Development of Maize Stalk Cellulose Fiber Reinforced Calcined Kaolinite Clay Geopolymer Composite

In recent years the popularity of ecological and renewable materials has grown. Aware of the availability of local resources and economic grounds, the attention is paid to the development geopolymer composite. Geopolymers are inorganic polymers that are formed by the polymerization reaction of silico-aluminate and silico-oxide. The aim of the research was to develop single maize stalk cellulose fiber reinforced calcined kaolinte caly based geopolymer composite. Kaolinite clay was characterized for its chemical composition from two different sites located in Ethiopia to use as precursor material. In addition to that, single maize stalk fiber was extracted from the maize stalk local variety by using a retting process, sodium hydroxide purity 98 % used for chemical treatment of the fiber for 30 minutes and its tensile strength 1184 Mpa and young modulus 16 Gpa were determined based on AST M D3822 to use as reinforcement. Sodium hydroxide and sodium silicate in appropriate ratio were used as an alkaline activator. Therefore,  the geopolymer composite developed from chemical treated short single maize stalk cellulose fiber and calcined kaolinite clay based geopolymer matrix activated by sodium water glass.  Geopolymer composites reinforced with 0 weight%, 0.1 weight%, 0.2 weight%, 0.6 weight%, and 1 weight% maize stalk single cellulose were prepared and tested for compression strength according to AST M C 1424. Measured compression strength ranged from 16 Mpa up to 27 Mpa. The result shows that the appropriate addition of single maize stalk cellulose  fibers can improve the Compression strength of a calcined kaolinite based geopolyme

Flexural Strength and Porosity of NaOH-Treated Maize Stalk Cellulose-Fibers-Reinforced Geopolymer Composites

This study characterizes the flexural strength and porosity of NaOH-treated maize stalk cellulose-fibers-reinforced geopolymer composites. Flexural strength tests are conducted, and the fracture surfaces of the composite and geopolymer powder are observed using a scanning electron microscope (SEM). Moreover, porosity analysis is also performed using Image J software from SEM images. The formation of geopolymer is confirmed using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The addition of 1.5 wt% of NaOH-treated maize stalk cellulose fibers improves flexural strength by 2.4 times. The results show that the main failure mechanisms, namely fiber breakage, fiber pullout, and debonding of the fiber and matrix, can increase flexural strength and reduce failures during service life. During the analysis for fiber and particle pullout, SEM images under 25^2 pixels of pore areas are not considered, and an average porosity of 36.7% is achieved

Knowledge, Attitude and Practice of Antenatal Care Service among Married Women of Reproductive Age Group in Mizan Health Center, South West Ethiopia

Back ground: Antenatal care is a medical and general care that is provided to pregnant women during pregnancy. In Ethiopia as well as in the world maternal mortality is high. Mostly this occurred due to pregnancy related complication because of lack of ad equate antenatal care service. Objective: To assess the level of knowledge, attitude and practice of mothers towards antenatal care service in Mizan health center. Methods:  Institutional based descriptive cross sectional study was conducted among married women of reproductive age group who came to Mizan health center from May to August 2014. A Total of 255 women were selected based on systematic random sampling technique after estimating the number of women who came to Mizan health center and they were interviewed by using interviewer administered questionnaire. The data was entered in to Epidata 3.1 and exported to SPSS version 17 for analysis. Finally descriptive analysis was done and data was presented by using tables. Result:  Majority (88.2%) of women know about antenatal care and the rest (11.8%) do not know about antenatal care.   About 70.6% of the respondents wanted to follow antenatal care and the remaining 29.4% of women do not want to follow antenatal care if they get pregnant due to negative attitude.  Less than half (47.9%) of women practiced antenatal care follow up during their pregnancy time. Conclusion: Knowledge and attitude of women towards antenatal care was comparatively in better position. But the practice of women was poor. Further research was recommended to identify factors which are associated with practice. Keywords: knowledge, attitude, practice, antenatal care, Miza

Population dynamics of the Nile tilapia (Oreochromis niloticus L. 1758) stock in Lake Langeno, Ethiopia

Nile tilapia, Oreochromis niloticus, is a widely distributed and economically most import fish species in Ethiopia. Effective management is essential to sustain their fisheries and the benefits for the local communities. However, little is known about the population dynamics of the Nile tilapia stock in Lake Langeno. Vital parameters of its population were determined using length frequency data collected from 5,949 specimens ranging from 8.5 to 35.7 cm total length (tl). These specimens were collected from August 2017to July 2018. The population parameters were determined using the elefan I routine in FiSAT software. Estimated von Bertalanffy growth parameters were asymptotic length (L∞) = 35.70 cm, growth curvature (K) = 0.32 yr-1, age at length zero (to) = -0.49, and growth performance index (Փ') = 2.61. Instantaneous total mortality (Z), natural mortality (M), and fishing mortality (F) rates were determined from length-converted catch curve and empirical models, respectively, and their values obtained were Z = 2.31 yr-1, M = 0.82 and F =1.56 yr-1, respectively. The exploitation rate (E) of Nile tilapia computed from its mortality rates was 0.67 yr-1, suggesting state of overfishing. The size at first capture (Lc) was estimated at 14.0 cm which is much lower than the size at first maturity (Lm=16.62 cm), which further substantiated the state of overfishing. The results of the study are very useful for fishery managers and scientists who wish to manage and further explore the Nile tilapia stock in Lake Langeno

Registration of Tagasaste (Chamaecytisus palmensis) Variety "Lattuu" for the Highland Areas of Ethiopia

አህፅሮት ከዚህ በፊት የተለቀቀውን ዝርያ (MoA) ጨምሮ አስራ አምስት የታጋሳስቴ ዝርያዎች ያላቸው የመኖ ምርት፣ የመኖ ጥራት፣ በሽታን የመቋቋምና ሌሎች ከምርታማነት ጋር የተያያዙ ባህሪያትን ለመገምገም የምርምር ስራው በሆለታና በጀልዱ የምርምር ጣቢያዎች ላይ ለአራት ዓመታት (2008-2011 እኤአ) ተካሄዶ ነበር፡፡ ከእነዚህ ዝርያዎች ውስጥ ሶስት የተሻሉ ዝርያዎች ( CI-15052፣ CI-17497፣ እና CI-15039) ተመርጠው በሆለታ፣ በቁሉምሣና በጀልዱ የምርምር ጣቢያዎች ላይ እኤአ በ 2017 የማረጋገጫ ጥናት ተካሂዷል፡፡ ለቱ (CI-15052) ተብሎ የተለቀቀው አዲሱ የታጋሳስቴ ዝርያ ከፍተኛ የሆነ የሚበላ የመኖ ምርት (7.46 ቶን በሄክታር) ሲሰጥ CI-15039 የተባለው የታጋሳስቴ ዝርያ ደግሞ ዝቅተኛ (3.60 ቶን በሄክታር) የሚበላ የመኖ ምርት ሰጥቷል፡፡ ከዚህ በፊት የተለቀቀው የታጋሳስቴ ዝርያ (MoA) ከሌሎች እጩ ዝርያዎች ጋር ሲወዳደር በተቃራኒው ከፍተኛ የሆነ የማይበላ የመኖ ምርት (6.40 ቶን በሄክታር) ነበረው፡፡ ታጋሳስቴ የሚበላና (ቅጠልና የሚበላ ቅርንጫፍ) የማይበላ (ግንድ) የተክል ክፍል ያለው ሲሆን ለቱ ተብሎ የተለቀቀው ዝርያ በትክክለኛው ጊዜ ከታጨደ 61 ፐርሰንቱ የሚበላ ሲሆን 39 ፐርሰንቱ ግን የግንድ ክፍል ስለሆነ የማይበላ ነው፡፡ የተለቀቀው ለቱ ዝርያ 7.46 ቶን በሄክታር የሚበላ የመኖ ምርት፣ 1.64 ቶን በሄክታር የክሩድ ፕሮቲን ምርትና 3.99 ቶን በሄክታር የሚፈጭ የመኖ ምርት ሰጥቷል፡፡ ለቱ ዝርያ ከዚህ በፊት ከተለቀቀው ዝርያ ጋር ሲወዳደር 24.63 ፐርሰንት የክሩድ ፕሮቲን ምርትና 10.33 ፐርሰንት የሚፈጭ የመኖ ምርት ጭማሪ ነበረው፡፡ በአጠቃላይ የተለቀቀው ለቱ ዝርያ የተሻለ የሚበላ የተክል ክፍል፣ ክሩድ ፕሮቲን እና በእንስሳት ሆድ ውስጥ በተሻለ ሁኔታ የመፈጨት ባህሪያት ነበሩት፡፡ ስለዚህ በብሔራዊ የዝርያ አፅዳቂ ኮሚቴ ዝርያዎቹ ያላቸው የምርታማነት ሁኔታ  እኤአ በ2017 በመስክ ላይ ከተገመገመ በኋላ እኤአ በሚያዝያ 2018 ለቱ የተባለው ዝርያ ለደጋማ አከባቢዎች እንዲለቀቅ የተወሰነ ሲሆን ዘሩን በሆለታ ግብርና ምርምር ማዕከል ይገኛል፡፡      Abstract   Fifteen tagasaste varieties including the standard check variety (MoA) were evaluated for forage dry matter yield, nutritional profiles, disease and insect pest reaction, and other agro-morphological characteristics at Holetta and Jeldu research sites during the main cropping seasons of 2008-2011. Based on the overall performance, three best performing varieties (CI-15052, CI-17497, and CI-15039) were selected and verified with the standard check at Holetta, and Kulumsa Agricultural Research Centers and Jeldu sub-site in 2017 cropping season. The overall mean result indicated that the released variety Lattuu (CI-15052) produced the highest edible yield (7.46 t/ha) while variety CI-15039 produced the lowest (3.60 t/ha) edible yield when compared with other varieties. On the other hand, the standard check variety (MoA) produced the highest (6.40 t/ha) inedible yield. The tagasaste varieties comprise edible (leaf and edible branch) and inedible (stem) plant parts; however, the share of the edible part (61%) of the released Lattuu variety was much higher than its inedible (39%) part of the plant. The total edible dry matter, crude protein, and digestible yields of the Lattuu variety were 7.46, 1.64, and 3.99 t/ha, respectively. Moreover, the released Lattuu variety had 24.63 and 10.33% CP yield and digestible yield advantages over the standard check variety, respectively. Generally, the released Lattuu variety had relatively better leaf to stem ratio, CP, and IVOMD advantages over the standard check variety. Therefore, the national variety releasing committee evaluated the varieties at field conditions in October 2017 and variety Lattuu (CI-15052) was officially released in April 2018 for the highland areas and similar agro-ecologies of the country. The pre-basic and basic seeds of the released Lattuu variety are maintained by the feeds and nutrition research section of Holetta Agricultural Research Center

Ecological status as the basis for the holistic environmental flow assessment of a tropical highland river in Ethiopia

There is an increasing need globally to establish relationships among flow, ecology, and livelihoods to make informed decisions about environmental flows. This paper aimed to establish the ecological foundation for a holistic environmental flow assessment method in the Gumara River that flows into Lake Tana in Ethiopia and the Blue Nile River. First, the ecological conditions (fish, macro-invertebrate, riparian vegetation, and physicochemical) of the river system were characterized, followed by determining the hydrological condition and finally linking the ecological and hydrological components. The ecological data were collected at 30 sites along the Gumara River on March 2016 and 2020. River hydrology was estimated using the SWAT model and showed that the low flow decreased over time. Both physico-chemical and macroinvertebrate scores showed that water quality was moderate in most locations. The highest fish diversity index was in the lower reach at Wanzaye. Macroinvertebrate diversity was observed to decrease downstream. Both the fish and macroinvertebrate diversity indices were less than the expected maximum, being 3.29 and 4.5, respectively. The normalized difference vegetation index (NDVI) for 30 m and 60 m buffer distances from the river decreased during the dry season (March–May). Hence, flow conditions, water quality, and land-use change substantially influenced the abundance and diversity of fish, vegetation, and macroinvertebrate species. The pressure on the ecology is expected to increase because the construction of the proposed dam is expected to alter the flow regime. Thus, as demand for human water consumption grows, measures are needed, including quantification of environmental flow requirements and regulating river water uses to conserve the ecological status of the Gumara River and Lake Tana sub-basin

Porous Maize Stalk Cellulose Fiber-Reinforced Geopolymer Composites for Heat Insulation at the Bottom Side of a Local Electric Stove

The objective of this work is to develop porous maize stalk cellulose fiber-reinforced geopolymer composites for heat insulation on the bottom side of an electric stove using the solid impregnation method. Heat loss measurement is conducted using an infrared thermometer. Moreover, the temperature effect on the composites is investigated. The maize stalk cellulose fibers are very essential to anticipate the cracking phenomenon generated by high temperatures. The degradation of the fibers causes the formation of small cavities in the matrix, and thus leads to high temperatures. The experimental result shows that it takes 22 minutes to boil water using the proposed electric stove, whereas it takes 29 minutes using the existing local electric stove. By using the proposed electric stove to boil water, 113,793,148.104 KWh of energy per year at the national level can be saved

Respiratory health and acute pesticide intoxications among workers in the flower farm industry in Ethiopia

Background: The flower industry in Ethiopia is a rapidly growing economic activity involving tens of thousands of workers. On these farms, roses are cultivated inside greenhouses, which are characterized by elevated temperature, humidity, poor ventilation and frequent use of pesticides. Pesticides of different types are widely used by the flower industry in Ethiopia to enhance the growth of flowers. Workers in the flower industry are frequently exposed to organic dust from the flowers and the soil, including endotoxins, and to pesticides, which may result in adverse health effects. In addition, residents in the immediate area may risk increased exposure to pesticides through the proximity of their homes to the flower farms. Several studies have shown a high prevalence of respiratory symptoms and acute pesticide intoxications among agricultural workers. Few of these studies focus on greenhouse workers. Despite its great importance to the country’s economy, the working conditions and health status of the workers in the Ethiopian flower industry are not thoroughly documented. Objectives: The aims of this study were to describe working conditions on flower farms, to determine personal dust and endotoxin exposure levels, assess self-reported symptoms and acute pesticide intoxications (API), and to study respiratory inflammation by measuring exhaled nitric oxide among flower farm workers and residents living close to the farms. In addition, we aimed to determining work-related risk factors of API. Methods and materials: This project was conducted via three separate studies between 2012 and 2014 in selected Ethiopian flower farms and among the residents grouped according to their living proximity to one of the flower farms. In the first study, a work place survey was performed on three flower farms using a structured checklist. In addition, interviews were made, obtaining respiratory, neurological and dermal symptoms using the British Medical Research Council (BMRC) questionnaire, and a standardized questionnaire instrument of subjective health complaints among flower farm workers (n=213) and a control group of supermarket workers (n=60). In the second study, respiratory symptoms were assessed in an interview using the BMRC questionnaire among 248 female workers in four flower farms. The mean age, and years at work for the participants were 24 and 2 years, respectively. Measurements of exhaled nitric oxide were performed according to the American Thoracic Society and European Respiratory Society recommendations (n=108) using a portable electrochemistry-based sensor. Full-shift personal exposure to endotoxin was measured in samples of “total” dust in the environment, collected from the workers’ breathing zone (n=75). In the third study the prevalence of API was assessed among residents (n=516) living in the surrounding area of a large flower farm. Participants (mean age 30 years) were grouped according to their residence proximity to a large flower farm; living within 5 km, and 5–12 km away, respectively, from the flower farm. In structured interviews, we asked participants to report their exposure to pesticides and if they had experienced health symptoms within 48 hours of the exposure to the pesticides during the previous year. Those who had experienced this, and reported two or more typical pesticide intoxication symptoms at the time, were considered as having had API. In addition, risk factors of API were assessed among the residents who were either flower farm workers or small-scale farmers (n=440). Results: Workers at the flower farms generally had higher prevalence of respiratory, neurological and dermal symptoms than controls. Female workers inside the greenhouses had significantly higher prevalence of chronic respiratory and dermal symptoms than women working outside the greenhouses. Limited access to personal protective equipment (PPE) and unsafe pesticide routines were observed in all the flower farms examined. Greenhouse workers had higher endotoxin exposure than workers outside greenhouses, but the levels were relatively low, compared to European standards. The concentration of FeNO ranged from 5 to 166 ppb with a GM of 14 ppb. Only two workers had FeNO concentrations above 50 ppb, a level that often indicates the presence of asthma. FeNO was not different among those working inside and outside the greenhouses. The residents who live nearby and worked on the flower farm had significantly higher prevalence of API (56%) than did the residents living nearby but who did not work in the flower farm (16%). Flower farm workers had a higher risk of API than did small-scale farmers (PR=4.5, 95% CI: 3.20, 6.35). Lack of safety training, not following pesticide label instructions and not bathing after pesticides were used were significant risk factors for API among flower farm workers. Among small-scale farmers, none of the risk factors were significantly associated with API. Conclusion: The study revealed a high prevalence of self-reported respiratory, dermal and neurological symptoms and API among the workers on the flower farms. Lack of pesticide safety training, not following pesticide labels and poor personal hygiene measures were significant risk factors associated with API among flower farm workers. Dust or endotoxin levels were low and inflammation in the airways of the workers was not revealed when measured by exhaled NO