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The solution combustion synthesis approach was successfully used to produce rare-earth (RE) Cerium (Ce3+)-substituted Co–Ni ferrite nanoparticles having the formula Co0.5 Ni0.5 Ce0.01 Fe1.99 O4. The synthesized nanoparticles were irradiated using 60Co γ rays for 50 kGy and 100 kGy. The lattice parameter decreases with the irradiation dosage. The gas sensing responses of irradiated thin films at an ambient temperature were examined. Thin film of the sample irradiated at 100 kGy shows maximum sensing response for methane gas. The sensing responses and recovery times were recorded. According to the stability investigation, the sensing response of 100 kGy thin film was extremely stable after 60 days of exposure to methane (1000 PPB). Due to its high sensitivity, short reaction and recovery times, and stability, the sample thin film with 100 kGy irradiation can be used in gas sensor technology, particularly for the detection of methane gas at room temperature. The humidity sensing studies initiated by recording the variation of resistance, capacitance, response and recovery times were recorded. The humidity hysteresis loss and stability studies were carried out. A negligible loss in sensing response was noticed. [ABSTRACT FROM AUTHOR]

In this study, a joint theoretical and experimental approach was employed to investigate the structural, electronic, magnetic and dielectric properties of novel ferrite (CNF) Co1−xNixFe2O4 (x = 0.0, 0.25, 0.5, 0.75 and 1.0) nanoparticles obtained using a low-cost combustion synthesis technique. Structural analysis indicated the single-phase formation of synthesized ferrite with a cubic spinel structure. Rietveld refinement was performed to estimate the lattice constant, strain and cationic distances. Vibrational Raman spectroscopy was employed to further confirm the monophasic cubic spinel structure with inverse cation distribution associated with the increase of the T2g(2) Raman mode, evidencing the presence of different cations at octahedral sites. The real part of the dielectric constant (ε′) and the dielectric loss tangent (tan δ) were explored as a function of frequency, and the Nyquist complex impedance plots of all the samples were studied. The electrical properties of the samples at room temperature demonstrated the dispersion behavior associated with Maxwell–Wagner interfacial polarization mechanism and the hopping of charge carriers. DFT calculations complemented the experimental characterization, indicating a ferrimagnetic ground state for all models associated with band gap increases and dielectric constant reduction with an increasing amount of Ni. The low dielectric loss with Ni2+ substitution at higher frequencies makes CNF a promising candidate in the electronics industry for energy-harvesting devices. [ABSTRACT FROM AUTHOR]

Spinel Mn2+ Fe2−x3+Cex3+O4 (where x = 0.01–0.05) polycrystalline nanoparticles were fabricated by solution combustion method using glucose and urea as fuels. X-ray diffractogram (XRD) proved the witness of the cubic crystal consort of products which have the crystallite sizes in between 12 and 8 nm. The size of the sample was accomplished via transmission electron microscopy. The elemental composition of iron and manganese ions valences of MnCexFe2−xO4 samples were analyzed by X-ray photoelectron spectroscopy. XPS data reveals iron in all samples was trivalent; manganese was divalent, although tetravalent manganese ions were present on the surface of particles. Magnetic characterization of samples was done via Mössbauer spectroscopy at room temperature and at low temperatures (15 K). The Mössbauer analysis determines the consequence of Ce3+ substitution on isomer shift and quadrupole splitting of all samples. The low temperature Mössbauer spectroscopy results indicate that the presence of Ce3+ ions in the octahedron sites causes the decrease in the concentration of Fe3+ ions. [ABSTRACT FROM AUTHOR]

Nanoparticles of Co0.5Ni0.5Fe2−xCexO4 (where x = 0.0, 0.01, 0.015 and 0.02) ferrites are prepared by the modified solution combustion method using a mixture of fuels and are characterized to understand their structural, microstructural and magnetic properties. The X-ray diffraction is used to confirm the formation of a single-phase cubic spinel structure. The average crystallite sizes are calculated using the Scherrer formula and are found to be less than 50 nm. The microstructural features are obtained by the scanning electron microscopy, and the compositional analysis is done by using the energy-dispersive spectroscopy. The transmission electron microscopy (TEM) investigations show that the synthesized ferrites are made up of very fine spherical nanoparticles. The influence of a rare-earth element (Ce3+) on the magnetic properties of the samples was studied using the Mössbauer spectroscopy. The Mössbauer spectroscopy reveals the formation of broadened Zeeman lines and quadrupole-split lines and the presence of the Fe3+ charge state at B sites in the samples. The quadrupole splitting shows that the orientation of the magnetic hyperfine field with respect to the principle axes of the electric field gradient was random. The magnetic hyperfine field values indicate that the A sites have more A-O-B superexchange interactions than the B sites. The coexistence of magnetic sextet and a doublet component on the room-temperature spectra suggests superparamagnetic properties of the nanoparticles. The low-temperature (15 K) Mössbauer spectroscopy explores the paramagnetic relaxation in the nanoparticles. The area under the sextet refers to Fe3+ concentrations in the tetrahedral and octahedral sites of the ferrite. This study confirms that the Ce3+ substitution of Fe3+ only for octahedron sites causes the decrease in Fe-O-Fe arrangement. The effect of Ce3+ doping on the magnetic properties of Co0.5Ni0.5Fe2O4 is examined from the vibrating sample magnetometry (VSM) spectra. Saturation magnetization values are decreased initially and then increased, as result of Ce3+ doping. This can be explained by Neel's two-sub-lattice model. Further, the value of coercivity is found to be increasing with increasing Ce3+ concentration. The obtained results of M-H loop with improved coercivity (from 851 to 1039 Oe) by Ce3+ doping of Co0.5Ni0.5Fe2O4 demonstrate the usefulness for permanent magnet applications. [ABSTRACT FROM AUTHOR]

The article presents a case study of a seven-year-old male sloth weighing 90 kilograms which had mandibular fracture in India. Results of physical examination reveals that the sloth bear had epitaxis and lower jaw injury. Moreover, doctors prepared the sloth bear for surgery and given Ceftriaxone for seven days.

The article presents a case study of a day old female calf with evisceration due to the congenital failure of the umbilicus to close. The calf presented with hypothermia, moderate dehydration, and reduced heart and respiratory rates. Surgery was performed to return the hernia into the abdominal cavity. The surgical wound was sutured and the animal was treated with ceftriaxone post-operatively.