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A Mixed Effect Model for Unbalanced Longitudinal Haematocrit Level Evolution Progress of Chronic Kidney Failure Patients
(Mekelle University, 2023-11-28) Getachew Beyene
Background: Chronic Kidney Disease (CKD) or renal failure is a public global health problem with an estimated prevalence of as 8 to 16% worldwide. This study was conducted inorder to investigate the evolution of hematocrit levels over time in renal patients after their transplant and to determine how the evolution depends on the age and gender of the patient and other factors. Objective: The main objective of this study is to employ a mixed effect model to examine the unbalanced longitudinal evolution progress of hematocrit levels in chronic kidney failure patients. Methodology: This is a longitudinal study that consisted of 1160 patients who received a renal transplant. These patients were followed up for a period of 10 years at most. Haematocrit level was considered as the response while the covariates were time in years, gender and age of the patients just to mention a few. Different statistical methods such as explanatory analysis, multivariate regression model, two stage analysis and linear mixed effects model were employed to explore the evolution of hematocrit over time. Results: Results revealed that haematocrit levels in kidney transplantpatients evolve over time. Gender and age of the patient have significant effect on the evolution of haemotocrit levels. Males tend to have a higher increase in haematocrit levels over time than females. With regard to age, haematocrit levels tend to increase with increasing age. Furthermore, it was observed that experience of cardio-vascular problems before transplant and rejection symptoms did not have a significant effect on the evolutionof haematocrit levels. Conclusions: Hematocrit levels evolve over time and this evolution follows a quartic time effect. The change in haematocrit levels varies according to the gender and age of the patient after a kidney transplant. Patients starting with low haematocrit levels tend to have a larger increase overtime.
A Multilevel Structural Equation Modeling Approach to Estimate Incompletion of Childhood Vaccination among 12-39 months old in Ethiopia
(Mekelle University, 2023-11-28) Brtawit Aregay
Background: Childhood immunization is a worldwide ultimate public health intervention significantly plummeting morbidity and mortality linked with preventable diseases. Despite significant efforts to improve vaccination coverage, a considerable proportion of children aged 12-39 months in Ethiopia remaining incompletely vaccinated. Objective: This study intended to employ a Multilevel Structural Equation Modeling (MSEM) approach and framework to broadly analyze the elements contributing to incompleteness of childhood vaccination in Ethiopia. Methods: The study utilized secondary data from the Ethiopian Mini Demographic and health Survey (EMDHS) and adopted both qualitative and quantitative research approaches under descriptive research design. A multilevel logistic regression approach was employed to capture the interplay between individual and community-level factors impacting childhood vaccination status. At individual level, age, sex, education, marital status, and vaccination card were considered, while at the community level, factors such as antenatal care, place of delivery, poverty, media exposure, and living area were explored. The study established a conceptual model integrating these factors and applied a multilevel structural equation modeling approach to estimate their direct and indirect relations with incomplete childhood vaccination. On top of this, the pathways and interdependencies between variables were examined to elucidate the complex associations influencing vaccination outcomes. Results: Preliminary analyses revealed significant direct effects of urban residence (AOR=2.1 & 95%CI of AOR [1.1,3.6] and age (AOR=11.5 & 95% CI of AOR [1.1,2.1]) On childhood vaccination. Additionally, community-level factors such as primary school maternal education (AOR=1.8 & 95% CI of AOR [1.3, 2.5]) and antenatal care follow-up (ANC: AOR=1.5 & 95%CI of AOR [1.0,2.2]) demonstrated varying degrees of influence on vaccination status. Conclusions: The findings from this study grasp noteworthy implications and roles for national and global public health interventions. By identifying the multilayered elements impacting incomplete child vaccination, this research aims to provide evidence-based recommendations to reinforce vaccination programs and reduce the burden of vaccine-preventable diseases among Ethiopian children aged 12-39 months. Furthermore, the contributions of this study lie in its application of a wide-ranging multilevel structural equation modeling (MSEM) approach and framework, offering a nuanced understanding of the intricate web of determinants contributing to incomplete childhood vaccination in Ethiopia. The results are expected to inform targeted interventions and policy changes aimed at enhancing vaccination rates and safeguarding the health of children in national and regional level of Ethiopia as particular and worldwide in general.
A Study of the Impact of Feedback-Integrated Continuous Assessment on Grade 12 Students’ chemistry achievement: The case of Medhanealem Preparatory School, Addis Ababa, Ethiopia
(Mekelle University, 2025-01-25) BIRUK GEMECHU ABEBE
Feedback is often overlooked in continuous assessment despite its potential to enhance student outcomes. This study examines the impact of feedback-integrated continuous assessment on Grade 12 students' chemistry achievement at Medhanealem Preparatory School in Addis Ababa. The study involved three groups: two experimental groups (one with feedback-integrated continuous assessment and one with continuous assessment without feedback) and one comparison group (traditional exercises and activities). A mixed-methods approach was used, combining quantitative (quasi-experimental) and qualitative (case study) data. Instruments included pre- and post-achievement tests and semi-structured interviews with teachers from the experimental groups. Data were analyzed using SPSS (version 26), applying One-way and Two way ANOVA, and Pearson Correlation tests to compare group scores. Post-test results revealed a statistically significant improvement in the experimental groups compared to the comparison group (p < 0.05). A significant relationship was also found between continuous assessment scores and post-test outcomes. Qualitative data from interviews and classroom observations highlighted that feedback-integrated continuous assessment positively influenced students' chemistry achievement. The study suggests that incorporating feedback into continuous assessment allows teachers to adapt instruction to better meet individual student needs, ultimately improving learning outcomes. Based on these findings, it is recommended that teachers design feedback-oriented assessments aligned with curriculum objectives and clearly communicate performance expectations to enhance student learning
Adsorption-Based Defluoridation of Water Using Volcanic Rock Materials
(Mekelle University, 2025-06-28) Tekle Brhanu Gessesew
Fluoride (F-) contamination in water poses serious health risks, demanding effective and affordable removal methods. Therefore, this study aimed to evaluate activated pumice, which is a low-cost and ecofriendly adsorbent, for the removal of fluoride via batch adsorption. The pumice was activated by thermal treatment at 550°C followed by acid treatment with 0.1M HCl, enhancing its surface area and reactivity. The material was characterized using Scanning Electron Microscope, X-ray diffraction, and Fourier-Transform Infrared Spectroscopy. SEM images showed fractured, porous, and rough surface morphology favorable for adsorption. XRD analysis revealed a broad hump, indicating an amorphous structure, the FTIR spectra also showed peaks around 3740 cm-1, corresponding to O-H stretching, confirming the presence of hydroxyl groups and surface-bound water molecule; while peaks at 1001 cm-1 and 779 cm-1 confirming the presence of a silicate, aluminosilicate framework. Key parameters, including contact time (15–90 min), pH (3–11), dose (0.5–2.5 g), and initial fluoride concentration (2– 14 mg/L), were optimized at a constant shaking rate (250 rpm) at room temperature. Maximum Fremoval occurred at a contact time of 60 min, a dose of 0.5 g, and an initial F- concentration of 10 mg/L. A UV-visible spectrophotometer was utilized to measure F- using the SPADNS reagent (2- parasulfophenylazo)-1,8-dihydroxy-3,6-naphthalene disulfate. Adsorption kinetics followed the pseudosecond-order model (R2=0.99), described by the Freundlich isotherm model (R2 =0.99), indicating multilayer adsorption on a heterogeneous surface. A field study using a real water sample from Semema, Tigray, Ethiopia, demonstrated a maximum adsorption capacity of 1.59 mg/g. These findings indicated that activated pumice is a promising locally available material for F- removal, offering an effective and sustainable option for community water treatment.
ALTITUDE VARIATIONS ON ATHLETES’ PERFORMANCE ON SELECTED HEMATOLOGICAL AND PHYSIOLOGICAL VARIABLES
(Mekelle University, 2025-05-25) TESFAYE MOGES
The purpose of this study was to compare the effect of altitude training on athletes’ performance on selected hematological and physiological variables and to forward possible solutions. In this study, a quasi-experimental design was employed. To select the subjects of the study, a simple random sampling technique particularly the lottery method was employed. The study subjects (N=45) male trainees from Jinka, Hagereselam, and Bekoji athletics training centers aged from 16-20 were included. The selected samples were grouped into three (n=15) short-distance groups, (n=15) middle-distance group and (n=15) long-distance group. The selected Hematological variables were, RBC, Hb, HCT, and PLT vribles were tasted by Hematology Analyzer and the Physiological variables were, Vo2max tasted by Beep test, ResHR and RecHR tasted by portable FT1 Polar Heart Rate Monitor, BHC tasted by Nose clipper, SAP, and MAP tasted by mercury sphygmomanometer. To gather the necessary data standardized instruments and measurements were employed. The statistical techniques used in this study were ANCOVA; post hoc multiple comparison and LSD post hoc test confident interval at the significant level of 0.05. Besides this to compare the post hoc test results mean differences between the three groups were employed. Results of the hematological variables indicated that the Red Blood Cell showed no significant difference but Hemoglobin, Hematocritic, and Platelet count significant differences were seen between short, middle, and long-distance trainees. The physiological variables result also indicated that Vo2max, resting heart rate, breath-holding capacity, systolic blood pressure, and Mean Arterial Pressure no significant difference was observed between short and long-distance trainees but the middle-distance trainees were rated a significant difference in Vo2max and systolic blood pressure but on resting heart rate, recovery heart rate breath holding capacity, and mean arterial pressure no significant difference was observed. The result concluded that both the hematological and physiological variables showed insignificant among the training center trainees
Analysis of Multi-environmental Trial Data Using AMMI and GGE Biplot on Barley Genotypes Evaluated in Tigray
(Mekelle University, 2023-11-08) Tamrat Berhe
Barley (Hordeum vulgare L.) was one of the first plants people grew for food, and now it's grown all over the world and it has a special role in Ethiopian agriculture. However, production is affected by environment interaction and lack of stable genotypes across locations. The presence of genotype-environment interaction (GEI) influences production making the selection of cultivars in a complex process. Since, this experiment were conducted for forty barley genotypes by Alpha lattice design using two replications at three locations in Tigray during 2017 and 2018 cropping seasons considering each year-location combination as a different environments. The study carried out with objectives to estimate magnitude of genotype by environment interaction, comparing AMMI and GGE to evaluate stability of genotypes and identifying superior genotypes. We observed significance effects in all sources of combined ANOVA, since the grain yields of all 40 barley genotypes were significantly affected by environment, which accounted for 40.6 % of the total variation, whereas genotype and genotypeenvironment interaction accounted for 21.12 % and 23.07 %, respectively. The two most used methods to analyze GEI and evaluate genotypes are AMMI and GGE Biplot, being used for the analysis of multi environment trials data (MET).Both models were equivalent for the data’s evaluation, but GGE permitting increased reliability in the selection of superior cultivars (Which-won-where pattern) and test environments (discrimitiveness vs. representativeness).Wricke’s ecovalence, Finley-Wilkinson, Shukla’s stability, Lin&Binns cultivar superiority measure, AMMI Stability Value (ASV), and YSI stability analysis measures also used to identify stable genotypes, and G19, G36, G5 are the most stable genotypes in almost the stability analysis measures, since they are superior genotypes with all test environments. While the genotypes G33, G32, G12 and G18 also the instable genotypes in the test environments. GGE Biplot view of relation among test environments of this study showed that; Among the testing environments Hagereselam 2018 is an ideal testing location to identify stable and high yielding genotypes followed by Ayba 2018, since Hagereselam 2018 and Ayba 2018 are most applicable test locations for identifying stable and high yielding barley genotypes for the region. Mean performance and stability of GGE biplot indicated that G24 had the ideal genotype with highest mean yield as well as stability with desirable genotypes G20, G19, G5, G36, while G33 and G30 had the lowest mean yield and less stability genotypes in all the six test environments.
Analysis on utilization of maternal health care service in Ethiopia: Using Ethiopian Mini Demographic and Health survey
(Mekelle University, 2023-11-28) Hiwot Amaha
Background: The World Health Organization (WHO) established the "Safe motherhood package" as a manual for interventions in maternal and child health, and it lists antenatal care as the fundamental intervention in lowering maternal and infant mortality. Antenatal Care for women and children starts with their immediate health issues and extends to their long-term wellbeing as well as the wellbeing of the community. Getting in touch with mothers and identifying and managing present and future risks and issues are the main goals of prenatal care. It is regarded as one of the most crucial for the mother's health, the fetus's optimal development, and preventing or lessening pregnancy complications (Fantahun M, 1992). Methodology: This research used cross sectional study design retrieved from Ethiopian MiniDemographic and Health Survey 2019 to assess factors affecting utilization of maternal health care services in Ethiopia. This study analyzes responses from 3979 women age 15-49, who have at least one child under age five at the time the survey was fielded. Result: Women from Urban areas were more likely to receive ANC care than women from other rural areas. The bivariate results show a significant difference in the use of maternal health care services by age, marital status, women’s education, parity, wealth, religion, and family size as significant and independent predictors for the use of antenatal care. And age, wealth, region, residence, women’s education, parity, religion and family size are significance and independent predictors for the use of delivery care services in Ethiopia. Bivariant and multivariate analysis showed significant association between ANC and maternal age, women’s education, religion and wealth. Age (OR=1.527, 95%CI=1.102,2.116), Education (OR=1.731,95%CI=1.434,2.090), religion (OR=1.829,95% CI=1.386, 2.414), wealth (OR=2.234,95% CI= (1.758, 2.839) and residence (OR=.387,95% CI= 290, .516) were associated with choice of delivery site. Education and parity were found to be strong predictor of both antenatal care and delivery care. Conclusion: In brief, the study discovered low maternal health care utilization in the area. Increasing maternal health service coverage and promotion of IEC in the community are recommended.
Assessment of the physicochemical characteristics of honey collected from Dalocha Woreda, SNNP, Ethiopia
(Mekelle University, 2025-01-25) Getachew Asfaw Melka
Honey is the natural sweet substance produced by honeybees from the nectar of blossoms or from the secretion of living parts of plants or excretions of plant-sucking insects from the living parts of plants. The present study aimed to assess the physicochemical characteristics of honey collected from Dalocha Woreda, SNNP, Ethiopia. The honey samples collected from different Kebele’s of Dalocha woreda were of different colors (red and white honey). The collected samples were analyzed for their pH, free acidity, color, electrical conductivity, moisture content, ash content, specific gravity, water-insoluble solid, reducing sugar, sucrose content, hydroxymethylfurfural (HMF), and some selected metal contents of Zn, Mn, Fe, Ni, Pb, Cr, and Cd. The result of physicochemical analysis showed pH in the ranges of 3.98-4.6, free acidity in the ranges of 16-27 meq/kg, color in the ranges of 66.67-128.67 mmpfund, electrical conductivity in the ranges of 0.29-0.79 mS/cm, moisture contents in the ranges of 17.3-18%, ash contents in the ranges of 0.25-0.41 g/100 g, specific gravity in the ranges of 1.35-1.412, water insoluble solid in the ranges of 0.27-0.6 g/100g, reducing sugars in the ranges of 66.58-77.04 g/100 g, sucrose in the ranges of 2.134-4.29 g/100g, and HMF contents in the ranges of 0.455 4.67 mg/kg. Almost all samples of honey examined were within the acceptable range of Ethiopian standards (ES) and World Health Organization (WHO) standards, except for water insoluble material which was poor mainly due to a lack of appropriate handling during harvesting and storage of the product. However, it was observed that there was a significant difference among these tested parameters for these honey samples. The metal content of the honey samples was also found (in mg/L) Zn in the ranges of 2.07-9.69, Pb in the ranges of ND 0.1, Mn in the ranges of 1.9-6.83, Cr in the ranges of 0.35-0.6, Fe in the ranges of 42.28-61.41, Ni below detection limit (BDL) and Cd BDL. The highest concentration was observed for Fe and the lowest concentrations were observed in Pb, Ni, and Cd. Most trace metals are within the acceptable range set by national and international standards except Pb and Cd contents in some samples that need further study.
ASSESSMENT ON PHYSICOCHEMICAL QUALITY OF TAP AND BOTTLED WATER CONSUMED IN MEKELLE CITY, ETHIOPIA
(Mekelle University, 2025-01-25) Tenagne Jiru Mergia
Water is a vital resource for human survival. Clean drinking water is a basic need for good health. In this study the levels of six heavy metals, nine common ions and five physical parameters in four different brands of bottled water samples and two tap water samples from different sources that are consumed in Mekelle, Ethiopia were investigated. Concentrations of Fe, Zn, Cu, Cr, Pb, Cd, Ca and Mg were determined by atomic absorption spectroscopy. UV – spectrophotometry was used for the determination of common anions (F-, Cl-, NO3-, SO42- and PO43-) and levels of common cations (Na+ and K+) were determined by flame photometry. The mean concentration of Fe, Cu, Zn, Cd, Pb, Na+, K+, Ca2+, Mg2+, F , Cl-, NO3-, SO42-, PO43-, TDS, TH, Turb, EC and pH in water samples were found in the range (0.82-0.9433), (0.39-0.6693), (0.055-0.2027), (0.0147-0.0213), (0.45-0.6567), (1.63 23.55), (0.01-2.75), (0.117-121.7), (0.073-15.33), (0.0019-0.153), (0.81-16.523), (0.15-6.1033), (0.2366-241.67),(0.0186-0.0286), (1.32-641.29), (0.5-365.33)mg/L, (0.01-0.34)NTU, (8.77 898.33)µs/cm and (6.52-7.33) respectively. All the selected heavy metals (except Zn) were not detected in all bottled water samples. All the heavy metals were detected in both tap water samples except Cr which was not detected in tap water sample from Gerebsegen source (GS-1). All common anions (except F- and PO43-) and all common cations were detected in all water samples analyzed. PO43- was not detected in all bottled water samples and F- was not detected in BW1, BW3 and BW4. Common cations (Na+, Ca2+ and Mg2+) and common anions (Cl-, NO3- and SO42-) were found to be higher in BW4 than other bottled water samples. Concentration levels of all the heavy metals and common ions were found to be higher in the tap water samples than bottled water samples. Concentration levels of all common cations (except K+), all common anions (except PO43-) and levels of all heavy metals (except Cu) were found to be higher in tap water sample from Aynalem source (AN-1) than tap water sample from Gerebsegen source. Detected concentrations of Cu, Zn, Cr and all common ions in all water samples analyzed were below the maximum contaminant level proposed by WHO. Concentrations of heavy metals: Fe, Cd and Pb in tap water samples from both sources exceeded the maximum permissible limit set by WHO. Hence all the tested bottled water samples are safe for drinking purpose.
Bayesian Survival Analysis of Adult Tuberculosis Patients: the Case of Lemlem Karl Hospital, Maichew, Southern Tigray.
(Mekelle University, 2024-11-28) Lemlem Tekle
Tuberculosis is an airborne disease caused by the bacterium Mycobacterium tuberculosis, primarily affects the lungs. Transmission occurs through the air when individuals with pulmonary TB are not undergoing proper treatment. This study aimed to identify factors affecting the survival time of adult TB patients in LKH, Maichew, and Southern Tigray. To address the objective of this study, 242 adult TB patients were included in the study based on data taken from the medical records of patients enrolled from July; 2020 to January; 2024. Almost half, 50.4%, of the adult TB patients were female. Kaplan Meier plots were used for comparison of survival function; Bayesian survival models were used to identify factors affecting the survival time of adult TB patients. Of the total patients in the study 178 (73.6%) were censored. The estimated median survival time of patients was 26 months. Bayesian log-normal accelerated failure time model using MCMC and INLA method fit adult TB data better than other Bayesian accelerated failure time models used in this study. The Bayesian log-normal accelerated failure time model using the INLA method was preferable to the MCMC method due to smaller standard error and narrow credible interval. The results of this model show that the survival time of adult TB patients is significantly affected by age, residence, body weight, HIV status, BMI, dose level and cigarette smoking of adult TB patients(pvalue<0.05). Bayesian log-normal accelerated failure time model using the INLA method describes the adult TB dataset well. From the Bayesian result, the risk factors for the survival time of adult TB patients were age group (31 to 45, 𝛾 = 0.8607),(46 to 60, 𝛾 = 0.7189)and( >60, 𝛾 = 0.6637);residence(rural,𝛾 =0.7408); HIV (Positives, 𝛾 = 0.68386); Dose (III, 𝛾 = 0.6570) ,IV 𝛾 = 0.9512),BMI(Overweight, 𝛾 = 0.8607) and (Obese 𝛾 = 0.0779); base line weight(> 50kg, 𝛾 = 0.8693) and (smokers, 𝛾 = 0.8607) at 95% credible interval and those factors were prolonged the timing death of adult TB patients. Therefore, health professionals should focus on the identified factors to improve the survival time of TB patients.
BIODIESEL PRODUCTION FROM CASTOR SEED OIL THROUGH TRANSESTERIFICATION WITH METHANOL USING WASTE CHICKEN EGGSHELL AS A NATURAL HETEROGENEOUS CATALYST
(Mekelle University, 2025-01-25) KINFE GEBREGERGIS GEBREMEDHIN
he depletion of fossil fuel reserves and growing environmental concerns have increased interest in developing renewable and sustainable energy sources. Biodiesel, a clean-burning alternative fuel derived from vegetable oils or animal fats, has emerged as a promising solution to reduce the dependence on conventional diesel. This study investigates the feasibility of producing biodiesel from castor seed oil through transesterification using waste chicken eggshells as a natural heterogeneous catalyst. Castor seed oil was extracted from castor seed using ethanol. The eggshell catalyst was prepared by calcining chicken eggshells at 900°C for 3 hours to obtain calcium oxide. Different proportions of the parameters methanol-to-oil ratio and calcined waste chicken eggshell catalyst were taken during transesterification to produce biodiesel. The castor oil from 100 g castor seed extraction yielded 46% (48.4 ml). The highest biodiesel yield was observed during the transesterification reaction when the methanol-to-oil ratio was 9:1, and catalyst loading was 3 wt.%. Under these conditions, the biodiesel yield reached 81.6%. Three repeatable reactions were taking place using the optimized catalyst (3%) and their deviation became 1.4. This indicates calcined waste eggshell catalyst exhibited reusability, making it a viable option for the industrial-scale production of biodiesel from castor seed oil. The physicochemical properties of castor biodiesel were changed from castor oil ( density from 0.951g/ml to 0.881 g/ml, viscosity from 132 mm2/sec to 10mm2//sec, and acid value from 3.86 to 0.950). The fuel property test confirmed that the transformation of castor oil into castor biodiesel. In the XRD characterization, the strong peak pattern occurred at 2θ =30º corresponding to the miller index (1 0 4) in the uncalcined waste chicken eggshell and completely disappeared at the XRD peak pattern in calcined waste eggshells. The FT-IR spectra of Castor biodiesel showed an absorption band at 1742 cm-1, 1460 cm-1, and 1166 cm-1 that indicates the ester carbonyl group (-C=O), methoxy group(-OCH3). and ester functional group (C-O-C). The GC-MS spectra recognize 98.4% FAME, 0.6% FAEE, and 0.7% acids. This research demonstrates the potential of utilizing castor seed oil and chicken eggshells for the sustainable production of biodiesel, contributing to the development of renewable energy and circular energy.
Characterization of carbonized and uncarbonized bone waste: Physicochemical properties and their potential as alternative energy sources
(Mekelle University, 2025-01-25) Haftu Gebremedhin Gebremariam
One of the significant challenges facing societies today is meeting the growing energy demand for transportation, heating, lighting, and industrial processes, which have a considerable environmental impact. Population growth and urbanization have both directly and indirectly increased energy demand. This study investigates the characterization of carbonized and uncarbonized waste bone, examining their physicochemical properties and potential as alternative energy sources, particularly for use in the cement industry. The research utilized two laboratory techniques: proximate analysis to determine the physical properties and calorific values, and ultimate (elemental) analysis to assess the chemical composition, including hydrogen, carbon, nitrogen, oxygen, and sulfur content of both carbonized and uncarbonized bones. The results indicated that the moisture content, volatile matter, and fixed carbon of carbonized and uncarbonized bones were 1.35% vs. 2%, 55.65% vs. 50.22%, and 2.55% vs. 7.72%, respectively. The calorific values were 3,212.75 kcal/kg for carbonized bones and 4,018.01 kcal/kg for uncarbonized bones. In terms of elemental composition, carbon content was 32.46% for carbonized bones and 38.13% for uncarbonized bones, while nitrogen levels were 0.99% and 1.10%, and sulfur content was 0.18% and 0.078%, respectively. Comparative analysis of greenhouse gas emissions revealed that uncarbonized bones emitted 1.10% nitrogen, 38.13% carbon, and 0.078% sulfur, compared to 9.67% nitrogen, 58.84% carbon, and 0.25% sulfur from coal. The study concludes that uncarbonized bones are more favorable as an alternative energy source compared to carbonized bones, as they offer comparable emissions and higher calorific values. It is recommended that partial replacement of fossil fuels with bone-derived energy could offer both environmental and economic benefits, promoting cleaner, cost-effective energy solutions.
Comparative Assessment of Heavy Metal Levels in the Soil and Some selected Edible Fruits (Orange and Papaya) Grown in the Addiha Irrigational site, Kola Tembien-Woreda Tigray, Ethiopia
(2025-03-25) Gebremeskel Welegebrial Hagos
Edible fruits (orange and papaya) are source of vitamins, minerals and organic acids which provide an excellent health promoting nutrients. Heavy metals are natural constituents of the Earth's crust and their excessive consumption levels can be damaging to the organisms. The objective this study was compartive assessement of heavy metals (Fe, Zn, Cu, Cr and Mn) in the soil and selected edible fruits (Orange and Papaya). The sampling methods of this study were randomly and targeted methods.The chemicals used in this study were HNO3, HClO4, HCl and distilled water and the materials used inthis study were cutters, sample containers (plastic bags), gloves, hot plates, beakers, test tubs, electrical balance, spoon, stirrer, sample cells, oven, sample holder, volumetric flask and digester. The study was assessed heavy metal (Zn, Cu, Cr, Mn, and Fe) in both soil and selected edible fruits (orange and papaya) grown in the Addiha irrigation site Kola Tembien woreda central zone of Tigray, Ethiopia. Soil analysis revealed that Zn, Cu, and Mn were below established WHO (2011) safe limits, while Cr and Fe exceeded them. In contrast, all heavy metal levels in the selected edible fruits (orange and papaya) were below the established WHO (2012) safe limits. T-tests showed statistically significant differences (p<0.05) for the concentration level of heavy metals Zn, Cr, Mn, and Fe, but the heavy metal Cu is not statistically significant (p>0.05), while the analysis using ANOVA showed significance for all elements when comparing soil to fruit which between soil and orange and between soil and papaya were statistically significant differences (p<0.05). Transfer factors between soil and edible fruits (orange and papaya) varied, with Zn being highest in both. Strong positive correlations were also observed between heavy metal levels in soil and those in the selected edible fruits. The correlation coefficients of soil and orange are (0.9877) and soil and papaya is (0.99932). ANOVA revealed statistically significant differences (p<0.05) between orange and papaya fruits for the mean concentration of heavy metals except Cu at (p<0.05) for Zn, Cu, and Fe, but not for Cr and Mn (p>0.05). Furthermore, ANOVA comparisons between orange and soil, as well as papaya and soil, showed statistically significant differences for all heavy metals (Zn, Cu. Cr. Mn and Fe) (p<0.05). Keywords: Heavy metals, Edible Fruits, Soils, Permissible levels
COMPARATIVE STEADY OF EARTH’S MAGNETIC FIELD VARIABILITY, SQ-CURRENTS AND EQUATORIAL ELECTROJET OVER INDIAN, AFRICAN AND AMERICAN SECTORS
(Mekelle University, 2024-12-28) Bogale Fentaye
The earth’s magnetic field during day and night is not the same due to different factors. The sun’s radiation is one of the parameters to influence the variability of the earth’s magnetic field in different sectors. The variation of magnetic field in turn produces huge variation in ionospheric currets such as the Sq- current, Equatorial Electrojet (EEJ), counter electrojets (CEJ). Equatorial electrojet (EEJ) is enhanced current flowing from west to east during day time at dip equator between ±30 latitude at an altitude of about 107 Km. This high concentration of electric current flowing from west to east in a narrow belt flanking the dip equator on the sunward hemisphere has been termed the equatorial electro jet. Our objective is to study , variation of the earth’s magnetic field strength, Sq- current, EEJ and CEJ for African sector and American sector and the Indian sector. The magnetic field strength in the Indian sector is relatively stronger as the geomagnetic equator passes close to southern India, influencing EEJ intensity and variability. While in the African sector, the geomagnetic field is weaker compared to the Indian sector, resulting in higher ionospheric conductivity and often stronger EEJ current, When we come to the American sector the Geomagnetic field is relatively weakest but features a more significant magnetic declination (the angle between geographic and geomagnetic north), particularly in the south America. The declination impacts the electrodynamics, introducing additional east-west variability.
COMPARISON OF RADIO-QUIET AND RADIO-LOUD FAST-WIDE CORONAL MASS EJECTIONS IN SOLAR CYCLE 24
(Mekelle University, 2025-06-21) Haylay Gebrehiwet Assefa
CMEs are complex phenomena associated with solar activity. RQ CMEs lack type II radio bursts in the metric and DH wave lengths,whereas,RL CMEs are associated with metric or DH type II bursts.This thesis focuses on comparing the properties of radio-quiet (RQ) and radio-loud (RL) FW Coronal Mass Ejections (CMEs) during Solar Cycle 24 (2008-2019 ),Using data from multi-instrument and multi-spacecraft sources such as Solar Heliospheric Observatory (SOHO), Solar Terrestrial Relations Observatory (STEREO), and Wind spacecraft. The study begins with a 115 Fast Wide (FW) CMEs, characterized by speeds (V ≥900 km/s) and angular width (W ≥ 600 ), observed during Solar Cycle 24. By utilizing data from LASCO/SOHO, SECCHI/STEREO, and wind/WAVES instruments, we identified 58 RQ CMEs and 57 RL CMEs.The RL CMEs had an average speed of (1415 km/s) compared to (1145 km/s) RQ CMEs.Moreover, RL CMEs also have more acceleration (+34 m/s2) than RQ( +19 m/s2) CMEs. The average width of the RL (3310),CMEs is much larger than the average width of RQ (2000) CMEs. We also found that 38% of RQ CMEs and 28% of RL CMEs come from the NW quadrant, while 19% of RQ CMEs and 30% of RL CMEs come from the NE quadrant.The fraction of full halo CMEs(82.5% ) was largest for the RL CMEs,but smaller for RQ(21%) CMEs. RL CMEs are associated with stronger flares (80% X and M class), whereas RQ CMEs are linked to weaker flares (65% C class and 32.5% M class). RL CMEs are more energetic than RQ CMEs.
Detoxification Effect of Rosemary Leaf Powder on Repeatedly Deep-Fried Hayat Palm Oil for Potato Chip Production
(Mekelle University, 2025-01-25) ASSEFA MIESHO GEBRE
Deep-frying with vegetable oils, particularly Hayat palm oil (HPO), is widespread activity in Tigrai; Northern Ethiopia. However, frequently frying with HPO can generate harmful chemicals to health. Therefore, the purpose of this study was to assess the detoxification effect of rosemary leave powder on HPO used for the preparation of potato chips. Different frying cycles (1st, 3rd, 5th, 7th, and 9th) with and without rosemary powder were employed for frying 500 g of row potato at 180 oC in 2L of Hayat palm oil at different doses of 100,150, 200, 250, and 300 mg/kg rosemary powder for 20 min. Oil samples were taken at 1st, 3rd, 5th, 7th, and 9th frying days. The result of the analyzed physical parameters such as moisture content for fried Hayat palm oil without rosemary (FHPO) was found in the ranges of 0.73 to 1.265% while fried Hayat palm oil with rosemary (FHPOR) varied from 0.19 to 0.538% and specific gravity from 0.8906 to 0.9226% for FHPO and 0.8868 to 0.9121% for FHPOR. The refractive index for FHPO was also recorded from 1.459 to 1.547, but FHPOR was obtained in the ranges of 1.453 to 1.459. The pH values were recorded between 4.058 to 4.57 for FHPO and 4.68 to 5.814 for FHPOR. In addition, the viscosity value also ranged from 73.635 to 88.415 cP for FHPO and 48.214 to 63.741 cP for FHPOR. Among the chemical parameters analyzed, peroxide values ranged from 10.167 to 14.578 meqO2/kg oil for FHPO and 6.463 to 9.8 meqO2/kg oil for FHPOR, iodine values from 57.34 to 53.54 g of I2/100g oil for FHPO, and from 45.55 to 50.465 g of I2/100g oil for FHPOR, acid values from 0.935 to 5.61mg KOH/g oil for FHPO and from 0.186 to 0.7922 mg KOH/g oil for FHPOR, saponification values from 204.5431 to 208.508 mg KOH/g oil for FHPO and 157.129 to 203.977 mg KOH/g oil for FHPOR, conjugated diene values from 3.079 to 4.374 % for FHPO and 0.2869 to 0.6432% for FHPOR. Statistical analyses using one-way ANOVA and Tukey’s test revealed significant differences (p < 0.05) across all studied physical and chemical parameters. GC-MS analysis also confirmed the removal of harmful chemicals such as alcohol, epoxide, ketone, and CDLA from FHPOR while oleic acid present, indicating that the oil had not decomposed. The level of heavy metal concentrations in FHPOR were found within the permissible limits (Pb: 0.01, Fe: 0.10, Cu: 0.10, Cd: 0.01, As: 0.01, Hg: 0.01) mg/100g, while FHPO exhibited higher levels (Pb: 0.10, Fe: 0.02, Cu: 0.11, Cd: 0.12, As: 0.11, Hg: 0.10) mg/100g. In conclusion, the incorporation of rosemary leaf powder into deep-frying practices significantly enhances the chemical profile of HPO by reducing toxicant chemicals and improving its oxidative stability. Generally, the present study showed the potential of rosemary as a natural additive for healthier cooking methods and improved oil quality
Effect of aerobic and anaerobic training on physical, physiological, and hematological variables among middle-distance runners in Ethiopia
(Mekelle University, 2025-05-28) NIGUSSIE GICHAMO
The purpose of the study was to investigate the “Effect of aerobic and anaerobic training on the physical, physiological, and hematological variables of middle-distance runners in Ethiopia”. The selected middle distance male athletes (N=60) were categorized into two aerobic training (N=30) and anaerobic training (N=30) both participated in 800 meters and 1500 meters. Age of participants was 16-18 years and the training program consists of aerobic training and anaerobic training. The duration of the training period was restricted to twelve weeks and the number of sessions per week confined to five. Anaerobic training consists of Speed and strength work outs and aerobic training, such as Endurance work outs. The independent variables are divided into experimental group-1 (Aerobic training) and Experimental group-1I (Anaerobic training). The dependent variables are Physical variables includes Strength (vertical jump), Speed endurance (300mts run), Physiological variables includes Resting heart rate, Systolic Blood Pressure, Diastolic Blood Pressure & VO2 Max and the Hematological Variables includes Red blood cells, Hemoglobin, White blood cells, Hematocrit and Platelets and the Athletic Performance Variable: are 800 meters run and 1500 meters run . In order to test the effect of training, the collected data from all the two groups before and after experimentation on Physical, Physiological and hematological variables were statistically analyzed by using independent t test. In all the cases the level of confidence is fixed at 0.05 to test the significance. The results of the study before and after the aerobic training indicates positive effects in physical variables are speed endurance (0.42) in physiological variables resting heart rate (1.96), Systolic Blood Pressure (3.6), Diastolic Blood Pressure (6.44) in hematological variables white blood cells (2.57) and hematocrit (0.29). The negative effects are in physical variables is vertical jump (-3.66) in physiological variables only vo2 max (-1.63) in hematological variables red blood cells (-0.08), hemoglobin (-0.57) and platelets (-8.36). The results in physical, physiological and hematological variables before and after the anaerobic training undergone shows positive effects in physical variables are speed endurance (1.13) in physiological variables no variables has positive effects in hematological variables hemoglobin (0.21) only have positive effects. The negative effects are in physical variables is vertical jump (-2.4) in physiological variables resting heart rate (-0.73), Systolic Blood Pressure (-38.9), Diastolic Blood Pressure (-3.33) and vo2 max (-0.92) in hematological variables red blood cells (-0.36), white blood cells (-0.07), hematocrit (-1.13) and platelets (-27.63.It is concluded that after the two training methods, the physical, hematological and physiological variables indicated differences among the groups. Finally, the study would provide useful guidelines for coaches, managers and athletes to consider appropriate physical fitness, physiological and hematological markers by applying these types of quantified aerobic and anaerobic training methods
EFFECT OF COOPERATIVE LEARNING ON STUDENTS’ ACADEMIC ACHIEVEMEN IN CHEMISTRY ON THE TOPICS OF CHEMICAL EQUILIBRIUM AND PHASE EQUILIBRIUM: THE CASE OF KELLEM PREPARATORY SCHOOL, KELLEMWOLLEGA ZONE, OROMIA REGIONAL STATE, ETHIOPIA
(Mekelle University, 2025-01-25) GUTA DEGU DISASA
The study investigate effects of cooperative learning on students’ academic achievement in chemistry on the topics of chemical equilibrium and phase equilibrium: The case of Kellem preparatory school, Kellem Wollega zone, Oromia regional state, Ethiopia. The study sampled 120 students from two sections one taken as experimental group and the other as control group which are purposively selected from six sections of Kellem Preparatory School grade 11 natural science because of relatively low score in chemistry. The data obtained from 60 students (M=29 and F=31) participated in cooperative learning instruction methods and 60 students (M=30 and F=30) participated in instruction based on regular learning methods, 2 School administrators and 2 Chemistry teachers. The research was used experimental methods, questionnaire and interview for data collection. Data analysis was done descriptively using mean, frequencies, percentages and t-test. A pre-test was administered before the study to identify students’ prior knowledge. Sample students score an average academically achievements 60.12% of control group (M=30.06% and F=30.06%) and 60.4% of experimental group (M=29.20% and F=31. 20%) before the treatment. A post- test was administered after cooperative learning instruction methods in order to examine the difference in achievements. In the comparison of the post –test of the two groups, the experimental groups were an average of 81.44 % (M=39.36% and F=42.08%) of academic achievements and 62.52% of control group (M=31.26% and F=31.26%) academic achievements in selected topic. The result of study show that cooperative learning instructional methods was better than the regular method of instructional methods in increasing students’ academic achievements and promote face to face interaction, creating positive dependence and insuring the active participation of all students in activities.
EFFECT OF THE ENSO PHASES ON RAINFALL VARIABILITY OVER THE NORTHERN HIGHLANDS OF ETHIOPIA
(Mekelle University, 2025-06-21) SETEGN WALELIGN
This study investigates the effects of the El Niño-Southern Oscillation (ENSO) phases on rainfall variability over the Northern Highlands of Ethiopia, focusing on four key stations—Debre Birhan, Kombolcha, Woldia, and Lalibela—from 2011 to 2020. Utilizing descriptive statistics, Mann-Kendall trend tests, Sen’s slope estimator, and correlation analyses, the research evaluates seasonal (Belg, Kiremt, and Bega) and monthly rainfall patterns in relation to ENSO events. The results reveal significant regional variability in rainfall responses to ENSO phases. During El Niño years, Belg rainfall decreases notably in Woldia (-31.3%) but increases in Lalibela (+40.4%), while Kiremt rainfall declines in Debre Birhan (-8.1%). Conversely, La Niña years enhance Belg rainfall across all stations, with Woldia experiencing a 32.7% increase. Time series analysis indicates upward rainfall trends in Debre Birhan (+8.6 mm/year) and Lalibela (+10.5 mm/year), linked to intensified Kiremt rains, whereas Woldia faces declining Belg rainfall (-14.2 mm/year), threatening earlyseason agriculture. The study underscores ENSO’s critical role in modulating rainfall variability, with implications for agriculture and water resource management. Positive trends in Lalibela and Debre Birhan suggest opportunities for improved crop yields, while Woldia’s rainfall decline highlights vulnerabilities requiring adaptive strategies such as drought-resistant crops. These findings advocate for localized climate adaptation policies to mitigate ENSO-induced risks and leverage favorable rainfall patterns in Ethiopia’s highlands.
Green Synthesis of Copper Oxide Nanoparticles (CuONPs) using Clematis simensis, Characterization and their Antibacterial Activity against MultiDrug Resistant Bacteria
(Mekelle University, 2025-06-28) Alem Gebrehawerya Reta
Recent advancements in material science and green nanotechnology have led to the development of bioinspired nanoparticles, which offer promising alternatives for combating multidrugresistant bacteria, a major public health concern. The unique, antibactericidal properties of CuONPs offer invaluable possibilities for combating multidrug-resistant bacterial infections. In the present study, copper oxide nanoparticles were synthesized by a cost-effective, eco-friendly, and single-step method using ethanolic leaf (ET) extract of clematis simensis (CS) acting as a reducing agent. CS-CuONPs and ethanolic leaf extract were characterized by UV-Vis, FT-IR, GC-MS, XRD, DLS, SEM, and TEM. UV-Vis spectrum showed a characteristic peak at 286 nm, indicates the formation of CS-CuONPs. Phytochemical, GC-MS, and FTIR analysis of ethanolic leaf extract of C. simensis revealed the presence of polyphenolic compounds, flavonoids, and their related bioactive compounds like Eugenol and methyl eugenol, with the broad peak 3599.77 cm-1 indicating the OH functional group responsible for reducing, capping, and stabilizing agents in the synthesis of CS-CuONPs. The XRD diffractogram proved the existence of a crystalline structure of CS-CuONPs with an average size of 22.7 nm, and the DLS analysis of CS-CuONPs was -28.3 mV, which confirms moderate stability and high surface negative charge. SEM and TEM analysis revealed that the CS-CuONPs were predominantly pseudo-spherical with some irregular shapes, and had an average particle size of 22.65 nm.The CS-CuONPs have shown strong antibacterial activities against the tested Gram-positive bacteria B. subtilis, with the highest zone of inhibition of 30±0.4 mm and minimum inhibitory concentration of 100µg/mL. In addition, E. faecalis and K. pneumoniae showed moderate susceptibility with the zone of inhibition of 20±0.2 mm for both bacteria in comparison with Positive controls (Ciprofloxacin). The results suggest that clematis simensis, with its rich phytochemical profile, enhances nanoparticle stability and antibacterial efficacy. Therefore, CSCuONPs show potential as an effective alternative for combating MDR bacteria.