Using Gap Analysis to Improve System Acceptance

The authors describe a user/customer needs gap model that can be used to develop a balanced approach to managing the gaps between business customer and end-user needs for new systems and the solutions that are deployed.     

Impedance spectroscopy analysis of the influence of superplasticizers on steel corrosion in OPC mortars

The influence of commercial superplasticizers on the mechanism of corrosion of steel reinforcements embedded in concrete has been investigated by the impedance spectroscopy technique using Portland cement mortars with and without added chloride. Significant differences in spectra in the range 0.03–65 kHz are shown to occur as a function of composition and moist cure duration up to 240 days. The impedance spectra in the early stages indicate surface layer formation, attributed to superplasticizer adsorption to the surface of reinforcing rods. The adsorbed surface layer persists only within the initial 90 day cure. At longer ages, the superplasticizer layer breaks down. However, calcium lignosulphonate gives markedly lowered corrosion rates in the presence of chloride; the other plasticizers corrode at essentially the same rate as the control without plasticizer.     

Distribution of conjugates of alkylphenols in milk from different ruminant species

Conjugated alkyphenols in milk constitute a reservoir for species-related alkylphenols in dairy products. The distributions of conjugated alkylphenols between different conjugation pathways (sulfation, phosphorylation, and glucuronidation) were determined in cows', sheep's, and goats' milk. Species-related p- and m-cresols and 3- and 4-ethylphenols were found to be mostly conjugated with sulfate with minor amounts associated with phosphate and glucuronide conjugates in all milks. Similar distributions were observed for alkylphenols in the urine and milk from the same ewe. Phenol was present in minor amounts distributed sporadically between different conjugates in the milks. Sulfate-conjugated phenol was not detected in the ewe's urine, which included equal amounts of glucuronide and phosphate conjugates. The amounts of alkylphenols were different in sheep's milk from different sources suggesting that there were effects of feed, breed, and individual animal variation on the metabolism of alkylphenols.     

Contour-based object tracking with occlusion handling in video acquired using mobile cameras

We propose a tracking method which tracks the complete object regions, adapts to changing visual features, and handles occlusions. Tracking is achieved by evolving the contour from frame to frame by minimizing some energy functional evaluated in the contour vicinity defined by a band. Our approach has two major components related to the visual features and the object shape. Visual features (color, texture) are modeled by semiparametric models and are fused using independent opinion polling. Shape priors consist of shape level sets and are used to recover the missing object regions during occlusion. We demonstrate the performance of our method in real sequences with and without object occlusions.     

Effect of microbial transglutaminase and sodium caseinate on quality of chicken döner kebab

The effect of microbial transglutaminase (MTGase) and sodium caseinate on the quality of chicken d?ner kebab was investigated. Yield, color, pH, SDS-polyacrylamide gel electrophoresis (SDS-PAGE), texture, and sensory evaluations were measured. The results of SDS-PAGE showed that addition of MTGase with or without sodium caseinate created cross-linking between meat proteins. Texture measurements indicated that the effect of the enzyme on binding properties of chicken meat is more effective if it is used with sodium caseinate (P<0.05). Sensory evaluation was not significantly different statistically among treatments.     

(Reactive) Templated Grain Growth of Textured Sodium Bismuth Titanate (Na1/2Bi1/2TiO3-BaTiO3) Ceramics—II Dielectric and Piezoelectric Properties

(Na_1/2Bi_1/2)TiO₃-BaTiO₃ (<6.5% BaTiO₃) ceramics with <001>_pc orientation were fabricated by Templated Grain Growth (TGG) or Reactive Templated Grain Growth (RTGG) using tabular SrTiO₃ template particles. The maximum electrically-induced strain was 0.26% at 70 kV/cm. d₃₃ coefficients over 500 pC/N were obtained for highly textured samples (f 90%) when driven at high electric fields. Under these conditions, the materials show considerable hysteresis in the strain—field response, even after poling. Berlincourt piezoelectric coefficients for the same samples gave d₃₃ of 200 pC/N.     

Contraction of experimental skin flaps

BACKGROUND AND PURPOSE: Some types of radiation therapy have been associated with an increased risk of cardiac mortality and morbidity in patients with early-stage breast cancer. A relationship has been observed between cardiac radiation dose-volume and the level of excess risk of cardiac mortality. However, relatively few data are available on the morbidity from myocardial infarction associated with adjuvant radiotherapy. PATIENTS AND METHODS: From 1971 to 1976, a total of 960 patients with operable breast cancer were randomly allocated to preoperative radiation therapy, postoperative radiation therapy or to surgery alone. A previous analysis of the cardiac dose-volumes with the treatment techniques used in the trial indicated that the irradiated patients could roughly be divided into three groups. Information on the number of myocardial infarctions was obtained through computerized record linkage with a population-based registry of myocardial infarctions in Stockholm County. Information on cause-specific mortality was obtained from the Swedish Cause-of-Death Registry. The median follow-up was 20 years (range 17-23 years). RESULTS: A total of 58 patients developed an acute myocardial infarction during the period of follow-up. The number of myocardial infarction cases was not significantly different between the three treatment groups. When analyzed according to estimated cardiac radiation dose-volumes, patients in the highest dose-volume subgroup exhibited a hazard of myocardial infarction of 1.3 (95% CI 0.7-2.6) relative to that of the surgical controls, whereas the corresponding relative hazard for the intermediate and low dose-volume subgroups was below unity. Data on death due to cardiovascular disease showed that patients in the high dose-volume group exhibited a hazard of 2.0 (95% CI 1.0-3.9, P = 0.04) relative to that of the surgical controls. Concerning death due to ischemic heart disease, the relative hazard for the same subgroup was 2.5 (95% CI 1.1-5.7, P = 0.03). The difference between the groups was established after 4-5 years. The cumulative incidence curves continued to diverge up to about 10-12 years. No further divergence appeared after 12 years, but the number of events was low. CONCLUSIONS: This analysis confirms and extends previous results from the trial. Cardiac mortality was positively correlated with the cardiac dose-volume. Patients receiving high dose-volumes exhibited an increased mortality of ischemic heart disease, but not of myocardial infarction, which implies another mechanism, e.g. radiation-induced microvascular damage to the heart.     

Time domain adaptive integral method for surface integral equations

An efficient marching-on-in-time (MOT) scheme is presented for solving electric, magnetic, and combined field integral equations pertinent to the analysis of transient electromagnetic scattering from perfectly conducting surfaces residing in an unbounded homogenous medium. The proposed scheme is the extension of the frequency-domain adaptive integral/pre-corrected fast-Fourier transform (FFT) method to the time domain. Fields on the scatterer that are produced by space-time sources residing on its surface are computed: 1) by locally projecting, for each time step, all sources onto a uniform auxiliary grid that encases the scatterer; 2) by computing everywhere on this grid the transient fields produced by the resulting auxiliary sources via global, multilevel/blocked, space-time FFTs; 3) by locally interpolating these fields back onto the scatterer surface. As this procedure is inaccurate when source and observer points reside close to each other; and 4) near fields are computed classically, albeit (pre-)corrected, for errors introduced through the use of global FFTs. The proposed scheme has a computational complexity and memory requirement of O(N/sub t/N/sub s/log/sup 2/N/sub s/) and O(N/sub s//sup 3/2/) when applied to quasiplanar structures, and of O(N/sub t/N/sub s//sup 3/2/log/sup 2/N/sub s/) and O(N/sub s//sup 2/) when used to analyze scattering from general surfaces. Here, N/sub s/ and N/sub t/ denote the number of spatial and temporal degrees of freedom of the surface current density. These computational cost and memory requirements are contrasted to those of classical MOT solvers, which scale as O(N/sub t/N/sub s//sup 2/) and O(N/sub s//sup 2/), respectively. A parallel implementation of the scheme on a distributed-memory computer cluster that uses the message-passing interface is described. Simulation results demonstrate the accuracy, efficiency, and the parallel performance of the implementation.     

Application of proximal isovelocity surface area method to determine prosthetic mitral valve area

BACKGROUND: In this study, we investigated the accuracy of orifice area determination of the prosthetic valve (Biocor) by using proximal isovelocity surface area method (PISA). Thirty-two patients (26 women, 6 men; mean age 44 +/- 8.1 years) were studied. Eleven patients were in normal sinus rhythm and the rest were in atrial fibrillation. Associated valvular lesions were mild aortic regurgitation in 12 patients and moderate tricuspid regurgitation in 19 patients. Sizes of prosthetic valves were 27 to 31, and implantation duration was 4 to 8 years. METHODS AND RESULTS: We analyzed the flow convergence zone proximal to the valve orifice with the concept of a hemispheric model. Mitral valve area (MVA) calculation was formulated by MVA = 2pi r2 x Va/Vm x (Vm/Vm-Va), where Vm is the maximal mitral velocity and Vm/Vm - Va is a correction factor to account for flattening of isotachs near the prosthetic orifice. MVA calculations by PISA were compared with pressure half-time (PHT), continuity equation (CONT), and color flow area (CFA) methods. Mitral valve areas were 2.17 +/- 0.17 cm2, 2.22 +/- 0.21 cm2, 2.19 +/- 0.22 cm2, and 2.16 +/- 0.17 cm2 in PISA, CFA, PHT, and CONT methods, respectively. Values in the comparison of MVA measurements by different methods were PISA vs PHT, r =.86; PISA vs CFA, r =.77; and PISA vs CONT, r =.89. CONCLUSIONS: The PISA method gives reliable estimates of large orifices such as prosthetic valves. Although the best correlation was seen with the CONT method, results of this study also confirmed that the PISA method can be applied with reasonable accuracy.