Antibacterial and haematological activity of Moringa oleifera aqueous seed extract in Wistar albino rats

The phytochemical, antibacterial and haematologic activity of aqueous seed extract of Moringa oleifera (Moringaceae) were evaluated. Phytochemicals such as tannins, carbohydrates, alkaloids, cardiac  glycosides, anthraquinones and flavonoids in low, moderate and high concentrations were present in the seeds. The extract exhibited significant In vitro antibacterial and In vivo haematologic effects. Bacterial isolates such as Staphylococcus aureus, Streptococcus pyogenes, Bacillus subtilis, Corynebacterium pyogenes, Klebsiella pneumoniae, Salmonella typhi, Escherichia coli and Pseudomonas aeroginosa were inhibited. The  minimum inhibitory concentration of the extract for all the sensitive isolates is 100 mg/ml and 50 mg/ml as minimum bactericidal  concentration of the extract on Staphylococcus aureus, Salmonella typhi and Escherichia coli. The extract administered per os at 100-400 mg / kg body weight significantly (P<0.05) increased, neutrophil, eosinophil, basophil and monocytes counts at second and third week of administration except for lymphocyte that significantly (P<0.05) decreased throughout the period of administration when compared to the rats in control group. The study supports the folkloric application of Moringa oleifera seed extract in the management of various forms of bacterial infection, anaemia and immuno – modulation in north eastern Nigeria.Keywords: Antibacterial effect, Haematology, Moringa olifera, Phytochemical analysis, Wistar albino rats

Synthesis and Characterization of Cu–Mn Substituted SrFe12O19 Hexaferrites

In this study, bimetallic (Cu-Mn) substituted SrFe12O19 hexaferrites [Sr1-2xMnxCuxFe12O19 (0.0 <= x <= 0.1)] were synthesized via sol-gel auto-combustion approach. The effect of bimetallic substitution on structure, morphology and magnetism of SrFe12O19 was investigated. SEM images divulge the nano-size of the prepared products with speck morphology. X-ray powder diffraction analysis affirmed their complete conversion to SrFe12O19 hexagonal crystal phase. The results from Fe-57 Mossbauer suggested that all five important sextets of Sr1-2xMnxCuxFe12O19 hexaferrites effected due to the substitution of Cu and Mn ions. Cation distribution calculation showed that as the percentage of Mn and Cu increased in Sr1-2xMnxCuxFe12O19 (0.0 <= x <= 0.1), particularly for x = 0.03 the relative area of 12k and 4f(2) site increased. This indicates that Fe ions are migrated towards 12k and 4f(2) octahedral site

Synthesis and Structural and Magnetic Characterization of BaZn x Fe12−x O19 Hexaferrite: Hyperfine Interactions

To study the effect of Zn substitution on structural magnetic properties and hyperfine interactions of barium hexaferrite, BaFe12-x Zn (x) O-19 (0.0aexae0.3) hexaferrites were synthesized via sol-gel auto-combustion technique. Rietveld analysis of XRD powder patterns confirmed the formation of single-phase hexaferrites for all products. Due to the larger ionic size of Zn2+ as compared with Fe3+, while x increases, the lattice constant parameters increase to a small degree. Nanoplate morphology of the products is presented by SEM analyses. It was observed that both saturation magnetization and coercivity decrease in almost the same manner with zinc concentration for all substitutions. Cation distribution calculations showed that Zn2+ occupies 12k, 4 f (2), 4 f (1), and 2b sites and at the same time pushes Fe3+ ions towards 2a and 12 k (1) sites. From(57)Fe Mossbauer spectroscopy data, the variation in line width, isomer shift, quadrupole splitting, and hyperfine magnetic field values on Zn2+ substitution have been determined

Electrical and Dielectric Properties of Y3+-Substituted Barium Hexaferrites

In this study, Y3+ ion-substituted M-type barium hexaferrites (BaM; BaFe12O19) were fabricated via facile ceramic route. As-prepared powders were characterized by X-ray powder diffractometry (XRD), Fourier transform infrared (FT-IR) spectroscopy, and impedance spectroscopy. XRD (Rietveld) analyses confirmed the presence of a single characterization of all samples (except x = 0.0 and 0.1 samples). The crystallite sizes of products are found in the range of 47.2-63.2 nm. Spectral analysis (FT-IR) also presented the formation of spinel structure for all products. The ac conductivity of the substituted samples was found to initially decrease slightly with increase in Y3+ compared with unsubstituted, and then variation tendency changes at the medium substitution ranges are observed with a different attitude against temperature. In the end, the lower conductivity for high substitutions is recorded and increases as functions of frequency while it also increases with the elevation of temperature. It was observed that ac conductivities of products increased by increasing frequency which indicate that observed ac conductivity is due to both electronic and polaron hopping mechanism

Impact of Tm³⁺ and Tb³⁺ rare earth cations substitution on the structure and magnetic parameters of Co-Ni nanospinel ferrite

Tm-Tb co-substituted Co-Ni nanospinel ferrites (NSFs) as (Co0.5Ni0.5) [TmxTbxFe2−2x]O4 (x = 0.00–0.05) NSFs were attained via the ultrasound irradiation technique. The phase identification and morphologies of the NSFs were explored using X-rays diffraction (XRD), selected area electron diffraction (SAED), and transmission and scanning electronic microscopes (TEM and SEM). The magnetization measurements against the applied magnetic field (M-H) were made at 300 and 10 K with a vibrating sample magnetometer (VSM). The various prepared nanoparticles revealed a ferrimagnetic character at both 300 and 10 K. The saturation magnetization (Ms), the remanence (Mr), and magneton number (nB) were found to decrease upon the Tb-Tm substitution effect. On the other hand, the coercivity (Hc) was found to diminish with increasing x up to 0.03 and then begins to increase with further rising Tb-Tm content. The Hc values are in the range of 346.7–441.7 Oe at 300 K to 4044.4–5378.7 Oe at 10 K. The variations in magnetic parameters were described based on redistribution of cations, crystallites and/or grains size, canting effects, surface spins effects, super-exchange interaction strength, etc. The observed magnetic results indicated that the synthesized (Co0.5Ni0.5)[TmxTbxFe2−x]O4 NSFs could be considered as promising candidates to be used for room temperature magnetic applications and magnetic recording media

Electrical and Dielectric Characterization of Bi–La Ion-Substituted Barium Hexaferrites

BaLa (x) Bi (x) Fe12-2xO19 (0.0 ae x ae 0.5) hexaferrites were produced by solid-state synthesis route, and the effect of Bi3+ and La3+ substitutions on electrical and dielectric properties of barium hexaferrite material were investigated. It is noticed that ac conductivity of barium (BaM) increases slightly with ionic substitutions of both La3+ and Bi3+ and then decreases. Ac conductivity is increased with increasing frequency at lower temperatures then remains constant for higher temperatures. This type of conductivity attitude could be originated from the indication of both electronics and polaron hopping mechanisms. The dielectric properties of BaLa (x) Bi (x) Fe12-2xO19 (0.0 ae x ae 0.5) hexaferrites represent a very interesting tunability as functions of frequency, temperature, and Bi3+ and La3+ ions