Tsallis statistics and gradually truncated Levy flight - distribution of an economical index

Tsallis postulated a generalized form for entropy and give rise to a new statistics now known as Tsallis statistics. In the present work, we compare the Tsallis statistics with the gradually truncated Levy flight, and discuss the distribution of an economical index-the Standard and Poor's 500-using the values of standard deviation as calculated by our model. We find that both statistics give almost the same distribution. Thus we feel that gradual truncation of Levy distribution, after certain critical step size for describing complex systems, is a requirement of generalized thermodynamics or similar. The gradually truncated Levy flight is based on physical considerations and bring a better physical picture of the dynamics of the whole system. Tsallis statistics gives a theoretical support. Both statistics together can be utilized for the development of a more exact portfolio theory or to understand better the complexities in human and financial behaviors. A comparison of both statistics is made. (C) 2002 Published by Elsevier B.V. B.V.

Inelastic photoproduction at HERA: A second charmonium crisis?

Measurements of the inelastic photoproduction of charmonium at HERA have ignited a new charmonium crisis. The Color Singlet approach to computing onium production cross sections fits the data for large charmonium energy fraction z, where color octet models fail. This approach is however in qualitative disagreement with a wealth of information that exist on charmonium production by other initial states. We here suggest that the source of the discrepancy between color octet models (whether implemented in the soft color or NRQCD formalism) and data is due to the neglect of non-perturbative effects. Implementing these in a scheme originally developed for Drell-Yan phenomenology, we illustrate how agreement with the data is achieved. © 1999 Elsevier Science B.V. All rights reserved.

Regional hydroclimatic variability and Brazil's 2001 energy crisis

Purpose - This paper seeks to address the issue of persistent and widespread drought conditions during 2000 and 2001, which were the apparent cause of the decline of water levels in the reservoirs of Brazilian hydroelectric power plants. Design/methodology/approach - This issue is addressed here through a case study of the hydroclimatology of the Paraíba river basin, in Southeast Brazil, home to four large multi-purpose operational reservoirs. Findings - The data analysis shows that neither changes in the frequency nor magnitude of extreme hydrological events (droughts and floods) nor in annual rainfall amounts can be detected from the existing climate record. The explanation is consistent with the fact that the terrestrial water and energy cycles are tightly, and non-linearly, coupled through evapotranspiration. Research limitations/implications - Therefore small change in the seasonality of rainfall can have a significant impact on the basin's overall hydrologic regime, and thus on the availability of water resources. Originality/value - Often, adaptation and resilience to climate variability are discussed in the context of catastrophic events such as floods and droughts. This study suggests that a different type of impacts, those associated with subtle, yet persistent changes of seasonality in the terrestrial water cycle, cannot be ignored in studies of long-term sustainability of water resources. © Emerald Group Publishing Limited.

Economical analysis of ethanol steam reformer for hydrogen production associated with a sugarcane industry

An expressive amount of produced hydrogen is generated by customers in-situ such as petrochemical, fertilizer and sugarcane industries. However, the most utilized feedstock is natural gas, a non-renewable and fossil fuel. The introduction of biohydrogen production process associated in a sugarcane industry is an alternative to diminish emissions and contribute to create a CO2 cycle, where the plants capture this gas by photosynthesis process and produces sucrose for ethanol production. The cost of production of ethanol has dramatically decreased (from about US$ 700/m3 in 1970s to US$ 200/m3 today), becoming this a good option at near term, inclusively for its utilization by customers localized in main regions (localized especially in regions such as Southeastern Brazil) Also in near future, it will possible the utilization of fuel cells as form of distributed generation. Its utilization could occur specially in peak hours, diminishing the cost of investments in newer transmission systems. A technical and economic analysis of steam reformer of ethanol to hydrogen production associated with sugarcane industry was recently performed. This technique will also allow the use of ethanol when its price is relatively low. This study was based on a previous R&D study (sponsored by CEMIG - State of Minas Gerais Electricity Company) where thermodynamic and economic analyses were developed, based in the development of two ethanol steam reformers prototypes.x In this study an analysis was performed considering the use of bagasse as source of heat in the steam reforming process. Its use could to diminish the costs of hydrogen production, especially at large scale, obtaining cost-competitive production and permitting that sugarcane industry produces hydrogen in large scale beyond ethylic alcohol, anhydrous alcohol (or ethanol) and sugar.

Developed and studies on technical and economical viability of an environmental efficient urinal

This work introduces an innovative urinal for public convenience, that promotes at the same time water reuse and personal higiene, in a safe and economical way . Furthermore it demonstrates the latest technology and its technical and economical viabillity of utilization in new and already existing buildings facilities. This new model of personal higiene equipment offers as main benefits the improved economy with subsequent decrease in drinkable water consumption, sanitary safety, low cost and easy installation due to its simplicity and to the fact that it can be installed in already existing facilities. The proposal is constituted by a higienic, ecological and smart system for flushing of public urinals. It is a conjugated system of lavatory and urinal that reuses hands higienization water from the lavatory for flushing purpose. The proposed urinal can be operated manually or automatically by means of a presential sensor. The system promotes drinkable water economy by a rational utilization by avoiding the use of waste water from hand washing in place of clean water for flushing. The proposed equipment increases the economy of clean water in a simple and economical way and it can be installed in any type of public lavatory facilitie such as schools, public buildings, hospitals, commercial buildings, bus terminals, airports, stadiums, parking buildings and shopping centers. Additional benefits of the proposed system is the suggestion of hands washing before and after the use of the urinal without contamination risks from focet handling.and render more attractive the installation for a rational use of clean water in commercial and industrial buildings. Pay-back has shown to be very attractive for a number of internal return rates and also very attractive from the point of view of environmental protection.

Use of soybean oil fry waste for economical biosurfactant production by isolated Pseudomonas aeruginosa using response surface methodology

The present study sought biotensoactive production from soybean oil fry waste using Pseudomonas aeruginosa ATCC 10145 and Pseudomonas aeruginosa isolated from the soil of a petroleum station having undergone gasoline and diesel oil spills. The results of the experiments were analyzed using a complete factorial experimental design, investigating the concentration of soybean oil waste, ammonia sulfate and residual brewery yeast. Assays were performed in 250-mL Erlenmeyer beakers containing 50 mL of production medium, maintained on a rotary shaker at 200 rpm and a temperature of 30±1 °C for a 48-hour fermentation period. Biosurfactant production was monitored through the determination of rhamnose, surface tension and emulsification activity. The Pseudomonas aeruginosa ATCC 10145 strain and isolated Pseudomonas aeruginosa were able to reduce the surface tension of the initial mexlium from 61 mN/m to 32.5 mN/m and 30.0 mN/m as well as produce rhamnose at concentrations of 1.96 and 2.89 g/L with emulsification indices of 96% and 100%, respectively.