ISSN:0253-3839    

DOI:10.1080/02533839.1992.9677441

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The purpose of this study is to take advantage of anaerobic biological fluidized bed reactors (ABFBR) in attempting to improve the limits of the anaerobic process in temperature, observing whether or not the advantages of ABFBR can be used to supplement the decrease in processing efficiency due to temperature drop. The experimental results are as follows: (1) Influent chemical oxygen demand (COD) concentration is from 250 ∼ 15000 mg/1, digestive temperature is above 21 °C, hydraulic retention time is 6 ∼ 8 hrs.; COD removal percentage averaged 70%. (2) The temperature correlation factor (θ) of the reaction kinetics constant (k) is close to 1.0. (3) Mixed liquor suspended solid (MLSS) is between 13.3–40.2 g/1 and increases as the temperature decreases, (4) At various digestive temperatures, the differences in the adenosine triphosphate (ATP) content of the unit volume bed are limited. (5) The digestive rates of domestic wastewater and monosodium glutamate fermented wastewater are very close to that of synthetic organic wastewater. When organic loading is within the range of 0.9–127.5 kg‐COD/m3• d, operating in proper operating conditions and within room temperature range, the digestive efficiency is very good, with very good adaptability to temperature changes.

ISSN:0253-3839    

DOI:10.1080/02533839.1992.9677442

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A simple method of similarity transformation is formulated to analyze a two‐dimensional creeping corner flow. By this peculiar transformation, governing equations for the plane velocity are reduced to a pair of ordinary differential equations. With a particular selection of appropriate boundary conditions, the field variables of velocity, pressure, vorticity, and stream function are obtained analytically. A special case with constant velocity at one boundary is explored. The salient characteristics of this example are used to compare with previous investigations. The present study shows that both approaches provide exactly the same solutions. A very interesting feature is that the velocity components in the coordinate system are independent of the radial direction.

ISSN:0253-3839    

DOI:10.1080/02533839.1992.9677443

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This study intends to generalize the concept of maximal volume in the tolerance region for characterizing the perturbations of one column or one row of the constraint matrix in a standard linear programming problem.

ISSN:0253-3839    

DOI:10.1080/02533839.1992.9677444

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Studies on the stability problem when a viscous incompressible fluid is filled into two concentric cylinders are usually conducted using the following boundary conditions: the outer cylinder remains stationary, and the inner cylinder rotates with constant angular speed. In this paper, we apply the notion of quasi‐steadiness to obtain analytic solutions to the same stability problem. The boundary conditions are such that the outer cylinder still remains fixed but the inner cylinder rotates with two different variable rotating surface speeds:V = V0(1 ‐e‐βt) andV = V0(1 ‐e‐βtcos δt). This is done using the principle of analogy and superposition. We also make a comparison between our calculated results and the work done by others. Thus, the authors hope that this paper can be useful to other researchers who work on similar problems.

ISSN:0253-3839    

DOI:10.1080/02533839.1992.9677445

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Arterial impedance is determined by physical properties of blood and vessel walls. Such factors include the blood viscosity and density, the wall viscoelasticity, and the vessel diameter. To account for wave transmission and reflection properties in arterial systems, an asymmetric T‐tube model, which consists of two uniform, viscoelastic tubes of different lengths representing the upper and lower extremities, is provided to simulate the arterial impedance spectrum. Each terminal complex load is a revised windkessel with compliance as well as resistance and inductance. Using representative data from the literature, parametric analysis shows that when peripheral compliances are increased, small moduli in the low frequency portions of the impedance spectra are produced, whereas alterations of either the characteristic impedances or inductances of the terminations have little effect on input impedance. The result of small moduli in the low frequency portions of the impedance spectrum associated with increasing peripheral compliances is quite different from that of the model of Liu et al. In animal studies and in theoretical considerations, there is evidence that the impedance spectrum predicted by our model can more closely mimic the impedance spectrum of the arterial system than that of Liu's model. Alteration of peripheral resistance only affects the impedance modulus at its dc term. Change in the elasticity or effective lengths of the tubes results in shifts in the positions of the maxima and minima similar to those observed experimentally. Alteration of the viscosity of the vessel walls or of the blood affects the fluctuations of the impedance spectra without affecting the positions of the maxima and minima. Thus, this simple model associated with transmission line theory provides more insight into the individual influence of various parameters of the proximal and peripheral vasculature on central hemodynamics.

ISSN:0253-3839    

DOI:10.1080/02533839.1992.9677446

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Since the discovery of the fast Fourier transform (FFT), many new FFT algorithms have been developed. Conventionally, the convolution‐based approach deals commonly with the prime length discrete Fourier transforms. In this paper, based on some theorems of Number Theory, a new algorithm for computing the FFT (with power of two length) is proposed. This novel recursive algorithm contains three stages, the first and the last stages contain only additions and substractions, and the second stage is of block diagonal form, with each block being a circular correlation/convolution matrix.

ISSN:0253-3839    

DOI:10.1080/02533839.1992.9677447

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In modern radar tracking systems, measurement noise is significantly correlated when the measurement frequency is high enough. The problem of maneuvering target tracking in the presence of complicated measurement noise is considered in this paper. The measurement noise is modeled as the sum of a high‐order autoregressive process and a white process. This noise can be decorrelated by including the noise‐correlation variables in the target state. The theoretical analysis of tracking performance is derived. If some of the parameters (including the noise‐correlation parameters) are unknown, these unknown parameters can be estimated adaptively using a modified innovation correlation method. This parameter estimation method is very useful when the measurement noise can be modeled as the sum of a first‐order Markov process and a white process.

ISSN:0253-3839    

DOI:10.1080/02533839.1992.9677448

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An experimental study of radar target discrimination using multiple‐frequency scattering amplitude without phase data is presented. Based on the concept of natural resonance frequencies, the technique is aspect‐angle independent so thata prioriinformation of the aspect‐angle is not necessary. The radar cross sections of a spheroid and a thin wire are measured at different aspect ‐ and bistatic‐angles to distinguish different spheroids and wires in the resonance frequency range. The results show that the discrimination algorithm works well and can be applied to both monostatic and bistatic radars.

ISSN:0253-3839    

DOI:10.1080/02533839.1992.9677449

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The ultimate strength of hot‐rolled wide flange steel columns has been studied extensively. However, very limited research work has been carried out on welded box columns, especially the jumbo type. This study focuses on the ultimate strength of welded jumbo box columns which are fabricated from four steel plates. The magnitude and distribution of residual stresses due to welding processes are measured from a series of test specimens. The effect of variations of residual stress, initial crookedness and material properties on the ultimate strength of welded jumbo box columns are carefully examined. Based on these experimental results and analytical studies, guidelines for calculating the ultimate strength of welded jumbo box columns are proposed.

ISSN:0253-3839    

DOI:10.1080/02533839.1992.9677450

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor