Image processing of seismograms: (a) Hough transformation for the detection of seismic patterns; (b) thinning processing in the seismogram

Hough transformation is used to detect the seismic patterns on the seismogram. The system of Hough technique includes envelope generation, thresholding, Hough transformation, and parameter determination. Visual inspection method, local peak detection method, and clustering algorithm are used to determine the parameters. Thinning algorithms are used for the skeletonization of the seismic reflectors in the seismogram. The thinning algorithms used are fast parallel thinning algorithm and 2D thinning algorithm preserving 8- and 4-point neighbor connectivities.     

A process planning strategy for removing an arbitrary profile by hydrodynamic polishing process

A process planning strategy for removing an arbitrary profile by a deterministic polishing process is proposed. This strategy suggested that to remove an arbitrary profile the time-distribution of the tool motion at themachining area can be designed to be a linear function of the profile. Because the area of the instantaneous machining zone is finite and the machining rate distribution at this zone is not uniform, this strategy may cause a difference between the desired and machined profiles. The possible errors are classified into two groups: the machining time-distribution error and the ripple error. It is shown that the machining time-distribution error is significant only at the boundary of the machining area. By increasing the size between two conjoint tool positions, this error can be reduced. The size of the instantaneous machining zone has little effect on this error if the size ratio between this zone and two conjoint tool positions is fixed. On the other hand, the ripple error will occur over the whole machining area. The smaller the distance between two conjoint tool positions, the smaller the ripple error will be. The experimental study indicated that the analytical prediction is correct and an arbitrary profile can be accurately removed according to this proposed strategy.     

Statistical and spatial properties of forest clutter measured withpolarimetric synthetic aperture radar (SAR)

The purpose of this study was to assess the characteristics of the polarimetric radar clutter collected over various types of vegetation, and to evaluate the potential utility of various measures for classifying vegetated terrain. It utilized airborne radar data collected in October 1988 of pure and mixed stands of jack pine and aspen located in central Minnesota, and data collected in August 1989 of forested areas surrounding Durham, NC. The measured parameters are the polarimetric signature, a statistical distribution shape parameter, and the texture autocorrelation function. A method is presented for calculating the texture autocorrelation from single-look complex SAR imagery. Comparison of parameters from different clutter types at a variety of frequency, polarization, and incidence angle combinations showed that different terrain types exhibit unique polarimetric, statistical, and spatial properties     

Magnetic and transport properties of PrBa2Cu4O8-δ prepared at 1 atm oxygen pressure

Measurements of physical properties were performed on the PrBa₂Cu₄O_8- sample prepared by the sol-gel method and sintered in I atm oxygen pressure. Instead of exhibiting superconductivity as for R Y or Gd in the RBa₂Cu₄O_8- compound. This compound is unstable, insulating but metallic-like at low temperatures. No superconductivity was observed down to 2 K. Since PrBa₂Cu₄O_8- can be re-written as Cu₂Ba₂PrCu₂O_8- which is a compound of two CuO₂-layers and two CuO-chains, the possibility of anomalous Pr antiferromagnetic ordering around 18 K observed from preliminary magnetic data and the effect of oxygen stoichiotmetry parameter on the metal-insulator transition are explored.     

Chemical reaction and mixing inside a coalesced droplet after a head-on collision

We investigated the phenomena of a chemical reaction inside a coalesced droplet after a direct (head-on) collision. A droplet containing an alkaline solution collided with a droplet containing a pH indicator on a surface with a wettability gradient. We used a high-speed camera to observe the color-changing reaction inside the coalesced droplet. Compared with a traditional dye-mixing test, the chemical reaction inside the coalesced droplet facilitated the mixing of two counter-reactive fluids and was more than 100 times as efficient as for unreactive fluids mixing inside the coalesced droplet. Instead of mere mixing, a chemical reaction inside a coalesced droplet is valuable for applications in a digital microfluidic open system. In droplet coalescence, the characteristics of the fluids and the ratio of volumes of two droplets caused a varied profile of the droplet coalescence, especially the neck curvature that affects the shape of the material interface between the two droplets at an initial phase. We observed the evolution of the chemical reaction with a varying radius of neck curvature inside the coalesced droplet. For the case of a small radius of neck curvature, the small interfacial area between two reactive fluids accumulated an intense heat of reaction and induced a rapid growth of the fingers. For the case of a large radius of neck curvature, the growth of fingers was slight and the interface was uniform across the large interfacial area. Our work illustrates a correlation between the rate of chemical reaction and the profile of a coalesced droplet, which is a significant reference in droplet-based microfluidic systems for biochemical applications.     

The method of uncertainty quantification and minimization using polynomial chaos expansions

Reliable simulations of reacting flow systems require a well-characterized, detailed chemical model as a foundation. Accuracy of such a model can be assured, in principle, by systematic studies of individual rate coefficients. However, the inherent uncertainties in the rate data leave a model still characterized by a kinetic rate parameter space which will be persistently finite in its size. Without a careful analysis of how this uncertainty space propagates into the model predictions, those predictions can at best be trusted only semi-quantitatively. In this work, we propose the Method of Uncertainty Minimization using Polynomial Chaos Expansions (MUM-PCE) to quantify and constrain these uncertainties. An as-compiled, detailed H₂/CO/C₁–C₄ kinetic model and a set of ethylene combustion data are used as an example. In this method, the uncertainty in the rate parameters of the as-compiled model is quantified. Then, the model is subjected to a rigorous mathematical analysis by constraining the rate coefficients against the combustion data, as well as a consistency-screening process. Lastly, the uncertainty of the constrained model is calculated using an inverse spectral technique, and then propagated into a range of simulation conditions to demonstrate the utilities and limitations of the method.     

Antidepressant-like effect of lemon essential oil is through a modulation in the levels of norepinephrine,dopamine, and serotonin in mice: Use of the tail suspension test

Lemon is widely consumed in the diet, but limited reports are available on lemon essential oil (LEO) as a functional food ingredient. Though some studies have focused on the effects of LEO inhalation on depression, very few studies have investigated the oral administration of LEO. In this study, the antidepressant effects of orally administered LEO were evaluated in mice by tail suspension test (TST) and their influence on the brain monoamines was determined. Our findings revealed that none of the LEO concentrations tested (200–1600 mg/kg) affected the spontaneous locomotor activity or elicited physiological/histopathological changes in mice. Compared with fluoxetine (18 mg/kg, p.o.) as a positive control, 400 mg/kg LEO effectively reduced immobility time in the TST-subjected mice. HPLC analysis indicated that LEO-gavaged mice had significant differences in the concentrations of norepinephrine, dopamine, and serotonin in the prefrontal cortex, striatum, and hippocampus, which might, at least in part, account for the antidepressant effect of LEO.     

A process planning strategy for removing arbitrary and axially symmetric profile by a polishing process

In this study, a machining strategy for a polishing process to remove an arbitrary and axially symmetric profile is proposed. The strategy is to plan the tool motion so that a desired profile can be accurately machined. From the volume removing analysis of a polishing process, it is suggested that the dwelling time of the tool at a position should be a linear function of the product of the depth to be removed by its corresponding radius. By using this strategy, three types of errors may be induced: the machining time–distribution error, the ripple error and the resolution error. It is shown that these errors are related to the profile, the tool step, the volume removing rate and the size of the machining zone. The qualitative and quantitative properties of these errors are analyzed. This analysis indicates that a dominant factor in deciding these errors is the tool step size. By increasing this size, both the machining time–distribution error and the resolution error are reduced but the ripple error is enhanced. A tactic is proposed to solve the conflict in choosing the tool step. The experimental study conforms that the proposed strategy can accurately remove an arbitrary profile and the error analysis is reasonable.     

Effects of cell correlations in a matched-filter PN codeacquisition for direct-sequence spread-spectrum systems

Rapid pseudonoise (PN) code acquisition with matched-filter correlators has been very popular in direct-sequence (DS) spread-spectrum systems. Conventionally, the analysis of this acquisition method is based on the assumption that the detections among cells are independent. However, there may be strong correlations among cell detections for the case that the cell size is less than a chip duration. In this paper, the mean acquisition time performance of the acquisition method is analyzed with the cell correlations being taken into account. Numerical results show that depending on the threshold value and other system parameters, the effect of cell correlations may be over 20% of the mean acquisition time for signal-to-noise ratios (SNR) of practical interest. The analytical results are substantiated by computer simulations     

Storage temperature and packaging condition affect the total phenolic content and antioxidant activity of black soybeans and koji

In this study, powders of steamed black soybeans and the Aspergillus awamori‐fermented black soybeans (koji) were subjected to storage at 4 °C and 25 °C with or without deoxidant and desiccant for 120 days. It was found that total phenolic content and the antioxidant activity including the DPPH radicals scavenging effect, Fe²⁺‐chelating ability and reducing activity of the methanol extracts from black soybeans and koji decreased as the storage period was extended. Furthermore, storage temperature and packaging condition affected the antioxidant activity of the methanol extracts of black soybeans and koji. After 120‐day storage, extract from black soybeans holding at 4 °C with deoxidant and desiccant exhibited the highest residual of DPPH radicals scavenging effect, Fe²⁺‐chelating ability and reducing activity of 71.78%, 72.66% and 70.04%, respectively. Meanwhile, the highest residual of 77.78%, 81.71% and 85.05% respectively, was noted with extract from koji held at 25 °C with deoxidant and desiccant.