bluuebunny/crossref_metadata_2025 huggingface dataset:
Demand and Pricing in the U.S. Margarine Industry
Authors: Kim Donghun
Published: April 2008

This paper provides estimates of U.S. demand for margarine and price-cost margins. Demand is estimated using a mixed logit model, which provides a flexible substitution pattern among products. We find that product characteristics, such as nutrient facts, package size and product forms, and household income and age composition are important determinants of demand for margarine. The estimated product-level price elasticities, which are defined as the percent change in market share corresponding to a one percent change in price, range from -1.85 to -6.34, while the cross-price elasticities vary from 0.01 to 0.98. The estimated price-cost margins vary from 28 percent to 58 percent depending on the assumption of industry conduct.
Prediction of the Viscosity of Vacuum Gas Oil-Low Density Polyethylene Blends under Varying Shear Rates, Concentrations and Temperatures
Authors: Odjo Andrew Omoniyi , Marcilla-Gomis Antonio , Martinez Rosa N , Gomez-Siurana Amparo , Garcia-Quesada Juan Carlos , Muñoz Deseada Berenguer , Garcia-Cortes Angela N
Published: April 2008

This paper is focused on the study of the viscous flow behaviour of blends of polyethylene and Vacuum Gas Oil (VGO) under dynamic shear. The application of different models for the prediction of the shear viscosity under different industrial operating conditions of shear rates, temperature and base components weight fractions has also been investigated. Viscosimetry measurements of the blends with different polymer fractions between 0 and 10 % wt., temperatures between 333 K and 433 K at shear rates up to 10000 1/s were performed. These blends were shown to have peculiar flow behaviour: exhibiting Newtonian fluid flow property at higher temperatures and lower polymer concentrations, while at lower temperatures and at higher polymer concentrations, showing non-Newtonian shear thinning or pseudo-plastic behaviour. These properties have been shown to be more pronounced at lower shear rates than at higher shear rates. As for the prediction of the blends shear viscosity under simultaneous varying shear rate, polymer weight fraction and temperature changes, a very good fit of the experimental viscosimetry data to the proposed unified Sisko-Arrhenius model has been obtained, especially considering the high number of experimental data fitted and model parameters simultaneously optimised.
Hydrodynamic Models for Packed Beds with Low Tube-to-Particle Diameter Ratio
Authors: Castillo-Araiza Carlos O. , Lopez-Isunza Felipe
Published: April 2008

In the last decade it has been a special interest to incorporate the hydrodynamics in packed bed reactor models. This seems to be important in the case of highly exothermic partial oxidation reactions normally performed in packed beds with low tube/particle diameter ratio (dt/dp< 5) because of the large void distributions in the radial and axial directions, which have a direct impact on the magnitude of radial, angular and axial profiles of the velocity field, and consequently on both, the temperature and concentration profiles in the catalytic reactor. A successful reactor model needs an adequate hydrodynamic description of the packed bed, and for this reason several models additionally incorporate empirical expressions to describe radial voidage profiles, and use viscous (Darcy) and inertial (Forchheimer) terms to account for gas-solid interactions, via Ergun's pressure drop equation. In several cases an effective viscosity parameter has also been used with the Brinkman's viscous term. The use of these various approaches introduce some uncertainty in the predicted results, as to which extent the use of a particular radial voidage expression, or the use of an effective viscosity parameter, yield reliable predictions of measured velocity profiles.In this work the predictions of radial velocity profiles in a packed bed with low tube to particle diameter ratio from six hydrodynamic models, derived from a general one, are compared. The calculations show that the use of an effective viscosity parameter to predict experimental data can be avoided, if the magnitude of the two parameters in Ergun's equation, related to viscous and inertial energy losses, are re-estimated from velocity measurements, for this particular packed bed. The predictions using both approaches adequately fit the experimental data, although the results are analyzed and discussed.
Three Phase Biofilter Model for the Removal of Styrene through the Microbial Route
Authors: Das Chhaya , Chowdhury Ranjana , Bhattacharya Pinaki
Published: April 2008

A biofilter of 0.05m diameter and 0.58m height has been studied for the removal of styrene from a simulated air-styrene mixture through the microbial route using Pseudomonas putida. Coconut coir and other waste materials have been used as the immobilization matrix for the microorganisms. Gas flow rate (0.005-0.01kgm-2s-1), micronutrient liquid flow rate (5-10 kgm-2s-1), inlet styrene concentration (0.05-1.20 gm-3) and packing size (de = 0.08 - 0.18cm) have been used as parameters. The kinetic parameters of growth rate equation of bacterial strain have been determined using batch type experimental data. A Monod type reaction model has been observed to be appropriate for the explanation of growth kinetics of the microorganisms. The values of the kinetic parameters used are Ks = 0.8gm-3, µmax = 45h-1. A three-phase deterministic mathematical model has been developed incorporating the synergistic effect of simultaneous reaction and interphase (gas to liquid to biofilm) mass transfer of styrene using experimentally determined kinetic parameters and mass transfer coefficients calculated using standard correlations. Simulated results based on the model have been compared with the experimental ones satisfactorily.
Optimization of Vapor Phase Pyridine Synthesis Hindered by Rapid Catalyst Deactivation
Authors: Kuppi Reddy Suresh Kumar Reddy , Sreedhar Inkollu , Raghavan Kondapuram Vijaya , Kulkarni Shivanand Janardan , Ramakrishna Machiraju
Published: April 2008

The synthesis of pyridine bases from acetaldehyde, formaldehyde and ammonia through aminocyclization continues to provide the best prospect for meeting growing demand. A proper selection of catalyst and standardization of process parameters are vital to achieve a market friendly product distribution and reactor operation. In this work, the major responsible factors for enhancing the activity and selectivity of HZS-5 catalysts have been identified and their individual and combined effects on aldehyde conversion, coke formation and selectivity to pyridine formation have been assessed. A priori assessment of catalyst time on stream behavior has been achieved by modeling the catalyst deactivation process.
Characterisation of Isolated Mixing Regions in a Stirred Vessel
Authors: Noui-Mehidi Mohamed Nabil , Ohmura Naoto , Wu Jie , Nguyen Bon Van , Nishioka Nami , Takigawa Teiji
Published: April 2008

An experimental study of isolated mixing regions (IMRs) in a cylindrical vessel stirred by three different impellers (a six-blade Rusthon turbine, a four-blade Lightnin A315 impeller and an axial CPE RTF4 impeller) has shown the existence of IMRs in all three systems at low Reynolds numbers. Calculations of the Re ranges in which IMRs exist, torque measurements and flow visualizations enabled the analysis of the effects of impeller type and the flow structures when IMRs were present. Particular attention was given to the case of the Rushton turbine, where digital image analysis revealed that the mechanism of IMR disappearance can be described as a period-doubling locus in the physical space, in which IMRs completely disappear at a critical Re, resulting in global mixing.
Characterization and Scale-Up of Cyanogen Bromide Chemical Activation of Sepharose CL-4B in a Stirred Tank Reactor to Purify the rHBsAg
Authors: Fernández Eutimio G , Montero José A. , Valdés Rodolfo , Arce Milagros G , Tamayo Andrés B , Geada Déborah , Medina Yenisley , Benitez Malvina , Guevara Yarysel , Ferro William , López Jorge L. , La O Maylin , Aldama Yuirisleyi , Padilla Sigifredo A , Figueroa Alejandro
Published: April 2008

The aim of this paper was to characterize and to scale-up the CNBr chemical activation of Sepharose CL-4B in a stirred tank reactor to purify the recombinant Hepatitis B surface antigen for use in vaccines. The activation quality was assessed measuring the concentration of the cyanate esters and the percentage of nitrogen in the activated matrix. The Sepharose CL-4B incorporated less than 50% of the initial CNBr amount added to the matrix, but the monoclonal antibody CB.Hep-1, used as immunoligand to purify the rHBsAg, was efficiently immobilized in a weakly activated matrix (<8 ?mol/mL of matrix). The impellent type has a significant influence on activated matrix quality. The constant power per volume unit was a proper criterion to scale-up the Sepharose CL-4B March's modified chemical activation procedure with CNBr.
SFGP 2007 - The Effects of Sludge Digester Biogas Recovery on WWTP Ecological Impacts and Exergetic Balance
Authors: Belhani Mehdi , Pons Marie-Noëlle , Alonso Dominique
Published: April 2008

Exergetic Life Cycle Assessment (ELCA) is applied to a wastewater treatment plant (WWTP) by activated sludge in order to demonstrate the environmental and exergetic effect of biogas recovery within the whole system boundaries. Two methods of recovery are compared: a simple burner (Burner scenario) and a combined heat and power engine (CHP scenario). The results showed that biogas recovery reduces the depletion of natural resources and decreases ecological impacts. Eutrophication, toxicity and ecotoxicity impacts are not affected by biogas recovery in the Burner scenario and the change is not significant in the CHP scenario. Irreversibility is added to the system by biogas recovery. This is because of the nature of the burnt mixture, which is different from conventional fossil fuel and because of the addition of units such as CHP and heat exchangers. The CHP fed with the biogas cannot fulfill the total demand in thermal energy for heating and drying in comparison to the burner. Natural gas should be burnt additionally and a heat exchanger introduced. The irreversibility of the CHP scenario is larger than the Burner's one, but the former allows reducing electricity consumption by 22.7%. Moreover, exhaust gas has a positive effect from the exergy point of view. It contains an excess potential work which could be recovered in another function. Based on ozone layer depletion, photochemical oxidation, acidification and marine aquatic ecotoxicity impacts, biogas recovery with a CHP scenario is better than with a Burner scenario. But based on abiotic resources depletion, global warming potential, irreversibility and excess potential work the second strategy, with a Burner scenario, is the best one. In process optimization, the focus should not be only on potential impacts reduction. The decrease of the irreversibility produced by new functions introduced in the system should also be taken into account. The other subsystems within the system boundaries should be looked at especially those related to electricity production. The ELCA is a useful tool for system ecodesign and for finding the best way to promote renewable fuels versus fossil ones.
Desulfurization of FCC Gasoline: Novel Catalytic Processes with Zeolites
Authors: Jaimes Lisette , Tonetto Gabriela M. , Ferreira María Lujan , de Lasa Hugo
Published: April 2008

New regulations aim to achieve a drastic sulfur emission reduction in fuels and impose very low sulfur concentration caps (30 ppm in gasoline and 15 ppm in diesel) that will be in full force in 2009. FCC gasoline represents almost 40% of the total gasoline pool and it is the major sulfur contributor, with up to 8595%. To deal with this situation, most refiners have adopted post-treating FCC gasoline processes given they are more viable and less costly for meeting sulfur environmental regulation limits. In this respect, one should notice that conventional hydro-treating of FCC gasoline removes sulfur decreasing gasoline quality with octane number losses. The use of hydrogen also adds important costs to the desulfurization. As a result, new promising catalytic desulfurization processes are being proposed using zeolites as adsorbents/catalysts. These new approaches may lead to novel technologies, for example, with the case of gasoline de-hydrosulfidation with no hydrogen addition and alternatively to adsorption processes with co-feeding of an H-donor being pioneered at CREC University of Western Ontario. In both approaches sulfur is efficiently removed leaving the gasoline octane number index intact. The zeolite structure, the framework composition and the properties of the charge compensating cations are all parameters with major impact on catalytic desulfurization. In particular, shape selectivity is expected to play an important role in determining product selectivity when condensation reactions are significant. In this respect, the H-ZSM5 zeolite appears to have the adequate balance of Brönsted acidity and Lewis basicity to efficiently convert thiophene to H2S, with minimal transformation of benzothiophene and oligomers into coke. From a chemical reactor engineering point of view, novel gasoline desulfurization can be implemented using both fixed and fluidized bed reactors. Fluidized circulating bed reactors display high sulfur removal ability allowing frequent catalyst removal from the catalytic bed and coke combustion in a twin fluidized regeneration unit. Fixed bed units with adsorption/desorption cycles, used in conjunction with and without H donor co-reactants, lead to selective adsorption and efficient removal of sulfur species.
A Direct Electrode-Driven Immobilized Catalase for Biocatalysis of Peroxides
Authors: Liu Huihong , Huang Xue-Ling , Wang Qi-Hui
Published: April 2008

The direct electrochemistry of catalase (Cat) immobilized in agarose hydrogel film on glassy carbon (GC) electrode was investigated. A pair of well-defined and quasi-reversible redox peaks both in aqueous buffer and ethanol-aqueous mixture was obtained. The formal potential (E°') indicates the reactions origin from the direct electron transfer between the CatFe(III)/(II) couple and the electrode surface. The E°' is linearly dependent on solution pH (redox Bohr effect), indicating the electron transfer of the CatFe(III)/(II) redox couple accompanied with the transfer of a proton. The electron transfer can be facilitated in ethanol-aqueous mixture for the reason of partial dehydration of the distal heme pocket. The water pools in agarose hydrogel play an important role in preventing either the change of conformation or the inactivity of Cat from polar organic solvent. Cat retains its original conformation in the agarose film that was confirmed by UV-Vis spectra and electrochemical behaviors in comparison to the controlled experiments using free hemin. The catalytic reactions to peroxides (hydrogen peroxide, cumene hydroperoxide, t-butyl hydroperoxide, 2-butanone peroxide) using Cat-agarose modified electrode were also explored both in aqueous buffer and ethanol-aqueous mixture. The method could be application to the preparation of the hydrogel based third generation biosensors or bioreactors in organic media.
SFGP 2007 - Ultrafine Aerosol Generation from Free Falling Nanopowders: Experiments and Numerical Modelling
Authors: Ibaseta Nelson , Climent Eric , Biscans Béatrice
Published: April 2008

In the last few years, the interest on nanomaterials and their applications have increased in a considerable way. Hence, the knowledge of the possible hazards on human health becomes necessary. Besides the description of the toxicological effects of nanomaterials, the exposure level on the worksites is one of the key data of the problem. The present work aims at studying the resuspension of ultrafine particles in the air during the falling of nanostructured powders.A numerical approach has been developed aiming at simulating the free falling of a powder cluster. The results show that a resuspension of particles occurs following the powder cluster deformation during the free fall of the particles in the air. Isolated particles remain suspended in the air for a long time.Free falling experiences have been carried out in a 180*50*80 cm chamber with TiO2 and SiO2 nanostructured powders. An Electric Low Pressure Impactor (ELPI) has been used for measuring the particle number concentration as well as the size distribution of the generated aerosols (particle suspension in the air). The agglomerates constituting the original powder were resuspendend in the air. The presence of ultrafine aggregates of TiO2 and SiO2 nanoparticles in the air has been checked by ELPI measurements and SEM visualizations of the ELPI stages. The aerosol size distribution is bimodal with two populations, concerning a micrometric nanostructured agglomerates, and ultrafine aggregates coming from micrometric agglomerates break-up. The influence of the height of the fall upon the aerosol concentration is significant. However, the aerosol size distribution remains roughly constant for a given powder, independently of the height of the fall.
SFGP 2007 -- A New Concept for the Abatement of Volatile Organic Compounds by a Two-Stage Process Combining Non-Thermal Plasma Treatment and Filtration
Authors: Ognier Stephanie , Youssef Joseph , Cavadias Simeon , Amouroux Jacques
Published: April 2008

A new process combining non-thermal plasma treatment and filtration has been studied for the treatment of diluted gaseous effluents containing VOCs. The removal of a VOC model molecule, beta-pinene, in air was studied. The results showed that the pollutant was chemically modified by soft oxidation reactions in the plasma treatment step and that the resulting products could be trapped on a filter with high efficiency. As a result, the process was less energy-consuming compared to complete oxidation. The pollutant could be injected before or after the discharge zone without affecting the performance of the process. Nopinone, identified by GC-MS analyses, is the main product of the plasma treatment step. It was hypothesized that this product results from the oxidation of beta-pinene by 'excited' ozone produced by the discharge and the destruction of beta-pinene. The product was therefore modelled by a second-order reaction between beta-pinene and ozone. In the second part of this work, a semi-industrial scale pilot capable of treating a gas flowrate of 50 m3/h was built. The pilot was designed with the assistance of process simulations made by coupling a flow model (obtained by a CFD code) and the previous kinetic model. The results show that the performances of the pilot measured experimentally were in agreement with the predicted ones.
Hedge Fund Wizards
Authors: Foster Dean P. , Young H. Peyton
Published: April 2008

Dean Foster and Peyton Young explain a dramatic problem in the hedge fund industry that allows hedge fund managers to profit hugely while exposing their investors to great unknown risks.
Subprime Borrowers Deserve an Own to Rent Transition
Authors: Baker Dean
Published: April 2008

Millions were persuaded to buy homes in the middle of a housing bubble. Many will be forced to give up ownership, but an "own to rent" policy can keep them in their home, according to Dean Baker.
Effects of Harungana madagascariensis Stem Bark Extract on the Antioxidant Markers in Alloxan Induced Diabetic and Carrageenan Induced Inflammatory Disorders in Rats
Authors: Iwalewa Ezekiel. Olugbenga , Adewale Isaac O , Taiwo Bamigboye J , Arogundade Tope , Osinowo Ade , Daniyan Oluwatoyin M , Adetogun Gbade E
Published: April 2008

The complimentary antioxidant and anti-inflammatory effects of Harungana madagascariensis stem-bark ethanolic extract on the reactive oxygen species (ROS) markers induced in the pathogenesis of diabetes mellitus and carrageenan-induced oedema were examined. The study was carried out on normal and alloxan induced diabetic rats. Oedema was induced by injecting 0.1mL of 1% carrageenan suspension in the right hind paw of rats. The Glutathione (GSH), Lipid peroxidation, Superoxide dismutase (SOD) and Catalase (CAT) were estimated by standard spectrophotometric methods, while the anti-inflammatory effect was evaluated using plethysmometer. The antioxidant activity was estimated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) photometric assay techniques. Administration of ethanolic extract of Harungana madagascariensis stem bark was found to reduce glucose level in diabetic animals and oedema size formation in the right hind paw of rats. Radical scavenging capacity was exhibited by increase in reduced glutathione (GSH) and a decrease in the concentrations of malondialdehyde (MDA) in alloxan-induced diabetic rats (in vivo) and against DPPH (in-vitro). The antidiabetic, antioxidant and anti-inflammatory activities of the plant extract could be complementary by reducing the high levels of inflammatory and oxidative stress markers, which have been associated with the diabetic condition. These could possibly explain the ways the plant produce its effects against diabetic conditions.
Comparison of Available Silicone Rubber Coatings for High Voltage Applications
Authors: Sanaye-Pasand Majid , Naderian Jahromi Ali , El-Hag Ayman H , Jayaram Shesha H
Published: April 2008

This paper presents the results of an investigation on evaluating room-temperature-vulcanized (RTV) silicone rubber coatings for high-voltage insulators of substations and overhead transmission lines. It is based on tests conducted for three different available RTVs that are currently used by utilities. The study compared three commercial coatings: RTV-A and RTV-B filled with ATH (aluminum tri-hydrate) as the primary filler, and RTV-C filled with silica. The relative comparison between them is based on their electrical and chemical characteristics. The evaluation employed standard and research-based evaluation methods, including the salt fog test, the inclined plane test, thermo-gravimetric analyses (TGA), thermal conductivity measurement, soaking in water, the mechanical test, and SEM photographs. Results of the inclined plane test showed that the silica-filled coating is not resistive against tracking and erosion compared with ATH-filled coatings. It was observed that filler size is one of the main reasons for better performance of RTV-A compared with RTV-B, whereas both have ATH as the primary filler. The higher thermal conductivity of RTV-A resulted in a very good performance in the salt fog test and the IPT.
DSP Based Induction Generator Controller for Single Phase Self Excited Induction Generator
Authors: Palwalia Dheeraj Kumar , Singh S. P.
Published: April 2008

This paper presents the design and implementation of a digital signal processor (DSP) based induction generator controller (IGC) to regulate the voltage and frequency of a single phase self excited induction generator (SEIG), suitable for stand alone power mode employing unregulated turbine such as micro-hydro power generation. The developed prototype model of a DSP based SEIG-IGC system is cost effective, reliable, flexible and capable of network based application for remote configuration with TCP/IP stack. The transient behavior of the developed DSP based SEIG-IGC system at different operating conditions such as the application and removal of static (resistive and reactive) and dynamic (single phase induction motor) load is investigated to demonstrate the capabilities of the proposed IGC.
The Singer or the Song? Developments in Performers' Rights from the Perspective of a Cultural Economist
Authors: Towse Ruth
Published: April 2008

Over the last century, performers gradually acquired statutory protection of their economic and moral rights. These rights are not copyright in the legal sense but neighboring rights and until recently, they were mainly remuneration rights that are collectively administered. With the WPPT (WIPO Performers and Phonograms Treaty), performers now have individual exclusive rights for digital performances; this leads to the question: what has motivated this change – is it a change in the perception of the value of performer or a change brought about by the changing technology of copying or, indeed, a change that reflects different economic costs and benefits? The paper discusses the role of copyright law as an incentive to performers and asks if the economic role of the performer is so different from that of the author. The conclusion is that a complex interaction of the legal regulations, economic conditions and institutional arrangements for administering these new rights will determine the outcome.
Evaluation of Technological Characteristics of Some Varieties of Sorghum (Sorghum Bicolor) Cultivated in the Soudanosahelian Zone of Cameroon
Authors: Roger Djoulde Darman , Richard Kenga , François-Xavier Etoa
Published: April 2008

Some varieties of sorghum (Sorgum bicolor) available in the North of Cameroon have been characterized for to their ability to meet consumers and industries requirements. Local varieties of sorghum, namely ``Zouaye," ``Djigari," ``Damougari" have been compared to four selected varieties with good agronomic characteristics (S35, CS-210, CS-95, CS-54). Results indicate that the varieties CS-95, CS-54, and ``Madjeru" present very high percentages of cut brown grains with a variation from 48% to 87%. The variety ``Dmougari" seems harder than the others with a PSI of 19±2.6. Varieties CS-210 and CS-95 appear to be most tender with successive PSI of 11.8±5.21 and 12.2±1.2. All local varieties (Madjeru, Zouaye, Damougari, Djigari) have shown a 1000-kernel weight ranging between 21.9±2.6g and 25.5±1.5g, whereas selected varieties (S35, CS-210, CS-95, CS-54) present 1000-kernel weight binds between 15.43 ±2.5g and 19.31±5.21 g. The majority of the studied grains present an index of vitrosity between 1.6 and 4.85, except CS-210, Madjeru, Djigari which are semi-vitreous (with indices of vitrosity ranging between 3 and 4. Dihurin content of all varieties ranges from 108±15 to 225±23 (ppm). The colour of the grain shows that the improved varieties present yellow blades and yellow ivory colours, whereas the local varieties are brown and red.
Equilibrium Moisture Content Models for Lafun
Authors: Oyelade Olusegun J
Published: April 2008

Insights into the relationship between the air relative humidity (water activity (aw)) and equilibrium moisture content of food materials is essential to maintain good keeping quality and optimize process operation. The adsorption isotherms for cassava flour (lafun) were investigated with the static gravimetric method. Concentrated acid (H2SO4) solutions were used to vary the micro-climate in the study and presented in an easy-to-use template-like format over the range of temperature (27- 40oC) and aw (0.10-0.80) usually experienced in the tropical environment. The experimental data were compared with five widely recommended models in the literature for food sorption isotherms (GAB, modified GAB, modified Oswin, modified Henderson & modified Chung-Pfost). The moisture sorption isotherms were sigmoidal in shape and were influenced by temperature. The modified Oswin model was found to be most adequate whilst the modified GAB appears not suitable to model the adsorption isotherms for lafun.
Fatty Acid Composition of Turkey Meat Sucuk (Soudjuck), Salami, and Sausages
Authors: Otles Semih , Cagindi Ozlem
Published: April 2008

In this paper, the fatty acid composition of turkey meat sucuk (soudjuck), salami, and sausages were determined and compared with each other. The fatty acids methyl esters of each product were identified by capillary gas chromatography. Most of the fatty acids in sucuk (soudjuck) samples were monosaturated; however in salami and sausages samples most of were mono and di-unsaturated. Saturated fatty acids in sucuk (soudjuck) samples followed, having the palmitic and stearic acids as their major components and had a range of 229.7-385.2 g kg-1 and 87.6-215.9 g kg-1. In salami and sausages samples, unsaturated fatty acids, the oleic and linoleic acids were the major components and had a range of 170.0-542.0 g kg-1 and 151.5-353.0 g kg-1. PUFA (polyunsaturated fatty acids) were found for sausages in the highest amount with linoleic acids concentration. Turkey meat salami and sausages presented a higher content of unsaturated and polyunsaturated fatty acids than turkey meat sucuk (soudjuck).
Modelling and Simulation Heat Transfer in Wheat Stored in a Simulated Sealed Pit
Authors: Ismail Mohamed A. , Douglass Michael P. , Stenning Brian C.
Published: April 2008

A mathematical model was developed to predict the change of temperature distribution with time in the radial and axial directions in a simulated sealed cylindrical pit. The finite difference method was used in the model to calculate the conductive heat transfer. The model predicts the grain temperatures in the pit during the storage period using input data of initial grain temperature, storage time and number of spatial elements in both radial and axial directions. Other input data include the finite difference spatial increment in both directions, the finite time increment, temperatures of soil surrounding the pit and the physical properties of grain, pit wall material and surrounding soil. To validate the model, predicted temperatures were compared with measured data for wheat of Apollo variety being stored in a simulated sealed pit for a period of 70 days. The wheat was stored in a cylindrical mild steel tank with 0.6 m in both diameter and height. The initial uniform grain temperature was 15°C and the initial uniform grain moisture content was 12.45% (w.b.). Both measured and predicted wheat temperatures attained steady state within a short period of storage (2 to 6 days) and this equilibrium was maintained throughout the experiment period. At the end of the storage period, the grain temperatures were decreased by an average of 2.63°C and the grain moisture contents were increased by an average of 1.62% (w.b.) at the top layer of the pit. For the bottom layer of the pit, the grain temperatures increased by an average of 7.04°C and the grain moisture contents were decreased by an average of 0.50% (w.b.) The conductive heat transfer model predicted the grain temperatures with a standard error of estimate between measured and predicted of 0.12°C -0.25°C.
Use of Natural Coagulants of Plant Origin in Production of Soycurd (Tofu)
Authors: Sanjay K R , Subramanian R. , Senthil Amudha , Vijayalakshmi G.
Published: April 2008

Tofu  Soycurd, is one of the important non-fermented soybean products, which has been widely used in a variety of dishes by oriental people for many centuries. Normally in the preparation of Tofu, synthetic coagulants such as calcium sulphate, magnesium chloride, Glucono-?-lactone, etc., are used. These coagulants are not readily available sometimes for use in the household and not available easily in the rural areas. Hence, an attempt was made to use natural coagulants of plant origin (Citrus lemon, Garcinia indica, Tamarindus indica, Averrhoa carambola, Averrhoa bilumbi, Phyllanthus distichus, Tamarindus indica flower extract, Hibiscus canabinus and Passiflora edulis) in preparation of Tofu. Yield, texture, proximate composition and sensory quality of Tofu prepared using natural coagulants were analyzed and a comparative evaluation was made between Tofu obtained from synthetic coagulants. Results showed that use of natural coagulants in preparation of Tofu increased the yield (24.5g/100 ml of soymilk). Total crude protein estimation revealed that the protein content in Tofu prepared using natural coagulants was comparatively higher than the synthetic coagulants (61.4% on dry weight basis). Texture analysis results of Tofu prepared using different coagulants showed that Garcinia indica extract produced Tofu with hard texture, more cohesiveness and chewiness compare to other coagulants followed by Calcium sulfate and Tamrindus indica. Sensory analysis of Tofu showed Citrus lemon extract produced best Tofu with higher overall quality in terms of appearance, texture, taste, flavor and color followed by Tamarindus indica.
Large Health Savings Accounts: A Step toward Tax Neutrality for Health Care
Authors: Cannon Michael F.
Published: April 2008

The creation of tax-free health savings accounts presents a new opportunity to reduce the distortions created by federal tax preferences for health-related expenditures that ultimately could help eliminate those distortions. This paper proposes changes to current law that would allow most workers to receive the full amount that they and their employer spend on their health benefits as a tax-free cash contribution to the worker's health savings account. Restructuring the exclusion for employer-sponsored health benefits in this way would enable more individuals to obtain health insurance that matches their preferences, would increase efficiency in the health care sector, and could reduce inequities created by the exclusion. These changes also offer a means of limiting the currently unlimited tax exclusion for employer-sponsored health benefits that may be more politically feasible than past proposals.
Hospital Quality and Selective Contracting: Evidence from Kidney Transplantation
Authors: Howard David H.
Published: April 2008

Most private health insurers offer a limited network of providers to enrollees. Critics have questioned whether selective contracting benefits patients. Plans counter that they take quality into account when choosing providers. Using data on five plans' networks for kidney transplant hospitals, this study shows that in-network hospitals have better outcomes than out-of-network facilities. Conditional logit estimates using patient level data confirm this result: compared to Medicare patients, privately-insured patients are more likely to register at hospitals with higher survival rates. Restricting choice has the potential to improve patient welfare if plans steer uninformed patients to high quality hospitals and physicians.
Does Imagery Work? Effects on Performance and Mental Skills
Authors: Weinberg Robert
Published: April 2008

This paper provides a review of the literature on the relationship between imagery and sport performance as well as between imagery and the development of mental skills. First, the many anecdotal reports of imagery effectiveness are noted and a definition is provided focusing on the multidimensional nature of imagery. The evidence of the enhancing influence of imagery on sport performance is then examined by looking at the early studies (mental practice), case studies, preparatory imagery, imagery used as part of a mental training package, and the use of imagery by successful athletes. After discussing the limitations in research imagery relating to performance, the focus turned to the relationship of imagery and the development of mental skills (e.g., confidence, dealing with pressure, motivation). Factors affecting imagery effectiveness were highlighted including imagery perspective, type of task, positive versus negative imagery, and timing of imagery. The paper concluded with future directions for research including such areas as amount of time to image, imagery and children, imagery ability, and imagery and performance expertise.
Performance of Statistical Process Control Tools under Different Plant Operation Strategies
Authors: Maestri Mauricio L. , Cassanello Miryan C. , Horowitz Gabriel I.
Published: April 2008

The outputs of statistical process control (SPC) tools developed for fault detection are comparatively examined while applied to actual data collected in an industrial plant. The influence of added information gathered from the plant operation under different strategies is analyzed. Particularly, standard principal component analysis (PCA), kernel PCA and the Hotelling's T2 charts are inspected for a reported problem. The effect of training the tools either with an extended historic databank obtained under standard operation, or including also non-conventional conditions, is studied. The ability of the tools to provide a specific alarm and identify the responsible variable is examined by analyzing the contributions per variable to the SPE and the T2 statistics. In addition, the capacity of the tested tools to adapt to a new operation strategy is compared.
Fluid Catalytic Cracking Riser Modeling in Heat Transfer Mode
Authors: Gupta Raj Kumar , Kumar Vineet
Published: April 2008

A 3-phase, one dimensional, heat transfer model for the fluid catalytic cracking riser reactor is developed. This model incorporates a new detailed kinetic model based on pseudo components' cracking. The model also includes the effect of local temperature on the reaction rate constants, variation of endothermic heat of cracking all along the riser height, and the heat of adsorption of the coke on the catalyst. Also, the developed model is compared with a 2-phase, one dimensional heat transfer model.The proposed model is capable of predicting the products' yields, phase temperatures, and phase velocities all along the riser height. Model predictions are very close to the data reported in literature.
Investigation and Modeling of Splashing in the Peirce Smith Converter
Authors: Hasanzadeh - Lileh Koohi Ali , Halali Mohammad , Askari Masoud , Manzari Mehrdad T.
Published: April 2008

To investigate the factors affecting splashing in Peirce-Smith copper converters of Sarcheshmeh copper complex, South-East Iran, a laboratory scale model with dimensions one eighth of the actual converter was designed and assembled. The model was filled with water. Air was impinged onto the water. The sequence of events was subsequently recorded using high speed cameras. Factors affecting splashing such as blowing angle, volumetric flow rate of air, and the distance of the blowers from water surface were studied.Using a value of 2.65×10-11 for Morton dimensionless number, it was found that splashing may be reduced by 75% if the air speed in the tuyeres is reduced from 155 m/s to 30 m/s while the nozzle distance from the melt free surface is between 2 to 0.5 meters.
Incompatibility, Product Attributes and Consumer Welfare: Evidence from ATMs
Authors: Knittel Christopher R. , Stango Victor
Published: April 2008

Incompatibility in markets with network effects reduces consumers' ability to "mix and match" components offered by different sellers, but can also spur changes in product attributes that might benefit consumers. In this paper, we estimate the effects of incompatibility on consumers in a classic hardware/software market: ATM cards and machines. We find that ATM fees ceteris paribus reduce the network benefit from other banks' ATMs. However, a surge in ATM deployment accompanies the shift to surcharging. Even under conservative assumptions regarding how much of the surge is directly attributable to surcharging, greater deployment often completely offsets the harm from higher fees. The results suggest that policy discussions of incompatibility must consider not only its direct effect on consumers, but also its effect on product attributes.
Children of the Post-Communist Transition: Age at the Time of the Parents' Job Loss and Dropping Out of Secondary School
Authors: Kertesi Gabor , Kezdi Gabor
Published: April 2008

Using data on children whose parents lost their jobs during the post-communist transition of Hungary, we address the causal effect of unexpected long-term unemployment of parents on their children's educational achievement. We estimate the effect of the children's age at the time of their parents' job loss on their probability of dropping out of secondary school (an event that follows the parents' job loss by many years). The treatment is an additional year reared in a family with regularly employed parents, which can be interpreted as additional human capital investment. We provide bounding estimates to the causal effect. The estimated bounds are tight, they show a substantial effect, and the effect is significantly stronger for preschool age children than for older ones.
How Did SCHIP Affect the Insurance Coverage of Immigrant Children?
Authors: Buchmueller Thomas C , Lo Sasso Anthony T , Wong Kathleen N
Published: April 2008

The State Children's Health Insurance Program (SCHIP) significantly expanded public insurance eligibility and coverage for children in ``working poor" families. Despite this success, it is estimated that over 6 million children who are eligible for public insurance remain uninsured. An important first step for designing strategies to increase enrollment of eligible but uninsured children is to determine how the take-up of public coverage varies within the population. Because of their low rates of insurance coverage and unique enrollment barriers, children of immigrants are an especially important group to consider. We compare the effect of SCHIP eligibility on the insurance coverage of children of foreign-born and native-born parents. In contrast to research on the earlier Medicaid expansions, we find similar take-up rates for the two groups. This suggests that state outreach strategies were not only effective at increasing take-up overall, but were successful in reducing disparities in access to coverage.
The Effect of the Consolidated Omnibus Reconciliation Act of 1985 on Health Care Utilization of Employment Separators
Authors: Zimmer David M.
Published: April 2008

This paper uses data from the Medical Expenditure Panel Survey to estimate the effect of COBRA on health care utilization among a sample of individuals who experience employment separation. The empirical specification employs a structural simultaneous equations model of insurance choice and utilization that is estimated by Maximum Simulated Likelihood. Results indicate that employment separators who elect COBRA appear to consume more health care compared to individuals who become temporarily uninsured. In addition, results do not indicate adverse selection into COBRA. Although COBRA enrollees consume more health care than temporary insurance losers, election appears to exhibit favorable selection with respect to physician utilization.
Sequential Patterns of Drug Use Initiation - Can We Believe In the Gateway Theory?
Authors: Bretteville-Jensen Anne L , Melberg Hans O , Jones Andrew M
Published: April 2008

The gateway, or stepping stone, hypothesis is important as it has had considerable influence on drug policy and legislation in many countries. The gateway hypothesis offers one possible explanation for young people's development of serious drug problems. It simply states that the use of one drug increases the risk of starting to consume another, possibly more harmful, drug later on and that the risk increases with frequency of use (dose-response). The empirical basis for the hypothesis is the common finding that most heavy drug users have started with less dangerous drugs first and that there seems to be a "staircase" from alcohol and solvents via cannabis and tablets to amphetamine, cocaine and heroin. The core question is whether the sequential initiation pattern of drug use is best explained by the gateway hypothesis or whether the phenomenon is better understood by employing the concepts of accessibility and/or transition proneness? Based on unique data from a representative sample of 21-30 year olds in Oslo we have examined the gateway effect of both legal (alcohol) and illegal drugs (cannabis) on subsequent use of cannabis and hard drugs (amphetamine and cocaine). We are the first to use multivariate probit models to examine the hypothesis. The models take into account unobservable individual-specific effects to reduce the possibility of a spurious effect of soft drug use on the onset of hard drug use. The gateway effects are greater when we do not take account of unobserved heterogeneity, but, although substantially reduced, they remain considerable when unobserved factors are accounted for.
Resources for Sale: Corruption, Democracy and the Natural Resource Curse
Authors: Bulte Erwin , Damania Richard
Published: April 2008

A puzzling piece of empirical evidence suggests that resource-abundant countries tend to grow slower than their resource-poor counterparts. We attempt to explain this phenomenon by developing a lobbying game in which rent seeking firms interact with corrupt governments. The presence or absence of political competition, as well as the potential costs of political transitions, turn out to be key elements in generating the 'resource curse.' These variables define the degree of freedom that incumbent governments have in pursuing development policies that maximize surplus in the lobbying game, but put the economy off its optimal path.
The Full Surplus Extraction Theorem with Hidden Actions
Authors: Obara Ichiro
Published: April 2008

Consider a situation in which a principal commits to a mechanism first and then agents choose unobservable actions before their payoff-relevant types are realized. The agents' actions may affect not only their payoffs directly but also the distribution of their types as well. This paper extends Crémer and McLean's full surplus extraction theorem to such a setting. In this environment, it is shown that a principal may not succeed in extracting full surplus from agents when there are many actions to which the agents can deviate.However, it is also shown that a principal can extract full surplus generically given any approximately efficient (completely) mixed action profile. This is achieved by using a general mechanism where agents announce both their types and their realized actions. Therefore, with hidden actions, there is a big gap between exact full surplus extraction and approximate full surplus extraction.
Forgiving-Proof Equilibrium in Infinitely Repeated Games
Authors: Aramendia Miguel , Ruiz Luis , Wen Quan
Published: April 2008

In repeated games, equilibrium often requires that any deviation be punished in the continuation, regardless of whether it is beneficial to the other players. It seems against the nature of non-cooperative game theory for the other players to decide what to do based on what one player did, rather than on the well-being of themselves. We introduce a new solution concept called a forgiving-proof equilibrium that recommends continuing as if nothing had happened after a player deviates without harming the others. A folk theorem is established to characterize the set of forgiving-proof equilibrium payoffs when players are sufficiently patient. The concept of forgiving-proof equilibrium significantly reduces the set of equilibrium outcomes in many repeated games.
An Unhappy Consensus: EU Membership and Party Collusion in Hungary
Authors: Mike Károly
Published: April 2008

The article explores the roots and dynamics of political consensus on EU membership in Hungary. Employing a principal-agent theory of the political process, it emphasises the role of various forms of competition in the healthy functioning of a representative democracy. An informal discussion of the Hungarian case is followed by a game theoretical model of party collusion under circumstances when a new political dimension offers an opportunity for political representatives to weaken electoral control. A key lesson of the empirical findings as well as the formal model is that collusion among political representatives within individual nation states and collusion among states may, under specific circumstances, reinforce each other.
Class Is Not Dead - It Has Been Buried Alive: Class Voting and Cultural Voting in Postwar Western Societies (1956-1990)
Authors: van der Waal Jeroen , Achterberg Peter , Houtman Dick
Published: April 2008

By means of a re-analysis of the most relevant data source  the International Social Mobility and Politics File  this paper criticizes the newly grown consensus in political sociology that class voting has declined since World War II. An increase in crosscutting cultural voting, rooted in educational differences, rather than a decline in class voting proves responsible for the decline of traditional class-party alignments. Moreover, income differences have not become less, but more consequential for voting behavior during this period. It is concluded that the new consensus has been built on quicksand. Class is not dead  it has been buried alive under the increasing weight of cultural voting, systematically misinterpreted as a decline in class voting, due to the widespread application of the so-called Alford index.