Temper embrittlement response and toughness of a rare earth treated Ni-Cr-Mo steel

Embrittled and unembrittled transverse Charpy V-notch impact energies are compared for three commercially-produced Ni-Cr-Mo steel plates. Two of the plates were made from ingots which had been treated by the addition of mischmetal during teeming. Although the mischmetal additions were found to be ineffective in altering the susceptibility of the steel to temper embrittlement, they have a significant effect on improving the transverse toughness. It was concluded that rare earth additions, because of their beneficial effect on toughness, may provide a convenient means of coping with the problem of temper embrittlement.     

Potentiostatic cleaning and conditioning of the cathodes used in electrodeposition cells

A new technique for the automatically controlled removal of residual electrodeposits from the cathode is presented. The discussion is based on theoretical electrode processes and laboratory experiments. The technique essentially consists of an industrial process potential controller which maintains the cathode in a noncorroding state while forcing the removal of the more electroactive residual metal deposits. The technique is both time and labor saving, and eliminates the additional need for cathode treating chemicals.     

A numerical pattern synthesis algorithm for arrays

A numerical technique for pattern synthesis in arrays is presented. For a given set of elements, the technique allows one to find a set of array coefficients that steer the main beam in a given direction and yield sidelobes meeting a specified criterion, if such a set of array coefficients exists. If the pattern specifications cannot be met with the given elements, the algorithm finds the best attainable pattern. The advantage of this technique is that it can be used with an arbitrary set of array elements. Different elements in the array can have different element patterns, and the array can have arbitrary nonuniform spacing between elements. The synthesis technique is based on adaptive array theory. The given array elements are assumed to be used as the elements of an adaptive array. The main beam is pointed in the proper direction by choosing the steering vector for that direction, and the sidelobes are controlled by introducing a large number of interfering signals at many angles throughout the sidelobe region. The algorithm iterates on the interference powers until a suitable pattern is obtained     

Is cost accounting the answer? Comparison of two behaviorally based methods for estimating the standard deviation of job performance in dollars with a cost-accounting-based approach.

Accurate estimation of the standard deviation of job performance in dollars (SDy) can improve the precision of utility estimates of expected payoffs from personnel programs. The purpose of this study was to compare directly the estimates of SDy obtained using a cost-accounting-based estimate of SDy, the Global Estimation Model, and the CREPID procedure. The study was conducted in a large, soft-drink bottling company. Each method for estimating SDy was applied to the job classification, route salesman, producing three independent estimates of SDy. These estimates were tested for significant differences. Results indicated that the Global Estimation Model estimate and the cost-accounting-based estimate were not significantly different, whereas the estimate produced by the CREPID procedure was significantly smaller. Limitations of the cost-accounting-based estimate are identified and results are discussed in terms of their implications for the theory and practice of utility analysis in organizations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental study of fire-resistant steel H-columns at elevated temperature

This paper presents the experimental studies of axially loaded fire-resistant steel columns under elevated temperature. With the advancement of metal production, fire-resistant steel with enhanced mechanical properties at elevated temperatures has been developed recently. However, extensive research work is needed in order for the application of fire-resistant steel in building structures. In this study, a series of fire-resistant steel columns was loaded to their ultimate states at specified temperature. The effects of width-thickness ratios, slenderness ratios and residual stress on the performance of fire-resistant steel H-columns are examined. Based on this study, it is found that the section property of fire-resistant H-columns should be at least a non-compact section in order to prevent local buckling. Column strength is sensitive to slenderness ratio at elevated temperature. The strength of a slender column decreased sharply especially for temperatures above 600 ^°C. It is also found that the failure mode of steel columns changed from inelastic global buckling at room temperature to local buckling at elevated temperature, due to the release of residual stress in fire. An analytical model is proposed which is able to predict the behavior of fire-resistant steel H-columns under elevated temperature. Design guidelines are also proposed for the design of fire-resistant steel columns in fire conditions.     

Two-level control strategy of an eight link biped walking model

This paper presents an adaptive two-level control strategy for a biped walking model and demonstrates its performance in a wide range of walking modes with considerably diverse model and control parameter settings. Proposed control strategy inherits a push off that resembles considerably to forceful extension of the trailing leg during push off in human locomotion and represents a very important source of forward propulsion. Extensive simulations have shown that adjustments in the push off related parameter on higher between-step control level after each step enable evolution of various walking modes of the biped walker at selected walking speeds and distinctive gait patterns. It also allows us to investigate the changes in gait kinematics and kinetics of the biped walking model due to changes in gait velocity, torso inclination and propulsion distribution profiles.