This paper focuses on the validation of the latest version of the International Reference Ionosphere (IRI-2016) model in predicting the vertical total electron content (VTEC) variation over Ethiopian ionospheric region during a high solar activity (2012-2016) phase. The diurnal, monthly and seasonal VTEC variations were analyzed from dual-frequency global positioning system (GPS) and IRI-2016 model at the Debark station. The diurnal, monthly and seasonal maximum TEC values measured between around 9:00 and 18:00 UT (12:00 and 21:00 LT) hours and the minimum TEC values measured before 9:00 (12:00 LT) and after 18:00 UT (21:00 LT). The overall results show that IRI-2016 model generally overestimates the diurnal, monthly and seasonal mean VTEC values during the high solar activity (2012-2016) phase. The model prediction generally follows that the monthly and seasonal variations of the measured VTEC values in equinoctial months are higher than solstice months. The monthly mean and seasonal mean values of IRI-TEC and GPS-TEC mostly correlates before early morning and after evening hours and also slightly IRI-TEC underestimates starting from morning hours up to evening hours. The magnetic storm effects on GPS-TEC are associated with fluctuations. However, the IRI-TEC values show smooth pattern during both in storm on and off options. Consequently, the IRI-2016 model does not correctly respond to the effects of the resulting storm disturbance.

Banking sector in Ethiopia is dominant and  it is a dense competent area. Due to this the bank managements tend to continually found the strategies that enables them to be competent in this dense competition. These strategies often focus on handling of customers satisfaction to be strongly compete and pooling more customers. Because, service quality is relevant to keep up their competitive advantage and improve customer satisfaction. So, this study examine the handling of customers satisfaction and assessment of service qualities on Commercial Bank of Ethiopia (CBE) in Addis Ababa at East District by applying SERVQUAL model. This study used convenient and random sampling technique to select the sample respondents and 400 respondents were selected branches of CBE in Addis Ababa at east district. The data sources for this study are primary and secondary data sources. The questionnaires are used as primary data source, which are contained SERVQUAL model and the agreements were measured by applying the five Likert point scales. The correlation result revealed that all dimensions of service quality have a strong and significant statistical relationship with customer satisfaction. The quality of service offered by CBE no meets with the expectation of customer (customers satisfied in somewhat quality service). So, the bank needs to reform service quality for satisfy and attract unsatisfied customers.

Assessing bottled mineral water with drinking water guidelines set by the World Health Organization (WHO) and the Ethiopian Standard Agency (ESA) are highly relevant for practitioners, bottling companies, managers, regulators, and policymakers regarding water supply particularly bottled water. The present study was carried out to report the physicochemical quality of six branded bottled mineral water widely available in the Ethiopian market and compare them with drinking water standards. The investigated physicochemical parameters were pH, electrical conductivity (EC), total dissolved solids (TDS), chloride ion (CL - ), nitrate ion (NO3 - ), potassium (K+ ), sodium (Na+ ), zinc (Zn+ ), iron (Fe3+), calcium (Ca2+) and magnesium ion (Mg2+) using standard analytical techniques. Flame Atomic Absorption Spectroscopy (FAAS) was used to determine the number of metal elements. The Ultra Violet-Visible Spectrophotometer (UV-VIS) analysis was used to determine the amount of NO- in the bottled mineral water. The TDS and CL-values were determined by using gravimetric and volumetric methods. The study results revealed that the values of the quality parameter concentrations measured experimentally were slightly varied from the labeled values on the bottle. However, all brands were within EAS and WHO limit values for drinking water. The calculated correlation coefficient between the bottled water and the soil sample, between some dissolved solids and the TDS concentration in bottled mineral water, and between TDS and the pH concentration in bottled mineral waters was 0.99, 0.77 and 0.94, respectively. The study also verified that all the studied bottled water brands are safe for human consumption.

In this paper we access the effects of two atmospheric variables (temperature and relative humidity) on two important pollutants in the atmosphere (Nitrogen oxides (NOx) and carbon monoxide (CO)) by using one year (2016) data of Addis Ababa. Temperature has impact on atmospheric mixing and cause for the reduction of NOx as temperature increases. There are positive correlation between temperature and CO concentration from January to April with (R2 = 0.69), negative correlation from May to August with (R2 = 0.92) and no correlation for the remaining months. NOx and CO have moderate positive and negative correlation with relative humidity during the months January-April (R2 = 0.294 for NOx and R2 = 0291 for CO) and in the months May-August are R2 = 0.97 and R2 = 0.15 for NOx and CO respectively. But there are no clear correlation between the NOx and CO with relative humidity from September-December. NOx concentrations during wet season was almost about twice that of the dry season, but no such difference was observed in the case of CO. The seasonal average air temperature in wet season is relatively lower than dry season. NOx exhibited positive and CO negative seasonal correlations with relative humidity.

This study presents the performance evaluation of International Reference Ionosphere extended to the plasmasphere (IRI-Plas 2017) model from the Addis Ababa ionosonde station, Ethiopia ionospheric parameters measurement with geographic latitude 9.00o N and longitude 38.70o E; geomagnetic latitude 0.16, geomagnetic longitude 110.44) in selected days of the year 2014. During comparison, hourly and day-to-day variability of ionospheric parameters of the electron density profile, peak electron density (NmF2), peak height (hmF2) and critical frequency (foF2) measurements are consider. In the evaluation of the IRI-Plas 2017 model with the ionosonde data, the percentage deviation and the correlation coefficient (R) is used as the measure of the performance of the IRI-Plas 2017 model. The overall results, show that the IRI-Plas 2017 model mostly overestimates in most altitudes and hours of electron density measurements. The IRI-Plas 2017 model has a good agreement with the ionosonde electron density measurement from 100 km to 200 km altitude and mostly during in between 0:00-06:00 UT and 12:00-18:00 UT hours, while the model biases in other altitudes and hours with overestimate or underestimate in the ionosonde electron density measurements. The IRI-Plas 2017 model has a good correlation during after midnight and around midday hours with about ±2 percentage deviation from the ionosonde electron density measurement. The model has high percentage deviation value of electron density measurements mostly in between altitudes from 200 km to 450 km and during early nighttime and before midnight hours. The IRI-Plas 2017 model measurements of the NmF2, hmF2 and foF2 mostly underestimates from the ionosonde data during the night-time (18:00 UT- 06:00 UT) and overestimates during day-time (06:00 UT-18:00 UT). The IRI-Plas 2017 model measurement of the foF2 values are in a good agreement with the ionosonde result than in hmF2 and NmF2 and the model measurement of the NmF2 values are closer than hmF2.