SINET: Ethiopian Journal of Science

Adsorption of Hexavalent Chromium on KOH Activated Carbon Derived from Water Hyacinth Leaf Coated with Polyaniline/Polypyrrole

Asmamaw Taye — 2024-03-27

KOH-Activated carbon derived from Water Hyacinth (KOH-WHL-AC) was prepared and coated with Polyaniline-Polypyrrole (PANI/PPY) copolymer for the removal of hexavalent chromium (Cr(VI)) from wastewater. The prepared material was characterized by FT-IR and XRD. The effect of pH, contact time, dosage, and initial Cr(VI) concentrations were optimized using batch adsorption experiment. The adsorption kinetics was found to fit better to pseudo-second-order than the pseudo-first order model. Langmuir and Freundlich isotherm models were analyzed using linear fitting. It was found that the Langmuir adsorption model gives the best fit indicating that the monolayer adsorption of Cr(VI) on the KOH-WHL-AC. The highest adsorption capacity of 409.83 mg/g was achieved at pH 1.0, and equilibrium was achieved within 420 min. The reuse efficiency of the synthesized material was also found to be greater than 54% for five consecutive cycles. Thermodynamic studies have also been carried out and the adsorption was found to be spontaneous and endothermic

DNN-based Multilingual Acoustic Modeling for Four Ethiopian Languages

Solomon Teferra — 2024-03-27

In this paper, we present the results of experiments conducted on multilingual acoustic modeling in the development of an Automatic Speech Recognition (ASR) system using speech data of phonetically much related Ethiopian languages (Amharic, Tigrigna, Oromo and Wolaytta) with multilingual (ML) mix and multitask approaches. The use of speech data from only phonetically much related languages brought improvement over results reported in a previous work that used 26 languages (including the four languages). A maximum Word Error Rate (WER) reduction from 25.03% (in the previous work) to 21.52% has been achieved for Wolaytta, which is a relative WER reduction of 14.02%. As a result of using multilingual acoustic modeling for the development of an automatic speech recognition (ASR) system, a relative WER reduction of up to 7.36% (a WER reduction from 23.23% to 21.52%) has been achieved over a monolingual ASR. Compared to the ML mix, the multitask approach brought a better performance improvement (a relative WERs reduction of up to 5.9%). Experiments have also been conducted using Amharic and Tigrigna in a pair and Oromo and Wolaytta in another pair. The results of the experiments showed that languages with a relatively better language resources for lexical and language modeling (Amharic and Tigrigna) benefited from the use of speech data from only two languages. Generally, the findings show that the use of speech corpora of phonetically related languages with the multitask multilingual modeling approach for the development of ASR systems for less-resourced languages is a promising solution.

The moderating impact of organizational culture on information security compliance

Kibrom Ejigu — 2024-03-27

This research paper investigates the association between organizational culture and employees' compliance with information security policies. Drawing upon rational choice theory (RCT) and the competing values framework (CVF), our study explores the moderating effects of cultural dimensions on information security compliance in a diverse range of organizations. We employ a scenario-based approach and analyze the data using Partial Least Squares Structural Equation Modeling (PLS-SEM). Our findings underscore the robustness of the model and emphasize the pivotal role of cultural dimensions in influencing employees' compliance intentions.

The study contributes by synthesizing non-fear-based deterrence theory with organizational culture theory, offering practical insights for information security managers. Recommendations include framing compliance as a moral duty, involving end-users in policy development, utilizing effective communication, implementing monitoring systems, and fostering a consistency culture. For organizations, the research underscores the importance of cultivating an ethical culture, emphasizing moral beliefs, and leveraging cultural dimensions to enhance compliance intentions.

Acknowledging limitations related to single-country data collection, a focus on compliance intentions, and the selection of organizations with established policies, this research paves the way for future studies. Future research should aim to replicate this study in diverse cultural settings, consider individual-level culture measurement, and explore additional moderating factors. This research contributes to understanding the intricate relationship between organizational culture and information security compliance, offering actionable insights for practitioners and prospects for further exploration in the information security field.

Assessment of Drinking Water Quality from Source to Household Storage Containers in Kachisi town, West Shewa, Ethiopia

Gazahagn Kebache — 2024-03-27

A wide range of human and natural processes affect the quality of fresh waters and diseases related to contamination of drinking water constitute a major burden on human health. Thus, this study was conducted to assess the quality of drinking water supplied to Kachisi town using selected physicochemical and bacteriological parameters. A total of 60 water samples in triplicate were collected from boreholes, water reservoirs, household taps and storage containers in the households between October, 2019 and February, 2020. The physiochemical parameters were measured using HACH HQ440d multi meter and portable digital spectrophotometer (DR/6000) according to HACH instruction and bacteriological parameters were analyzed using the membrane filtration technique. The study results indicated that temperature and pH of the water samples were in the range of 18.77⁰C and 21.4⁰C, and 7.05 and 7.73, respectively. Total dissolved solids fell between 93 mg/l and116 mg/l while electrical conductivity records ranged between 185µS/cm and 232 µS/cm. The concentrations of Iron, nitrate and phosphate were in the range between 0.01-0.26 mg/l, 2.20-5.72 mg/l and 0.12-0.76 mg/l, respectively. Total Coliforms loadalso varied from 1CFU/100ml to 2CFU/100ml in samples collected from boreholes and reservoirs, from 1CFU/100ml to 12CFU/100ml in tap water samples and from 6CFU/100ml to 22CFU/100ml in samples from storage containers in the households. Fecal Coliform was negative in the water samples collected from boreholes, reservoirs and household taps while it was detected in 25% of the samples collected from household storage containers in the rangeof 3CFU/100ml to 5CFU/100ml. The detection of Total Coliforms in all water samples and Faecal Coliforms in some of the household containers samples might be attributed to absence of disinfection, lack of regular supervision of the system, poor water management and lack of safe water storage and handling practices.

Milk Protein Genes Polymorphism in Indigenous and Crossbred Cattle from a private Dairy Farm in Ethiopia

Rebecca Tewodros — 2024-03-27

Kappa casein and beta lactoglobulin genes are major milk proteins which have a direct effect on protein content in dairy cattle. Molecular-based selection through the identification of genetic polymorphism of major protein genes can be used to gain genetic improvement of milk protein yield. The objective of this study was to identify kappa casein (CSN3) and beta lactoglobulin (LGB) genes polymorphisms in indigenous and crossbreed cattle. A total of 90 whole blood samples were collected from individual animal in a private dairy farm. DNA extraction and quality assessment were done salting out procedure and gel electrophoresis, respectively. Polymerase chain reaction (PCR) was performed with gene specific primers. For genotyping, PCR products of CSN3 gene was digested with HinfI and HindIII while LGB gene was digested with HaeIII restriction enzymes. Two haplotypes A and B; three genotypes, AA, AB and BB were observed at CSN3 of HinfI site and LGB HaeIII site, but only AA and AB were observed at CSN3 of HindIII site in crossbred and indigenous cattle populations. However, at CSN3 locus, A allele was found to be more common (0.65) in indigenous cattle than the B allele (0.35), while B (0.51) allele and AB genotype (0.81) were more frequent in crossbred cattle. But, LGB B allele was higher in indigenous cattle (0.67) compared to Allele A (0.33). LGB BB genotype (0.57) is higher followed by AA genotype in indigenous cattle while both allele and genotypic frequencies are equal in crossbred cattle. Both CSN3 and LGB loci were polymorphic in studied populations. Expected heterozygosity was higher in crossbred (0.49, 0.50) than in indigenous (0.38, 0.33) cattle at CSN3 and LGB locus, respectively which might be due to breed variation. The current findings showed that both CSN3 and LGB genes could be promising diagnostic markers in selecting dairy cattle breed. However, further investigations with large sample size and association study with milk composition is required to substantiate the current result.

The Effect of Global and Local Chemical Reactivity Descriptors in the Determination of Properties of Transition Metal Clusters

Habte Dulla — 2024-03-27

Recently, research on material properties has got lots of attention because of their promising technological applications. In this paper, the author’s focus is on the global and local chemical reactivity descriptors of some transition metal clusters. In addition, the author also include findings of chemical properties with reactivity descriptors. Furthermore, according to Thomas–Fermi approximation and from the exact formulation of Density Functional Theory by Hohenberg and Kohn’s theorem, the author introduce electronegativity and the theory of hardness and softness for further investigation of chemical properties of the clusters. As a part of investigations, the author also introduce the Fukui functions with an emphasis for the determinations of chemical reactivity descriptors. All the results are obtained by theoretical investigation of electronegativity), Chemical potential (), chemical hardness (), and polarizability () of the given transition metal clusters (Cr and Mn). From the results, the author observed that the ionization potential of the clusters increases with decreasing cluster size as the clusters become more stable and tend towards chemical inertness. In conclusion, determination of the reactivity descriptors of the transition metal clusters show results that are in line with previous experimental and theoretical findings.

Boosting First-year Undergraduate Student Motivation for physical fitness workouts through Quality Instruction: A Study at Bahir Dar University

Demissie Gashu — 2024-03-27

There is a relationship between quality physical fitness instruction and motivation of students for its workouts. However, the degree that quality physical fitness instruction predicts the motivation of students' for its workouts is not examined. The purpose of this study was to examine the extent that quality physical fitness instruction to predict the motivation of first-year undergraduate students for physical fitness workouts. For this, the study used a cross-sectional survey design, collecting quantitative data. The sample included 323 students from 32 sections at Bahir Dar University, Ethiopia, who volunteered to participate in the study. The study used adapted standardized questionnaire for assess the motivation of students and quality of physical fitness instruction. The analysis involves Pearson correlation and multiple linear regressions. The correlation results indicate students' motivation for attending physical fitness course workouts is strongly and directly associated with most quality physical fitness service variables (p<.01). In this study, the regression analysis confirmed that students' identified regulation and external motivation for physical fitness course workouts was moderately (26.7%), 16% and 10.7% predicted by quality physical fitness instructional service variables (p<.05). This finding suggests that providing high-quality fitness instruction is crucial for enhancing student motivation in exercise programs within higher education contexts.

Effects of Inulin and Mannan-oligosaccharide on growth, feed utilization, fatty acid profiles, and intestinal morphology of Chamo strain Nile tilapia (Oreochromis niloticus) fry reared under suboptimal temperature

Tewodros Abate — 2024-03-27

The effects of inulin and mannan-oligosaccharide (MOS) on growth, feed utilization, fatty acid profiles, and intestinal morphology of Chamo strain Nile tilapia (Oreochromis niloticus) fry reared at suboptimal temperature were investigated in this study. Chamo strain Nile tilapia is a local strain in Ethiopia that has been selected for fast growth and disease resistance under tropical conditions. However, its performance under cold stress or sub-optimal temperature is unknown. Four experimental diets were formulated to contain 0% (control), 5 g kg^-1inulin, 6 g kg^-1MOS and a combination of 2.5 g kg^-1inulin and 3 g kg^-1MOS. Each diet was fed to triplicate groups of Nile tilapia fry (initial weight 1.6 ± 0.074 g) for nine weeks at a suboptimal temperature of 22.88 ± 0.48 ^oC. The results showed that prebiotic supplementation did not significantly affect the survival, final weight, weight gain, SGR, FCR and ash content of the fish except for the slight improvements observed with MOS alone and in combination with inulin. However, MOS alone or a combination with inulin improved the villi length and width, and some PUFA levels of the fish compared to the control group. The fish fed with the combination of inulin and MOS had the highest crude lipid content and villi length in the proximal and middle intestine among all groups. The fish fed with MOS alone had the highest villi width and some PUFA levels among all groups. These results suggest additions of these prebiotics have improved the villi length and width, and some PUFA levels of Chamo strain Nile tilapia and could be used as sustainable additive in tilapia nutrition under suboptimal temperature conditions Therefore; further studies are needed to optimize the prebiotic supplementation for Nile tilapia under different conditions.

Biology and host preference studies of Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) in Ethiopia

Tesfaye Hailu — 2024-03-27

The fall armyworm (FAW), Spodoptera frugiperda, was first reported on the African continent in early 2016 and reported from Ethiopia in early 2017. The host preference and its biology are not known in Ethiopia. Therefore, the current study was aimed at studying the biology and host preferences of FAW. The experiment was carried out in the greenhouse and wire-house of Ambo Agricultural Research Center from July 2021 to October 2021. The biology of FAW was studied using maize, sorghum, chickpeas, barley, and wheat. The experiments were conducted in the average rearing room temperature of 25.5°C to 37.4°C and relative humidity of 35.33% to 45.46%. Data on egg incubation period, pre-pupal, pupal, egg to adult period, pupal weight, sex ratio, and cannibalism percentage were collected for the biology study. The egg incubation period was between 5 and 8 days. The larval developmental period completed in 14 to 19 days, while pupal stage needed 8 to 9 days. FAW females lay 32-122 eggs in their lifetime. The oviposition period was 2 to 3 days. FAW life cycle ranged from 31 to 38 days at the specified temperature and relative humidity. In terms of the sex ratio of FAW, there was no difference between the tested crops. However, significant (P<0.05) variation was observed with respect to larval cannibalism when reared on different crops. The host preference study was carried out using choice and no-choice experiments on 23 different crops. Data on preferences for oviposition by adult females and for larval feeding were collected. Compared to the other studied host crops, it was discovered that maize, sorghum, swiss chard, teff, elephant grass, and cabbage were the most preferred hosts for larval development and egg laying. The adult female laid eggs on faba bean, soya bean, haricot bean, garlic, and mustard plants, but the eggs did not hatch into larvae. These findings have important implications for understanding the FAW survival, development, and host preference, as well as knowing the best time to plan its effective management.

Primary Submaximal Ideals in Commutative Weak Idempotent Rings

Tamiru A. — 2024-03-27

Let R be a commutative weak idempotent ring (cWIR, for short) with unity, N and be the set of all nilpotent and idempotent elements of R respectively. In this paper, we study the structure of primary submaximal ideals in R and prove that, if P is a primary submaximal ideal of R and for some , then is a maximal ideal of R and , where .

Congruences and Filters of BH-Lattices

K Venkateswarlu — 2024-03-27

In this paper, we introduce the concept of filters in BH-lattices and furnish certain examples. We obtain certain basic properties of BH-lattices. Further, we characterize the filter generated by a given sub set of a BH-lattice. Also we prove that, the set of all filters with set inclusion forms a Heyting algebra. We obtain a one to one correspondence between the set of congruences and filter of BH-lattices.

The Hidden World of Insect-Plant Interactions: a review

Diriba Fufa — 2024-03-27

This review examines the hidden world of plant-insect interactions by emphasizing on the sensory perception and behavior of phytophagous insects, nutritional influence on insect reproduction, host plant resistance, Insects, weed and crop interaction, Insect pollinator plant interaction, tri-trophic interaction, and insect biotechnology. It explores how insects use sensory cues to forage for food, find mates, perceive dangers, and navigate their environment. It also examines the influence of host plants on insect behavior and the use of chemical cues for communication. The potential use of semio-chemicals in pest management for sustainable agriculture is highlighted. Nutritional factors and their impact on insect reproductive success are also discussed, emphasizing the need for balanced diets. The different categories of host plant resistance and their effects on insects are examined. The interdependent relationships between insects, plants, and weeds in agricultural ecosystems are explored, with a focus on the role of insect pollinators. The decline of insect pollinators and the importance of studying them are emphasized. The importance of tri-trophic interactions in maintaining ecological balance and biodiversity is discussed. Moreover, the role of biotechnological techniques like genomics, proteomics, transcriptomics, and epigenetics in understanding insect plant interactions as well as developing insect pest control strategies is discussed. The potential use of natural products produced by plants in environmentally friendly pest control methods is also examined. Overall, this review provides a comprehensive exploration of insect-plant interactions and the potential for sustainable pest control methods.