Sudden Change In Slope Research Articles

CI-452766-1 ABRUPT TORQUE TRANSFER OCCURS FREQUENTLY DURING CONDUCTION SYSTEM PACING INSERTION IN AN EX-VIVO MODEL

A fundamental challenge in conduction system pacing [CSP] is determining appropriate lead deployment. With either fixed core or stylet driven leads, the input number of turns may not match resultant rotations achieved by the helix. To date, no validated ex-vivo experimental model has been developed to enable quantitative assessment of the ratio of input turns to helix rotation. To develop a model system to quantitatively describe CSP lead tip to tissue response curves. Sixty-four fresh (<48h) ex-vivo ovine right ventricular septa were excised. Four different leads (1 fixed core (A), 3 stylet-driven (B,C,D)) were driven into the septal myocardium using support via a custom-engineered jig allowing control of input rotation and measurement of helix rotation. Leads were inserted using 15 turns applied proximally on the lead, with resultant helix rotation and tissue-interface characteristics observed at each 90° increment via high resolution photography. Output (helix) rotation vs input rotation response curves [RRC] were assessed using automated segmented linear regression. RRC linear models were statistically analysed using slope (to characterise input vs output response) and breakpoints (to characterise abrupt torque transfer [AAT]). A total of 3840 observations of ¼ turn at the proximal CSP lead were recorded. 16 repeated RRCs were created for each lead type. Mean input vs output slope across leads was 0.46 [95%CI 0.39, 0.52] implying muted output rotations compared to input rotations. Mean number of abrupt torque transfer events [ATT] during each 15 turn insertion (measured by linear break-points in RRC) was 7.2 [95%CI 6.6, 7.7]. In 57.8% (37/64) of lead insertions, there were uncontrolled abrupt torque transfer events [uATT] where the output response at the lead tip was more than the input rotation. An ex-vivo model system was created to examine the torque transfer relationship for CSP leads. Using a robust sample size, this model showed the relationship between input turns yields an overall muted response at the lead tip. However, during insertion, abrupt torque transfer events are common, with uncontrolled abrupt torque transfer events occurring during more than half the insertions. These findings are of clinical significance to CSP implanters to be aware of the potential abrupt torque transfer events, particularly when they are uncontrolled. These data suggest new lead designs may be required to increase the efficiency and safety of CSP.Tabled 1Slope and breakpoint analysis of rotation relationship curves.Lead TypeLead TypeMean RRC Slope [95%CI]Mean # ATT events per insertion [95%CI]Mean # uATT events per insertion [Range]Solid CoreLead A0.28 [0.15, 0.55]7.31 [6.08, 8.54]0.5 [0 to 3]Stylet DrivenLead B0.48 [0.37, 0.71]6.81 [5.57, 8.05]0.69 [ 0 to 3]Stylet DrivenLead C0.66 [0.55, 0.88]7.56 [6.50, 8.62]1.31 [ 0 to 6]Stylet DrivenLead D0.45 [0.35, 0.64]7.18 [6.11, 8.26]0.86 [ 0 to 2]ALL0.46 [0.39, 0.52]7.22 [6.08, 8.35]0.84 [0 to 6]Table 1: Slope and breakpoint analysis of rotation response curves shows that the output rotations delivered to the helix are substantially less than the input rotations. Abrupt torque transfer events occur when sudden changes in the rotations delivered at the helix are observed, and occur frequenty during 15 rotation insertion of physiological pacing leads. Uncontrolled abrupt torque transmission at the helix occurs when the helix rotation exceeds the immediate input rotation, indicating a sudden release of torque build-up from the lead. RRC = Rotation Response Curve. ATT = Abrupt Torque Transfer event where sudden change in slope of RRC. uATT = Uncontrolled Abrupt Torque Transfer Events where Helix rotation > input rotation. Open table in a new tab

Carburization depth evaluation from magnetic nondestructive testing

Precise estimation of carburization depth is mandatory to avoid failure and critical degradation of high-performance mechanical parts. In this work, we studied magnetic methods as an indirect way to obtain this information. Usual techniques consisting of complex combinations of unrelated indicators have been left aside and replaced by a theoretical approach based on the magnetization mechanisms.A series of rod specimens were pre-characterized using destructive hardness tests and classified into four categories from virgin to very deep carburization depth. Then, rods from each batch were tested with different magnetic testing techniques. Identical experimental conditions were kept to limit the degrees of freedom and ensure the viability of the conclusions. The Magnetic Incremental Permeability (MIP) maximal amplitude ΔZ which is associated with the domain wall bulging mechanism showed the highest linear correlation with the carburization depth.Based on these first observations, new experimental conditions were proposed: MIP AC component frequency was reduced to 1 kHz, leading to a magnetic penetration large enough to reach the specimen core. A sudden change in slope was observed on the MIP signature of the treated specimens when the excitation field was close to the core coercivity (of similar magnetic behavior as untreated specimens). The corresponding local slope obtained a very high 0.987 linear correlation coefficient vs. carburization depth and revealed low-frequency MIP as an effective magnetic nondestructive technique for thick carburization evaluation.

Electron-phonon coupling origin of the graphene π* -band kink via isotope effect

The ${\ensuremath{\pi}}^{*}$-band renormalization of Li-doped quasifreestanding graphene has been investigated by means of isotope ($^{13}\mathrm{C}$) substitution and angle-resolved photoemission spectroscopy. The well documented sudden slope change (known as ``kink'') located at 169 meV from the Fermi level in the graphene made of $^{12}\mathrm{C}$ atoms shifts to 162 meV once the carbon monolayer is composed by $^{13}\mathrm{C}$ isotope. Such an energy shift is in excellent agreement with the expected softening of the phonon energy distribution due to the isotope substitution and provides, therefore, an indisputable experimental proof of the electron-phonon coupling origin of this well known many-body feature in the electronic structure of graphene.

Use of UAV-Photogrammetry for Quasi-Vertical Wall Surveying

In this study, an analysis of the capabilities of unmanned aerial vehicle (UAV) photogrammetry to obtain point clouds from areas with a near-vertical inclination was carried out. For this purpose, 18 different combinations were proposed, varying the number of ground control points (GCPs), the adequacy (or not) of the distribution of GCPs, and the orientation of the photographs (nadir and oblique). The results have shown that under certain conditions, the accuracy achieved was similar to those obtained by a terrestrial laser scanner (TLS). For this reason, it is necessary to increase the number of GCPs as much as possible in order to cover a whole study area. In the event that this is not possible, the inclusion of oblique photography ostensibly improves results; therefore, it is always advisable since they also improve the geometric descriptions of break lines or sudden changes in slope. In this sense, UAVs seem to be a more economic substitute compared to TLS for vertical wall surveying.

Hummocky terrain of the Kalibabak debris avalanche deposit, Lombok Island, Indonesia

The debris avalanche deposit (DAD) coverage can drastically modify the surrounding landscape of volcanoes. DAD can be distinguished by hummocky irregular surface, jigsaw fissure, and mixing horse-shoe shape. Due to its particular shape of a hummock, the topography can be easily identified using DEM (Digital Elevation Model) and satellite imagery. The aim of this study is to characterize hummocky terrain in Lombok Island, which is located in the Kalibabak formation on the Geological map through the geomorphic approach. Hummocky terrain in this study are analyzed using DEM data from DEMNAS (DEM Nasional: 0.27-arcsecond resolution). Our study of this DAD encompasses seven variables, namely H/L ratio, numbers hummocks, distance to source, slope, area (size), relative height, topographic section, and hummock-spreading shape. A minimum of 756 hills derived from this DEM are considered as hummocks from this DAD, which extends ~18 km (NS) and ~25 km (WE) in the central part of Lombok Island. With an area of ~200 km2 and a volume estimated around 8.8 km3, the Kalibabak DAD is more than three times larger than the one of the Mount St-Helens in 1980. The morphology of hummocky terrain is bounded by a sudden change of slope, which is indicated by a river confluence. Average hummock size is 2.7 ha and average distance between each hummock is 150 m to 300 m. The hummocks are characterized by steep slopes (25 % to 45 %) at the boundary to colluvium plain (debris deposit), which makes them easy to identify using DEM. Hummocks spreading distribution forms a conical-like shape with a H/L ratio of 0.13. The spreading distribution shape, the H/L and V/L ratios are useful as an input for reconstructing the mechanism of debris avalanche emplacement.

Speed of domain walls in thin nanotubes: The transition from the linear to the magnonic regime

Numerical simulations of domain wall propagation in thin nanotubes when an external magnetic field is applied along the nanotube axis have shown an unexpected behavior described as a transition from a linear to a magnonic regime. As the applied magnetic field increases, the initial regime of linear growth of the speed with the field is followed by a sudden change in slope accompanied by the emission of spin waves. In this work an analytical formula for the speed of the domain wall that explains this behavior is derived by means of an asymptotic study of the Landau Lifshitz Gilbert equation for thin nanotubes. We show that the dynamics can be reduced to a one dimensional hyperbolic reaction diffusion equation, namely, the damped double Sine Gordon equation, which shows the transition to the magnonic regime as the domain wall speed approaches the speed of spin waves. This equation has been previously found to describe domain wall propagation in weak ferromagnets with the mobility proportional to the Dzyaloshinskii-Moriya interaction constant, for Permalloy nanotubes the mobility is proportional to the nanotube radius.

Factors predictive of roof instability in addition to the existing CMRR criteria at two case study coal mines

This work uses two underground longwall coal mines located in the Western US (Mines A and B) as case studies to investigate which parameters are indicative of roof fall potential, and whether the Coal Mine Roof Rating (CMRR) is predictive of stability at these mines. Data were collected at 30 sites in each mine. These data sets included the CMRR, a record of the roof stability and a series of non-CMRR parameters thought to also be potentially indicative of roof stability but which are not included in the CMRR. These data were then statistically analyzed for correlation between CMRR and roof stability. The CMRR was found to be moderately effective at Mine A but not effective at Mine B. At Mine A, faulting was found to be the primary control on roof stability. Topographic curvature, slope angle and depth of cover were found to have reasonable predictive capability for assessment of roof stability category at Mine B based on a logistic regression analysis.These differences in roof stability controls are likely due, at least in part, to the unusual topography above Mine B, with differential erosion resulting in a landscape of flat plateaus and sharp river valleys. It is likely that these sudden changes in slope and topography lead to in-situ stress rotation and the development of shear stresses near the excavation at Mine B. This, combined with a lack of major discontinuities such as slickensides, which are central to the CMRR system, explains why the CMRR is much less effective at predicting roof stability at Mine B compared to Mine A.

An ArcGIS Model for Avalanche Risk Assessment in the North Cascades, Washington

ABSTRACTReports of avalanche-related deaths have increased over the last fifty years in the United States. Although incidents occurring in Washington State and in the North Cascades do not reflect the bulk of avalanche-related casualties in the United States, it remains an annual concern for both recreational safety and transportation. This research seeks to apply and update methods from previous studies to evaluate avalanche risk in the North Cascades. Hazardous areas are identified by naturally occurring avalanche trigger zones. This study involves a mixed-method analysis using predefined geomorphic conditions, such as constant slope and sudden slope change, as well vegetation density, to identify natural avalanche trigger zones using ArcGIS. The outcome of the hazard assessment model is then evaluated using coordinates for reported avalanche debris sites and imagery interpretation. The postprocess evaluation also uses onsite ground photos of avalanche debris, captured by skiers, that help further assess how accurately the geographic information systems process is able to depict high-risk avalanche zones. A non-region-specific tool was produced in the form of an ArcGIS model that can be used to evaluate the avalanche hazard criteria in any regional area of interest.

Simulation on Release Characteristics of the Gas Extinguishing Agent in Fire Extinguisher Vessel with Different Filling Conditions Based on AMESim

Abstract To study the release characteristics of the gas extinguishing agent from fire extinguisher vessel at different filling conditions, a gas fire extinguishing agent jet test platform was established. The calculation model of jetting gas extinguishing agent from gas extinguisher vessel was constructed with AMESim and the jet performance of gas extinguishing agent was simulated by using the two-phase flow model. By changing the initial temperature and filling pressure, the pressure changed at the outlet of the vessel is simulated, and then the change of the outlet pressure and the discharge time were analyzed emphatically. The results showed that the outlet pressures of the fire extinguisher vessel had the same trend basically at different initial temperature; all of them declined rapidly with the jetting time and then tended to be gentle. When the filling pressure was lower, the outlet pressure of the vessel at different initial temperature was quite various, and the sudden slope change could be seen obviously during the discharge process at higher initial temperature. When the initial temperature ranged from -30 ℃ to 30 ℃, the jetting time shortened with the rising of the initial temperature at different filling pressure. In addition, the outlet pressure of the fire extinguisher vessel tended to be flat with the rapid decrease in the injection time. At different filling pressures, the outlet pressure of the vessel declined rapidly with the jetting time and then tended to be gentle.

Optical characterization of mechanically alloyed PbSnS3 nanocrystals

The present study explains the preparation of PbSnS3 nanocrystals using mechanical alloying as the processing technique and elemental powders as the starting material. The elemental powders of Pb, Sn and sublimed sulphur (S) were mechanically alloyed for 40h. Phases evolved during mechanical alloying are explored by X-ray diffraction (XRD). The morphology and microstructural features have been investigated using High-resolution Transmission Electron Microscopy (HRTEM). UV–Vis–NIR spectroscopy has been used to measure the optical absorption characteristics. The mechanically alloyed powders show particle sizes in the range of 3–12nm. The absorption edge extends from 503nm to the visible region to 1360nm near infrared region with a sudden change in slope at 860nm, indicating the feature of indirect band gap semiconductors. The intersection point with the x-axis of extrapolating (αE)2 line as a function of E gives a direct band gap of 1.33eV and an indirect gap of 0.59eV.

An ISOBUS-Networked Electronic Self-Leveling Controller for the Front-End Loader of an Agricultural Tractor

Abstract. There has been a growing trend toward electronic control of hydraulic systems in agricultural machinery to improve operator comfort. Rapid advances in information and communications technology and the expansion of agricultural attachments have led to the introduction of control systems following the ISOBUS standard. Feedback control of a front-end loader (FEL) using electro-hydraulic proportional valves and sensors allows automatic activation of the boom and bucket cylinders and repetitive operational sequences of FEL functions. The mechanical self-leveling systems commonly used to prevent rollback have a limited range of operation and provide overcompensation beyond that range, therefore requiring considerable driver attention when operating the FEL. This article describes the development and evaluation of an ISOBUS-networked electronic self-leveling system that uses three electronic control units (ECUs), i.e., loader, joystick, and virtual terminal ECUs, to automatically adjust the orientation of the loader bucket with respect to the ground based on real-time measurements of bucket angle and angular velocity. Key improvements to the system, compared to a previous study that developed a proportional and integral (PI)–based self-leveling controller include the addition of a velocity feedback element and a dead-time effect computation to the control loop. An embedded electronic controller was implemented on agricultural tractors to test its ability to maintain the desired bucket angle regardless of varying ground slopes or the lifting or lowering motion of the boom. In laboratory testing with a FEL simulator, the use of the velocity feedback loop enabled the bucket angles to reach reference angles of +20°, showing reductions in rise times from 0.75 to 0.51 s and from 0.84 to 0.39 s on ascending and descending slopes, respectively, compared to the PI-based self-leveling algorithm. At a traveling velocity of 2.5 km/h, there was little change in bucket angle, with an almost constant level of &amp;lt;1°. However, at a velocity of 7.5 km/h, inflection points on the paved road caused relatively large deviations from the reference angle ranging from 3° to 5°, thus requiring the use of a look-ahead method to predict sudden changes in slope using a LIDAR sensor that can characterize the ground surface. In an outdoor bench test using a joystick to raise and lower the boom of a FEL, the self-leveling algorithm allowed the bucket angle to be maintained at the desired level, with RMSEs of 2.1±0.65° and 3.4±0.81° in the raising and lowering modes, respectively; thus, it could be implemented in an electronic self-leveling system for a FEL, which could then be employed in an ISOBUS-networked tractor offering the potential to eliminate the possibility of load rollback. Keywords: Dead-time computation, Electro-hydraulic proportional valve, Electronic control unit, Front-end loader, ISOBUS, Self-leveling, Velocity feedback.

Two different technical criteria for determining the minimum miscibility pressures (MMPs) from the slim-tube and coreflood tests

In this paper, two different technical criteria, i.e., the oil recovery factor (ORF) and break-over pressure (BOP), are studied and compared to determine the minimum miscibility pressures (MMPs) of two light crude oil–CO2 systems. More specifically, five slim-tube tests with the live light crude oil–CO2 system and five coreflood tests with the dead light crude oil–CO2 system are conducted to measure the ORFs at different injection pressures and the actual reservoir temperature of Tres=53.0°C. The linear and quadratic extrapolation methods as well as the linear intersection method are applied by using the ORF criterion. Three different high threshold ORFs of 88% for the slim-tube tests or 87% for the coreflood tests, 90% and 95% are chosen to determine the MMPs by means of the linear and quadratic extrapolation methods. On the other hand, the linear intersection method is used to determine the MMP by finding a sudden slope change point in the measured ORF versus injection pressure curve for the slim-tube or coreflood tests. Moreover, the BOP criterion is based on the cubic regression of the measured ORF versus injection pressure data and used to determine the MMPs, which correspond to four different low threshold slopes or incremental ORFs per incremental injection pressure increase of 5, 3, 2, and 1%/MPa. It is found that different MMP ranges can be obtained from the same measured ORF versus injection pressure data if different MMP criteria, regression methods, and threshold values or numerical options are adopted. The determined MMP is better given in a small pressure range than specified as a definitive pressure value. Two MMP ranges of the live and dead light crude oil–CO2 systems are determined to be 15.2–15.4MPa and 12.4–12.9MPa at Tres=53.0°C, respectively.

Statistical investigation on the power-law behavior of magnetic fluctuations in the Venusian magnetosheath

The present work aims to develop a better understanding of wave and turbulence processes in the planetary magnetosheath region. We study the plasma conditions (temperature, flow velocity, and magnetic field), the low-frequency wave properties, and the energy spectra for magnetic field fluctuations in the Venus magnetosheath. We use the magnetic field data of 101 magnetosheath flank crossings from the Venus Express magnetometer experiment in the years 2006 and 2008. The statistical investigation of the plasma conditions shows that the mean magnetic field amplitude is about 10 nT, the average proton temperature of the order of MK, and the super-Alfvenic, subsonic bulk plasma flow. Below 0.07 Hz, the angle of propagation is about 80° for the most of the cases, and it varies from 10° to 90° above the frequency 0.07 Hz. The compressibility shows similar distribution at low (below 0.07 Hz) and high frequencies (above 0.07 Hz). The energy spectra in the spacecraft frequency frame reveal the power-law behaviors which give physical insight on the energy transfer from larger to smaller scales due to wave–wave interaction. A spectral break (sudden change in slope) is observed at 0.25 Hz, above which the spectral curve becomes steeper with spectral indices between −4 and −1.5 (close to the Kolmogorov slope, −5/3). The low-frequency part (below 0.07 Hz) having a spectral index close to −1 indicates the energy cascades due to mirror mode waves, and the steepen spectra at high frequencies (above 0.07 Hz) with spectral indices between −4 and −0.5 are interpreted as the energy accumulation due to mirror mode and proton cyclotron waves.

The Effect of Particle Size on The Migration Rate of Knickpoint Erosion at Different Hydraulic Conditions

Abstract. Knickpoint, gully or head cut is called the erosion that is formed because of the sudden change in water level or bed level in the river and after concentrating the flow lines the local shear stress increase, bring about the bed erosion rate be intensified in a location where sudden change bed takes place. This erosion causes the riverbed in the location of sudden slope change to migrate to the upstream and makes the width of the river change. This erosion creates irreparable damages. Destruction of upstream structures caused by the bed migration and also roads destruction, residential areas, tourism - recreational areas, farmlands and good vegetation cover can be mentioned. In this paper, we have studied the effect of particle size and various hydraulic conditions to the rate of Knickpoint erosion progression. In this paper to create the relations of migration rate to the upstream according to the hydraulic parameters a laboratory hydraulic flume with dimensions 3 meters in length, width 30cm and height 50 cm was used. The main purpose of the paper is to creating relations for predicting the rate of Knickpoint erosion rates increase in the non-cohesive soil.

Numerical study of turbulent wall jet over multiple-inclined flat surface

In the present work flow field of a turbulent oblique wall jet with multiple flat inclined wall has been numerically investigated. The Reynolds averaged Navier–Stokes (RANS) equations for incompressible flow are solved in transformed geometry using boundary-fitted coordinate system. The aim of the work is to investigate the influence of three inlet conditions: uniform, parabolic and trapezoidal inlet velocity profiles, on the mean flow and turbulent characteristics of the jet flowing tangentially along a multiple inclined solid wall. The results show that the inlet conditions affect the flow in the vicinity of the nozzle exit area and also the far field region. Mean flow has been presented in terms of evolution of mean velocity profiles, jet spread, decay of streamwise maximum velocity, distribution of wall pressure and skin friction coefficients, and streamwise variations of integrated momentum and energy fluxes. Discontinuities in the boundary slope of the segmented wall produces oscillations in distribution of skin friction and pressure coefficients. Reduced pressure in the region of wall discontinuity appeared to be causing the deflected jet to remain attached to the wall. The growth of the inner layer of the jet is relatively high with uniform inlet velocity profiles in the near-field region, but in the far-field region the inner layer grows with higher rate for the trapezoidal and the parabolic profiles. The rate of decay of maximum streamwise velocity for oblique wall jet on segmented wall is higher than that of plane wall jet. The jet with parabolic and trapezoidal inlet profiles show higher rate of decay than that with a uniform inlet profile. Similarity of streamwise velocity and velocity component parallel to the oblique wall has been observed in the developed region of flow. The volume flow rate of the jet varies linearly along the flow direction due to entrainment of the fluid from the surrounding. Sudden change in slope of the wall causes a sharp rise in entrained volume of fluid. The distribution of near wall velocity in the inner coordinates of the boundary layer is grossly altered and the profiles do not conform to the universal velocity profiles in the form of the law of the wall. Relatively higher position of defect law data signifies comparatively lower turbulence in the outer mixing layer. Cross-stream distribution of Reynolds stresses shows that the effect of inlet velocity profiles is more pronounced in the near field region of flow. Self-similarity is observed in the normalized turbulent shear stress profiles whereas considerable scatter can be noticed in the profiles of turbulent normal stresses for all the inlet velocity conditions. Two distinct peaks in the normalized turbulent kinetic energy profiles characterize the two shear layers of the jet and shifting of the outer peak toward the wall suggests a strong interaction of the outer layer with the inner layer as the jet develops.

Analyzing and modeling the interaction potential of the ground-state beryllium dimer

The factors that caused the Be${}_{2}$ potential to be quite different from other conventional van der Waals potentials are quantitatively delineated with relatively simple self-consistent-field calculations. By decomposing the potential into its three major components, we are able to show that the rather sudden change of slope in the potential energy curve around 3.2 \AA{} is the result of the interplay between the $sp$ hybridization and the correlation energy. It also enables us to model the interaction with a classical van der Waals potential, which provides the proper long-range behavior of the system, and a short-range attraction which mimics the effects of the $sp$ hybridization.

Thermoelectric transport across the metamagnetic transition of CeRu2Si2

We have measured the thermopower across the metamagnetic transition of the heavy fermion compound CeRu2Si2 at temperatures down to 0.1K and magnetic fields up to 11.5T. We find a large negative enhancement of the thermopower on crossing the metamagnetic field, as well as a sudden change in slope. We argue that this is consistent with the Zeeman-driven deformation of the Fermi surface through a topological transition. The field dependence of the thermopower highlights the discrepancy between thermodynamic and transport properties across the metamagnetic transition.

Thermodynamic properties of two-dimensional few-electrons quantum dot using the static fluctuation approximation (SFA)

The two-dimensional GaAs parabolic quantum dot (QD) is investigated in the static fluctuation approximation (SFA) where both the magnetic field and the electron–electron interaction are fully taken into account. The thermodynamic properties of the system are computed as functions of the temperature and magnetic field for different numbers of electrons ( N). It is noted that the mean internal energy increases with increasing number of electrons and magnetic field. This increase is not smooth, and a sudden change in slope is observed at a certain value of magnetic field for N≥4. It is found that the magnetization has sharp jumps for N≥4; for N≤3 a smooth monotonic diamagnetism is exhibited. A sharp peak is observed in the specific heat when the magnetic field is increased. It is found that the lowest-state transitions occur at a critical value of magnetic field. These transitions appear in the mean internal energy and magnetization.

Analysis of unpredictable intra-QRS potentials in signal-averaged electrocardiograms using an autoregressive moving average prediction model

Instead of extracting the abnormal intra-QRS potentials (AIQP) waveform, this study proposes the analysis of the unpredictable intra-QRS potentials (UIQP) based on an autoregressive moving average (ARMA) prediction model to detect the signals with sudden slope change within the QRS complex for the diagnosis of high-risk patients with ventricular tachycardia (VT). The UIQP is detected as the slope changes at slope discontinuities by the prediction error of the ARMA prediction model. Because of the linearity of the ARMA prediction model, the UIQP is also proportional to the amplitude of the QRS complex if the input QRS waves have the same shapes. Hence this study further defines the UIQP-to-QRS ratio to normalize the UIQP by the root-mean-square (RMS) value of the QRS complex. The study subjects were composed of 42 normal Taiwanese and 30 patients with sustained VT. The clinical results show that the UIQP-to-QRS ratios of the VT patients in leads X, Y and Z were significantly higher than those of the normal subjects. The logical combination of any 4 of the UIQP-to-QRS ratios and conventional time-domain parameters can increase the diagnosis performance of VT patients to 92.9% specificity, 93.3% sensitivity and 93.1% total prediction accuracy.

Ginzburg-Landau theory of noncentrosymmetric superconductors

The data of temperature dependent superfluid density $n_s(T)$ in Li$_2$Pd$_3$B and Li$_2$Pt$_3$B [Yuan {\it et al.}, \phrl97, 017006 (2006)] show that a sudden change of the slope of $n_s (T)$ occur at slightly lower than the critical temperature. Motivated by this observation, we microscopically derive the Ginzburg-Landau (GL) equations for noncentrosymmetric superconductors with Rashba type spin orbit interaction. Cooper pairing is assumed to occur between electrons only in the same spin split band and pair scattering is allowed to occur between two spin split bands. The GL theory of such a system predicts two transition temperatures, the higher of which is the conventional critical temperature $T_c$ while the lower one $T^*$ corresponds to the cross-over from a mixed singlet-triplet phase at lower temperatures to only spin-singlet or spin-triplet (depending on the sign of the interband scattering potential) phase at higher temperatures. As a consequence, $n_s (T)$ shows a kink at this cross-over temperature. We attribute the temperature at which sudden change of slope occurs in the observed $n_s (T)$ to the temperature $T^*$. This may also be associated with the observed kink in the penetration depth data of CePt$_3$Si. We have also estimated critical field near critical temperature.