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1.
Since the natural estrogens 17 beta-estradiol (E2) and estron (E1), and the synthetic estrogen 17 alpha-ethynyl estradiol (EE2) have strong endocrine disrupting effects and the tendency to persist in effluent from wastewater treatment plants, effective measures are needed to remove them from wastewater. In this research, to gain an understanding of the characteristics of estrogen decomposition by ozonation, experiments were conducted using effluent from an actual wastewater treatment plant. In this experiment, estrogen was added to effluent at a concentration of 200 ng/l and 20 ng/l before the ozonation experiments. The results showed 90% or more of estrogen concentration and estrogenic activity of E2, El and EE2 to be removed at an ozone dose of 1 mg/l. At an ozone dose of 3 mg/l, the estrogen concentration and estrogenic activity of E2, El and EE2 in the treated water fell below the detection limit. The removal rate was not influenced by the kind of estrogen. No generation of byproducts with estrogenic activity was observed. The authors conclude that estrogen in secondary treated wastewater can be almost entirely removed at the practical ozone dose rate applied for the purpose of disinfection, which is up to about 5 mg/l.  相似文献   
2.
We examine the effect of simultaneous price changes on the total demand for a group of goods, which we call a compound commodity. Specifically, we consider unit and proportional cost components (e.g., taxes, transportation costs) imposed on compound commodities. If the unit cost is positive, then the proportional cost raises the relative price of the more expensive good, and thus induces substitution towards the less expensive good within this group. Then, the substitution effect of the proportional cost for a compound commodity is non‐negative if and only if the compound commodity and the other goods are, on average, not strongly substitutable.  相似文献   
3.
In recent years the school enrolment rates of children aged 13–15 and 16–18 years have increased sharply in Indonesia, not only in urban but also in rural areas. Using various data sets spanning the years from 1993 to 2007, this paper investigates changes in factors associated with the enrolment of secondary school aged children in rural areas. It sheds light on the roles of gender and of neighbourhood and school characteristics, which have rarely been examined in the Indonesian context. The study finds that the disappearance of a gender gap in secondary enrolments between 1993 and 2007 contributed significantly to the rise in the overall enrolment rate. The findings also show that children living in wealthier communities and communities with a high proportion of enrolled children are more likely to attend school. Finally, various school characteristics are shown not to be strongly or consistently correlated with school enrolment.  相似文献   
4.
After the Second World War, during the neutralization of the controlled economy of wartime Japan, a design for a Corporate Accounting Law was elaborated by the Investigation Committee on the Business Accounting System. The Investigation Committee tried to establish not only new business accounting standards but also a central and independent administrative organ of corporate accounting regulation on the basis of the Corporate Accounting Law. The Corporate Accounting Law was expected to lay the legal foundation of the new corporate accounting regulation regime in Japan. Nevertheless, even though the original design of the fundamental accounting law was never realized, it should be considered the starting point for our understanding of external accounting history in post-war Japan.  相似文献   
5.
We propose a new methodology for the valuation problem of financial contingent claims when the underlying asset prices follow a general class of continuous Itô processes. Our method can be applied to a wide range of valuation problems including complicated contingent claims associated with the term structure of interest rates. We illustrate our method by giving two examples: the valuation problems of swaptions and average (Asian) options for interest rates. Our method gives some explicit formulas for solutions, which are sufficiently numerically accurate for practical purposes in most cases. The continuous stochastic processes for spot interest rates and forward interest rates are not necessarily Markovian nor diffusion processes in the usual sense; nevertheless our approach can be rigorously justified by the Malliavin–Watanabe Calculus in stochastic analysis.  相似文献   
6.
This paper studies the approximation accuracy of a singular perturbation method for option pricing up to the second order under a stochastic volatility model. First, numerical experiments confirm that the first order approximation provides sufficiently accurate option prices in a fast mean-reversion volatility case. On the other hand, it creates relatively large errors in a non-fast mean-reversion volatility environment. Then, the second order approximation formula is derived and the improvement of the approximation is investigated.  相似文献   
7.
Consumers' positive dispositions relating to foreign countries, cultures, and products are an important yet under-researched topic, compared against the volume of research on consumers' negative dispositions towards the same. Cosmopolitanism, conceptualized as a general dispositional orientation reflecting an affinity for cultural diversity and the proclivity to master it, garners increasing attention as a variable for international market segmentation. Empirical studies on cosmopolitanism are scarce, principally due to the absence of scale demonstrating sufficient cross-cultural validity across languages. This research reports on such a validation, across four countries and five languages. Psychometric evaluations entailed a number of techniques, including multigroup confirmatory factor analysis. The results largely confirm the cross-lingual applicability of the cosmopolitanism scale.  相似文献   
8.
To enrich the literature on alliance termination, we recognize that the dynamics of individual alliances are subject to the structural characteristics of the alliance portfolios in which they are embedded. We anchor our study in the context of large industry leaders partnering with multiple small partners, the latter of which can be viewed as competing for access to the formers’ resources. We expect that a small partner’s relative capability in relation to peer partners within a leader’s alliance portfolio is negatively related to the likelihood of alliance termination, since the leader acknowledges that partners with inferior capability do not deserve to be supported. Furthermore, this relationship would be moderated by alliance portfolio size, market overlap with peer partners, and with industry leaders. Using a unique dataset of 145 alliances between leading and small department stores in Japan in the period 1977-93, we found general support for the hypothesized relationships.  相似文献   
9.
We propose a new methodology for the valuation problem of financial contingent claims when the underlying asset prices follow a general class of continuous Itô processes. Our method can be applicable to a wide range of valuation problems including contingent claims associated with stocks, foreign exchange rates, the term structure of interest rates, and even their combinations. We illustrate our method by discussing the Black-Scholes economy when the underlying asset prices follow the continuous diffusion processes, which are not necessarily time-homogeneous. The standard Black-Scholes model on stocks and the Cox-Ingersoll-Ross model on the spot interest rate are simple examples. Then we shall give a series of examples on the valuation formulae including plain vanilla options, average options, and other contingent claims. We shall also give some numerical evidence of the accuracy of the approximations we have obtained for practical purposes. Our approach can be rigorously justified by an infinite dimensional mathematics, the Malliavin-Watanabe-Yoshida theory recently developed in stochastic analysis.  相似文献   
10.
M. Yano and F. Dei have demonstrated that, by controlling the degree of competition in a non‐tradables market (competition policy), a country can influence the terms of trade so as to increase its welfare, relative to free trade. Using their model, this study compares the extent of this effect with that of a tariff policy. It demonstrates that a competition policy can achieve a higher utility than a tariff policy if tariff rates are at levels currently tolerated in the real world. This demonstrates that domestic competition policy may play an important role as a substitute for tariff policy.  相似文献   
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