Change in the room temperature magnetic property of ZnO upon Mn doping

We present in this paper the changes in the room temperature magnetic property of ZnO on Mn doping prepared using solvo-thermal process. The zero field cooled (ZFC) and field cooled (FC) magnetisation of undoped ZnO showed bifurcation and magnetic hysteresis at room temperature. Upon Mn doping the magnetic hysteresis at room temperature and the bifurcation in ZFC-FC magnetization vanishes. The results seem to indicate that undoped ZnO is ferromagnetic while on the other hand the Mn doped ZnO is not a ferromagnetic system. We observe that on addition of Mn atoms the system shows antiferromagnetism with very giant magnetic moments.Comment: 5 figure

Doppler study (cerebroplacental ratio) as a predictor of adverse perinatal outcome

Background: Objective of the current study was to determine the importance of Doppler screening (cerebroplacental ratio i.e. CPR) in antenatal mothers and its effect on perinatal outcome of the baby so that appropriate management can be planned effectively for a better reduction in perinatal mortality and morbidity.Methods: A prospective study conducted on hundred antenatal women in GMKMCH, Salem with gestational age >32 weeks, with singleton pregnancies. Doppler ultrasonogram of fetal middle cerebral artery and umbilical artery and thus CPR obtained.Results: 25 out of the 100 patients in the study had CPR1 helps to rule out adverse perinatal outcomes. When CPR<1, it acts as an effective tool in helping the obstetrician to decide on the mode of delivery to ensure that the baby is delivered within 12 hours of diagnosis, to improve the perinatal outcome of the baby

Amniotic fluid optical density at spontaneous onset of labour and it’s correlation with gestational age, birth weight and functional maturity of newborn

Background: Respiratory distress is the common cause of neonatal morbidity and mortality. Babies born even at 40 weeks of gestation developed respiratory distress. The maturity of newborn is independent of gestational age and birth weight of newborn. In this study amniotic fluid optical density (AFOD) is correlated with the functional maturity of newborn.Methods: In this study, hundred singleton pregnant women who underwent first trimester scan and crown rump length estimation, and who were on spontaneous labor were selected for this observational study. Under aseptic precautions AF samples were collected while doing amniotomy with 2 ml disposable syringe, also collected during caesarean section after careful hysterotomy from the bulging membranes. Amniotic fluid optical density studied with spectrometer at 650 nm. Birth weights were recorded for all the babies. Babies are also looked for the respiratory distress, NICU admission.Results: In this study, respiratory distress was reported in 28% of newborns whereas 72% of newborns did not have distress. In the present study, 27% of newborns were admitted in NICU where as 73% of the newborns were on mother’s side following delivery. Babies with AFOD 0.98±0.27 were functionally mature, skin was pleased brown in colour with little vernix, none of them had respiratory distress. Amniotic fluid optical density <0.4 developed respiratory distress.Conclusions: Amniotic fluid optical density is a simple method to assess the functional maturity of newborn

The accuracy of free-hand cup positioning: a CT based measurement in a South Indian hospital

Background: In total hip arthroplasty, the restoration of normal hip center in acetabular reconstruction encourages the normal bio mechanics. The impingement, dislocation, and implant wear have increased the interest in accurate component placement in arthroplasty. This study is to determine the accuracy of the free hand technique in the acetabular cup placement in relation to native acetabulam using CT scan images.Methods: This study was done in the Coimbatore Medical College and Hospital from June 2015 to March 2016. Twenty patients who have undergone total hip replacements were subjected to CT scan of pelvis preoperatively and postoperatively. The acetabular cup version and the inclination were measured and analyzed statistically.Results: The mean acetabular version was 17.5◦±6.5◦ and the inclination was 46.6◦±9.3◦ pre operatively. Post operatively the mean acetabular version was 26.3◦±17.3◦ and the inclination was 41.7◦±10.9◦. With reference to the component version it ranged from 12.5˚ of retroversion to 62.5˚ anteversion with a mean of 26.3◦±17.3◦. The component inclination ranged from 15.6◦ to 58.4◦ with a mean of 41.7◦±10.9◦. On combining component version and inclination, only (50%) was within the safe zone.Conclusions: Based on the CT finding acetabular version and inclination differs from individual to individual. During acetabular cup placement in total hip arthroplasty using free hand technique, our study shows that that inclination is better achieved and the anteversion is over targeted in most of the cases

Switching on electrocatalytic activity in solid oxide cells

Solid oxide cells (SOCs) can operate with high efficiency in two ways - as fuel cells, oxidizing a fuel to produce electricity, and as electrolysis cells, electrolysing water to produce hydrogen and oxygen gases. Ideally, SOCs should perform well, be durable and be inexpensive, but there are often competitive tensions, meaning that, for example, performance is achieved at the expense of durability. SOCs consist of porous electrodes - the fuel and air electrodes - separated by a dense electrolyte. In terms of the electrodes, the greatest challenge is to deliver high, long-lasting electrocatalytic activity while ensuring cost- and time-efficient manufacture. This has typically been achieved through lengthy and intricate ex situ procedures. These often require dedicated precursors and equipment; moreover, although the degradation of such electrodes associated with their reversible operation can be mitigated, they are susceptible to many other forms of degradation. An alternative is to grow appropriate electrode nanoarchitectures under operationally relevant conditions, for example, via redox exsolution. Here we describe the growth of a finely dispersed array of anchored metal nanoparticles on an oxide electrode through electrochemical poling of a SOC at 2 volts for a few seconds. These electrode structures perform well as both fuel cells and electrolysis cells (for example, at 900 °C they deliver 2 watts per square centimetre of power in humidified hydrogen gas, and a current of 2.75 amps per square centimetre at 1.3 volts in 50% water/nitrogen gas). The nanostructures and corresponding electrochemical activity do not degrade in 150 hours of testing. These results not only prove that in operando methods can yield emergent nanomaterials, which in turn deliver exceptional performance, but also offer proof of concept that electrolysis and fuel cells can be unified in a single, high-performance, versatile and easily manufactured device. This opens up the possibility of simple, almost instantaneous production of highly active nanostructures for reinvigorating SOCs during operation

An economic evaluation of implementing a decentralized dengue screening intervention under the National Vector Borne Disease Control Programme in Tamil Nadu, South India.

BACKGROUND Lack of effective early screening is a major obstacle for reducing the fatality rate and disease burden of dengue. In light of this, the government of Tamil Nadu has adopted a decentralized dengue screening strategy at the primary healthcare (PHC) facilities using blood platelet count. Our objective was to determine the cost-effectiveness of a decentralized screening strategy for dengue at PHC facilities compared with the current strategy at the tertiary health facility (THC) level. METHODS Decision tree analysis followed a hypothetical cohort of 1000 suspected dengue cases entering the model. The cost-effectiveness analysis was performed at a 3% discount rate for the proposed and current strategy. The outcomes are expressed in incremental cost-effectiveness ratios (ICERs) per quality-adjusted life years gained. One-way sensitivity analysis and probabilistic sensitivity analysis were done to check the uncertainty in the outcome. RESULTS The proposed strategy was found to be cost-saving and ICER was estimated to be -41 197. PSA showed that the proposed strategy had a 0.84 probability of being an economically dominant strategy. CONCLUSIONS The proposed strategy is cost-saving, however, it is recommended to consider optimal population coverage, costs to economic human resources and collateral benefits of equipment

Exsolution trends and co-segregation aspects of self-grown catalyst nanoparticles in perovskites

In perovskites, exsolution of transition metals has been proposed as a smart catalyst design for energy applications. Although there exist transition metals with superior catalytic activity, they are limited by their ability to exsolve under a reducing environment. When a doping element is present in the perovskite, it is often observed that the surface segregation of the doping element is changed by oxygen vacancies. However, the mechanism of co-segregation of doping element with oxygen vacancies is still an open question. Here we report trends in the exsolution of transition metal (Mn, Co, Ni and Fe) on the PrBaMn2O5+?? layered perovskite oxide related to the co-segregation energy. Transmission electron microscopic observations show that easily reducible cations (Mn, Co and Ni) are exsolved from the perovskite depending on the transition metal-perovskite reducibility. In addition, using density functional calculations we reveal that co-segregation of B-site dopant and oxygen vacancies plays a central role in the exsolution

Oxygen deficient layered double perovskite as an active cathode for CO2 electrolysis using a solid oxide conductor

A-site ordered PrBaMn2O5+?? was investigated as a potential cathode for CO2 electrolysis using a La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) electrolyte. The A-site ordered layered double perovskite, PrBaMn2O5+??, was found to enhance electrocatalytic activity for CO2 reduction on the cathode side since it supports mixed valent transition metal cations such as Mn, which could provide high electrical conductivity and maintain a large oxygen vacancy content, contributing to fast oxygen ion diffusion. It was found that during the oxidation of the reduced PrBaMn2O5+?? (O5 phase) to PrBaMn2O6-?? (O6 phase), a reversible oxygen switchover in the lattice takes place. In addition, here the successful CO2 electrolysis was measured in LSGM electrolyte with this novel oxide electrode. It was found that this PrBaMn2O5+??, layered perovskite cathode exhibits a performance with a current density of 0.85 A cm-2 at 1.5 V and 850 ??C and the electrochemical properties were also evaluated by impedance spectroscopy.open0

Cation-swapped homogeneous nanoparticles in perovskite oxides for high power density

Exsolution has been intensively studied in the fields of energy conversion and storage as a method for the preparation of catalytically active and durable metal nanoparticles. Under typical conditions, however, only a limited number of nanoparticles can be exsolved from the host oxides. Herein, we report the preparation of catalytic nanoparticles by selective exsolution through topotactic ion exchange, where deposited Fe guest cations can be exchanged with Co host cations in PrBaMn1.7Co0.3O5+delta. Interestingly, this phenomenon spontaneously yields the host PrBaMn1.7Fe0.3O5+delta, liberating all the Co cations from the host owing to the favorable incorporation energy of Fe into the lattice of the parent host (Delta E-incorporation = -0.41 eV) and the cation exchange energy (Delta E-exchange = -0.34 eV). Remarkably, the increase in the number of exsolved nanoparticles leads to their improved catalytic activity as a solid oxide fuel cell electrode and in the dry reforming of methane