Exploring the Use of Covellite as a Proxy for Corrosion of Native Copper by Sulphur Reducing Bacteria

We are analyzing the effect of sulphate reducing bacteria on native copper, and using that evidence to further support the initiative of having a deep geological repository to store nuclear material. Sulphate reducing bacteria are a concern for the deep geological repository as they cause the corrosion of regular copper. However native copper has gone billions of years without corrosion, which could either mean that it had not been exposed to sulphate reducing bacteria over the billions of years, or native copper is able to withstand corrosion despite the contact of sulphate reducing bacteria. We can find out by trying to find the biomarkers of sulphate reducing bacteria on native copper, which through literature search are found to be copper sulphide also known as Covellite. By using an electron microscope to search for Covellite on the native copper sample, we can determine if, and how sulphate reducing bacteria affects native copper. A further application of this experiment would be to see how to implement this characteristic of native copper onto the copper used in the deep geological repository

EKG De-noising using 1-D Wavelets Techniques

© ASEE 2009The electrocardiogram (ECG or EKG) is a graphic recording or display of the time- variant voltages produced by the myocardium during the cardiac cycle. The P, QRS, and T waves reflect the rhythmic electrical depolarization and re-polarization of the myocardium associated with the contractions of the atria and ventricles. The electrocardiogram is generally used clinically in diagnosing various diseases and conditions associated with the heart. It also serves as a timing reference for other measurements. Hence its accurate measurement is a must. A normal EKG waveform consists of common mode noises such as dc electrode offset potential and 50 or 60 Hz ac-induced interference. This paper presents the study of filtering these noises using 1-Dimensional wavelets theory. Wavelets are mathematical functions that cut up data into different frequency components, and then study each component with a resolution matched to its scale. They have advantages over traditional Fourier methods in analyzing physical situations where the signal contains discontinuous and sharp spikes

Maternal outcome amongst all deliveries of nullipara in spontaneous labor at term ≥37 weeks at a tertiary health care center in south Gujarat, India

Background: Since last one decade there is rising concern over increasing rate of caesarean section in all over world, especially among nulliparous women. The national prevalence of CS in India has modestly increased over the past 25 years. According to data from the National Family Health Survey, the national CS rate in 1992-93 was 2.6% and rose to 17.2% in 2015-16. Study objective was to evaluate fetomaternal outcome of Nullipara >=37wks pregnancy in spontaneous labor. Methods: This prospective observational study was done at Obstetrics and Gynaecology Department of New Civil Hospital Surat for 6 months period after official approval from Ethical Committee. Results: In my study 65% subjects had normal vaginal delivery, 34% subjects had cesarean section and 1% had operative vaginal delivery. In comparison between total no. Of ANC visit and postpartum/intrapartum complication p-value is 0.003 which is p <0.05, which is significant, which suggests that women with 4 or less total ANC visits have higher risk of developing postpartum/intrapartum complication than women with more than 4 total ANC visits. Conclusions: The primary caesarean section among nulliparous singleton pregnancy with spontaneous labor is an important contributor to overall caesarean section of the health institute. The main indication for caesarean section were fetal distress, cephalo-pelvic disproportion and meconium stained liquor in early phase of labor. There is need to develop standard clinical protocol for management of these conditions and to promote vaginal delivery in nulliparous singleton pregnancy with spontaneous labor in eligible

EKG De-noising using 2-D Wavelet Techniques

© ASEE 2009The electrocardiogram (ECG or EKG) is a recording of the potential produced by the heart, taken from specific predetermined parts of the body such as arms, legs or points on the chest. It plays an important role in medical field as monitoring of human body and the diagnosis of many heart related problems depend on the recording. Hence its accurate measurement is a must. This paper presents the study of filtering the noises present in an EKG waveform using 2-D wavelet techniques. Wavelets are mathematical functions that cut up data into different frequency components, and then study each component with a resolution matched to its scale. Wavelets are predominantly used for image processing techniques. Hence to use a 2-D technique over a 1-D signal, an EKG should be represented as a mesh or a 2-D image map. Such an image map, or an EKG map in this case, can be used by wavelet processing for de-noising purposes. The de-noising procedure is performed using three steps: decomposition, thresholding and reconstruction. The paper discusses the mentioned steps in detail

Minimizing Common Mode Interferences in the Measurement of Bio-Signals

Bio-signals are signals that can be measured from a living being. Electrical bio-signals are the result of depolarization and repolarization of the cells in a specialized tissue, organ or cell system. Accurate reading and analysis of signals such as electrocardiogram (ECG or EKG), electroencephalogram (EEG), electromyogram (EMG) etc. is very important as they are used clinically in diagnosing diseases. Hum interference is caused by magnetic and electric fields from power lines and transformers cutting across the measuring electrodes and patients. This type of noise seems to be ever-present, although the modern noise reduction techniques are successful in minimizing this in signal recordings. We discuss a method to minimize such interference using a pre-amplifier design with a very high common mode rejection ratio of 131 dB at 60 Hz and high input impedance. A comparison of the design with the commercially available Instrumentation Amplifier is also done. We verify our results using computer simulation of an ECG signal via the software Multisim

A Study of the Relationship between Head Related Transfer Functions and Elevations

Head Related Transfer Functions (HRTFs) are signal processing models that represent the transformations undergone by acoustic signals, as they travel from their source to the listener’s eardrums. The study of HRTFs is a rapidly growing area with potential uses in virtual environments, auditory displays, the entertainment industry, human-computer interface for the visually impaired, aircraft warning systems, etc. The positioning of the sound source plays a major role in the resonant frequency of the HRTFs. In this paper, we examine the effect of changing the elevations of these sources; we examine the effect on the first peak and the first notch of HRTFs. We use the HRTF database at FIU DSP lab. This database hosts the HRTFs from 15 subjects and their 3-D images of conchas. For each subject, the database contains the Head Related Impulse Responses (HRIRs) for the sound sources placed at six elevations (54°, 36°, 18°, 0°, -18° and -36°) and twelve azimuths (180°, 150°, 120°, 90°, 60°, 30°, 0°, -30°, -60°, -90°, -120° and -150°). A relationship between the first peak or notch and the elevation can help us model HRTFs mathematically. This can reduce the size of a HRTF database and can increase the speed of HRTF related computations

Real Life High Voltage Accident Cases - Teaching Electrical Safety

© ASEE 2012We discuss the engineering principles of Hi-voltage (any voltage above 600 volts). We cite 4 examples that typify some of the problems facing the Engineer and technician working with Hi-voltages, including geometry considerations, the need to follow proper protocol and the laws (both scientific and political) governing Hi-voltage. Poor design considerations in capacitor construction is the first case we consider, as well as the lack of proper protocols in discharging same. In the second case, a warning can be made that one should never get too close to a Hi-voltage line, unless the power is cut. In the third case, following simple rules in measurement of an unknown voltage could avoid a serious accident. In the fourth case, a high voltage shows up in a low-voltage circuit. These unfortunate cases are used as teaching tools to impart details of electrical safety in common industrial setting

A Modern but Simple Approach to Teaching Friction

© ASEE 2008We present an experiment for measuring friction, using interleaved sheets of paper. Our results support the modern theory that friction is dependent on surface contact area (A). Also, our results support the classical theory of friction being proportional to the normal force (N), but this is only true over a limited range of N, where the “effective” area of contact increases in a manner proportional to N. Outside of this range, friction varies nonlinearly with N but linearly with A. Suggestions are made for extending the function of this experiment to measure the friction of other materials. Also, we present techniques to limit the nonlinear behavior of N and to eliminate several key sources of experimental error

Electrical Grounding - theory and application

© ASEE 2011We discuss the engineering principles of Hi-voltage (any voltage above 600 volts). We cite 4 examples that typify some of the problems facing the Engineer and technician working with Hi-voltages, including geometry considerations, the need to follow proper protocol and the laws (both scientific and political) governing Hi-voltage. Poor design considerations in capacitor construction is the first case we consider, as well as the lack of proper protocols in discharging same. In the second case, a warning can be made that one should never get too close to a Hi-voltage line, unless the power is cut. In the third case, following simple rules in measurement of an unknown voltage could avoid a serious accident. In the fourth case, a high voltage shows up in a low-voltage circuit. These unfortunate cases are used as teaching tools to impart details of electrical safety in common industrial setting

Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

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