氧气平炉电除尘灰综合利用的新途径

氧气平炉的电除尘灰粒径小,水渗透性差,因而极易在空中飘浮,在装卸、运输、储存的过程中,易造成二次环境污染。用颗粒状没有粘性的平炉水淬渣作吸附体,与电除尘灰一起加水搅拌成渣灰混合料,既解决了电除尘灰对环境的污染问题,又为烧结厂提供了合格原料。     

New techniques for measuring maximum reflectance of vitrinite and dispersed vitrinite in sediments

Maximum reflectance, R_max, can be calculated by the following equation: $\text{R}{}_{\max }\text{= (}\text{R}{}_1\text{+ R}{}_3\text{2}\text{) + (}\text{(R}{}_1\text{? R}{}_2\text{)}{}^2\text{+ (R}{}_2\text{? R}{}_3\text{)}{}^2\text{2}\text{)}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ in which R₁, R₂, and R₃ are three separate reflectance readings on the same vitrinite grain at 45° angular intervals. The equation is derived from the reflectance distribution function for a central section of a reflectance indicatrix: R_α = R_maxcos²α + R′_minsin²α where R_α is the reflectance measured in the direction α degrees from R_max, R′_min is an apparent minimum which has the minimum value on this central section, and R_max ? R′_min ? R_min. This new technique can be further simplified by rotating the polarizer in 45-degree intervals to obtain three photometer readings and then converting them to R₁, R₂, and R₃, by the use of empirically-established conversion factors. The new techniques do not require the full revolution of the microscope stage and, therefore, are particularly suitable for measuring small grains of vitrinite.     

Magnetic properties of Ni-Fe films coupled with stripe-domain films

A study was made of the change in anisotropy field, coercivity, angular dispersion, and creep threshold of an ordinary Ni-Fe film when coupled with a stripe-domain film. It was found that the values of these properties all increased as a result of the coupling.     

Estimation for rotational processes with one degree of freedom--Part II: Discrete-time processes

General error criteria and probability distributions on the circle are studied in connection with estimation by using their Fourier series representations. Conditional probability densities for certain discrete-time folded normal processes, which are analogous to the continuous-time processes associated with the bilinear problems considered in Part I of this series, are computed. An intrinsic physical difference between the discrete-time and continuous-time problems is discussed, and the complexity of the estimation equations in the discrete-time case is analyzed in this setting. Suboptimal sequential filtering schemes are briefly discussed. In addition, Fourier analysis of conditional probability distributions exposes the inherent rich structure in quite general classes of estimation problems on the circle.     

Attenuation of 8.6 and 3.2 mm radio waves by clouds

Measured attenuations associated with a variety of cloud conditions at wavelengths near 8.6 and 3.2 mm are reported. Two specific events, during which heavy rain clouds covered the sky, are examined and statistical data collected over a six-month period on a variety of cloud types are presented. The number of observations of some cloud types was not large and it was not possible to account for the gaseous attenuation with sufficient accuracy to get reliable values for the attenuation by the cloud droplets for a number of cloud types. The clouds causing the largest attenuations were the rain-bearing cumulonimbus ones. Of the nonrain clouds the two types for which the sample sizes are adequate and attenuations are sufficient for meaningful conclusions are stratocumulus and cumulus, their 35 GHz/95 GHz mean attenuation values being 0.18/0.61 dB and 0.12/0.34 dB, respectively.     

Evaluation of protein concentrates prepared from rapeseed meal

Protein concentrates have been prepared from rapeseed meals by extraction with sodium chloride solution, followed by removal of the seed coat by screen filtration. This method yielded up to 75% of the original meal N in the form of products containing 61–64% protein (Nx 6·25). The products showed a considerably greater content of ash, and lower content of crude fibre and glucosinolate than did the starting meals, but amino acid patterns were similar and P levels were unchanged. Protein quality of the products prepared from heat-treated (myrosinase-inactivated) meals, was measured by determination of protein efficiency ratio and net protein utilisation, and was found to be similar to that of casein.     

Model-based fault diagnosis in continuous dynamic systems

Traditional fault detection and isolation methods are based on quantitative models which are sometimes difficult and costly to obtain. In this paper, qualitative bond graph (QBG) reasoning is adopted as the modeling scheme to generate a set of qualitative equations. The QBG method provides a unified approach for modeling engineering systems, in particular, mechatronic systems. An input-output qualitative equation derived from QBG formalism performs continuous system monitoring. Fault diagnosis is activated when a discrepancy is observed between measured abnormal behavior and predicted system behavior. Genetic algorithms (GA's) are then used to search for possible faulty components among a system of qualitative equations. In order to demonstrate the performance of the proposed algorithm, we have tested it on a laboratory scale servo-tank liquid process rig. Results of the proposed model-based fault detection and diagnosis algorithm for the process rig are presented and discussed.     

Formation of haloacetic acids during monochloramination

Factors that affect the formation of haloacetic acids (HAAs) during monochloramination, such as monochloramine application techniques, the initial chlorine (Cl) to ammonia-N (N) ratios, the bromide concentrations, and the wastewater quality, were studied. Aqueous humic acid solutions and undisinfected wastewater effluent samples obtained from two Hong Kong Sewage Treatment Works (STWs) were monochloraminated under various conditions. HAA formation was strongly affected by the monochloramine application techniques. The formation of trichloroacetic acid (TCAA) and total HAAs was reduced by adding preformed monochloramine. A higher initial Cl:N ratio indicated a higher chlorine demand and consequently led to higher HAA yields. Increasing the bromide concentration shifted HAAs from chlorinated species to brominated species and increased the yields of total HAAs, concurrent with decreases in the yields of dichloroacetic acid (DCAA) and TCAA but with increases in those of the other HAAs measured. Variations in the patterns of HAA formation were observed in monochloraminated wastewater effluent samples. The variations cannot be simply explained by the chlorine chemistry involving ammonia and/or bromide but are likely attributable to the combining effects of the water quality and the characteristics of the organics in the wastewater.     

A qualitative assessment methodology for road safety policy strategies

This paper proposes a qualitative assessment methodology that is comprised of a cluster analysis and an autoregression analysis that assess the effects of various road safety strategies implemented in Hong Kong over the last 10 years. The cluster analysis is first used to group over a hundred road safety projects and programs into a smaller set of meaningful road safety policy strategy clusters. These strategies, together with the trend factor, seasonal pattern, car crashworthiness and meteorological data are then used in the autoregression analysis to relate to the fatality and casualty rates of drivers, passengers, motorcyclists, and pedestrians. This method allows the evaluation of the overall effects of the road safety strategies, and the effects and relative significance of each individual strategy. The evaluation method is described, and the main findings of the study are discussed.