摘要:

The data used in this work are size‐segregated aerosols collected from three ambient‐source sites with few interferences from nearby activities from fall into winter time in 1992. The analysis of the aerosol species is used to apportion source contributions to the aerosols sampled at Yen‐Ping elementary school situated in the Taipei metropolitan area. Concentration ratios of characteristic species to mass of near‐source aerosols are selected to represent source features. Source apportionment of water‐soluble ions with sea‐origin at Yen‐Ping site is calculated from the “chlorine loss” process. The inference on the compound forms of sulfates shows that (NH4)2SO4prevailing in the sub‐micron mode, whereas the sulfates from sea‐origin are undoubtedly dominant in the coarse mode. Estimate on source contributions for PM10aerosols at Yen‐Ping site shows that around 51% came from transportation activities, 23% from sea‐spray process, 17 to 19% from construction work, and 15% from the secondary chemical reaction. The procedure of this work overestimates source contributions by 6 to 8%.

ISSN:0253-3839    

DOI:10.1080/02533839.1996.9677760

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The methodology of the optimal control strategy of the non‐linear controlsystem, x = f(x)+ g(x)u, with the quadratic performance index based on the original non‐linear system variables,xandu, is developed and the optimal non‐linear control law which is the function of the non‐linear system properties,f(x) andg(x), and the weighting factorρ, is obtained. For the limiting case of the linear system,x = Ax + Bu,the non‐linear control can be reduced to the linear state feedback control which is exactly the same as that obtained by solving the well‐known Riccati equation. The simulations of an illustrative example of a level control system and the previous work of Ogunnaike are given to demonstrate this work.

ISSN:0253-3839    

DOI:10.1080/02533839.1996.9677761

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Three‐dimensional carbon fiber/epoxy resin composites are prepared, which have either three‐axis or five‐axis fabrics (3D‐3A or 3D‐5A) in four woven gauges and four specimen thicknesses. The impact properties of these 3‐D composites are studied. The results show that when the woven gauge is decreased by 1mm, the impact perforation energies of 3D‐3A and 3D‐5A are increased by 12.6J and 5.4J, respectively, and the impact perforation energy is increased by 38J when the specimen thickness is increased by 1mm. The initial impact energy of 3D‐3A is higher than that of 3D‐5A, but the propagation energy and ductility index of 3D‐5A with a woven gauge larger than 3.75mm are higher than those of 3D‐3A. In addition, the impact properties, the impact damage area and the strength loss after impact test are better when the woven gauge is decreased.

ISSN:0253-3839    

DOI:10.1080/02533839.1996.9677762

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

This paper presents a histogram‐based clustering method that automatically determines the number of clusters in a set of data points. Input data are first partitioned into several rectangular blocks. The number of points in each block is determined, and the thirty percent of the blocks with the most points are marked to obtain a feature. Next, the forty percent of the blocks with the most points are marked to obtain a second feature. These two features are then compared to determine the number of clusters in the input data. The proposed clustering method is fast, and the data to be clustered do not need to be linearly separable. Experimental results are included.

ISSN:0253-3839    

DOI:10.1080/02533839.1996.9677763

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The decomposition of 2‐chlorophenol by the ozonation process is studied and compared under various solution with different pH values and O3input mass flow rates to investigate the removal efficiency of reactants and organic intermediates. The disappearance rate of 2‐chlorophenol and the mineralization rate of organic intermediates by ozonation are found to increase in relation to increased O3input dosages and solution pH values. For alkaline solutions where HCO3‐and CO32‐species may accumulate as free radical scavengers, the mineralization of organic intermediates is found to be insignificant. The mineralization of organic intermediates is also found to be ineffective for acidic solutions because some organic acids form and are refractory for the ozone molecule. The 2‐chlorophenol in aqueous solutions are completely destroyed by ozonation within 30 minutes. The dechlorination of 2‐chlorophenol by ozonation was studied in solutions at various pH values. It is found that hydroxyl radicals may enhance dechlorination and destroy the 2‐chlorophenol in the solution. The detachment of chlorine atoms from the benzene ring is found to be the first step of the decomposition of 2‐chlorophenol in aqueous solutions. The two‐step consecutive kinetic model is found to fit the decomposition of 2‐chlorophenol by ozonation in aqueous solutions well.

ISSN:0253-3839    

DOI:10.1080/02533839.1996.9677764

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The phenomenon of water waves/soil interaction in a porous seabed has been extensively studied by geotechnical and coastal engineers in recent years. However, most previous investigations have simply considered the seabed as an isotropic medium, even though evidence of soil cross‐anisotropy has been reported in soil mechanic literature. In this paper, an analytical solution for wave‐induced soil response in a cross‐anisotropic seabed is proposed. Based on the new solution, together with the liquefaction criterion, the wave‐induced liquefaction potential can be estimated. As the numerical results presented shows, the influence of elastic anisotropic parameters on the wave‐induced pore pressure and the maximum liquefaction depth is significant.

ISSN:0253-3839    

DOI:10.1080/02533839.1996.9677765

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The removal of algal biomass and algal extracellular products (ECPs) from eutrophic water is studied using various physical chemical methods including coagulation/precipitation, powdered activated carbon (PAC) adsorption and combination of coagulation/ precipitation and activated carbon adsorption. The removal efficiencies of algae and TOC are 96% and 81%, respectively, by coagulation/ precipitation method. Moreover, dissolved organic carbon (DOC) is divided into four groups based on molecular weight distribution. It is found that coagulation/ precipitation process has good DOC removal efficiency for high molecular weight groups whereas PAC adsorption is particularly effective of the removal of DOC of low molecular weight. It is also discovered that the removal efficiency is synergistic by coagulation/ precipitation followed by PAC adsorption. The formations of THMFP/ DOC and AOXFP/DOC are higher with high molecular weight groups than those with low molecular weight groups.

ISSN:0253-3839    

DOI:10.1080/02533839.1996.9677766

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A protocol is a set of rules which govern the interaction between communicating machines. Protocol analysis and synthesis are two approaches to guarantee that the communication between two machines satisfies progress properties. Although the analysis approach is much easier to design and more flexible than the synthesis approach for general cases, the analysis approach usually suffers the state space problem. Moreover, the analysis approach can be used to detect logical errors in the protocol but not to correct those errors, while the synthesis approach can produce a correct protocol. To make a compromise between these two approaches and have advantage of both approaches, in this paper, we propose an algorithm to design correct protocols by applying both approaches. Given a protocol, we first apply the analysis approach to construct two machines which satisfy certain conditions. Then, we apply the synthesis approach to detect possible errors and provide the designer several choices to correct the errors.

ISSN:0253-3839    

DOI:10.1080/02533839.1996.9677767

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

In this paper, we investigate the problem of the robust pole assignment of a family of matrices by the Lyapunov method. We use the properties of induced norms and matrix measures to examine whether or not all the eigenvalues lie in the desired region. We also give a necessary and sufficient condition for the nominally determined quadratic Lyapunov equationejθE*P+e‐jθPE<2I.With this necessary and sufficient condition, the poles of the system lying in the desired region can be inspected more efficiently. Finally, examples are given to show the feasibility of the method.

ISSN:0253-3839    

DOI:10.1080/02533839.1996.9677768

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

This paper uses a 3‐D fiber laser Doppler velocimeter (FLDV) to measure the turbulent flow field inside a pancake type combustion chamber of a four‐stroke single cylinder transparent engine. Three components of the instantaneous flow velocity at the central point on a plane 10 mm below the cylinder head are obtained to characterize the flow field before combustion. The experiment employed a filtering method to resolve the high frequency turbulence and low frequency cyclic fluctuation from the instantaneous velocity data. In addition, a temporal autocorrelation coefficient, integral time and length scales, and a normalized power spectral density function are also calculated to characterize the turbulence structure. Variations of parameters, such as compression ratio and engine speed, are carried out in the experiment to study the effects of the design factor and the operation parameter on the characteristics of the in‐cylinder flow field.

ISSN:0253-3839    

DOI:10.1080/02533839.1996.9677769

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor