Albumen-mediated Green Synthesis of ZnFe2O4 Nanoparticles and Their Physico-Chemical Properties

Spinel ferrites with general formula AB2O4 possess charming magnetic and electrical properties owing to their thermal and chemical steadfastness. Spinel zinc ferrite (ZnFe2O4) nanoparticles have attracted massive attention due to their unusual amalgamation of properties, especially magnetic properties, where these properties are equipped as suitable candidates in the field of electronics. Here, a simple self-combustion technique is made with the assistance of albumen to synthesize nanocrystalline zinc ferrite (ZnFe2O4) particles. The egg white (albumen) that is used in the synthesis process plays the fuel role in the process of combustion. The results of the powder X-ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FTIR) suggested that the synthesized nanoparticles are of single phase and show spinel structure. The photoluminescence studies reported a doublet peak at around 360-380 nm. The functional groups present in the synthesized nanoparticles were revealed from FTIR data. EDX findings give an account of the percentage composition of the elements Fe, Zn and O present in the synthesized sample. High-resolution Scanning Microscope (HRSEM) reveals the agglomerated coalescence nature of ferrite nanoparticles. Keywords: Ferrite, PXRD, FTIR, HRSEM, EDX Albumen.

Structural and Optical Properties of Pure NiO Nanoparticles and NiO-Mn2O3, NiO-CdO, NiO-Pb2O3, NiO-ZnO Nanocomposites

Pure nickel oxide (NiO) nanoparticles and NiO-Mn2O3, NiO-CdO, NiO-Pb2O3, NiO –ZnO nanocomposites were synthesized by co-precipitation method. The PXRD studies revealed that NiO, Mn2O3 and CdO possessed cubic structure, Pb2O3 possessed monoclinic structure, ZnO possessed hexagonal structure and confirmed the presence of polycrystallinity nature of NiO and Mn2O3, CdO, Pb2O3, ZnO in the nanocomposites. The average grain size of NiO nanoparticles was found to be 30.10 nm using Debye Scherer’s formula. The FESEM images of NiO nanoparticles and their nanocomposites revealed spherical shaped structure and NiO-Pb2O3 revealed needle shaped rod-like structure. EDAX analysis confirmed the composition of NiO nanoparticles and their nanocomposites. Raman spectra exhibited characteristic peaks of pure NiO and that of NiO- Mn2O3, NiO-CdO, NiO- Pb2O3, NiO-ZnO in the synthesized nanocomposites. In the PL spectra, blue and green emission was observed in the samples. UV-vis spectra revealed the absorption peaks of NiO nanoparticles and their nanocomposites. Thus, the synthesized NiO- Mn2O3, NiO-CdO, NiO - Pb2O3 and NiO-ZnO nanocomposites can be a suitable material for electrocatalysis applications. Keywords: Nickel oxide nanocomposites, Structure, Morphology, Absorption, Luminescence.

Structural and Surface Characteristics of CuO and Pt/CuO Nanostructured Thin Films

The most prominent and utilizable platinum-coated copper Oxide nanostructured thin films are prepared using the SILAR method. Their structural properties have been studied using X-ray diffraction (XRD) and Raman spectroscopy. XRD pattern reveals the phase purity and crystallinity of CuO nanostructures. The average grain size estimated from XRD gives diameters in the range of 14 - 27 nm. Raman spectra explain the structural information of CuO and Pt/CuO nanostructured thin films, in which the peaks observed at 328 cm-1, 609.32 cm-1 and 1141.77 cm-1 are the different phonon modes of CuO. The peak at 2136 cm-1 provides strong evidence for the formation of platinum on CuO nanostructures. The SEM micrograph confirms the floral morphology, which is composed of nano petals. From the observed morphology, it is observed that the deposited thin films such as CuO and Pt/CuO will give interesting applications to our society by being self-cleaning agents, photocatalysts, semiconductor devices, optical fibers, … etc. Keywords: CuO, Pt/CuO, Structural analysis, SILAR, Crystallinity.

Effect of ZrO2 Nanofiller on the Physical Properties of Epoxy Composites: Mechanical, Thermal and Dielectric

In this present work, Zirconia nanoparticles were prepared by precipitation method, Zirconium Oxychloride (ZrOCl2.8H2O) and ammonia (NH3) as starting materials. The synthesized Zirconia nanoparticles were characterized by XRD and the grain size in nanoscale was confirmed. The sheets of neat epoxy resin and epoxy with addition of ZrO2 nanoparticles are primed by solution casting method. The structures of epoxy polymer and hardener were found out using FTIR analysis. The thermal properties were analyzed using Thermo Gravimetric Analysis (TGA) and Differential Thermal Analysis (DTA). Thermo gravimetric analysis has been employed to investigate the thermal characteristics and their mode of thermal degradation. Differential thermal analysis has been used to determine the glass transition temperature of epoxy nanocomposites. The mechanical properties like tensile and flexural studies were analyzed and thus influences of nanofiller loading on these parameters were found to be very low. Keywords: Epoxy, ZrO2 nanoparticles, Nanocomposites, Thermal stability, Dielectric properties, Tensile strength, Flexural strength.

Synthesis and Characterization of Zn-doped CuWO4Nanoparticles and Their Opto-structural Properties

CuWO4 and Zn-doped CuWO4 nanoparticles were prepared by a solid-state reaction method. The XRD study confirms the triclinic crystal structure for both samples and the peak shift is noticed for Zn-doped CuWO4 particles with high crystallinity. The FTIR spectra show metal oxide vibration which arose from the CuWO4 and Zn-doped CuWO4 particles. The optical absorption spectra exhibit strong absorption in the visible region and the band gap of Zn-doped CuWO4 is found to be increased to 2.44 eV compared to that of CuWO4 (2.36 eV), which is due to the elevated conduction band levels after Zn-doping. The SEM images of both CuWO4 and Zn-doped CuWO4 nanoparticles show densely aggregated particles. Keywords: Copper tungstate, Zn-doped CuWO4, Absorption, Nanoparticles.

Albumen-assisted Synthesis of Nanocrystalline Nickel Ferrite Photocatalyst

As a simple step to remove the polluting dyes in aqua ecosystem, NiFe2O4 nanoparticles well known for their ferromagnetic properties, low conductivity and high electrochemical stability were prepared by simple auto combustion method using egg white as fuel via green synthesis route. The structural, morphological and magnetic properties of prepared NiFe2O4 was analyzed. The desirable phase purity of the prepared spinel ferrite was deliberated by X-ray Diffractometer (XRD), Fourier Transform Infrared Spectrometer (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive and Vibrating Sample Magnetometer (VSM). XRD predicts the phase formation, particle size and lattice parameter of the spinel ferrite. The FTIR spectrum confirms the ferrite structure. The morphological and elemental analysis was made using SEM and EDAX. The hysteresis curve reveals the magnetic properties, such as remanence magnetization (Mr), coercivity (Hc) and saturation magnetization (Ms). The photocatalytic efficiency of the synthesized samples was determined from degradation of methylene blue dye. The whole process was monitored using spectrophotometer at regular intervals of time. The maximum photocatalytic degradation efficiency for NiFe2O4 is around 95.6 %. Keywords: NiFe2O4, Ferrite, Green synthesis, Egg white, Combustion, Photocatalyst.

The Electromagnetic Field outside the Steadily Rotating Relativistic Uniform System

Using the method of retarded potentials, approximate formulae are obtained that describe the electromagnetic field outside the relativistic uniform system in the form of a charged sphere rotating at a constant speed. For the near, middle and far zones, the corresponding expressions are found for the scalar and vector potentials, as well as for the electric and magnetic fields. Then, these expressions are assessed for correspondence to the Laplace equations for potentials and fields. One of the purposes is to test the truth of the assumption that the scalar potential and the electric field depend neither on the value of the angular velocity of rotation of the sphere nor on the direction to the point where the field is measured. However, calculations show that potentials and fields increase as the observation point gets closer to the sphere’s equator and to the sphere’s surface, compared with the case for a stationary sphere. In this case, additions are proportional to the square of the angular velocity of rotation and the square of the sphere’s radius and inversely proportional to the square of the speed of light. The largest found relative increase in potentials and fields could reach the value of 4% for the rapidly rotating neutron star PSR J1614-2230, if the star were charged. For a proton, a similar increase in fields on its surface near the equator reaches 54%. Keywords: Electromagnetic field, Relativistic uniform system, Rotation.

The Alpha Particle Doses Received by Students and Staff in Twenty Schools in the North of Hebron Region - Palestine

The aim of the current study was to measure indoor radon concentration levels and its resulting doses received by the students and staff in schools of the directorate of education in the north of Hebron region- Palestine, during the summer months from June to September (2018), using CR-39 detectors. In this study, a total of 567 CR-39-based radon detectors were installed in the selected schools. The average radon concentrations were found to be 90.0, 66.5 and 58.0 Bqm-3 in Halhul, Beit Umar and Alarrub camp schools, respectively. Based on the measured indoor radon data, the overall average effective dose for the studied area was found to be 0.31 mSvy-1. Reported values for radon concentrations and corresponding doses are lower than ICRP recommended limits for workplaces. The results show no significant radiological risk for the pupils and staff in the schools under investigation. Consequently, the health hazards related to radiation are expected to be negligible. Keywords: Radon concentration, Alpha particles, Annual effective dose, Schools. PACs: 29.40.−n.

Investigation of the Structural and Magnetic Properties of BaM Hexaferrites Prepared from Scrap Iron Filings

In this work, we demonstrate the feasibility of preparing a commercially important type of magnetic oxide, BaM (BaFe12O19) hexaferrite, using scrap iron filings as an iron source. The hexaferrites were prepared by conventional solid state reaction and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and magnetization measurements. XRD patterns of samples prepared by mixing powders extracted from the iron filings with appropriate amounts of barium carbonate and sintering at 1200 °C revealed the presence of a major BaM hexaferrite with small amounts of nonmagnetic α-Fe2O3 oxide phase. On the other hand, SEM images of the samples showed clear crystallization of perfect hexagonal platelets of BaM hexaferrite, which was further confirmed by the Curie temperature determined from the thermomagnetic measurements. The saturation magnetization of the samples was in the range of 45.1– 52.1 emu/g and the remnant magnetization in the range of 14.8 – 19.0 emu/g. These values and the moderate coercivity of ~ 1 kOe suggest that the prepared samples could potentially be useful for high-density magnetic recording. Keywords: Hexaferrite, Solid waste, Magnetic Properties, Structural properties, Magnetic recording.

Applying in-Situ and Laboratory-based Gamma Spectrometry to Determine Activity Concentration and Distribution of 40K, 226Ra and 232Th in Abeokuta, Southwest Nigeria

The applications of radionuclides are potential sources of health risk and also a concern in the area of nuclear security. It is therefore imperative to determine the presence of the different radionuclides present in the environment at all times, because it is necessary to control and assess the risk level in the environment. The present study compares activity concentrations of the primordial radionuclides 40K, 226Ra and 232Th obtained from laboratory gamma spectrometry measurements with the activity concentrations of the radionuclides as obtained from in-situ measurements. Soil samples were randomly collected from nineteen different points within Abeokuta city ensuring good coverage of the city area. A mobile gamma spectrometry system was used to collect gamma spectra measurements in the field. The obtained values are presented. The ranges of activity concentrations for 40K, 226Ra and 232Th have been found to be 113 – 1975, 5 – 128 and 181 – 3284 Bqkg-1, respectively for laboratory gamma spectrometry and 104 – 1312, 31 – 121 and 104 – 2578 Bqkg-1, respectively for in-situ gamma spectrometry measurements. This study showed that the average activity concentrations of the primordial radionuclides in Abeokuta were much higher than worldwide averages of 400, 35 and 30 Bqkg-1 for 40K, 226Ra and 232Th, respectively. From both methods, 232Th is seen to be the major contributor to the environmental radioactivity of Abeokuta. Good correlations also were deduced between the activity concentration results obtained from laboratory and in-situ gamma spectrometry, which therefore implies a significant relationship between the two methods used in the study. Keywords: In-situ gamma, Gamma spectrometry, Activity concentration, Radionuclides.