Crystal Structures and Magnetic Properties of the Co2Mn1−x V x Sb (0 ≤ x ≤ 1) Heusler Compounds

Crystal structure and magnetic properties of the Co₂Mn_1?x V _x Sb (0 ≤ x ≤ 1) Heusler compounds have been studied by X-ray powder diffraction (XRD), magnetometric measurements, and full-potential linearized augmented plane wave (FP–LAPW) method. All compounds crystallize in a cubic Cu₂MnAl-type crystal structure with the space group Fm–3m. The samples for x<0.8 have the Curie temperatures above room temperature, while the Curie temperature is observed at 68 K for the sample with x = 0.8. The saturation magnetization at 5 K decreases linearly with increasing vanadium concentration x. The values of the saturation magnetization obtained by FP–LAPW–local density approximation (LDA) calculations are in better agreement with the experimental results compared with the results obtained by FP–LAPW–generalized gradient approximation (GGA) calculations.     

Discrete-time system modelling in Lp with orthonormal basis functions

In this paper, model sets for linear time-invariant systems spanned by fixed pole orthonormal bases are investigated. The obtained model sets are shown to be complete in L_p(T) (1<p<∞), the Lebesque spaces of functions on the unit circle T, and in C(T), the space of periodic continuous functions on T. The L_p norm error bounds for estimating systems in L_p(T) by the partial sums of the Fourier series formed by the orthonormal functions are computed for the case 1<p<∞. Some inequalities on the mean growth of the Fourier series are also derived. These results have application in estimation and model reduction.     

Detection of early anthracycline-induced cardiotoxicity in childhood cancer with dobutamine stress echocardiography

Although several studies have examined differences in daily blood pressure variability between African-American and Caucasian groups in the United States, little is known about the blood pressure variation of other ethnic groups. This study examined the effects of emotional state, setting, posture, and ethnicity on the ambulatory blood pressure of female health care workers (nurses and nurse's aides) from 2 ethnic groups: Filipino-Americans (N = 38) and Caucasians (N = 22). Ambulatory blood pressure measurements were obtained at 15-min intervals during a typical work day. Participants reported in a diary their setting (work or home), posture, mood, and specific activity at each measurement. The effects of these factors and ethnicity were examined using analysis of variance (ANOVA). The results show that for all subjects blood pressure was higher at work (P < 0.05), while standing (P < 0.05), during reports of negative moods (anxiety, anger, or sadness) (P < 0.05), and while engaging in activities such as interacting with fellow staff members at work and "washing up" at home. However, the Filipino-American women reported negative moods more frequently than their Caucasian counterparts (P < 0.05), had a greater proportion of readings taken while standing at work, and reacted differently than the Caucasian women to some specific activities; for instance, their blood pressure was not elevated when doing household chores. These results suggest that the extent of blood pressure variation in daily life may depend upon cognitive processes which are influenced by the cultural background and emotional state of the individual. They further suggest that ethnicity has an important impact on blood pressure variation.     

Digital bundling

Increasingly, we see that firms offer many items on information-intensive channels and the Internet. Especially with low-marginal-cost digital goods, bundling may be a beneficial strategy. Different bundles may help customers become more discriminating and maximize profits. However, the marketplace evidence provides mixed observation of bundling rigorously pursued. In this study, we provide a general framework to analyze when and how bundling may be beneficial. We compare and contrast the firm and customer characteristics on bundling strategy. We analyze when individual sales can be beneficial. We find that when costs do not increase relative to the bundle valuation, firms find it beneficial to limit the number of bundles offered in the market. A low (zero) marginal cost firm benefits from offering just one big bundle. Such a firm obtains a higher profit compared to a firm that offers many bundles. With high marginal costs, the number of bundles increases with increasing customer valuation and/or heterogeneity. When a firm offers all the bundles, prices and profit increase as customer heterogeneity and valuation increase. When the number of offered items is high, individual sale (unbundling) may be preferred over bundling and bundling becomes an inferior strategy. Interestingly, a firm may benefit from unbundling the items when customers have higher valuations.     

Analyzing the solutions of DEA through information visualization and data mining techniques: SmartDEA framework

Data envelopment analysis (DEA) has proven to be a useful tool for assessing efficiency or productivity of organizations, which is of vital practical importance in managerial decision making. DEA provides a significant amount of information from which analysts and managers derive insights and guidelines to promote their existing performances. Regarding to this fact, effective and methodologic analysis and interpretation of DEA results are very critical. The main objective of this study is then to develop a general decision support system (DSS) framework to analyze the results of basic DEA models. The paper formally shows how the results of DEA models should be structured so that these solutions can be examined and interpreted by analysts through information visualization and data mining techniques effectively. An innovative and convenient DEA solver, SmartDEA, is designed and developed in accordance with the proposed analysis framework. The developed software provides DEA results which are consistent with the framework and are ready-to-analyze with data mining tools, thanks to their specially designed table-based structures. The developed framework is tested and applied in a real world project for benchmarking the vendors of a leading Turkish automotive company. The results show the effectiveness and the efficacy of the proposed framework.     

A dempster-shafer theoretic framework for boosting based ensemble design

Training set resampling based ensemble design techniques are successfully used to reduce the classification errors of the base classifiers. Boosting is one of the techniques used for this purpose where each training set is obtained by drawing samples with replacement from the available training set according to a weighted distribution which is modified for each new classifier to be included in the ensemble. The weighted resampling results in a classifier set, each being accurate in different parts of the input space mainly specified the sample weights. In this study, a dynamic integration of boosting based ensembles is proposed so as to take into account the heterogeneity of the input sets. An evidence-theoretic framework is developed for this purpose so as to take into account the weights and distances of the neighboring training samples in both training and testing boosting based ensembles. The effectiveness of the proposed technique is compared to the AdaBoost algorithm using three different base classifiers.     

A Feasibility study for the Development of a Prospective Compaction Functionality test and the Establishment of a Compaction data BANK

The feasibility for the development of a standard compaction functionality testing method, which is capable of comparing the relative tabletability features of different materials and different lots of the same material with high sensitivity, was tested using an Integrated Compaction Research System. The following factors were optimized: tablet weight, lubrication, tooling, punch displacement profile, pressure range, as well as other pre-, during and post-compaction parameters. The optimized test conditions were found to be as follows: the amount of material to be compacted was calculated to produce a compact with a true volume of 0.25ml; internal lubricant with magnesium stearate at a concentration of 0.5%; standard 10.3mm, flat-faced, round BB tooling; constant punch velocities of 100mm/s and 300mm/s; and a pressure range of 25 to 550MPa. Several model powders which included microcrystalline cellulose, dicalcium phosphate dihydrate, calcium sulfate, dextrates, lactose anhydrous, and spray dried lactose were tested. Using the data generated in this work, the establishment of a compaction data bank that can be utilized as a reference source for tablet formulation studies was also found to be feasible.     

Cleaner water using bimetallic nanoparticle catalysts

Groundwater contaminated by hazardous chlorinated compounds, especially chlorinated ethenes, continues to be a significant environmental problem in industrialized nations. The conventional treatment methods of activated carbon adsorption and air‐stripping successfully remove these compounds by way of transferring them from the water phase into the solid or gas phase. Catalysis is a promising approach to remove chlorinated compounds completely from the environment, by converting them into safer, non‐chlorinated compounds. Palladium‐based materials have been shown to be very effective as hydrodechlorination catalysts for the removal of chlorinated ethenes and other related compounds. However, relatively low catalytic activity and a propensity for deactivation are significant issues that prevent their widespread use in groundwater remediation. Palladium‐on‐gold bimetallic nanoparticles, in contrast, were recently discovered to exhibit superior catalyst activity and improved deactivation resistance. This new type of material is a significant next‐step in the development of a viable hydrodechlorination catalysis technology. Copyright © 2008 Society of Chemical Industry     

Study on swelling of hydrogels (PAAm) at various temperatures by using fluorescence technique

Steady-state fluorescence (SSF) technique was employed for studying swelling of polyacrylamide (PAAm) hydrogels. Disc-shaped gels were prepared by free-radical crosslinking copolymerization of acrylamide (AAm) with N, N′- methylenebis (acrylamide) (BIS) as crosslinker in the presence of ammonium persulfate (APS) as an initiator. Pyranine was introduced as a fluorescence probe. Fluorescence intensity of pyranine was measured during in situ swelling process at various temperatures and it was observed that fluorescence intensity values decreased as swelling is proceeded. Li–Tanaka equation was used to determine the swelling time constants, τ_c and cooperative diffusion coefficients, D _c from intensity, weight and volume variations during the swelling processes. It is observed that swelling time constants, τ_c decreased and diffusion coefficients, D _c increased as the swelling temperature is increased. The swelling activation energies, ΔE were measured from the intensity, weight and volume variations and found to be 10.7, 32.2 and 64.1 kJ mol⁻¹, respectively.