Quadruple Phase Research Articles

Gallbladder fossa nodularity in the liver as observed in alcoholic liver disease patients: Analysis based on hepatobiliary phase signal intensity on gadoxetate-enhanced MRI and extracellular volume fraction calculated from routine CT data.

The purpose of this study is to further verify the concept utilizing signal intensity on hepatobiliary phase (HBP) of gadoxetate-enhanced MRI and extracellular volume fraction (ECV) calculated from CT data. Between Jan 2013 and September 2018, consecutive ALD patients who had both quadruple phase CT and gadoxetate-enhanced MRI within six months were retrospectively recruited. Those who had any intervention or disease involvement around gallbladder fossa were excluded. All images were reviewed and ECV was measured by two experienced radiologists. GBFN grades, and their HBP signal intensity or ECV relative to the surrounding background liver (BGL) were analyzed. There were 48 patients who met the inclusion criteria. There were GBFN grade 0/1/2/3 in 11/15/18/4 patients, respectively. The signal intensity on HBP relative to BGL were iso/slightly high/high in 30/15/3 patients, respectively, and ECV ratio (ECV of GBFN divided by that of BGL) was 0.88 ± 0.18, indicating there are more functioning hepatocytes and less fibrosis in GBFN than in BGL. The GBFN grades were significantly correlated to relative signal intensity at HBP (Spearman's rank correlation, p < 0.01, rho value 0.53), and ECV ratio (p < 0.01, rho value -0.45). Our results suggest GBFN in ALD would represent liver tissues with preserved liver function with less fibrosis, as compared to BGL, which are considered to support our hypothesis as shown above.

An Emergent Quadruple Phase Ensemble in Doped Bismuth Ferrite Thin Films Through Site and Strain Engineering

AbstractIn ferroic materials, giant susceptibilities can be realized at artificially constructed phase boundaries through deterministic manipulation of the order parameter. Here, emergent ferroelectric structural phase evolution behavior is demonstrated through a synergistic combination of A‐site doping and strain engineering. Using chemical solution deposition derived (001)‐oriented Sm‐substituted bismuth ferrite (Bi1‐xSmxFeO3) films as a prototypical system, a morphotropic phase boundary comprising a coexistence of four distinct crystallographic phases is uncovered. These ferroelectric, polar, and nonpolar phases form a nanoscale mixture without the presence of crystallographically hard boundaries. The system thus possesses the ability to show both polarization rotation and extension, effectively releasing the polarization from its crystallographic constraint. Consequently, both robust ferroelectric properties and giant electromechanical responses are obtained. For instance, the optimized composition with x = 0.14 has a remnant polarization of 2Pr = 103 µC cm−2 and electromechanical response 175% that of undoped BFO. These findings showcase the tremendous potential of synthetic phase boundaries, particularly in the context of lead‐free functional multiferroics.

Quadruple phase watermarking during high level synthesis for securing reusable hardware intellectual property cores

Reusable hardware intellectual property (IP) cores play a significant role in the modern system on chip (SoC) designs. However, raging threats of IP piracy and IP ownership infringement sabotage revenue and reputation of genuine IP vendors. This paper presents a novel quadruple phase watermarking for securing hardware IP cores during high level synthesis (HLS). The proposed approach introduces several novelties: graph partitioning, encoding tree, and eightfold mapping to generate a robust watermarking signature. Further, embedding signature during four phases of HLS viz. scheduling, register binding, resource binding and interconnect binding leads to a high-quality watermark. The proposed results indicate multiple times lower Pc and higher tamper tolerance than previous approaches, at negligible design cost overhead. We achieved improvements in Pc and tamper tolerance up to 1018 and 1052 times respectively than related works. Finally, security and design cost tradeoff for various signature strengths is presented.

Design of triple and quadruple phase boundaries and chemistries for environmental SO2 electrochemical sensing

Favorably engineering sensing reaction zones from triple phase boundaries to quadrupole phase boundaries towards enriching the functionality of the Li-garnet Li7La3Zr2O12 fast-conducting electrolyte for sensing applications beyond batteries.

Maximization of quadruple phase boundary for alkaline membrane fuel cell using non-stoichiometric α-MnO2 as cathode catalyst

Oxygen can only be reduced at the quadruple phase boundary (catalyst, carbon support, ionomer and oxygen) of the cathode catalyst layer with non-conducting electrocatalyst. To maximize the quadruple phase boundary sites is crucial to increase the peak power density of each membrane electrode assembly. The quadruple phase boundary is depending on the ratio of catalyst, carbon support and ionomer. The loading of catalyst layer is also crucial to the fuel cell performance. In this study, non-stoichiometric α-MnO2 manganese dioxide nanorod material has been synthesized and the ratios of carbon, ionomer and catalyst loadings were optimized in alkaline membrane fuel cell. In total, ten membrane electrode assemblies have been manufactured and tested. Taguchi design method has been applied in order to understand the effect of each parameter. The conclusion finds out the ionomer has more influence on the alkaline membrane fuel cell peak power performance than carbon and loading.

Diagnostic Performance of Quadruple Phase Multidetector Row Computed Tomography in Hepatoma: Comparison with Histopathological Diagnosis

Objective: To determine diagnostic accuracy of quadruple phase helical computed tomography scan in detection of hepatocellular carcinoma in individuals with hepatitis B and C, keeping histopathology as the gold standard. Methods: A cross-sectional study was performed in the Radiology and Imaging department of a tertiary care university hospital during 2014 to 2016. All serologically positive patients were included. Quadruple phase computed tomography scan was done and results were interrelated with histological diagnosis. Results: Hepatocellular carcinoma was accurately diagnosed in 76 out of 80 patients using Quadruple phase computed tomography scan (sensitivity, 95%). It was correctly excluded in 70 of 72 patients (specificity, 97.2%). The overall diagnostic accuracy of Quadruple phase computed tomography scan for diagnosing hepatocellular carcinoma was 96.05%. The positive and negative predictive values were 97.4% and 94.59% respectively. Conclusion: Quadruple phase computed tomography is more effective in evaluating hepatocellular carcinoma than conventional biphasic and triphasic computed tomography scans. We propose it as the technique of first preference for imaging workup in patients with Hepatitis B and C.

Motion capability analysis of a quadruped robot as a parallel manipulator

This paper presents the forward and inverse displacement analysis of a quadruped robot MANA as a parallel manipulator in quadruple stance phase, which is used to obtain the workspace and control the motion of the body. The robot MANA designed on the basis of the structure of quadruped mammal is able to not only walk and turn in the uneven terrain, but also accomplish various manipulating tasks as a parallel manipulator in quadruple stance phase. The latter will be the focus of this paper, however. For this purpose, the leg kinematics is primarily analyzed, which lays the foundation on the gait planning in terms of locomotion and body kinematics analysis as a parallel manipulator. When all four feet of the robot contact on the ground, by assuming there is no slipping at the feet, each contacting point is treated as a passive spherical joint and the kinematic model of parallel manipulator is established. The method for choosing six non-redundant actuated joints for the parallel manipulator from all twelve optional joints is elaborated. The inverse and forward displacement analysis of the parallel manipulator is carried out using the method of coordinate transformation. Finally, based on the inverse and forward kinematic model, two issues on obtaining the reachable workspace of parallel manipulator and planning the motion of the body are implemented and verified by ADAMS simulation.

A VCO-based phase-expanding conversion designed for time-domain data converters

This paper presents the design of a VCO-based phase-expanding converter (PEC) that converts a time residue to improve time resolution for the time-domain data converters. A voltage controlled oscillator, which has multiphase structure, is combined with the multi-layer delay chain to generate quadruple phases, and thus expands the overall resolution. Since the architecture of this converter is flexible for different designs, we propose a 6-bit, 250MHz PEC using a 16-phase, 1GHz VCO with quadruple phase expander in this paper. Simulations in a 0.18μm the CMOS process indicate that the PEC has DNL less than ±0.2LSB LSB, and INL less than ±0.3LSB. Furthermore, with the frequency variation from 0.9GHz to 1.1GHz, the PEC still has DNL ±0.21LSB, and INL ±0.29LSB. Experiment results show that the DNL is 0.52–0.13LSB and the INL is 0.21–0.66LSB.

Phase transformations in hypereutectic MgO-Y2O3 nanocomposites at 5.5 GPa

Hypereutectic 0.8MgO-0.2Y2O3 nanocomposites were studied using high pressure and high temperature in situ synchrotron energy dispersive x-ray diffractometry at 5.5 GPa and 1273 K. Polymorphic transformations in the Y2O3 phase, which resulted in a quadruple phase equilibria among cubic, hexagonal, and monoclinic phases with cubic MgO, were observed at 298 K under 5.5 GPa—a pressure much smaller than the pressures at which polymorphic transitions in macroscopic Y2O3. Time-resolved diffractometry at (1273 K, 5.5 GPa, 120 min) revealed a 0.87% expansive volumetric lattice strain in MgO, and is attributed to solid solution formation with Y2O3 which is otherwise absent at ambient conditions. The residual MgO unit cell volume expansion is 0.69% at 298 K, which is indicative that yttrium remained in solid solution. The macroscopic shrinkage due to densification at (1273 K, 5.5 GPa, 120 min) is 3.45% by volume. The partial molar volume of Y3+ in the solid solution is smaller than its molar volume in the pure state per thermodynamic considerations. The importance of repulsion among O2− ions in the immediate vicinity of a Mg2+ vacancy as well as misfit strain due to differences in ionic radii upon Y3+ substitution on Mg2+ sites is presented. A self-consistent model and explanation for the observed concomitant occurrence of cubic → monoclinic and cubic → hexagonal polymorphic transitions in Y2O3 and their stabilization at room temperature is proposed.

Determination of the upper-quadruple-phase equilibrium region for carbon dioxide and methane mixed gas hydrates

Abstract Simultaneous CO 2 sequestration and CH 4 production has been considered as a possible way to form and restore CO 2 hydrates in sediments of natural gas hydrates in seabeds. The phase equilibrium data for the upper-quadruple (H–W–L–V) phase states of CO 2 CH 4 mixed hydrates are needed for the application of the replacement of CH 4 hydrate with CO 2 . In this paper, the upper-quadruple (Q 2 ) phase equilibrium properties of CO 2 CH 4 mixed hydrates were investigated by using a visual experimental apparatus in the temperature range of 273.16–297.15 K and pressure up to 10 MPa and verified by calculation with thermodynamic models. The coexisting of upper-quadruple phase region was identified in 4.46–8.4 MPa, 283.09–287.9 K and 0–0.225 methane mole fractions. It is found that the range of temperature and pressure for Q 2 phase coexistence increases with the methane concentration until the retrograde of the quadruple phase is reached. The start and end melting points of the CO 2 CH 4 mixed hydrates in the upper quadruple states were tested in constant volume condition. The tested results had also been compared with the predictions with a combination of the thermodynamic models for the mixed gas hydrate and CO 2 CH 4 vapor–liquid equilibrium. The existence of the Q 2 phase equilibrium region and its extension are clarified.

Using low tube voltage (80kVp) quadruple phase liver CT for the detection of hepatocellular carcinoma: Two-year experience and comparison with Gd-EOB-DTPA enhanced liver MRI

To validate the diagnostic performance of quadruple phase low tube voltage liver CT through the comparison with Gd-EOB-DTPA enhanced liver MRI for the detection of HCC. Non-obese patients (38 men, eight women) with 68 HCCs underwent quadruple-phase CT at 16 MDCT (using low tube voltage, 80kVp; moderately high tube current, 280mAs) and Gd-EOB-DTPA-enhanced 3T MRI. Three observers independently and randomly reviewed the CT and MR images on a tumor-by-tumor basis. The diagnostic accuracy of these techniques for detecting HCC was assessed using alternative free-response receiver operating characteristic analysis. Sensitivity and positive predictive values were evaluated. The mean effective doses for the low dose CT were also evaluated. The areas under the ROC curves were 0.963, 0.959, and 0.941 for low dose CT and 0.981, 0.982, and 0.976 for MRI. Differences in Az of the two techniques for each observer were not statistically significant (P>.05). Differences in sensitivity and positive predictive values between the two techniques for each observer were not also statistically significant: sensitivity (86.8%, 82.4%, 85.3% for CT and 95.6%, 94.1%, 91.2% for MRI) and positive predictive values (92.2%, 90.3%, 89.2% for CT and 92.9%, 92.8%, 92.5% for MRI). Six HCCs (8.8%) in five patients were observed only on hepatobiliary phase of MRI, and all were smaller than 1.5cm. The mean effective dose for CT was approximately 10.2mSv. Quadruple-phase low-dose liver CT (80kVp, 280mAs) had relatively good diagnostic performance for detecting HCC in non-obese patients. Because no significant difference was observed between low-dose CT and MRI, the use of low-dose liver CT can be justified based on its reduced radiation effects.

Experimental Determination of the Equilibrium Conditions of Binary Gas Hydrates of Cyclopentane + Oxygen, Cyclopentane + Nitrogen, and Cyclopentane + Hydrogen

In this work, four-phase hydrate equilibrium data for each of the systems cyclopentane (CP) + water + hydrogen, CP + water + nitrogen, and CP + water + oxygen were measured and are reported in the temperature range of 281.3−303.1 K and the pressure range of 2.27−30.40 MPa. Measurements were made using an isochoric method. Experimental data on the equilibrium conditions of the two systems nitrogen + water and hydrogen + water with CP are reported over a previously uninvestigated extended temperature span. The hydrate dissociation data for the CP + water + hydrogen system are compared with some selected experimental data from the literature, and the acceptable agreement demonstrates the reliability of the experimental method used in this work. Finally, the first quadruple phase equilibrium data in the ternary system CP + water + oxygen have been achieved.

SIZE-INDUCED PHASE TRANSITION IN BaTiO3 NANOCERAMICS DESCRIBED BY NANO-DOMAINS AND LONG-RANGE INTERACTION

The size effect of nano-grain BaTiO 3 ceramics has been studied in this paper. We assume that the surface charge does not fully compensate long-range Coulomb interaction, so that 180 degree nano-domains still exists in small BaTiO 3 particles. We have calculated the long-range interaction in BaTiO 3 nanocrystals with 180 degree nano-domains, and obtained the relationship between grain size and domain size. The relation between transition temperature and grain size is also obtained by incorporating the domain-wall energy into the Landau–Ginzburg free-energy density. The results show that with decreasing grain size the transition temperature of cubic-tetragonal phase decreases, while those of tetragonal-orthorhombic and orthorhombic-rhombohedral phases increase. Our model predicts that with further reduction of grain size, the structures of ferroelectric phase becomes unstable and gradually disappears, leaving only one stable structure of cubic phase. In addition, an interesting conclusion is that a quadruple phase point exists in the phase diagram of the transition temperature versus grain size. The results are compared with experimental data.

Terahertz CMOS Frequency Generator Using Linear Superposition Technique

A low Terahertz (324 GHz) frequency generator is realized in 90 nm CMOS by linearly superimposing quadruple (N=4) phase shifted fundamental signals at one fourth of the output frequency (81 GHz). The developed technique minimizes the fundamental, second and third order harmonics without extra filtering and results in a high fundamental-to-4 th harmonic signal conversion ratio of 0.17 or -15.4 dB. The demonstrated prototype produces a calibrated -46 dBm output power when biased at 1 V and 12 mA with 4 GHz tuning range and extrapolated phase noise of -91 dBc/Hz at 10 MHz frequency offset. The linear superposition (LS) technique can be generalized for all even number cases (N=2k, where k=1,2,3,4,...,n) with different tradeoffs in output power and frequency. As CMOS continues to scale, we anticipate the LS N=4 VCO to generate signals beyond 2 Terahertz by using 22 nm CMOS and produce output power up to -1.5 dBm with 1.7% power added efficiency with an LS VCO + Class-B Power Amplifier cascaded circuit architecture.

Effect of Pressure on Magnetic States of Easy-Plane Antiferromagnets

The phase II —P—$ diagram of an easy-plane strongly anisotropic antiferromagnet is studied. It is shown that in such a system a realization of the phase with the nonmagnetic order parameter, the so-called quadruple phase, is possible. The realization of this phase is caused by several purely quantum effects, moreover the mechanism of its appearance differs in principle from that of the antiferromagnet or ferromagnet. The possibility of the disappearance of the angular phase (the so-called quadruple ferromagnetic phase) is also shown.

Strong Non-Linear MCD-Effects Due to Partially Circular Polarized Light Sources

ABSTRACTMost soft x-ray magnetic dichroism studies are carried out with light of mixed polarization. The effect of incomplete circular polarization is usually taken care off by linearly extrapolating the data to Pcirc=l. Using a classical model which includes the polarization factor we show that the MCD-effect, which is the normalized quantity 2(I+-I-)/(I++I-), is highly non-linear with regard to cire. With a specially designed quadruple reflection phase shifter we measured the MCD effect with Pcire&lt;l as well as with Pcirc∼1. MCD spectra of Fe around the M2,3 transition verify our model calculations of the polarization dependence. The data indicate that the observed non-linear response of the MCD-effect to Pcirc can generally introduce large errors in the quantitative analysis of MCD data where spin &lt;Sz&gt; and orbital &lt;LZ&gt; moments are extracted by means of sum rules.