Rise Portion Research Articles

Application of Al2O3/iron-based composite abrasives on MAF process for inner surface finishing of oval-shaped tube: predicting results of MAF process using artificial neural network model

The oval-shaped tubes are the valuable product for using to transport the clean gas and high-purity solutions in the field of aerospace, semiconductor, LCD, and medical industries. However, due to their complex shape, it could significantly difficult to improve their inner surface quality by the conventional processes. In this study, the application of Al2O3/iron-based composite abrasives on magnetic abrasive finishing (MAF) process was used to finish the inner surface of oval-shaped SUS 316L tubes. Their inner surface was finished by a mixture of magnetic abrasive tools of Al2O3/iron-based composite abrasives with Fe powders, and light oil. An artificial neural network (ANN) model was used to predict the results of MAF process and then was compared with the actual test. It is found that the results predicted by the ANN model have significant agreement with the actual test results. The correlation coefficient (R2) for both training and testing of surface roughness on span and rise portion is larger than 0.92, and RMSE values for both cases are extremely small (less than 0.01). The actual test results showed that the inner surface of oval-shaped SUS 316L tube was smoothly improved from 0.24 μm to 0.05 μm and 0.04 μm on the rise and span portion, respectively. The application of Al2O3/iron-based composite abrasives on MAF process is an efficient method for inner surface finishing of the oval-shaped tubes.

An Inflection Point Method for the Determination of Pulmonary Transit Time From Contrast Echocardiography.

Indicator-dilution curves (IDCs) for the estimation of pulmonary transit times (PTTs) can be generated noninvasively using contrast echocardiography. Currently, these IDCs are analyzed by manual inspection, which is not feasible in a clinical setting, or fit to a statistical model to derive parameters of interest. However, IDCs generated from patients are frequently subject to significant low-frequency noise and recirculation artifacts that obscure the first-pass signal and render model fitting impractical or inaccurate. Thus, the objective of this paper was to develop alternative computational methods to determine PTT using noisy clinical data in which the signal decay is not adequately visible. We report on a method that uses a model fit to the rise portion of the IDCs to determine the signal inflection point. Additionally, a signal truncation algorithm was developed that enables automated analysis of the IDCs. We compare PTTs derived from our inflection point method to those obtained by manual inspection in 25 patients (R(2) = 0.86) and to those obtained by mean transit time calculation following fitting to a local density random walk model (R(2) = 0.80) in a subset of this cohort. Combined with a signal truncation algorithm, the inflection point method provides robust, automated determination of PTT from noisy IDCs containing recirculation artifacts. The inflection point method addresses the need for computational analysis of IDCs obtained from contrast echocardiograms that are not amenable to first-pass model fitting.

CONSTRAINING TYPE Ia SUPERNOVAE PROGENITORS FROM THREE YEARS OF SUPERNOVA LEGACY SURVEY DATA

While it is generally accepted that Type Ia supernovae are the result of the explosion of a carbon-oxygen White Dwarf accreting mass in a binary system, the details of their genesis still elude us, and the nature of the binary companion is uncertain. Kasen (2010) points out that the presence of a non-degenerate companion in the progenitor system could leave an observable trace: a flux excess in the early rise portion of the lightcurve caused by the ejecta impact with the companion itself. This excess would be observable only under favorable viewing angles, and its intensity depends on the nature of the companion. We searched for the signature of a non-degenerate companion in three years of Supernova Legacy Survey data by generating synthetic lightcurves accounting for the effects of shocking and comparing true and synthetic time series with Kolmogorov-Smirnov tests. Our most constraining result comes from noting that the shocking effect is more prominent in rest-frame B than V band: we rule out a contribution from white dwarf-red giant binary systems to Type Ia supernova explosions greater than 10% at 2 sigma, and than 20% at 3 sigma level.

Analysis of elastic stress wave propagation through a complex composite structure

A one-dimensional impact problem is employed for a layered system that comprises heterogeneous materials with different geometrical configurations. The system mimics transmitter for Multiple Integrated Laser Engagement Systems (MILES). The analytical model tracks the stress wave propagation through this layered structure as a result of the mechanical shock from blank rounds as they fired. The results clearly support the hypothesis that layered systems will suffer stress amplification with inherent acoustic impedance mismatch between layers. It is evident that the time dependent stress response in the rise portion is significantly affected by impedance mismatch and the number of layers.

Multicolor Infrared Observations of SN 2006aj. I. The Supernova Associated with XRF 060218

We report simultaneous multicolor near-infrared (NIR) observations of the supernova associated with x-ray Flash 060218 during the first 16 days after the high energy event. We find that the light curve rises and peaks relatively fast compared to other SN Ic, with the characteristic broad NIR peak seen in all three bands. We find that the rise profile before the peak is largely independent of NIR wavelength, each band appearing to transition into a plateau phase around day 10--13. Since the light curve is in the plateau phase when our observations end at day 16, we can only place limits on the peak absolute magnitudes, but we estimate that SN 2006aj is one of the lowest NIR luminosity XRF/GRB associated SNe observed to date. The broad peaks observed in the {\em JHK$_s$} bands point to a large increase in the NIR contribution of the total flux output from days 10--16. This evolution can be seen in the broad color and SED diagrams constructed using {\em UBVRIJHK$_s$} monochromatic flux measurements for the first 16 days of the event. Ultimately, a 10-day rise time would make SN 2006aj an extremely fast rise SN Ic event, faster than SN 1998bw and SN 2003dh, which combined with its underluminous nature, indicates a lower amount of $^{56}$Ni ejected by the progenitor compared to other XRF/GRB-SNe. Furthermore, the lack of significant color change during the rise portion of the burst points to little or no spectral evolution over the first 10 days of activity in the NIR.

Origination of gamma-ray burst pulses associated with the Doppler effect of spherical fireballs or uniform jet

Ryde and Petrosian have pointed out that the rise phases of gamma-ray burst (GRB) pulses originate from the widths of the intrinsic pulses and their decay phases are determined by the curvature effect of the expanding fireball surface based on their simplified formula. In this paper we investigate in detail the issue based on the formula in Ref. [20], which is derived based on a model of highly symmetric expanding fireballs, where the Doppler effect is the key factor to be concerned about, and no terms are omitted in their derivation. Our analyses show that the decay phases of the observed pulses originate from the contributions from both the curvature effect of the expanding fireball and the two timescales of the local pulses, and the rise phases of the observed pulses only come from the two timescales of the local pulses. Associated with a local pulse with both rise and decay portions, the light curve of GRBs in the rise portion is expected to undergo a concave phase and then a convex one, whereas that in the decay portion is expected to evolve by an opposite process. And the ratio of the concave timescale to the convex one in the rise phase of the observed pulse linearly increases with the ratio of the rising timescale to the decay one of the local pulse (rrd), whereas the ratio of the convex timescale to the concave timescale in its decay phase linearly decreases with rrd. The two correlations are independent of the local pulse forms and the rest-frame radiation forms. But the different forms of local pulses and the different values of rrd gives rise to the diversity of the light curve pulse shapes. We test a sample of 86 GRB pulses detected by the BATSE instrument on board the Compton Gamma Ray Observatory and find that the characteristics do exist in the light curve of GRBs.

Radio frequency emissions from a runaway electron avalanche model compared with intense, transient signals from thunderstorms

We present a one‐dimensional model of a runaway electron avalanche in a thunderstorm electric field. Previous simulations have calculated the ionization rates and energy distribution functions for runaway electrons, for various atmospheric values of E/p, through the solution of the modified relativistic Boltzmann equation. We use the field‐ and pressure‐dependent ionization rates in a hydrodynamic macroscopic treatment. The runaway electron avalanche modeled here includes the production of runaway and low‐energy electrons, electric field relaxation, electron attachment, and runaway electron loss. The model ambient electric field is established from two disks of charge with a sinusoidally spatially varying charge density of 9 nC/m3 peak amplitude. The peak ambient electric field from this configuration is 538 kV/m at 5 km. The numerically calculated radio frequency radiation exhibits relativistic effects. We hypothesize that runaway electron avalanches are sources of intense HF/VHF impulses radiated from within electrified clouds. The results from this case study are compared with ground‐based and FORTE satellite observations of HF and VHF radiation observed during the rise portion of narrow bipolar pulses (NBP). Given the specified rates and ambient environment, the radiation electric field HF and VHF spectra covering 3–25, 26–48, and 60–66 MHz are in agreement with observations for limited angular ranges. The modeled peak radiation electric field in the time domain is just below one standard deviation from the observed mean for NBPs.

Medial Displacement Calcaneal Osteotomy: Biomechanical Effect on Calcaneal Inversion

Purpose : This study was performed to investigate the dynamic effect of medial displacement calcaneal osteotomy (MCO) on the calcaneal inversion. Materials and Methods : 10 fresh-frozen, intact cadaver foot-ankle specimens were tested, using a custom loading apparatus at an orientation consistent with the early heel rise portion (40%) of the gait cycle. Calcaneal inversion was measured with identical ground reaction force and tendon force, before and after MCO. Results : Calcaneal inversion was in the pre-osteotomy condition and after MCO. Calcaneal plantar flexion was in the pre-osteotomy condition and after MCO. Increases of calcaneal inversion and flexion were significant (intact vs. MCO), (p

Effective propellant modulus approach for solid rocket motor ignition structural analysis

A study was performed to determine an effective propellant modulus that would accurately predict solid rocket motor propellant deformation during the rise portion of the ignition event. The propellant was characterized as a linear viscoelastic material. By assuming that the propellant experiences a constant strain rate event, an effective time-dependent modulus was calculated. A second effective time dependent modulus was calculated by assuming that the propellant experiences a constant stress rate event. To determine which effective modulus was representative of propellant behavior, a finite element analysis was performed using ABACUS. The propellant was characterized by means of a Prony series. The results of the analysis showed that the propellant displacements during the rise portion of the ignition event were accurately represented by a constant stress rate effective modulus. Constant strain rate effective modulus over-predicted the displacements computed by ABAQUS.

Photoconducting TiO 2 prepared by spray pyrolysis using TiCl 4

TiO 2 was prepared by the oxidation of TiCl 4 at relatively low deposition temperatures using spray pyrolysis. For a fixed carrier gas (N 2) flow rate, the substrate temperature is the critical parameter determining the film properties. Films made near 595 K contain only the anatase phase, adhere well to the glass substrate, and have a relative optical transmission of about 75% (between 450 and 850 nm), the value one calculates for the non-absorbing anatase phase in this region. These films have an absorption edge characteristic of a direct gap semiconductor with allowed transitions and optical gaps of 3.5–3.7 eV, depending on the porosity. At higher substrate temperatures (above 635 K), the resulting films have a cloudy appearance and they contain both the rutile and the anatase modifications, confirmed by X-ray diffraction. Lower temperature substrates reduce the deposition rate and yield more porous films. For the pure anatase films, the dark conductivities are about one order of magnitude larger, and the photoconductivity is about one order of magnitude smaller when measured with the sample in air, than those observed when the sample is in a vacuum. When the samples are in a vacuum, the conductivities of the clear films increase by about two orders of magnitude (from about 10 −10 to about 10 −8 S cm −1) when illuminated with light from an electrically programmable read-only memory eraser (mercury light), which gives an intensity of about 30 μW cm −2 at the sample. The photoresponse has two parts; the fast portion rises in less than 1 s to 99% of its final value, followed by a small slow rise portion. The slow response, which is more pronounced in the decay process, is interpreted as being due to the presence of surface trapping states.

Gravity trends as an expression of lithospheric extension on the southern margin of Australia

Gravity anomaly trends from the southern margin of Australia and its associated ‘margin basins’ support the hypothesis that margin formation has been related to two distinct phases of lithospheric extension. Seismic data indicate that extension with a northwest to southeast orientation led to formation of the Eyre Sub‐basin in the pre‐Late Jurassic (Oxfordian): the gravity trends indicate that extension probably took place throughout the region west of the Otway Basin. Extension with a north‐northeast to south‐southwest orientation created the Gippsland Basin in the Early Cretaceous and, as indicated by the gravity, appears to have extended across the entire Otway‐west Tasmania‐South Tasman Rise portion of the margin. Structural considerations and gravity lineaments suggest that the proto‐Otway Basin, the west Tasmania margin and the northeast margin of the South Tasman Rise were probably strike‐slip features in the pre‐Late Jurassic. The almost orthogonal geometries of the two phases of extension must ha...

Musical tone producing device of waveshape memory readout type

In a typical musical tone producing device of a full waveshape readout type, a full waveshape of a musical tone to be produced from the start to the end of sounding or a rise portion and a part of the waveshape following the rise portion of the musical tone is stored in a waveshape memory, and the musical tone is formed by reading out the waveshape from the waveform memory once, or reading out the rise portion once and thereafter reading out the partial waveshape repeatedly. A digital filter is introduced following the waveshape memory in this tone producing device. The filter characteristics are determined in accordance with a tone color change parameter such as the key touch or the tone pitch of the musical tone, thereby realizing a tone color change of the musical tone. Further, in order to realize timewise change of tone color of the musical tone, the circuit which has the tone color change parameter vary with time is proposed.

A METHOD FOR THE DETERMINATION OF THE THERMAL CONDUCTIVITY OF SANDSTONES USING A VARIABLE STATE APPROACH*

AbstractCommon problems encountered during the determination of the thermal conductivities of tight sandstones are rock specimen‐to‐heat source contact and complicated sample preparation. An experimental technique using an electromagnetic heat source solves the direct contact problem between the heat source and the sample. Also, it simplifies the sample preparation and reduces the measurement time.A CO2 laser operating in a pulsed mode is used as a heat source with about 500 W output power. Thus, heat losses due to radiation and air convection are negligible. Unpolished penny‐sized samples of tight sandstones are irradiated on one side and the temperature is measured on the opposite side. The temperature is recorded with 12‐bit accuracy by a digital data acquisition system. Carbon black is used to give the samples a uniform absorption.The transient temperature data are acquired, processed, and interpreted with interactive computer programs. Transients for each sample can be stacked, to improve the signal‐to‐noise ratio, and normalized. The thermal conductivity is calculated from the rise portion of the transient using a ridge‐regression type generalized linear inversion scheme.As many as 20 samples per hour can be measured with this simple but expensive set‐up. In the long run, this means a reduction of laboratory expenses. In addition, the resolution of this method is superior to other variable‐state measurement methods due to the real time controlled data acquisition and the numerical interpretation.

Model for diffusion‐limited electrochemiluminescence

AbstractAn approximate analytic expression is derived, based on a novel model for the reactive–diffusive processes in a electrochemiluminescence (ecl) experiment. The physical system treated is one in which ecl is produced by stepping the voltage of a planar electrode to the diffusion‐limited reduction value for an emitter species in the presence of a bulk oxidant precursor (9,10‐DPA with benzoyl peroxide). The unknown rate constants are determined by a least‐squares curve‐fitting computer code. The model, though crude, provides an excellent fit to the ecl intensity versus time data, including the rise portion of the curve.

On the Periodic Response of Cam Mechanism With Flexible Follower and Camshaft

Researchers in recent years have shown a great deal of interest in the study of the dynamic response of cam-follower systems, with one or more of its components treated as being elastic. Within the assumption of a lineaar analysis, and limited to stable regions, a single degree-of-freedom linear second order differential equation of motion is developed for a cam mechanism consisting of elastic follower and camshaft. This development is consistent, as are some simplifying assumptions, with the works of current authors. The governing equation is shown to possess time-dependent periodic coefficients, for a constant imput angular velocity. Conventionally, the rise portion of the cam motion cycle has been treated as the source of excitation, and the transient follower-motion computed during the excitation (rise) as well as the subsequent dwell periods. The one basic assumption in these works, however, has been that the residual vibration is damped out during the dwell period and does not carry over to the next motion cycle. In this paper, the authors forego this assumption and present a method for not only incorporating the excitation effects due to the return stroke, but also for obtaining the steady-state response of the follower. Some illustrative examples are presented, and even though no comprehensive set of cam-profile types are examined, some basic conclusions are reached using a representative cycloidal cam profile.

ELECTROCHEMICAL GENERATION OF SOLUTION LUMINESCENCE—III.: EFFECT OF OXYGEN ON QUANTUM YIELD AND KINETICS OF LUMINOL

Abstract ‐The growth and decay of light emission were examined for luminol as a funtion of oxygen concentration in aqueous alkaline solutions during and after the application of a controlled potential, square‐wave electrochemical pulse. The results indicate that, in the rise portion of the light, the rate of electrochemical oxidation of luminol governs the light emission rate; while in the decay portion, the rate is first order and is independent of oxygen concentration. Quantum yields based on integration of the total light emitted also appear to be independent of oxygen above a threshold value. These results are consistent with evidence that the emitting state is an excited singlet.