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X-ray spectra scattered at 90° by acrylic resin plates of various thicknesses are measured. The intensity and polarization of Compton-scattered X-rays are estimated from the spectra. As the thickness of the slab increases, the intensity increases but the polarization decreases. The optimal thickness for a polarized X-ray fluorescence spectrometer is determined, which provides both high intensity and high polarization.

The purpose of this study is to develop a novel welding torch with high wind resistance, which can be used for welding outside a building under strong cross-wind. In this paper, a parametric study was carried out using different torch nozzle designs and shield gas flow rates for their optimization. The gas flow around the torch nozzle exit was visualized through the shadowgraph method to evaluate the interaction between the shielding gas flow and the cross-wind. Nitrogen fraction in a weld bead was measured for confirming the shielding effect. Furthermore, CFD simulation was also carried out for obtaining shielding gas flow velocity at the torch nozzle exit. From the result of the above experiments and simulation, effective parameters for improving the shielding effect against the cross-wind were comprehensively discussed. As a result, the nitrogen fraction was found to be decreased by increasing the averaged vertical gas velocity at the torch nozzle exit. For achieving this, it is especially effective to decrease the nozzle diameter or increase the gas flow rate.

The displacement of one fluid by another is an important process, not only in industrial and environmental fields, such as chromatography, enhanced oil recovery, and CO2 sequestration, but also material processing, such as Lost Foam Casting. Even during hydrodynamically stable fluid displacement where a more viscous fluid displaces a less viscous fluid in porous media or in Hele-Shaw cells, the growing interface fluctuates slightly. This fluctuation is attributed to thermodynamic conditions, which can be categorized as the following systems: fully miscible, partially miscible, and immiscible. The dynamics of these three systems differ significantly. Here, we analyze interfacial fluctuations under the three systems using Family–Vicsek scaling and calculate the scaling indexes. We discovered that the roughness exponent, α, and growth exponent, β, of the partially miscible case are larger than those of the immiscible and fully miscible cases due to the effects of the Korteweg convection as induced during phase separation. Moreover, it is confirmed that fluctuations in all systems with steady values of α and β are represented as a single curve, which implies that accurate predictions for the growing interface with fluctuations in Hele-Shaw flows can be accomplished at any scale and time, regardless of the miscibility conditions.

In order to address the applicability of 3D printers to assembling a spectrometer, we made a compact energy dispersive X-ray fluorescence (XRF) spectrometer with the use of a 3D printer and applied it to the measurements of trace elements in multicomponent alloys. The spectrometer was made of polycarbonate. The X-ray path was in the air, and the distance between equipment was designed so as to obtain enough input count rate even though a low-power X-ray source was employed. As an X-ray source and a detector, we used a low-power X-ray tube (4 watts) and a silicon drift detector. Although the effect of scattered X-rays from resin materials on measured spectra should be taken into account, the 3D-printed spectrometer was comparable with the conventional spectrometer in terms of the qualitative analysis. By using the simple 3D-printed spectrometer, trace elements included in stainless steels and an Ni-based alloy could be detected. 3D printers should therefore provide a simple and quick way of making an improvement on analytical instruments combined with the conventional way.

Matsumoto M, Satoh, K, Kushi, H, Hamuro, K, Sakurai, M, Saito, H, Tanaka, R, Saito, T, Kohda, N, and Hamada, K. Salivary immunoglobulin A secretion rate during peak period conditioning regimens in triathletes. J Strength Cond Res 35(5): 1389-1396, 2021-Triathletes often feel unwell during the conditioning period (peak period) leading up to a race. The aim of this study was to evaluate the factors relevant to the condition of athletes and their impact on mucosal immune responses and the salivary immunoglobulin A (IgA) secretion rate. This study recruited college student triathletes (33 men and 7 women) who participated in an Olympic distance race. For each subject, the salivary IgA rate was measured continuously for 1 month before the race (peak period). Data on physical activity during the peak period were calculated in metabolic equivalents, and the relationships between these factors and the salivary IgA secretion rate were evaluated. The average amount of physical activity was highest during the 2- to 3-week period before the race, at 744.7 ± 51.5 kcal expended per day. In subjects who, on average, expended more than 1,000 kcal·d-1 in physical activity between 12 and 14 days before the race, the salivary IgA secretion rate was significantly reduced compared with the value at 1 week before the race (p < 0.05). On the day before the race, a further reduction was observed (p < 0.1). The salivary IgA secretion rate was decreased by high-intensity exercise during the peak period in advance of a race; this was associated with a loss of optimal condition just before the race.

While it is known that the performance of reverse osmosis membranes is dependent on their physicochemical properties, the existing literature studying membranes used in treatment facilities generally focuses on foulant layers or performance changes due to fouling, not on the performance and physicochemical changes that occur to the membranes themselves. In this study, the performance and physicochemical properties of a polyamide reverse osmosis membrane used for three years in a seawater desalination plant were compared to those of a corresponding unused membrane. The relationship between performance changes during long-term use and changes in physicochemical properties was evaluated. The results showed that membrane performance deterioration (i.e., reduced water flux, reduced contaminant rejection, and increased fouling propensity) occurred as a result of membrane use in the desalination facility, and that the main physicochemical changes responsible for performance deterioration were reduction in PVA coating coverage and bromine uptake by polyamide. The latter was likely promoted by oxidant residual in the membrane feed water. Our findings indicate that the optimization of membrane materials and processes towards maximizing the stability of the PVA coating and ensuring complete removal of oxidants in feed waters would minimize membrane performance deterioration in water purification facilities.

Deep-level luminescence at 3.3 eV related to the presence of Al vacancies (V Al ) was observed in room temperature photoluminescence (RT-PL) spectra of homoepitaxial AlN layers grown at 1450 °C by hydride vapor-phase epitaxy (HVPE) and cooled to RT in a mixture of H 2 and N 2 with added NH 3 . However, this luminescence disappeared after removing the near surface layer of AlN by polishing. In addition, the deep-level luminescence was not observed when the post-growth cooling of AlN was conducted without NH 3 . Secondary ion mass spectrometry (SIMS) studies revealed that although the point defect density of the interior of the AlN layers remained low, the near surface layer cooled in the presence of NH 3 was contaminated by Si impurities due to both suppression of the surface decomposition by the added NH 3 and volatilization of Si by decomposition of the quartz reactor walls at high temperatures. The deep-level luminescence reappeared after the polished AlN wafers were heated in presence of NH 3 at temperatures above 1400 °C. The surface contamination by Si is thought to generate V Al near the surface by lowering their formation energy due to the Fermi level effect, resulting in deep-level luminescence at 3.3 eV caused by the shallow donor (Si) to V Al transition.

Sum peaks, escape peaks, and diffraction peaks are considered artificial or spurious peaks in energy dispersive X-ray spectrometry. Experimental examples are given, which showed that escape and diffraction peaks can add up to become sum peaks. These artificial peaks are not weak, and great care must be taken to differentiate them from peaks due to impurity or trace elements. The relationship between the intensity of a sum peak and the original peaks is illustrated using computer simulation as well as probability theory. Copyright © 2016 John Wiley & Sons, Ltd.

To clarify the thermodynamic stability of a Mg-based long-period stacking ordered (LPSO) structure, we systematically study the energetic preference for alloys on multiple stacking sequences with different compositions for random mixing of constituent elements, Mg, Y, and Zn, based on special quasirandom structure (SQS). Through calculation of the formation free energy of SQSs, it was found that the Mg–Y–Zn alloy exhibits phase separation into Mg- and Y–Zn- rich phases, which is consistent with previous theoretical studies. The bulk modulus of SQSs for various compositions, stacking sequences, and atomic configurations is approximately 35 GPa, i . e ., it does not show significant dependence on the atomic arrangements, which therefore means that there are not significant differences among the effects of phonon on the stability of each structure in the LPSO structure. Introducing a stacking fault into hcp stacking sequence results in the acquisition of a “negative” energy, which indicates the profound relationship between the introduction of stacking faults and the formation of an LPSO structure.

A three-dimensional polarized X-ray fluorescence (XRF) spectrometer was assembled with a low-power X-ray tube of 40 milliwatts, and a sample of stainless steel was measured with an acrylic polarizer. Based on the Schrodinger’s wave picture of Compton scattering, the dependence of the de Broglie wavelength and the scattering angle of a recoil electron on the incident X-ray energy were calculated. When the incident X-rays were scattered at an angle of 90°, the de Broglie of the recoil electron always went away at an angle of 45° with the incident X-rays and the de Broglie wavelength varied for any wavelength of the incident X-rays, i.e. we could select the scattering angle of the recoil electron to be 45°according to the incident X-ray energy and it could then be regarded as 45° Bragg diffraction that could produce highly polarized X-rays. The polarization measurement of scattered X-rays from an acrylic and lead plates substantiated that Compton scattered X-rays from the acrylic plate had higher degree of polarization than the elastically scattered X-rays from the lead plate. Highly polarized Compton scattered X-rays from the light-element polarizer led to the background reduction and the changes of the characteristic X-ray intensity in XRF spectra measured by our laboratory-made spectrometer. Key words: polarized X-ray fluorescence spectrometer, stainless steel, acrylic polarizer, Compton scattering, background. DOI: http://dx.doi.org/10.15826/analitika.2018.22.2.010

Silver oxide clathrate Ag7O8M (M = NO3, HSO4) compounds were synthesized photoelectrochemically on rutile-type Nb-doped TiO2 single-crystal substrates. Epitaxial crystal growth was achieved for some clathrate compositions and substrate surface orientations, where commensurate growth is possible due to lattice matching between the pseudo lattice of the clathrate Ag6O8 cages and the TiO2 surface, similar to the well-known case of epitaxial C60 growth on single-crystal substrates. Particularly for the growth of Ag7O8NO3 on Nb-doped TiO2(110), fully (111)-oriented epitaxial crystallites without any other orientations were obtained. The selectivity for Ag7O8NO3 growth and the suppression of the formation of by-products, such as O2, were found to depend on the electrode potential. The highest selectivity was obtained at +0.2 V vs. Ag in a 0.01 M AgNO3 solution. An investigation of Ag7O8(MM′) (M = NO3, M′ = HSO4) depositions from solutions with different AgNO3 and Ag2SO4 mixing ratios showed that the growth of Ag7O8HSO4 is much faster than that of Ag7O8NO3. The process of incorporating monovalent M anions into the clathrate Ag6O8 cages was identified as the rate-limiting step for the growth of silver oxide clathrate compounds.

We investigate the formation of long-period stacking ordered (LPSO) structure for Mg-Y-Zn ternary alloys based on the short-range order (SRO) tendency of energetically competitive disordered phases. We find that unisotropic SRO tendencies for structures with stacking faults cannot be simply interpreted by arithmetic average of SRO for constituent fcc and hcp stackings, indicating that the SRO should be significantly affected by periodically-introduced stacking faults. We also find that SRO for neighboring Y-Zn pair, which should have positive sign to form specific L12 type cluster found in LPSO, is strongly affected by the distance between stacking faults: e.g., five atomic layer distance does not prefer in-plane Y-Zn pair, while seven atomic layer distance prefer both in- and inter-plane Y-Zn pair. These facts strongly indicate that ordering tendency for the Mg-Y-Zn alloy is significantly dominated by the stacking faults as well as their periodicity. We also systematically investigate correlation between SRO for other Mg-RE-Zn (RE = La, Tb, Dy, Ho, Er) alloys and the physical property of RE elements. We find that while SRO for RE-Zn pair does not show effective correlation with atomic radius, it has strong quadratic correlation with atomic radius considering unisotoropy along in- and inter-plane directions., 4 pages, 3 figures

An experimental study of immiscible viscous fingering (VF), formed during the injection of surfactant solutions into viscous oil in a radial Hele-Shaw cell, in which both fluids are Newtonian, is described. VF in such a system is related to the enhanced oil recovery method known as surfactant flooding and to the recovery of residual nonaqueous phase liquids (NAPLs) in aquifers. Previous studies show that, for a given viscosity contrast, immiscible VF formed by Newtonian fluids is dominated by the capillary number, which is defined as the ratio between the viscous force and the interfacial tension, and that the finger width decreases with increasing capillary number. However, in the present study, phenomena contrary to these rules were observed: wider fingers occurred in the surfactant solution system compared to those in the water system, in the nonlinear stage of VF evolution, despite the fact that the capillary number had the same value for both systems. In addition, even though the surfactant system had a higher capillary number than the water system, wider surfactant fingers were observed. A possible mechanism explaining this is discussed by comparing with previous studies regarding VF with surfactants. The present study indicates that the capillary number does not control the nonlinear VF width in the surfactant system. Our results and discussion can be used to contribute to the establishment of well-controlled processes for surfactant flooding and the recovery of residual NAPL in aquifers.

Graphical abstractDisplay Omitted Plasma-assisted oxidation is preferable to form HfO2/GeOx/Ge structures.Al on HfO2/GeOx/Ge stack induces the reduction of GeOx and Al germanide formation.Hf germanide was formed in Pt/HfO2/GeOx/Ge stacks by annealing.Germanide formation should be suppressed for high-quality metal/high-k/Ge stack. We systematically investigated Ge diffusion and chemical bonding states in metal/high-k/Ge gate stacks by synchrotron radiation photoemission spectroscopy (SR-PES) to understand their impact on electrical properties. Although Hf germanide was found in both Ge 3s and Hf 4f spectra for HfO2/GeOx/Ge gate stacks formed by ultrathin metal Hf deposition and subsequent in situ low-pressure thermal oxidation, such germanide could be fully oxidized when using plasma-assisted oxidation. However, Al electrode deposition on HfO2/GeOx/Ge stacks was found to reduce interfacial GeOx layer, resulting in the formation of Al germanide at the Al/HfO2 interface even at room temperature. No germanide was formed in the stacks with inert Pt electrode. This indicates that the Al layer may promote upward diffusion of GeO molecules through the HfO2 layer. The thermal stability of metal/HfO2/GeOx/Ge gate stacks was also evaluated by in situ SR-PES. Hf germanide was observed to form near the HfO2/GeOx interface probably due to Ge atoms intermixing in the HfO2 layer in the Pt-gate stacks, in contrast to the enhanced formation of Al germanide in Al-gate stacks. Electrical characterization revealed that the formation of metal germanide led to severe degradation of insulating properties in metal/high-k/Ge stacks.

A 'guidance field' is a kind of a vector field that implicitly guides users to a target point. Users' input for travelling in virtual environments is slightly altered to get closer to the target directions according to the guidance field.

We, DAIHEN Corporation, have developed a real-time power and impedance sensor that enables real-time measurement of transmitted power and coil impedance in a kW class wireless power transfer during practical power transfer. Normally, accurate power measurement is assured only for characteristic impedance in which the reflected power is zero. However, the sensor we developed enables highly accurate measurement of power and load impedance at low impedance in practical applications besides characteristic impedance. This paper describes the calibration reference device and calibration method for highly accurate measurement, and measurement accuracy verification results.

In this paper, we propose Motive Compass, a new navigation interface for locomotion in virtual environment constructed with spherical images. In these virtual environments, users can gaze in all directions, but can only pass through lines where the camera has passed through during recording. Because the rotation of a virtual camera is not constrained to navigation paths, users may perceive that accessible locations are not constrained and they can freely move. Therefore, it is necessary to inform users of the accessible directions. Furthermore, velocity control is needed for close exploration in virtual environments. Therefore, we propose the Motive Compass input interface, which intuitively shows users the accessible directions and enables them to control the velocity. We conducted a large-scale demonstration experiment in a real exhibition to evaluate our interface and compared it with a conventional interface. The results show that our interface more effectively presents accessible directions and enables users to control their velocities, which supports the user's exploration in virtual environments.