bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling of a Flat Plate, Slurry Reactor for the Photocatalytic Degradation of 4-Chlorophenol
Authors: Satuf María Lucila , Brandi Rodolfo J , Cassano Alberto E , Alfano Orlando M
Published: November 2007

Heterogeneous photocatalysis employing titanium dioxide has emerged as an efficient method to remove a wide range of toxic compounds from polluted waters. In particular, chlorophenols constitute an important group of aquatic contaminants that have been successfully degraded by photocatalysis. In this work, the modeling of a slurry reactor for the photocatalytic degradation of 4-chlorophenol (4-CP) is presented. The experimental reactor is a thin rectangular parallelepiped limited by two parallel windows made of borosilicate glass. It is illuminated from one side by two tubular UV lamps (UV Philips TLK40/09N) located at the focal axis of cylindrical reflectors of a parabolic cross-section. The flat plate reactor is placed inside the loop of an isothermal, batch recycling system. The model describes the degradation of 4-CP as well as the formation and disappearance of the main intermediate products: 4-chlorocatechol (4-CC) and hydroquinone (HQ). Intrinsic kinetic expressions, previously obtained in a laboratory scale reactor, were employed to solve the mass balance for each species. To take account of the radiation effects on the reaction rate, the radiative transfer equation was solved in the flat plate reactor. The radiation model involves two spatial variables and two angular variables in the direction of radiation propagation.To validate the model, experimental runs were conducted by varying the catalyst loading (0.05, 0.1, 0.5, 1.0 x 10-3 g/cm3) and the 4-CP initial concentration (0.7 and 1.4 x 10-7 mol/cm3). Good agreement was found between simulation results and experimental data. Based on the experimental and predicted concentrations of 4-CP and 4-CC, the root mean square error (RMSE) of the model was 9.9 %.
Development of Alternative Catalysts Based on HZSM-5 Zeolite for the BTO Process
Authors: Alonso Ainhoa , Valle Beatriz , Atutxa Alaitz , Gayubo Ana Guadalupe , Aguayo Andres
Published: November 2007

The catalytic behaviour of a commercial HZSM-5 zeolite (Si/Al=30) for the selective transformation of bio-ethanol into olefins (BTO process) has been improved by two alternative methods: a) treatment with 0.2M alkali solution for a short time; and b) impregnation with Ni. By means of experimentation in an isothermal fixed bed reactor connected on-line to a GC for the analysis of the reaction products, it has been proven that moderate alkali treatment (10 min) slightly modifies the superficial structure and acidity of the HZSM-5 zeolite, which provokes a significant increase in the concentration of C2-C4 olefins, whereas deactivation rate and hydrothermal stability are similar. Moreover, 1 wt% nickel content in the catalyst is the optimum in order to obtain the better compromise concerning hydrothermal stability of the catalyst, coke deactivation, total yield of olefins and selectivity to C3-C4 olefins in the 400-500 °C range. In fact, the average production rate of C3-C4 olefins is twice as high as that of the parent zeolite in 8 h time on-stream experiments at 450 °C and 75wt% water content in the feed. Both methods are highly interesting because of the simplicity and reproducibility for obtaining economic and selective catalysts for the BTO process at moderate temperatures (catalysts modified by alkali treatment) and high temperatures (nickel based catalysts).
Co-Cu Metal Alloys from LaCo1-xCuxO3 Perovskites as Catalysts for Higher Alcohol Synthesis from Syngas
Authors: Nguyen T.T. , Zahedi-Niaki M.H. , Alamdari H. , Kaliaguine S.
Published: November 2007

The specific surface area of ground perovskites is strongly dependent on the synthesis and pretreatment conditions. Calcining the ground LaCo1-xCuxO3-? perovskites at 5000C causes a decrease of their specific surface, but the further reductive pretreatment of the calcined sample in hydrogen leads to only a minor change in the specific surface area.The introduction of extra- and intra-perovskite lattice copper has different effects on the structure stability, reducibility and catalytic properties of LaCoO3 perovskites. Under the same pretreatment conditions the basic structure of both LaCoO3 and Cu2O/LaCoO3 samples is retained at the reduction temperature of 5000C (90 min) while that of Co-Cu based perovskites is completely collapsed producing a high dispersion of bimetallic metals and Co-Cu alloys supported on amorphous La2O3. For a series of LaCo1-xCuxO3 samples, increasing the copper content in the perovskite structure leads to an increase in the metal surface area of the reduced phase. The pretreated catalysts were tested for CO dissociation and for alcohol synthesis from syngas. The results indicated that the copper sites neighboring with cobalt atoms in the reduced perovskites decrease the activity in CO dissociation and increase the rate of higher alcohol synthesis while extra-perovkite lattice copper tends to produce methanol, methane and CO2. The overall activity in syngas conversion and higher alcohol productivity are proportional to the Co-Cu metal surface. The role of dual sites of Co and Cu for the synthesis of higher alcohols is discussed. The catalytic activity and alcohol productivity as well as product distribution depend strongly on reaction temperature and pretreatment conditions. The highest productivity of alcohols in the present study is about 73 mg/gcat/h for sample LaCo0.7Cu0.3O3.
Modeling and Optimization of M-cresol Isopropylation for Obtaining N-thymol: Combining a Hybrid Artificial Neural Network with a Genetic Algorithm
Authors: Benjamin Yao Kouassi , Nogbou Emmanuel Assidjo , Ado Gossan , Azzaro-Pantel Catherine , Davin André
Published: November 2007

The application of a hybrid framework based on the combination, artificial neural network-genetic algorithm (ANN-GA), for n-thymol synthesis modeling and optimization has been developed. The effects of molar ratio propylene/cresol (X1), catalyst mass (X2) and temperature (X3) on n-thymol selectivity Y1 and m-cresol conversion Y2 were studied. A 3-8-2 ANN model was found to be very suitable for reaction modeling. The multiobjective optimization, led to optimal operating conditions (0.55 ? X1 ? 0.77; 1.773 g ? X2 ? 1.86 g; 289.74 °C ? X3 ? 291.33 °C) representing good solutions for obtaining high n-thymol selectivity and high m-cresol conversion. This optimal zone corresponded to n-thymol selectivity and m-cresol conversion ranging respectively in the interval [79.3; 79.5]% and [13.4 %; 23.7]%. These results were better than those obtained with a sequential method based on experimental design for which, optimum conditions led to n-thymol selectivity and m-cresol conversion values respectively equal to 67% and 11%. The hybrid method ANN-GA showed its ability to solve complex problems with a good fitting.
The Cyclohedron Test for Finding Periodic Genes in Time Course Expression Studies
Authors: Morton Jason , Pachter Lior , Shiu Anne , Sturmfels Bernd
Published: November 2007

The problem of finding periodically expressed genes from time course microarray experiments is at the center of numerous efforts to identify the molecular components of biological clocks. We present a new approach to this problem based on the cyclohedron test, which is a rank test inspired by recent advances in algebraic combinatorics. The test has the advantage of being robust to measurement errors, and can be used to ascertain the significance of top-ranked genes. We apply the test to recently published measurements of gene expression during mouse somitogenesis and find 32 genes that collectively are significant. Among these are previously identified periodic genes involved in the Notch/FGF and Wnt signaling pathways, as well as novel candidate genes that may play a role in regulating the segmentation clock. These results confirm that there are an abundance of exceptionally periodic genes expressed during somitogenesis. The emphasis of this paper is on the statistics and combinatorics that underlie the cyclohedron test and its implementation within a multiple testing framework.
Reforming the IMF
Authors: Morgan John
Published: November 2007

John Morgan presents a radical proposal to sell voting rights at the IMF and redistribute power through market mechanisms instead of by formula.
The Effects of Honey Compared With Sucrose and a Sugar-free Diet on Neutrophil Phagocytosis and Lymphocyte Numbers after Long-term Feeding in Rats
Authors: Chepulis Lynne M
Published: November 2007

To determine whether honey and sucrose would have differential effects on levels of neutrophil phagocytosis after long-term feeding 36 2-month old Sprague Dawley rats were fed a powdered diet that was either sugar-free or contained 7.9% sucrose or 10% honey (honey is 21% water) ad libitum for 52 weeks. The percent of neutrophils exhibiting phagocytosis, and the percentage of leukocytes that were lymphocytes were then measured by flow cytometry after 52 weeks. Results: Neutrophil phagocytosis was similar between sucrose- and honey-fed rats, and lower in rats fed the sugar-free diet (79.2%, 74.7% and 51.7 %, respectively). The percentage of leukocytes that were lymphocytes differed significantly between all three treatments, the levels being highest in honey-fed rats (53% vs 40.1% and 29.5% for sucrose- and sugar-free fed rats). In conclusion: Honey may have a beneficial effect on immune activity, possibly attenuating the decline seen in older age.
Time-Frequency Spectrum Analysis of Very Fast Transient Currents (VFTC) Generated in a GIS
Authors: Rao Mandava Mohana , Thomas M. Joy , Singh B.P.
Published: November 2007

Very Fast Transient Overvoltages (VFTO) and the associated Very Fast Transient Currents (VFTC) generated during switching operations in a Gas Insulated Substation (GIS) couple conductively and inductively to the secondary equipment connected to the GIS. The frequency spectrum of the VFTC gives the dominant frequencies present but cannot provide the time varying current amplitude w.r.t. any particular frequency. Since the transient response of the control circuits is a function of the frequency content of the VFTC, it becomes necessary to segregate the VFTC waveform both in time and frequency scale simultaneously. This has been achieved by employing the GABOR wavelet function and the time-frequency spectrum of the VFTC waveform has been calculated at various locations for a 245 kV GIS during a switching event. The validity of the wavelet model is confirmed by reconstructing the VFTC signal at the GIS-cable termination as well as at the switching point using the time varying current waveforms obtained for different frequencies. Finally, the transient current vs frequency as well as the current vs distance charts are developed for the 245 kV GIS under study during various switching operations.
A Novel Modulated Power Filter Compensator for Distribution Networks with Distributed Wind Energy
Authors: Sharaf Adel M , Wang Weihua , Altas Ismail H.
Published: November 2007

During the last two decades, renewable wind energy has become increasingly popular as a consequence of strong ecological concerns and appealing advantages with regard to economical energy solutions in remote communities. Furthermore, with very large wind farms emerging, the dispersed renewable wind energy is required to be fully connected to the electrical distribution networks. However, the integration of dispersed renewable wind energy will pose a great challenge to the power quality in the distribution networks when the weak nature of the grid in remote areas and the uncertainty of wind are taken into consideration.This paper presents a novel Modulated Power Filter Compensator (MPFC) for the distribution networks with dispersed renewable wind energy interfaced. A tri-loop error driven controller is used to adjust the PWM switching of the modulated power filter compensator. Full power factor correction and power quality improvement is validated under different operation conditions, like load switching and wind velocity excursions. The MPFC device is a member of novel FACTS based compensators developed by the first author.
Fuzzy Expert Approach with Curtailed Controllers for Improved Reactive Power Dispatch
Authors: Dhadbanjan Thukaram , Yesuratnam G.
Published: November 2007

This paper addresses the problem of curtailing the number of control actions using fuzzy expert approach for voltage/reactive power dispatch. It presents an approach using fuzzy set theory for reactive power control with the purpose of improving the voltage profile of a power system. To minimize the voltage deviations from pre-desired values of all the load buses, using the sensitivities with respect to reactive power control variables form the basis of the proposed Fuzzy Logic Control (FLC). Control variables considered are switchable VAR compensators, On Load Tap Changing (OLTC) transformers and generator excitations. Voltage deviations and controlling variables are translated into fuzzy set notations to formulate the relation between voltage deviations and controlling ability of controlling devices. The developed fuzzy system is tested on a few simulated practical Indian power systems and modified IEEE-30 bus system. The performance of the fuzzy system is compared with conventional optimization technique and results obtained are encouraging. Results obtained for a modified IEEE-30 bus test system and a 205-node equivalent EHV system a part of Indian southern grid are presented for illustration purposes. The proposed fuzzy-expert technique is found suitable for on-line applications in energy control centre as the solution is obtained fast with significant speedups with few number of controllers.
A Hybrid Decision Tree Model for Fast Voltage Contingency Screening and Ranking
Authors: Patidar Narayan Prasad , Sharma Jaydev
Published: November 2007

This paper presents a new decision tree (DT) based approach for fast voltage contingency screening and ranking for on-line applications in energy management systems. The hybrid decision tree model is developed to learn all the selected contingencies simultaneously, therefore fewer DTs are required. To reduce the size and improve the accuracy of the decision tree, the K-class problem is converted into the set of K two-class problems, and separate decision tree modules are trained for each of the two class problems. All the selected contingencies are presented to the filter module, which is trained to separate them in critical and non-critical contingency classes, which reduces the burden on ranking modular DT. The critical contingencies screened out by the filter module are presented to the ranking modular decision tree for their further ranking. To measure the severity of contingencies, bus voltage violation based scalar performance index is used. Full AC load flow is performed to generate the training and testing patterns for the proposed hybrid decision tree, under each contingency. The effectiveness of the proposed approach is tested on IEEE test systems. Once trained, a hybrid decision tree method gives fast and accurate screening and ranking of contingencies for unknown load patterns.
A Novel Load Compensation Algorithm under Unbalanced and Distorted Supply Voltages
Authors: Karthikeyan K. , Kumar Mishra Mahesh
Published: November 2007

In this paper, a novel control algorithm is proposed to compensate the unbalanced and non-linear loads in a three-phase four-wire system using active power filters. The algorithm results in balanced and sinusoidal source currents under unbalanced and distorted three-phase supply voltages. The algorithm makes use of the positive sequence extraction of the supply voltage and the theory of instantaneous symmetrical components. To illustrate the concept, a three-phase four-wire system with unbalanced and non-linear load is considered for compensation. The detailed simulation and experimental results are presented to validate the proposed method.
The Politics and Hermeneutics of Hijab in Iran: From Confinement to Choice
Authors: Mir-Hosseini Ziba
Published: November 2007

Hijab  covering of a Muslim woman's body  is the most visible Islamic mandate. For a century it has been a major site of ideological struggle between traditionalism and modernity, and a yardstick for measuring the emancipation or repression of Muslim women. In recent decades hijab has become an arena where Islamist and secular feminist rhetoric have clashed. For Islamists, hijab represents their distinct identity and their claim to religious authenticity: it as a divine mandate that protects women and defines their place in society. For secular feminists, hijab represents women's oppression: it is a patriarchal mandate that denies women the right to control their bodies and to choose what to wear. The clash has been particularly strident in Iran, where the state has twice intervened with legislation to an extent that no other Muslim country has experienced. Iran, too, has been a prime site for the emergence of `Islamic feminist' discourses that speak of hijab not as a `duty,' but as a `right,' and as a social rather than a religious mandate, and finds juristic arguments to support this position. This article traces the genealogy of this new juristic position from notions of hijab in classical Islamic jurisprudence (fiqh). It documents how jurisprudential positions and notions of hijab in Iran evolved in response to socio-political factors. It concludes by highlighting wider implications of the new juristic position on hijab for establishing common ground between secular feminist and Islamic discourses.
The Islam and Human Rights Nexus: Shifting Dimensions
Authors: Mayer Ann Elizabeth
Published: November 2007

The Islam and human rights nexus is too often viewed as being static. In reality, the relationship is complex and mutable. In an era of unsettling changes to the status quo, perceptions of the Islam and human rights nexus have also proven to be sensitive to shifting political dynamics. In these circumstances, the position that Islam and human rights are inherently in conflict, which assumes two settled entities in a stable relationship, is becoming hard to sustain  as is the position that human rights are ineluctably tied to Western civilization. Many Muslims are arguing that Islam and human rights are harmonious, and human rights contain principles that address some of Muslims' most pressing concerns. However, there are also factors  such as certain U.S. policies - that could work in the opposite direction, energizing Islamist hostility to human rights and confirming Muslims' suspicions that human rights are part of a nefarious Western plot. We must recognize that the Islam and human rights relationship is regularly readjusting in response to a changing environment, so that the issues addressed over the next decades will not likely be the same ones that Muslim societies and Islamic thinkers have been wrestling with to date.
Physicochemical Properties of the Josapine Variety of Pineapple Fruit
Authors: Shamsudin Rosnah , Daud Wan Ramli Wan , Takriff Mohd Sobri , Hassan Osman
Published: November 2007

Several parameters related to the physicochemical properties of Josapine pineapple juice, such as moisture content, total soluble solids (TSS), pH, color, water activity, freezing point, sugar content and acidity, were evaluated over a week of ambient storage at 25oC and 52% RH. The results indicated that Josapine pineapples take about 11 days to progress from maturity stage 1 to stage 7. The moisture content of fruit increased from 93.5% wb to 95.1% wb over the 11 days period. Analysis on the color of the juice showed the color space coordinate parameter b varies between 9.11 to 15.8, parameter a increased from 3.33 to 3.68 and the 'L' value decreased from 39.46 to 38.7 at the initial ripening stage but increased to 40.9 in the later stages. The TSS increased at the early ripening stage but decreased toward the end of ripening period. Freezing point, water activity and pH of juice range were 2.77 to  2.90 oC, 0.988 to 0.997 and 3.81 to 4.10 respectively. The total sugar and acidity in juice range were 12.5 to 17% and 0.69 to 0.90% respectively. The TSS/acid ratio of juice range was 12.32 to 18.60. The data presented in this work demonstrate the relationship between physicochemical properties of Josapine pineapples and the ripening process.
Improvement in Food Packaging Industry with Biobased Nanocomposites
Authors: Akbari Zahra , Ghomashchi Talat , Moghadam Shahin
Published: November 2007

Nanotechnology will become one of the most powerful forces for innovation in the food packaging industry. One such innovation is biobased nanocomposite technology, which holds the key to future advances in flexible packaging. Biobased nanocomposites are produced from incorporation of nanoclay into biopolymers (or Edible films). Advantages of biobased nanocomposites are numerous and possibilities for application in the packaging industry are endless. A comprehensive review of biobased nanocomposite applications in food packaging industry should be necessary because nanotechnology is changing rapidly and the food packaging industry is facing new challenges. This provides a general review of previous works. Many of the works reported in the literature are focused on the production and the mechanical properties of the biobased nanocomposites. Little attention has been paid to gas permeability of biobased nanocomposites. In regard to extensive research on Edible film, this article suggests investigating the replacement of biobased nanocomposites instead of Edible films in different areas of food packaging.
Yeast Inactivation in Fresh Apple Juice by High Pressure Nitrous Oxide
Authors: Spilimbergo Sara , Mantoan Denise , Cavazza Agostino
Published: November 2007

High-pressure CO2 processing is one of the emerging preservation technologies designed to produce safe food, while maintaining its nutritional and sensory qualities. The effects of dense nitrous oxide processing parameters, including pressure (60-200 bar) and treating times (1-25 min) on yeast survival in apple juice were investigated. Experiments performed in multi-batch equipment at 36°C, confirm the effectiveness of the high pressure technology. N2O led to a complete yeast inactivation in 5 minutes, achieved at 100 bar and 36°C.As the inactivation hypotheses are concerning, some issues regarding N2O chemical nature, its interaction with lipids and cell membrane modification were discussed.Dense phase CO2/N2O processing can be an effective non-thermal alternative process for the pasteurization of apple juice.
Some Physical and Mechanical Properties of Garlic
Authors: Bahnasawy Adel H.
Published: November 2007

The physical parameter results showed that the garlic geometric and arithmetic mean diameters ranged from 2.53 to 4.93, and 2.53 to 5.02 cm, respectively according to the bulb size categories. The cloves' length, width and thickness were 1.92 to 2.91, 0.78 to 1.32, and 0.69 to 0.99 cm, respectively. The surface and cross-sectional of areas ranged from 53.31 to 136.4 and 29.1 to 128.4 cm2, respectively. The number of cloves ranged from 18 to 51/bulb according to the bulbs size categories. Bulk density, repose angle and coefficient of contact surface values ranged from 892 to 1007 kg/m3, 41.52 to 45.04º, and 0.91 to 1.12, respectively, according to the bulb size categories.The chemical properties showed that the emptying (friction) angle ranged from 23.25 to 28.82º, where small bulbs recorded the highest values on the concrete surfaces, while the lowest values were recorded by the large bulbs on the iron surfaces. The friction coefficient decreased with increasing bulb size, where it was the highest (0.8) for the small bulbs on the concrete surfaces; on the other hand, the lowest values (0.36) were recorded for the large bulbs on the iron surfaces. The crushing load of the cloves ranged from 55.6 to 155.0 N, depending on the bulb size. The force required for loosening the cloves from the bulb ranged from 110 to 272 and 101 to 320 N on the horizontal and vertical positions of the bulbs.
Texture Profile Analysis of Cooked Sun Dried Nuggets (Bori) Prepared with Different Levels of Moisture Content and Percent Air Incorporation in Its Batter
Authors: Swami Shrikant Baslingappa , Das Susanta Kumar , Maiti Biswajeet
Published: November 2007

In this paper the texture profile analysis for the cooked Bori nuggets (traditional Indian food) prepared from black gram batter having different initial moisture content of 62 to 72% (wb) and air incorporation of 14.14 to 18.12% (v/v) is discussed. The initial moisture content and the volume of air incorporation into the batter had significant effect at either 5% or 1% level of significance on the springiness, chewiness, hardness, cohesiveness and gumminess of the cooked nuggets. The optimum initial moisture content of 65.10 to 67.15% (wb) in the batter and air incorporation of 15.91 to 17.23% (v/v) in it are recommended in obtaining the maximum and minimum levels of the response quality parameters. The optimum values of these response parameters would be 0.453, 12.22, 60.31 N, 0.36 and 22.36 for springiness, chewiness, hardness, cohesiveness, and gumminess, respectively.
The Changes in the Lipid Composition of Mung Bean Seeds as Affected by Processing Methods
Authors: Abdel-Rahman El-Sayed Ali , El-Fishawy Fawzy A , El-Geddawy Mohamed A , Kurz Tomas , El-Rify Mohamed N
Published: November 2007

This study was conducted to assess in detail the possible effects of some technological processes such as soaking, germination, cooking, soaking + cooking, and germination + cooking on the lipid composition of mung bean seeds of Giza 1 variety. TLC analysis of mung bean lipids showed that the phospholipids and triglycerides recorded the highest percentage among lipid fractions (32.26 and 30.10%), while the 1,3 diglycerides constituted the least percentage (2.80%) in mung bean seeds. The soaking, germination and cooking processes caused a decrease in the phospholipids, triglycerides and hydrocarbons accompanied with an increase in monoglycerides, 1,2-(2,3)-diglycerides, sterols and free fatty acids. Eleven fractions were separated from phospholipids class of the studied samples; seven of these fractions were identified. The major component of phospholipids was phosphatidyl choline, amounting to 21.30, 17.84, 16.21, 13.87, 13.20 and 11.47% of the total phospholipids in raw, soaked, germinated, raw-cooked, soaked-cooked and germinated-cooked mung bean seeds, respectively. Gas liquid chromatography of the total lipids of mung bean seeds showed that the unsaturated fatty acids represented 69.58, 64.35, 63.3, 63.16, 61.84 and 61.12%, while the levels of saturated fatty acids were low being 30.37, 34.05, 35.66, 34.64, 37.93 and 38.75% of the total fatty acids in raw, soaked, germinated, raw-cooked, soaked-cooked and germinated-cooked, respectively. The total essential fatty acids (linoleic and linolenic) represented the highest proportion of fatty acids (50.10% of the total fatty acids).
A Qualitative Investigation of Imagery Use and Meta-Imagery Processes among Elite Canoe-Slalom Competitors
Authors: MacIntyre Tadhg E. , Moran Aidan P
Published: November 2007

Imagery research has accumulated in two main waves since it was first investigated over a century ago. Firstly, in a period roughly extending over a century from the 1890s to the 1990s, several hundred experiments focused on the efficacy of the "mental practice" effect. More recently, attempts to shed light on the precise tasks or functions for which athletes use visualization in actual sport situations have led to an upsurge in imagery research. Central to this second wave of research is the imagery use framework (Hall et al., 1998), which has led to over 20 studies. Unfortunately, despite making significant advances these studies have a number of limitations, including a failure to include elite participants and the fact that they have largely overlooked meta-imagery abilities of the athletes. To address these issues, semi-structured interviews were used to explore imagery experiences among elite athletes. Canoe-slalom, which had been subject to previous research on imagery (e.g., White & Hardy, 1998), was the chosen sport. Five female and seven male elite level competitors (age= 25 years; SD = 4.16) participated. Findings from the elite athlete sample were inconsistent with previous research with regard to the motivational function of images. Furthermore, the athletes demonstrated a sophisticated understanding of imagery processes including imagery of realistic behaviours rather than perfect performance. Interestingly, the frequency of debilitative imagery was surprising given previous findings but may have been a consequence of the qualitative methods employed. Finally, examination of the meta-imagery construct proved valuable and is worthy of further research.
Simulation and Analysis of Fluid Dynamic Behaviour of Foods during Filling Processes
Authors: Bottani Eleonora , Rizzo Roberto , Vignali Giuseppe
Published: November 2007

This research presents a model describing the behaviour of a non-Newtonian shear-thinning fluid during aseptic filling processes, in order to determine the influence of the behaviour of fluids on the performance of filling valves in aseptic beverage plants, mainly in terms of the time required to perform the filling process. The ultimate aim of the study is to explore the possibility of improving the accuracy of industrial filling processes, so as to be able to utilise them with high viscosity fluids.The numerical model, exploiting the Finite Elements Method (FEM), was designed using the commercial software Comsol Multiphysics, and validated by comparing the steady state predictions with outcomes of filling experiments performed in industrial laboratories. Hence, subsequent numerical simulations were performed to investigate the transition from laminar to turbulent flow for shear-thinning fluids under different pressure conditions, in 3D time-dependent configurations. Results of the simulations, performed on a low fat yoghurt, show that laminar flow subsists within the whole filling system when the Metzner-Reed Reynolds number at the inlet section of the valve is lower than approx 444.
Optimal Prevention when Informal Penalties Matter: The Case of Medical Errors
Authors: Grepperud Sverre
Published: November 2007

Individuals often respond with strong emotions to being penalised. Such responses suggest that informal penalties are important and play a role in creating deterrence. In this paper informal penalties are analysed in the context of medical errors. The introduction of informal penalties, if dependent upon formal ones, implies that: (i) the optimal enforcement regime becomes more lenient, and in some cases the lack of formal punishment is preferred, (ii) the first-best solution becomes unattainable, (iii) liability rates and formal penalty level are no longer perfect deterrence substitutes. In addition, powers of informal penalties provide a rationale for administrative sanctions (informal criticism, reprimands and warnings).
Comparable Estimates of Intergenerational Income Mobility in Italy
Authors: Piraino Patrizio
Published: November 2007

This paper examines the degree and patterns of intergenerational economic mobility in Italy. It uses data from the Bank of Italy's repeated cross-section household survey. Retrospective information on parental economic status may be exploited by applying a two-sample two-stage least squares estimation. I estimate the intergenerational income elasticity for Italy and investigate the main mobility patterns across the distribution. From an overall comparison, the evidence provided in this paper hints that Italy is in the low-mobility group among advanced societies, in the range of values found in the U.S. and the UK. The transmission of economic status appears to be particularly strong at the top of the income distribution. I investigate the role of education in the transmission of economic status in Italy and find evidence that children with the same level of formal education seem to have unequal chances in the labor market depending on family background.
Advertising as a Distortion of Social Learning
Authors: Brekke Kjell Arne , Rege Mari
Published: November 2007

By combining a theory of herding behavior with the phenomenon of availability heuristic, this paper shows that non-informative advertisements can affect people's choices by influencing their perception of product quality. We present a model in which people can learn about product quality by observing the choices of others. Consumers are, however, not able to fully distinguish between the observations of real people and fictitious characters in advertisements. Even if a person is aware of this limitation and updates his beliefs accordingly, it is still rational for him to choose the product he has observed most often. In equilibrium the most observed product is always most likely to be of the highest quality. The analysis has important policy implications.
When Can Manipulations be Avoided in Two-Sided Matching Markets? -- Maximal Domain Results
Authors: Kojima Fuhito
Published: November 2007

In two-sided matching markets, stable mechanisms are vulnerable to various kinds of manipulations. This paper investigates conditions for the student-optimal stable mechanism (SOSM) and the college-optimal stable mechanism (COSM) to be immune to manipulations via capacities and pre-arranged matches. For SOSM, we find that strongly monotone preferences in populations and weakly maximin preferences are the maximal domains of college preferences that guarantee immunity to manipulations via capacities and pre-arranged matches, respectively. In contrast, COSM is susceptible to both manipulations whenever colleges have multiple positions.
Political Parties and Party Systems in Africa: Themes and Research Perspectives
Authors: Carbone Giovanni M.
Published: November 2007

The last decade of the twentieth century was characterised by a resurgence of multipartism in Africa. The return of political parties produced a discontinuity not only in the continent's political life, but also in the study of African politics. A number of new researches were carried out that were largely based on existing theories and concepts in political science. These new works thus contributed to an increased integration of the study of politics south of the Sahara with mainstream political science. The present article provides an overview of the insights and advances that these studies have produced, focusing on the key issues raised by the return of party pluralism in Africa and on the utility of existing models, theories and approaches for its understanding. There is little doubt that recent research efforts have advanced our knowledge of the changing politics of the continent. However, neither the elaboration of theoretical frameworks nor the detail of empirical knowledge has achieved adequate levels of development as yet.
Understanding China's Energy Security
Authors: Constantin Christian
Published: November 2007

This paper seeks to offer a different perspective on China's energy policy and of the role played by security issues in its definition. Hence, it will impart particular attention to conceptions and ideas held by the actors involved in the energy policy decision-making process. It will demonstrate that the different measures that make up Chinese energy policy are the result of a debate among proponents of three frames  a strategic vision, a market approach, and a conception of "scientific development" simultaneously exhibited within China's energy policy community. Each one of these frames sheds light in a unique fashion on the objective conditions confronting Chinese decision-makers by identifying some of them as problematic while leaving others in the shadows, and, at the same time, they offer solutions articulated in their own terms.
Hydrodynamics and axial mixing in a packed gas-liquid column
Authors: Barjaktarovic Branislava , Sovilj Milan , Popovic Svetlana
Published: November 2007

The objective of this study was to investigate the pilot-plant gas absorption packed column hydrodynamics, as well as axial mixing in the system air-water. The pressure drop and the gas phase holdup data were determined in dependence on the flow rates of gas and liquid phases. The influence of superficial velocities of liquid and gas phases on the liquid axial dispersion in a gas-liquid packed bed column (ID 15 cm) consisting of Raschig rings (15x15x2 mm) were investigated. The pressure drop was measured with a U-type manometer, connected to the bottom and the top of the working part of the column. The gas phase holdup data in the air-water two-phase system was calculated as a ratio of the gas phase volume to the total volume of the two-phase system. Axial dispersion in the water phase has been determined by examining of the distribution of residence times of a salt tracer (NaCl) in the packed bed. The tracer was injected in the liquid flow above the packed bed; samples of liquid were simultaneously taken from two sites at 1 m distance along the bed. Salt concentrations in the samples were determined by conductivity measurements. The mean residence time and the axial dispersion number were calculated by the moment method. The axial dispersion increases with an increase of liquid flow velocities and decrease of superficial air velocities.
Phosphogypsum surface characterisation using scanning electron microscopy
Authors: Rajkovic Milos , Toskovic Dragan
Published: November 2007

This paper presents the results of application of Scanning Electron Microscopy (SEM) to examinations of the samples of natural gypsum and phosphogypsum. Phosphogypsum has a well developed crystalline structure, and appear in two polymorphous forms, of rombic and hexagonal shape crystals. Natural gypsum has a poorly crystalline structure. The differences in crystalline structure influence the chemical behavior of these row materials.
Synthesis of some diol DErivatives as potential reagents in steroid chemistry
Authors: Penov-Gasi Katarina , Kuhajda Ksenija , Cvjeticanin Stanko , Djurendic Evgenija , Medic-Mijacevic Ljubica , Pejanovic Vjera , Sakac Marija
Published: November 2007

The multistage syntheses of the p-toluenesulphonyloxy esters (1-benzyloxy-4-p-toluenesulphonyloxybutane (3a) 1-benzyloxy-6-p-toluenesulphonyloxyhexane (3b) and 1-benzyloxy-10-p-toluenesulphonyloxydecane (3c)(, alkyl chlorides (1-benzyloxy-4-chlorobutane (4a), 1-benzyloxy-6-chlorohexane (4b) and 1-benzyloxy-10-chlorodecane (4c)(, as well as alkyl iodides (1-benzyloxy-4-iodobutane (5a), 1-benzyloxy-6-iodohexane (5b) and 1-benzyloxy-10-iododecane (5c)( with the terminal O-benzyl groups starting from 1,4-butanediol (1a), 1,6-hexanediol (1b) and 1,10-decanediol (1c) were carried out. The possibilities of formation and addition of the corresponding Grignard reagent to the C-17 carbonyl group of dehydroepiandrosterone were investigated.
Soy protein modification: A review
Authors: Barac Miroljub , Stanojevic Sladjana , Jovanovic Snezana , Pesic Mirjana
Published: November 2007

Soy protein products such as flour, concentrates and isolates are used in food formulation because of their functionality, nutritional value and low cost. To obtain their optimal nutritive and functional properties as well as desirable flavor different treatments are used. Soybean proteins can be modified by physical, chemical and enzymatic treatments. Different thermal treatments are most commonly used, while the most appropriate way of modifying soy proteins from the standpoint of safety is their limited proteolysis. These treatments cause physical and chemical changes that affect their functional properties. This review discusses three principal methods used for modification of soy protein products, their effects on dominant soy protein properties and some biologically active compounds.
Influence of additive from sugar beet on white bread quality
Authors: Filipovic Nada , Gyura Julianna , Filipovic Jelena
Published: November 2007

The additive of acceptable sensory, physical and chemical and microbiological characteristics was made from cossettes. Great water binding capacity related to microcrystals of cellulose qualifies this additive as a desired one in bread making process. Bread was baked in the laboratory and patent flour was used. The additive with particles smaller than 95 (m was supplemented in the quantities of 2, 5 and 10%. The data related to the influence of the quantity of additive on white bread quality point that parallel to increasing the amount of the additive in the dough, yield of dough and bread were also increased. Negative effects are detected as volume depression and inferior bread crumb quality and altered crumb color. The decrease in bread quality is small if 2% of additive was applied, but significant with 5 and 10%. The bread freshness was highly graded 48 hours after baking due to the ability of the additive to retain water. On the whole, bread of superior quality supplemented by 5 and 10% of the additive from sugar beet fiber can be easily made by fortifying flour with gluten and by adding appropriate dough conditioner.
Investigation of activated Al-pillared clay efficiency in vegetable oil purification
Authors: Lomic Gizela , Kis Erne , Dimic Etelka , Romanic Ranko
Published: November 2007

This paper represents a contribution to the applicability of natural clays and their derivates as adsorbents in the process of purification of vegetable oil. Investigation of textural properties of raw and purified clay samples reveals that during acid activation and Al-pillaring, BET and micropore surface area increases significantly. However, bleaching capacity of clay and its derivates is not determined by using sample surface area, but rather sample total pore volume. Surface area, especially micropore surface area contributes to removal of smaller molecules. This was confirmed by successful elimination of moisture and volatile materials by samples with an appropriate micropore structure. Used samples of clay and its derivates do not significantly influence acid and peroxide values of raw sunflower oil during its treatment.
Application of scanning electron microscopy in catalysis
Authors: Lomic Gizela , Kis Erne , Boskovic Goran , Marinkovic-Neducin Radmila
Published: November 2007

A short survey of various information obtained by scanning electron microscopy (SEM) in the investigation of heterogeneous catalysts and nano-structured materials have been presented. The capabilities of SEM analysis and its application in testing catalysts in different fields of heterogeneous catalysis are illustrated. The results encompass the proper way of catalyst preparation, the mechanism of catalyst active sites formation catalysts changes and catalyst degradation during their application in different chemical processes. Presented SEM pictures have been taken on a SEM JOEL ISM 35 over 25 years of studies in the field of heterogeneous catalysis.
Kinetics of photocatalytic removal of 2-amino-5-chloropyridine from water
Authors: Abramovic Biljana , Anderluh Vesna , Topalov Andjelka , Gaal Ferenc
Published: November 2007

Titanium dioxide sensitized photocatalytic degradation of a pyridine pesticide analogue, 2-amino-5-chloropyridine, was investigated by monitoring the pyridine moiety degradation, as well as by monitoring the chloride generated in the process. Effect of the initial substrate concentration on the rate of its degradation is reported. Here we show that the kinetics of both reactions are of the zero-order in the entire investigated concentration range. The Langmuir-Hinshelwood kinetic model successfully described the influence of the initial substrate concentration on the rate of the pyridine moiety degradation. It was found that dechlorination of the substrate takes place by direct photolysis. The differences in the kinetics of pyridine moiety degradation and dechlorination were explained on the basis of the electrostatic potential for the investigated compound.
Determination of sensitivity limit in quantative analysis of polycyclic aromatic hydrocarbons by Gc-ms
Authors: Marjanovic Nikola , Kravic Snezana , Suturovic Zvonimir , Svarc-Gajic Jaroslava
Published: November 2007

The limit of detection (LOD) and the limit of quantitation (LOQ) for 16 individual PAHs from the Environmental Protection Agency (EPA) list (naphthalene, acenaphthylene, acenaphtene, fluorene, phenanthrene antrachene, fluoranthene, pyrene, benzo(a)anthracene, chrysene benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h) anthracene, benzo(g,h,i)perylene and indeno(1,2,3-cd)pyrene) were determined by Gas Chromatography ? Mass Spectrometry (GC-MS). Determination was performed by SCAN (digital linear scanning) and SIM (selected ion monitoring) techniques preceded by the optimization of the experimental factors. The limit of detection obtained by the SCAN technique was in the range of 0.179 ? 15.236 ng, and the quantitation limit in the range of 1.017 ? 50.788 ng. SIM technique enabled LOD and LOQ in the range of 0.036 ? 13.886 pg and 0.119 ? 46.287 pg respectively.
Immobilization of glucoamylase on macroporous spheres
Authors: Milosavic Nenad , Prodanovic Radivoje , Jovanovic Slobodan , Vujcic Zoran
Published: November 2007

Glucoamylase was covalently immobilized through the spacer-arm of the poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) spheres by using a glutaraldehyde as a coupling agent. The influence of the enzyme load applied to the support on immobilization, yield and specific activity, has been determined. Obtained specific activity was 700 U/g with immobilization yield of 35 %. The Km value for immobilized glucoamylase was 1.28 % (w/v), pH and temperature optimum were 4.5 and 70?C, respectively. The conversion of 20 % (w/w) starch hydrolysate achieved with the immobilized glucoamylase was 97 % after 5 hours.
Characterization of alkali-modified soy protein concentrate
Authors: Barac Miroljub , Stanojevic Sladjana , Jovanovic Snezana
Published: November 2007

To study the influence of the preparation mode, including mild alkali modification, of soy protein concentrate on soluble protein content and composition, some of its nutritive and functional properties were investigated. Soy protein concentrate prepared by aqueous alcohol leaching was modified in mild alkaline solutions (pH 8.0) at 40, 50 and 60? C for 60 minutes and compared with two principal types of commercial soy protein concentrate. Soluble protein content, composition and properties of soy protein concentrate, as well as their potential use are essentially determined by the preparation mode. Limited mild alkali hydrolysis increased protein solubility by 40-71%, while emulsion stability was increased by 18-56%. Major storage soybean proteins exhibited different stability to alcohol denaturation and mild alkali modification. The most susceptible were acidic -A3 - and -A5- subunits of glycinin.
Fungal growth during malting of barley
Authors: Kocic-Tanackov Suncica , Skrinjar Marija , Grujic Olgica , Pejin Jelena
Published: November 2007

Fungi were isolated and identified in two samples of winter two-row barley (SSK3 and SSK6) harvested in 2003, Kragujevac location, during micromalting. Fungi were isolated and identified in barley before the micromalting, after the 1st, 2nd and 3rd day of steeping, the first day and after the germination after kilning and after malt degermination. The total fungi count was followed in both barley samples, during the mentioned phases. The total count of fungi was also determined in the steeping water, and the isolation and identification was performed after the steeping process. Change of the total count of fungi during barley micromalting was exponentional. During barley micromalting nine fungi genera were isolated: Phoma, Alternaria, Fusarium aspergillus, Cladosporium, Geotrichum, Scopulariopsis, Aureobasidium and Mucor. The most frequent genera were: Phoma, Alternaria and Fusarium. In water for steeping, five genera were identified: Geotrichum, Fusarium, Phoma Cladosporium and Mucor. The most frequent genera was Phoma.