Modeling of the α-lactalbumin and β-lactoglobulin protein separation

This work used the General Rate Model (GRM) to evaluate the experimental data of α-lactalbumin (α-la) and β-lactoglobulin (β-lg) mass transfer using size exclusion chromatography (SEC). The chromatographic simulation has become necessary in large scale production processes. Mathematical models have been used for the optimization and control of different operating conditions of the process, as well as providing calculations for the process scale-up. For the SEC experiments, the aqueous biphasic system was composed of polyethylene glycol 1500 g/mol, potassium phosphate and whey protein isolate. The polymeric phase was enriched with α-la and the saline phase with β-lg. The experiments were conducted using a glass column packed with the Sephadex G-25^® gel. Both proteins were quantified by reverse phase liquid chromatography. The experimental data were fitted by non-linear regression, using the successive quadratic programming algorithm. The mass transfer model utilized represented adequately the SEC experimental results.     

Comparison of Ordinary Kriging, Regression Kriging, and Cokriging Techniques to Estimate Soil Salinity Using LANDSAT Images

The objectives of this study are: (1) to evaluate the LANDSAT best band combinations to estimate soil salinity with different crop types; (2) to compare ordinary kriging, regression kriging, and cokriging techniques to generate accurate soil salinity maps when applied to LANDSAT images; and (3) to compare the performance of different crop types: alfalfa, cantaloupe, corn, and wheat as indicators of soil salinity. This study was conducted in an area in the southern part of the Arkansas River Basin in Colorado. Six LANDSAT images acquired during the years: 2000, 2001, 2003, 2004, 2005, and 2006 in conjunction with field data were used to estimate soil salinity in the study area. The optimal subsets of band combinations from the LANDSAT images that correlate best with the soil salinity data sets were selected. Ordinary kriging, regression kriging, and cokriging were applied to 2,914 soil salinity data points collected in alfalfa, cantaloupe, corn, and wheat fields in conjunction with the selected LANDSAT image band combination subsets. Ordinary least-squares (OLSs) were used to regress the correlated band combinations to generate a soil salinity surface. The residuals of the OLS multiple regression model were kriged and combined with the soil salinity surface generated using the OLS multiple regression model to produce the final soil salinity surface of the regression kriging model. The same LANDSAT band combinations used with the regression kriging technique were used as secondary data variables with the cokriging technique, while the soil salinity data was used as a primary variable. The results show that the best band combinations for estimating soil salinity with different crops are as follows: alfalfa [red, near infrared, and normalized difference vegetation index (NDVI)]; cantaloupe (blue and green); corn (near, thermal, and NDVI); and wheat (blue and thermal). The performance of the different geostatistical models used in this study is: (1) ordinary kriging; (2) regression kriging; and (3) cokriging. Estimation of soil salinity works best for corn, then wheat, cantaloupe, and alfalfa.     

Carrier-Signal Selection for Sensorless Control of PM Synchronous Machines at Zero and Very Low Speeds

This paper compares pulsating- and rotating-vector carrier-signal injection for self-sensing (or sensorless) control of permanent-magnet synchronous machines (PMSMs). The main focus of this paper is the evaluation of estimation errors due to the physical nonideal attributes of both the machine and the inverter. Initial-position and magnet-polarity estimations are analyzed as well. Transient response and signal processing for both techniques are discussed for completeness. The theoretical analysis is supported by experimental and simulation evidence obtained using interior PMSMs.      

Energy analysis of electric vehicles using batteries or fuel cells through well-to-wheel driving cycle simulations

This work presents a study of the energy and environmental balances for electric vehicles using batteries or fuel cells, through the methodology of the well to wheel (WTW) analysis, applied to ECE-EUDC driving cycle simulations.     

Corrosion behavior of hypoeutectic Al-Cu alloys in H2SO4 and NaC1 solutions

alloys.     

Lung lamellar bodies lack certain key enzymes of phospholipid metabolism

Palmitoyl CoA-glycerol-3-phosphate acyltransferase, phosphatidate phosphohydrolase, and phospholipase A were assayed in subcellular fractions of rat lung, including lamellar bodies, the putative site of storage and secretion of lung surfactant. The specific activity of each of these enzymes in lamellar bodies was relatively low and could be entirely accounted for by a small contamination of the lamellar bodies fraction by microsomes, as quantitated by the presence of the microsomal marker reduced triphosphopyridine nucleotide cytochromec reductase. These data indicate that lamellar bodies are not the site of synthesis of the lipid component of pulmonary surfactant by pathways involving these enzymes.     

Automatic texture feature selection for image pixel classification

Pixel-based texture classifiers and segmenters are typically based on the combination of texture feature extraction methods that belong to a single family (e.g., Gabor filters). However, combining texture methods from different families has proven to produce better classification results both quantitatively and qualitatively. Given a set of multiple texture feature extraction methods from different families, this paper presents a new texture feature selection scheme that automatically determines a reduced subset of methods whose integration produces classification results comparable to those obtained when all the available methods are integrated, but with a significantly lower computational cost. Experiments with both Brodatz and real outdoor images show that the proposed selection scheme is more advantageous than well-known general purpose feature selection algorithms applied to the same problem.     

Analogue?digital phase-locked loop for alternating current quartz electrogravimetry

Requirements for frequency-voltage conversion in alternating current (AC) electrogravimetry are introduced. A new frequency-voltage conversion system based on a double tuning analogue-digital phase-locked loop is proposed. The reported results prove its reliability for AC electrogravimetry measurements     

Phase transition characteristics and dielectric properties of rare-earth (La,Pr, Nd,Gd) doped Ba(Zr0.09Ti0.91)O3 ceramics

A-site deficient rare-earth doped barium zirconate titanate (BZT) ceramics (Ba_1−yLn_2y/3)Zr_0.09Ti_0.91O₃ (Ln = La, Pr, Nd, Gd) are obtained by a modified solid-state reaction method. Perovskite-like single-phase compounds were confirmed from X-ray diffraction data. Morphological analysis on sintered samples shows that the addition of rare-earth ions inhibits the growth of the grain and remarkably changes the grain morphology. The effect of rare-earth addition to BZT on phase transition and dielectric properties is analyzed. A dramatic fall in the transition temperature occurs when BZT ceramic is doped with rare-earths. Moreover, diffusivity degree of the phase transition increases and a relaxor-type behaviour is induced due to both the increment of the lanthanide content and the increase of the ionic radius of the dopant element. High values of dielectric tunability are obtained for lanthanum doped BZT. A direct relation between transition temperature and tunability is discussed. Conclusively, low permittivity and high tunability materials can be obtained by the adequate substitution of rare-earths into BZT ceramics.