Mechanical and Microstructure Study of Nickel-Based ODS Alloys Processed by Mechano-Chemical Bonding and Ball Milling

Due to the need to increase the efficiency of modern power plants, land-based gas turbines are designed to operate at high temperature creating harsh environments for structural materials. The elevated turbine inlet temperature directly affects the materials at the hottest sections, which includes combustion chamber, blades, and vanes. Therefore, the hottest sections should satisfy a number of material requirements such as high creep strength, ductility at low temperature, high temperature oxidation and corrosion resistance. Such requirements are nowadays satisfied by implementing superalloys coated by high temperature thermal barrier coating (TBC) systems to protect from high operating temperature required to obtain an increased efficiency. Oxide dispersive strengthened (ODS) alloys are being considered due to their high temperature creep strength, good oxidation and corrosion resistance for high temperature applications in advanced power plants. These alloys operating at high temperature are subjected to different loading systems such as thermal, mechanical, and thermo-mechanical combined loads at operation. Thus, it is critical to study the high temperature mechanical and microstructure properties of such alloys for their structural integrity.;The primary objective of this research work is to investigate the mechanical and microstructure properties of nickel-based ODS alloys produced by combined mechano-chemical bonding (MCB) and ball milling subjected to high temperature oxidation, which are expected to be applied for high temperature turbine coating with micro-channel cooling system. Stiffness response and microstructure evaluation of such alloy systems was studied along with their oxidation mechanism and structural integrity through thermal cyclic exposure. Another objective is to analyze the heat transfer of ODS alloy coatings with micro-channel cooling system using finite element analysis (FEA) to determine their feasibility as a stand-alone structural coating.;During this project it was found that stiffness response to increase and remain stable to a certain level and reduce at latter stages of thermal cyclic exposure. The predominant growth and adherent Ni-rich outer oxide scale was found on top of the alumina scale throughout the oxidation cycles. The FEA analysis revealed that ODS alloys could be potential high temperature turbine coating materials if micro-channel cooling system is implemented

Evaluation of soil solarisation and bio-fumigation for the management of bacterial spot of tomato

Soil-borne plant pathogens cause heavy losses to all major crops, leading to reductions in both yield and quality. Soil solarisation and bio-fumigation offer disease management options that are safe and reduce the use of pesticides for soil-borne plant pathogens. Mustard plant releases antimicrobial hydrolysis products, notably isothiocyanates when used as a bio-fumigant. Bacterial spot of tomato caused by Xanthomonas campestris pv. vesicatoria (Xcv) can survive in soil and plant debris, which serve as a primary inoculum for infecting the next tomato crop. An experiment was carried out with the objective of evaluating effects of soil solarisation and the use of Ethiopian mustard (Brassica carinata A. Braun) as a bio-fumigant to control bacterial spot disease and on yield of tomato. The treatments consisted of six types of potted soil medium (solarised at Haramaya and Dire Dawa, bio-fumigated, biofumigated as well as solarised at Haramaya and Dire Dawa, and untreated control as non-solarised non-biofumigated pots). Treated tomato seeds were planted and fruit yields were compared among treatments. Potted soil was inoculated with the pathogen, Xcv, belonging to T2P2 race group. The total microbial and Xcv counts were done before as well as after setting up the experiment. The results revealed that solarisation reduced the population of Xcv from 10.68 to 8.79 CFU g-1, total bacterial population from 11.27 to 9.86 CFU g-1, and total actinomycete counts from 11.69 to 9.44 CFU g-1 while bio-fumigation had a non-significant effect on Xcv and total microbial counts. None of the treatments exhibited a significant effect on fungal counts. The fruit yield of tomato grown on biofumigated as well as solarised soil was the highest (91.18 t ha-1) as compared to the other treatments. It can, therefore, be concluded that solarisation and bio-fumigation cannot be used as a bio-rational option for effective management of Xcv on tomato but the two methods could be used to increase tomato yield in the presence of the pathogen.Key words: bio-fumigation, solarisation, bacterial leaf spo

Use of geographic information system and water quality index to assess suitability of groundwater quality for drinking purposes in Hewane areas, Tigray, Northern Ethiopia

The study area Hewane is situated in the southern zone of Tigray Regional State, Hintalo Wajirat wereda. It is geographically located between 1444000 to 1454000m N and 550000 to 558000m E with an aerial extent of 47.66 sq. km. The study was conducted having an objective of assessing suitability of groundwater quality for drinking purposes through geographic information system (GIS) and water quality index (WQI). Ten groundwater samples were collected from the study area and 13 physicochemical parameters such as TDS, TH, Alkalinity, pH, EC, Temperature, Na+, K+, Mg2+,Ca2+, Cl-, HCO3- and SO42- were analyzed. Inverse distance weighted (IDW) interpolation method has been used to generate the spatial distribution of the groundwater physico-chemical parameters and water quality index map. To estimate the water quality index, 9 parameters have been considered: pH, Na+, K+, Mg2+,Ca2+, Cl-, HCO3-, SO42-, and TDS. The WQI estimated for the groundwater samples of the study area ranges from 86.1 to 180.5 at groundwater samples GWS_2 and GWS_5, respectively. Based on the analysis, most of the area under study falls 70% in poor water class and 30% in good water class. Hence, the result revealed that 70% of the groundwater samples of the study area are hardly suitable for drinkingpurposes without water quality management activities.Key words: spatial distribution, GIS, WQI, groundwater quality, Hewane, Tigray, Ethiopi

Constrained evolution of effective equation of state parameter in non-linear f(R,Lm)f(R, L_m) dark energy model: Insights from Bayesian analysis of cosmic chronometers and Pantheon samples

We conduct a Bayesian analysis of recent observational datasets, specifically the Cosmic Chronometers (CC) dataset and Pantheon samples, to investigate the evolution of the EoS parameter in dark energy models. Our study focused on the effective EoS parameter, which is described by the parametric form $\omega_{eff}=-\frac{1}{1+m(1+z)^n}$, where $m$ and $n$ are model parameters. This parametric form is applicable within the framework of $f(R,L_m)$ gravity, where $R$ represents the Ricci scalar and $L_m$ is the matter Lagrangian. Here, we examine a non-linear $f(R,L_m)$ model characterized by the functional form $f(R,L_m)=\frac{R}{2}+L_m^\alpha$, where $\alpha$ is the free parameter of the model. We examine the evolution of several cosmological parameters, including the effective EoS parameter $\omega_{eff}$, the deceleration parameter $q$, the density parameter $\rho$, the pressure $p$, and the statefinder parameters. Our analysis revealed that the constrained current value of the effective EoS parameter, $\omega_{eff}^{0}=-0.68\pm0.06$ for both the CC and Pantheon datasets, points towards a quintessence phase. Moreover, at redshift $z=0$, the deceleration parameter, $q_0 = -0.61^{+0.01}_{-0.01}$, indicates that the present Universe is undergoing accelerated expansion.Comment: The European Physical Journal Plus published versio

Global, regional, and national levels of maternal mortality, 1990–2015 : a systematic analysis for the Global Burden of Disease Study 2015

Background In transitioning from the Millennium Development Goal to the Sustainable Development Goal era, it is imperative to comprehensively assess progress toward reducing maternal mortality to identify areas of success, remaining challenges, and frame policy discussions. We aimed to quantify maternal mortality throughout the world by underlying cause and age from 1990 to 2015. Methods We estimated maternal mortality at the global, regional, and national levels from 1990 to 2015 for ages 10–54 years by systematically compiling and processing all available data sources from 186 of 195 countries and territories, 11 of which were analysed at the subnational level. We quantifi ed eight underlying causes of maternal death and four timing categories, improving estimation methods since GBD 2013 for adult all-cause mortality, HIVrelated maternal mortality, and late maternal death. Secondary analyses then allowed systematic examination of drivers of trends, including the relation between maternal mortality and coverage of specifi c reproductive health-care services as well as assessment of observed versus expected maternal mortality as a function of Socio-demographic Index (SDI), a summary indicator derived from measures of income per capita, educational attainment, and fertility. Findings Only ten countries achieved MDG 5, but 122 of 195 countries have already met SDG 3.1. Geographical disparities widened between 1990 and 2015 and, in 2015, 24 countries still had a maternal mortality ratio greater than 400. The proportion of all maternal deaths occurring in the bottom two SDI quintiles, where haemorrhage is the dominant cause of maternal death, increased from roughly 68% in 1990 to more than 80% in 2015. The middle SDI quintile improved the most from 1990 to 2015, but also has the most complicated causal profi le. Maternal mortality in the highest SDI quintile is mostly due to other direct maternal disorders, indirect maternal disorders, and abortion, ectopic pregnancy, and/or miscarriage. Historical patterns suggest achievement of SDG 3.1 will require 91% coverage of one antenatal care visit, 78% of four antenatal care visits, 81% of in-facility delivery, and 87% of skilled birth attendance. Interpretation Several challenges to improving reproductive health lie ahead in the SDG era. Countries should establish or renew systems for collection and timely dissemination of health data; expand coverage and improve quality of family planning services, including access to contraception and safe abortion to address high adolescent fertility; invest in improving health system capacity, including coverage of routine reproductive health care and of more advanced obstetric care—including EmOC; adapt health systems and data collection systems to monitor and reverse the increase in indirect, other direct, and late maternal deaths, especially in high SDI locations; and examine their own performance with respect to their SDI level, using that information to formulate strategies to improve performance and ensure optimum reproductive health of their population.GBD 2015 Maternal Mortality Collaborators ...Nicholas J Kassebaum ... Azmeraw T Amare ... Liliana G Ciobanu ... James Hancock ... Ratilal Lalloo ... Yohannes Adama Melaku ... John Nelson Opio ... G A Tessema ... et.al

The genetic relationship between female reproductive traits and six psychiatric disorders

Female reproductive behaviours have important implications for evolutionary fitness and health of offspring. Here we used the second release of UK Biobank data (N = 220,685) to evaluate the association between five female reproductive traits and polygenic risk scores (PRS) projected from genome-wide association study summary statistics of six psychiatric disorders (N = 429,178). We found that the PRS of attention-deficit/hyperactivity disorder (ADHD) were strongly associated with age at first birth (AFB) (genetic correlation of -0.68 ± 0.03), age at first sexual intercourse (AFS) (-0.56 ± 0.03), number of live births (NLB) (0.36 ± 0.04) and age at menopause (-0.27 ± 0.04). There were also robustly significant associations between the PRS of eating disorder (ED) and AFB (0.35 ± 0.06), ED and AFS (0.19 ± 0.06), major depressive disorder (MDD) and AFB (-0.27 ± 0.07), MDD and AFS (-0.27 ± 0.03) and schizophrenia and AFS (-0.10 ± 0.03). These associations were mostly explained by pleiotropic effects and there was little evidence of causal relationships. Our findings can potentially help improve reproductive health in women, hence better child outcomes. Our findings also lend partial support to the evolutionary hypothesis that causal mutations underlying psychiatric disorders have positive effects on reproductive success.Guiyan Ni, Azmeraw T. Amare, Xuan Zhou, Natalie Mills, Jacob Gratten, S. Hong Le

The synergy between TB and HIV co-infection on perceived stigma in Ethiopia

<p>Abstract</p> <p>Background</p> <p>The synergy between tuberculosis (TB) and human immunodeficiency virus (HIV) co-infection on perceived stigma is not well studied. The objective of this study was to assess the effect of TB/HIV co-infection on perceived stigma in selected hospitals of Oromiya region, Ethiopia. A cross sectional study was conducted from February to April, 2009 in Adama, Nekemet and Jimma Specialized hospitals. Data were collected by trained HIV counselors. A structured questionnaire which consisted of socio-demographic variables, clinical information, perceived stigma, and depression was used to collect the data</p> <p>Findings</p> <p>A total of 591 participants were included in the study of whom 124 (20.9%) were co-infected with TB/HIV. The stigma items were highly reliable (Cronbach's alpha = 0.93) and had strong inter dimension correlation. Respondents who were co-infected with TB and HIV were more likely to have perceived stigma compared to non-co-infected HIV patients, [OR = 1.4, (95% CI: 1.2, 2.0)]. Non-literate individuals [OR = 1.9, (95% CI: 1.2, 3.0)] and females [OR = 1.6, (95% CI: 1.2, 2.3)] had also more perceived stigma.</p> <p>Conclusions</p> <p>TB/HIV co-infected patients, non-literate individuals and females were more likely to have high perceived stigma. Behavioral Change Communication should focus on these segments of the population to rectify the high perceived stigma.</p

Worldwide Survey of the "Assessing Pain, Both Spontaneous Awakening and Breathing Trials, Choice of Drugs, Delirium Monitoring/Management, Early Exercise/Mobility, and Family Empowerment" (ABCDEF) Bundle

OBJECTIVES: To assess the knowledge and use of the Assessment, prevention, and management of pain; spontaneous awakening and breathing trials; Choice of analgesia and sedation; Delirium assessment; Early mobility and exercise; and Family engagement and empowerment (ABCDEF) bundle to implement the Pain, Agitation, Delirium guidelines. DESIGN: Worldwide online survey. SETTING: Intensive care. INTERVENTION: A cross-sectional online survey using the Delphi method was administered to intensivists worldwide, to assess the knowledge and use of all aspects of the ABCDEF bundle. MEASUREMENT AND MAIN RESULTS: There were 1,521 respondents from 47 countries, 57% had implemented the ABCDEF bundle, with varying degrees of compliance across continents. Most of the respondents (83%) used a scale to evaluate pain. Spontaneous awakening trials and spontaneous breathing trials are performed in 66% and 67% of the responder ICUs, respectively. Sedation scale was used in 89% of ICUs. Delirium monitoring was implemented in 70% of ICUs, but only 42% used a validated delirium tool. Likewise, early mobilization was "prescribed" by most, but 69% had no mobility team and 79% used no formal mobility scale. Only 36% of the respondents assessed ICU-acquired weakness. Family members were actively involved in 67% of ICUs; however, only 33% used dedicated staff to support families and only 35% reported that their unit was open 24 hr/d for family visits. CONCLUSIONS: The current implementation of the ABCDEF bundle varies across individual components and regions. We identified specific targets for quality improvement and adoption of the ABCDEF bundle. Our data reflect a significant but incomplete shift toward patient- and family-centered ICU care in accordance with the Pain, Agitation, Delirium guidelines