RESUMEN
Bi0.80Ba0.20Fe1-xTixO3 ( 0 ≤ x ≤ 0.10 ) samples are prepared using solid state reaction technique. Bi3+ site is replaced with 20 % Ba2+ which induced structural modification from rhombohedral to pseudo cubic accompanied by the creation of oxygen vacancies owing to the charge reimbursement. Fe3+ site is replaced with different concentrations of Ti4+ keeping Ba content fixed. All the samples exhibited similar morphology and no significant variation in grain size is observed by substituting Ti at Fe site. All of the samples exhibited ferromagnetic behavior, which is ascribed to the destruction of spiral spin structures and changes in super-exchange interaction strength caused by variations in bond lengths of Fe-O and Fe-O-Fe. The decrease in magnetization with increasing Ti concentration is due to magnetic moment dilution caused by non-magnetic Ti4+. An anomalous trend in magnetization is observed for magnetic measurements at low temperature (77 K) where structural transformation from ferromagnetic to diamagnetic behavior was noted for 10% Ti content. Further, because of the incorporation of Ti4+, an improved dielectric property was observed due to increase in resistivity and decrease in the defect concentration (oxygen vacancies). In the present study, it was concluded that optimum concentration of Ba2+ (20%) and Ti4+ co-doped BiFeO3 systems have shown enhanced multiferroic properties at room temperature.
Asunto(s)
COVID-19 , Servicios de Salud , Esquemas de Inmunización , Inmunización/estadística & datos numéricos , Vacunación , Bangladesh , Niño , Preescolar , HumanosRESUMEN
BACKGROUND: WHO does not recommend community-level health workers (CLHWs) using integrated community case management (iCCM) to treat 7-59 days old infants with fast breathing with oral amoxicillin, whereas World Health Organization (WHO) integrated management of childhood illness (IMCI) recommends it. We want to collect evidence to help harmonization of both protocols. METHODS: A cluster, randomized, open-label trial will be conducted in Africa and Asia (Ethiopia, Malawi, Bangladesh and India) using a common protocol with the same study design, inclusion criteria, intervention, comparison, and outcomes to contribute to the overall sample size. This trial will also identify hypoxaemia in young infants with fast breathing. CLHWs will assess infants for fast breathing, which will be confirmed by a study supervisor. Enrolled infants in the intervention clusters will be treated with oral amoxicillin, whereas in the control clusters they will be managed as per existing iCCM protocol. An independent outcome assessor will assess all enrolled infants on days 6 and 14 of enrolment for the study outcomes in both intervention and control clusters. Primary outcome will be clinical treatment failure by day 6. This trial will obtain approval from the WHO and site institutional ethics committees. CONCLUSIONS: If the research shows that CLHWs can effectively and safely treat fast breathing pneumonia in 7-59 days old young infants, it will increase access to pneumonia treatment substantially for infants living in communities with poor access to health facilities. Additionally, this evidence will contribute towards the review of the current iCCM protocol and its harmonization with IMCI protocol. TRIAL REGISTRATION: The trial is registered at AZNCTR International Trial Registry as ACTRN12617000857303.