Turbid has been measured as a turbidity or as suspended solids. The information on particle size can not be obtained in above mentioned methods. The authors have tried to squeeze the characteristics of particle from the photometric measurement. The determination of particle diameter and distribution are included in this research.
In the analysis of photometric measurement, the authors have proposed the idea of dividing the light beam coming into the cell to a basic beam of light. The authors have considered the transformation of the incident light to both transmitting and dispersing lights at a turbid particle as a basic phenomenon. The idea of Markov chain contributes for describing the phenomena that occur in the basic beams of light.
It is confirmed that the decreasing rate of transmitting light followed by turbid concentration is proportional to minus one power of particle diameter. In case of assorting 2 kinds of particle diameter or more, the good correlation is also confirmed between dispersing light and moment based on particle number.

View full abstract

Because dozens of complaints are made every year alongside urban expressway, sequences of survey and constructions such as leveling the road, countermeasure at propagation course has experienced to solver this vibration problem. However, there are no real and general measures because the evaluation value VL (L10) on the boundary measured according to vibration measuring method defined by vibration control act is always less than limitation of requirement, therefore numbers of complaints are not decrease. In other words countermeasure to decrease vibration is difficult and there is high possibility for present evaluation method not to the sense of residents. This paper examine the evaluation method in high correlation with the dense of residents based on the study (vibration measuring and questionnaire) of the actual traffic vibration alongside elevated road.

View full abstract

Characteristics of pollution distribution and enlargement of pollution source are investigated using the real pollution records of twenty one pollution sites. Horizontal and vertical pollution enlargement are analyzed with various parameters such as soil profile and groundwater level, and the relationships between surface gas concentration and soil pollution are clarified. Modeling of pollution forms are conducted, and categorized to three forms; Loam plateau in Kanto area, Volcanic ash plateau in Kyushu and Hokkaido area and alluvial lowlands. A simple estimation method of pollution deposits, which needs only surface gas concentration distribution and a few boring investigation results, are proposed.

View full abstract

Year by year, it has become difficult to secure place to dispose sludge; thus, a new disposable method must be established. Considering these facts, in this study an incinerated sludge ash was tried as a raw material constituent of ceramic pipe. The practical application of this method was examined from the point of strength. And from this, it was found that 30% incinerated ash mixture rated ceramic pipe fully satisfied the standard for external pressure compression strength, and for bending strength and can be handle similarly as a regular ceramic pipe. Moreover, it was concluded that the usage of incinerated sludge ash was effective for saving natural resources and for lightening weight.

View full abstract

The effects of target compounds, co-existing substances, and their concentrations on the performances of ozone/vacuum ultraviolet process (O3/VUV) were investigated. The decomposition rates of malonate, acetate and oxalate ions were different one another depending upon the structure of the target compounds including their decomposition by-products and their concentrations. The study on the effects of co-existing substances (i. e., bicarbonate ion, nitrate ion and humic acid) revealed that humic acid is a stronger scavenger than bicarbonate or nitrate ions, and that nitrite formation during the simple VUV radiation (i. e., without ozonation) of a solution containing nitrate ion is depressed with ozonation with and without organic compounds.

View full abstract

Conventional dose-response models have been applied to calculate infection. However, conventional dose-response models are not suitable to evaluate an infection risk by pathogens in natural water environment since they do not include an existence probability of pathogens. This study presents a novel model that estimates a “risk” of infection by pathogenic microorganisms in water environment. This model was developed by combining the conventional dose-response model and the existence probability of pathogenic microorganisms in water environment. The modified beta-model was suitable to describe the risk by pathogenic bacteria and parasites, while the modified logistic model well described the infection risk by viruses.

View full abstract

It has been identified that the origin of the heterocyclic amines, a group of suspected human carcinogens is high-temperature heating of proteinaceous materials, e. g., food and plants (tabacco-leaves and woods). The heterocyclic amines have been found in human excretions and rain water. We extracted two of these heterocyclic amines, 3-amino-1-methyl-5H-pyrido[4, 3-b]indole (Trp-P-2) and 3-amino-1, 4-dimethyl-5H-pyrido[4, 3-b]indole (Trp-P-1) in the water of a sewage teatment plant in Japan by HPLC analysis. The concentration of Trp-P-2 and-1 were estimated at about 10^-2μg/L, each. The presence of these compounds shows the possible widespread pollution of surface waters with this class of carcinogens.

View full abstract

To analyze local residents' awareness about the new road across Tokyo Bay, we carried out a free response test about the road in four areas near the bay. The words written with higher frequency in the test are used for the analysis in each survey area. The difference of the frequency of each word among the survey areas is investigated by a hypothesis testing procedure. It is shown that characteristic concerns in each area are noise and air pollution caused by traffic flow, social affairs such as population growth and land price hike, and problems related to fisheries. The convenience of the road is a matter of primary interest in all the four areas.

View full abstract