bluuebunny/crossref_metadata_2025 huggingface dataset:
LCD backlights, light sources, and flat fluorescent lamps
Authors: Park J. L. , Lim Sungkyoo
Published: November 2007

Abstract— Backlights are indispensable for the operation of LCDs. Light sources or lamps are the core components of backlights. There are many types of light sources for backlights such as cold cathode fluorescent lamps (CCFLs), external electrode fluorescent lamps (EEFLs), hot‐cathode fluorescent lamps (HCFLs), flat fluorescent lamps (FFLs), and light‐emitting diodes (LEDs). Recently, FFLs are becoming one the most interesting light sources for LCD‐TV backlights. Channel profiles and the structure of FFLs in more detail are discussed in this paper. The channel profile of FFLs with maximum brightness uniformity was designed, fabricated, and characterized. The FFL backlight demonstrated 10,500 nits and the total power consumption was 110 W at room temperature.
Targeting Corporate Political Strategy: Theory and Evidence from the U.S. Accounting Industry
Authors: Vanden Bergh Richard G. , Holburn Guy L.F.
Published: November 2007

By analyzing the interaction between a business firm and multiple government institutions (including a regulatory agency, an executive and a bicameral legislature), we develop predictions about how firms target their political strategies at different branches of government when seeking more favorable public policies. The core of our argument is that firms will target their resources at the institution that is ‘pivotal’ in the policy-making process. We develop a simple framework, drawing on the political science literature, which identifies pivotal institutions in different types of political environments. We find empirical support for our thesis in an analysis of how U.S. accounting firms shifted their political campaign contributions between the House and Senate in response to the threat of new regulations governing auditor independence during the 1990s.
Rudy and Mike: Will Either of the Mayors Who Saved New York Get the Chance to Save America?
Authors: Kraus Jeffrey
Published: November 2007

The author discusses Rudolph Giuliani and Michael Bloomberg, the two most recent Mayors of New York City, and their prospects for the Presidency. While the New York mayoralty has historically been a ``political dead end," Giuliani is a front-runner for the Republican nomination and Bloomberg is being discussed as a potential independent candidate. The author briefly examines their leadership styles and offers some ideas about how they might deal with aspects of the Presidency. Finally, the author notes the possibility that two other ``New Yorkers" also are serious candidates: Senator Hillary Clinton, who was elected to the Senate while still First Lady, and Fred Dalton Thompson, the unannounced candidate for the Republican nomination. Thompson, who served in the U.S. Senate for eight years (1995-2003), and before that had come to national prominence as the Minority Counsel during the Senate's Watergate Hearings (1973), is known to many voters as ``Arthur Branch," the fictional Manhattan District Attorney, a character that he has played for the last five seasons (2002-2007) on the NBC television program, ``Law and Order."
The Grand Coalition and a Changing Political Order: Shifting Alliances and a New Era in German Politics
Authors: Clemens Clay M
Published: November 2007

Since its 2005 federal election, Germany has been governed by the country's two historically strongest political rivals, the center-right Christian Democratic Union/Christian Social Union (CDU/CSU) and center-left Social Democratic Party (SPD). Despite initial hope in some quarters that this broad-based Grand Coalition under Chancellor Angela Merkel could overcome partisan gridlock and enact major policy changes, seeking to work together has only fed frictions within as well between both partners. A resulting stalemate has reinforced the more skeptical view that this government was in fact destined to remain at most a transitional one. It only came about in the first place due to an increasing fractionalization of the party system, as the declining core support for CDU/CSU and SPD boosted several smaller contenders, yet also denied either of two more familiar federal alliances--center-right (CDU/CSU-Liberal) or center-left (SPD-Green)--a clear parliamentary majority. There is thus widespread and mounting speculation that Germany's next national election will produce a wholly new governing constellation, one based on multiple parties, perhaps one crossing all traditional bloc divisions, or possibly one drawn entirely from the left; Germany might conceivably even enter a phase of minority government. While to be sure all such scenarios remain hypothetical, the Federal Republic does seem poised on the edge of a new political era.
Catalytic Wet Air Oxidation of Aqueous Organic Mixtures
Authors: Creanga Manole Carmen , Ayral Catherine , Julcour Lebigue Carine , Wilhelm Anne-Marie , Delmas Henri
Published: November 2007

Catalytic Wet Air Oxidation (CWAO) has been investigated for the treatment of water contaminated by 4-hydroxybenzoic acid (4HBA) and equimolar mixture of phenol-4HBA. Both batch measurements for kinetics determination and continuous fixed bed operation have been performed on the same Activated Carbon (AC). After a fast initial deactivation AC was proved stable and efficient at moderate temperature and oxygen pressure, like for phenol degradation.The kinetic study in the case of highly adsorbing material as AC may require complex approach to account for the variation of adsorbed reactants during batch oxidation. Adsorption isotherms at reaction temperature and with aged AC have been obtained according to Langmuir equation and used in 4HBA mass balance to derive more significant kinetic parameters. At high catalyst loading and relatively low pollutant concentration, the variation of 4HBA during the batch may be even higher on the solid than in the aqueous phase.
Simulation, Case Studies and Optimization of a Biodiesel Process with a Solid Acid Catalyst
Authors: West Alex H , Posarac Dusko , Ellis Naoko
Published: November 2007

A commercial process simulator was used to develop a detailed simulation of a biodiesel production process, and carry out case studies and optimization. The simulated process produced biodiesel from a feedstock containing 5 wt.% free fatty acids in a fixed-bed reactor with sulfated-zirconia as an acidic catalyst. Sized unit operation blocks, material and energy flows were used to conduct an economic assessment of the process. Total capital investment, total manufacturing cost, after tax rate-of-return and production cost ($/kg) were all determined for the process. The process was then optimized by maximizing the after tax rate-of-return (ATROR). Based on our previous work, the most economical process for transesterification of waste vegetable oil at the scale of 8000 metric tones/yr of biodiesel production among the four processes examined was based on a solid acid catalyst reaction. Our results showed that the process is economically feasible, even without government subsidy, while at the same time, the produced biodiesel met the required ASTM standard for purity.
Kinetic Modelling of Toxic Compounds Generated during Phenol Elimination in Wastewaters
Authors: Villota Natalia , Mijangos Federico , Varona Fernando , Andrés Javier
Published: November 2007

This work focuses on the application of Advanced Oxidation Processes (AOPs) to purify phenolic effluents, which when combined with innovation and effectiveness contribute towards the preservation of natural resources and environmental quality. Phenols are typical pollutants found in wastewaters from different industries such as petrochemical, pharmaceutical, resin manufacturing, olive-oil, pesticides, dyeing production or cosmetic industry. Nevertheless due to their toxicity and harmfulness, they cannot be poured to water systems. Phenol has been chosen as a model compound in this study because it is usually a component of industrial wastewaters. Furthermore phenol-like compounds are generated by intermediate compounds in the oxidation pathway of higher molecular weight aromatic hydrocarbons.Phenol can be effectively removed but this does not imply that the all toxicity levels of the effluent have been diminished, since the oxidation pathway passes through more toxic products. Before each AOP application, the reaction intermediates must be identified in order to determine the influence they have on operating conditions, and subsequently establish the criteria for the complete destruction of toxic compounds. These studies will assist in the cost-effective operation of industrial setups, and also in the design of integrated processes for wastewater treatment.The main objectives of this work are, first to identify and measure toxic intermediates and, second, to develop a kinetic model for phenol degradation based on a mechanism in series. Chemical pathways in the phenol oxidation consider its hydroxylation to catechol, hydroquinone and resorcinol. These dihydroxylated rings are later oxidised to quinone-like compounds. These quinone-like compounds break into short-chain acids, like acetic, formic and oxalic acids. In order to propose a reaction pathway several runs were carried out at room temperature controlling the operational pH throughout the reaction. Experiments were carried out under different operating conditions, and the decay curves of phenol and aromatic intermediates were monitored, using doses of oxidant and catalyst until R=40 mol oxidant/mol phenol and [Fe(II)]=20 mg/L. Kinetic parameters were rightly fitted to the kinetic model, predicting successfully the reaction rates of each toxic compounds.
Integration of Thermal Treatment and Catalytic Transformation for Upgrading Biomass Pyrolysis Oil
Authors: Valle Beatriz , Gayubo Ana Guadalupe , Atutxa Alaitz , Alonso Ainhoa , Bilbao Javier
Published: November 2007

The upgrading of bio-oil by catalytic transformation upon acidic catalysts is aimed at adapting its composition to that of conventional fuel, or at obtaining petrochemical raw materials, such as olefins and aromatics. A further alternative of growing interest for bio-oil upgrading is catalytic reforming for obtaining H2. The viability of any of these alternatives requires minimizing both the plugging problems that arise in the reactor when the bio-oil is fed and the rapid deactivation of the catalyst, which are associated with the thermal degradation of the lignocellulosic components. In this paper, the catalytic transformation of bio-oil (obtained by fast pyrolysis of vegetable biomass) in a fluidized bed reactor upon a Ni-HZSM-5 zeolite catalyst has been studied, and special attention has been paid to the design of the feed preheating zone. Operation in a single-unit (U-shaped steel tube) for the thermal treatment of the bio-oil (in the downward zone of the U-tube) and its catalytic transformation (in a fluidized bed located in the upward zone of the U-tube) has been compared with operation in a two-unit system, where both steps are carried out in separate units connected through a thermostated line (U-shaped tube for thermal treatment, followed by a fluidized bed reactor for catalytic transformation). It has been proven that a separate step of thermal treatment prior to the catalytic transformation notably improves the global process of bio-oil upgrading. Firstly, it contributes to minimizing coke deposition on the acidic catalyst, mainly the deposition of "thermal" coke (which is associated with the thermal degradation of the bio-oil components at high temperatures), leading to an important attenuation of catalyst deactivation. Secondly, the bio-oil components degraded in the thermal treatment can subsequently be subjected to another upgrading treatment (by steam activation or pyrolysis) in order to obtain a high quality char, which involves upgrading the entire bio-oil.
Radiation Field in an Annular Photocatalytic Reactor by the P1 Approximation
Authors: Cuevas Sergio A , Arancibia-Bulnes Camilo A , Serrano Benito
Published: November 2007

Heterogeneous photocatalysis with titanium dioxide TiO2 is an advanced oxidation processes that uses ultraviolet radiation to carry out reactions leading to the degradation of polluting agents in water. For the development and scaling up of efficient photocatalytic processes it is important to model the transport of radiation in the reactor volume, because it affects the photo reaction. In the present work we have used the P1 approximation of radiative transfer theory to evaluate radiation distributions inside a specific annular photocatalytic reactor known as Photo CRECWater II. The reactor consists of two concentric tubes with a TiO2/water suspension flowing axially in the annular space between them, and a lamp at the center of the inner tube. The theoretical results are compared with experimental data from measurements of radiation transmission through several observation windows in the external reactor wall. In general the model describes the observed experimental results well. Due to the nature of the employed approximation a good quantitative agreement is possible only for suspensions with a large optical depth. For small optical depths the agreement is adequate only for the central portion of the reactor length.
On the Operational Characteristics of the Benjamini and Hochberg False Discovery Rate Procedure
Authors: Green Gerwyn H , Diggle Peter J.
Published: November 2007

Multiple testing procedures are commonly used in gene expression studies for the detection of differential expression, where typically thousands of genes are measured over at least two experimental conditions. Given the need for powerful testing procedures, and the attendant danger of false positives in multiple testing, the False Discovery Rate (FDR) controlling procedure of Benjamini and Hochberg (1995) has become a popular tool. When simultaneously testing hypotheses, suppose that R rejections are made, of which Fp are false positives. The Benjamini and Hochberg procedure ensures that the expectation of Fp/R is bounded above by some pre-specified proportion. In practice, the procedure is applied to a single experiment. In this paper we investigate the across-experiment variability of the proportion Fp/R as a function of three experimental parameters. The operational characteristics of the procedure when applied to dependent hypotheses are also considered.
Taking the Patient to the Classroom: Applying Theoretical Frameworks to Simulation in Nursing Education
Authors: Waldner Magda H , Olson Joanne K
Published: November 2007

Upon completion of their education, nursing students are expected to practice safely and competently. Societal changes and revisions to nursing education have altered the way nursing students learn to competently care for patients. Increasingly, simulation experiences are used to assist students to integrate theoretical knowledge into practice. Reasons for and the variety of simulation activities used in nursing education in light of learning theory are discussed. By combining Benner's nursing skill acquisition theory with Kolb's experiential learning theory, theoretical underpinnings for examining the use of simulations in the context of nursing education are provided.
Do Voluntary Carbon Offsets Work?
Authors: Gans Joshua S
Published: November 2007

Voluntary purchases of offsets for carbon emissions have been criticized as potentially increasing emissions. However, Joshua S. Gans argues that even if offsets do increase the consumption of carbon intensive goods, net emissions will always fall because these goods will become less carbon intensive.
Bridge Building and Integrative Treatment of People with Multiple Sclerosis. Research-based Evaluation of a Team-building Process
Authors: Launsø Laila , Haahr Niels
Published: November 2007

Background: The Danish Multiple Sclerosis Society has initiated a research project dealing with bridge building and integrative treatment. Little attention has been paid to research on the experience of conventional and alternative practitioners with bridge building and integrative treatment through teamwork. Objective: The objective of this article is to describe essential features of the preparatory phase of the research project focusing on the process of initiating and developing a team of conventional and alternative practitioners before treating people with Multiple Sclerosis at a specialized MS hospital in Denmark. The team consists of five conventional and five alternative practitioners. Materials and Methods: The preparatory phase took place from August 2004 to May 2005. In-depth, semi-structured interviews were conducted with the ten team practitioners. Each practitioner was interviewed before and eight months after joining the team, and after participating in four practitioner-researcher seminars. Written materials and participatory observations of practitioner-researcher seminars have been used in addition. Results: The team-building process involved motivation, emotions, challenges, professional and personal competences, and the development of a professional team identity. The practitioners assessed the preparatory phase based on researcher-practitioner seminars as an essential basis for moving on to provide treatments to people with MS.
Preventive Effects of an Extract of Erythrina Lysistemon (Fabaceae) on Some Menopausal Problems: Studies on the Rat
Authors: Njamen Dieudonné , Magne Ndé Chantal Béatrice , Tanee Fomum Zacharias , Mbanya Jean Claude
Published: November 2007

Objective - Our purpose was to determine the advantage of early treatment (before ovariectomy) on a preventive basis of an ethyl acetate extract of Erythrina lysistemon (EL) on menopausal signs, an extract which has previously shown estrogenic activity by acting through the oestrogen receptors.Methods - Female Wistar rats aged 1-1.5 month were randomised in groups and treated respectively from 28 days before ovariectomy to 84 days after. The fasting lipids levels, glucose tolerance, bone and uterine weight, uterine and vaginal epithelial height were determined at days 0, 28, 56 and 84; whereas body weight was determined every forth night.Results - Oral administration of 200mg/kg/d of EL significantly increased HDL-cholesterol and LDL-cholesterol levels on days 0 and 28 and decreased them at days 56 (70%) and 84 (48.27%) compared to untreated ovariectomized rats. It also significantly increased bone weight. Further, EL at day-56 controlled glucose intolerance; but it failed to do so at day-84 and significantly increased blood glucose level. At day 0, EL significantly decreased uterine weight of animals as well as E1. In contrast 28 days after ovariectomy, EL significantly increased uterine weight (36.43%), uterine (19.71%) and vaginal (31.76%) epithelial height with a more advance vaginal cornification compared to controls.Conclusion - These results suggest that oral administration of 200mg/kg/d of EL 28 days before ovariectomy prevented bone loss. EL had a transient effect on glucose intolerance. However EL significantly increased HDL-cholesterol and decreased TG levels.
Dynamic Economic Emission Dispatch Using Evolutionary Programming and Fuzzy Satisfying Method
Authors: Basu Mousumi
Published: November 2007

Dynamic economic emission dispatch is an extension of the conventional economic emission dispatch problem that takes into consideration the ramp rate limits of the generators. Evolutionary programming based fuzzy satisfying method has been proposed to determine the optimal noninferior generation schedule. This paper treats economy and emission as competing objectives for optimal dispatch, which requires some form of conflict resolution to arrive at a solution. The multi-objective problem is configured as a minimax problem under the assumption that the decision-maker has fuzzy goals for each of the objective functions. The present algorithm employs evolutionary programming technique in solving this problem. The solution methodology can offer a global or near-global noninferior solution for the decision-maker. Numerical results of a sample test system have been presented to demonstrate the performance and applicability of the proposed method. Results obtained from the proposed method are compared to those obtained by fuzzy satisfying method based on simulated annealing technique.
Dispatch Optimisation of Renewable Energy Generation Participating in a Liberalised Electricity Market
Authors: Bhandari Narad Muni , Burt Graeme , Dahal Keshav Prasad , Galloway Stuart , McDonald Jim
Published: November 2007

This paper focuses on dispatching of mixed generation portfolio of renewable energy (RE) and non-RE (firm) units. A genetic algorithm (GA) based rolling window approach is developed for solving economic dispatch (ED) problem. Profit maximisation ED problem is formulated and solved which also considers New Electricity Trading Arrangements for England and Wales (NETA) market features. In this problem, a penalty approach is used in order to consider intermittency problem of RE generation output. A single GA technique is also applied for solving the formulated problem. Of these, GA based rolling window approach achieved promising results for a Generator Company, which holds both renewable and fossil fuel units and participates in the short-term market trading. It is also shown that a Generator Company can get more profit by using the possibility of increase in generation output of RE sources from their forecast positions by combining both RE and non-RE units and participating in a NETA-like market trading. This approach allows to some extent the management of uncertainty problem of RE generation output, which also accounts risk associated with power non-delivery.
Expanding an Industrial Load Model for Short-Term Voltage Stability Analysis
Authors: Onoda Pessanha Jose Eduardo , daSilva Fabio M , Saavedra Osvaldo , Buzar Julio Cesar R
Published: November 2007

The present work proposes an extended model representing part of a huge aluminum industry load for short-term voltage stability investigations in time domain. The efforts were concentrated in the expansion of the industrial power distribution system model including explicit representation of the main transformers, capacitors, feeders and induction motors. The extended model is validated through a comparison between computer simulation results and the industry/power system utility recordings. A real sequence of events which took place in the Brazilian North Power System in the year of 2002 causing a complete industry breakdown (loss of bulk supply) was considered here for this purpose.
Robust Approach for Identification of Bad Data in State Estimation Using SLP Technique
Authors: Dhadbanjan Thukaram , Khincha H. P. , Phaniram M. S.S.
Published: November 2007

This paper proposes a new approach for solving the state estimation problem. The approach is aimed at producing a robust estimator that rejects bad data, even if they are associated with leverage-point measurements. This is achieved by solving a sequence of Linear Programming (LP) problems. Optimization is carried via a new algorithm which is a combination of ``upper bound optimization technique" and ``an improved algorithm for discrete linear approximation". In this formulation of the LP problem, in addition to the constraints corresponding to the measurement set, constraints corresponding to bounds of state variables are also involved, which enables the LP problem more efficient in rejecting bad data, even if they are associated with leverage-point measurements. Results of the proposed estimator on IEEE 39-bus system and a 24-bus EHV equivalent system of the southern Indian grid are presented for illustrative purpose.
A New Linear Fractional Transformation Based Approach to Power System Robustness Analysis
Authors: Castellanos Bustamante Rafael , Roman Messina Arturo , Juarez Carlos
Published: November 2007

Large power systems are highly complex systems that defy predictions with any degree of certainty. In this paper, an analytical framework for the assessment of small signal stability under operating uncertainty is presented.A rigorous analysis framework for the description of uncertainty in operating conditions is suggested. Using structured singular value theory and optimization tools, techniques for robust stability analysis of complex power systems are then derived and a method to quantify the effect of parametric uncertainties on the stability of critical inter-area modes is presented. A computationally-efficient method for modeling parametric uncertainty based on linear fractional transformation (LFT) theory is investigated and tested. With this approach, it becomes possible to estimate the effects of variations in the parameters of major transmission resources on the nominal stability of critical inter-area modes.The use of the analysis methods is demonstrated on two systems: i) a two-machine test system, and ii) a two-area, 11-bus, 4-machine test system.
Novel Configuration of 60-Pulse Voltage Source Converter for STATCOM Application
Authors: Pan Wulue , Xu Zheng , Zhang Jing
Published: November 2007

The proposed voltage source converter is composed of a series double bridge converter with an auxiliary circuit. The auxiliary circuit injects DC voltage via the mid point of the double bridge converter. The injection ratio and frequency are chosen to convert the standard 12-pulse into 60-pulse configuration without PWM or increasing the number of bridges, thus the voltage and current harmonic can fulfill the THD limit without a conventional filter. The converter is operated under fundamental frequency for the main bridges, thus its switching lose is low. The converter can be widely used in the STATCOM and HVDC system. The paper describes the principles and control strategies of the proposed converter. The operational feasibility of the proposed converter is verified by computer simulation using the PSCAD/EMTDC package.
Islam and the European Project
Authors: Cavanaugh Kathleen
Published: November 2007

There exists a limited pluralist model of regulating or `managing' religious diversity in contemporary Europe. This pluralist model, however, is in contrast to the limitations that appear at the state level, which reflect an increasingly illiberal, secular Europe. Such contrast stems historically from tensions that exist between the national and transnational aspects of the model itself, but it also reflects the emerging debates on religious pluralism and the democratic state. With the settlement of post-colonial migrants (with Muslims constituting a large majority) a public debate on the role of religion in Europe has resurfaced as these communities exist outside the historical formation of Western church-state relations and are challenging the very underpinning of what comprises a `liberal' democratic state. In particular, it is the role of Islam in secular Europe that frames several questions in this debate: to what extent is it necessary to regulate religious freedoms in the `public sphere' in order to protect the democratic state? What restrictions on minority religions should be considered `necessary in a democratic society and what limitations should be placed on state interference in minority religions as protection against the undue influence of a dominant social group? Against this backdrop, this article explores the historical social formation of religious pluralism in the European context and examines the legal and political frameworks at the national and regional levels to `regulate' diversity.
The Development and Evaluation of a Four-roller Flour Mill with Parallelogram Configuration
Authors: Famurewa John Alaba Victor
Published: November 2007

A roller mill was designed and evaluated using four equal size cylindrical rollers with their centers on vertices of a parallelogram. The relative speeds and opposite direction of rotation of the rollers allowed the discharge of the materials on them, and splitting took place in between the first pair of corrugated rollers. The broken seeds were directed towards the second and third nips where adequate size reduction was accomplished consecutively by smooth rollers. The milled products were separated into three fractions: chaff, flour and size larger than flour. The chaff and the flour are collected at different outlets, while the particles with sizes larger than flour are blown back into the hopper for further reduction. The mill was evaluated using three grains: maize, beans and soy beans at different combinations of evaluating parameters. The machine was able to mill grains to flour size without any leakage at the nip points. For all the grains, a wide gap set produced higher throughput than narrow, as well as fast feeding in smaller particle size and higher throughput. The results obtained from the evaluation showed that the machine is very capable of three-stage size reduction to produce flour, avoiding the feeding problems in three high roller mills. Sieve analysis of the milled product for each experiment showed uniform particle size.
Adsorption Characteristics of Anthocyanins from Purple-fleshed Potato (Solanum tuberosum Jasim) Extract on Macroporous Resins
Authors: Liu Xuan , Xu Zhenghong , Gao Yangxiang , Yang Bin , Zhao Jian , Wang Lijun
Published: November 2007

The adsorption characteristics of anthocyanins from purple-fleshed potatoes on 11 macroporous SDVB, acrylic and methacrylic resins were investigated. Anthocyanins were first extracted from purple-fleshed potatoes using dilute acid solutions, and then partially purified by membrane filtration, which resulted in the removal of more than 90% of the total sugar and proteins from the crude extract. The partially purified extract were mixed with the resins at varying extract/resin ratios until equilibrium adsorption was reached and the adsorption data were fitted to the Langmuir and Freundlich isotherms. Both models were found suitable to describe the adsorption isotherms of anthocyanins on the resins tested. Adsorption capacities for anthocyanins increased with the rise of temperature for SDVB resins but decreased for metharcylic resins. The resin with the highest adsorption capacity for anthocyanins was XAD-1600, on which anthocyanin adsorption was an endothermic process and favored at higher temperature.
Some Physical and Mechanical Properties of Kiwifruit
Authors: Razavi Seyed Mohammad Ali , BahramParvar Maryam
Published: November 2007

In this paper, the physical properties such as length, width, thickness, geometric mean diameter, arithmetic mean diameter, mass, true volume, apparent volume, true density, bulk density, porosity, sphericity, surface area, shell ratio, aspect ratio, static coefficient of friction and mechanical characteristics namely firmness, hardness, adhesiveness, adhesive force and total positive area in puncture test were determined for kiwifruit of the Hayward variety. These properties are necessary in the design of the equipment for harvesting, processing and transportation, separating and packing. The results showed that the length, width, thickness, arithmetic mean diameter, geometric mean diameter, sphericity and aspect ratio of kiwifruit varied from 55.5 to 82.3 mm, 46.8 to 54.8 mm, 41.5 to 52.4 mm, 49.8 to 60.99 mm, 49.56 to 59.28 mm, 71.95 to 90.48% and 62.67 to 89.20%, respectively. While the surface area determined by McCabe et al.'s and Jean & Ball's formula, and surface area measured by experimental method changed from 77.11 to 110.34 cm2, 48.74 to 95.95 cm2 and 83.29 to 108.71 cm2, respectively. The values of the fruit's true volume, apparent volume, true density, bulk density and porosity were between 85-120 cm3, 63.69-109.01 cm3, 940-1040 kg/m3, 544.73-572.17 kg/m3 and 39.70-45.5%, respectively. Furthermore, the unit mass and peel ratio of kiwifruits ranged from 75.18 to 135.32 g and 8.91 to 12.51%, respectively. On four different surfaces, namely plywood, galvanized iron sheet, glass and fiberglass, static coefficient of friction varied from 0.34 on glass to 0.49 against plywood. The average firmness, hardness, adhesiveness, adhesive force and total positive area of peeled fruits were 229.42 g, 367.49 g, 716.48 g.s, -34.2 g and 11933.5 g.s, respectively. Corresponding values for unpeeled samples obtained 403.38 g, 2081.2 g, -3175.32 g.s, -118 g and 35757.22 g.s, respectively.
Exercise Imagery: A Systematic Review of the Empirical Literature
Authors: Kossert Amy L , Munroe-Chandler Krista
Published: November 2007

A systematic review was conducted on the utilisation of mental imagery in its contribution to improvements in exercise performance and behaviour. Research into imagery use in exercise is in its infancy, and thus, there have been conceptual, measurement and methodological inconsistencies. The purpose of the current paper was to review the empirical literature thus far on exercise imagery. It was concluded that exercise imagery might indeed prove to be an effective tool in enhancing performance and adherence in physical activity programmes; however, the refinement of measurement tools is required in order to further evaluate its nature and efficacy. Furthermore, the employment of a recently developed conceptual model for the use of imagery in exercise offers a theoretical direction to future research contributions, and in the design of imagery interventions in the exercise domain.
Nonlinear Modelling Application in Distillation Column
Authors: Abdullah Zalizawati , Aziz Norashid , Ahmad Zainal
Published: November 2007

Distillation columns are widely used in chemical processes and exhibit nonlinear dynamic behavior. In order to gain optimum performance of the distillation column, an effective control strategy is needed. In recent years, model based control strategies such as internal model control (IMC) and model predictive control (MPC) have been revealed as better control systems compared to the conventional method. But one of the major challenges in developing this effective control strategy is to construct a model which is utilized to describe the process under consideration. The purpose of this paper is to provide a review of the models that have been implemented in continuous distillation columns. These models are categorized under three major groups: fundamental models, which are derived from mass, energy and momentum balances of the process, empirical models, which are derived from input-output data of the process, and hybrid models which combine both the fundamental and the empirical model. The advantages and limitations of each group are discussed and compared. The review reveals a remarkable prospect of developing a nonlinear model in this research area. It also shows the discovery of new advance methods in an attempt to gain a nonlinear model that is able to be used in industries. Neural network models have become the most popular framework in nonlinear model development over the last decade even though hybrid models are the most promising method to be applied for future nonlinear model development.
Development of Web Based Computer Package for the Simulation of Thermal Desalination Processes
Authors: Abdel-Jabbar Nabil , Mjalli Farouq S. , Qiblawey Hazim , Ettouney Hisham
Published: November 2007

A computer package based on visual basic code is developed for single and multiple effect evaporation desalination systems (SEE and MEE). The package features design calculations of heat transfer area, power consumption, and costing. The package is user-friendly and is equipped with interactive menus for report and form printing, file saving and retrieving, help files, and tutorial. The computer code is designed to run a default design case and also allows the user to change variables within pre-specified practical ranges. A rigorous process model is used in the package, which is based on detailed fundamental material and energy balance equations, well-proven correlations for the heat transfer coefficients, physical properties, and thermodynamic losses. Illustrations of the package displays are presented together with a number of case studies. Model predictions generated from the code are validated against actual field data and they showed a very good agreement. Future plans involve development of design simulator for the multistage flash desalination (MSF) and reverse osmosis (RO).
Simulation of the Coke Calcining Processes in Rotary Kilns
Authors: Elkanzi Elamin Mohamed
Published: November 2007

The objective of this study is to simulate the green petroleum coke calcining processes using the simulation program HYSYS and using actual industrial data. Because counter-current mass flow is not allowed in the HYSYS program, the kiln was described by using fictive streams and unit operations. By the simulation, it is possible to predict the operating conditions that control the contents of undesirable impurities in the calcined petroleum coke, namely, sulfur, volatile matter and moisture contents. It also gives the desirable calcined petroleum coke properties such as density. Apart from the metal contents, the simulation allows the coke calciner to utilize any type of green coke regardless of the undesirable impurities. This is done without resorting to the costly blend from different types of green cokes. Simulation is also effective in controlling and optimizing calcination processes' variables. From the simulation it was found that it is possible to process any type of green coke for varying sulfur, volatile matter and water content by adjusting the amount of tertiary air and/or fuel. Two simulation cases were studied for low and high volatile matter contents of 8.5 and 14.7 wt% in the feed. Mass flow rates of fuel and tertiary air were both increased in the first case, while no fuel was required in the second case. The benefit from this is to reduce the operating costs.
Free Cash Flow and Managerial Entrenchment: A Continuous-Time Stochastic Control-Theoretic Model
Authors: Cadenillas Abel , Clark Steven P
Published: November 2007

In this paper, we formulate a model prescribing optimal policy for cash disbursements and seasoned equity offerings taking into account the principal-agent problems inherent in these decisions. In order to discipline managers, stockholders demand that excess free cash flow be disbursed either as cash dividends or through stock repurchases. Managers resist stockholders in this regard since they prefer to retain excess free cash flow in order to pursue personal interests and reduce the probability that the company will experience financial distress in the future. However, as a consequence of withholding cash disbursements, managers incur disutility due to the possibility that their control of the firm could be threatened by the market for corporate control. We model this situation as a stochastic impulse control problem, and succeed in finding an analytical solution. We derive several testable implications, some of which have not been fully addressed in the corporate finance literature.
Modeling of the thyme: Liquid carbon dioxide extraction system
Authors: Zekovic Zoran , Lepojevic Zika , Milosevic Svetlana , Tolic Aleksandar
Published: November 2007

The extraction of thyme (Thymus vulgaris L) by liquid carbon dioxide was investigated. The obtained extracts were analyzed by HPLC and GC-MS methods, and their composition was compared with that of the essential oil obtained by steam distillation and by supercritical carbon dioxide at 100 bar and 40?C. To model extraction of the thyme - liquid carbon dioxide system, we used the Reverchon - Sesti Osseo equation, as well as our modified equation.
The effect of sulphates on partitioning of pectinases in aqueous two-phase systems
Authors: Antov Mirjana , Pericin Draginja , Trbojevic Biljana
Published: November 2007

The effect of various sulphate salts on the partitioning of endo-pectinase and exo-pectinase in aqueous two-phase systems, composed of polyethylene glycol and dextran, was studied. Presence of ammonium sulphate and sodium sulphate at concentration 15 mmol/l in the system polyethylene glycol 4000/crude dextran, at tie-line length 7.44%, increased partition coefficient of endo-pectinase 1.25 and 1.2 fold, respectively. Ammonium sulphate at 15 mmol/l and sodium sulphate at 5 mmol/l enhanced partition coefficient for exo-pectinase for about 60% in comparison to the system without salts. Addition of magnesium and sodium sulphate to a final concentration of 0.3 mmol/l in the system containing polyethylene glycol 6000/dextran 500 000, at tie-line length 6.26%, increased the partition coefficient of endo activity for 95% and 32%, respectively. Both salts at the same concentration increased partition coefficient of exo activity 1.5 and 3 times, respectively, in comparison to the system without salts.
TLC analysis of some phenolic compounds in kombucha beverage
Authors: Malbasa Radomir , Loncar Eva , Kolarov Ljiljana
Published: November 2007

Black and green tea contains a wide range of natural phenolic compounds Flavanoids and their glycosides, catechins and the products of their condensation, and phenolic acids are the most important. Kombucha beverage is obtained by fermentation of tea fungus on black or green tea sweetened with sucrose. The aim of this paper was to investigate the composition of some phenolic compounds, catechin, epicatechin, quercetin, myricetin, gallic and tanic acid, and monitoring of their status during tea fungus fermentation. The method used for this study was thin layer chromatography with two different systems. The main phenolic compounds in the samples with green tea were catechin and epicatechin, and in the samples with black tea it was quercetin.
Physico-chemical characterization of mixed-ligand complexes of Mn(III) based on the acetylacetonate and maleic acid and its hydroxylamine derivative
Authors: Cakic Suzana , Nikolic Goran , Stamenkovic Jakov , Konstantinovic Sandra
Published: November 2007

Two new Mn(III) mixed-ligand complexes with two acetylacetonate (acac) ligands and one maleate ligand and its hydroxylamine derivative of the general formula [Mn(C5H7O2)2L] were prepared. Their structure was established by using elemental analysis, FTIR and UV/VIS spectroscopic methods, as well as magnetic measurement. Replacement of the acetylacetonate ligand by the corresponding acid ligand has been confirmed in Mn(III) acetylacetonate. Based on the obtained experimental data and literature indications, structural formulae to these compounds were assigned.
Batch fermentation of black tea by kombucha: A contribution to scale-up
Authors: Malbasa Radomir , Loncar Eva , Djuric Mirjana , Kolarov Ljiljana , Klasnja Mile
Published: November 2007

Local domestic Kombucha was used in fermentation of 1.5 g L-1 of black tea (Indian tea, " Vitamin ", Horgos, Serbia and Montenegro), sweetened with approximately 70 g L'1 of sucrose. Inoculation was performed either with 10% or 15% (v/v) of fermentation broth from previous process. The fermentation was conducted in geometrically similar vessels with 0.4 L, 0.8 L, 4 L and 8 L of substrate, at 22?1 ?C for 28 days. The samples were analyzed after 3, 4 5, 6, 7, 10, 14 and 28 days, so that their pH values, content of total acids sucrose, glucose and fructose contents, as well as contents of ethanol and vitamin C were determined. Based on the experiment design, the response surface for the product pH, as a function of time, beverage volume and inoculum concentration, was defined in the form of a second-order polynomial. From the obtained response surface, a formula for scaling-up of the process was derived.
Analysis of forensic samples of "Ecstasy" tablets seized in Novi Sad during the 2004 year
Authors: Zgonjanin Dragana , Loncar Eva , Tasic Milos
Published: November 2007

The paper presents results of the analysis of illicit synthetic drugs in the form of tablets distributed under the name "Ecstasy", seized by the police in the broader area of Novi Sad 2004. A huge number of tablets has been analyzed (n=121), of various colours and with impressed symbols from the total amount of 93 seizures, which totally amounted to 1458 tablets. Regarding the number of seizures ecstasy (3,4-methylendioxy-N-meth-yl-amphetamine - MDMA) is dominant among all, and according to the quantity of seized tablets it is amphetamine (AP), while other amphetamine-type drugs (methamphetamine MA 3,4-methylendioxiamphetamine - MDA, 3,4-methylendioxi-N-ethyl-amphetamine MDEA) have been found in rather small quantities and very rarely. Tablets mostly contain caffeine as an additive. In the analytical procedure, the samples of tablets were subjected to liquid-liquid extraction and afterwards analyzed on the GCD (GC-EI) Hewlett-Packard instrument. The method is fast reliable and reproducible for the analysis of amphetamine, methamphetamine MDA, MDMA, MDEA, as well as various additives in the samples of seized tablets.
Role of strong focusability on the welding process
Authors: Weberpals Jan , Dausinger Friedrich , Göbel Gunther , Brenner Berndt
Published: November 2007

Thin disk lasers as well as fiber lasers are distinguished by their strong focusability and high efficiency. With the availability of such laser sources in a high power region, keyhole welding with very small focus diameters down to 50 μm became possible. Typical focus diameter regimes of such laser sources can now be compared with regard to their effect on welding depth and process efficiency. Based on results of thin disk laser experiments it has been shown in earlier publications that the influence of the divergence angle on the achievable welding depth increases dramatically for lower spot diameters. This effect stands in contrast to the behavior at higher spot diameters, but was now confirmed by additional experiments with a fiber laser which made available smaller divergence values. No influence of focus diameter and divergence angle on the reachable cross sectional area for both laser systems has been observed, on the other hand. That means that in the investigated parameter range the process efficiency of keyhole welding is in fact independent of the focusability of the laser source.
Structuring electrospun polycaprolactone nanofiber tissue scaffolds by femtosecond laser ablation
Authors: Choi Hae woon , Johnson Jed K. , Nam Jin , Farson Dave F. , Lannutti John
Published: November 2007

Meshes of electrospun (ES) polycaprolactone (PCL) and polyethylene terephthalate nanofiber meshes were structured by ablation of linear grooves with a scanned femtosecond laser. Focus spot size, pulse energy, and scanning speed were varied to determine their affects on groove size and the characteristics of the electrospun fiber at the edges of these grooves. The femtosecond laser was seen to be an effective means for flexibly structuring the surface of ES PCL scaffolds. Femtosecond ablation resulted in much more uniformly ablated patterns compared to Q-switched nanosecond pulse laser ablation. Also, the width of the ablated grooves was well controlled by laser energy and focus spot size, although the grooves were significantly larger than the spot size. Also, some melting of fibers was observed at the edges of grooves. These affects were attributed to optical radiation from laser-induced plasma at higher pulse energies and melting of fibers at laser fluences lower than the ablation threshold. The ablation threshold for the PCL mesh was estimated to be significantly larger than that of bulk (solid) PCL, a result attributed to multiple scattering of the laser energy within the volume of the nanofiber mesh.