28 research outputs found

    The enslaved family as reflected in Post-colonial African Drama: Ngugi and Ngugi’s I Will Marry When I Want

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    In literary studies, critics demonstrate authors’ role to depict human life using characters and themes affecting them through various literary forms viz prose fiction, poetry and drama. The latter tells a story by engaging dialogue and conflicts among characters. Driven by the didactic literary theory, the researchers carry out a literary analysis of Ngugi wa Thiong’o and Ngugi wa Mirii’s morality play “I Will Marry When I Want”; and explore the situation of an enslaved family reflected in the impossible promise of the land grabber and exploiter targeting a one and half acres of land that the family was living on. Discussion centers on character victims in the story, leading to the conclusion that the play depicts the hypocrisy and power of the elite - haves at the expense of the poor in post-colonial Africa. The Kioi’s malice unbeknown to Kiguunda’s family is one of many cases of human bad manners that affect society members due to their poor life background rooted in the effects of exploitation and oppression; resulting in the victim’s wrong choice motivated by the stopgap altogether

    New Mixture Additives for Sustainable Bituminous Pavements

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    In an effort to improve mechanical properties of asphalt concrete, an exploratory research using mixture additives was attempted. Two different types of additives on two material scales were used: asphalt concrete (AC) level and binder level. At the start of this study, the effect of natural cornhusk fibers on the resistance of two types of AC mixtures on cracking were tested for hot-mix asphalt (HMA) and cold-mix asphalt (CMA). The results showed slight improvements in cracking resistance in cornhusk reinforced HMA, and in the case of the CMA, marshal flow. Overall, based on the test results, cornhusk-reinforced HMA and CMA may not significantly improve critical mechanical properties given the added cost of fibers. In addition, cornhusk fibers proved difficult to properly disperse in HMA and CMA when mixed in laboratory. However, when fibers were mixed in an asphalt production plant, the fibers appeared to become more distributed. The second part of this study, two different types of carbon nano-fillers (F1 and F2) with different surface properties and sizes were added to two different asphalt binders: the base binder and the polymer modified binder. Also, mastic samples were prepared by replacing parts of the limestone filler by the carbon nano-fillers. It was observed that the nanoscale additives interacted with the binder quite differently. Additive F1 did not show a drastic improvement in the mechanical properties, fatigue resistance, and rutting resistance of the base and polymer modified binder at the mastic and the binder scale; however, additive F2 improved all the above- mentioned properties. From the experimental investigation, it can be inferred that part of the polymer modification can be replaced by additive F2. Although additive F1 showed a minimal change, it could be useful in improving the secondary application of the pavement, such as the electrical conductivity, thermal conductivity, and absorption of radiation for energy storage, which was not the scope of this study but appears worthy to investigate

    Assessing Impact and Blast Resilience of Polymer Coated Cementitious Materials

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    RESEARCH MOTIVATION: The bridge piers are highly vulnerable to the impact and blast loads. The position in which they are constructed makes it difficult to install protective devices around them. By the current AASHTO standard, it is possible to under-design bridge piers for commercial vehicle impacts and other events such as blast. OBJECTIVE: To improve impact and blast resilience of bridge piers using polymeric coatings. CONCLUSION ‱ Polymer coating of Portland cement concrete can be achieved with a good bonding. ‱ The polymeric coating seem to improve impact resilience of Portland cement concrete by increasing absorbed impact energy (i.e., area underneath the curve of acceleration vs time)

    Development of a Semicircular Bend (SCB) Test Method for Performance Testing of Nebraska Asphalt Mixtures

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    Research on High-RAP Asphalt Mixtures with Rejuvenators - Phase II

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    A previous study by the authors have demonstrated effectiveness of three rejuvenators: R1 (triglyceride/fatty acid: agriculture-tech based), R2 (aromatic extract: petroleum-tech based), and R3 (tall oil: green-tech based) on rejuvenating properties of the aged binder. In that study, it was observed that the rejuvenators made high-RAP mixtures softer and more compliant, which may increase the rutting potential, while they simultaneously improve cracking resistance of the high-RAP materials. Research outcomes and findings from the previous study resulted in consequential research needs for more specific investigation of high-RAP mixtures with rejuvenators in order to achieve realistic implementation into future high-RAP paving projects in Nebraska. This study thus aimed to investigate the effects of type, dosage, and treating methods of rejuvenators when they are added in aged asphalt materials. To meet the goal, we used the three rejuvenators (R1, R2, and R3) by conducting various binder-level and mixture-level tests in this study. For the binder-level testing, the performance grading (PG) method was used to primarily determine proper dosages targeting desired binder grades, and two chemical tests (i.e., Fourier Transform Infrared and Saturates-Aromatics-Resins-Asphaltenes analysis) were also conducted to examine chemical characteristics altered by rejuvenation and further aging process. The selected dosage levels from the binder testing were then applied to asphalt concrete (AC) mixture-level performance evaluation by conducting two tests: flow number for rutting and semicircular bending fracture with and without moisture conditioning for cracking. AC mixtures treated with rejuvenators at the dosage levels selected from the binder PG testing showed improved fracture resistance compared to unrejuvenated mixtures. Test-analysis results also indicated that PG binder testing, although it can successfully determine the proper dosage range of rejuvenators, is limited by only assessing the effects of rejuvenators in mechanical properties, which can be better aided by integrating chemical characterization that provides a more in-depth material-specific rejuvenation process. In addition, it appears that rejuvenation methods (e.g., blending and/or curing) can alter performance of aged mixtures. Therefore, the selection of rejuvenators and their implementation into practice should be carried out by considering multiple aspects not only by its PG recovery

    New Mixture Additives for Sustainable Bituminous Pavements

    Get PDF
    In an effort to improve mechanical properties of asphalt concrete, an exploratory research using mixture additives was attempted. Two different types of additives on two material scales were used: asphalt concrete (AC) level and binder level. At the start of this study, the effect of natural cornhusk fibers on the resistance of two types of AC mixtures on cracking were tested for hot-mix asphalt (HMA) and cold-mix asphalt (CMA). The results showed slight improvements in cracking resistance in cornhusk reinforced HMA, and in the case of the CMA, marshal flow. Overall, based on the test results, cornhusk-reinforced HMA and CMA may not significantly improve critical mechanical properties given the added cost of fibers. In addition, cornhusk fibers proved difficult to properly disperse in HMA and CMA when mixed in laboratory. However, when fibers were mixed in an asphalt production plant, the fibers appeared to become more distributed. The second part of this study, two different types of carbon nano-fillers (F1 and F2) with different surface properties and sizes were added to two different asphalt binders: the base binder and the polymer modified binder. Also, mastic samples were prepared by replacing parts of the limestone filler by the carbon nano-fillers. It was observed that the nanoscale additives interacted with the binder quite differently. Additive F1 did not show a drastic improvement in the mechanical properties, fatigue resistance, and rutting resistance of the base and polymer modified binder at the mastic and the binder scale; however, additive F2 improved all the above- mentioned properties. From the experimental investigation, it can be inferred that part of the polymer modification can be replaced by additive F2. Although additive F1 showed a minimal change, it could be useful in improving the secondary application of the pavement, such as the electrical conductivity, thermal conductivity, and absorption of radiation for energy storage, which was not the scope of this study but appears worthy to investigate

    Evaluation of Thin Asphalt Overlay Pavement Preservation in Nebraska: Laboratory Tests, MEPDG, and LCCA (17-2624)

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    Thin asphalt overlays offer an economical resurfacing, preservation, and renewal paving solution for roads that require safety and smoothness improvements. Recently, thin asphalt overlays have been used in Nebraska as a promising pavement preservation technique that needs evaluations

    Comparing probabilistic and statistical methods in landslide susceptibility modeling in Rwanda/Centre-Eastern Africa

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    Application of suitable methods to generate landslide susceptibility maps (LSM) can play a key role in risk management. Rwanda, located in centre-eastern Africa experiences frequent and intense landslides which cause substantial impacts. The main aim of the current study was to effectively generate susceptibility maps through exploring and comparing different statistical and probabilistic models. These included weights of evidence (WoE), logistic regression (LR), frequency ratio (FR) and statistical index (SI). Experiments were conducted in Rwanda as a study area. Past landslide locations have been identified through extensive field surveys and historical records. Totally, 692 landslide points were collected and prepared to produce the inventory map. This was applied to calibrate and validate the models. Fourteen maps of conditioning factors were produced for landslide susceptibility modeling, namely: elevation, slope degree, topographic wetness index (TWI), curvature, aspect, distance from rivers and streams, distance to main roads, lithology, soil texture, soil depth, topographic factor (LS), land use/land cover (LULC), precipitation and normalized difference vegetation index (NDVI). Thus, the produced susceptibility maps were validated using the receiver operating characteristic curves (ROC/AUC). The findings from this study disclosed that prediction rates were 92.7%, 86.9%, 81.2% and 79.5% respectively for WoE, FR, LR and SI models. The WoE achieved the highest AUC value (92.7%) while the SI produced a lowest AUC value (79.5%). Additionally, 20.42% of Rwanda (5048.07 km2) was modeled as highly susceptible to landslides with the western part the highly susceptible comparing to other parts of the country. Conclusively, the comparison of produced maps revealed that all applied models are promising approaches for landslide susceptibility studying in Rwanda. The results of the present study may be useful for landslide risk mitigation in the study area and in other areas with similar terrain and geomorphological conditions. More studies should be performed to include other important conditioning factors that exacerbate increases in susceptibility especially anthropogenic factors. © 201

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
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