eliminating unwanted pulses from outside test component. This particularly useful when measuring discharges in short length cross-linked cable...

Subjects' extrapolations of a piecewise constant-velocity trajectory and constant-acceleration were mapped out over sequence trials that required only button-press response. Without any performance feedback, subjects' both trajectories approximated an acceleration segment followed by segment. With the approached optimal performance. Subsequent withdrawal feedback shifted entire extrapolated trajectory. These feedback-related changes in can be interpreted as two parameters cognitive...

Summary Vacuum-insulated tubing (VIT) has been used successfully to mitigate the potentially harmful effects of annular pressure buildup (APB). In a recent deepwater installation, subject well had lost alternate APB mitigation capability through series events. VIT was then chosen as only viable technology. A common design companion is gelled brine, decrease natural convection driven by heat loss around connections. There are, however, several drawbacks indiscriminate use brine: Tight...

Abstract The problem of designing an optimal (n — m)-order Luenberger observer for nth-order time-invariant linear system with m (m <n) outputs is considered. performance functional this the expected value well-known quadratic regulator measure. It assumed that only mean and covariance initial state are known. structure fixed but parameter values, including feedback gain, left free to be specified via specific control problem. Necessary conditions optimality derived a design algorithm...

The new merger guidelines, issued on June 14, 1982, by the Department of Justice, shift from using familiar four-firm concentration ratio to unfamiliar Herfindahl-Hirschman Index (HHI) as a measure or index market structure. This article explains and interprets HHI, improve its understanding members antitrust bar. Successive sections: 1. define HHI summed, squared shares individual firms in percentage form, with an explicit link dispersion variability number market, hypothetical examples; 2....

Lean production techniques developed by Toyota Motor Corporation have been widely applied in the manufacturing sector to reduce waste, ensure just-in-time delivery, create effective value streams, and continuous improvement. Over last two decades, significant efforts made develop theoretical foundation practical tools implement these construction process. The process is similar production, that it involves assembly of raw materials into a product. design process, on other hand, conversion...

High-power electromagnetic pulses are of importance in a variety applications such as transient radar and particle accelerators when investigating the effect strong radio-frequency impulses on electronic systems. With all these possibilities mind, compact portable source has been developed by Plasma Pulsed Power Group, Loughborough University, U.K., collaboration with Defense Science Technology Laboratory, U.K. The is based pulsed resonant Tesla transformer that produces nanosecond rise-time...

The paper describes a very-low-frequency (VLF) high-voltage test facility and includes the results of partial-discharge (corona) measurements undertaken on samples electrical machine insulation. were energized by means generator, capable producing alternating Voltages from 0.1 Hz up to power frequency. In order eliminate spurious signals, using pulse discrimination system (PDS). output PDS was fed height analyzer which enabled distribution discharge magnitudes be displayed. This information...