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Barium Strontium Titanate (BaSrTiO3) film which was captured by carbon dot with variation container 0%, 2%, 4%, 6% using CSD method with the help of spin coating with a rotating speed of 8000 rpm has been successfully made on p-type silicon substrate 100. The film was annealed at 850 °C and held for 8 hours. Barium Strontium Titanate (BaSrTiO3) film at a concentration 0%, 2%, 4%, 6% carbon dot characterized by UV-VIS, XRD, SEM-EDX to produce bandgap energy in sequence 2.72 eV; 2.85 eV; 3.7 eV and 3.8 eV. The result of XRD characterization showed that the BST lattice structure is a cube with lattice parameters a=b=c in sequence of 4.066945 Å; 4.06868 Å; 4.072155 Å and 4.077379 Å. The result of SEM-EDX characterization showed that in the surface morphology of BST film the grain size was quite homogeneous and the corresponding atomic compositions obtained were Ba, Sr, Ti, O, and C [ABSTRACT FROM AUTHOR]

Studies of metal content (Cd, Cr, Cu, Mn, Pb, Ca, and Sr) in well water and abnormal teeth have been carried out using AAS and XRF methods. The purpose of this study was to determine the causes of tooth abnormalities and gingival discoloration in residents of the Kualin and Kolbano Districts. The experiment included a sampling of well water which is usually consumed and abnormal teeth which were carried out randomly, then the well water was analyzed for elemental content of Cd: 0.01 mg/L, Cr: 0 0.05 mg/L, Cu: 0.1 mg/L, Mn: 0.05 mg/L, and Pb: 0.01 mg/L by AAS method, on abnormal tooth samples, and well water were analyzed using XRF method. The elements of Cd, Cr, Cu, Mn, and Pb in well water were not detected. With the XRF method, it was found that abnormal teeth contained calcium in a concentration of (4.232 – 51.352) % which was not much different from normal teeth. The results showed that the cause of the discoloration of the abnormal tooth and gingival was only to the high concentration of strontium metal in abnormal teeth, namely (368.543 – 1736.674) ppm which probably came from well water containing strontium (9.231-31.368) mg/L which far exceeds the drinking water standard (Sr = 2 mg/L). [ABSTRACT FROM AUTHOR]

A fascinating inspection on Zn2+ substituted Strontium Hexaferrite having nominal composition SrFe12-xZnxO19 (x = 0, 0.2) is carried out by solid state reaction method. X-Ray Diffraction characterization is implemented to analyze the structural features of the manufactured samples. Phase purity and crystallinity of the synthesized compositions are authenticated by rietveld refinement method. The parent in addition with substituted sample belong to P63/mmc space group. Dielectric properties of the prepared sample are exclusively scrutinized from 30 °C to 400 °C in the variation of frequency ranging from 100 Hz to 1 MHz. The variation obtained from frequency dependent plots discovers that dielectric constant along with loss tangent are in well accordance with Maxwell-Wagner and Koop's phenomenological model. Hysteresis curves obtained from isothermal field dependent magnetization show the ferrimagnetic nature of the sample. However, saturation magnetization increases and coercivity decreases with substitution as compared to parent sample. [ABSTRACT FROM AUTHOR]

The structure and dielectric properties of 6% Sr2+-substituted, modified Lead Zirconium Titanate (PZT) piezoelectric ceramic, with composition [Pb0.94Sr0.06][(Mn1/3Sb2/3)0.05(Zr0.54Ti0.46)0.95]O3 and lead manganese antimonite as an additional dopant, synthesized by ceramic route have been investigated in a frequency range from 50Hz to 1MHz and in a temperature range between room temperature and 633K. The scaling behavior of imaginary part of the electric modulus suggests that the relaxation is described by the same mechanism at various temperatures. [ABSTRACT FROM AUTHOR]

Crystal structure and impedance spectroscopy investigation of Lanthanum modified Bi0.35-xNa0.35Sr0.3LaxZr0.1Ti0.9O3 (BNSZT) electro-ceramics are reported. La modified BNSZT composites are synthesized by solid state mixed oxide technique using their constituent carbonate and oxides; the wet mixed oxides were calcined at 1000°C for 12hrs. X-ray diffraction characterization are carried out on the calcined powder to confirm the crystal structure and the variation of lattice parameters, volume of the unit cell, average crystallite size and de-gree of tetragonality as a function of La modification. Impedance spectroscopy investigation are reported on the pure and 8% modified BNSZT at room temperature. [ABSTRACT FROM AUTHOR]

Experimental results on the effect of heating with simultaneous take-off thermionic current on the stability of thermionic emission in composite cathode materials Ba0.25Sr0.75HfO3 with 16% W (by mass) are presented. It is found that cavities with a total absence of barium-strontium hafnate appear inside the samples after 5-hour heating. Due to a decrease in the diffusion flux of Ba and Sr to the emitting surface, the emission activity of the composites drops sharply. The reasons for such cavities formation are clarified: overheating of internal regions of the material by the take-off thermionic current to temperatures comparable to the melting temperatures of the composite individual components, as well as the accelerated diffusion of Ba and Sr in the presence of a large temperature gradient equal to 4.3×106 K/m. The calculated diffusion coefficient of Ba and Sr, equal to 2×10−12 m2/s, exceeds the self-diffusion coefficient of Ba in BaO by two orders of magnitude. [ABSTRACT FROM AUTHOR]

The coals from the Raichikhinskoe (North-Eastern open pit) and Yerkovetskoe (Yerkovetsky open pit) coal deposits in the Amur Oblast were studied. Based on the results of analytical studies, the content of rare metals, including trace and precious metals in coals and rock interlayers was estimated. The concentration of some rare elements in lignite was found to be higher than the Clarke content. The content of strontium and the sum of REE+Y+Sc in lignite ash of the North-Eastern open pit of the Raichikhinsky deposit were at the level of the minimum commercial content. Increased concentrations of lithophile elements in the coals of the studied deposits and the features of the geological structure of the area suggest their accumulation in the coals as a result of the run off mainly from the acidic (granite) flanks of the Zeya-Bureya Basin. [ABSTRACT FROM AUTHOR]

A new semi-organic compound named Strontium Boro Tartrate (SBT) was synthesized by hydrothermal method. UV-Visible and FTIR analysis were carried out to analyze its transparency range and functional groups in this crystal. Thermal analysis of TGA/DSC were done to identify its thermal stability and decomposed products. Dielectric studies have been done to analyze its electro-optic property. Frequency doubling property was analyzed by NLO test. [ABSTRACT FROM AUTHOR]

Al-Si cast alloys can be used for making intricate castings and thin as well as thick-wall castings. Apart from strength and corrosion resistance, tribological characteristics are also very important for automobile and aerospace application requirements. So, it is important to have an understanding of the mechanism of tribological behavior of these alloys. The effect of strontium modification on the wear behavior is studied for different Al-Si cast alloys (with 5,7,10,12, and 17 wt.% Si content) using two tribo-pairs. The wear test of Al-Si cast alloys was carried out using a pin-on-disc apparatus with two counter Disc (SS304 and EN31) under the same velocity, sliding distance, and at a constant load for comparison purposes. The hardness of the modified alloys has been observed to increase 5-11 % compared to unmodified alloys and a 70.4 % increase from unmodified Al-5Si (Hypoeutectic alloy) to modified Al-17Si (hyper eutectic alloy). The secondary dendrite arm spacing (SDAS) and eutectic silicon particle size of modified alloys were found to be lower than the corresponding unmodified alloys. The maximum wear rate was observed in unmodified Al-5Si (hypo eutectic alloy) and SS304 Tribo-pair and the best wear resistance was found in modified Al-17Si and EN31 Tribo-pair. The SEM analysis shows a combination of adhesive, abrasive, and delamination wear in hypoeutectic Al-Si alloy on SS304 and Oxidation wear was found predominantly along with abrasive wear track in modified hyper eutectic Al-Si alloy on EN31. [ABSTRACT FROM AUTHOR]

In this paper, the Tl1-xHgxSr2Ca2Cu3O8+δ compound with X=(0.0, 0.1, 0.2, 0.3 and 0.4) was prepared by using the method of solid-state. The electrical resistivity was studied using the four probes technique to find the transition temperature at zero resistance Tc(off) and at translation Tc(on). Tc (off) and Tc (on) increased from 103 to 133 K and 112 to 135 K with an increase in mercury concentration from 0 to 0.4, respectively. The sample crystal structure was studied using an X-ray diffraction device. The X-ray diffraction (XRD) study of the crystalline nature confirmed that the sample of the compound has a lattice structure of a mixture of different phases, it has a tetragonal. The traditional Debye-Scherrer method and the methods modified for it were calculated and investigated from the crystal size. It is noted the approximate values of crystal size and crystallinity in percentage between the two modified Scherer methods and the traditional Scherer method change depending on the intensity picks of the XRD diagram. Furthermore, the sample was taken into account to determine the physical and microstructure factors such as strain. [ABSTRACT FROM AUTHOR]

The depletion of mineral resources on land is a problem due to the increasing demand for strontium in industry. It shows a need to explore strontium (Sr2+) resources by extracting Sr2+ in seawater. We used a fulvic acid (FA) isolated from compost to coat Fe3O4/MnO2 nanocomposite due to the low production cost. The compost was collected from the Supit Urang TPST, Malang City, East Java, Indonesia. Synthesis of Fe3O4/MnO2/FA nanocomposite was performed using the sonochemical co-precipitation method. The characterization results showed that FA, Fe3O4 nanoparticles, and Fe3O4/MnO2/FA nanocomposites were successfully isolated and synthesized. The application of synthesized nanocomposites for Sr2+ adsorption showed that the Sr2+ adsorption efficiency in the standard solution and seawater samples at 99.60% and 41.24%, respectively. [ABSTRACT FROM AUTHOR]

By using the half life time for strontium (78-100Sr) and (Germanium 66-76Ge) isotopes for even-even from Ferston we calculated the electric quadruple transition and find the relation between number of neutron and |M(E2)|2W.u ↓ for gamma ray from 2+ to 0+. When calculating the theoretical value of the energy state (first and ground) and the current work of the transition probability (T) and the mean life time (τ (s)) of an isotope of strontium, The theoretical value of the energy state (first and ground) and the current action of the transmission force |M(E2)|2W.u ↓ by calculating the theoretical value of the total width for gamma decay and calculating the Weisskopf Γ(E2)w.u energy (the Weisskopf single -particle widths), which is included in the equation where depend on Eγ calculated in keV and A is the mass number. The results were tabulated, discussed and drawn, as it was found that the value of |M(E2)|2W.u ↓ is the lowest possible at the magic number of neutrons is equal 50, and the values increase as we move away from the magic numbers, that is, when the nuclei are saturated, regardless of the number of protons, which play an important role for the same subject and for even-even nuclei. [ABSTRACT FROM AUTHOR]

This study is aimed to define the dependence of the mechanical properties of ferrogel (FG), chosen as a prospective scaffold for cellular technologies, on the concentration of magnetic particles (MPs) embedded into composite. FGs based on polyacrylamide hydrogel filled with the strontium hexaferrite (SrFe12O19) MPs with weight fraction in the range of 0 – 11 % were investigated with the use of two independent approaches: stress-strain testing of mechanical deformations in step-wise and dynamic modes and by medical ultrasound imaging. Stress-strain test showed that the increase of MPs concentration in FG resulted in significant increase of elastic storage modulus (G'), loss modulus (G") and dynamic viscosity coefficient (η') of the magnetic composite. According to the ultrasonography test, the increase of MPs concentration in FG provided the enhancement of FG visualization. The larger was the MPs concentration in FG, the higher was brightness of the ultrasound image at the surface of FG and inside its bulk. Close correlation was found between the elastic storage modulus (G') and the brightness at water/FG interface for full range of MPs concentrations. [ABSTRACT FROM AUTHOR]

A comparison of the physicochemical properties of T-3 and T-3K "Termoxid" sorbents, as well as the possibility of sorption of Cs-137 and Sr-90 radionuclides from low-mineralized waters, has been carried out. Composition, structure, porosity of sorbents have been investigated. It has been shown that the T-3K sorbent can be used for the selective concentration of 90Sr from low-mineralized waters with the combined presence of 137Cs and 90Sr. The distribution coefficient of strontium is (1.3 ± 0.6) · 104 ml/g, the static exchange capacity is 49 ± 12 mg/g. Sorption of 137Cs does not occur. [ABSTRACT FROM AUTHOR]

Sorption of Sr-90 by the inorganic sorbent Thermoxide-3K from tap water and CaCl2 and NaCl solutions under static conditions was studied. It was shown that in the presence of calcium in the aqueous solution, the sorption of strontium decreases. At calcium concentrations greater than 50 mg/L, the value of the strontium distribution coefficient remains constant lg Kd (Sr) = 4.2±0.2 ml/g and the strontium-calcium separation factor is 2.0. The strontium sorption decreases with an increase in the sodium concentration in the solution to 0.0001 mol/L. The isotherm of strontium sorption from tap water over the entire concentration range under consideration has the form of the Langmuir isotherm. The static exchange capacity of the sorbent is 30 mg/g. The sorbent can be used to concentrate strontium from natural waters of various mineralization and liquid radioactive waste. [ABSTRACT FROM AUTHOR]

Reaction of sodium orthophosphate, Na3PO4, with NaCl–KCl–LaCl3–BaCl2, NaCl–KCl–LaCl3–SrCl2, NaCl– KCl–GdCl3–BaCl2, NaCl–KCl–CsCl–LaCl3–BaCl2 and LiCl–KCl–LaCl3–BaCl2 melts was studied at 1023 and 823 K. Phosphates formed under various conditions were characterized by X-ray powder diffraction. Particle size distribution curves of precipitated phosphates were measured. [ABSTRACT FROM AUTHOR]

This work intends to improve peak current; multi walled carbon nano tube (MWCNT) and nano aluminium blended EDM of Nimonic 90 utilizing a multi-response optimization Grey Relational Analysis (GRA) approach rather than a single response optimization. A thorough investigation revealed that different combinations of EDM input parameters are necessary to provide a improved material MRR, lower TWR and SR for Nimonic 90 Nickel super alloy. Taguchi approach is used in this work to develop single objective optimization and optimum factor configurations for multi- objective output response optimization. Grey relational technique is used to investigate MRR, SR, and TWR simultaneously. The results showed that utilizing this method significantly enhanced machining performance. The confirmation tests were carried out at the ideal parameter set, and it was revealed that the predicted values of responses at the ideal combination of parameters are in excellent agreement with the confirmation research findings. [ABSTRACT FROM AUTHOR]

The influence of the zinc (Zn), strontium (Sr) and silicon (Si) incorporation in the structure of calcium phosphate (CaP) coatings during the micro-arc oxidation (MAO) under the different applied voltages (200–350 V) was studied. It was showed that CaP without additives, Sr-Si-containing CaP (Sr-Si-CaP) and Zn-Si-containing CaP (Zn-Si-CaP) coatings deposited at a low MAO voltage of 200 V were predominantly in the X-ray amorphous state. Increasing the applied voltage up to 350 V led to the formation of amorphous-crystalline structure in all types of the coatings. It was concluded that the amount of CaHPO4 crystalline phase in the coatings increased in the following order: Sr-Si-CaP (64 vol %) < Zn-Si-CaP (73 vol %) < CaP (80 vol %). Moreover, a gradient phase structure from an amorphous to an amorphous-crystalline state was observed along the thickness of all the coatings formed at MAO voltages of more than 250 V. [ABSTRACT FROM AUTHOR]

A fine material of natural clinoptilolite was used in order to study the performance on strontium removal. To study the saline effect based on learning from Fukushima accident, the effect of seawater to the nuclear effluent system is interested to be studied. The intrusion of seawater to the strontium waste treatment could affect the quality of the treatment process, especially in ion exchange techniques. Ion exchanges technique was conducted on the stable isotope of strontium. The saline water was applied for ion exchange process. A Varian 240 fs Atomic Absorption Spectrophotometer (AAS) machine was used to measuring the concentration in the liquid phase. The reduction of strontium ion in ion exchange process was found to be dramatically decreasing after contact with saline water due to the competition with potassium ion from saline water. [ABSTRACT FROM AUTHOR]

The extraction of strontium (Sr2+) from seawater has been of concern to many researchers. Sr2+ extraction is one solution to secure Sr2+ resources to meet current and future industry demands. In this research, we used the Sr2+ extraction method from seawater of the South Coast, Gulf Prigi using Fe3O4/MnO2/humic acid (HA) nanocomposites. The examining regeneration and reusability of the three cycles showed an adsorption efficiency of 99%. The adsorption efficiency in the first cycle was 95.13% and decreased in the next cycle. In seawater samples, our nanocomposites showed Sr2+ extraction efficiency of 50.54% from their initial concentration of 6.43 mg/L at pH 6.8. At pH 10, nanocomposites showed an extraction efficiency rate of 62.52%. Coating Fe3O4/MnO2 nanocomposite with HA can be an alternative adsorbent for the extraction of Sr2+ from seawater. [ABSTRACT FROM AUTHOR]

In this paper, the sample La1-xSrxMn0.4Ti0.6O3 (x = 0.32, 0.34 and 0.38) has been fabricated using solid-state reaction method and its structural and electrical properties have been studied. The X-ray diffraction patterns reveal that the sample's structure was attributed to the cubic structure ("a" = 3.8968 Å) with space group Pm-3m and a volume of 59.17 Å3. The surface morphology shows the sample's grain and grain boundaries are well formed. As the strontium doping increase, merging between grains occurred. The electrical properties of the samples analyzed using the Cole-Cole Impedance possesses one semi-circle due to grain effect. A model using an electrical circuit has been purposed. The values of capacitance obtained are approximately 2 x10-10 F to 6 x10−10 F. [ABSTRACT FROM AUTHOR]

Precipitation of strontium phosphates from LiCl–KCl–SrCl2 at 550 °C, and NaCl–KCl–SrCl2 and NaCl–KCl– CsCl–SrCl2 melts at 750 °C was investigated. Sodium phosphate was employed as the source of phosphate ions. The experiments were carried out under static conditions in an inert atmosphere. X-ray powder diffraction analysis was employed for identifying the compounds formed and particle size distribution curves were measured. [ABSTRACT FROM AUTHOR]

A molecular dynamics simulation of helium diffusion in solid CaF2, SrF2, and BaF2 was carried out using the empirical pair potentials reproducing the experimental strong binding of helium to cations in these crystals. The model diffusion coefficients and activation energies are determined. [ABSTRACT FROM AUTHOR]

The chemical composition of the bottom sediments of Bering Sea (northwest of the Pacific) was measured by method of X-ray fluorescence analysis using synchrotron radiation (SRXRF) at the collective station, VEPP 3 (Institute of Nuclear Physics, SB RAS). Column length is 560 cm. The study of the chemical composition of this column is a continuation of large-scale work aimed at studying the climate of the North Pacific. The aim of the work is to construct several climate change schemes for the Bering Sea and the subarctic of the Pacific for the characteristic time slices of the last two glacier-ice cycles: the maximum of the last glaciation, the Marine Isotope Stage 4 (MIS 4), the maximum of the last interglacial glaciation (MIS 5.5), the maximum of the penultimate glaciation (Heinrich event 11, MIS 6.2) and the warmest possible MIS 6.5. The general characteristic patterns of orbital and millennial environmental, climate and ventilation changes in the Bering Sea and the Pacific subarctic that have occurred during global climate change over the last two glaciation-ice cycles (190-0 thousand years ago) will be established. Analysis of mutual influence of environment and climate parameters between the subarctic of the Pacific Ocean and the Bering Sea over the last 190 thousand years. The experiment is aimed at studying the distribution of chemical elements, markers of paleoclimatic changes along the core of bottom sediments in order to identify orbital and rapid climate changes in the last two cycles of glaciation-icing. And also to clarify the role of the region in changes in the palaeoceanology of the world's oceans and in the interaction of water and atmosphere that had occurred during orbital and millennial climate changes. As part of the work were obtained distributions of chemical elements (from K to Mo for K-series and U, Th, Pb for L-series) along the column under study in 1 cm steps. The conducted cluster analysis showed the presence of two large groups of elements. The first one reflects the terrigenous component of the sediment (K, Rb, Nb, Th, Y, Zr, Mo, Ti, Fe, etc.) and the second - biogenic (Ca, Sr, U, Ge, As, Br). In the Fourier and wavelet spectra of the distribution of the chemical elements were found periodically components comparable with periods of D-O events. [ABSTRACT FROM AUTHOR]

The growth of Ba1-xSrxTiO3 ferroelectric film has been successfully doped using mole variations of Sr-doped with the percentage of 1%, 3%, 5%, and 10%. Variations were made to determine the effect of Sr-doped mole concentrations on the microstructure, optical properties, and electrical properties of the coating applied to the photovoltaic effect. The deposition of the film was done using the Chemical Solution Deposition (CSD) method that was prepared using the spin coating technique. The film was characterized using UV-Vis, X-Ray Diffraction (XRD), and I-V meters. The results showed that the greater concentration of Sr-doped made the crystallite size and resulted in the smaller percentage of transmittance. The transmittance value of Ba1-xSrxTiO3 film at all concentrations increased when the wavelength was 320 nm to 800 nm. The transmittance value < 50% means that the film has made the ability to absorb the light. I-V graph shifted in dark and light conditions when it was given a voltage so that it formed a diode graph. [ABSTRACT FROM AUTHOR]

The influence of alkali/alkali earth elements like lithium and strontium on optical properties of 60B2O3 - xLi2O - (40 – x) SrO - 0.3Sm2O3 (x=20, 15, 10 and 5 mol %) are reported. Concentration variation of Li2O and SrO alters the structure of the glass network which endow with more non-bridging oxygen's (NBO's) that could affect the optical properties. The glass samples are prepared by melt quenching technique. The non-crystalline nature of the glasses was confirmed through XRD. The structural and optical properties were understood by spectroscopic techniques through UV-VIS-NIR, FTIR and Photoluminescence. It is observed that, the density of glasses increase with increase in the strontium concentration up to 30 mol%. Optical Band gap was evaluated. The IR study shows the presence of various borate groups in the wavelength range between 400 cm−1 to 1600 cm-1. The photoluminescence spectra consists of three prominent emission bands which makes these glasses compatible for reddish orange solid state optoelectronic devices. [ABSTRACT FROM AUTHOR]

We report the Raman spectroscopy studies on the strontium and ruthenium doped pyrochlore iridate compound Eu2Ir2O7. Eu2Ir2O7 is Weyl semimetallic oxide which exhibits metal-insulator transition at around 120 K. Strontium doping at the Europium site increases the metallic behavior and the metal-insulator transition temperature also lowers systematically with increasing doping concentrations.Ruthenium doping in the iridium site turns the compound to be completely insulating. The Raman spectroscopy studies show a systematic variation of specific Raman modeswith doping which involves Ir-O-Ir bond bending, Ir-O, and Eu-O bond stretching. Clear variations of peak positions have been observed for T2g(1), A1g and T2g(4) modes. The variations of electron-phonon interactions reflected in the Raman peaks can be attributed to the different electronic ground states of the doped samples. We have also corroborated the Raman peak shifts with the structural parameters obtained from XRD data. [ABSTRACT FROM AUTHOR]

A commercially available blue persistent phosphor was analyzed using thermoluminescence in the new General Order Kinetics formalism. From the analysis, it is seen that the TL curve of a blue persistent phosphor can be described by seven TL peaks with the activation energy ranging from 0.666-1.14 eV. The frequency factor is in the range from 108-109 sec−1. The value of η is the range of 0.012≤η≤0.154, which suggests that about 1-15% of the empty traps takes part in the retrapping of electrons from the conduction band. Again, from the ratio of N/no it is seen that the material consists of abundant empty traps. The luminescence lifetime of the blue persistent luminescent material Sr4Al14O25:Eu2+Nb3+ ranges from 0.65hr to 1.3 x 108 hrs at 300°K. The persistence luminescence of Sr4Al14O25:Eu2+Nb3+ at room temperature is due to the trap at 362.9°K. [ABSTRACT FROM AUTHOR]

The polycrystalline material Sr(Bi3.9-xNdxLa0.1)(Ti3.975Zr0.025)O15 with variation of neodymium content from 2.5 to 10 wt% was prepared by solid state method. XRD analysis indicated the formation of a single- phase orthorhombic structure. SEM analysis revealed the formation of plate like structure. It was also observed that with increase in the content of Nd, the values of Curie temperature (Tc) and dielectric constant (ε) were increased and the tolerance factor (t) decreased. It was found that the remnant polarization, piezoelectric charge and electromechanical coupling coefficients were increased up to certain extent of Nd doping and further increase of Nd content decreased. [ABSTRACT FROM AUTHOR]

Bioactive glass (BG) has a broad variety of biomedical applications because of its distinctive ability to bond with bone by exchanging ions in simulated body fluid when implanted inside the body, it has drawn enormous interest. Osteoporosis is a main cause of loss of bone density and that adding strontium (Sr) to the matrix of bioglass stimulates bone formation and also increases bone density and mass. This study concerns sol-gel derived Sr doped bioactive glass (BG) (50.77SiO2−24.12Na2O–(23.39-x)CaO–xSrO–1.72P2O5) in the quaternary (SiO2−Na2O-CaO-P2O5) system (x=0, 3, 5 and 8 mol%).The effect of Sr on bone nodule-like formation was conducted by using Calcified Nodule Staining Kit (Cosmo Bio Co., Ltd) after 28 days culture with MC3T3-E1 osteoblast-like cells (Riken Cell Bank, Tokyo, Japan). In XRD, the amorphous peak is slightly shifted to lower 2θ° value after SrO was incorporated into BG. Mineralization staining revealed that the larger area of mineralized nodules was detected on Sr (3) BG than others. These results suggest that BG with SrO 3% is a good candidate for bone tissue engineering with fast bone formation. [ABSTRACT FROM AUTHOR]

Magnesium alloys have gained significant interest as a structural material for automotive and aerospace applications due to its low-density, high durability and decent castability. As a result, these light alloys possess a promising potential. However, the limitation of low corrosion resistance constraint their practical applications. The aim of this paper is to investigate the corrosion behaviour of AZ31 magnesium alloy by conducting immersion test. This test was intended to determine the resistance of a material to an aggressive, aqueous environment by analysing the weight loss of the sample. Three types of sample were prepared namely bare, phosphated and Sr-P pretreated magnesium alloy. The samples were immersed in 3.5 wt.% sodium chloride solution at 25 °C for 24 and 72 hours. Moreover, scanning electron microscopy (SEM) was used to observe the surface of coatings and corrosion product on the test samples. The weight loss values are 4.39x10-2 g/cm2 and 4.52x10-2 g/cm2 for bare, 2.12x10-2 g/cm2 and 3.11x10-2 g/cm2 for unpretreated, 1.14x10-2 g/cm2 and 1.17x10-2 g/cm2 pretreated samples after immersion for 24 and 72 hours respectively. The findings show the decreased in weight loss values as the sample being treated. It also discovered that the immersion time has an inversely proportional relationship with the corrosion rate. It was observed that pretreated sample have a finer phosphating grain coverage area that improved the corrosion resistance performance. [ABSTRACT FROM AUTHOR]

Frequency dependent dielectric properties of orthorhombic rare earth manganite; Dy0.55Sr0.45Mn0.8Fe0.2O3 at various temperatures revealed multiple relaxation times indicating non-Debye model. Analysis of ac conductivity data showed three dimensional Variable Range Hopping (VRH) type of conduction at low temperatures. Nyquist diagrams displayed depressed semi circles pointing to inhomogeneities in the system where conductivity is influenced by multivalent charge carriers, grains and grain boundaries. [ABSTRACT FROM AUTHOR]

We have analyzed the magnetic interactions in Mn-site doped Nd0.67Sr0.33MnO3 system with Ru and Ni doping. The polycrystalline samples are prepared through conventional solid-state reaction route. The room temperature XRD patterns are recorded and analyzed using Rietveld refinement technique to confirm the single phase formation of the samples. The magnetization versus temperature graphs reveal the Curie temperature (TC) for all the samples. The paramagnetic region is fitted using Curie-Weiss model and significant parameters are calculated. Magnetization versus applied field graphs are plotted at room temperature and at 5K to determine the change in magnetic moment of the samples with respect to substitution. [ABSTRACT FROM AUTHOR]

In the present study, undoped strontium aluminate (Sr3Al2O6) nanoparticles were prepared using sol-gel method. The aim of the work is to investigate the role of strontium aluminate as a phosphor host material. Structural and linear optical properties of undoped strontium aluminate were investigated using X-ray diffraction, diffuse reflectance and photoluminescence measurements. The XRD pattern revealed that the sample is a single phase cubic structure with crystallite size 27nm. It is found that the nanocrystalline Sr3Al2O6 possesses some luminescence property on exciting with 280nm in blue region. [ABSTRACT FROM AUTHOR]

Self-cleaning application of metal oxide thin films has been the topic of research interest in the recent years. In this work surface wetting characterization of spray deposited Sr doped SnO2 thin films is presented. Strontium doped tin oxide films are polycrystalline with tetragonal structure having preferential growth along (1 0 1) and (2 1 1) planes. The films are uniform, crack-free and transparent in the visible region. The surface energy of SnO2:Sr thin films increases when the concentration of Sr increases up to 1wt% but decreases at 1.5wt% of doping. The spectroscopic ellipsometric data of SnO2:Sr was used to estimate variation of packing density in SnO2:Sr films. Packing density decreases with Sr concentration up to 1wt%, but increases at 1.5wt% of Sr. The contact angle measurements at different concentration of Sr indicate increase in the hydrophobicity of SnO2:Sr (1.5wt%) thin films. This property is ascribed to combined effect of variation in surface energy and packing density. The hydrophobicity of SnO2:Sr (1.5wt%) can be utilized in developing self-cleaning surfaces needed in the outdoor opto-electronic device installations as well as on windows of aircrafts and buildings. [ABSTRACT FROM AUTHOR]

Synthesis of conducting polyaniline and its compounds was carried out by chemical oxidative polymerization method using ammonium persulfate as an oxidizing agent. During polymerization of aniline, 10wt%, 20wt%, 30wt% and 40wt% Strontium dinitrate Sr(NO3)2 was added to modify the properties of polyaniline. Prepared samples were characterized by FTIR (Thermo Fisher Model Nicolet iS5) spectroscopy for the analysis of functional groups present in the composites. The sharp peaks at 705 and 855.8 cm-1 are the characteristic peaks of Sr(NO3)2. XRD studies clearly show the change in structural properties with increase in the concentration of Strontium nitrate in composites. The electrical properties were characterized by Keithley 2450 source meter. Linear I-V graph shows ohmic contact and electrical current decreases with the increase in the concentration of the Sr(NO3)2. This result may be due to the creation of grains created by the Sr in the composites. These obtained results were discussed and presented in this paper. [ABSTRACT FROM AUTHOR]

A study of ADC 12 (Al-Si aluminum alloy) composite is conducted as the more sustainable option of material in the automotive industry due to its durability, good elastic modulus, thermal stability, wear resistance, and high strength properties. This research is performed to identify and recognize the effect from the addition of SiC reinforce on the metal composite with aluminum act as the matrix. In this sstudy, the composite will be fabricated through a stir casting process where stirring is performed mechanically with a stirrer 4 times, 10 seconds each time with 2 seconds interval between them. Then, 1, 3, 5, 7 to 10 vf.% (volume fraction) SiC was added to each of the composite, the addition of 5%, 0,04%wt strontium, and 0,15%wt TiB were believed to enhance wettability, modify the silicon eutectic phase, and acts as the grain refiner respectively. The result obtained in this research showed an increase in hardness ADC12 composite with higher SiC content, but the result showed an optimum tensile strength is at 3 vf.% SiC. Thus, It is believed that strengthening and weakening factors from the reinforcing particle and metal matrix could neutralize the effect of each other until the optimum point of 3 vf.% SiC exhibits the maximum toughness, with tensile strength and hardness values of 236 MPa and 46 HRB respectively. [ABSTRACT FROM AUTHOR]

Aluminum matrix composite (AMC) was one of the promising materials for railway brake shoe, replacing gray cast iron since it has a low density and great combination between strength and wear resistance. The addition of boron carbide (B4C) which reinforced aluminum ADC12 as matrix showed better interfacial bonding than other ceramic reinforcement such as silicon carbide and alumina. However, B4C has some serious problem when used in a large amount which will decrease the wetting properties. In this study, the fabrication of AMC was carried out with the addition of 1 to 10 vf.% reinforcement through stir casting and 2 minutes argon degassing process. Magnesium as a wetting agent, Titanium-boron as a grain refiner, and strontium as a modifier were added to improve its mechanical properties. Microstructure and mechanical properties of AMC were investigated by performing Optical Microscope (OM), Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), and destructive test. The result showed that the addition of 7 vf.% B4C was the optimum variation which increased the tensile strength with the value of 231.117 MPa and hardness of 58.34 HRB also decreased impact resistance with value of 0.09375 J/mm² and wear rate 0.00326 x 10-5 mm/m³. [ABSTRACT FROM AUTHOR]

90Sr, as one of the nuclear waste materials with the highest yield, has the potential to pollute the environment if an accident occurs in nuclear power plants. So in this study MOFs who have very small pores, cavity shapes and structured geometry used as adsorbent material to purifying Sr waste. 25 mg of mass adsorbent was used to 100 ml volume of the sample. The operating temperature was variated into 25 °C, 35 °C, and 45 °C. Variations of the initial concentration used in the sample were 100 ppm, 50 ppm, and 25 ppm. Then the sampling points have been determined in the 10th, 30th, 40th, 50th, 60th, 90th and 120th minutes. The AAS test was used to determine the Sr concentration of the solution which was successfully adsorbed. One way ANOVA test was used to analyzing the effect of temperature on the adsorption process. Adsorption modeling test was carried out according to Langmuir and Freundlich isotherm model. The variation of the concentration of the main solution in the strontium isotherm adsorption process in the test solution has an effect on the adsorption process conducted by HKUST-1. Variation of operating temperature in the adsorption process also takes an effect of that strontium adsorption process in the test solution. That is, with the highest temperature of 45 °C, the adsorption capacity that is owned is the highest adsorption capacity of 434.78 mg / g. In general, both of the Langmuir and Freundlich isotherm adsorption models are matched to this strontium isotherm adsorption process using HKUST-1 adsorbent. [ABSTRACT FROM AUTHOR]

High Temperature Superconductor TBCCO-based cuprate material becomes an interesting material in cryogenic area since it has many superconducting phases. The improvements of this material have been made by atom substitutions as well as methods of preparation. The different number of CuO layers in Tl-based cuprate can be used to investigate the effect of different numbers of Cu–O layers as well as the role of agent doping in the mechanism of superconductivity in the cuprates. By using conventional method, the addition of Cr to (Tl1-xCrx) Sr2CaCu2O7-δ with x= 0.0, 0.05, ..., 0.20; critical temperature in the range of 91K to 105K. The (Tl1-xRhx) Sr2CaCu2O7-δ showed changes in room-temperature resistivity and sample with x = 0.20 showed the highest Tc-onset (91K). The electrical resistivity of (Tl1−xCrx) Ba2Ca2Cu3O9−δ for x = 0.4–0.8 samples showed Tc-onset at around 124K. Samples with nominal starting composition Tl2Ba2CaCu2O8 (CdTe)x with x = 0 to 0.20 weight percent (wt.%) have been prepared by the solid-state reaction method. The critical onset temperature, Tc-onset for all samples was between 104K and 108 K while the critical zero resistance temperature, Tc-zero was from 93K to 95K. It was found that the addition of nano Ag decreased the critical temperature and phase formation of (Tl0.85Cr0.15) Sr2CaCu2O7-δAgx. HTSC (Tl2-xCrxBa2CaCu2O8-δ) showed a Tc-zero of 96K and Tc-onset 116K for x = 2. Whereas a high Tc-zero of 100K and Tc-onset of 115K was found in (Tl1.9Te0.1Ba2CaCu2O8-δ) system. Based on the most results of experiments, it can be concluded that TBCCO with toxic precursor is in high temperature superconductor. The presence of doping agent was effective only in a few moles. It was observed that phase formation affected the critical temperature. [ABSTRACT FROM AUTHOR]

Strontium and Niobium doped CCTO with the chemical composition Ca0.95Sr0.05Cu3Ti3.98Nb0.02O12 was processed by conventional solid state reaction method. X-Ray diffraction pattern confirmed the single phase formation of the synthesized sample. Dielectric measurement performed to study the frequency and temperature effect on the dielectric constant as well as dielectric losses of the prepared sample. Temperature and frequency dependent conductivity studies were carried out in the temperature range 293K to 573K and frequency in the range of 1Hz to 10MHz. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) is the most stable Calcium Phosphate salt (also known as Bone-mineral) which is present as inorganic part of human hard tissues having applications in orthopedics, dentistry, archeology, chromatography, environmental remedies as waste water treatment, pollutant gas adsorbent and so on. In this study an attempt is made to synthesize pure Hydroxyapatite and 5 wt% Strontium doped Hydroxyapatite (Sr doped HA) NPs using sono-chemical assisted hydrothermal technique. Strontium (Sr) is an essential trace mineral present in bone and it improves biological properties of HA so Sr is selected as dopant. Synthesized samples were characterized by X-Ray Diffraction (XRD), Fourier Transform Infrared (FT-IR) spectroscopy and Energy Dispersive X-Ray (EDX) Analysis. XRD analysis shows that XRD data of both samples match well with standard data (JCPDS Card No.- 09-0432) and have hexagonal crystal symmetry. Sr substitution in HA lattice increase cell parameters and shift diffraction peaks slightly to the lower value of diffraction angles. FT-IR analysis shows that all the characteristic transmission bands of Phosphate and hydroxide groups along with peaks of adsorbed water are present in FT-IR spectra of pure and Sr doped HA. However, transmission peaks of Nitrate are also present due to the fact that Nitrate compound was utilized in the reaction as calcium source. EDX analysis shows the presence of Sr ion in HA lattice. Ca/P ratio was 1.98 and 1.88 for pure HA and Sr doped HA respectively. High Ca/P ratio might be found due to presence of small amount of amorphous intermediate Calcium Phosphate phases or due to formation of Tetra-calcium Phosphate. [ABSTRACT FROM AUTHOR]

The Strontium Calcium Oxalate (SCO) single crystals were grown by using silica gel technique. Different parameters such as gel density, concentration of oxalate solution, concentration of reactants, gel setting time have considerable effect on the growth rate. Study of FT-IR spectroscopy identifies water and other functional groups present in the grown crystal. A UVVisible- NIR spectroscopic study gives various linear optical constants like absorption, transmittance, reflectance, band gap, refractive Index and electrical susceptibility. [ABSTRACT FROM AUTHOR]

The paper describes the results of studying kinetics of cesium and strontium sorption by clinoptilolite modified by nickel-potassium ferrocyanide (the NPF-CL sorbent) from various aqueous media (tap water, 0.01 M NaCl and 0.1 M CaCl2 + 0.01 M NaCl solution) containing 100 mg/L cesium or strontium. The effect of composition of a solution on observed rate constants at the first and the third stages was determined. It was shown that chemical composition of a solution affected the observed rate constants of cesium and strontium sorption at the first (chemical transformation of the ferrocyanide phase due to heterogenic ion exchange reaction) and the second (precipitation of mixed ferrocyanides phases in micropores of the sorbent) stages of the sorption process. Changes of surface texture and porosity of the sorbent after cesium and strontium sorption were determined using the methods of scanning electron microscopy and low temperature nitrogen adsorption. [ABSTRACT FROM AUTHOR]

The sorption capacity for strontium of natural (clinoptilolite and glauconite) and modified aluminosilicates by mixed ferrocyanide nickel-potassium was studied. It was shown that clinoptilolite-based samples have a higher specificity for strontium. The distribution coefficient of strontium by natural clinoptilolite and mixed nickel-potassium ferrocyanide based on clinoptilolite were respectively 10(3,8±0,4) H 10(3,1±0,4) ml/g. Static exchange capacity for strontium modified samples based on glauconite and clinoptilolite: 148 H 137 mg/g. The process of sorption of strontium proceeds in the pore-diffusion mode. The calculated diffusion coefficients for all samples were 10-13 m²/s. [ABSTRACT FROM AUTHOR]

Polycrystalline samples of La0.7Ba0.1Sr0.2Mn1-xCuxO3 (x = 0, 0.10) have been prepared by the sol-gel method. The x-ray diffraction (XRD) analysis shows both samples have achieved single phase state. Moreover, both samples crystallize in rhombohedral structure with R3̅c space group. Further analysis shows that copper reduces the unit cell volume of the sample, while at the same time reduces the average crystallite size of the sample. Copper substitution also leads to a slight distortion in the crystal structure of the sample. Scanning electron microscope (SEM) result reveals that copper substitution leads to a smaller grain size. Vibrating sample magnetometer (VSM) measurement at room temperature shows that copper substitution reduces the saturation of magnetic moment in the sample. This result indicates that copper substitution weakens the ferromagnetic property of the sample at room temperature. [ABSTRACT FROM AUTHOR]

Cerium Europium co-doped Strontium barium niobate (SBN) nano ceramic systems at different concentrations were prepared by sol gel method. The structural properties were characterised by X-ray diffraction, FTIR and Raman spectroscopy. X-ray diffraction analysis confirms the tetragonal structure of the prepared system. EDAX analysis confirms the components present in the sample. SEM image shows the needle like morphology of the nano system. XRD image confirms the particle size and crystalline planes of the prepared nanosized cerium europium doped SBN with the standard value. The broad absorption peak at 291 and 273 nm were observed for 0.1, 0.2 % Cerium, Europium co-doped SBN nano system. The absorption in the samples is from direct transition and the values of energy gap were calculated as 2.11 eV and. 2.27 eV. Photoluminescence studies shows the broad emission peaks at 419, 447, 493 nm due to 5d-4f Ce3+ transition levels. The peaks at 440, 449 nm were also observed due to the emission from SBN and less intense peaks at 558, 576, 588 nm due to the 5D0—7F0, 7F1 transitions of Eu3+ when excited at 305 nm wavelength. From the measured luminescence decay profiles, the tri-exponential lifetime of the 0.1% Cerium, Europium co-doped SBN nano system was calculated at 440 nm emission wavelength. Therefore the cerium europium co-doped SBN can be used for optical applications. [ABSTRACT FROM AUTHOR]

The present study is an exploration of a.c impedance study and dielectric properties of IPANI/Ag/SrTiO3 (PAS) composites synthesized by in-situ oxidative interfacial polymerization spending (NH4)2S2O8 at ice-cooled temperature. The prepared samples were characterized by using various physical methods viz., FT-IR, XRD and their thermal behavior was studied by DSC techniques. FT-IR and XRD profile reveals the formation of PAS-50% composite and distribution of particles homogeneously in the polyaniline matrix. The increased thermal stability of the synthesized PAS-50% composite may be due to interfacial interaction of IPANI with SrTiO3 crystallites embedded with silver nanoparticles evidenced by XRD studies. The real and imaginary dielectric constant values of the PAS-50% composite decreases with increasing frequency. [ABSTRACT FROM AUTHOR]

Nano-sized particles of W-type hexaferrites having chemical composition SrCo2AgxFe16-xO27 (x = 0.0, 0.1, 0.2, 0.3) was synthesized by sol gel auto-combustion technique. The structural, morphological and elemental distribution of synthesized nanohexaferrites was studied by using techniques such as XRD, FESEM, EDS. From the XRD analysis, the crystallite size is found to be in the range of 51-61 nm calculated by using Debye-Scherrer formula which means crystallite size increases with increase in silver concentration. FESEM analysis revealed that grains are hexagonal in shape. The EDS spectra of the prepared samples confirming the formation of pure nanohexaferrites and elemental composition infer that no elements except strontium, cobalt, silver, iron and oxygen are present in the synthesized samples. [ABSTRACT FROM AUTHOR]

Silver doped strontium calcium silicate amorphous microspheres were synthesized via a simple sol-gel method. The morphological and microstructural properties of the materials were investigated through electron microscope with selected area electron diffraction pattern, Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (XRD) methods. XRD and electron microscopy studies clearly reveal the amorphous nature of the samples with micron-sized spheres. FTIR shows the possible vibrations of silicate groups. Antibacterial effects of the sample were investigated with various microbiles by using agar well diffusion method. Incubation zones against E-coli and S aureus are found to be 19 and 19.3 mm respectively.Bone like apatite formation is also found on the surface of the sample through in-vitro studies. [ABSTRACT FROM AUTHOR]