Machine learning and IoT-based cardiac arrhythmia diagnosis using statistical and dynamic features of ECG

The Journal of Supercomputing - Cardiac arrhythmia is a life-threatening disease which causes severe health problems in patients. A timely diagnosis of arrhythmia diseases will be useful to save...     

Effect of Uncertainty in Failure Rates on Memory System Reliability

This paper investigates the effect of uncertainty in chip failure rates on memory system reliability. It is shown, using real data on memory failures, that the dispersion in failure rates can be as large as 80%. An important consequence is to increase the unreliability of a memory system by up to 65%. Two simple models are proposed to evaluate the variability in memory reliability. The first is a worst case estimate and the second is a probabilistic model which needs only the mean and the standard deviation of the chip failure rate. With high failure rates, the maximum uncertainty in reliability occurs in the early system lifetime; with low failure rates, this effect is reversed.     

Microwave absorption,reflection and EMI shielding of PU–PANI composite

In order to allow electronic components to coexist without harmful electromagnetic interference (EMI) it is necessary to develop new shielding and absorbing materials with high performance and a large operating frequency band. Conducting polymer composites have been found to be suitable for EMI shielding and for the dissipation of electrostatic charge. In the present study polyaniline–polyurethane (PANI–PU) composite was considered for these applications. The microwave absorption, microwave reflection and EMI shielding properties of PANI–PU composite is evaluated both at S-band and X-band frequencies. The material is found to have good microwave absorption and is a potential candidate for EMI shielding applications.     

Effect of oilseed protein concentrates and exogenous amino acids on the dialysability of iron and zinc

Iron deficiency anaemia and zinc deficiency have been persistent public health problems worldwide. Both deficiencies are attributed to poor bioavailability of minerals. The investigation was undertaken to study the effect of oilseed protein concentrates and exogenous amino acids on the dialysability of iron and zinc. Corn flour matrices with 10–20 g protein/100 g were formulated using groundnut and sesame protein concentrates. Dialysability of iron and zinc in natural and mineral fortified matrices was analysed. The effect of exogenous cysteine, histidine, glycine and lysine on mineral dialysability was analysed in groundnut and sesame protein concentrates. Dialysability of iron was enhanced with increasing protein concentration in matrices with groundnut protein but decreased in matrices with sesame protein. Dialysability of zinc increased with increasing protein concentration with both the protein concentrates. Among the amino acids, histidine enhanced dialysability of iron in natural groundnut and sesame protein concentrates, glycine in fortified groundnut and lysine in fortified sesame protein concentrates to a considerable extent. Dialysability of zinc was enhanced in natural groundnut, natural and fortified sesame protein concentrates by all amino acids. Amino acids definitely promotes the dialysability of iron and zinc, but its enhancing ability is highly specific to the food matrix.     

Validation of Extrusion as a Killing Step for Enterococcus faecium in a Balanced Carbohydrate-Protein Meal by Using a Response Surface Design

Outbreaks of salmonellosis and recalls of low-moisture foods including extruded products highlight the need for the food and feed industries to validate their extrusion processes to ensure the destruction of pathogenic microorganisms. Response surface methodology was employed to study the effect of moisture and temperature on inactivation by extrusion of Enterococcus faecium NRRL B-2354 in a carbohydrate-protein mix. A balanced carbohydrate-protein mix was formulated to different combinations of moisture contents, ranging from 24.9 to 31.1%, and each was inoculated with a pure culture of E. faecium to a final level of 5 log CFU/g. Each mix of various moistures was then extruded in a pilot scale extruder at different temperatures (ranging from 67.5 to 85°C). After the extruder was allowed to equilibrate for 10 min, samples were collected in sterile bags, cooled in dry ice, and stored at 4°C prior to analysis. E. faecium was enumerated with tryptic soy agar and membrane Enterococcus media, followed by incubation at 35°C for 48 h. Each extrusion was repeated twice, with the central point of the design being repeated four times. From each extrusion, three subsamples were collected for microbial counts and moisture determination. Based on the results, the response surface model was y = 185.04 - 3.11X(1) - 4.23X(2) + 0.02X(1)(2) - 0.004X(1)X(2) + 0.08X(2)(2), with a good fit (R(2) = 0.92), which demonstrated the effects of moisture and temperature on the inactivation of E. faecium during extrusion. According to the response surface analysis, the greatest reduction of E. faecium for the inoculation levels studied here (about 5 log) in a carbohydrate-protein meal would occur at the temperature of 81.1°C and moisture content of 28.1%. Other temperature and moisture combinations needed to achieve specific log reductions were plotted in a three-dimensional response surface graph.     

High-resolution change estimation of soil moisture using L-band radiometer and Radar observations made during the SMEX02 experiments

The soil moisture experiments held during June-July 2002 (SMEX02) at Iowa demonstrated the potential of the L-band radiometer (PALS) in estimation of near surface soil moisture under dense vegetation canopy conditions. The L-band radar was also shown to be sensitive to near surface soil moisture. However, the spatial resolution of a typical satellite L-band radiometer is of the order of tens of kilometers, which is not sufficient to serve the full range of science needs for land surface hydrology and weather modeling applications. Disaggregation schemes for deriving subpixel estimates of soil moisture from radiometer data using higher resolution radar observations may provide the means for making available global soil moisture observations at a much finer scale. This paper presents a simple approach for estimation of change in soil moisture at a higher (radar) spatial resolution by combining L-band copolarized radar backscattering coefficients and L-band radiometric brightness temperatures. Sensitivity of AIRSAR L-band copolarized channels has been demonstrated by comparison with in situ soil moisture measurements as well as PALS brightness temperatures. The change estimation algorithm has been applied to coincident PALS and AIRSAR datasets acquired during the SMEX02 campaign. Using AIRSAR data aggregated to a 100-m resolution, PALS radiometer estimates of soil moisture change at a 400-m resolution have been disaggregated to 100-m resolution. The effect of surface roughness variability on the change estimation algorithm has been explained using integral equation model (IEM) simulations. A simulation experiment using synthetic data has been performed to analyze the performance of the algorithm over a region undergoing gradual wetting and dry down.     

A Sucrose‐Mediated Sol–Gel Technique for the Synthesis of MgO–Y2O3 Nanocomposites

A sucrose‐mediated aqueous sol–gel procedure was developed to synthesize MgO–Y₂O₃ nanocomposite ceramics for potential optical applications. The synthesis involves the generation of a precursor foam containing Mg²⁺ and Y³⁺ cations via the chemical and thermal degradation of sucrose molecules in aqueous solution. Subsequent calcination and crushing of the foam gave MgO–Y₂O₃ nanocomposites in the form of thin mesoporous flake‐like powder particles with uniform composition and surface areas of 27–85 m² g ^{? 1}, depending on calcination conditions. The flakes exhibited a homogeneous microstructure comprising intimately mixed nanoscale grains of the cubic MgO and Y₂O₃ phases. This microstructure was resistant to grain coarsening with average grain sizes of less than 100 nm for calcination temperatures of up to 1200°C. The results indicate that the sucrose‐mediated sol–gel process is a simple effective method for making nanoscale mixed oxides.     

Transport and stability enhancement in interfacially and dimensionally constrained CO2 selective polymers embedded in nanoporous sieve membranes

Nanocomposite polymer and ultrathin film membranes have shown great promise in enhancing gas permeation and selectivity properties by interfacially straining polymer matrices, yielding structures of higher free volume. However, undesired particle aggregation and short temporal stability remain a big challenge. In the present study, an “inverse” architecture to conventional polymer nanocomposites was investigated, in which the polymer phase poly(l-trimethylsilyl-1-propyne) (PTMSP) was interfacially and dimensionally constrained in nanoporous anodic aluminum oxide (AAO) membranes. While with this architecture the benefits of nanocomposite and ultrathin film membranes could be reproduced and improved upon, also the temporal stability could be enhanced substantially. Gas permeabilities of helium, nitrogen and carbon dioxide were increased over five-fold, and selectivities of CO₂/He and CO₂/N₂ could be enhanced by 40% compared to the pristine bulk phase, while physical aging, caused by free-volume collapse, was reduced twenty-fold compared to ultrathin membranes.