Comparison Of Stability Research Articles

Advanced laminated antiferromagnetically coupled recording media with high thermal stability

A layered structure to improve the antiferromagnetic exchange coupling constant (J) in laminated antiferromagnetically coupled (LAC) media is proposed. This structure has a much larger thermal stability in comparison to simple LAC structures. It also improves the coercivity and decreases the remnant moment-thickness product to achieve a high resolution and a low pulse width. The recording measurements indicate that this structure has a slightly larger noise than the simple LAC structures. However, its overall signal-to-noise ratio (SNR) is comparable to that of the simple LAC structures. High SNR and much higher thermal stability make this structure suitable for ultrahigh areal densities.

Stability preserving mappings for stochastic dynamical systems

We first formulate a general model for stochastic dynamical systems that is suitable in the stability analysis of invariant sets. This model is sufficiently general to include as special cases most of the stochastic systems considered in the literature. We then adapt several existing stability concepts to this model and we introduce the notion of stability preserving mapping of stochastic dynamical systems. Next, we establish a result which ensures that a function is a stability preserving mapping, and we use this result in proving a comparison stability theorem for general stochastic dynamical systems. We apply the comparison stability theorem in the stability analysis of dynamical systems determined by Ito differential equations.

Urease immobilized on nylon: preparation and properties

Urease (EC 3.5.1.5) was covalently attached through glutaraldehyde to partially hydrolysed nylon 6/6 tubes. The highest activity of immobilized enzyme was obtained at 65 °C and pH 6.5, while the optimum temperature for free urease was found to be 25 °C. Immobilized urease showed an improved thermal stability in comparison to free urease. It retained 76% of the original activity after 60 days when stored at 4 °C and 78% of the activity after 5 repeated uses.

Solving dilemmas by computer or counselor.

Results of studies in which either a human counselor or a computer was used to solve personal dilemmas are compared. Subjects were 415 undergraduate students. To increase stability of comparisons the counselor groups are aggregated as are the computer groups and the control groups. Comparison tests are then made among the aggregated groups. Two types of comparisons are made, significance tests and comparisons for size of effects. Computer counseling was as effective as standard counseling for dilemma-type problems. Computer counseling was significantly more effective than the control condition as was standard counseling. Comparisons of size of effect indicate that the average person in the computer groups was moved to the 51st percentile of the counselor groups and to the 78th percentile of the control groups. Size of effect for general psychotherapy and counseling indicate movement to the 75th percentile of the control groups. Thus, the effect of computer counseling resembles the over-all effect for general therapy. Future comparison of computer and counselor methods, effectiveness, and reactions is discussed.