Biometric identification using fingertip electrocardiogram signals

In this research work, we present a newly fingertip electrocardiogram (ECG) data acquisition device capable of recording the lead-1 ECG signal through the right- and left-hand thumb fingers. The proposed device is high-sensitive, dry-contact, portable, user-friendly, inexpensive, and does not require using conventional components which are cumbersome and irritating such as wet adhesive Ag/AgCl electrodes. One of the other advantages of this device is to make it possible to record and use the lead-1 ECG signal easily in any condition and anywhere incorporating with any platform to use for advanced applications such as biometric recognition and clinical diagnostics. Furthermore, we proposed a biometric identification method based on combining autocorrelation and discrete cosine transform-based features, cepstral features, and QRS beat information. The proposed method was evaluated on three fingertip ECG signal databases recorded by utilizing the proposed device. The experimental results demonstrate that the proposed biometric identification method achieves person recognition rate values of 100% (30 out of 30), 100\(\%\) (45 out of 45), and 98.33\(\%\) (59 out of 60) for 30, 45, and 60 subjects, respectively.     

Electrochemical Determination of Copper(II) in Water Samples Using a Novel Ion-Selective Electrode Based on a Graphite Oxide–Imprinted Polymer Composite

A novel copper(II)-selective electrode based on graphite oxide/imprinted polymer composite was developed for the electrochemical monitoring of copper(II) (Cu²⁺) ions. The electrode exhibited highly selective potentiometric response to Cu²⁺ with respect to common alkaline, alkaline earth and heavy metal cations. The composite composition studies indicated that the most suitable composite composition performing the most promising potentiometric properties was 20.0% ionophore (Cu²⁺-ion imprinted polymer), 10.0% paraffin oil, 5.0% multiwalled carbon nanotubes, and 65.0% graphite oxide. The fabricated electrode exhibited a linear response to Cu²⁺ over the concentration range of 1.0?×?10^??6–1.0?×?10^??1?M (correlation coefficient of 0.9998) with a sensitivity of 26.1?±?0.9?mV decade^??1. The detection limit of the fabricated electrode was determined to be 4.0?×?10^??7?M. The electrode worked well in the pH range of 4.0–8.0. The electrode had stable, reversible and fast potentiometric response (3?s). In addition, the electrode had a lifetime of more than 1 year. The analytical applications of the proposed electrode were performed using as an indicator electrode for the potentiometric titration of Cu²⁺ with ethylene diamine tetraacetic acid solution and for the determination of Cu²⁺ of spiked river, dam, and tap water samples. The obtained results for potentiometric titration and water samples were satisfactory.     

A new antibacterial diterpene from the roots of Salvia caespitosa

From the roots of Saliva caespitosa Montbret and Aucher ex. Bentham a new diterpene 6beta-hydroxyisopimaric acid (1) has been isolated together with four known diterpenes, one new triterpenoid, 3-acetylvergatic acid (2), as well as five known triterpenoids, two steroids and a flavone. The structures of the compounds were established by spectroscopic analyses. The isolated compounds were tested against standard bacterial strains. Only the new diterpene, 6beta-hydroxyisopimaric acid has strong activity (MIC 9 microg/ml) against S. aureus and (MIC 18 microg/ml) against S. epidermidis as well as against B. subtilis (MIC 9 microg/ml).     

Dipotassium maleate with boric acid

In the title compound, poly[(μ₃‐boric acid)‐μ₄‐maleato‐dipotassium], [K₂(C₄H₂O₄){B(OH)₃}]_n, there are two independent K⁺ cations, one bonded to seven O atoms (three from boric acid and four from maleate), and the other eight‐coordinate via three boric acid and four maleate O atoms and a weak η¹‐type coordination to the C=C bond of the maleate central C atoms. Hydrogen bonding links the boric acid ligands and maleate dianions, completing the packing structure.     

A predictive model for pressure fluctuations on sloping channels using support vector machine

In this study, support vector machine (SVM) is proposed as a new predictive model for pressure fluctuations beneath free jump occurring on sloping channels. The proposed model reproduces the pressure fluctuation intensity C′_p in terms of normalized flow and channel section characteristics. The model variables were derived from dimensional analysis. The proposed model is calibrated and validated by using a wide range of experimental data. The SVM predicted C′_p with a correlation of coefficient (CC) of 0.989 and a root mean square error (RMSE) of 0.004. Also, linear and nonlinear regression analyses are applied on the same experimental data set, and the SVM model is compared to the equations obtained from these regression analyses. CC, RMSE and average absolute deviation (D_i) are used in the evaluation of performance of each model. The SVM model predicted the measured pressure fluctuations better than conventional regression equations. The results of this study reveal that the proposed SVM model can be effectively used in predicting the pressure fluctuation beneath free jump. Copyright © 2010 John Wiley & Sons, Ltd.     

The necessity of reexamining previous life prediction analyses ofsolder joints in electronic packages

There are several different constitutive relations for describing the creep behavior of solder to predict the fatigue life of a solder joint. The differences among these constitutive relations for fatigue life prediction of electronic packages are unknown because analysts using finite element programs such as ABAQUS or ANSI'S are generally limited to specific built-in material models. The objective of this study is to implement a procedure that allows the use of various creep models in the analysis of electronic packages using ANSYS. Special user routines are developed so the user can incorporate virtually any creep relation and determine the inelastic strain energy density developed in the three-dimensional solid elements. Comparisons are performed for the modified creep routines and the viscoplastic formulation of Anand's model in ANSYS. It is found that the scheme used by ANSYS to determine plastic work density is incorrect and will be remedied in a future release. The implications of this revision to ANSYS are critical because a change in scheme will make comparisons with past studies and analyses difficult. The value of the empirical parameters based on previous analyses, which are widely used in the prediction of package fatigue life, will have to be reexamined