315 research outputs found
Determinants of Food Safety Practices Among Food Handlers in Selected Food Establishments
Despite great efforts against foodborne diseases, the occurrence of these problems remains a significant health issue in both developed and developing countries. This study was to assess determinants of food safety practice among food handlers in selected food establishments in Dire Dawa City administration, in 2017. Cross sectional survey was conducted among 356 food handlers from the selected food establishments in different categories. The CODEX food safety questionnaire was used to assess food safety knowledge (23 questions), attitude (six questions) and practice using interview and observation checklists (15 points). Satisfactory practice was defined as those who practice 70% of food safety measures correctly. Frequency, percentage, mean, binary logistic regression with a crude odds ratio and adjusted odds ratio (AOR) at 95% confidence interval were calculated. Out of the total study subjects, 354 food handlers participated in this study with 99.4% response rate. A total of 191 food handlers, 54.0% were female with overall mean age of 29.5 years. About 129 (36.4%), 194 (54.8%) and 106 (29.9%) had adequate knowledge, positive attitude and satisfactory food safety practice. Having food safety training (AOR= 2.0), with adequate knowledge (AOR = 2.83), positive attitude (AOR= 2.09), presence of food safety guideline (AOR = 2.23) and supervision (AOR= 2.07) were significant predictors of satisfactory food safety practices. In general food safety/hygienic practices of food handlers was found to be low. Having adequate knowledge, positive attitude, presence of food safety guideline and formal food safety training were significant predictors of food safety practices among food handlers
Numerical Investigation on Serpentine Flow Field and Rhombus Electrolyte Compartment of Vanadium Redox Flow Battery (V-RFB)
Selection of suitable material, fitting for prototype design and pumping rates are three affecting element for cost effectiveness and improve performance of vanadium cell prototype investigation. Therefore, three-dimensional numerical model isothermal computational fluid dynamics (CFD) model of vanadium redox flow battery (V-RFB) is studied. In this work, V-RFB with different electrolyte compartments is proposed and the effect of serpentine flow field is investigated. The performance of two V-RFBs with diamond and square electrolyte compartment is numerically tested. This work has been performed to optimize flow rate, electrolyte compartment design, avoid stagnant fluid and flow field application in VRFB. For the simulation, the flow was assumed to be incompressible, isothermal, steady state flow, laminar and Newtonian flow. Results show that the application of flow field and Rhombus type electrolyte compartment can facilitate the distribution of electrolyte in the unit cell uniformity and avoid stagnant in the tank. Simulation results indicate the diamond shape and serpentine flow field at optimal flow rate show the most suitable for V-RFBs than square shape
Effect of surface modification on mechanical properties of buri palm (corypha utan) fibre composite reinforcement
Natural fibre materials are replacing synthetic fibre materials since they are
considered as a low-cost, lightweight, and biodegradability engineering materials with a good
specific strength. However, the effects of some process and geometrical parameters (such as fibre
type, size, and concentration, and chemical modification) on the strength of the final natural
composite product are not well documented. The purpose of the research is to analyse the physical
and mechanical properties of single-strand buri palm fibre under different conditions and surface
modification. The buri palm fibre was treated using 5 wt.% and 10 wt.% sodium hydroxide (NaOH)
with a duration of 1 and 24 h immersion throughout the whole process. For a single-strand test, the
samples were carefully extracted from the corresponding woven fibre by hand. While the woven
buri palm fibre composite was fabricated by employing 4 and 5-layering sequences in the hand lay�up technique followed by the compression method. The buri palm fibre showed that a higher
concentration of NaOH solution and immersion period led to a lower density. The effectiveness of
the alkali treatment in the removal of cellulose and hemicellulose from the fibre strands was verified
by chemical composition in FTIR investigation. The highest tensile strength of 159.16 MPa was
indicated from the result of single-strand treated with 5 wt.% NaOH for 24 h immersion. This
treatment was found as the most appropriate treatment and is employed to fabricate both 4-layer
and 5-layer stacking sequence composite. The 5-layer treated composite gives the highest tensile
strength and flexural strength of 33.51 MPa and 56.72 MPa, respectively. In conclusion, the
mechanical properties increased with the addition of each sequence layering treated fibres in the
composite. The obtained results indicate that the utilisation of buri palm fibre as a reinforcement in
the epoxy composite can be used in the lightweight and moderate load applications, such as the
interior parts in the automotive industry
The effect of fibre treatment on water absorption and mechanical properties of buri palm (Corypha utan) fibre reinforced epoxy composites
Over the past century, there has been a dramatic increase in natural fibre
composites in which natural fibre has served as reinforcement in polymer. However, the existence
of moisture and defects in natural fibres has impacted the mechanical and physical properties of
natural fibre polymer composites. The main objective of this study is to fabricate the buri palm fibre
reinforced epoxy composite and evaluate the effects of fibre treatment on water absorption and
tensile properties. The buri palm fibre were treated by using 5 wt.% NaOH for 24 h and the
laminated composite of untreated and treated four-layer and five layer fibres were fabricated via
hand lay-up process. The tensile specimens are prepared according to the ASTM D638 standard
and the water absorption experiment was conducted by immersing the specimen in distilled water
at room temperature until it reached the saturated moisture absorption. The results revealed that
the percentage of moisture uptake was reduced to 69% and 95% in treated four-layer and five�layer sequences. It is observed that the thickness swelling of the composite increased with the
increase of sequence layering, while the thickness swelling decreased with treated fibre. Alkali
treatment affected the properties of buri palm fibre which improved the interfacial bonding between
the fibre and epoxy matrix for better tensile properties and reduced water absorption. Finally,
morphology examinations were carried out to analyse the fracture behaviour and fibre failure on
the tensile test specimen by using microscope analysis
Update on COVID-19 Pandemic
Objective: This update is concerned on the coronavirus disease (COVID-19) pandemic that is affecting the globe. The aim of this update is to summarize the up-to-date knowledge about the virus, its way of transmission, clinical features, diagnosis, and treatment.
Result: The COVID-19 is a public health threat affecting humankind currently after the emergence and spread of the novel coronavirus or the severe acute respiratory syndrome coronavirus 2. The virus is believed to have originated from bats and transmitted to humans. Around 1.5 million peoples are confirmed to have the COVID-19 and more than 83000 individuals have died of it by April 8, 2020, all over the world. It is transmitted by inhaling or having contact with droplets. The incubation period ranges from 2-14 days. It manifests mainly with fever, non-productive cough, and dyspnea. The polymerase chain reaction from various samples like throat swabs, nasal swabs, bronchoalveolar lavage fluid is used to confirm the diagnosis. High-resolution chest computerized tomography is abnormal in most patients, and typical findings are ground glass patchy opacities on both lungs and sub-segmental consolidation. Treatment is largely supportive. However, trials are ongoing, and chloroquine and hydroxychloroquine have got a lot of attention in the battle against COVID-19
Tensile Properties of Glass Fiber Reinforced Polyamide 6-Polypropylene Composites
In this research study, glass fiber (GF) reinforced polyamide 6 (PA6)-polypropylene blends were prepared using injection molding machine. Test specimens of five different compositions such as, 70%PA6+30%PP, 65%PA6+30%PP+5%GF, 60%PA6+30%PP+10%GF, 55%PA6+30%PP+15%GF and 50%PA6+30%PP+20%GF were prepared successfully. The effects of glass fiber content on the tensile properties of the composites were investigated. Test results reveal that yield strength, elastic modulus, tensile strength and tensile elongation are influenced by glass fiber content. Results show that yield strength is low for 70%PA6+30%PP pure polymer blend whereas 50%PA6+30%PP+20%GF composite shows high yield strength. Test results also show that elastic modulus is low for 70%PA6+30%PP, it increases with the increase in fiber content and elastic modulus is remarkably high for 50%PA6+30%PP+20%GF composite. On the other hand, tensile strength is low for 70%PA6+30%PP blend and tensile strength of GF reinforced composite increases steadily with the increase in glass fiber content. In addition, the tensile elongation of 70%PA6+30%PP pure blend is very high, whereas the composite shows reduced tensile elongation with the increase in fiber content and particularly, 50%PA6+30%PP+20%GF composite shows notably low tensile elongation
Household crowding, social mixing patterns and respiratory symptoms in seven countries of the African meningitis belt.
OBJECTIVES: To describe the variation in household crowding and social mixing patterns in the African meningitis belt and to assess any association with self-reported recent respiratory symptoms. METHODS: In 2010, the African Meningococcal Carriage Consortium (MenAfriCar) conducted cross-sectional surveys in urban and rural areas of seven countries. The number of household members, rooms per household, attendance at social gatherings and meeting places were recorded. Associations with self-reported recent respiratory symptoms were analysed by univariate and multivariate regression models. RESULTS: The geometric mean people per room ranged from 1.9 to 2.8 between Ghana and Ethiopia respectively. Attendance at different types of social gatherings was variable by country, ranging from 0.5 to 1.5 per week. Those who attended 3 or more different types of social gatherings a week (frequent mixers) were more likely to be older, male (OR 1.27, p<0.001) and live in urban areas (OR 1.45, p<0.001). Frequent mixing and young age, but not increased household crowding, were associated with higher odds of self-reported respiratory symptoms (aOR 2.2, p<0.001 and OR 2.8, p<0.001 respectively). A limitation is that we did not measure school and workplace attendance. CONCLUSION: There are substantial variations in household crowding and social mixing patterns across the African meningitis belt. This study finds a clear association between age, increased social mixing and respiratory symptoms. It lays the foundation for designing and implementing more detailed studies of social contact patterns in this region
Characterization of the indigenous goat production system in Asossa zone, Benishangul Gumuz region, Ethiopia
Most of the livestock population in Asossa zone is comprised of indigenous goats, which have remarkable socioeconomic relevance to the society. This study aimed to generate information on the production system and production constraints of goats in the study area. The study was conducted based on a household survey in which 192 householdswere purposively sampled. The households were located in Sherkole, Kurmuk and Menge districts that have a high goat population in Asossa zone. Data were recorded inMS Excel data sheet and analyzed using SAS. A chi-square and GLM procedure of SAS was used to test significant differences among categorical and quantitative variables. The primary reason for keeping goats was for cash income with an index value of 0.46, 0.34 and 0.31 for Sherkole Kurmuk and Menge districts, respectively. Milk was the second purpose for rearing goats, with a ranking index value of 0.29, 0.30 and 0.30 for Sherkole, Kurmuk, and Menge districts, respectively. Grazing on natural pasture was the major feed source for goat production in the three districts (with an index of 0.86, 0.91 and 0.0.87 for Sherkole, Kurmuk and Menge districts, respectively). Although the majority of households (59 %, 75% and 62.5% in Sherkole, Kurmuk, and Menge districts, respectively) used yard type of housing, the number of households that used this type of housing was significantly different (p<0.05) among the three districts. Majority of goat owners used an uncontrolled type of mating that accounts 92.2%, 89.1% and 85.9% in Sherkole, Kurmuk, and Menge districts, respectively. Feed shortage (with ranking index value of 0.30, 0.34 and 0.28 in Sherkole Kurmuk and Menge districts, respectively) and water shortage (with ranking index value 0.21, 0.23 and 0.22 in Sherkole Kurmuk and Menge districts, respectively) were the first and second goat production constraints. Age at sexual maturity was 7.52 months for males and 7.84 months for female goats in this region. Goats play a multi-functional role for the community by adapting to the different constraints that need intervention mechanisms from responsible bodies to boost the productivity of the sector.Key words: constraints, Ethiopia, feed, housing, indigenous goats, reproductive performance, production system, wate
A Low-Cost Digital Torquemeter Coordinated by Arduino Board
Lab based experimental procedure requires standardized instrument for data acquisition and analysis in which is costly. However, self-made and well calibrated instrument is cost effective in contrast to industrial grade scientific instrument. Therefore, a low-cost torquemeter system is developed to investigate the torque generated by wind turbine system. The presented torquemeter system comprises of two subsystems namely photointerrupter (primary) and load cell (secondary). The reliability of the developed system is analyzed by stages in order to verify the effectiveness in acquiring measurement namely RPM, weight (load) and torque. It is found that 5 kg load cell illustrated unsteady noise behavior relative to the defined calibration weight. Meanwhile, the percentage of accuracy (Pa) of final 3th reading is Pa = 94.709 %, 97.32 %, 98.826 % for 10 g, 20 g and 100 g respectively. Measurement acquired from torquemeter system is compared against 2D CFD numerical model under similar flow condition. Results shows that the measurement of torquemeter system is Mt = 0.731842 and as for CFD model is Mt = 0.82553 which results in error (%) of Pe = 11.35 %. However, the CFD numerical model has overpredicted moment value since it has compensated the blockage factor and external environmental factors. It is safe to say, that the presented instrument is applicable and feasible for WT torque acquisition
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