Absolute determination of reaction mechanisms by in situ measurements of reaction intermediates

This paper presents a general methodology to determine reaction mechanisms using in situ measurement of concentration and reaction rate of intermediates. The criteria for testing the validity of a reaction sequence are discussed. An example is given for a heterogeneous catalytic reaction, the decomposition of ozone on manganese oxide. This revised version was published online in August 2006 with corrections to the Cover Date.     

Contact-impact by the pinball algorithm with penalty and Lagrangian methods

Contact-impact algorithms, which are sometimes called slideline algorithms, are a computationally time-consuming part of many explicit simulations of non-linear problems because they involve many branches, so they are not amenable to vectorization, which is essential for speed on supercomputers. The pinball algorithm is a simplified slideline algorithm which is readily vectorized. Its major idea is to embed pinballs in surface elements and to enforce the impenetrability condition only to pinballs. It can be implemented in either a Lagrange multiplier or penalty method. It is shown that, in any Lagrange multiplier method, no iterations are needed to define the contact surface. Examples of solutions and running times are given.     

A functional processor for the relational algebra on a microcomputer

We have built on the U.C.S.D. P-system (running on an IBM Personal Computer) a relational algebra processor, MRDS/FS, which is extremely powerful and which supports a functional syntax for the programmer-user. The relational algebra is provided in the extended operators μ-join, σ-join, project and select. The domain algebra is fully implemented for the first time, giving operations on attributes: arithmetic, logic, comparison and four different categories of aggregation of these. A strictly functional syntax is provided, permitting user-defined functions using the relational and domain algebras as primitive operations. An interactive editor permits the creation, copying and changing of both relations and user-defined functions.     

Approaches to life cycle cost analysis with system availability constraints — A review

Life Cycle Costing (LCC) has attracted growing attention as a tool for choosing between designs of operational facilities and between modes of operating them. Since failures, repairs, and replacements are major contributors to life cycle costs, it has become apparent that eliability, vailability, and aintainability (RAM) modeling techniques should be incorporated into LCC modeling. A variety of approaches to combining these techniques have appeared in the technical literature. This paper is a state-of-the art review of the literature pertaining to availability-based life cycle cost analysis.     

Testing the common wisdom: The social content of video pornography.

Analyzed 150 sexually oriented home videos with respect to their sexual, aggressive, and sexually aggressive content. While the primary focus was on sexually explicit, "triple-X" videos, a number of more mainstream "adult" videos were also analyzed for comparison. As anticipated, triple-X videos depicted sexual content significantly more explicitly than did adult videos. Contrary to expectations, however, it was the adult videos that contained significantly more aggressive and sexually aggressive content and that depicted this violence with significantly greater severity. (French abstract) (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Biometric Menagerie

It is commonly accepted that users of a biometric system may have differing degrees of accuracy within the system. Some people may have trouble authenticating, while others may be particularly vulnerable to impersonation. Goats, wolves, and lambs are labels commonly applied to these problem users. These user types are defined in terms of verification performance when users are matched against themselves (goats) or when matched against others (lambs and wolves). The relationship between a user's genuine and impostor match results suggests four new user groups: worms, doves, chameleons, and phantoms. We establish formal definitions for these animals and a statistical test for their existence. A thorough investigation is conducted using a broad range of biometric modalities, including 2D and 3D faces, fingerprints, iris, speech, and keystroke dynamics. Patterns that emerge from the results expose novel, important, and encouraging insights into the nature of biometric match results. A new framework for the evaluation of biometric systems based on the biometric menagerie, as opposed to collective statistics, is proposed.     

Recent improvements in SPH modeling of hypervelocity impact

Four improvements to Smoothed Particle Hydrodynamics which enhance its ability to simulate hypervelocity impact are discussed and applied to the impact fracture of a steel cube on an aluminum plate at 2.2 km/s.     

Home relaxation practice in hypertension treatment: Objective assessment and compliance induction.

50 Ss (mean age 51.1 yrs) with essential hypertension were randomly assigned to 1 of 4 conditions: individualized relaxation, group relaxation (GR), GR plus contingency contracting (CC) for home practice, or a waiting list. Treated Ss were given tape players and relaxation tapes and were instructed to practice daily for 10 wks. Unknown to the Ss, the tape players had a concealed capacity to electronically monitor the amount of relaxation practice. All relaxation conditions showed significantly greater reductions in both systolic and diastolic blood pressure than waiting-list controls but did not differ from each other. Monitored relaxation predicted systolic but not diastolic changes. Self-reports exceeded monitored practice by 91%, and only 32% of the Ss averaged 1 practice/day. GR plus CC Ss showed the lowest rate of practice across most weeks. Rated self-efficacy, age, and pretreatment expectations of benefit were positively correlated with relaxation compliance. Data support the use of relaxation for hypertension but suggest that noncompliance is common in both individual and group relaxation training. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An experimental approach for the analysis of early-age behaviour of high-performance concrete structures under restrained shrinkage

This paper presents a systematic approach for the experimental testing and analysis of the early-age thermo-mechanical behaviour of large prismatic high-performance concrete specimens under restrained autogenous shrinkage and realistic temperature conditions. The loading system can apply a partial degree of restraint in order to enable the characterisation of high-performance concrete specimens without premature termination of the test in case of significant restrained shrinkage. The instrumentation system can measure the strains and other parameters from the setting time with high accuracy and reliability. The analysis method takes into account the temperature effects on the measured properties and provides equations to determine the time-evolution of shrinkage, thermal expansion, stiffness and creep of the concrete. Results from the testing of 200 × 200 × 1000 mm specimens made with a 0.34 water-cement ratio concrete are presented, analysed and discussed in the paper to demonstrate the application of the proposed approach.