Optical and electrochemical studies of passive film formation in amorphous Ni‐Cr‐P‐C alloys

The investigation of passivation of an amorphous Ni‐l4Cr‐17P‐0.5C alloy in lN H2 SO4 through anodic polarization and near‐normal optical reflectance is reported. It was found that the alloy passivates with a current density of 10− 1 A/m2 extending to 1.0 V with current density dependent upon surface morphology. In the transpassive region under constant current density conditions the reflectance of the film exhibits strong interference phenomena and overall exponential decay in intensity. The behavior of the system in this region is described with a single thin‐film optical model consistent with the formation of a chromium phosphate deposit layer which increases in thickness at a rate of 7 nm/s at a 1.67 mV/s sweep rate

Not just numbers: beyond counting caesarean deliveries to understanding their determinants in Ghana using a population based cross-sectional study.

BACKGROUND:The increasing rate of caesarean deliveries (CD) has become a serious concern for public health experts globally. Despite this health concern, research on factors associated CD in many low- and -middle countries like Ghana is sparse. This study, therefore, assessed the prevalence and determinants of CD among child-bearing women aged 15-49  in Ghana. METHODS:The study used data from the 2014 Ghana Demographic and Health Survey. The analysis was limited to mothers (n = 2742) aged 15-49 , who had given birth in health facilities 5 years preceding the survey. Association between CD and its determinants was assessed by calculating adjusted odds ratios (AOR) with their respective 95% confidence intervals using a binary logistic regression. RESULTS:The percentage of mothers who delivered their babies through caesarean section (CS) was 18.5%. Using multivariable logistic regression, the results showed that women aged 45-49 (AOR = 10.5; 95% CI: 3.0-37.4), and women from a household that are headed by a female (AOR = 1.3; 95% CI = 1.1-1.7) had higher odds to deliver through CS. Women from the Upper East (AOR =0.4; 95% CI = 0.2-0.7) and Upper West (AOR = 0.4; 95% CI = 0.2-0.8) regions had lower odds to deliver their children through CS. Women with parity 4 or more (AOR = 0.3; 95% CI = 0.2-0.5) had lower odds of CD compared to those with parity 1. Women with female babies had lower odds (AOR = 0.8; CI = 0.7-0.9) of delivering them through CS compared to those with male children. CONCLUSION:The percentage of women delivering babies through the CS in Ghana is high. The high rates of CD noted do not essentially indicate good quality care or services. Hence, health facilities offering this medical protocol need to adopt comprehensive and strict measures to ensure detailed medical justifications by doctors for performing these caesarean surgeries

Energy and spectral enhancement of femtosecond supercontinuum in a noble gas using a weak seed

We experimentally demonstrate that the use of a weak seed pulse of energy less than 0.4% of the pump results in a spectral energy enhancement that spans over 2 octaves and a total energy enhancement of more than 3 times for supercontinua generated by millijoule level femtosecond pulses in Krypton gas. Strong four-wave mixing of the pump-seed pulse interacting in the gas is observed. The spectral irradiance generated from the seeding process is sufficiently high to use white-light continuum as an alternative to conventional tunable sources of radiation for applications such as nonlinear optical spectroscopy

Global distribution and interannual variations of mesospheric and lower thermospheric neutral wind diurnal tide: 2. Nonmigrating tide

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94716/1/jgra18976.pd

Artificial Neural Network-based error compensation procedure for low-cost encoders

An Artificial Neural Network-based error compensation method is proposed for improving the accuracy of resolver-based 16-bit encoders by compensating for their respective systematic error profiles. The error compensation procedure, for a particular encoder, involves obtaining its error profile by calibrating it on a precision rotary table, training the neural network by using a part of this data and then determining the corrected encoder angle by subtracting the ANN-predicted error from the measured value of the encoder angle. Since it is not guaranteed that all the resolvers will have exactly similar error profiles because of the inherent differences in their construction on a micro scale, the ANN has been trained on one error profile at a time and the corresponding weight file is then used only for compensating the systematic error of this particular encoder. The systematic nature of the error profile for each of the encoders has also been validated by repeated calibration of the encoders over a period of time and it was found that the error profiles of a particular encoder recorded at different epochs show near reproducible behavior. The ANN-based error compensation procedure has been implemented for 4 encoders by training the ANN with their respective error profiles and the results indicate that the accuracy of encoders can be improved by nearly an order of magnitude from quoted values of ~6 arc-min to ~0.65 arc-min when their corresponding ANN-generated weight files are used for determining the corrected encoder angle.Comment: 16 pages, 4 figures. Accepted for Publication in Measurement Science and Technology (MST

Putative markers for the detection of breast carcinoma cells in blood.

The aim of this study was to investigate certain genes for their suitability as molecular markers for detection of breast carcinoma cells using the reverse transcriptase-polymerase chain reaction (RT-PCR). RNA was prepared from MCF-7 breast carcinoma cells and peripheral blood leucocytes of healthy female volunteers. This RNA was screened for mRNA of MUC1, cytokeratin 19 (CK19) and CD44 (exons 8-11) by RT-PCR and the results validated by Southern blots. Variable degrees of expression of MUC1 and CD44 (exons 8-11) were detected in normal peripheral blood, rendering these genes non-specific for epithelial cells and therefore unsuitable for use as markers to detect breast carcinoma cells. Although CK19 mRNA was apparently specific, it was deemed unsuitable for use as a marker of breast cancer cells in light of its limited sensitivity. Furthermore, an attempt at using nested primers to increase sensitivity resulted in CK19 mRNA being detected after two amplification rounds in blood from healthy volunteers

Quantum effects in linguistic endeavors

Classifying the information content of neural spike trains in a linguistic endeavor, an uncertainty relation emerges between the bit size of a word and its duration. This uncertainty is associated with the task of synchronizing the spike trains of different duration representing different words. The uncertainty involves peculiar quantum features, so that word comparison amounts to measurement-based-quantum computation. Such a quantum behavior explains the onset and decay of the memory window connecting successive pieces of a linguistic text. The behavior here discussed is applicable to other reported evidences of quantum effects in human linguistic processes, so far lacking a plausible framework, since either no efforts to assign an appropriate quantum constant had been associated or speculating on microscopic processes dependent on Planck's constant resulted in unrealistic decoherence times

Global distribution and interannual variations of mesospheric and lower thermospheric neutral wind diurnal tide: 1. Migrating tide

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95689/1/jgra18975.pd

Dual-arm Z-scan Technique to Extract Dilute Solute Nonlinearities from Solution Measurements

We present a technique in which small solute nonlinearities may be extracted from large solvent signals by performing simultaneous Z-scans on two samples (solvent and solution). By using a dual-arm Z-scan apparatus with identical arms, fitting error in determining the solute nonlinearity is reduced because the irradiance fluctuations are correlated for both the solvent and solution measurements. To verify the sensitivity of this technique, the dispersion of nonlinear refraction of a squaraine molecule is measured. Utilizing this technique allows for the effects of the solvent n2 to be effectively eliminated, thus overcoming a longstanding problem in nonlinear optical characterization of organic dyes