Search

Li3Fe2(PO4)3 is interesting because of its technological application and environmentally benign nature. Nanocrystalline Li3Fe2(PO4)3 is synthesized by a solution combustion technique. The role of fuels/complexing agents in deciding the structural parameters and ac electrical behavior is investigated in this study. Antiferromagnetic nature and direct bandgap energy of 3.09 eV are recognized in the material. Enhanced conduction is established through mobility of Li+ ion in four co-ordination in the modified monoclinic symmetry and high temperature stability through orthorhombic symmetry. Quality of electrical data is confirmed through a Kramers-Kronig test and electrical relaxation parameters are obtained from modulus analysis. Scaling analysis of modulus data confirmed the time-temperature superposition principle. [ABSTRACT FROM AUTHOR]

The dielectric properties of nanocrystalline Ni0.5Zn0.5Fe2O4 spinel ferrite with various grain sizes, obtained by mechanically milling, have been studied using impedance measurements in the frequency range from 1 Hz to 10 MHz and in the temperature range from 300 to 823 K. The effect of milling, frequency, and temperature on the dielectric properties of nanocrystalline Ni-Zn ferrite is discussed. The real part of dielectric constant ([variant_greek_epsilon]′) for the 14 nm grain size sample is found to be about an order of magnitude smaller than that of the bulk nickel zinc ferrite. The anomalous frequency dependence of [variant_greek_epsilon]′ has been explained on the basis of hopping of both electrons and holes. The unusual increase in dielectric loss with milling is because of the increase in electrical conductivity due to oxygen vacancies introduced upon milling. The electrical modulus has been fitted to a stretched exponential function and the results clearly reveal the presence of the non-Debye type of dielectric relaxation in this material. The relaxation frequency is observed to decrease with milling due to increasing interaction between charge carriers arising out of oxygen vacancies introduced by milling. The mechanism for the electrical conduction is found to be the same as that for the dielectric polarization. [ABSTRACT FROM AUTHOR]

The temperature dependent electrical properties of graphene oxide prepared by the modified Hummers method are investigated using broadband dielectric spectroscopy. The morphology and structure are confirmed by X-ray diffraction pattern and scanning electron microscope images. In the present work, we have studied the electrical properties of graphene oxide employing a recently proposed novel approach of the combined conduction and dielectric Cole-Cole formalism. The extracted dc conductivity values varies from 1.9 × 10−8 to 3.5 × 10− 5 S cm−1 as a function of temperature (153-353 K), show power-law behaviour, which is explained through Mott’s variable range hopping conduction mechanism. The density of states was found to be 6.02 × 1018 cm−3 eV−1. The conduction relaxation timescales and dielectric relaxation timescales of GO are following the power law. The physical origin of the non-Arrhenius dc conductivity behaviour of charge carriers is explained through structural heterogeneity in graphene oxide introduced due to sp2 and sp3 hybridization of carbon atoms. The range of hop was calculated to be 4.7-3.8 nm with hopping energy changing from 0.37 to 0.69 eV as a function of temperature. [ABSTRACT FROM AUTHOR]

Summary: This study assessed the short‐run impact to poultry farmers, duck hatcheries, control costs, compensation paid to stakeholders (transfer payments) and market reactions on own and substitute product prices and backwater tourism (boat operators) due to avian influenza (AI) outbreaks in Kuttanad region of Kerala, India, during 2014. The primary data from 91 poultry farms (duck farms, broiler chicken and backyard poultry), four hatcheries and 90 backwater boat owners were collected through pre‐tested schedules. The secondary data on transfer payments and expenditure incurred to control AI were collected from developmental departments and were analysed. The estimated loss (culling live birds, eggs and feed destruction) per duck farm was USD 9,181, USD 3,889 and USD 156 in case of commercial farms reared for meat, dual‐purpose and backyard farms, respectively. The loss incurred by small‐scale broiler and backyard poultry farms was USD 453 and USD 40, respectively. The loss incurred by large and small duck hatcheries was USD 11,963 and USD 5,790, respectively, due to culling of hatchlings, young birds and destroying eggs. The government invested USD 744,890 to contain the disease spread through massive culling, surveillance and monitoring of poultry and humans due to zoonotic nature of the disease. A sharp market reaction on own and substitute product prices and eight weeks’ time lag in price recovery was observed. The consequential impact on tourism especially for the backwater boat operators amounted to a loss of USD 2,280/boat due to fall in tourist inflow. Since, control measures are post‐incidence, it is necessary to adopt appropriate preventive bio‐security measures at the farm level besides periodical screening of domestic birds in migratory birds’ flyway locations like Kuttanad to reduce the AI burden on various stakeholders including government. [ABSTRACT FROM AUTHOR]

In this present work, Li2FeZrO4 has been synthesized by hydrothermal method. The material is characterized using XRD, TGA, FTIR, UV–Vis, VSM and impedance spectroscopy. The powder XRD patterns of Li2FeZrO4 sintered at 800 °C shows that these crystallites are stable in room temperature with tetragonal structure of space group p141 and the average crystallites size is found to be 38 nm. Due to its structural stability, ac electrical properties in terms of complex Impedance Z*(ω), complex permittivity ε*(ω), complex conductivity σ*(ω) and complex electric modulus M*(ω) of the sample have been evaluated as a function of frequency at different temperatures. The shape of the impedance spectra reveals the non-Debye nature of the relaxation processes of the present material. The relaxation process consists of two different polarization processes i.e., hopping charge polarization (“pinned dipole”) and dielectric dipolar like polarization (“free dipole”) mechanism. The dc conductivity activation energy Eσ has been calculated for the material along with the activation energy for hopping conduction and dielectric relaxation. Magnetic properties have been investigated by vibrating sample magnetometer (VSM) for the sample at various temperatures. [ABSTRACT FROM AUTHOR]

This study was conducted to assess the impact of Foot-and-mouth Disease ( FMD) outbreak in cattle and buffaloes on farming community in Kolar district, Karnataka state, India. Primary data were collected using pre-tested schedule from 178 sample farms using multistage random cluster sample technique. The results revealed that 78% of surveyed villages were affected with FMD. The FMD incidence risk was high across the herd sizes, whereas the mortality risk was high in small herds. In indigenous cattle, the highest loss due to FMD was distress sale (208 USD) followed by other losses, whereas, in Crossbred cattle, the highest loss was mortality loss (515 USD) followed by distress sale (490 USD), milk yield loss (327 USD), treatment cost (38 USD) and extra labour engagement expenses for nursing of FMD-affected bovines (30 USD). In local and upgraded buffaloes, the mean total loss per affected animal was 440 USD and 513 USD, respectively. A very high variability in the loss per animal was observed across the type of losses in the Crossbred cattle, and it may be due to differences in age of the FMD-infected animal, value of the animal, milking stage, lactation levels, herd sizes and labour engagement levels, etc. In local and upgraded buffaloes, the mean total loss per animal was 639 USD and 1008 USD, respectively. The sensitivity analysis for 5% change in price revealed that the mean total loss per animal was positively correlated with price. Further, the social impact elicitation revealed that majority of the livestock owners perceived FMD had caused permanent asset loss, which in turn increased psychological stress of the family. The estimated losses and social impact due to FMD signify the importance of the intervention to control the disease and thus socio-economic gain to the farmer and society at large. [ABSTRACT FROM AUTHOR]