bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrated Fault Seal Characterization for Reservoir Management
Authors: Acharya U.K. , Eisenberg R.A. , Brenneman R.J. , Adeogba A.A.
Published: April 2008

Integration of pressure, production, geochemical, seismic, well log and structural data provides important information on the sealing capacity and dynamic behavior of fault-juxtaposed reservoirs. Reservoir juxtapositions and potential cross-fault communication pathways are easily defined with fault plane sections (Allan maps). Smear gouge ratios, calculated from E-logs, are used to estimate the composition of fault-gouge materials between the juxtaposed reservoirs. History matching of the available production and pressure data with a full-field reservoir simulator are used to quantify the relationship between fault gouge composition and fault transmissibility. This paper presents the results of such a study conducted on the Meren field, Nigeria. The computed fault transmissibility was observed to correlate with the Smear gouge ratio (fault gouge composition). These tools are used to augment the interpretation of seal/nonseal character in proved reservoirs, assist in the quantification of fault-seal risk in untested fault-dependent closures and prove valuable in the management of reservoirs.

Introduction

Identifying the best practices for the development and management of a hydrocarbon reservoir involves integration of both the geology and reservoir engineering features of the field. The geological data could include information on depositional environment, which can be used to gauge the areal extent of the field; structural geology, to identify the structural features including faults, their areal extent, amount of slip, and sand/sand juxta position; and geochemical data that can be used to fingerprint the oil indifferent reservoirs and to identify possible communication, if any, existing between them either along or across a fault. Reservoir engineering and historical production data could be used to enhance the geologic interpretation and to assist in quantifying the effects of these geological features on the long-range production behavior of the reservoirs.

In the present work the main purpose of the study was to analyze the behavior of faults from the standpoint of their conductance. Both geological interpretation and reservoir engineering analyses were used in this study of the Meren field, offshore Nigeria. The analysis involved a geological study of the faults using Allan maps to estimate the extent of the sand/sand juxta position, Smear Gouge Analysis (SGA) to quantify the nature of the fault gouge, and Reservoir Simulation to estimate the transmissibilities of the fault gouge.
Impact of jerry can disinfection in a camp environment – experiences in an IDP camp in Northern Uganda
Authors: Steele Andre , Clarke Brian , Watkins Owen
Published: April 2008

In July 2007, a study by the Centre for Environmental Health Engineering, at the University of Surrey, assessed a modified method of jerry can cleaning in an internally displaced persons (IDP) camp in Kitgum, N. Uganda. The poor condition of drinking water vessels used in the camp was confirmed as a potential source for microbiological contamination both visually and by microbiological testing. Jerry cans were disinfected using high strength sodium hypochlorite (NaOCl) generated using an experimental AquaChlor Solar unit. The study suggested that regular jerry can cleaning, using a high strength chlorine based disinfectant, offers an effective method of alleviating the adverse effects of contamination in water collection and storage vessels. Results indicated that the method is capable of significantly reducing thermo-tolerant coliform numbers to below 5 cfu/100 ml in most cases. Chlorine strength depletion after repetitive cleaning confirms the impact of process. The method does not substitute for good hygiene practices, which are essential for maintaining water quality in the household. It is suggested that the process can play an important role during outbreaks of water-borne diseases, such as cholera, particularly if combined with regular water disinfection.
Resuscitation of eleven-year VBNC Citrobacter
Authors: Dhiaf Amel , Bakhrouf Amina , Witzel Karl-Paul
Published: April 2008

Citrobacter freundii strain WA1 was stressed by incubation in seawater microcosms for eleven years. After two years of starvation, no culturable strain was observed. Incubation of samples in nutrient-rich broth medium not supplemented with growth factors, however, allowed resuscitation of VBNC cells so that subsequent plating yielded observable colonies for significantly extended periods of time. Recovery of VBNC Citrobacter freundii was obtained by incubation in nutrient broth even after eleven years of starvation. To see whether the samples contained the same strain of Citrobacter freundii inoculated 11 years ago. The complete 16S rRNA gene was PCR amplified and sequenced from initial, stressed and revived strains of Citrobacter freundii strain WA1.The 16S rRNA gene sequences from eleven-year stressed strains were homologous with a high degree of similarity to the GenBank reference strain and were identical to each other.
Catalytic Destruction of Chloramine to Nitrogen Using Chlorination and Activated Carbon—Case Study
Authors: Kochany J. , Lipczynska‐Kochany E.
Published: April 2008

The paper presents the results of laboratory and pilot studies on the removal of chloramine from potable water using chlorination with a less‐than‐breakpoint dosage of chlorine, followed by treatment with catalytic activated carbon. The effect of the chlorine‐to‐nitrogen ratio, temperature, and carbon contact time were investigated to optimize conditions for chloramines removal and minimize the production of ammonia. Results demonstrated that prechlorination of water, followed by treatment with catalytic activated carbon, can degrade monochloramine to nitrogen gas as a main product. For all chlorine‐to‐ammonia ratios studied, the observed rates of monochloramine removal were higher at a temperature of 20°C than they were at 5°C. Generation of ammonia was slightly higher at the lower temperature. However, at both temperatures, practically all monochloramine was destroyed, and only insignificant amounts of ammonia were formed when a chlorine‐to‐ammonia ratio of 7:1 was applied. The described method is simple and cost‐effective, because it eliminates the requirement of removal of ammonia, typically formed during the treatment of chloramines with activated carbon.
Bacterial Cell Monitoring in Wastewater Treatment Plants by Flow Cytometry
Authors: Manti Anita , Boi Paola , Falcioni Tania , Canonico Barbara , Ventura Alessia , Sisti Davide , Pianetti Anna , Balsamo Maria , Papa Stefano
Published: April 2008

The activated sludge process is performed by a variable and mixed community of microorganisms in an aerobic aquatic environment, in which bacteria constitute the majority and represent the main microorganisms responsible for the degradation process in a plant. In this work, we monitored bacterial charge in different wastewater treatment plants by flow cytometry, also evaluating chlorination effects on bacterial viability, both by flow cytometry and traditional plate counts. Maximum values of bacterial charge were registered in the aeration tank of all plants monitored. Cell viability did not show significant differences (p > 0.05) in samples collected in “before chlorination” and “wastewater effluent” treatment steps; this suggests that the chlorination was not able to decrease total viable bacterial charge.     In this work, we discuss the need to improve microbiological analyses, both in terms of measuring other potential pathogens and of using new methodological approaches in the traditional evaluation of the microbiological quality of effluents.
Production of Polyhydroxyalkanoate During Treatment of Tomato Cannery Wastewater
Authors: Liu Hsin‐Ying , Hall Patrizia V. , Darby Jeannie L. , Coats Erik R. , Green Peter G. , Thompson Donald E. , Loge Frank J.
Published: April 2008

Polyhydroxyalkanoate (PHA) production was achieved using tomato cannery waste coupled with a mixed microbial culture during wastewater treatment. The two‐stage PHA production process comprised a sequencing batch reactor (SBR), operating under a periodic feast–famine regime, to accomplish simultaneously wastewater treatment and selection of PHA‐accumulating microbes, followed by a batch reactor for the production of PHA‐rich biomass. The SBRs were efficient at removing soluble carbon (84%), ammonia (100%), and phosphorus (76%). Meanwhile, PHA‐accumulating microbes were enriched under the SBR operating conditions, and PHA content on a cell‐weight basis was within the range 7 to 11% in nonfiltered wastewater and 2 to 8% in filtered wastewater. Subsequently, batch studies were implemented with varying loading rates, ranging from 0.4 to 3.2 food‐to‐microorganism ratios. A maximum 20% PHA content on a cell‐weight basis was obtained. Based on the experimental results, a PHA biosynthesis‐degradation kinetic model was developed to (1) aid in the design of a pilot‐ or full‐scale PHA production process coupled with wastewater treatment and (2) determine optimal conditions for harvest of PHA‐rich biomass.
Oxidation of Polyvinylpyrrolidone and an Ethoxylate Surfactant in Phase‐Inversion Wastewater
Authors: Loraine Gregory A.
Published: April 2008

In this paper, components of an industrial wastewater that cause operational problems during biological treatment were oxidized by UV light and hydrogen peroxide (UV/H 2O 2). Preoxidation of wastewater was shown to remove polyvinylpyrrolidone (PVP) and ethoxylate surfactant and increase overall biodegradability. Several UV intensities and hydrogen peroxide concentrations were tested to find optimal conditions for the complete depolymerization of PVP in a synthetic wastewater composed of high concentrations of hydroxyl radical scavengers. To compare treatment options, absorption isotherms for PVP on granular activated carbon (GAC) in water and in the synthetic phase‐inversion wastewater matrix were determined. The data were extrapolated to estimate the cost of using UV/H 2O 2, GAC, or off‐site treatment. It was found that UV/H 2O 2 pretreatment was economically viable. Incomplete oxidation of an ethoxylate surfactant increased foaming tendency and foam stability; however, extended oxidation (>90 minutes) destroyed the foam.
Pilot‐Scale Aerated Submerged Biofilm Reactor for Organics Removal and Nitrification at Cold Temperatures
Authors: Choi Youngik , Johnson Kraig , Hayes Donald , Xu Hua
Published: April 2008

This research describes pilot‐scale experiments for efficient removal of dissolved organic and nitrogen compounds in domestic wastewater using aerated submerged biofilm (ASBF) reactors. These reactors could enhance the performance of shallow wastewater treatment lagoons through the addition of specially designed structures. The structures are designed to encourage the growth of a nitrifying bacterial biofilm on a submerged surface. They also force the direct contact of rising air bubbles against the submerged biofilm. This direct gas‐phase contact is postulated to increase the oxygen transfer rate into the biofilm and increase the microclimate mixing of water, nutrients, and waste products into and out of the biofilm. This research investigated the efficiency of dissolved organic matter and ammonia‐nitrogen removals. Specifically, the effects of cold temperatures on the dissolved organic matter and ammonia‐nitrogen performance of the ASBF pilot plant (see Figure 1) was investigated for the batch system. Over a period of 3.5 months, a total of 11 batch runs were performed. By the fourth run, the biofilm had matured to the point that it consumed all the ammonia in 40 hours. On the ninth run, the air supply was left off as a control run. This time, the ammonia was barely consumed, with the level dropping from 24 to 18 mg/L in 40 hours. By the middle of December, the average water temperature during the runs had dropped to approximately 6°C and, at one point, was as low as 3.3°C. The biofilm continued to perform even at these low temperatures, reducing ammonia levels from approximately 25 mg/L to basically zero within 40 to 48 hours.
The Power of Transnational Private Governance: Financialization and the IASB
Authors: Nölke Andreas , Perry James
Published: April 2008

This investigation of accounting standard setting as a case of business power in global governance links together three facets of power. First we examine the discursive power of international accounting standards in the ongoing process of financialization, which we break into two dynamics centered on profit and control. We argue that the selection of accounting paradigms does not concern measurement accuracy but is rather a choice of perspectives between finance and production when presenting economic reality as numbers. Drawing on evidence from the contestation between Rhenish capitalism and the financial perspective, we then explain why, despite the overwhelming structural power of finance, instrumental power exercised in political lobbying over accounting standards can still have considerable success.
The Power of Socialization: Engaging the Diamond Industry in the Kimberley Process
Authors: Kantz Carola
Published: April 2008

Research on conflict in resource-rich countries suggests that resource extraction companies contribute to tension but not development. In recent times, public-private partnerships (PPPs) have flourished, in which set up regulation is not against business but in joint cooperation with corporate actors. Yet PPPs are criticized for serving business self-interest and increasing business power rather than the common good. The paper takes the Kimberley Process and the diamond industry as an example to examine the multi-faceted nature of business power when this PPP was negotiated. The core of the argument is that realist-informed perspectives about business power in PPPs and constructivist accounts emphasizing socialization and social learning processes only tell one part of the story. While demonstrating that the diamond industry acted as a both a socializing and socialized agent, the analysis of the different facets of power shows that structural and discursive power were crucial elements in making socialization happen in the first place.
A Field Report on the Background and Processes of Privatization in Poland
Authors: Hunter Richard J. , Ryan Leo V.
Published: April 2008

This article provides a comprehensive look at the area of privatization in Poland. It provides a context and discusses the two major forces that have spurred the privatization process, as well as privatizations carried out in developing countries under the auspices of the World Bank and the IMF.The article begins with an explanation of the background to privatization in the context of state central planning, a discussion of the derivative traits of the command-and-control economy, the collapse of the system in the 1990s, the actions necessitated in society in an attempt to reform and change the system, and the reform strategies that were implement as a response to both the economic and political challenges.The article includes a discussion of the core objectives of the privatization process, the requirements of the privatization process, and an important section dealing with the actions that are necessary and complementary in preparing society and individual entities for privatization. The article concludes with an analysis of the models of privatization that were adopted in the region, along with tables delineating proceeds from privatization; the number of privatizations carried out both world-wide and in the region.
Response to Kenneth Baer and Elaine Kamarck
Authors: Miroff Bruce
Published: April 2008

A response to reviews of my book, The Liberals' Moment: The McGovern Insurgency and the Identity Crisis of the Democratic Party, written by Kenneth Baer and Elaine Kamarck.
Modelling Three-Phase Fluidized Bed Bioreactor for Wastewater Treatment
Authors: Boumehdi Toumi Leila , Fedailaine Maamar , Allia Khedidja
Published: April 2008

Economically and technically interesting, the bioreactor phenomena are studied on both micro (pore and particle size) and macro (bioreactor) levels, to describe synergetic between bio-dynamics and physicochemical dynamics. Still, the three-phase bioreactors modelling remains complex. It requires taking into account numerous factors: the pollutant biodegradation rate in the biofilm, the reactant interfacial gas-liquid and liquid-solid mass transfer, the biofilm composition and growth, the granular structure and all the transfer phenomena occurring between phases in presence. The aim of this paper is to present a model based on biofilm composition and growth, the fluidized bed structure and its hydrodynamics. The simulation results are compared with our experimental data obtained for a biological treatment, carried out in three-phase fluidized bed reactor for hydrocarbons removal from refinery wastewaters. The equipment used is laboratory scale and the obtained results show that we could degrade hydrocarbons efficiently.
Coupling between Mass Transfer and Chemical Reactions during the Absorption of CO2 in a NaHCO3-Na2CO3 Brine : Experimental and Theoretical Study
Authors: Wylock Christophe E , Colinet Pierre , Cartage Thierry , Haut Benoît
Published: April 2008

This work deals with the study of the gas-liquid mass transfer, coupled with chemical reactions. The case of carbonic gas absorption in a brine of sodium carbonate and bicarbonate is investigated. It is performed in collaboration with Solvay SA. The aim of this work is to get a better understanding of this phenomenon. It would permit an optimization of the refined sodium bicarbonate production process. The basis of developed mathematical models is presented. The CO2 absorption is coupled with several chemical reactions taking place in the liquid phase. A mathematical modelling of this coupling is first developed. The equations of the model are solved numerically, using COMSOL Multiphysics. To model the bubble-liquid mass transfer of CO2, this diffusion-reaction model is completed by a representation of the liquid phase flow around the bubble. In order to validate experimentally each scale of modelling, two experimental devices are proposed.
Hydrogen Production from Ethanol Steam Reforming: Fixed Bed Reactor Design
Authors: Giunta Pablo , Amadeo Norma , Laborde Miguel
Published: April 2008

The aim of this work is to design an ethanol steam reformer to produce a hydrogen stream capable of feeding a 60 kW PEM fuel cell applying the plug flow model, considering the presence of the catalyst bed (heterogeneous model). The Dusty-Gas Model is employed for the catalyst, since it better predicts the fluxes of a multicomponent mixture. Moreover, this model has shown to be computationally more robust than the Fickian Model. A power law-type kinetics was used. Results showed that it is possible to carry out the ethanol steam reforming in a compact device (1.66 x 10 -5 to 5.27 x 10 -5 m3). It was also observed that this process is determined by heat transfer.
A First Approach to CFD Simulation of Hydrodynamic Behaviour in a Conical Spouted Bed Contactor
Authors: Díaz Luis , Álava Isabel , Makibar Jon , Fernández Ruth , Cueva Fernando , Aguado Roberto , Olazar Martin
Published: April 2008

Spouted beds have a widespread application in the processing industry for efficient contacting of large particles with a gas. However, there is no detailed understanding of the complex behaviour of these systems, especially for fine particles, which means significant scale-up problems in industry. This paper approaches fundamental aspects of the computational fluid dynamic simulation of fine particle spouting. Using the commercial CFD simulation package Fluent (version 6.3), the spouting hydrodynamics of fine particles in a conical spouted bed is simulated and compared with experimental data.Fluent code offers a variety of models to describe the physical phenomena occurring in these kinds of reactors. In some cases, the choice is straightforward, whereas in other cases more than one option is valid a priori, and so the best one has to be selected. The main choices are the Lun et al. (1984) approach for granular kinetics and the Gidaspow model for drag force.In order to validate this selection process, model predictions are compared with experimentally observed hydrodynamic patterns, whereby CFD model parameters can be tuned. It has been proven that after this tuning, the model explains the hydrodynamic behaviour of the bed and the influence of geometric parameters and bed nature (sand, glass beads) concerning spout stability and minimum spouting velocity. Nevertheless, peak pressure drop values predicted by the model are considerably smaller than the experimental values. The model also provides reasonable predictions for spout shape, local bed voidage and air and particle velocities.
Biodegradation of High Phenol Concentration in a Membrane Bioreactor
Authors: Marrot Benoît , Barrios-Martinez Adrian , Moulin Philippe , Roche Nicolas
Published: April 2008

Phenol biodegradation by mixed culture was studied in a membrane bioreactor (MBR) over a period of 285 days. Activated sludge was used as the MBR biomass, after controlled acclimation to high phenol concentrations. The MBR permeate flux was stabilized quickly (in a few hours) and always maintained above 90 L.h-1.m-2.bar-1. The acclimatized activated sludge allowed significant phenol degradation (95% average COD removal efficiency and greater than 99% phenol removal efficiency) without supplemental reagent addition. After sludge acclimatization, the Haldane kinetics model for a single substrate was used to obtain the maximum specific growth rate (µm = 0.438 h-1), the half saturation coefficient (Ks = 29.54 mg.L-1) and the substrate inhibition constant (Ki = 72.45 mg.L-1). Biodegradation experiments were conducted at different phenol concentrations (4.9  8.5 g.L-1 d-1). Although the phenol concentration was high, the Haldane model was still acceptable, and removal capacities were in agreement with literature. Excellent effluent quality was obtained regardless of the extremely short SRT (5  17 days). This work shows the potential of MBR for toxic chemical elimination, charged effluents treatment and process stability.
Synthesis, Characterization and Kinetic Evaluation of Manganese Oxide Nanoparticles for the H2O2 Catalytic Decomposition
Authors: Delgado Vigil Manuel D , Paraguay Delgado Francisco , Collins Martínez Virginia , López Ortiz Alejandro
Published: April 2008

Nanostructured manganese oxides were synthesized towards the catalytic decomposition of hydrogen peroxide. The effect of the type of precipitant (Na2CO3 and NH4OH) over the particle size and crystallographic phase was determined. Also, the influence of particle size and crystal phase over the catalytic activity was established. Characterization of the obtained nanoparticles was performed through XRD analysis, BET surface area and TEM microscopy. Catalytic activity was followed through gasometry of the oxygen evolution [H2O2(l) ? H2O(l) + O2 (g)] at 25°C. Na2CO3 (Mn-1) and NH4OH (Mn-2) precipitants produced nanoparticles with average sizes of 5-10 nm and 20 nm, respectively. This result was attributed to higher pH stability of precipitant Na2CO3 during the synthesis process. XRD results revealed the presence of ß-MnO2, Mn5O8 and Mn3O4 crystal phase mixture for Mn-1 and Mn5O8 for Mn-2 catalyst. Catalytic activity resulted in intrinsic rate constants (kint = min-1m-2) of 5.2 and 2.3 for Mn-1 and Mn-2, respectively. The greater catalytic activity of Mn-2 catalyst was attributed to the presence of the Mn55O8 phase.
SFGP 2007 - An Analysis of the Mass Transfer in a Non-Dispersive Solvent Extraction Closed System
Authors: Albaraka Zaher , Trebouet Dominique , Tuna Marlene , Loureiro Jose Miguel , Burgard Michel
Published: April 2008

The experimental study that concerns the extraction of alkali picrates with the bis-crown-6-calix[4]arene in a hollow fibers membrane contactor, validates a dynamic model described in a previous paper [D. Trébouet, Sep. Pur. Tech., 50, 97-106, 2006]. The experimental data confirm the influence of parameters as the aqueous and organic phase flowrates and module capacity factor on the sensitivity of the system. It appears clearly that the closed extraction system operates in an unsteady state until equilibrium is reached and so only dynamic models can represent mass transfer within reasonable accuracy. The overall mass transfer coefficient is determined even in the case where the equilibrium is described by a non-linear distribution isotherm. The determination of an overall mass transfer coefficient shows that the diffusion of the metal complex in the microporous is the main limiting step of mass transfer.
SFGP 2007 - Modelling Kraft Cooking of Wood Species Mixtures
Authors: Mortha Gérard F , Jain Sandeep
Published: April 2008

A batch kraft cooking simulator has been developed with the purpose of simulating the cook of wood chip mixtures. Surveyed equations are modelling diffusion and simultaneous reactions inside a planar chip and external transfers in the outer liquor phase. Three reaction phases (initial, bulk and residual) are described by apparent first-order kinetics, affected by temperature (Arrhenius law). Cooking is controlled by reagent charges, heat-up time and plateau temperature and time. In past works, kraft modelling had been designed for batch cooks of mono-species chips. In this work, simulation was upgraded to allow the cook of chip mixtures: either mixed-size chips, according to a thickness distribution law, or mixtures of different wood species. In the latter case, initial composition, morphological characteristics and chemical kinetics are proper for each wood category. Simulation results are average parameters such as lignin content (also given as kappa number), pulp yield and residual alkali as well as chip profiles (lignin, polysaccharides and alkali), from which homogeneity indexes are calculated. The effects of thickness distribution law and oversized chips in the population are first studied. Oversized chips cook much less when they are in few numbers in a large population of small chips. This affects mean cooking results and extent of lignin distribution within chips. Studying chip mixtures from different woods focused first on the effect of morphological parameters such as wood porosity which effected delignification rates and apparent activation energies. Porosity acts on the inner-outer liquor and alkali partition, also affected by diffusion. Morphological characteristics were compared to chemical effects by varying chemical reaction activation energies. It was found that a difference of 20% on the activation energies of two woods cooking together acted dramatically on cooking results. As a consequence, lignin content and pulp yield within chips at the end of the cook were widely distributed. Finally, cooking results are more affected by chemical differences than by morphological differences, but both effects cumulate and contribute to spread lignin and polysaccharide content distributions in the final pulp.
SFGP 2007 - Microbial Growth onto Filter Media Used in Air Treatment Devices
Authors: Bonnevie Perrier Jean Chrsitophe , Le Coq Laurence , Andrès Yves , Le Cloirec Pierre
Published: April 2008

This work deals with microbial growth onto filter media and focuses on the ability of microbial communities to proliferate onto filter media. Two microorganism types are studied: microorganisms from activated sludge of wastewater treatment plant (SM) and a toluene specific consortium (TSC). The filter media considered for this study contain activated carbon fibres (ACF), combined volatile organic compounds (VOC), particles treatment purposes, activated carbon fibres felt (ACFF) and activated carbon and cellulose fibres felt (AC2F2). Using a static growth procedure during 10 days under 100 % relative humidity, artificially contaminated filters are submitted to microbial colonisation. The final concentration of microorganisms per gram of filter have been assessed using a method developed in the lab, based on filter protein content assay. The average surface charge of inocula and filter's fibres are measured to assess the influence of microorganisms adhesion on contamination. The influence of soot particles on TSC proliferation onto AC2F2 filter is then studied. Zeta measures enable the assessment of the implication of soot in microorganisms adhesion onto filter fibres. Consequences of microbial contamination on filter permeability and downstream particles released have then been assessed in a filtration device. Results demonstrate a better resistance of AC2F2 to microbial colonisation. However, SM have more difficulties to proliferate on ACFF than TSC, whereas SM colonise easier AC2F2 than TSC. Charge surface assay has defined an optimal electrostatic compatibility for TSC and AC2F2 and a minimum for SM and ACFF. When soot is added to TSC solution before introduction in AC2F2, high contamination shapes were observed whereas only a slight one occur without soot addition. Zeta potential measures show favourable charge conditions for adhesion of soot on AC2F2 fibres and TSC on soot particles. The soot may thus have played an interface role in microbial adhesion onto media. This means that electrostatic compatibility between particles is a good approach for assessing microbial adhesion onto filters but could not explain the whole mechanism of microbial proliferation. Other parameters like nutrition preferences are certainly involved. The contamination have induced filter characteristics modification. Permeability have decreased until 20 % with microbial concentration. Colonised filters have released up to 450 microbial particles/cm3. Such a release was only observed when AC2F2 was contaminated with fungi using spore as the reproduction vector (inoculum containing TSC and soot).
Pension Reform as the Triumph of Form over Substance
Authors: Kotlikoff Laurence J
Published: April 2008

This paper explains how "pension reform," as it has been practiced in Chile and elsewhere, may simply constitute a relabeling of existing fiscal institutions that end up imposing high investment and insurance fees on workers.
It's No Time to Regulate Wireless Telephony
Authors: Mayo John W
Published: April 2008

In this article, John Mayo argues that recent calls for new regulation in the wireless telephone industry do not withstand economic scrutiny.
Effect of Pranayama [Voluntary Regulated Yoga Breathing] and Yogasana [Yoga Postures] in Diabetes Mellitus (DM): A Scientific Review
Authors: Upadhyay Avnish K , Balkrishna Acharya , Upadhyay Ruchita T
Published: April 2008

Diabetes is a complex condition with a multitude of metabolic imbalances involving the regulation and utilization of insulin and glucose (sugar) in the body. Diabetes is currently considered an epidemic disease that is largely preventable and treatable through yoga. Yoga's effectiveness at preventing and treating diabetes is due to its emphasis of a healthy diet and lifestyle as well as its ability to balance the endocrine system, massage and tone the abdominal organs, stimulate the nervous and circulatory systems, and reduce stress.
Property, Liability and Market Power: The Antitrust Side of Copyright
Authors: Nicita Antonio , Ramello Giovanni B.
Published: April 2008

This paper investigates the interplay between copyright law and antitrust law in two distinct respects. We first argue that the origin of copyright seems to be rooted not only in the need to foster the production and the spread of knowledge but also in the necessity of limiting market power on the side of distributors. We then show the potential impact on market competition of the evolution of copyright as a property rule. While property rules reduce transaction costs in the standard case of bilateral monopoly over the exchange of information goods, they might increase transaction costs. When coupled with market power, a property rule enables the right holder to control uses and prices so as to implement entry deterrence strategies against potential competitors. Conversely, we argue that reversing property rules in favor of competitors or switching to liability rules for copyright may restore competitive outcomes. This conclusion brings new insights on the application of the essential facility doctrine to copyrighted works.
Comparative Study on Storage of Fruits and Vegetables in Evaporative Cool Chamber and in Ambient
Authors: Dadhich Sushmita Mukherjee , Dadhich Hemant , Verma RadhaCharan
Published: April 2008

An evaporative cool chamber was constructed with the help of baked bricks and riverbed sand. Maximum and Minimum temperature and relative humidity were recorded inside and outside the chamber for about one month. It was found that inside temperature was about 10-15°C lower than outside temperature and inside humidity was about 30-40 % higher than outside. A comparative study was made for the storage of different fruits and vegetables inside the cool chamber and in the ambient condition and their weight loss and freshness were observed everyday. It has been recorded that weight loss of fruits and vegetables kept inside the chamber was lower than those stored outside the chamber. The fruits and vegetables were fresh up to 3 to 5 days more inside the chamber than outside. The evaporative cool chamber does not require mechanical or electrical energy input and can be constructed with locally available material with unskilled labour. It is economical and can store the fruits and vegetables for 3 to 5 days with no significant loss.
Effect of Conditioning on the Production of Inulinase by Kluyveromyces marxianus var. bulgaricus through Fed-Batch Fermentation
Authors: Cazetta Marcia Luciana , Monti Rubens , Contiero Jonas
Published: April 2008

The effects of sucrose concentration, pH, temperature and aeration rate on the production of biomass and inulinase (2,1-beta-D-fructan fructanohydrolase, EC 3.2.1.7) were investigated using fed-batch fermentation by Kluyveromyces marxianus var. bulgaricus. The best sucrose concentration for enzyme activity was 10 g L-1, whereas activity was inhibited when the sucrose concentration was 20 g L-1. Enzyme activity was strongly influenced by pH of the culture. pH 5.0 was the most suitable for both enzyme activity and cell growth, achieving 98.04 U mL-1 and 14.05 g L-1, respectively, after 72 hours of cultivation. The highest production of inulinase and biomass was observed at temperatures of 25oC and 30oC, whereas a decrease in activity was observed at 35oC and 40oC. The best aeration rate was 1.0 vvm. The increase in aeration rate or oxygen injection provided no increase in enzyme activity and biomass.
A Thermomechanical Preprocessing for Pectin Isolation from Orange Peel with Optimisation by Response Surface Methodology
Authors: Rezzoug Sid-Ahmed , Maache-Rezzoug Zoulikha , Sannier Frédéric , Allaf Karim
Published: April 2008

The instantaneous controlled pressure drop process (or D.I.C process: ``Détente Instantanée Contrôlée") was used as a pre-treatment prior to pectin acid extraction from orange peel. This process involves subjecting the orange peel for a short time to steam pressure varying from 100 to 700 kPa, followed by an instantaneous decompression to vacuum at 5 kPa. Effects of processing pressure, moisture content of peels before the thermomechanical treatment and processing time were examined with response surface methodology. The optimal conditions were determined and the response surfaces were plotted from the mathematical models. The Fisher test and p-value indicated that both processing pressure and moisture content of peels before the pre-treatment had a highly significant effect on the pectin yield. The quadratic effect of processing pressure as well as the interaction effects of the initial moisture content and processing time also had a significant effect on the response. Moreover, the kinetics of pectin extraction showed that after few minutes of hydrolysis, the yields of pectin were systematically higher than that of the control sample and this is important from industrial point of view because the hydrolysis of pectin is generally performed in 10-15 minutes.
Heat Transfer Coefficient in Helical Heat Exchangers under Turbulent Flow Conditions
Authors: Coronel Pablo , Sandeep K.P.
Published: April 2008

This study involved the determination of convective heat transfer coefficient in both helical and straight tubular heat exchangers under turbulent flow conditions. The experiments were conducted in helical heat exchangers, with coils of two different curvature ratios (d/D = 0.114 and 0.078), and in straight tubular heat exchangers at various flow rates (1.89 x 10-4 - 6.31 x 10-4 m3/s) and for different end-point temperatures (92 - 149 °C). The results show that the overall heat transfer coefficient (U) in the helical heat exchanger is much higher than that in straight tubular heat exchangers. In addition, U was found to be larger in the coil of larger curvature ratio (d/D = 0.114) than in the coil of smaller curvature ratio (d/D = 0.078). The inside (hi) and outside (ho) convective heat transfer coefficients were determined based on the overall heat transfer coefficient and a correlation to compute the inside convective heat transfer coefficient (hi) as a function of NRe, NPr, and d/D was developed.
Optimisation of Cassava Pellet Processing Method
Authors: Raji AbdulGaniy O. , Kanwanya Nicholas , Sanni Lateef A. , Asiru Wahab B. , Dixon A. , Ilona Paul
Published: April 2008

Processing cassava onto pellets, an internationally acceptable and commercially rewarding cassava product minimizes quantitative and qualitative losses. Pellet samples were produced through the conventional chipping, drying, milling then pelleting with and without steaming (CDMP-S and CDMP) and modified process of grating, dewatering then pelleting and steaming (GDWP-S). Investigations for storageability, durability, uniformity in dimension and nutritional qualities resulted in pellets with moisture content of 9%, uniformly light brown in colour, free from objectionable odour with no sign of deterioration after 90 days of storage. The durability index and fine formations are 99.8% and 0.2%, 98.8% and 1.2%, 99.4% and 0.6% for CDMP-S, CDMP and GDWP-S respectively. The average lengths of 2.81, 2.23 and 2.74 cm and diameters 0.76, 0.73 and 0.67 cm respectively fall within the standard. The carbohydrate contents are 82.9%, 83.4% and 84.5% and cyanogenic glycosides contents of 14.18mg/100g, 14.32mg/100g and 10.13mg/100g respectively. The pellets produced from the modified process GDWP-S in addition to satisfying the standard colour code also conforms favourably well in terms of strength, durability and nutritional quality with the conventional CDMP-S and are better than the cold pellets from the conventional process CDMP. These are in addition to the reduction of about eight hours of chip drying operation in the modified process. This reduction in time and energy with associated quality products show that the modified process is a promising approach in the production of pellets acceptable in the export market.
Experimental Studies on Parboiling of Paddy by Ohmic-Heating
Authors: Sivashanmugam Palani , Arivazhagan M
Published: April 2008

Experimental methods of ohmic heating of parboiling of paddy have been presented. The temperature of the parboiling varied from 110 to 150 °C. Milling performance, cooking qualities and protein content of parboiled rice have been tested and it was found that these requirements are optimum at 130 °C. Milling performance of the parboiled rice by ohmic heating is better than the conventional parboiled rice. The cooking qualities of the parboiled rice are quite comparable with conventional parboiled rice.
Cross-Country Variation in Obesity Patterns among Older Americans and Europeans
Authors: Michaud Pierre-Carl , van Soest Arthur H.O. , Andreyeva Tatiana
Published: April 2008

While the fraction of obese people is not as large in Europe as in the United States, obesity is becoming an important issue in Europe as well. Using comparable data from the Survey of Health, Aging and Retirement in Europe (SHARE) and the Health and Retirement Study in the U.S. (HRS), we analyze the correlates of obesity in the population ages 50 and above, focusing on measures of energy intake and expenditure as well as socio-economic status. We find that obesity rates differ substantially on both sides of the Atlantic and across European countries, with most of the difference coming from the right tail of the weight distribution. The well-known SES gradient in the prevalence of obesity differs across countries and cannot be fully explained by the variation in food expenditure or physical activity. Obesity is associated with lack of physical activity, calorie intake, time spent on cooking, and time and money spent on eating at home and away from home, but some of these associations vary across countries. More research is needed to analyze why this is the case.
Phase Equilibria for Heterogeneous Azeotropic Distillation
Authors: Campanella Enrique A. , Mandagaran Beatriz A.
Published: April 2008

This paper discusses the importance of phase equilibrium modeling in heterogeneous azeotropic distillation. Seven ternary systems are used to examine the behavior of phase equilibria and its representation, through activity coefficient models. This work used vapor-liquid equilibrium, liquid-liquid equilibrium, vapor-liquid-liquid equilibrium, azeotropic points and residue curve data to pick up a model and its parameters with the goal that the election correlate the systems in a way that it is useful for conceptual design of heterogeneous azeotropic distillation. The paper presents results done with UNIQUAC. A procedure to obtain binary parameters is proposed. The procedure is validated through an azeotropic distillation conceptual design and its following optimization using a rigorous simulation.
Intergenerational Earnings Mobility: Changes across Cohorts in Britain
Authors: Nicoletti Cheti , Ermisch John F
Published: April 2008

The aim of this paper is to analyze intergenerational earnings mobility in Britain for cohorts of sons born between 1950 and 1972. Since there are no British surveys with information on both sons and their fathers earnings covering the above period, we consider two separate samples from the British Household Panel Survey. We combine information from the two samples using the two-sample two-stage least squares estimator described by Arellano and Meghir (1992). Our main result shows that intergenerational earnings mobility was stable for the cohorts born between 1950 and 1960 and decreased statistically significantly among more recent cohorts, those born during 19611972.
Marital Sorting, Household Labor Supply, and Intergenerational Earnings Mobility across Countries
Authors: Raaum Oddbjørn , Bratsberg Bernt , Røed Knut , Österbacka Eva , Eriksson Tor , Jäntti Markus , Naylor Robin A
Published: April 2008

We present comparable evidence on intergenerational earnings mobility for Denmark, Finland, Norway, the UK and the US, with a focus on the role of gender and marital status. We confirm that earnings mobility in the Nordic countries is typically greater than in the US and in the UK, but find that, in contrast to all other groups, for married women mobility is approximately uniform across countries when estimates are based on women's own earnings. Defining offspring outcomes in terms of family earnings, on the other hand, leads to estimates of intergenerational mobility in the Nordic countries which exceed those for the US and the UK for both men and women, single and married. Unlike in the Nordic countries, we find that married women with children and with husbands from affluent backgrounds tend to exhibit reduced labor supply in the US and the UK. In these countries, it is the combination of assortative mating and labor supply responses which weakens the association between married women's own earnings and their parents' earnings.
A Categorical Model of Cognition and Biased Decision Making
Authors: Fryer Roland , Jackson Matthew O.
Published: April 2008

There is a wealth of research demonstrating that agents process information with the aid of categories. In this paper we study this phenomenon in two parts. First, we build a model of how experiences are sorted into categories and how categorization affects decision making. Second, in a series of results that partly characterize an optimal categorization, we show that specific biases emerge from categorization. For instance, types of experiences and objects that are less frequent in the population tend to be more coarsely categorized and lumped together. As a result, decision makers make less accurate predictions when confronted with such objects. This can result in discrimination against minority groups even when there is no malevolent taste for discrimination. However, such comparative statics are highly sensitive to the particular situation; optimal categorizations can change in surprising ways. For instance, increasing a group's population, holding all else constant, can lead a decision maker to make less accurate predictions about that group.
Empirical Implications of Information Structure in Finite Extensive Form Games
Authors: Penalva Jose , Ryall Michael D
Published: April 2008

We analyze what can be inferred about a game's information structure solely from the probability distributions on action profiles generated during play; i.e., without reference to special behavioral assumptions or equilibrium concepts. Our analysis focuses on deriving payoff-independent conditions that must be met for one game form to be empirically distinguished from another. We define empirical equivalence and independence equivalence. The first describes when two game forms can never be distinguished based solely on the empirical distribution of player actions. As this turns out to be difficult to characterize, we introduce the latter, which describes two game forms that imply the same minimal sets of conditional independencies in every one of their empirical distributions. Our main contribution is to identify, for an arbitrary game form, the minimal set of conditional independencies that must arise in every one of its empirical distributions. We also introduce a new graphical device, the influence opportunity diagram of a game form which facilitates verifying independence equivalence, and hence provides a simple necessary condition for empirical equivalence.
Transverse second-harmonic generation from disordered nonlinear crystals
Authors: Fischer Robert , Saltiel Solomon , Neshev Dragomir , Krolikowski Wieslaw , Kivshar Yuri
Published: April 2008

We investigate the transverse second-harmonic generation in as grown strontium barium niobate (SBN) crystals with a random structure of anti-parallel ferroelectric domains. We consider both, single and counter-propagating pulse geometries. We investigate polarization properties of the second harmonic signal and discuss applications of this process for short pulses characterization.
Witold Żabiński (1929-2007)
Authors: Kwiecińska Barbara
Published: April 2008

Witold Żabiński (1929-2007)
Wektorowe Porządkowe Operatory Statystyczne Jako Detektory Krawędzi Obiektów W Zaszumionych Obrazach Kolorowych
Authors: Niedziela Tadeusz , Krukar Wojciech
Published: April 2008

Wektorowe Porządkowe Operatory Statystyczne Jako Detektory Krawędzi Obiektów W Zaszumionych Obrazach Kolorowych

W pracy przedstawiono przegląd najskuteczniejszych metod detekcji (wykrywania) krawędzi obiektów w obrazach kolorowych. Zaprezentowano skuteczność wektorowych operatorów porządkowych i wektorowych operatorów różnicowych oraz ich odmiany rozszerzone o różnego typu filtry. Detektory uzyskane w ten sposób są w różnym stopniu skomplikowane obliczeniowo oraz odporne na szum impulsowy i gaussowski. W przypadku operatorów DV dodanie członów filtrujących istotnie podnosi ich odporność na obecność szumu. Najlepsze wyniki ekstrakcji krawędzi w zaszumionych obrazach kolorowych uzyskano, stosując operator DV_&aL-trim.