A process control method for the electric current-activated/assisted sintering system based on the container-consumed power and temperature estimation

Journal of Thermal Analysis and Calorimetry - In this paper, the current, voltage and temperature of the container of an electric current-activated/assisted sintering (ECAS) system are measured and...     

Ensemble Approach for Detection of Depression Using EEG Features

Depression is a public health issue that severely affects one’s well being and can cause negative social and economic effects to society. To raise awareness of these problems, this research aims at determining whether the long-lasting effects of depression can be determined from electroencephalographic (EEG) signals. The article contains an accuracy comparison for SVM, LDA, NB, kNN, and D3 binary classifiers, which were trained using linear (relative band power, alpha power variability, spectral asymmetry index) and nonlinear (Higuchi fractal dimension, Lempel–Ziv complexity, detrended fluctuation analysis) EEG features. The age- and gender-matched dataset consisted of 10 healthy subjects and 10 subjects diagnosed with depression at some point in their lifetime. Most of the proposed feature selection and classifier combinations achieved accuracy in the range of 80% to 95%, and all the models were evaluated using a 10-fold cross-validation. The results showed that the motioned EEG features used in classifying ongoing depression also work for classifying the long-lasting effects of depression.     

Modified Burgers-Reimschuessel model for moisture-sensitive polymers

Viscoelastic properties of moisture-sensitive polymers can be significantly affected by moisture in the ambient environment, resulting in drastic changes in the properties as the absorbed moisture content increases. In this article, a simple yet important modification to the Reimschuessel model is introduced by considering both plasticization and anti-plasticization induced by water molecules. The proposed model is validated against the results of four different polymers obtained by Onogi et al., which demonstrates its capability of describing the available data. This model can be used to estimate the performance and service life of products produced using moisture-sensitive polymers. It also reveals that small amounts of diffused moisture might have a stiffening effect on the mechanical properties of hydrophilic polymers.     

A study on theoretical predictive model and experimental findings of melt-electrospinning process

The current study extends a previous work published by the authors in which an analytical predictive model is proposed to simulate the melt-electrospinning process. The analytical model is specifically designed to predict the various behaviors of the melt-electrospun fiber under different material and processing conditions. A brief discussion of this model is presented here to establish context and help the reader capture the modeling philosophy employed. The current study complements the previous work by focusing on the experimental aspects of the research. Correlations between the independent process parameters and the topological attributes of the melt-electrospun fibers are investigated and compared with findings from the theoretical model. The effects of changes in the process parameters on average fiber diameters and the collection diameter are experimentally analyzed using the design of experiments (DOE) techniques. Toward this end, polylactic acid (PLA) is melt-electrospun at different treatment levels of the processing parameters in a controlled environment. Two regression-based models—one for predicting the collection diameter and the other for the fiber diameter—are derived from the DOE data for benchmarking and quantitative evaluation of the predictive performance of the theoretical model. The theoretical model is run based on the same treatment levels as the experiment. The elastic parameter values used in the theoretical simulation are extracted from rheological tests. Comparison between the simulated and the observed fiber characteristics revealed that the collector diameter predictions by the theoretical model exhibited approximately a 16.7% difference compared to 24.2% for the average fiber diameter. Finally, a discussion is presented on the challenges and potential factors contributing to the observed differences. Overall, given the identified challenges and gaps in material characterization, the results of the theoretical predictive model are encouraging.     

A Direct Proof of the Gale–Nikaido–Debreu Lemma Using Sperner’s Lemma

Journal of Optimization Theory and Applications - The Gale–Nikaido–Debreu lemma plays an important role in establishing the existence of competitive equilibrium. In this paper, we use...     

Ribozyme-mediated signal augmentation on a mass-sensitive biosensor

Mass-based detection methods such as the quartz crystal microbalance (QCM) offer an attractive option to label-based methods; however the sensitivity is generally lower by comparison. In particular, low-molecular-weight analytes can be difficult to detect based on mass addition alone. In this communication, we present the use of effector-dependent ribozymes (aptazymes) as reagents for augmenting small ligand detection on a mass-sensitive device. Two distinct aptazymes were chosen: an L1-ligase-based aptazyme (L1-Rev), which is activated by a small peptide (MW approximately 2.4 kDa) from the HIV-1 Rev protein, and a hammerhead cleavase-based aptazyme (HH-theo3) activated by theophylline (MW = 180 Da). Aptazyme activity was observed in real time, and low-molecular-weight analyte detection has been successfully demonstrated with both aptazymes.     

Polyelectrolytes in thin liquid films

The review addresses the influence of polyelectrolytes on the statics and dynamics of thin liquid films. Both, changes of interfacial and bulk properties, contribute to the overall behaviour of thin films formed from aqueous polyelectrolyte solutions. Therefore, the chapter is separated into two parts: polyelectrolytes at film interfaces and polymers in film bulk.     

Can Extensional Flow Rupture Macromolecules in an Electrospinning Process?

The fracture of high molecular weight poly(ethylene oxide) (PEO) chains under extensional stretching during the electrospinning of aqueous solutions was investigated by measuring solution viscosities and monitoring the change of molecular weight. The degree of macromolecular chain fractures in 1.0% polymer solutions increased with the increase in molecular weight. The strain rates for stretching and fracturing of macromolecules are critical for the degradation of polymers along with experimental elongational strain rates. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1051–1054     

Immunomagnetic diffractometry for detection of diagnostic serum markers

We describe an integrated approach for detection of diagnostic markers using in situ assembled optical diffraction gratings in combination with immunomagnetic capture. Folate receptor (FR), a serum protein indicative of various cancers, was chosen as a model system to demonstrate the potential of the method. Magnetic beads coupled to FR antibody were used to capture FR from serum. The FR-bound magnetic beads self-assembled onto microcontact-printed folate-coupled BSA (F-BSA) patterns to form diffraction gratings which served to detect FR by measuring the diffraction intensities caused by laser illumination. The FR-containing beads, upon binding to the F-BSA surface, served as intrinsic signal enhancement agents, circumventing the need for additional enzymatic signal amplification or fluorescent labeling steps. With this approach, a detection sensitivity of 700 fM (20 pg/mL) was achieved. The potential use of this approach in clinical diagnostics was demonstrated by measuring FR concentration in blood samples obtained from cancer patients.