A Comparative Study on Microstructure and Tensile Properties of Spray Formed and Ascast Al-28Si-5Cu-4Fe and Al-28Si-5Cu-4Mg Alloys

In the present study, Al-28Si, Al-28Si-5Cu-4Fe and Al-28Si-5Cu-4Mg alloys were produced by spray forming and subsequently hot pressed for densification. The effect of alloy composition on the microstructure and mechanical behavior of spray-formed alloys were investigated. The microstructures consist of an equiaxed, nearly spheroidized grain morphology of α-Al matrix. The spray formed alloys exhibited sharply decreased segregation and increased metastable solid solubility and greater volume fraction of Si particles and intermetallic phases. Spray formed Al-28Si-5Cu-4Fe alloy contains Al 2 Cu, Al 5 FeSi along with Si. On the other hand, Al-28Si-5Cu-4Mg alloy showed Al 2 Cu, Al 48 Si 29 Mg 18 and Si. Hot pressing lead to a significant reduction of porosity and partial recrystallization of spray formed alloys. The room temperature tensile tests of spray formed hot pressed alloys showed significant increase in ultimate tensile strength compared to as cast alloys. Spray formed hot pressed Al-28Si-5Cu-4Fe alloy exhibited superior ultimate tensile strength and significant increase in elongation to fracture. This may be attributed to the presence of homogeneous distribution of fine Si particles, high content of short needle-like β-Al 5 FeSi intermetallic and precipitation strengthening phases

Effect of Cu and Mg on the wear properties of spray formed Al -22Si alloy

In the present study, the effect of Cu and Mg on the wear behavior of spray formed Al-22Si alloy has been investigated and the same has been compared with that of its counterpart as-cast alloy. Al-22Si and Al–22Si–4Cu–1.7Mg alloys prepared by spray deposition process were hot pressed to reduce the porosity. The microstructures were examined by optical and scanning electron microscopes. The microstructure of spray formed Al-22Si alloy is fine and homogeneous and primary silicon phase distributed in the aluminum matrix evenly are fine and faceted having a mean size of 12 µm. The microstructure of spray formed Al–22Si–4Cu–1.7Mg alloy exhibited equiaxed grain morphology with fine and uniform distribution of both primary and eutectic Si with fine Q-Al-Si-Mg-Cu phase and θ-Al 2 Cu precipitates dispersed evenly in α- Al matrix. In contrast the microstructure of as-cast Al–22Si alloy consisted of coarse plates of primary Si of size 350 µm and eutectic Si needles. The as-cast Al–22Si–4Cu–1.7Mg alloy consisted of coarse primary Si with Chinese script like θ-Al 2 Cu precipitates and needles of Q-Al- Si-Mg-Cu phase in α-Al matrix. The wear study of both as-cast and spray formed and hot pressed alloys under an applied load of 10 to 50 N and sliding velocity of 0.4 to1.5 ms -1 indicated two distinct regimes of mild and severe wear. In both the regimes, the spray-formed and hot pressed alloys consistently indicated a low wear rate compared to that of as-cast alloys. The high wear resistance of spray formed and hot pressed Al–22Si and Al–22Si–4Cu–1.7Mg alloys were explained in the light of their microstructural modifications induced during spray forming and subsequent hot pressing

Wear behavior of secondary processed spray formed Al-28Si-5Cu-4Mg alloy

In the present study Al-28Si-5Cu-4Mg alloy has been spray formed and hot pressed for densification. Hot pressing refined the microstructure and reduced the porosity in the spray formed alloy from 10 to 1%. The microstructure of spray formed and hot pressed alloy exhibited equiaxed grain morphology with fine and uniform distribution of both primary and eutectic Si with fine needles of Q-Al 12 Si 7 Mg 4 Fe intermetallics and Chinese script like θ- Al 2 Cu precipitates in α-Al matrix. The size of Si particles ranged from 3–10 µm. In contrast the microstructure of as-cast alloy consisted of coarse primary and eutectic Si, long needles of Q-Al-Si-Mg-Cu-Fe phase and bright grey θ-Al 2 Cu phase in the α-Al matrix. The size of primary Si varied from 30–250 µm. The spray formed and hot pressed alloy exhibited a higher hardness compared to the as-cast alloy. The wear behavior of both the alloys, under dry sliding conditions, showed an increase in the wear rate with an increase in the load. However, the spray formed and hot pressed alloy exhibited maximum wear resistance and minimum coefficient of friction, while as-cast alloy exhibited minimum wear resistance and maximum coefficient of friction over the entire range of applied load. The high wear resistance and high hardness of spray formed and hot pressed alloy are explained in the light of its microstructural modifications induced during spray forming and subsequent hot pressing and also the topographical features of worn surfaces and morphology of debris particles

Microstructural and Hardness of Spray Deposited Al-30Mg 2 Si-2Cu Alloy in Solutionized and Aged Conditions

An Al–30Mg 2 Si- 2Cu alloy was produced by spray casting and the secondary processing such as hot compression and heat treatment were carried out. The coarsening behavior, distribution and size of the Mg 2 Si precipitates, the influence of subsequent heat treatment on the microstructure were investigated Uniform distribution of Mg 2 Si was achieved by spray casting. The hardness tests were conducted on spray deposited, secondary processed and heat treated alloys. The results indicate that spray casting has strong influence on microstructure and hardness of the material. The microstructural refinement of the alloy was enhanced during hot compression. The alloying with copper lead to further increase in strength by age hardening due to precipitation Al 2 Cu phase. A significant improvement in hardness was observed after hot compression and heat treatment

Characterization of Asian core-collection of groundnut for morphological traits

Asia region core collection with 504 accessions comprising 29 fastigiata, 230 hypogaea and 245 Vulgaris types were characterized for 14 morphological descriptors during 2000 rainy and 2000-01 post rainy seasons at Regional Research Station Raichur and Agricultural Research Station Kawadimatti, to asses the morphological diversity, to study the significant association between different traits and to know the importance of descriptor traits in the total variation. Frequency distribution of different descriptors indicated that erect type followed by procumbent-1 and decumbent-1 growth habit, alternate and sequential branching pattern, absence of stem pigmentation, subglabrous with one or two rows of hairs on the stem, light green followed by dark green leaf color, almost glabrous type of leaf surface, elliptic leaf shape, orange flower color, presence of stem pigment, 2-1 seeded pods followed by 2-3-1/2-1-3, slight to moderate beak and constriction, moderate reticulation, tan followed by red seed color dominated the core collection. The mean score for number of seeds per pod differed significantly in all three botanical varieties except growth habit, branching pattern and leaf color. But mean score for all the traits differed significantly with one or the other botanical variety. For most of the traits wider range was observed except flower color and leaf hairs and a significant association was observed between growth habit and branching pattern, growth habit and leaf color, branching pattern and leaf color in the entire collection. Between beak and pod reticulation, stem color and pod reticulation in the variety fastigiata. PCOA indicated that 12 out of 14 morphological traits exhibited significant correlation with either one of the botanical variety or with the entire collection appearing atleast once in the first five PCOA values. Shanon-Weaver diversity index revealed that flower color and leaf hairyness are monomorphic in nature. All the traits except growth habit, pod beak and pod reticulation in fastigiata and pod beak in vulgaris exhibited low diversity

Phenotypic variation for agronomic characteristics in a groundnut core collection for Asia

The groundnut (Arachis hypogaea L.) core collection for Asia consists of 504 accessions of which 274 belong to subsp. fastigiata (var. fastigiata and vulgaris) and 230 to subsp. hypogaea (var. hypogaea). This core collection was evaluated for 20 agronomic characteristics in the 2000 rainy season and for 21 characteristics in the 2000/2001 post-rainy season at two locations, Raichur and Kawadimatti, India, to estimate phenotypic diversity and determine the importance of different descriptor traits. All traits, except leaflet length and width, pod length and width, and seed length and width showed genotype × location interactions. All traits except leaflet width, number of primary branches, nodes on main stem, nodes on cotyledonary branches, total and mature pods, and length of primary and cotyledonary branches, pod length and width, and seed length and width showed genotype × season interaction. The fastigiata and hypogaea groups differed significantly for all traits except one trait each in the rainy season at Raichur and post-rainy season at Kawadimatti and five traits in the post-rainy season at Raichur. The hypogaea group took longer to flower, had more primary branches, longer primary and cotyledonary branches, more nodes on cotyledonary branches, more total pods, mature pods and pegs per plant, longer and wider pods and heavier seeds than the fastigiata group. The range for most traits was different in the two groups. There were significant phenotypic correlations among the various characteristics. Three of these, between number of total pods and mature pods, number of total pods and pegs, and number of mature pods and pegs had values greater than 0.707 (r2=50%) in both the fastigiata and hypogaea groups and in the entire regional collection. Principal component analysis showed that 20 agronomic traits were important in explaining multivariate polymorphism. Pod yield per plant did not significantly account for variation in the first five principal components of fastigiata and hypogaea types as well as for the entire regional collection in either season or location, indicating its relatively low importance as a descriptor. Average phenotypic diversity index was similar in both groups. The Shannon-Weaver diversity index varied among traits between the two groups, and the diversity within a group depended on location, season, and traits recorded

Identification of diverse groundnut germplasm through multienvironment evaluation of a core collection for Asia

In Asia, like elsewhere, the use of genetic resources has been limited in groundnut (Arachis hypogaea L.) breeding programs, resulting in a narrow genetic base of cultivars. Utilization of exotic germplasm in breeding programs is needed to enhance the diversity of cultivars. Core collections, which generally contain 10% of total accessions and represent the diversity of the entire collection, have been suggested as a means to enhance the use of genetic resources. For traits of economic importance, which often display high genotype × environment interactions, multienvironment evaluation is required to choose desirable parents. The groundnut core collection for Asia, consisting of 29 accessions of subsp. fastigiata var. fastigiata, 245 of subsp. fastigiata var. vulgaris, and 230 of subsp. hypogaea var. hypogaea, along with four control cultivars, was evaluated in multienvironments for 22 agronomic traits to select diverse superior germplasm accessions for use as parents in improvement programs. Data were recorded for 12 traits in six environments, eight traits in four environments, and for two traits in two environments. Analysis of data, using the residual maximum likelihood (REML) approach, indicated that variance components due to genotypes were significant for all 22 traits, and genotypes × environment interaction was significant for eight traits. Estimates of broad sense heritability ranged from 35.5% for pod yield per plant to 98.0% for days to cessation of flowering, indicating relative reliability of selection for different traits. On the basis of performance compared to control cultivars in different environments, 15 fastigiata, 20 vulgaris, and 25 hypogaea accessions from 14 countries were selected. The selected accessions and control cultivars were grouped using scores of the first 15 principal components (PCs) in fastigiata, 20 PCs in vulgaris, and 21 PCs in hypogaea. The clustering by Ward's method indicated that the selected accessions were diverse from the control cultivars. These 60 diverse parents will provide the germplasm, which can be used in the improvement programs to broaden the genetic base of groundnut cultivars

Trends and determinants of stillbirth in developing countries: results from the Global Network\u27s Population-Based Birth Registry.

BACKGROUND: Stillbirth rates remain high, especially in low and middle-income countries, where rates are 25 per 1000, ten-fold higher than in high-income countries. The United Nations\u27 Every Newborn Action Plan has set a goal of 12 stillbirths per 1000 births by 2030 for all countries. METHODS: From a population-based pregnancy outcome registry, including data from 2010 to 2016 from two sites each in Africa (Zambia and Kenya) and India (Nagpur and Belagavi), as well as sites in Pakistan and Guatemala, we evaluated the stillbirth rates and rates of annual decline as well as risk factors for 427,111 births of which 12,181 were stillbirths. RESULTS: The mean stillbirth rates for the sites were 21.3 per 1000 births for Africa, 25.3 per 1000 births for India, 56.9 per 1000 births for Pakistan and 19.9 per 1000 births for Guatemala. From 2010 to 2016, across all sites, the mean stillbirth rate declined from 31.7 per 1000 births to 26.4 per 1000 births for an average annual decline of 3.0%. Risk factors for stillbirth were similar across the sites and included maternal age \u3c 20 years and age \u3e 35 years. Compared to parity 1-2, zero parity and parity \u3e 3 were both associated with increased stillbirth risk and compared to women with any prenatal care, women with no prenatal care had significantly increased risk of stillbirth in all sites. CONCLUSIONS: At the current rates of decline, stillbirth rates in these sites will not reach the Every Newborn Action Plan goal of 12 per 1000 births by 2030. More attention to the risk factors and treating the causes of stillbirths will be required to reach the Every Newborn Action Plan goal of stillbirth reduction. TRIAL REGISTRATION: NCT01073475

Data quality monitoring and performance metrics of a prospective, population-based observational study of maternal and newborn health in low resource settings

BACKGROUND: To describe quantitative data quality monitoring and performance metrics adopted by the Global Network´s (GN) Maternal Newborn Health Registry (MNHR), a maternal and perinatal population-based registry (MPPBR) based in low and middle income countries (LMICs). METHODS: Ongoing prospective, population-based data on all pregnancy outcomes within defined geographical locations participating in the GN have been collected since 2008. Data quality metrics were defined and are implemented at the cluster, site and the central level to ensure data quality. Quantitative performance metrics are described for data collected between 2010 and 2013. RESULTS: Delivery outcome rates over 95% illustrate that all sites are successful in following patients from pregnancy through delivery. Examples of specific performance metric reports illustrate how both the metrics and reporting process are used to identify cluster-level and site-level quality issues and illustrate how those metrics track over time. Other summary reports (e.g. the increasing proportion of measured birth weight compared to estimated and missing birth weight) illustrate how a site has improved quality over time. CONCLUSION: High quality MPPBRs such as the MNHR provide key information on pregnancy outcomes to local and international health officials where civil registration systems are lacking. The MNHR has measures in place to monitor data collection procedures and improve the quality of data collected. Sites have increasingly achieved acceptable values of performance metrics over time, indicating improvements in data quality, but the quality control program must continue to evolve to optimize the use of the MNHR to assess the impact of community interventions in research protocols in pregnancy and perinatal health.Fil: Goudar, Shivaprasad S.. KLE University. Jawaharlal Nehru Medical College; IndiaFil: Stolka, Kristen B.. Research Triangle Institute International; Estados UnidosFil: Koso Thomas, Marion. Eunice Kennedy Shriver National Institute of Child Health and Human Development; Estados UnidosFil: Honnungar, Narayan V.. KLE University. Jawaharlal Nehru Medical College; IndiaFil: Mastiholi, Shivanand C.. KLE University. Jawaharlal Nehru Medical College; IndiaFil: Ramadurg, Umesh Y.. S. Nijalingappa Medical College; IndiaFil: Dhaded, Sangappa M.. KLE University. Jawaharlal Nehru Medical College; IndiaFil: Pasha, Omrana. Aga Khan University; PakistánFil: Patel, Archana. Indira Gandhi Government Medical College and Lata Medical Research Foundation; IndiaFil: Esamai, Fabian. University School of Medicine; KeniaFil: Chomba, Elwyn. University of Zambia; ZambiaFil: Garces, Ana. Universidad de San Carlos; GuatemalaFil: Althabe, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Carlo, Waldemar A.. University of Alabama at Birmingahm; Estados UnidosFil: Goldenberg, Robert L.. Columbia University; Estados UnidosFil: Hibberd, Patricia L.. Massachusetts General Hospital for Children; Estados UnidosFil: Liechty, Edward A.. Indiana University; Estados UnidosFil: Krebs, Nancy F.. University of Colorado School of Medicine; Estados UnidosFil: Hambidge, Michael K.. University of Colorado School of Medicine; Estados UnidosFil: Moore, Janet L.. Research Triangle Institute International; Estados UnidosFil: Wallace, Dennis D.. Research Triangle Institute International; Estados UnidosFil: Derman, Richard J. Christiana Care Health Services; Estados UnidosFil: Bhalachandra, Kodkany S.. KLE University. Jawaharlal Nehru Medical College; IndiaFil: Bose, Carl L.. University of North Carolina; Estados Unido

Breastfeeding Education Support Tool for Baby (BEST4Baby): Feasibility, Acceptability, and Preliminary Impact of an mHealth Supported Breastfeeding Peer Counselor Intervention in rural India

Objective: To evaluate the feasibility of an mHealth-supported breastfeeding peer counselor intervention implemented in rural India and the preliminary impact of the intervention on maternal breastfeeding behaviors, including exclusive breastfeeding (EBF). Methods: In this quasi-experimental pilot study, participants received either the intervention plus usual care (n = 110) or usual care alone (n = 112). The intervention group received nine in-home visits during and after pregnancy from peer counselors who provided education about and support for EBF and other optimal infant feeding practices and were aided with an mHealth tool. The control group received routine prenatal and postnatal health education. Progress notes and surveys were used to assess feasibility. Logistic regression models were used for between-group comparisons of optimal infant feeding outcomes, including EBF for 6 months. Results: The intervention was delivered as intended, maintained over the study period, and had high acceptability ratings. There were statistically significant differences in all outcomes between groups. The intervention group had a significantly higher likelihood of EBF at 6 months compared to the control group (adjusted odds ratio 3.57, 95% confidence interval 1.80–7.07). Conclusion: Integration of mHealth with community-based peer counselors to educate women about EBF is feasible and acceptable in rural India and impacts maternal breastfeeding behaviors