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Papers by alemayehu keno
Latin-American Journal of Physics Education, 2014
This work focuses on the study of electroluminescence (EL) intensity from GaN nanoclusters (ncs) ... more This work focuses on the study of electroluminescence (EL) intensity from GaN nanoclusters (ncs) as a function of different parameters, such as size of the ncs, applied voltage, wavelength, temperature, and time. To do this, we used the idea of quantum confinement model (QCM) and developed model equation that describes the EL intensity as a function of size of the nanoclusters and Fourier transform of the size dependent intensity into energy dependent intensity equations were derived; as well as experimentally fit equations were used and MATLAB codes were developed to generate data. From our result it is shown that as the number of ncs decreases, higher EL intensity is obtained. However, selecting the number of samples is based on the applied voltage and wavelength. The high efficient EL is obtained at low operating voltages about 6V (in our case). It is also observed that EL intensity decreases as the temperature increases and degrades with time.
Background Preeclampsia is one of the leading causes of maternal and fetal morbidity and mortalit... more Background Preeclampsia is one of the leading causes of maternal and fetal morbidity and mortalities worldwide. Despite extensive research, the underlying cause of preeclampsia remains poorly understood. This study aimed to offer compelling evidence on the important risk factors of preeclampsia in Amhara region, Ethiopia. Methods A case control study was conducted in public health facilities of Bahir Dar city from September 2014 to January 2015. A total of 453 (151 cases and 302 controls) pregnant women were enrolled in this study. Hemoglobin level and urinary tract infection (UTI) status were collected from clinical notes. Oral examination was performed by a dentist for detection of periodontal diseases. Univariate and multiple logistic regression analysis was conducted to determine the relationship of all the independent variables with the outcome variable. A p-value <0.05 was declared statistically significant. Result Advanced maternal age (AOR=4.79;95% CI 1.031-22.18), family...
Latin-American Journal of Physics Education, 2014
This work focuses on the study of electroluminescence (EL) intensity from GaN nanoclusters (ncs) ... more This work focuses on the study of electroluminescence (EL) intensity from GaN nanoclusters (ncs) as a function of different parameters, such as size of the ncs, applied voltage, wavelength, temperature, and time. To do this, we used the idea of quantum confinement model (QCM) and developed model equation that describes the EL intensity as a function of size of the nanoclusters and Fourier transform of the size dependent intensity into energy dependent intensity equations were derived; as well as experimentally fit equations were used and MATLAB codes were developed to generate data. From our result it is shown that as the number of ncs decreases, higher EL intensity is obtained. However, selecting the number of samples is based on the applied voltage and wavelength. The high efficient EL is obtained at low operating voltages about 6V (in our case). It is also observed that EL intensity decreases as the temperature increases and degrades with time.
Background Preeclampsia is one of the leading causes of maternal and fetal morbidity and mortalit... more Background Preeclampsia is one of the leading causes of maternal and fetal morbidity and mortalities worldwide. Despite extensive research, the underlying cause of preeclampsia remains poorly understood. This study aimed to offer compelling evidence on the important risk factors of preeclampsia in Amhara region, Ethiopia. Methods A case control study was conducted in public health facilities of Bahir Dar city from September 2014 to January 2015. A total of 453 (151 cases and 302 controls) pregnant women were enrolled in this study. Hemoglobin level and urinary tract infection (UTI) status were collected from clinical notes. Oral examination was performed by a dentist for detection of periodontal diseases. Univariate and multiple logistic regression analysis was conducted to determine the relationship of all the independent variables with the outcome variable. A p-value <0.05 was declared statistically significant. Result Advanced maternal age (AOR=4.79;95% CI 1.031-22.18), family...