Polycrystalline Bi 0.8 Sr 0.2 Fe 1 À x Ti x O 3 (x ¼ 0.0, 0.1, 0.2) multiferroics were synthesized via the conventional solid state reaction method. The structure, dielectric relaxation, and magnetic properties of as prepared samples were investigated. The crystal structure examined via XRD and Rietveld analysis confirmed a single phase rhombohedral (space group R3c no. 161) structure. In the Rietveld refinement, good agreement between the observed and calculated pattern was observed. The dielectric response of these multiferroics was analyzed in the frequency range of 10 Hz to 5 MHz at different temperatures. All the samples showed dispersion in dielectric constant ( e) and dielectric loss factor (tan d) values. The temperature dependence of e and tan d showed broad peaks. A reduction in the values of e and tan d was observed upon the incorporation of Ti. Magnetic measurements were carried out at room temperature up to a field of 20 kOe. Magnetic hysteresis loops revealed a significant increase in magnetization with Ti substitution. A remnant magnetization (M r ) of 33.428 memu/g and a coercive field (H c ) of 1.724 kOe were observed in the sample with x ¼ 0.2.

Bi0.8Sr0.2Fe1−xNbxO3 (x = 0.0, 0.05, and 0.10) multiferroics were prepared by solid state reaction method. X-ray diffraction and Rietveld analysis show that crystal structure is rhombohedral for x = 0.0, 0.05 samples and triclinic for x = 0.10 sample. These samples showed dispersion in dielectric constant (έ) and dielectric loss (tan δ) values at lower frequencies. For x = 0.05 sample, both έ and tan δ are lower than for Bi0.8Sr0.2FeO3 sample indicating its high resistivity. For x = 0.10 sample, the value of έ is enhanced which may be due to formation of stronger dipoles in triclinic structure. Temperature dependence of frequency exponent “s” of power law suggests that correlated barrier hopping (CBH) model is applicable at lower temperatures and quantum mechanical tunneling model is appropriate at higher temperatures for describing the conduction mechanism in x = 0.0 and x = 0.05 samples; while in x = 0.10 sample, CBH model is appropriate in studied temperature range. Significant enhancement observed in magnetization for x = 0.10 sample is due to the structural phase transition from rhombohedral to triclinic caused by Nb substitution. For this sample, values of remnant magnetization (Mr) and coercive field (Hc) are 0.155 emu/g and 2.695 kOe, respectively.

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Introduction: Ankylosing spondylitis (AS) is an inflammatory rheumatic disease characterized by spine and sacroiliac joint involvement that mainly affects young male subjects. Bone Mineral Density (BMD) loss occurs in AS disease course. Bone loss in AS appears to be multifactorial and perhaps involves different mechanisms at different stages of disease. The disease typically affects young males and is associated with progressive functional impairment, increased work disability and decreased quality of life. Osteoporosis is frequent in AS and there is a close association of bone mineral density, bone metabolism and inflammatory activity. Osteoporosis is frequently associated with AS and BMD decreased predominantly in patients with active disease. Aims & Objectives:The aim of the present study was to study bone mineral density in cases of Ankylosing Spondylitis (AS) in comparison to age and sex matched controls. Material and Methods:The present study was conducted on 100 established cases of AS based on modified New York criteria and 150 controls healthy, age, race, socio-economic matched controls patients. The results were statistically analyzed.Results: Hundred cases of AS were subjected to undergo BMD by Dual Energy X-ray Absorption (DEXA) scan of different age groups in cases 35.19± 8.23(min age 23-max age 67years) and controls 33.27±5.22(min age 22years -max age 44years) with height observed in cases is 169.67±6-87 and controls 170.99±7.16 with weight varied in cases 65.63±10.27 and controls 70.14±10.67.

M-type hexaferrites with compositions BaFe12O19 (BFO), SrFe12O19 (SFO), Ba0.5Sr0.5Fe12O19 (BSFO), and Ba0.5Pb0.5Fe12O19 (BPFO) were synthesized by commercial solid state reaction method. The Rietveld refinement of x-ray powder diffraction revealed a single hexagonal phase with space group P63/mmc for BFO, SFO, and BSFO samples, whereas BPFO sample contains hematite (α-Fe2O3) phase with space group R3c along with the M-type main phase. All the samples show dispersion in dielectric constant (ɛ′) and dielectric loss (tan δ) values with frequency. The values of ɛ′ and tan δ increase with increase in temperature due to increase in the number of charge carriers and their mobilities, which are thermally activated. The reciprocal temperature dependence of conductivity (σac) and the most probable relaxation time (τM″) satisfies the Arrhenius relation. A perfect overlapping of the normalized plots of modulus isotherms on a single “super curve” for all the studied temperatures reveals a temperature independence of dynamic processes involved in conduction and for relaxation. Further, the complex plots of M* (M″ vs M′) indicate that dc conductivity dominates in the region below the M″max point. Above M″max, the variations follow Jonscher power law (σ = Aωs) implying that ac conductivity is dominating in this region. Among the prepared samples, SFO hexaferrite has lowest values of σac, ɛ′, and tan δ making it suitable for use in microwave devices.