Proton incorporation in yttria-stabilized zirconia during atomic layer deposition

This work elucidated the proton-incorporation mechanism in ALD YSZ¹. Isotope ²H₂O was used as an oxidant to trace proton incorporation. The ratio of ZrO₂ to Y₂O₃ ALD cycles was varied from 1:1 to 5:1. TEM confirmed that the ALD YSZ films grew as fully crystallized columnar grains in the cubic ZrO₂ phase. SIMS indicated that the Y³⁺ and ²H⁺ concentrations were linearly correlated, indicating yttria-deposition-induced proton incorporation. XPS confirmed an appreciable amount of Y(OH)₃ proportional to the ²H⁺ content in the ALD YSZ, as was also detected by SIMS. Oxide ion vacancies created by the replacement of ZrO₂ with relatively small amounts of Y₂O₃ provided additional vacancies for proton incorporation, resulting in steeper [²H⁺]/[Y³⁺] slopes.     

Selective Raman Scattering Detection of the Dirac Node and the Anti-node of the Spin Density Wave Gap and Magnetic Excitations in BaFe2As2

The electronic and magnetic excitations at the spin density wave (SDW) transition are investigated by Raman scattering. The multi-orbital electronic states induce the Dirac nodes in the SDW gap. The excitations near the nodes and anti-nodes are separately detected in accordance with the two-orbital tight-binding model. The exchange interactions are found to be given by the second derivative of the total energy with respect to the angle of the moment from two-magnon scattering. The two-magnon peak has the large spectral weight above twice the maximum energy of magnon. It is interpreted by the magnetic self-energy of the electron spectral function in the localized spin model or particle-hole excitations in the itinerant spin model.     

Flow condensation heat transfer coefficients of R22, R134a, R407C, and R410A inside plain and microfin tubes

Flow condensation heat transfer coefficients (HTCs) of R22, R134a, R407C, and R410A inside horizontal plain and microfin tubes of 9.52 mm outside diameter and 1 m length were measured at the condensation temperature of 40 °C with mass fluxes of 100, 200, and 300 kg m⁻² s⁻¹ and a heat flux of 7.7–7.9 kW m⁻². For a plain tube, HTCs of R134a and R410A were similar to those of R22 while HTCs of R407C are 11–15% lower than those of R22. For a microfin tube, HTCs of R134a were similar to those of R22 while HTCs of R407C and R410A were 23–53% and 10–21% lower than those of R22. For a plain tube, our correlation agreed well with the present data for all refrigerants exhibiting a mean deviation of 11.6%. Finally, HTCs of a microfin tube were 2–3 times higher than those of a plain tube and the heat transfer enhancement factor decreased as the mass flux increased for all refrigerants tested.     

Low-complexity two-step lossless depth coding using coarse Lossy coding

Texture and depth images are generally used for 3D viewing with advanced displays. Because sthe characteristics of a depth image are very different from those of a texture image, an efficient compression method is required to transmit a depth image in a limited bandwidth. In this paper, a low-complexity two-step lossless depth coding (LTLDC) method using coarse lossy coding is proposed. The proposed method downsamples an original image and then coarsely compresses the downsampled image in the first step. This compressed image is upsampled, and then its residual is generated by subtracting the upsampled image from the original image. In the second step, each coding block within the residual and original images is adaptively compressed with a fast mode decision method in a lossless way, and the proposed method determines the best block based on their coding performance. Experimental results show that the proposed LTLDC method achieves a bitrate reduction of 4.35% with encoding complexity reduction of 20.38%.

     

Pt-Al2O3 Cryogel with High Thermal Stability for Catalytic Combustion

The cryogel catalyst of platinum on alumina was prepared from aluminum sec-butoxide and H₂PtCl₆ through the sol-gel technique and subsequent freeze drying. The cryogel catalyst showed higher thermal stability of platinum than the corresponding xerogel or impregnation catalysts, which was ascribed to the more intimately developed platinum-alumina interaction accompanied by the encapsulation of the metal into the alumina cryogel. It was also shown that platinum accessibility was higher on the cryogel than on the xerogel despite the higher thermal stability of the metal on the formed than on the latter. For the VOC combustion, the cryogel exhibited higher activity than the xerogel and impregnation catalysts. Also for the methane combustion the cryogel showed higher activity, although it showed lower activity than the impregnation catalysts above 600 °C. By the addition of ceria as an additive to the cryogel catalyst, the CH₄ combustion activity was improved especially in the temperature region above 600 °C.     

Effect of pressure drop on performance of hollow-fiber membrane module for gas permeation

The pressure drop mainly due to viscous friction inside hollow fibers is taken into consideration by nondimensionalization and numerical simulation of governing equations. For pure gas, the permeation pressure and velocity of actual situations with a viscous fluid deviate significantly from those of the corresponding inviscid or no-pressure-drop cases. The apparent permeability estimated from the relation of permeate flow rate and pressure difference is considerably underestimated in actual situations, and more severely for the region of small pressure difference and large module length. Numerical simulation shows that the estimated permeability behaves as if it were an increasing function of pressure difference for a constant permeability and roughly a constant for a dual-sorption-type permeability, respectively. For binary-mixture permeation the cut ratio and purity of permeate stream are mainly governed by two dimensionless parameters standing for pressure drop and permeability, respectively. The cut ratio and corresponding product composition are predictable without the rigorous simulation of the governing equations.     

Thermal properties of Y(BH4)3 synthesized via two different methods

Y(BH₄)₃ is one of the candidates for solid-state hydrogen storage, which contains 9.06 wt% of hydrogen. In this study, the thermal properties of Y(BH₄)₃ synthesized via two different methods are extensively examined. One method relies on the solid–solid metathesis reaction between LiBH₄ and YCl₃, and the other method is the gas–solid reaction between B₂H₆ and YH₃. The two samples are studied by differential scanning calorimetry, thermogravimetry, and X-ray diffraction. They exhibit distinctly different polymorphic phase transformation and melting. It turns out that the side product LiCl in the metathesis reaction, which has been regarded as being inert, shifts the melting point and promotes the formation of YB₄ during decomposition. Differential scanning calorimetry and in situ X-ray diffraction data indicate that the addition of LiBH₄ to Y(BH₄)₃ induces co-melting as is found in the cases of LiBH₄–Ca(BH₄)₂ or LiBH₄–Mg(BH₄)₂. Melt infiltration of Y(BH₄)₃ into mesoporous carbon cage confirms such melting behavior.     

Hyperparathyroidism caused by distant pulmonary lesions and parathyromatosis after ethanol injection/parathyroidectomy for secondary hyperparathyroidism

Secondary hyperparathyroidism (SHPT) treatment includes parathyroidectomy and percutaneous ethanol injection therapy (PEIT), which are invasive procedures. The condition in which benign hyperfunctioning parathyroid tissue is distributed throughout the neck and mediastinum is termed parathyromatosis. Here, we present the case of a 51‐year‐old woman who began hemodialysis in 1986 due to chronic kidney disease of unknown etiology and developed SHPT in 1999. She underwent 6 rounds of PEIT followed by total a parathyroidectomy with partial forearm autotransplantation. Between 2011 and 2013, surgeons removed several nodules from her pulmonary and cervical regions and the transplanted masses from her forearm; all showed hyperplasia but exhibited no histological evidence of malignancy. Damage to the parathyroid capsule after repeated PEITs may cause local cervical recurrence and pulmonary lesions, although distant lesions are extremely rare in SHPT. This case is of interest due to the possible association between PEIT and parathyromatosis and distal lesions.     

Incorporating macroeconomic feedback into an energy systems model using an IO approach: Evaluating the rebound effect in the Korean electricity system

This paper approximates the emissions rebound effects¹ associated with substituting expensive and GHG emitting natural gas (LNG) power plants, with apparently cheaper and lower emitting nuclear plant. It then evaluates the effect this has on economy wide electricity use as well as net GHG emissions changes.