bluuebunny/crossref_metadata_2025 huggingface dataset:
Latest advances in substrates for flexible electronics
Authors: MacDonald W. A. , Looney M. K. , MacKerron D. , Eveson R. , Adam R. , Hashimoto K. , Rakos K.
Published: November 2007

Abstract— Recent advances in both organic‐ and inorganic‐based electronics processed on flexible substrates offer substantial rewards in terms of being able to develop displays that are thinner, lighter, robust, and conformable, and can be rolled away when not required. In addition, plastic‐based substrates coupled with the recent developments in solution deposition and ink‐jet printing for laying down OLED materials and active‐matrix thin‐film‐transistor (TFT) arrays open up the possibility of cost‐effective processing in high volumes using roll to roll (R2R) processing. To replace glass, however, a plastic substrate needs to be able to offer some or all of the properties of glass, i.e., clarity, dimensional stability, thermal stability, barrier, solvent resistance, and low coefficient of thermal expansion (CTE) coupled with a smooth surface. In addition, a conductive layer may be required. No plastic film offers all these properties so any plastic‐based substrate will almost certainly be a multilayer composite structure. This paper will discuss the issues associated with selecting plastic materials, contrast the various options, and highlight how to gain optimum performance through process control. This will be illustrated with examples of film in use in flexible electronic applications.
An averaging pixel structure using microcrystalline‐silicon films prepared at high temperature for AMOLED displays
Authors: Gaillard Arc'hanmael , Rogel Régis , Crand Samuel , Mohammed‐Brahim Tayeb , Le Roy Philippe , Prat Christophe
Published: November 2007

Abstract— A new voltage‐addressed pixel using a multiple drive distribution has been developed to improve, in a simple way, the brightness uniformity of active‐matrix organic light‐emitting‐diode (AMOLED) displays. Moreover, circuits were realized using microcrystalline‐silicon (μc‐Si) films prepared at 600°C using a standard low‐pressure CVD system. The developed p‐channel TFTs exhibit a field‐effect mobility close to 6 cm2/V‐sec. The experimental results show that the proposed spatial distribution of driving TFTs improves the uniformity of current levels, in contrast to the conventional two‐TFT pixel structure. Backplane performances have been compared using circuits based on μc‐Si and furnace‐annealed polysilicon materials. Finally, this technology has been used to make an AMOLED demonstration unit using a top‐emission OLED structure. Thus, by combining both an μc‐Si active‐layer and a current‐averaging driver, an unsophisticated solution is provided to solve the inter‐pixel non‐uniformity issue.
Locally pixel‐compensated backlight dimming on LED‐backlit LCD TV
Authors: Chen Hanfeng , Sung Junho , Ha Taehyeun , Park Yungjun
Published: November 2007

Abstract— The pixel brightness of an LCD panel perceived by a user is the product of the backlight brightness and the panel transmittance. In conventional LCD panels, the backlight brightness is constant and always at peak luminance. This design suffers from light leakage and power waste problems at dark scenes. This paper presents a new LCD system, which uses locally pixel‐compensated backlight dimming (PCBD). The proposed method combines backlight control and pixel processing for reducing light leakage and power consumption while keeping the image at the original brightness. Backlight luminance is dimmed locally in the dark‐image region, and pixel values are compensated synchronously according to the luminance profile of dimmed backlight. By reducing the light leakage, a static contrast of over 20,000:1 has been achieved on a large‐sized LCD panel with the proposed PCBD method. No obvious artifacts have been noticed as well. The power consumption of the panel can also be greatly reduced, depending on various video content. The PCBD method could be widely used for developing state‐of‐the‐art LCD panels with LED backlights.
The Great Society in Education: A Persistent National Consensus?
Authors: Manna Paul
Published: November 2007

This article reviews Gareth Davies, See Government Grow: Education Politics from Johnson to Reagan (Lawrence, Kansas: University of Kansas Press, 2007). The commentary focuses on the author's discussion of federalism and ideological change in the nation's education politics.
Consumer Response to Information and Second-Generation Genetically Modified Food in India
Authors: Anand Alok , Mittelhammer Ron C , McCluskey Jill J
Published: November 2007

This study investigates the Indian market for GM wheat. First, we address the obvious valuation and acceptance questions for Indian consumers. Then we investigate the extent to which the provision of information about GM wheat has any significant effect on consumers' willingness to pay and the degree to which the effect varies based on the information treatment. Finally, we consider whether the type of primary beneficiary of GM wheat production affects valuation. Specifically, we assess the conjecture that consumers' willingness to pay for GM wheat changes according to whether the crop is portrayed as producer-friendly or consumer-friendly.
The Value of Collective Reputation for Environmentally-Friendly Production Methods: The Case of Val di Gresta
Authors: Scarpa Riccardo , Thiene Mara , Marangon Francesco
Published: November 2007

In this paper we investigate consumers' preferences for various environment-friendly production systems for carrots. We use discrete-choice multi-attribute stated-preference data to explore the effect of collective reputations from growers of an Alpine valley known for its environment-friendly production: Val di Gresta 'the valley of organic orchards'. Data analysis of the panel of discrete responses identifies unobserved taste heterogeneity for organic, bio-dynamic and place of origin, while observed heterogeneity for income is addressed by a piece-wise linear function. The implied sample distributions of individual-specific WTP for each of these random attributes are then compared. Results indicate that Integrated Pest Management is preferred to biodynamic as an emerging method. The presence of a premium for Val di Gresta produce is confirmed. The use of an experimental design to identify the relevant second order effects reveals the presence of a reputation effect which can be decomposed into a generic effect from place of origin and a specific one for each EFPMs. Farmers operating in geographically limited marginal areas, such as mountain valleys, may find it useful to invest in collective reputation through high quality standard to achieve higher returns. This strategy may compensate for the dwindling public support to farm income from EU programmes.
Solid Velocity in Shallow Spouted Beds Consisting of Solids of Varying Density
Authors: San Jose Maria J. , Alvarez Sonia , Morales Alberto , Ortiz de Salazar Alvaro , Olazar Martin
Published: November 2007

The vertical component of solid velocity has been measured in shallow spouted beds by means of an optical fibre, for different geometric factors of the contactor (angle and inlet diameter) and under different experimental conditions (height of the stagnant bed, particle diameter and air velocity). The study has been carried out with glass beads and materials of lower density (high- and low-density polyethylene, polypropylene and extruded and expanded polystyrene) in the spout zone of shallow spouted beds. The calculation of velocity along the axis has been carried out by solving a force balance rising along the spout and the core of the fountain.
Experimental and Model Investigations on Gas Mixing Behaviors of Spout-fluid Beds
Authors: Zhong Wenqi , Zhang Mingyao , Jin Baosheng , Xiao Rui
Published: November 2007

Steady-state tracer gas measurements were carried out to study the gas mixing behaviors in a spout-fluid bed with a cross section of 0.3 m x 0.03 m and height of 2 m. Two different tracer gases were simultaneously injected, one was injected into the spouting gas flow and the other was injected into the fluidizing gas flow. Radial tracer gas concentrations at various bed elevations under different flow patterns were measured. The mechanism of gas mixing was discussed based on the racer gas concentrations and the flow patterns recorded by a high-resolution digital CCD camera. It was found that gas mixing in spout-fluid beds was due to both convection and dispersion. A three-region mixing model was developed to describe the gas mixing in the spout-fluid bed. The spout jet region and the boundary region were modeled with a mass transfer model; the annular region was modeled with a dispersion model. Effects of spouting gas and fluidizing gas flow rate on the gas exchange between the spout jet and the annular dense region, and the gas dispersion in the annular dense region were examined with flow patterns. The results showed that increase in spouting gas velocity and fluidizing gas flow rate could both promote the gas mixing in spout-fluid beds. The gas-solid flow pattern transited from internal jet to spouting to spout-fluidizing, and the gases were better mixed. But the gases became poorly mixed when the flow pattern transited from stable flow to instable flow.
Catalytic Production of Carbon Nanotubes in a Swirled Fluid Chemical Vapour Deposition Reactor
Authors: Iyuke Sunny Esayegbemu , Abdulkareem Saka Ambali , Afolabi Samuel Ayo , Piennar Christo H.vZ
Published: November 2007

Catalytic graphitisation of carbon was used to explain the synthesis of carbon nanotubes from acetylene using the catalytic chemical vapour deposition method. This was achieved by comparing the kinetics of synthesis of carbon nanotubes at varying acetylene concentrations and different operating temperature ranging from 850 to 1100 deg.C, using the Langmuir-Hinshelwood mechanism to obtain the model kinetics. Optimum production rate of carbon nanotubes and carbon nanofibres of 8.2mg/s was observed at 1000 deg.C and acetylene concentration of 4725 ppm. 4th order kinetics was also proposed and the data fitted the experiments quite well. Comparison of experimental results with the computed values shows appreciable agreement with correlation coefficients ranging from 0.81-0.99.
Degradation of Odontologic X-Ray Film Developing Wastewaters by Photo-Fenton Process
Authors: Igarashi-Mafra Luciana , Bortoletto Edmilson César , Barros Maria Angelica Simões Dornella , Sorbo Amanda Cristina Alfredo Contrucci , Galliani Naiara Aguiar , Tavares Célia Regina Granhen
Published: November 2007

Effluents from radiographic X-ray film developing processes feature a high contaminant load (COD about 70000 mg/L and total phenols concentration about 16956 mg/L). Photo-Fenton's are potentially useful oxidation processes for destroying toxic organic compounds in water. In these reactions, hydrogen peroxide is combined with ferrous or ferric iron in the presence of light to generate hydroxyl radicals (·OH). The photo-Fenton process was explored as a photochemical treatment to degrade wastewater from radiographic X-ray film developing processes coming from odontologic clinics. A response surface methodology was applied to optimize the photo-Fenton oxidation process conditions using total phenol removal as the target parameter to be optimized, and the reagent concentrations, as related to the initial concentration of organic matter in the effluent, and time and pH as the control factors to be optimized. The best results in terms of maximal total phenol removal and economic process were achieved when wastewater samples were treated at pH 5 in the presence of hydrogen peroxide and iron in the ratios [total phenols]:[H2O2] 1:3 w/w and [Fe2+]:[H2O2] 1:18 w/w and time 1 h.
Estimating the Arm-Wise False Discovery Rate in Array Comparative Genomic Hybridization Experiments
Authors: Gaile Daniel P , Schifano Elizabeth D , Miecznikowski Jeffrey C , Java James J , Conroy Jeffrey M , Nowak Norma J
Published: November 2007

Array Comparative Genomic Hybridization (aCGH) is an array-based technology which provides simultaneous spot assays of relative genetic abundance (RGA) levels at multiple sites across the genome. These spot assays are spatially correlated with respect to genomic location and, as a result, the univariate tests conducted using data generated from these spot assays are also spatially correlated. In the context of multiple hypothesis testing, this spatial correlation complicates the question of how best to define a `discovery' and consequently, how best to estimate the false discovery rate (FDR) corresponding to a given rejection region.One can quantify the number of discoveries as the total number of spots for which the spot-based univariate test statistic falls within a given rejection region. Under this spot-based method, separate but correlated discoveries are identified. We show via a simulation study that the method of Benjamini and Hochberg (1995) can provide a reasonable estimate of the spot-wise FDR, but these results require that the simulated spot assays are categorized as true or false discoveries in a particular way. However, laboratory researchers may actually be interested in estimating a `regional' FDR, rather than a `local' spot-wise FDR. We describe an example of such circumstances, and present a method for estimating the (chromosome) arm-wise False Discovery Rate. In this framework, one can quantify the number of discoveries as the total number of chromosome arms for which at least one spot-based test statistic falls into a given rejection region. Defining the discoveries in this way, both the biological and testing objectives coincide. We provide results from a series of simulations which involved the analysis of preferentially re-sampled spot assay values from a real aCGH dataset.
Testing for Trends in Dose-Response Microarray Experiments: A Comparison of Several Testing Procedures, Multiplicity and Resampling-Based Inference
Authors: Lin Dan , Shkedy Ziv , Yekutieli Dani , Burzykowski Tomasz , Göhlmann Hinrich W.H. , De Bondt An , Perera Tim , Geerts Tamara , Bijnens Luc
Published: November 2007

Dose-response studies are commonly used in experiments in pharmaceutical research in order to investigate the dependence of the response on dose, i.e., a trend of the response level toxicity with respect to dose. In this paper we focus on dose-response experiments within a microarray setting in which several microarrays are available for a sequence of increasing dose levels. A gene is called differentially expressed if there is a monotonic trend (with respect to dose) in the gene expression. We review several testing procedures which can be used in order to test equality among the gene expression means against ordered alternatives with respect to dose, namely Williams' (Williams 1971 and 1972), Marcus' (Marcus 1976), global likelihood ratio test (Bartholomew 1961, Barlow et al. 1972, and Robertson et al. 1988), and M (Hu et al. 2005) statistics. Additionally we introduce a modification to the standard error of the M statistic. We compare the performance of these five test statistics. Moreover, we discuss the issue of one-sided versus two-sided testing procedures. False Discovery Rate (Benjamni and Hochberg 1995, Ge et al. 2003), and resampling-based Familywise Error Rate (Westfall and Young 1993) are used to handle the multiple testing issue. The methods above are applied to a data set with 4 doses (3 arrays per dose) and 16,998 genes. Results on the number of significant genes from each statistic are discussed. A simulation study is conducted to investigate the power of each statistic. A R library IsoGene implementing the methods is available from the first author.
Population Structure and Covariate Analysis Based on Pairwise Microsatellite Allele Matching Frequencies
Authors: Givens Geof H , Ozaksoy Isin
Published: November 2007

We describe a general model for pairwise microsatellite allele matching probabilities. The model can be used for analysis of population substructure, and is particularly focused on relating genetic correlation to measurable covariates. The approach is intended for cases when the existence of subpopulations is uncertain and a priori assignment of samples to hypothesized subpopulations is difficult. Such a situation arises, for example, with western Arctic bowhead whales, where genetic samples are available only from a possibly mixed migratory assemblage. We estimate genetic structure associated with spatial, temporal, or other variables that may confound the detection of population structure. In the bowhead case, the model permits detection of genetic patterns associated with a temporally pulsed multi-population assemblage in the annual migration. Hypothesis tests for population substructure and for covariate effects can be carried out using permutation methods. Simulated and real examples illustrate the effectiveness and reliability of the approach and enable comparisons with other familiar approaches. Analysis of the bowhead data finds no evidence for two temporally pulsed subpopulations using the best available data, although a significant pattern found by other researchers using preliminary data is also confirmed here. Code in the R language is available from www.stat.colostate.edu/~geof/gammmp.html.
The Effect of Variability in Price on Consumer Brand Choice
Authors: Murthi B. P. S. , Haruvy Ernan , Zhang He
Published: November 2007

Grocery store managers change prices on a weekly basis either as part of price promotions or in response to changes on their supply side. Consumers experience this price variability and may respond to it. Even though behavioral literature suggests that price variability affects consumers' decisions, most brand choice models have not focused on the consumers' response to such variability. This study attempts to remedy this omission and examine the effect of price variability on consumer brand choice. We use scanner data to show that price variability affects consumer's price sensitivity. We also find that accounting for the effects of price variability in brand choice models improves the model fit over conventional benchmark models. Our finding has important managerial implications for the strategic use of price variability.
Art as a Scaffolding Teaching Strategy in Baccalaureate Nursing Education
Authors: Hydo Sharon K. , Marcyjanik Diane L. , Zorn CeCelia R , Hooper Nicole M.
Published: November 2007

Although the use of art in nursing education is well highlighted, most of the literature is anecdotal or focuses on development of a reflective nursing practice with clients. In this study, art was used as a scaffold to infuse liberal nursing education by helping baccalaureate nursing students (n = 91) create a personal expression of nursing and move toward greater self-awareness. Scaffolding is a metaphor for supporting learners as they develop higher levels of thinking. Using naturalistic inquiry to analyze students' written responses in a course activity, four themes emerged from the data: art and creativity, teamwork, boundaries and horizons within self, and boundaries and horizons in the profession. Student's individual expressions of art served as the "calling forth" of processes that opened the door to each student's personal expression.
Letter: Why Urgent Emissions Reductions are Needed
Authors: Kallbekken Steffen , Mideksa Torben K
Published: November 2007

Steffen Kallbekken and Torben K. Mideksa explain why economic analysis may demand sharp emissions reductions today rather than the gradual path recommended by Sheila Olmstead and Robert Stavins.
Letter: Observation, Theory-Building, and Theory-Testing
Authors: Tschoegl Adrian E
Published: November 2007

Adrian Tschoegl suggests that proper science is often neither deduction nor induction, but abduction.
Give Freakonomics a Chance
Authors: Ayres Ian
Published: November 2007

An NBA referee has now pleaded guilty, and forensic economists have found signs of bias and cheating in the NBA, college basketball and sumo wresting. Ian Ayres argues that the NBA should release referee data to allow forensic economists to look for statistical evidence of malfeasance, before credibility in results is lost.
Extended Delta Based 15-Phase AC-DC Converter for Variable Frequency Induction Motor Drives
Authors: Garg Vipin , Singh Bhim , Bhuvaneswari G.
Published: November 2007

This paper presents the design and analysis of a multi-phase ac-dc converter system for harmonic reduction at the point of common coupling (PCC) in vector controlled induction motor drives (VCIMD's). The design of the proposed 3-phase to 15-phase autotransformer is presented along with the VCIMD. The proposed 15-phase ac-dc converter is found capable of suppressing up to the 29th harmonic in the supply current, along with the power factor improvement close to unity in the wide operating range of the drive. The effect of load variation on VCIMD is also studied to demonstrate the effectiveness of the proposed ac-dc converter. A set of power quality indices on input ac mains and on dc bus for a VCIMD fed from existing 6-pulse and proposed 15-phase ac-dc converters are also given to compare their performance.
Synchronous Generators Modeling and Control Using the Framework of Individual Channel Analysis and Design: Part 1
Authors: Ugalde Loo Carlos Ernesto , Vanfretti Luigi , Liceaga-Castro Eduardo , Acha Enrique
Published: November 2007

In this paper a comprehensive dynamical assessment of a high order synchronous generator plant is carried out using the Individual Channel Analysis and Design (ICAD) framework a multivariable control engineering tool that allows robustness and system performance evaluations. The great benefits of ICAD are elucidated and contrasted to those provided by the long-time honored block diagram representations. Several models used for the small signal stability analysis of synchronous generators are evaluated under the framework of ICAD. The study, which builds on pioneering work, reveals the great advantages of carrying out control system analysis and design with higher order generator models. Moreover, careful analysis of the ICAD's Multivariable Structure Function (MSF) helps to explain, formally, why some operating conditions of the control system are more critical than others. Furthermore, correct interpretations of MSFs are amenable to robust and stable control system designs. Two kinds of studies are considered in the paper; one assesses operation under various power factor conditions and the other under a varying tie-line reactance. The control system design and stability and structural robustness assessment of the system are presented in the second part of this paper. Moreover, results obtained under the ICAD framework are compared with those arising from conventional controllers.
A Non-Contact Computer Vision Based Analysis of Color in Foods
Authors: Gökmen Vural , Sügüt Idris
Published: November 2007

Since commercial colorimeters measure small area with a fixed geometry, the result of color measurement is usually unrepresentative for heterogeneous materials as in many food items. This paper describes a computer vision based approach for the measurement of color in a user defined polygonal area on the digital image of a food product. The algorithm used for color measurement converts the RGB values of the image captured by a digital camera to monitor L*a*b* values using the standard equations. The RGB responses for a captured image vary from one case to another, so, the direct transformation from RGB to L*a*b is not useful to obtain meaningful information about the color. Here, an artificial neural network (ANN) model was used to convert the monitor L*a*b* values into spectrophotometric L*a*b* values. The ANN model was calibrated by using the IT8 color chart consisting of 288 different colored squares which reflect all possible variations in the color space. The ?E values for the estimated values and the real spectrophotometric values were less than 0.45.
Sorption Isotherms of Granny Smith Apples Hot-Air Dried and Texturized by "Controlled Sudden Decompression to the Vacuum"
Authors: Iguedjtal Tarik , Louka Nicolas , Allaf Karim
Published: November 2007

Moisture sorption isotherms of Granny Smith apples hot-air dried and texturized by Controlled Sudden Decompression (Détente Instantannée Contrôlée DIC®) were determined and compared using a gravimetric method. The DIC has been developed to confer a porous structure to partially dehydrated foods by expanding them and facilitating the drying process at lower water content. The samples were stored in a chamber; the relative humidity is controlled by an atomizing humidifier at 20, 30 and 40°C, and relative humidities ranging from 10% to 90%. The sorption capacity decreased with increasing temperature at a given water activity. The hysteresis effect was not significant for both of the dried and texturized apples. The experimental sorption data were fitted to 8 various isotherm models including two parameter relationships (BET, Halsey, Smith, Henderson, Oswin), three parameter equations (Ferro-Fontan, GAB) and four parameter equations (Peleg). A non-linear least square regression software was used to evaluate the model's constants. The goodness of fit of each isotherm was quantified through the mean relative percentage deviation modulus E. The Ferro-Fontan, Peleg, GAB and Oswin equations were best for characterizing the sorption behaviour of Granny Smith apples for a whole range of temperatures and water activities studied. The surface area corresponding to the monolayer was determined for the texturized apples and compared to the dried samples. The results showed that the treatment by DIC increases the surface area of apples. For understanding the water properties and calculating the energy requirements phenomena, net isosteric heat was evaluated by the applying Clausius-Clapeyron equation.
A Qualitative Investigation of Meta-Imagery Processes and Imagery Direction among Elite Athletes
Authors: MacIntyre Tadhg , Moran Aidan P
Published: November 2007

It has long been known that athletes use mental imagery extensively for a variety of different purposes. Although many of these purposes have been well documented, several gaps remain in our understanding of atheletes' imagery experiences. First, the issue of negative or debilitative imagery among athletes has received little research attention in sports psychology. In addition, until recently, athletes' meta-imagery processes (i.e., their beliefs about the nature and regulation of their own imagery skills) have been neglected. So, the purpose of the present study is to use qualitative methodology to explore meta-imagery processes and imagery direction (i.e., facilitative or debilitative) in elite sports performers. The sample comprised seven participants from motor-sport, rugby, fencing and golf (mean age = 24.43 years; SD = 1.99). Results showed that motivational aspects of imagery were not as relevant to our sample of elite performers as they appear to have been in previous studies using non-elite samples. In addition, the elite performers in our study showed evidence of sophisticated meta-imagery control skills  being able, for example, to restructure negative imagery so that it facilitates future performance. Finally, our elite sample's experience of imagery direction seems to be more complex than had previously been believed. For example, some athletes reported deliberately imagining errors in order to prepare for "worst-case" scenarios in competition (hence using such imagery to facilitate their performance). Overall, we propose that existing imagery use taxonomies that need to be revised to take into account the flexibility with which elite athletes actually employ imagery.
Multirate Constrained Predictive Control: Algorithm and Experimental Results
Authors: Hu Qiuping , Rohani Sohrab
Published: November 2007

Control of multirate systems is a challenging problem due to several reasons such as increased complexity in the design with tighter performance specifications. In this work, an algorithm for multirate constrained predictive control (MCPC) is presented. The multirate predictive control system includes a multirate state estimator, which provides inter-sample estimates of state variables of the process from infrequent and slow measurements. Constraints are addressed rigorously in this framework. The proposed design method is verified via simulation as well as experimentation. The results of the multirate predictive control for temperature control of a stirred tank system are shown and compared with those of a proportional integral (PI) control system.
Extended Modeling Framework for Heat and Power Integration in Batch and Semi-continuous Processes
Authors: Puigjaner Luis
Published: November 2007

Flexible manufacturing and processing, which are becoming crucial for companies that wish to remain competitive in today's changing market environment, require the detailed modeling of process operations, as well as the incorporation of utility consumption modeling and energy integration strategies. In this paper, a comprehensive modeling environment for heat and power integration in batch and semi-continuous processes is presented. Moreover, a general procedure concerning utility generation and utility system design optimization is described. This framework has been tested and evaluated as part of an industrial case study. The results obtained indicate that the general design methodology developed is effective for process integration of time-dependent processes with combined heat and power.
Understanding Participation in Social Programs: Why Don't Households Pick up the Lifeline?
Authors: Burton Mark , Macher Jeffrey , Mayo John W
Published: November 2007

In this study, we draw upon data from the low-income Lifeline Assistance Program (Lifeline) for telephone service to examine the participation of eligible households in social programs designed to alleviate financial hardship. Utilizing panel data on participation levels in 1997 and 2003 and the associated variation in state-level policies, we are able to identify program characteristics that significantly affect participation rates. In particular, we find that participation rates are significantly negatively influenced by limitations that some states place on the ability of Lifeline subscribers to utilize optional calling features such as three-way calling or call forwarding. We also find that program participation is positively influenced by the longevity of the individual state's Lifeline program. While no direct test of state-level advertising is feasible, this result is suggestive of an inter-temporal pattern of information dissemination that grows with program longevity. Because eligibility for the Lifeline service is conditional upon participation in other low-income public programs, we also find that: (1) the larger the number of "portals" (i.e., low income public programs that states identify as creating Lifeline eligibility), the higher is participation; and (2) higher financial benefits of these portal programs attract greater participation in Lifeline programs. These results suggest important linkages that may be exploited through coordination of low-income assistance programs. Finally, we test for, and find that variations in Lifeline benefits significantly influence participation rates.
Visa Screening and Collateral Import of Terrorism
Authors: Das Satya P , Lahiri Sajal
Published: November 2007

A static game-theoretic model is developed to examine the post-9/11 interaction between the higher-education sector and the visa authority. We analyze the determination of the sponsorship of foreign scholars by the former and of visa scrutiny level by the latter, when some of the applicants, unknown to either party, are potential terrorists. When some genuine scholars are denied visa mistakenly, the intensity of visa screening is higher than its efficient level, but the number of students sponsored by the universities may or may not be higher. When delays associated with visa scrutiny cause some genuine scholars to be unable to enter, both the number of foreign scholars sponsored and the intensity of visa scrutiny are higher than their efficient levels. Under the same case, as the proportion of bad applicants (who are potential terrorists) for visas increases, the number of foreign scholars sponsored and the intensity of visa scrutiny increases, while there is a decline in the proportion of visa applicants granted visas. The basic analysis is extended to the case where the pool of applicants is endogenous.
Gender Specialization of Skill Acquisition
Authors: Ishida Junichiro , Nosaka Hiromi
Published: November 2007

This paper presents a model that can account for the gender specialization of skill acquisition in the presence of competitive matching. In particular we show that when the comparative advantage in nonmarket domestic activities belongs to women, an incentive arises for them to intentionally degrade the market value of acquired skills in order to secure gains from the marriage market. We then show that this incentive can be excessively strong and gives rise to the emergence of an inefficient asymmetric equilibrium where women concentrate excessively on acquiring skills that do not lead to higher wages in the labor market. The analysis reveals why policy interventions such as affirmative action programs or equal employment opportunity laws that directly subsidize the acquisition of skills for women would not be effective in closing the gender earnings gap in the long run, and instead suggests that extensive family policies are generally more effective in this regard.
Pareto Optima and Competitive Equilibria with Moral Hazard and Financial Markets
Authors: Panaccione Luca
Published: November 2007

In this paper, we study a two-period pure exchange economy with idiosyncratic uncertainty, moral hazard and multiple consumption goods. We consider two different market structures: contingent commodity markets on the one hand, and financial plus spot commodity markets on the other hand. We propose a competitive equilibrium concept for each market structure. We first verify that it is possible to decentralize constrained efficient allocations as equilibria with contingent markets. Subsequently, we characterize the conditions which prevent constrained efficient allocations from being decentralized as equilibria with financial markets.
An "African" Gospel: American Evangelical Radio in West Africa, 1954-1970
Authors: Stoneman Timothy H.B.
Published: November 2007

During the second half of the twentieth century, Christianity underwent an epochal transformation from a predominantly Western religion to a world religion largely defined by non-Western adherents in Africa, Asia, and Latin America. Broadcast media, spearheaded by American evangelical missionaries, played an important role in the globalization of Christianity. After WWII, conservative Protestant missionaries from the United States established a ``far-flung global network" of radio stations around the world with the avowed purpose of proselytizing the entire globe. In Liberia, American missionaries organized Station ELWA, the first evangelical station in Africa. The medium of radio proved well suited to the ``universal" mission of American evangelicals, particularly after the expansion of worldwide ownership in transistor radios during the 1960s. Yet the success of missionary radio stations such as ELWA rested on an extensive process of translation into local customs and practices. Between 1954 and 1970, ELWA officials and workers constructed transmission platforms, political relations, language services, receiver distribution campaigns, and community networks. These constructs functioned as the crucial grids through which the ``universal" meaning of evangelicalism was produced at the grass-roots level. As the history of ELWA in Liberia makes clear, American evangelical broadcasters acquired converts only by adapting their gospel message to fit particular churches, cultures, and contexts across the globe. Localizing missionary radio required the appropriation of indigenous cultural capital, the transposition of national partners, and the active agency of audiences on the ground.
The Contradictions of Techno-Nationalism and Techno-Globalism: A Historical Perspective
Authors: Edgerton David E.H.
Published: November 2007

Techno-nationalism and techno-globalism are descriptive and prescriptive categories for understanding the impact of technology on society and vice versa. They reflect the underlying assumptions made by analysts of the place of technology in the world, and denote ideologies, rather than technological policies or realities. They also help us to realize that standard accounts of the nation and globalization are not as securely based as they appear. Indeed, nations and states are important in ways techno-nationalism does not capture, and the international and global dimension is crucial in ways which that techno-globalism overlooks. Yet an analysis of both terms yields building blocks to a more sophisticated appreciation of the linkages between the nation, technological innovation and globalization.
Food for the Masses
Authors: Thompson Phyllis
Published: November 2007

Phyllis Thompson reviews Kenneth Kiple's A Movable Feast: Ten Millennia of Food Globalization.
ESR studies of antioxidative activity of different elecampane (Inula helenium L) extracts
Authors: Canadanovic-Brunet Jasna , Djilas Sonja , Cemkovic Gordana , Tumbas Vesna , Malesevic Zoranka
Published: November 2007

The influence of petroleum ether, ethyl acetate and water extracts of elecampane (lnula helenium L) on the transformation of the stable 1,1-diphenyl-2-pycrylhydrazil (DPPH) radicals has been investigated by ESR spectroscopy. Using the phytochemist "screening" test a qualitative analysis of extracts has been made. On the basis of the obtained results it can be concluded that the investigated elecampane extracts have the antioxidative activity due to the hydrogen donor ability of the constituent biomolecules such as tannins, terpenes, polyphenols, etc. The following order of antioxidative activity has been established: ethyl acetate > petroleum ether > water extracts. Also, the investigation showed that the antioxidative activity increased with increasing concentration of all the extracts.
Optimization of petroleum acid isolation from lower oil fractions of Vojvodina "Velebit" oil
Authors: Cirin-Novta Vera , Kevresan Slavko , Kuhajda Ksenija , Kandrac Julijan , Radic Ljubica , Rodic Petar
Published: November 2007

Petroleum acids can be obtained from oil and oil derivatives by alkaline extraction. The aim of this work was to optimize the process of alkaline extraction of petroleum acids from light commercial oil fractions of Vojvodina "Velebit" oil by changing the contact time of oil fraction with strong alkali and by changing the reaction temperature. Optimal conditions for isolation of petroleum acids have been determined to be 9 hours of contact time and reaction temperature of 90?C. Under these conditions the obtained petroleum acids yield was 88.38%. Identification of isolated acids was performed by GC-MS analysis.
Preparation and characterization of aluminum stearate
Authors: Loncar Eva , Lomic Gizela , Malbasa Radomir , Kolarov Ljiljana
Published: November 2007

Preparation of aluminum stearate by the precipitation method was examined under various conditions of stearic acid saponification with sodium hydroxide. It was proved that the most favorable ratio of acid/alkali was 1:1.5 and that the obtained soap was very similar to the commercial product. Endothermic effects determined by differential scanning calorimetry and also the other parameters showed that the soaps consisted mono-, di-, tristearates and non-reacted substances, where distearate was the dominant form.
Synthesis and physico-chemical characterization of zinc(II), nickel(II) and cobalt(II) complexes with 2-phenyl-2-imidazoline
Authors: Podunavac-Kuzmanovic Sanja , Vojinovic Ljiljana
Published: November 2007

Chlorides and nitrates of zinc(II), nickel(II) and cobalt(II) react with 2-phenyl-2-imidazoline to give complexes of the type [ML2X2]?nH2O (M=Zn, Ni or Co; L=2-phenyl-2-imidazoline; X=Cl or NO3; n=0, 1 or 2). The complexes were synthesized and characterized by elemental analysis of the metal molar conductivity, magnetic susceptibility measurements and IR spectra. The molar conductances of the zinc(II) complexes in DMF solutions indicate that the complexes behave as non-electrolytes. The values of magnetic conductivity in the case of nickel(II) complexes indicate that one of the coordinated anions (chloride or nitrate) has been replaced by DMF molecule. The molar conductivity values of cobalt(II) complexes indicate the partial substitution of coordinated anions with solvent molecules. The room temperature effective magnetic moments and IR data of the complexes suggest that all Zn(II), Ni(II) and Co(II) complexes have a tetrahedral configuration, which is realized by participation of the pyridine nitrogen of two organic ligand molecules, and two chloride or nitrate anions typical for these classes of organic ligands.
Production of highly porous glass-ceramics from metallurgical slag, fly ash and waste glass
Authors: Mangutova Bianka , Fidancevska Emilija , Milosevski Milosav , Bossert Joerg
Published: November 2007

Glass-ceramics composites were produced based on fly-ash obtained from coal power stations, metallurgical slag from ferronickel industry and waste glass from TV monitors, windows and flasks. Using 50% waste flask glass in combination with fly ash and 20% waste glass from TV screens in combination with slag, E-modulus and bending strength values of the designed systems are increased (system based on fly ash: E-modulus from 6 to 29 GPa, and bending strength from 9 to 75 MPa). The polyurethane foam was used as a pore creator which gave the material porosity of 70(5% (fly ash-glass composite) and a porosity of 65( 5% (slag-glass composite). E-modulus values of the designed porous systems were 3.5(1.2 GPa and 8.1(3 GPa, while the bending strength values were 6.0(2 MPa and 13.2(3.5 MPa, respectively. These materials could be used for the production of tiles, wall bricks, as well as for the construction of air diffusers for waste water aeration.
Immobilized lipases as practical catalysts
Authors: Knezevic Zorica , Siler-Marinkovic Slavica , Mojovic Ljiljana
Published: November 2007

Attractive features of lipase systems include versatility, substrate selectivity, regioselectivity, enantioselectivity and catalysis at ambient temperatures and pressures. To fully exploit the technical and economical advantages of lipases, it is recommended to use them in an immobilized form to reduce the cost and the poor stability of the free lipase. This paper summarizes various methods of lipases immobilization including covalent attachment to or adsorption on solid supports, encapsulation and entrapment within the membrane and in polymeric matrices. The effects of immobilization conditions on lipase properties and stability of biocatalysts are considered. Applications of immobilized lipases in the feasible reaction system as well as probable future trends in lipase catalyzed process are discussed.
Antioxidant properties of ethanolic extract of sugar beet pulp
Authors: Sakac Marijana , Pericin Draginja , Mandic Anamarija , Kormanjos Sandor
Published: November 2007

The ethanolic extract of sugar beet pulp at 100% exibited good antioxidant activity of 69.74%. It showed an excellent scavenging activity on 1,1-diphenyl-2-picrylhydrazyl radicals (84.94%) and was a mild chelator for ferrous and cupric ions. On the basis of some identified phenolic acids in ethanolic extract from sugar beet pulp it is concluded that predominant acids (ferulic, gentisic and p-coumaric acid), which have been previously evidented as relatively potent antioxidants, contribute to the antioxidant properties of the investigated extract. Antioxidative nature of ethanolic extract from sugar beet pulp, that is sugar beet pulp itself, indicate that it could be used as antioxidative component for decreasing oxidative changes in foods.
Sunflower meal protein as a feed for broilers
Authors: Levic Jovanka , Sredanovic Slavica , Djuragic Olivera
Published: November 2007

The paper provides an overview of the nutritional aspects associated with the utilization of sunflower meal in broiler diets. To gain the maximum benefit from this feed ingredient, some of the characteristics of sunflower meal must be considered. In broiler diets, it is recommended that only high-quality decellulosed sunflower meal be used. Our own results and a broad variety of published reports have thus been consulted. Experiments with high protein sunflower meal in broiler diets have shown that sunflower meal can successfully replace soybean meal, provided that diets are supplemented with adequate amounts of lysine and energy. Consequently, the inclusion of sunflower meal in broiler diets may vary depending on the fiber content of the meal, the lysine and/or energy supplementation of the diet.
Varietal and environmental influence on the yield and the end-use quality of sugar beet
Authors: Radivojevic Stevan , Dosenovic Irena
Published: November 2007

Environmental factor (location) influenced sugar beet root yield, which was higher by 20.6% on Belgrade location than on Pancevo location. However, when compared the genotype effect, smaller environmental influence was found for root yield, which was not expected. The investigated factors (variety and location) equally contributed to the variation in root sugar content. Significantly higher varietal influence was observed for granulated sugar yield, which was also unexpected. .
Absorption of laser irradiation in a porous powder layer
Authors: McVey R. W. , Melnychuk R. M. , Todd J. A. , Martukanitz R. P.
Published: November 2007

An analytical relationship was derived to describe the amount of energy absorbed within preplaced powder during the laser deposition process. The relationship, which reflects an exponential decay of Beer–Lambert, may be used to define internal absorption due to scattering within the powder layer regardless of the beam shape and energy distribution if the attenuation coefficient and bulk absorption are known. Experiments were conducted to estimate the attenuation coefficients for pure iron and pure copper powders, representing three powder size distributions, during CO2 and Nd:yttrium-aluminum-garnet (YAG) laser irradiation. Qualitative observations and trends of the experimental data indicated that greater beam penetration, accompanied by a decrease in the estimated attenuation coefficients, was associated with the larger powder particles, the lower wavelength of the Nd:YAG laser, and the copper powder. Attenuation coefficients were determined for the original powder size distributions and a larger size distribution obtained by sieving. The estimated attenuation coefficients representing the original powder size distributions were found experimentally to be 0.0144 μm−1 for the iron powder and 0.0113 μm−1 for the copper powder. These values compared to those of the materials in the solid state indicate that the attenuation coefficients of the powders are four orders of magnitude less and represent significant penetration of irradiation into the powder layer.
Novel technique for laser lap welding of zinc coated sheet steels
Authors: Li X. , Lawson S. , Zhou Y. , Goodwin F.
Published: November 2007

When zinc coated steels are laser welded, zinc adjacent to the weld bead is vaporized and will cause serious weld pool disruption in lap welding unless special measures are applied such as provision of a joint gap for vapor venting. A novel alternative technique has been developed to stabilize laser lap welding: this involves addition of a small amount of aluminum to the faying surface region, so that a liquid Al–Zn alloy of high boiling point is formed, thus lowering the Zn vapor pressure. Lap welds have been made with good process stability using Nd: yttrium–aluminum–garnet and direct diode lasers, and with added Al in the form of inserted foil or previously applied cold sprayed coatings. The development is described in U.S. Patent Application No. 11/226,834. Process optimization is currently under way to define optimum aluminum addition rates that will reliably suppress defects while minimizing Al uptake into the steel weld pool.