Understanding the Strain Localization and Progressive Damage Growth at the Free-Edge of Composite Laminates Using Digital Image Correlation

Understanding the mechanics of Fiber Reinforced Composites (FRC) that guide the design and optimization of laminate structures, have attracted numerous researchers. For the last five decades, various analytical and numerical models have been developed to understand the damage and failure mechanisms in FRC. For long, Classical laminate plate theory (CLPT) has majorly been used as a theoretical guide in the design of composite structures. The CLPT framework is developed based on the consideration of an infinitesimal wide plate that depicts a planar stress condition. Thus, as it considers only the planar stresses, the out of plane interlaminar stresses are absent from the CLPT formulation. However, for a laminate with finite width or geometrical discontinuity a complex stress condition (which includes interlaminar stresses) is expected on the free surface of the discontinuities. In such, researcher has developed models that considered a three-dimensional stress condition, and these models have revealed the great relevance of understanding the stress condition at the free-edge on the design and failure prediction of composite structures. Nevertheless, there is still a need for further experimental investigations on the free-edge stress/strains localization and their association with the damage initiated at the free-edge. In this study a noble experimental technique is developed and applied to study the strain localization at free-edge of composite laminate under a monotonic tensile load. The technique is used to evaluate the local strain variation across the layers of the laminate free-edge along with the applied uni-axial tensile load. The developed experimental technique has incorporated high magnification optical system for digital image correlation (DIC) in which the full field displacement and strain are measured in-situ at micro-scale. Further, based on the DIC results, the initiation and growth of cracks from the free-edge can be captured, thus, the influence of the strain localization on the formation of damage can be investigated. In overall, this dissertation is grouped in to four categories to address the various issues raised regarding free-edge effect. In the first section, a single a quasi-isotropic (±45/ 90/ 0)s laminate is considered and the strain localization and progressive damage formation at the free-edge of the laminate is investigate. In the second part, four different laminates with varying laminas stacking arrangement are fabricated, and the influence of the relative location of laminas on the interlaminar strain localization and damage formation is studied. In the third part, by taking one stacking arrangement with different fiber angle of the off-axis plies, the effect of ply’s orientation on the local intra-lamina and interlaminar strain localization and damage formation is studied. In the last section, investigation is conducted to understand the explicit correlation between local damage, material residual stiffness degradation and loss in thermal conductivity of carbon fiber composite

Analysis of technical efficiency of rice production in fogera district of Ethiopia: A stochastic frontier approach

The possible way to improve production and productivity with a given input mix and available technology is to improve efficiency of resource use. For this purpose examining the technical efficiency of the production process is very crucial. Thus, the aim of this paper is to analyze the technical efficiency of rice production in Fogera District of Ethiopia. To do so, stochastic frontier approach is employed on a data which is collected from 200 sample households in 2015/16 production year. The sampling techniques used to get those 200 sample households is a multistage sampling where in the first stage five Kebeles were purposively selected, in the second stage two Gotes randomly selected from each Kebeles and in the third stage 200 households were selected using simple random sampling technique. Doing so, it was found that except manure all the variables in the Cobb-Douglass stochastic frontier model which includes; land, fertilizer, oxen, seed and labor are found to be positively and significantly related to rice production. The average technical efficiency score predicted from the estimated Cobb-Douglas stochastic frontier production function is found to be 77.2% implying that there is a room for rice yield increment by improving the resource use efficiency of the households. The study also revealed that; provision of extension service, training on rice product improvement, experience on rice farming; agrochemical and education tend to be positively and significantly related to technical efficiency while household size is negatively and significantly related. Thus, strengthening extension service provision and training on rice yield increment, campaigns to disseminate rice farming experiences and increasing the supply of agrochemicals are crucial to improve the technical efficiency of rice production in the study area

Analysis of the technical efficiency of rice production in Fogera district of Ethiopia: a stochastic frontier approach

The aim of this paper is to analyze the technical efficiency of rice production in Fogera District of Ethiopia. To do so, the stochastic frontier approach was employed on a data collected from 200 sample households in the 2015/16 production year. As a result, it was found out that except for manure, all variables in the Cobb-Douglass stochastic frontier model, which includes land, fertilizer, oxen, seed, and labor, were positively and significantly related to rice production. The average technical efficiency score predicted from the estimated Cobb-Douglas stochastic frontier production function was calculated to be 77.2 percent, implying that there was a room for rice yield increment by improving the resource use efficiency of households. The study also revealed that the provision of extension services, training on rice product improvement, experience on rice farming, agrochemicals, and education tend to be positively and significantly related to technical efficiency while household size was negatively and significantly related. Thus, strengthening the extension service provision and the training on rice yield increment, campaigns to disseminate rice farming experiences, and an increase in the supply of agrochemicals were crucial to improve the technical efficiency of rice production in the study area.Keywords: Ethiopia, Fogera District, Technical Efficiency, Cobb-Douglas Production Function, Stochastic Frontier ApproachJEL classification: D2

Public-private collaboration in the Tourism Industry in Northwestern Ethiopia.

Tourism has become an important socio-economic development tool in many parts of the world, including developing countries such as Ethiopia. To sustainably develop the existing and potential destinations, collaboration among key stakeholders is of high importance. Amongst these key actors, the private and public sectors are the leading ones. This study was conducted at the two World Heritage Sites of Ethiopia: Gondar and Lalibela, and the UNESCO registered Biosphere Reserve of Lake Tana, including the UNESCO Learning city of Bahir Dar. These destinations are strategically located in Northwestern Ethiopia, in the Northern historic route of the country which receives the largest number of international visitors of the country. The study area is famous for unique cultural, historical, religious, religious and natural attractions. The necessary data for this study were mainly collected using a semi-structured in-depth interview methodology. The researchers used a purposive sampling technique and the total samples selected were 35, which was based on theoretical saturation. It was found that the public and private sectors in the tourism industry in the three destinations, were not working together to the level expected. They were working only in limited areas, and hotels were found to be better participants in the collaboration process. The major challenges for the feeble collaboration are associated with the government’s limitations in commitment, financial and manpower capacity. For better public-private collaboration, the government should take the leading role and create a conducive environment for collaboration with the private sector, so that tourism can be developed in a way that benefits visitors, businesses and the destinations and remains sustainable

The Scenic Beauty of Geosites and Its Relation to Their Scientific Value and Geoscience Knowledge of Tourists: A Case Study from Southeastern Spain

Scenic beauty is one of the most-commonly used indicators in the inventory and assessment of geosites for geoconservation, geoheritage management and geotourism development. It is an important driver of tourists to visit natural areas and it also provides support for the protection of natural heritage. Previous studies on scenic beauty mainly focused on landscape preference and physical characteristics of geosites that affect scenic beauty appreciation. The relationships between the scenic beauty of geosites, their scientific value and the geoscience knowledge of tourists has not been empirically investigated in detail. Hence, this study investigates this relationship using 34 geosites from southeastern Spain. For this purpose, 29 respondents with a geoscience background and who all visited the 34 geosites, 43 respondents with a geoscience background but who did not visit the geosites, and 104 respondents with no geoscience background and who did not visit the geosites, participated in a survey. The first group rated the scenic beauty and the scientific value of the geosites based on a direct field visit during which the scientific background of these geosites was given. On the other hand, the latter two groups rated scenic beauty using representative photos of the geosites. A five-point Likert scale was used to rate the scenic beauty and the scientific value of the geosites. We found a significant relationship between the scenic beauty of geosites and their scientific value, and this relationship becomes more significant if the geoscientific knowledge of the respondents increases. One-way ANOVA results indicated that a geoscience background contributed to higher perceived scenic beauty, especially for those geosites that in general were considered as more scenic by all the respondent groups. It was also found that geosites with viewpoints received in general higher scenic beauty and scientific value ratings

Analysis of technical efficiency of rice production in fogera district of Ethiopia: A stochastic frontier approach

The possible way to improve production and productivity with a given input mix and available technology is to improve efficiency of resource use. For this purpose examining the technical efficiency of the production process is very crucial. Thus, the aim of this paper is to analyze the technical efficiency of rice production in Fogera District of Ethiopia. To do so, stochastic frontier approach is employed on a data which is collected from 200 sample households in 2015/16 production year. The sampling techniques used to get those 200 sample households is a multistage sampling where in the first stage five Kebeles were purposively selected, in the second stage two Gotes randomly selected from each Kebeles and in the third stage 200 households were selected using simple random sampling technique. Doing so, it was found that except manure all the variables in the Cobb-Douglass stochastic frontier model which includes; land, fertilizer, oxen, seed and labor are found to be positively and significantly related to rice production. The average technical efficiency score predicted from the estimated Cobb-Douglas stochastic frontier production function is found to be 77.2% implying that there is a room for rice yield increment by improving the resource use efficiency of the households. The study also revealed that; provision of extension service, training on rice product improvement, experience on rice farming; agrochemical and education tend to be positively and significantly related to technical efficiency while household size is negatively and significantly related. Thus, strengthening extension service provision and training on rice yield increment, campaigns to disseminate rice farming experiences and increasing the supply of agrochemicals are crucial to improve the technical efficiency of rice production in the study area

Analysis of technical efficiency of rice production in fogera district of Ethiopia: A stochastic frontier approach

The possible way to improve production and productivity with a given input mix and available technology is to improve efficiency of resource use. For this purpose examining the technical efficiency of the production process is very crucial. Thus, the aim of this paper is to analyze the technical efficiency of rice production in Fogera District of Ethiopia. To do so, stochastic frontier approach is employed on a data which is collected from 200 sample households in 2015/16 production year. The sampling techniques used to get those 200 sample households is a multistage sampling where in the first stage five Kebeles were purposively selected, in the second stage two Gotes randomly selected from each Kebeles and in the third stage 200 households were selected using simple random sampling technique. Doing so, it was found that except manure all the variables in the Cobb-Douglass stochastic frontier model which includes; land, fertilizer, oxen, seed and labor are found to be positively and significantly related to rice production. The average technical efficiency score predicted from the estimated Cobb-Douglas stochastic frontier production function is found to be 77.2% implying that there is a room for rice yield increment by improving the resource use efficiency of the households. The study also revealed that; provision of extension service, training on rice product improvement, experience on rice farming; agrochemical and education tend to be positively and significantly related to technical efficiency while household size is negatively and significantly related. Thus, strengthening extension service provision and training on rice yield increment, campaigns to disseminate rice farming experiences and increasing the supply of agrochemicals are crucial to improve the technical efficiency of rice production in the study area

Knowledge of Pregnant Women on Mother-to-Child Transmission of HIV in Meket District, Northeast Ethiopia

Knowledge of pregnant women on the three periods of mother-to-child transmission (MTCT) of HIV has implication for child HIV acquisition. This study aims to assess the knowledge of pregnant women on mother-to-child transmission of HIV and to identify associated factors in Meket district, northeast Ethiopia. Logistic regression models were fitted to identify associated factors. Adjusted odds ratios (AOR) with 95% confidence intervals (CI) were used to determine the presence and strength of association. About onefifth (19%) of women were knowledgeable on mother-to-child transmission of HIV (95% CI: 15.5%, 22.4%). Being urban resident (AOR: 2.69, 95% CI: 1.48, 4.87), having primary education (AOR: 2.41, 95% CI: 1.03, 5.60), reporting receiving information on HIV from health care providers (AOR: 3.24, 95% CI: 1.53, 6.83), having discussion with partner about mother-to-child transmission of HIV (AOR: 2.64, 95% CI: 1.59, 4.39), and attending antenatal care (AOR: 5.80, 95% CI: 2.63, 12.77) were positively associated with increased maternal knowledge of mother-to-child transmission of HIV. Knowledge of mother-to-child transmission of HIV among pregnant women was low. Providing information, especially for rural women and their partners, is highly recommended. Background Vertical transmission of Human Immunodeficiency Virus (HIV) is still a major challenge in the world, especially in developing countries Without any intervention, the risk of a baby getting HIV infection from an infected mother ranges from 15% to 25% in the developed nations and from 25% to 35% in developing countries. HIV transmission rate and timing are estimated to be 5% to 10% during pregnancy, 10% to 15% during delivery and 5% to 20% through breast-feeding. In general mother to child transmission contributes 15-45% of HIV acquisition for children The national adult HIV prevalence in Ethiopia is 1.2% It is estimated that 138, 906 children less than 15 years are living with HIV in 2014. There are an estimated 3,886 new infections each year due to mother-to-child transmission According to Ethiopian Demographic and Health Survey (EDHS) report, about three-quarters of reproductive aged women know that HIV can be transmitted to a baby through breastfeeding Maternal knowledge on MTCT is a corner stone of effective implementation of the World Health Organization (WHO) recommendation of the four-pronged approach to reduce mother-to-child transmission of HIV Despite the large challenge of vertical transmission of HIV, there were also limited community-based studies on women knowledge on mother-to-child transmission of HIV. Hence, this study attempts to fill the gap through assessing the level of knowledge of MTCT of HIV and its associated factors at Meket district, Northeast Ethiopia. Methods Study Design, Population, and Setting. A communitybased cross-sectional study design was conducted in Meket district, northeast Ethiopia, from March 8 to 21, 2014. Meket district is located 665 km north of Addis Ababa, the Ethiopian capital city. The district has an estimated population size of 254,520 of which 59,939 are reproductive aged women, and an estimated 8,246 were pregnant women. Those pregnant women are living in Meket district were constituted our study population. Sample Size and Sampling Procedure. Sample size was determined using single population proportion formula with the assumptions of 95% level of confidence, 12% proportion of knowledgeable women on MTCT of HIV Operational Definitions. In the present study, pregnant woman was regarded as being knowledgeable on MTCT if she correctly identified the three different modes/periods of MTCT of HIV; otherwise she was classified as nonknowledgeable. Comprehensive knowledge of HIV was also measured if a pregnant woman correctly identified three modes of transmission of HIV (unsafe sexual practice, blood transfusion, and MTCT) and recognized two common misconceptions. Comprehensive knowledge about HIV/AIDS was measured after posing the following questions: (1) knowing that condom use and limiting sex partners to one uninfected partner are HIV prevention methods, (2) being aware that a healthy-looking person can have HIV, and (3) rejecting the two most common local misconceptions, that is, HIV/AIDS can be transmitted through mosquito bites and by supernatural means in Ethiopia Data Collection Procedures. Data were collected using pretested, structured, and interviewer administered questionnaire. The questionnaire was prepared after reviewing relevant literatures. Five female nurses supervised by two BSc health professionals collected the data. For eligible women who were not at home during our first attempt, the interviewers revisited the participant's home at least two times before excluding the participant. Training was given to the data collectors about informed consent, techniques of interviewing, data collection procedures, and different sections of the questionnaire. Supervisors and principal investigators checked the questionnaire on its completeness and consistency on the daily basis. Data Processing and Analysis. The data were entered into EPI info version 3.5.3 statistical software and then sorted, cleaned, and analyzed by using SPSS version 20 statistical package. Descriptive statistics were done to describe the study participants in relation to relevant variables. Both bivariate and multiple logistic regression analyses were carried out to see the effect of sociodemographic factors, maternal condition factors, and other factors on the knowledge of MTCT of HIV and to control cofounding. Odds ratios with 95% CI were computed to identify factors associated with mothers' MTCT knowledge. Ethical Consideration. Ethical clearance was obtained from the Research and Ethical Review Committee (REC) at the Institute of Public Health, College of Medicine and Health Science of University of Gondar. Permission letter was secured from Meket District Health Office. Written informed consent was taken from each study participant after reading the consent form. The purpose and benefit of the study and their right to withdraw at any time were also delivered to each participant prior to the interview. Confidentiality of the information was maintained throughout by using anonymity identifiers, keeping their privacy by interviewing them individually. Results Sociodemographic Characteristics of Pregnant Women. Five hundred forty-two pregnant women participated in the study (97.5% response rate). The majority (85.4%) were rural dwellers. The mean age of the study participants was 29.45 years (SD = 5.4). Four hundred and sixty (84.9%) were married, 196 (36.2%) were able to read and write, and nearly four-fifths (80.1%) were homemaker ( Journal of Pregnancy 3 Knowledge of Pregnant Women on MTCT. One hundred three (19%) (95% CI: 15.5%, 22.4%) were knowledgeable on MTCT of HIV. Most (84.5%) heard about mother to child transmission of HIV. Among those who heard MTCT, more than two-thirds (70.7%) mentioned labor/delivery as a time of HIV transition from mother to child. 225 (41.5%) pregnant women identified at least two periods of motherto-child transmission of HIV. Nearly two-thirds (63.8%) had comprehensive knowledge on HIV/AIDS, and another equivalent proportion of women heard about PITC Factors Associated with Knowledge of Pregnant Women on MTCT of HIV. In multivariable analysis, higher levels of maternal education status, having received information about HIV from health professionals, and reported discussion of MTCT and ANC with their partners were positively associated with knowledge of mother-to-child transmission of HIV. Those women who live in the urban settings were about three more like to be knowledgeable than their rural counterparts (AOR: 2.69, CI (1.48, 4.87)). Those literate mothers were about three times more likely to be knowledgeable than who did not read and write (AOR: 3.25, CI (1.55, 6.78)). Likewise, a woman was 2.41 times more likely to be knowledgeable if she had completed primary school as compared to those who did not read and write (AOR: 2.41, CI (1.04, 5.60)). Pregnant women who received information on HIV from health care providers were about three times more likely to be knowledgeable than women who had not received information (AOR: 3.24, CI (1.54, 6.83)). Women who had discussions with their partner were more likely to be knowledgeable than those who had not (AOR: 5.80, CI (2.63, 12.78)). Correspondingly, mothers who discussed MTCT with their partners were more likely to be knowledgeable than those who had not (AOR: 2.64, CI (1.59, 4.39)) Discussion Being knowledgeable on MTCT of HIV and the fact that the risk of transmission can be reduced by using antiretroviral drugs are critical in reducing MTCT of HIV. This can contribute greatly towards the achievement of the Millennium Development Goals related to HIV. This study revealed that 19% (95% CI: 15.5%, 22.4%) of respondents were knowledgeable on MTCT of HIV. This result is in line with a cross-sectional study conducted at Temeke District Hospital, Dar Es Salaam (15.7%) In the present study, nearly two-thirds of pregnant women had comprehensive knowledge on HIV/AIDS which is higher than studies in Yaoundé (23%) Knowledge of pregnant women on MTCT of HIV among pregnant women was significantly varied based on their place of residence. Those pregnant women residing in urban areas were more likely to be knowledgeable when compared to the rural residents. This finding is in line with studies conducted at Gondar and Hawassa towns in Ethiopia In this study, pregnant women who discussed and received information about HIV/AIDS from health care providers were more knowledgeable. They were found to be three times more likely to be knowledgeable than those who had not. Spouse discussion on antenatal care follow-up was also positively associated with knowledge of MTCT. Those pregnant women who had discussions with their partners were six times more likely to be knowledgeable than those who had not discussed the issue. This is similar to reports from other studies Pregnant women may receive information from a variety of sources about health services. Spouses having delivered information and participated in discussions about MTCT of HIV with their wives (40.6%) were associated with good knowledge of the subject. Accordingly, pregnant women who had discussion with their partners were more than two times more likely to have good knowledge of MTCT. This might be because partner discussion in this regard could enhance their knowledge. This study tried to assess pregnant women who did not attend health care facilities for ANC and HIV concerning their knowledge about MTCT of HIV. However, because of financial and time constraints, this study did not include the knowledge part of prevention of mother-to-child transmission of HIV. Conclusions Despite many efforts, the knowledge of pregnant women on mother-to-child transmission of HIV is low. If pregnant woman resides in urban environment, she attends school, if she receives information on HIV from health care providers, and if she attends antenatal care, she is more likely to be knowledgeable on MTCT of HIV. Strengthening women education and by reaching previously inaccessible parts of the community, integration of HIV, prevention of MTCT, and ANC service, is highly recommended. Moreover, strengthening discussion of MTCT with spouses is important

Country contextualisation of cost-effectiveness studies: lessons from Ethiopia

Emerging demographic, epidemiological and health system changes in low-income countries require revisions of national essential health services packages in accordance with standard healthcare priority setting methods. Policy makers are in need of explicit and user-friendly methods to compare impact of multiple interventions. We provide experiences of country contextualisation of WHO-CHOICE methods and models to a country level. Results from three contextualised cost-effectiveness analyses (CEAs) are presented, and we discuss how this evidence can inform priority setting in Ethiopia. Existing models for a range of interventions in obstetric and neonatal care, psychiatric and neurological treatment and prevention and treatment of cardiovascular diseases are contextualised to the Ethiopian setting. CEAs are defined as contextualised if they include national analysts and use country-specific input for either costs, epidemiology, demography, baseline coverage or effects. Interventions (n=61) are ranked according to incremental cost-effectiveness rates (ICERs), and expected health outcomes (Disability Adjusted Life Years (DALYs) averted) and budget impacts are presented for each intervention. Dominated interventions (n=30) were excluded. A USD2.8 increase per capita in the annual health budget is needed in Ethiopia (currently at USD28 per capita) for increasing coverage by 20%–75% for all the 22 interventions with positive net health benefits. This investment is expected to give a net benefit at around 0.5 million DALYs averted in return in total, with a willingness to pay threshold at USD2000 per DALY averted. In particular, three interventions, neonatal resuscitation, kangaroo mother care and antibiotics for newborn sepsis, stand out as best buys in an Ethiopian setting. Our method of contextualised CEAs provides important information for policy makers. Rank ordering of interventions by ICERs, together with presentations of expected budget impact and net health benefits, is a clear and policy friendly illustration of possible efficient stepwise pathways towards universal health coverage.publishedVersio

Ethnobotanical study of medicinal plants used by people in Zegie Peninsula, Northwestern Ethiopia

An ethnobotanical study was conducted from October 2005 to June 2006 to investigate the uses of medicinal plants by people in Zegie Peninsula, northwestern Ethiopia. Information was gathered from 200 people: 70 female and 130 males, using semistructured questionnaire. Of which, six were male local healers. The informants, except the healers, were selected randomly and no appointment was made prior to the visits. Informant consensus factor (ICF) for category of aliments and the fidelity level (FL) of the medicinal plants were determined. Sixty-seven medicinal plants used as a cure for 52 aliments were documented. They are distributed across 42 families and 64 genera. The most frequently utilized plant part was the underground part (root/rhizome/bulb) (42%). The largest number of remedies was used to treat gastrointestinal disorder and parasites infections (22.8%) followed by external injuries and parasites infections (22.1%). The administration routes are oral (51.4%), external (38.6%), nasal (7.9%), and ear (2.1%). The medicinal plants that were presumed to be effective in treating a certain category of disease, such as 'mich' and febrile diseases (0.80) had higher ICF values. This probably indicates a high incidence of these types of diseases in the region, possibly due to the poor socio-economic and sanitary conditions of this people. The medicinal plants that are widely used by the local people or used as a remedy for a specific aliment have higher FL values (Carissa spinarum, Clausena anisata, Acokanthera schimperi, Calpurnia aurea, Ficus thonningii, and Cyphostemma junceum) than those that are less popular or used to treat more than one type of aliments (Plumbago zeylanicum, Dorstenia barnimiana)