Response evaluation of a compact and highly efficient neutron diffractometer for compact accelerator neutron sources

We fabricated the spheroid neutron diffractometer with 79 neutron detector rings using the transparent rubber sheet type Eu:LiCaAlF6 scintillators and wavelength-shifting fibers.We confirmed that the fabricated detector shows a clear neutron peak and can discriminate neutron and gamma-ray events in a signal pulse spectrum.We additionally checked that the fabricated diffractometer can detect a neutron diffraction peak of ferrite powder at Kyoto University Accelerator-driven Neutron Source.Consequently,it can be expected that crystal structural analysis will be possible even by small accelerator neutron sources.

A study on some elements and their phases in sediments of Changjiang Estuary by X-ray spectrometer and X-ray diffractometer

INTRODUCTIONThe studies on the quantitative distribution of the conventional elements and their phases in the sediments of the Changjiang Estuary are of great importance to the understanding of the chemical processes of ion exchange, absorption, desorption and flocculation in the estuary.

Effect of sodium nitroprusside on the microrheological properties of red blood cells in different media

Red blood cell(RBC)aggregation as well as their deformation significantly affects blood microrheology.These processes depend on various factors,one of which is concentration of the nitric oxide,one of the main signaling molecule in the bloodstream.The purpose of this study was to investigate the effect of nitric oxide on the microrheological properties of red blood cells(RBCs)in RBC samples of various media after the addition of nitric oxide donor sodium nitroprusside in vitro.Microrheological properties were measured using laser aggregometer and ektacytometer based on diffuse light scattering and diffraction of laser light on a suspension of RBCs,respectively.The study found that heparin-stabilized blood showed increased RBC aggregation and deformation with sodium nitroprusside concentrations of 100,and 200M,while EDTA-stabilized blood showed slightly decreased aggregation and unchanged deformation.With washed RBCs in dextran solution,the addition of sodium nitroprusside(in the concentrations of 100,and 200M)resulted in decreased aggregation and increased deformation.These-ndings aid in our understanding of nitric oxide's effect on RBC microrheological properties.

The neutron texture diffractometer at the China Advanced Research Reactor

The first neutron texture diffractometer in China has been built at the China Advanced Research Reactor,due to strong demand for texture measurement with neutrons from the domestic user community. This neutron texture diffractometer has high neutron intensity, moderate resolution and is mainly applied to study texture in commonly used industrial materials and engineering components. In this paper, the design and characteristics of this instrument are described. The results for calibration with neutrons and quantitative texture analysis of zirconium alloy plate are presented. The comparison of texture measurements with the results obtained in HIPPO at LANSCE and Kowari at ANSTO illustrates the reliability of the texture diffractometer.

Radiological and X-Ray Diffraction Characterization of Bauxite and Rutile Ore Contaminated Environment in Kanam and Wase Mineral Exploration Sites, Plateau State-Nigeria

Two non-destructive analytical techniques (gamma spectrometer and X-ray diffractometer) were employed in the analysis of bauxite and rutile ore and their vicinity soil and control sourced within the Kanam and Wase mineral exploration sites. The activity concentrations of natural radionuclides 238U, 232Th, and 40K in the soil samples received from bauxite and rutile mineral mining vicinities revealed high concentrations of 238U, 232Th, and 40K compared to the control soil samples sourced 500 m away from the mineral exploration vicinities. Radiological detriments RLI, AUI, Hin and Hex unveiled values exceeding the radiation standard concentration (>1) for soil. X-ray diffraction characterization of bauxite ore revealed the interlocking minerals of Bauxite (18)%, Albite (11)%, Garnet (15)%, Illite (6)% and Muscovite (43)% in various proportions obtained within the 2θ range (9.18 to 64.4) and a peak value (intensity, cps) of 3400. Pure bauxite percentage in the ore meets metallurgical grade (15 - 25)%. X-ray diffraction of rutile ore revealed the minerals of rutile (40)%, quartz (21.4)%, ilmenite (27)% and garnet (11.8)% found within the 2θ range (27.5 to 35.6) and a peak value intensity of 31.1 - 100.0 cps also meeting the metallurgical grade of 15% - 25%. The major environmental concern associated with the mineral-sands industry is the radiation hazards, pollution of ground-water sources from heavy metals, mineral transport with heavy equipment’s, dredging operations in fragile coastal area and clearing of vegetation.

Mechanical properties and acoustic emission characteristics of thick hard roof sandstone in Shendong coal field

The mechanical properties and acoustic emission characteristics of thick hard roof sandstone were investigated. Samples were taken from the 30.87-m thick sandstone roof in a mine in the Shengdong coal field, China. Firstly, the composition and microscopic characteristics were analyzed by XRD and FE-SEM, respectively. Moreover, the indirect tensile test, uniaxial compression test, three axis compression experiment and AE test are carried out by using RMT-150C mechanics experiment system with DSS-8B AE test system. The experiment results indicate that the main framework particles of sandstone are quartz and feldspar, and mainly quartz. Cements are mainly pyrite, kaolinite, chlorite and zeolite cross needle, clinochlore, and clay minerals. The microstructure of sandstone is very dense, with few pores and high cementation degree. The tensile strength, compressive strength and elastic modulus of sandstone are 4.825, 85.313 MPa, 13.814 GPa, respectively, so the sandstone belongs to hard rock. The AE cumulative counts of sandstone can be divided into three phases： relatively flat growth period, rapid growth period and spurt period. The signal strength of AE waveform can be used as a warning signal. In the tensile fracture zone, the warning value is 0.4 mV, and in the compression shear failure zone, it is 4 mV. The numbers of cumulative counts of AE under different stress conditions have obvious difference. Moreover, the growth of cumulative counts of acoustic emission is more obvious when the stress is more than 60% of the peak stress.

Pressure dependence of the thermal stability in LiMn_(2)O_(4)

Structural stability in terms of the decomposition temperature in LiMn_(2)O_(4) was systematically investigated by a series of high-temperature and high-pressure experiments.LiMn_(2)O_(4) was found to have structural stability up to 5 GPa at room temperature.Under ambient pressure,the compound decomposed at 1300℃.The decomposition temperature decreased with increasing pressure,yielding more complex decomposed products.Below the decomposition temperature,the crystal structure of LiMn_(2)O_(4) varied with pressure.The presented results in this study offer new insights into the thermal and pressure stability of LiMn_(2)O_(4) materials as a cathode for lithium-ion batteries that can operate under extreme conditions.Therefore,these findings may serve as a useful guide for future work for improving lithium-ion batteries.

Isotropic Thermal Expansivity and Anisotropic Compressibility of ReB2

We experimentally investigated some of the mechanical properties of ReB2 under high temperature/pressure(TIP)conditions.High-T experiments(up to 600℃at 1 atm)were carried out in a high-T oven attached to a conventional x-ray diffractometer whereas high-P experiments(up to about 42 GPa at 25℃)were conducted in a diamond-anvil cell using synchrotron x-ray radiation.High-T data suggest a highly isotropic thermal expansivity whereas high-P data suggest a highly anisotropic compressibility for ReB2.

Dy substitution effect on the temperature dependences of magnetostriction in Pr_(1-x)Dy_xFe_(1.9) alloys

The temperature dependences of magnetostriction in Pr（1 x）DyxFe（1.9）（0 ≤ x ≤ 1.0） alloys between 5 K and 300 K were investigated.An unusual decrease of magnetostriction with temperature decreasing was found in Pr-rich alloys（0 ≤x ≤ 0.2）,due to the change of the easy magnetization direction（EMD）.Dy substitution reduces the magnetostriction in high-magnetic field（10 kOe ≤ H≤90 kOe） at 5 K,while a small amount of Dy substitution（x = 0.05） is beneficial to increasing the magnetostriction in low-magnetic field between 10 K and 50 K.This makes the alloys a potential candidate for low temperature applications.

Chemical Composition and Crystal Structure of the Eggshell of the Green Crested Lizard Bronchocela cristatella(Agamidae)

The majority of extant reptiles are oviparous and produce eggs with three major components:embryo,yolk,and eggshell.The eggshell is species-specific and more diverse in squamate reptiles than in other amniote taxa.Here,we study the crystal structure,chemical composition,and bonding states of the eggshell of the green crested lizard Bronchocela cristatella.X-ray diffractometer(XRD)analysis showed the existence of two clearly defined and distinguishable crystalline phases,aragonite and calcite.Using the XRD data and a unit cell refinement routine,we identified two sets of cell parameters:a=4.956 A,b=7.965 A,and c=5.734 A for the aragonite phase;a=4.987 A,b=4.987 A,and c=17.056 A for the calcite structure.We used x-ray photoelectron spectroscopy to examine detailed elemental composition and bonding states and found that the eggshell was composed primarily of elements C,N,Ca,and O,with C,N and O bonded to various types of hybridization in the protein of the eggshell membrane.The Ca:C:O ratio for the calcium carbonate yielded a value of-7:8:21,which is close to the expected stoichiometric value of CaCO3.

Growth of Erbium Dihydride Films under Low Hydrogen Pressure by Pulsed Laser Deposition

Erbium dihydride thin films were prepared by pulsed laser deposition on Si（100） substrates using erbium target under different low hydrogen pressures. The properties of these films were examined by atomic force microscopy, X-ray diffractometer, transmission electron microscopy, and Fourier transform infrared spectroscopy and UV-vis spectroscopy. Surface morphology reveals the smooth surface of these films （RMS： from 0.503 to 2.849 nm）. The presence of obviously-broadened peaks for diffraction planes （111） suggests a presence of very tiny crystallites distributed along a preferred crystallographic orientation. Transmission electron microscopy investigations confirmed the formation of tiny crystallites due to the implantation of erbium ions. Due to the increase of nominal H concentration, the intensity of the broad absorbance from 190-260 nm increased.

Impact of Modification Process on Graphite Structure at Application of Chloroperfluorododecylfluoro Sulfate

Impact of the process of modification on graphite structure at the application of fluorine-containing oligomer-FDS （chloroperfluorododecylfluoro sulfate） has been studied. It was shown that during this process graphite structure does not change. Only particles of FDS are destructed into monolayers, which are spread in graphite intercrystalline voids. At the mechanical impact it protects graphite from destruction and correspondingly, improveing some of its tribotechnical characteristics.

Characterization of the Thermo-Microstructural Analysis of Raffia Palm Fibers Proposed for Roofing Sheet Production

Raffia fibres are made from fibrous branches and leaves of Raffia palm. The membrane on the underside of each individual frond leaf is taken off to create a long thin fiber. They are usually waste materials which cause a great environmental degradation. The characterization of Raffia palm fibers/ particles was investigated through X-ray diffractometer (XRD), thermogravimetric analysis (TGA/DTA), Fourier transform infrared spectrometry (FTIR), Scanning electron mi croscope with energy dispersive spectrometer (SEM/EDS) and Atomic force microscope (AFM). The various results obtained are equivalent to those of other agro-waste materials generally used in roofing sheets composites production. Hence, this work shows that Raffia palm fibers/particles can be a useful material for cement mortar composites production which can be used for production of roofing sheets.

Effect of Water Content on Crystalline Structure of Ionic Liquids Mixture Pretreated Microcrystalline Cellulose (MCC)

Microcrystalline cellulose (MCC) was pretreated by using ionic liquids (ILs)-water mixtures solvent with solid acid catalysts. Different amount of water was considerate as the main variable. The peak shift of pretreated sample was determined by FT-IR related to the water content. The XRD was applied to characterize the change in MCC crystalline structure. Thermal decomposition technique was applied to investigate the thermal stability of pretreated MCC. The result indicated that three state of samples were occurred in pretreated MCC sample which was related the amount of water in ILs mixture system. XRD result suggested that the raw sample was distorted and transformed into a less ordered intermediate structure and the smaller crystallite size in lump state sample was obtained which could lead to lower thermal stability. This study revealed the physical chemicals properties, characteristic of molecular structures in MCC using ILs-water mixtures.

Ba13(BS3)6(SnS6):Synthesis,Crystal Structure,Electronic Structure,and Optical Property

A new zero-dimensional（0D） thioborate compound Ba（13）（BS3）6（SnS6）, the first one in the AE/B/Sn/Q（AE=alkali-earth metals; Q=S, Se, Te） family, has been synthesized by conventional high-temperature solid-state reaction. It crystallizes in the trigonal space group of R3（No. 148） with a=b=21.4634（6） , c=8.3653（5） , V=3337.4（2） 3, Z=3, Mr=2738.41, Dc=4.088 g/cm3, μ=12.977 mm（-1）, F（000）=3576, the final R=0.0208 and w R=0.0505 with I 〉 2σ（I）, 3.28〈θ〈27.49°, w=1/[σ2（Fo2） ＋（0.0253P）2 ＋ 0.0000P], where P =（Fo2 ＋ 2Fc2）/3, S=1.051,（Δρ）max=0.639 and（Δρ）min=–1.195 e/3. The structure is constructed by discrete [BS3]（3–） trigonal planes and isolated [SnS6]（8–） octahedra with Ba（2＋） cations filled among them. The IR spectrum indicates the presence of lighter element boron. Its optical band gap shown by the UV-Vis-near-IR spectrum is about 2.69 e V, which agrees well with the electronic structure calculation.

RESEARCH OF MACHINING SURFACE QUALITY OF ENGINEERING CERAMICS

Surface quality is an important sublect in the study of machining technology. Because thesurface quality of the ceramic parts has direct effect on their life and reliability, to improve the reliability of structural ceramic parts is an urgent problem which needs to be solved for their furtherwidespread. The authors have done a systematic investigation in the macrostate, geometrical to-pography, surface roughness, deteriorative layer, residual stress and phase change of the machiningsurface of engineering ceramic zirconia and sialon ceramics. Some findings and conclusions of im-portant referential value have been obtained.

Er_(2)O_(3) nanospheres with fast response to humidity for non-contact sensing

As a kind of lanthanide oxide functional material,Er_(2)O_(3) as aroused widespread scientific interest due to its exceptional properties;however,its humidity sensing performance remains to be explored.Herein,the rational designed Er_(2)O_(3) anospheres were prepared by one-step solvothermal and high-temperature calcined method.The structure and morphology of the samples were analyzed by X-ray diffractometer(XRD),scanning electron microscope(SEM)and transmission electron microscope(TEM),and the effect of calcination temperatures on humidity sensing characteristics was also investigated.

Influence of ash composition on the sintering behavior during pressurized combustion and gasification process

To determine the ash characteristics during fluidized bed combustion and gasification purposes, the investigation of the impacts of chemical composition of Jincheng coal ash on the sintering temperature was conducted. A series of experiments on the sintering behavior at 0.5 MPa was performed using the pressurized pressure-drop technique in the combustion and gasification atmospheres. Meanwhile, the mineral transformations of sintered ash pellets were observed using X-ray diffractometer （XRD） analyzer to better understand the experimental results. In addition, quantitative XRD and field emission scanning electron microscope/energy dispersive X-ray spectrometer （FE-SEM/EDS） analyses of ash samples were used for clarifying the detailed ash melting mechanism. These results show that the addition of Fe203 can obviously reduce the sintering temperatures under gasification atmospheres, and only affect a little the sintering temperature under combustion atmosphere. This may be due to the presence of iron-bearing minerals, which will react with other ash compositions to produce low-melting-point eutectics. The FE-SEM/EDS analyses of ash samples with Fe203 additive show consistent results with the XRD measurements. The CaO and Na20 can reduce the sintering temperatures under both the combustion and gasification atmospheres. This can be also contributed to the formation of low-melting-point eutectics, decreasing the sintering temperature. Moreover, the fluxing minerals, such as magnetite, anhydrite, muscovite, albite and nepheline, contribute mostly to the reduction of the sintering temperature while the feldspar minerals, such as anorthite, gehlenite and sanidine, can react with other minerals to produce low-melting-point eutectics, and thereby reduce the sintering temperatures.

Improving the performance of inverted organic solar cells by adjusting the concentration of precursor solution of Al-doped ZnO

Al-doped ZnO(AZO) has been used as an electron transport and hole blocking buffer layer in inverted organic solar cells(IOSCs). In this paper, the AZO morphology, optical and structural properties and IOSCs performance are investigated as a function of precursor solution concentration from 0.1 mol/L to 1.0 mol/L. We demonstrate that the device with 0.1 mol/L precursor concentration of AZO buffer layers enhances the short-circuit current and the fill factor of IOSCs simultaneously. The resulting device shows that the power conversion efficiency is improved by 35.6% relative to that of the 1.0 mol/L device, due to the improved surface morphology and transmittance(300–400 nm) of AZO buffer layer.

SYNTHESIS OF LEAD FREE SODIUM BISMUTH TITANATE(NBT)CERAMIC BY CONVENTIONAL AND MICROWAVE SINTERING METHODS

Dielectric studies were carried out on a lead free Sodium Bismuth Titanate,NBT,(Na_(0.5)Bi_(0.5)TiO_(3))composition.The material was synthesized by conventional ceramic method(CS)and microwave sintering(MS).The presence of single phase has been confirmed by X-ray diffraction and scanning electron microscopy of NBT ceramic.The later technique(MS)resulted in material with high density,dielectric properties and improved microstructure.The transition temperature was observed slightly higher for microwave sintered(MS)material.Longitudinal modulus measurements are very sensitive property to identify the phase transitions in ceramics.Longitudinal modulus(L)measurements were also employed on these samples in the frequency 136 kHz and can be studied in the wide temperature range 30℃to 400℃.The elastic behavior(L)showed a break at two temperatures(~200℃and 350℃)in both the conventional and microwave sintered ceramics.In NBT ceramics,permittivity anomalies are connected to modulus anomalies.The results are correlated with the dielectric measurements.This behavior explained in the light of structural phase transitions in the ferroelectric ceramics.