Atomic Force Microscope Cantilever Flexural Stiffness Calibration: Toward a Standard Traceable Method

The evolution of the atomic force microscope into a useful tool for measuring mechanical properties of surfaces at the nanoscale has spurred the need for more precise and accurate methods for calibrating the spring constants of test cantilevers. Groups within international standards organizations such as the International Organization for Standardization and the Versailles Project on Advanced Materials and Standards (VAMAS) are conducting studies to determine which methods are best suited for these calibrations and to try to improve the reproducibility and accuracy of these measurements among different laboratories. This paper expands on a recent mini round robin within VAMAS Technical Working Area 29 to measure the spring constant of a single batch of triangular silicon nitride cantilevers sent to three international collaborators. Calibration techniques included reference cantilever, added mass, and two forms of thermal methods. Results are compared to measurements traceable to the International System of Units provided by an electrostatic force balance. A series of guidelines are also discussed for procedures that can improve the running of round robins in atomic force microscopy.     

Enabling multi-use, multi-tool models of manufacturing systems through an experimental frame expert system

A significant shortcoming of traditional modeling methodologies is the limited access they provide for decision-makers who are not modeling specialists. This paper presents an expert system approach to address this shortcoming. An expert system called the experimental frame expert system (EFES) was developed for this purpose within an advanced modeling environment for manufacturing systems. EFES reduces the dependence upon modeling specialists, and thus, makes models, both analytical and simulation, more accessible to decision-makers. This is accomplished by using two knowledge bases, one related to the manufacturing system specific symptoms and problems, and the other to system analysis and optimization tools. This paper presents the dissertation research effort that led to development of these two knowledge bases as well as the EFES framework within the advanced modeling environment.     

Distributed optical fibre Raman temperature sensor using a semiconductor light source and detector

The letter reports on the first experimental measurements of the temperature distribution along silica-based optical fibres using a semiconductor laser source and an avalanche photodiode detector. Previous results by the same authors demonstrated the first use of the Raman scattering technique, but used a less practical ion laser source and a photomultiplier detector.     

COMPARISON OF HYDRODYNAMIC AND MASS TRANSFER PERFORMANCE OF SMR,RASCHIG RING AND PULSED PERFORATED PLATE COLUMN

ABSTRACT

Cyanex 923 has been proposed as an extractant for the removal of sulphuric acid from copper tank house bleed streams. This process requires many stages and so is ideal for column operation. This paper presents a comparison between three types of column for this service. The new SMR packing marketed by Glitsch is the first packing developed specifically for liquid-liquid extraction service and is compared with a column packed with Raschig rings and a pulsed perforated plate column.     

DROPLET COALESCENCE AND BREAKAGE RATES IN LIQUID EXTRACTION COLUMNS

Abstract

A review is given of recent work on the measurement of droplet coalescence and breakage rates in a packed and a pulsed plate extraction column using a newly developed colorimetric technique. The results, which were interpreted in terms of second order coalescence and first order breakage rate constants, showed that the droplet interaction rates are considerably lower in the pulsed column. The rate constants can also be used to predict accurately the steady state droplet size distribution, and to study theoretically the effect of droplet coalescence and breakage on mass transfer rate. Deficiencies in the available mass transfer coefficient data for droplets, both individual and in “swarms”, are pointed out.     

Greater rate of decline in maximal aerobic capacity with age in physically active vs. sedentary healthy women

Using a meta-analytic approach, we recently reported that the rate of decline in maximal oxygen uptake (VO2 max) with age in healthy women is greatest in the most physically active and smallest in the least active when expressed in milliliters per kilogram per minute per decade. We tested this hypothesis prospectively under well-controlled laboratory conditions by studying 156 healthy, nonobese women (age 20-75 yr): 84 endurance-trained runners (ET) and 72 sedentary subjects (S). ET were matched across the age range for age-adjusted 10-km running performance. Body mass was positively related with age in S but not in ET. Fat-free mass was not different with age in ET or S. Maximal respiratory exchange ratio and rating of perceived exertion were similar across age in ET and S, suggesting equivalent voluntary maximal efforts. There was a significant but modest decline in running mileage, frequency, and speed with advancing age in ET. VO2 max (ml . kg-1 . min-1) was inversely related to age (P < 0.001) in ET (r = -0.82) and S (r = -0.71) and was higher at any age in ET. Consistent with our meta-analysic findings, the absolute rate of decline in VO2 max was greater in ET (-5.7 ml . kg-1 . min-1 . decade-1) compared with S (-3.2 ml . kg-1 . min-1 . decade-1; P < 0. 01), but the relative (%) rate of decline was similar (-9.7 vs -9. 1%/decade; not significant). The greater absolute rate of decline in VO2 max in ET compared with S was not associated with a greater rate of decline in maximal heart rate (-5.6 vs. -6.2 beats . min-1 . decade-1), nor was it related to training factors. The present cross-sectional findings provide additional evidence that the absolute, but not the relative, rate of decline in maximal aerobic capacity with age may be greater in highly physically active women compared with their sedentary healthy peers. This difference does not appear to be related to age-associated changes in maximal heart rate, body composition, or training factors.     

Generativity and moral development as predictors of value-socialization narratives for young persons across the adult life span: From lessons learned to stories shared.

Little research so far has examined storytelling as a channel of value socialization. In the present study, 129 adults from 3 age groups (18–26, 28–50, 60–75) were asked to tell stories for adolescents about 2 of their past value-learning experiences. Generative concern (D. P. McAdams & E. de St. Aubin, 1992) and moral reasoning stage level were also assessed. Stronger generative concern was predictive of a greater sense of having learned important lessons from these past events, of stronger adult value socialization investment, and of more engaging narratives for adolescents as judged by a panel of uninstructed raters. Higher levels of moral reasoning were positively related to generative concern and to a stronger sense of past lessons learned. Generativity appears important to the project of value socialization across the adult life span. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Numerical Modeling of Bolted Lap Joint Behavior

Nonlinear finite-element models are developed that predict the load-elongation behavior of conical-head bolted lap joints, and the load-elongation predictions are compared with experimental test data. The study is conducted for several panel thicknesses with three fastener sizes and three panel materials. The model load-elongation predictions are in excellent agreement with experimental test data. Model parameters, such as part discretization, material model selection, sliding interface friction coefficients, and convergence tolerances, are discussed. A means of inducing clamp in the joint is also developed. The results show that nonlinear finite-element analysis may reliably predict the behavior of conical-head bolted joints.     

3G Trials and Developments

This paper summarises the many activities that formed a vigorous and innovative phase of understanding 3rd generation systems and their potential service/product offering.Experience from the introduction of 2nd generation GSM systems showed that, even though based upon strong standards, real hands-on development to validate the design activities was essential for both a workable standard and a smooth and successful service deployment. Trials activities are used to overcome the lack of validation and to bring innovation through integration of capabilities and devices — they consist of two areas. Firstly, a number of test radio systems were examined and used in the validation of network planning tools plus measurement or real throughput figures, and, secondly, some service scenarios were developed and implemented on an all-IP network to demonstrate that IP can deliver a marketable services level. The interaction with wireless systems and the impact of that on the application were also examined.