Fractional power approximations of elliptic integrals and bessel functions

In the previous papers [1][3], fractional powers were used to approximate elementary functions and their usefulness was proved with experimental results. In the present paper, some further investigations are reported. That is, elliptic integrals in Legendre's canonical form and Bessel functions are approximated by fractional powers. As the fractional power approximation,

f(x) c₀ + c₁x + c₂x^p

is discussed. When all coefficients c₀, c₁, c₂, p are properly assigned, the accuracy of this approximation becomes comparable to that of the Chebyshev approximation using polynomials up to the third degree.     

Road traffic accidents and the Abbreviated Injury Scale (ais) in Japan

Although in Japan the number of casualties from road traffic accidents decreased substantially during a period of improvement of safety measures, in recent years it has remained rather constant. To decrease accidents still further it is necessary to investigate the circumstances of road traffic accidents and the severity of resulting casualties in detail. For this purpose 167,721 cases of road traffic accident casualties occurring between February and April 1979, throughout Japan were analyzed. (1) It was found that 74.2% of all the cases suffered injuries corresponding to AIS-1; 30% of these involved neck injuries. (2) There were 2,654 fatal cases, 67% of which involved head injuries, chiefly cerebral contusion, cranial base fracture, and intracranial hemorrhage. There were fatal cases in the categories of AIS-3 or below which are generally considered not fatal, but those were due to complications. (3) The chief sites of injury varied according to the victim's mode of transport: in an automobile the neck was the site most frequently injured; on a motorcycle the legs and head were usually involved; on a bicycle or walking the head and legs were most at risk. (4) Injuries to pedestrians often fell under the severer AIS-4 or higher codes and constituted 43% of total deaths. (5) Accidents with automobiles changing lanes tended to cause serious injuries and many deaths. Other characteristics of road traffic accidents in Japan are analyzed and discussed.     

An analysis of Pascal programs in compiler writing

A method and results of static and dynamic analysis of Pascal programs are described. In order to investigate characteristics of large systems programs developed by the stepwise refinement programming approach and written in Pascal, several Pascal compilers written in Pascal were analysed from both static and dynamic points of view. As a main conclusion, procedures play an important role in the stepwise refinement approach and implementors of a compiler and designers of high level language machines for Pascal-like languages should pay careful attention to this point. The set data structure is one of the characteristics of the Pascal language and statistics of set operations are also described.     

Harmonic analysis of a single-phase rectifier with a DC filter capacitor

A single-phase diode bridge rectifier with a filter capacitor on the dc side is often employed to convert ac input into a dc voltage. The input current of the rectifier contains harmonic currents which cause undesirable power line effects. Recently, a method using the time domain analysis has been proposed to calculate the harmonic currents of rectifier considering noninfinite capacitance, i.e., non-zero dc side impedance. This method is very accurate, but it requires a long computing time and a complicated algorithm. This paper proposes a new method that makes it possible to easily calculate the harmonic currents taking into account the effects of the ac and dc side impedances of rectifier. The proposed method, which is based on the frequency domain method, can be executed only with the algebraic computation, and its accuracy is quite high. The validity of the proposed method is also demonstrated by comparison with the results of time simulation.     

Scintillation from Eu2+ in Nanocrystallized Glass

A Eu²⁺-doped SiO₂–Al₂O₃–CaO–CaF₂ glass was prepared and converted into a transparent glass ceramic by heat treatment. The crystalline phase and its size were determined by X-ray diffraction and a transmission electron microscopy. The scintillation of Eu²⁺ ions in both glass and ceramic under X-ray excitation was investigated and compared with that in a single-crystal scintillator.     

Application of real-time PCR assays to genotyping of F-specific phages in river water and sediments in Japan

Genotyping of F-specific RNA phages is currently one of the most promising approaches to differentiate between human and animal fecal contamination in aquatic environments. In this study, a total of 18 river water and sediment samples were collected from the Tonegawa River basin, Japan, in order to describe the genogroup distribution of F-specific RNA and DNA phages using genogroup-specific real-time PCR assays. F-specific phages were detected in nine (100%) river water and six (67%) sediment samples. Eighty-five phage plaques were isolated from these samples and subjected to real-time PCR assays specific for the phages. F-specific RNA phages of human genogroups (II and III) were detected in 32 (38%) plaques, whereas those of animal genogroups (I and IV) were detected in 17 (20%) plaques. No correlation was observed between the genogroup distribution of F-specific RNA phages and the occurrence of human adenovirus genomes, suggesting that genotyping of the phages alone is inadequate for the evaluation of the occurrence of viruses in aquatic environments. SYBR Green-based real-time PCR assay revealed the presence of F-specific DNA phages in four (5%) plaques, which were further classified into two genogroups (fd- and f1-like phages) by sequence analysis. Thirty-two (38%) plaques were not classified as the F-specific phage genogroups, indicating the limited applicability of these real-time PCR assays to a wide range of aquatic environmental samples worldwide.     

SCR of NOx with NH3 over Cu/NaZSM-5 and Cu/HZSM-5 in the presence of decane

The selective catalytic reduction of NO_x with NH₃ in the presence of decane over Cu/ZSM-5 catalysts prepared from H⁺ and Na⁺ZSM-5 precursors were investigated. Cu/NaZSM-5 catalyst showed significantly higher NO_x conversion compared to Cu/HZSM-5. However, the presence of decane decreased the activity of both the catalysts, due to coke formation. Cu/HZSM-5 catalyst showed a larger decline in NO_x conversion with time on stream compared to Cu/NaZSM-5. The higher activity of Cu/NaZSM-5 is attributed, to the promoting effect of Na⁺ cations in the formation of active Cu⁺ and nitrite and nitrate intermediates species and retardation of coke formation.     

Dechlorination of chlorobenzene compounds on flyash; effects of metals, aqueous/organic solvents and temperatures

Dechlorination of chlorobenzene compounds on flyash by using a solution of calcium hydroxide and sulfur in aqueous/organic solvent at 60–170 °C, under oxygen deficient conditions was studied. High percentage of dechlorination was obtained under certain reaction conditions. The results suggested that at 90 °C, metals in general and copper and lead in particular enhanced the catalytic potential of flyash for dechlorination by hydrodechlorination and substitution reactions. But at high temperatures (120–170 °C), dechlorination process was adversely affected by these metals. The effects of water, organic solvents, temperatures and heating time, were studied and reactions conditions were optimized to get maximum dechlorination.