Full state observer-based pole placement controller for pulse width modulation switched mode voltage-controlled buck Converter.

Switched mode DC-DC converters play an important role in today's renewable energy systems, electric Vehicles, consumer electrical appliances, and many more. While many researchers have designed controllers for DC-DC converters, achieving low implementation cost remains a significant hurdle. This paper proposes a cost-effective observer-based pole placement controller for a PWM voltage-controlled Buck converter with clear step by step design approach. The state space averaged model of the DC-DC power converter is used to design pole placement with integrator compensator and full state observer. Pole placement is employed to improve the transient and steady state behavior of Voltage reference tracking response and full state observer is applied to extract the inductor current with the aim of removing the actual current sensor. Design specifications are set to a settling time of less than 5 msec and an overshoot of less than 5 %. While designing Observer-Controller combination, the separation principle, designing the controller and observer independently, is utilized by placing the observer poles far to the left of the controller poles for the Observer to converge faster. The designed controller and observer is verified with simulation in MATLAB/SIMULINK software and design of developed controller and observer are realized using low-cost analog electronics circuit components The results shows that the proposed system's strength in tracking the reference output voltage even in the presence of input voltage disturbance and the mean value of inductor current is well extracted having only the output voltage and MOSFET gate signal.

Effects of common interest groups on rural women and youth livelihood: A qualitative study from Central Ethiopia.

The study was conducted to examine the implications of the Common Interest Group (CIG) scheme for rural livelihood change in the selected areas of the Wara-Jarso woreda, Central Ethiopia. The study focuses on the activities of the CIGs, their effectiveness, Strengths, Weaknesses, Opportunities, and Threats, along with the changes in the livelihood status of CIG members. Four CIGs that fits into the aim of the study were purposively selected from the CIGs operating in the woreda. Among a qualitative research approach, a case study was employed. The data were collected from January 1, 2021 to February 28, 2021. Primary data were gathered using Focus Group Discussions and Key Informant Interviews. A thorough desk review of official documents and other secondary sources was made as an auxiliary method to capture sets of relevant information. The data organization was performed by the MAXQDA 2020 qualitative data analysis package program. The data were analyzed using thematic analysis, relational analysis, and content analysis methods. It was found that the CIGs have encouraged strong social capital among members and becomes an important alternative financial source. It was also found that the CIGs operation has encountered problems related to lack of entrepreneurial education and skill training, monitoring and evaluation, workplace, coordination among stakeholders, inadequate and improper financial use, and non-existence of market linkage. Their strengths, weaknesses, and opportunities were also indicated. For successful rural women and youth livelihood change through the CIGs scheme, the study recommends access to entrepreneurial skill training, coordination among relevant stakeholders, strong monitoring and evaluation, access to market linkage and workplace, and adequate funding.

Undernutrition and associated factors in orphan children aged 6-59 months in Gambella Southwest, Ethiopia: A community-based cross-sectional study.

OBJECTIVE: The study aimed to assess the prevalence of stunting, wasting, underweight and associated factors in orphaned children under 5 years old. DESIGN: A cross-sectional study. SETTING: Gambella City, Ethiopia. PARTICIPANTS: A sample of 419 under 5 orphaned children included in the study. Eligible households with orphans had selected using a systematic random sampling method. The lottery method was used when more than one eligible study participants live in the household. An OR with 95% CI was performed to measure the strength of association between each dependent variable and independent variables. Variables with p<0.05 were declared statistically significant. PRIMARY OUTCOME: The main outcome of this study was the prevalence of undernutrition among orphaned under 5 and its associated factors. RESULTS: Prevalence of stunting, wasting and underweight in orphan children under 5 were 12.2%, 37.8% and 21.7%, respectively. The prevalnce of wasting peaks among age group of 36-47 months (42.5%), whereas underweight peaks in 48-59 months (27.7%). Food insecurity, wealth index, family size, vitamin A supplementation, diarrhoea, fever 2 weeks before the survey, children under 5 and parents' death were associated with undernutrition. CONCLUSION: The prevalence of stunting, wasting and underweight among orphan children under 5 was significantly high. Multisectoral collaborative efforts towards access to health services, improving income-generating activities, micronutrient supplementation and social support and protection targeting orphan and vulnerable populations have to be built up.

Impact of urban expansion to peri-urban smallholder farmers' poverty in Tigray, North Ethiopia.

Urban expansion in African and other developing countries occurred and happening by encroaching fertile agricultural land. As a result, close to fifteen million people are displaced every year. This paper examines the consequences of urban expansion on peri-urban farmers' poverty. Data was generated from 341 (101 treated, 240 control) smallholder Peri-urban farmers'. Inferential statistics, propensity score matching (PSM), econometric models, and poverty measurements were applied and analyzed using Stata version 14 software. The impact assessment estimation showed the prevalence of poverty was higher by 5% poverty than non-displaced households. The intensity and incidence of poverty were also found higher among displaced households. Displaced and non-displaced households were deprived 49.4% and 46.5% of weighted indicators respectively, while the incidence of poverty was found 69% and 59% respectively. In sum, 34.1% of displaced and 27.4% of non-displaced households were poor. Besides the overall percentage of contribution of education, health, and living standard dimensions were 15.4%, 28.8%, and 55.8% among displaced households respectively. While percentage contribution of education, health, and living standard among non-displaced households were 15.1%, 26%, and 58.9% respectively. Therefore, the prevalence of poverty was higher in displaced households than in non-displaced households. The binary logistic regression also revealed out of the 13 covariates only four variables were found statistically significant. Of the four variables, except treatment effect or being displaced the rest variables family size, farming experience, and market distance were negatively affect household poverty. In conclusion, in all aspects, the result indicated that the prevalence of poverty was higher among evicted farmers. Therefore, government bodies should design strong strategies to avert the impact of urban expansion on peri-urban farmers. A separate department should be established which follow and provide training on time, and horizontal urban expansion should be changed to vertical expansion.

Assessment of the level and factors associated with knowledge, attitude and practice of blood donation among medical and paramedical personnel in ALERT Hospital, Ethiopia.

Background: Though there was a high blood supply need in response to high communicable disease and increased emergency conditions; the practice of health professionals and non-health professionals on voluntary blood donation is still unexpectedly low in Ethiopia. Health professionals and non-health professionals working in the health sectors are pivotal in taking the lead to reverse the effect of inadequate blood supply system in the country. Therefore, the study aimed to understand the level and contributing factors of knowledge, attitude and practice of voluntary blood donation among health and non-health professionals in ALERT Hospital, Addis Ababa, Ethiopia. Design and Methods: A cross-sectional study design was conducted among health professionals and non-health professionals in ALERT hospital from 5 to 30 June 2018. A total of 394 hospital staffs participated in this study. A well-structured self-administered questionnaire was used to assess the knowledge, attitude, and practice about voluntary blood donation. The statistical analysis was carried out using R. Results: A total of 203 (51.5%) participants were females. Only 142(36%) of the participants had voluntary blood donation practice. Among these, 60 (42.3%) of them were donated blood more than once. Occupation is the only factor significantly associated with blood donation practice; health professionals had almost two-fold donation practice than non-health professionals (AOR=1.62; 5% CI: 1.02, 2.57, p=0.042). Occupation has also a strong relationship with knowledge, health professionals had better knowledge than non-professionals with (AOR=2.39; 95% CI: 1.39, 4.12; p=0.002). The result also showed that the educational status of the participants was strongly associated with the blood donors' attitude with (AOR=3.62; 95%CI: 1.1, 11.93, p=0.035). One hundred and two (72.3%) of the blood donors were motivated to donate blood for charity, 133 (94.3%) individuals were felt good after blood donation and lack of request was the major reason 88.6% that causes the respondents not to donate blood frequently. Conclusions: Low blood donation practice of health professionals and non-health professionals was identified from this study. Occupation had significantly associated with blood donation practice. Therefore, targeted interventions aimed at mobilizing hospital staffs and develop accessible blood donation centers are recommended to reverse the effect of inadequate blood supply system in Ethiopia.