bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling of the Mass Transfer Effect in Biphasic Enzyme Membrane Reactor for Hydrolysis of Olive Oil
Authors: Pugazhenthi G , Kumar Anil
Published: August 2008

This article presents a model to explain the mass transfer phenomenon of the ions (OH-, Na+ and RCOO-) formed during the hydrolysis reaction on the aqueous side of the reaction sites in the biphasic enzyme membrane reactor (EMR) using lipase immobilized on modified poly (methyl methacrylate-ethylene glycol dimethacrylate) (PMMA-EGDM) clay composite membrane. Our model divides the aqueous side of the system into two regions, an unstirred film (aqueous side) adjacent to the pore end (region I) and charged capillaries of the membrane (region II). The process involves transport of Na+, OH- and RCOO- ions in region I whereas the film is considered as an electro-neutral region. Space charge model (consisting of Nernst-Planck equation for ion transport and nonlinear Poisson-Boltzmann (PB) equation for charge distribution) is used to describe transport of ions inside charged capillaries (pores) in region II. The solution of the nonlinear PB equation is computationally intensive and to overcome this difficulty, a series solution of the PB equation for the charge distribution inside the capillaries is developed. The suggested solution is used to determine the rate of formation of oleic acid using the information on pore size of the membrane (determined from molecular weight cut-off experiment) and diffusivity data from the literature. The result shows that the concentration of RCOO- ions at the boundary of region I of the aqueous phase increases with increasing the duration of reaction. The pore wall charge determined using the model is found to be in the range of 0.715-0.735 mV.
Fermentative Production, Purification and Characterization of Nisin
Authors: Gujarathi Swapnali S , Bankar Sandip B. , Ananthanarayan Laxmi A.
Published: August 2008

Bacteriocins are bactericidal or bacteriostatic in action and active against closely related species. Nisin is the bacteriocin produced by the lactic acid bacteria (LAB). Nisin is a small (3353 Da), cationic, hydrophobic, and 34-amino acid peptide. It is used in products such as pasteurized processed cheese, salad dressing, and liquid whole eggs to inhibit the growth of Gram-positive microorganisms including Listeria monocytogenes. The objective of the present work was to study production, purification and characterization of nisin. The production of nisin was carried out using Lactococcus lactis subsp lactis MTCC 440 by one-factor-at-a-time method and statistical design (Orthogonal array). Purification was carried out using ammonium sulphate precipitation followed by hydrophobic interaction and gel chromatography. Characterization was done for pH and temperature stability. The activity of nisin after one factor at a time optimization was found to be 5120 AU/ml. The activity of the nisin increased to 6800 AU/ml after optimization by Orthogonal Array design. Ammonium sulphate precipitation gives good yield of nisin with 60 to 80% saturation with 2.52 fold purity. The overall purification by hydrophobic interaction and gel filtration chromatography was 10.87 fold with 50.84% yield and 8.8 fold with 49.65% yield as compared to crude broth respectively.
Improved Process of Cassava Processing into ``Attiéké'', a Traditional Food Product of Côte D'Ivoire
Authors: Toka Marie Djégba , Djéni Théodore N'Dédé , Dje Marcellin Koffi
Published: August 2008

In Côte dIvoire, Cassava roots are mainly processed into attiéké, a kind of fermented cassava semolina, dried and steamed. This food, widely consumed, is produced by women according to a traditional technology requiring several hard operations. When the dough is not immediately processed into attiéké, it rots. Therefore, an improved process involving washing and storage of the fermented dough in a closed bucket was tested. This process lead to a stabilized dough which could be preserved for at least four weeks. The cyanide content in this dough represented 25% of the traditional ones (39.50 ± 0.8 mg/kg). Both dough were safe of Enterobacteria. They mainly contained lactic acid bacteria (1 to 1.7×108 cfu/g) which grew during the stabilized dough storage. Attiéké from this dough was similar to the traditional attiéké. As stabilizing the fermented dough, the new process should encourage the growth of attiéké production efficiency, the producer incomes and cassava production increase.
Effect of Osmotic Pre-Treatment on the Air-Drying Behavior and Quality of Plum Tomato Pieces
Authors: Brooks Marianne S , Ghaly Abdel E , Abou El-Hana Nabiha H
Published: August 2008

The air-drying behavior and quality of plum tomato pieces after pre-treatment with different osmotic solutions was investigated. Four pre-treatment solutions (comprised of salt, sugar and/or calcium lactate), three sample geometries (halves, quarters and eighths) and two air-drying temperatures (55 and 65°C) were studied. During osmotic pre-treatment, the moisture loss of the tomato pieces decreased with osmotic pressure. The proportion of skin to cut surface area was found to be important for osmotic moisture loss. As the percentage of cut surface area decreased (59.6%, 47.6% and 25.3% for the eighths, quarters and halves, respectively) and the percentage of skin on the sample increased, the percentage osmotic moisture loss also decreased. At an air-drying temperature of 55°C, the critical moisture content for storage (15%, wet basis) for the pre-treated halves, quarters and eighths was reached after 25-27, 15-18 and 9-12 hours, respectively. At 65°C, the critical moisture content was reached after 16-19, 9-13 and 6-8 hours, respectively. In both cases, the osmotic pre-treatment reduced the critical drying time. The reduction in moisture ratio over time was described by an exponential model (R2 values ? 0.92). The specific drying rate increased with osmotic pre-treatment and was more affected by air-drying temperature than the type of osmotic solution, while the geometry of the samples had no significant effect. Air-dried samples with osmotic pre-treatment were closer to the color of fresh tomato than samples without pre-treatment.
Pre-Design of a Continuous Intensified Reactor Based on Pure Thermo-Chemical Optimisation
Authors: Di Miceli Raimondi Nathalie , Elgue Sébastien , Prat Laurent , Cognet Patrick , Cabassud Michel
Published: August 2008

A continuous intensified reactor requires precise information to adapt the design to the reaction to be implemented. In this article we present a two step approach to pre-designing such devices. The first step consists of the optimisation of the operating conditions based only on stoichio-chemical schemes and kinetic laws. This is carried out by adjusting the temperature profile and feeding rate strategy in a batch or pseudo-batch operation. The second step departs from the ideal thermo-kinetic path by taking into account heat removal and reagent injection. A simulator is used to evaluate the impact of these constraints on the selectivity and productivity. The approach is applied to the linear alkylbenzene sulfonation which characteristics present most of the challenges encountered in the intensification. Final results give a pre-design in terms of reactor characteristics (size, injections positions) and operating conditions.
A Quantitative Structure-Activity Relationship Model
Authors: Zahouily Mohamed , Lazar Mohamed , Bnoumarzouk Marouan , Mouhibi Rokaya , Nohair Mohamed , Bahlaoui M. Abdellah
Published: August 2008

Structure-activity relationships were studied for a series of 46 2.6-dimethyl-3.5-dicabomethoxy-4-phenyl-1.4-dihydropyridine derivatives by means of multiple linear regression (MLR) and artificial neural network (ANN) techniques. The values of log (1/EC50), which represents the 50% effective concentration for blocking the Ca2+ channel of the studied compounds were correlated with the descriptors encoding the chemical structures. Using the pertinent descriptors revealed by the regression analysis, a correlation coefficient of 0.99 (s = 0.23) for the training set (n = 46) was obtained for the ANN using the Levenberg-Marquardt algorithm with a 3-10-1 configuration. The results obtained from this study indicate that the activity of 2.6-dimethyl-3.5-dicabomethoxy-4-phenyl-1.4-dihydropyridine derivatives is strongly dependent on molar refractivity (MR), electronic factors (especially on the connectivity indices (IC0)) and hydrogen-bond donor's (HBD) of the molecule. Comparison of the descriptor's contribution obtained with MLR and ANN models indicates the presence of non-linearity in the data and the interaction effect between them since the efficiency of these descriptors was increased by the ANN model.On the other hand, we have used a new, robust structure-activity mapping technique, a Bayesian-regularized neural network, to develop a quantitative structure-activity relationship (QSAR) model, and the ability of the model was tested by using the cross validation technique. The results show that the method is robust and reliable and gives good results. Comparisons of Bayesian neural net models with those derived by classical MLR model analysis showed its superiority in generalization.
Modeling and Simulation of Aluminum Nanoparticle Synthesis by the Evaporation-Condensation Process Using the Nodal Method
Authors: Setyawan Heru , Yuwana Minta
Published: August 2008

In this work, a model for particle formation and growth is used to simulate the aluminum particle synthesis by an evaporation-condensation process. The effect of commonly employed process parameters (vaporization temperature, cooling rate, system pressure) is investigated. The model to be solved is the general dynamic equation (GDE) that accounts for particle nucleation, condensation and coagulation at non-isothermal conditions. The GDE was solved using the nodal method. The methodology approximates the particle size distribution to a few nodes by introducing size-splitting operators. The simulation results show that particle formation and growth take place in a short temperature range. The coagulation increases the particle size while maintaining the number concentration. On the other hand, the surface condensation tends to shift the particles size distribution towards a larger size. It was shown that production of nanoparticles with a more uniform size distribution and smaller particles are favored using low pressure and low vaporization temperature. The particle size distribution is nearly influenced by the cooling rate in the range study here.
Too Few Cooks Spoil the Broth: Division of Labor and Directed Production
Authors: Ratto Marisa , Schnedler Wendelin
Published: August 2008

How can a manager influence workers' activity, while knowing little about it? This paper examines a situation where production requires several tasks, and the manager wants to direct production to achieve a preferred allocation of effort across tasks. However, the effort that is required for each task cannot be observed, and the production result is the only indicator of worker activity. This paper illustrates that in this situation, the manager cannot implement the preferred allocation with a single worker. On the other hand, the manager is able to implement the preferred allocation by inducing a game among several workers. Gains to workers from collusion may be eliminated by an ability-dependent, but potentially inefficient, task assignment. These findings provide a new explanation for the division of labor, and bureaucratic features such as ``over"-specialization and ``wrong" task allocation.
The Internet and the Market for Daily Newspapers
Authors: George Lisa M
Published: August 2008

A growing literature documents that electronic media draw consumers from traditional media markets. Less work examines how the internet has altered the audience for traditional media. Using zipcode-level newspaper circulation and market-level internet penetration, this paper provides evidence that the internet differentially attracts younger, educated, urban individuals away from daily newspapers. Greater internet penetration is associated with higher newspaper circulation among blacks and Hispanics, who thus far are less likely to connect. Evidence suggests the spread of the internet is also associated with changes in newspaper coverage, with greater emphasis on minorities, education, crime and investigative reporting.
The Employment Effects of Mergers in a Declining Industry: The Case of South African Gold Mining
Authors: Behar Alberto , Hodge James
Published: August 2008

With data from the South African gold mining industry, we find evidence consistent with theories that mergers and acquisitions allow for the shedding of excess labor. Mergers are arguably exogenous in our sample, while an industry in decline can provide a good setting for testing the theories. The data clearly portray rises in real wages and falling employment after the end of apartheid. We find evidence of a significant negative effect of mergers/acquisitions on employment. The magnitude is similar to the effect in Continental Europe and larger than the effect in the United States. This supports the view that negative employment impacts are more likely in rigid labor markets.
Environmental Policy and Uncertain Arrival of Future Abatement Technology
Authors: von Döllen Andreas , Requate Till
Published: August 2008

We study long-term incentives for regulated polluting firms to invest in advanced abatement technologies when some new technology is available but even better technology is expected for the future. Firms can invest only once. We find that, depending on the cost of adoption, all possible investment patterns can occur in social optimum. Further, a regulator who anticipates the arrival of the new technology can decentralize the socially optimal allocations by announcing either a Pigouvian tax or tradable permits and by setting ex post optimal policy levels after firms have invested.
Discrimination as a Competitive Device: The Case of Local Television News
Authors: Myers Caitlin Knowles
Published: August 2008

Previous studies of discrimination have explored the role that customer prejudice may play in lowering the marginal revenue product of minority employees and, hence, lowering their equilibrium wages. I observe that variation in these types of customer preferences creates an incentive for firms to respond strategically by engaging in product differentiation via the characteristics of their employees. Analysis of data collected for local television news stations supports the predictions of this model of "competitive discrimination." There is a negative correlation between the racial, gender, and age compositions of competing news stations. Moreover, Nielsen ratings for station broadcasts indicate that viewers of stations with more black employees are less discriminatory than viewers of stations with fewer blacks. A similar result is found when examining the age and gender composition of employees.
Predicting Resource Policy Outcomes via Meta-Regression: Data Space, Model Space, and the Quest for 'Optimal Scope'
Authors: Moeltner Klaus , Rosenberger Randall S
Published: August 2008

Resource-managing agencies are increasingly relying on secondary data to predict economic benefits for planned policy interventions. This `transfer of benefits' is often based on a quantitative synthesis of aggregate results for similar past interventions via Meta-Regression Models. However, this approach is generally plagued by the paucity of available studies and related small sample problems. A broadening of scope of the Meta-Regression Model by adding data from ``related, yet different" contexts or activities may circumvent these issues, but may not necessarily enhance the efficiency of transfer functions if the different contexts do not share policy-relevant parameters. We illustrate how different combinations of contexts can be interpreted as `data spaces' which can then be explored for the most promising transfer function using Bayesian Model Search techniques. Our results indicate that model-averaged benefit predictions for scope-augmented data spaces can be more robust and efficient than those flowing from the baseline context and data.
Young children's detection and decoding of ironic intonation
Authors: Rattray Catherine , Tolmie Andrew
Published: August 2008

Young children's detection and decoding of ironic intonation

Two studies examined 3- and 4-year-olds' ability to follow the mental ‘sub-text’ of conversations employing ironic intonation. In Study 1, children were asked what a confederate thought was inside a tin, following an exchange in which she saw (joke conditions) or did not see (lie conditions) the contents (a stone) and heard these referred to in neutral or ironic tone as a cake. Study 2 repeated the joke conditions, with the confederate touching the stone. Amongst 4-year-olds, intonation was found to trigger complex assessment of the information available to the confederate, whilst 3-year-olds appeared confused. The data suggest that ability to track the belief implications of conversations is underpinned by substantial improvements in working memory between 3 and 4 years.
Collaboration in Public Health: A New Global Imperative
Authors: King Lonnie J.
Published: August 2008

This commentary first appeared in Public Health Reports 123:264, 2008.
Joint Degree Programs in Public Health
Authors: Hueston William D.
Published: August 2008

Public health and veterinary medicine share a focus on population health and primary prevention, along with a commitment to preparedness, response, and recovery in the event of disease outbreaks. Public-health and veterinary professional degree programs share commonalities in their educational accreditation requirements related to epidemiology and public-health practice. The initiation of a number of joint professional degree programs over the last five years, including the joint Doctor of Veterinary Medicine and Master of Public Health (DVM/MPH), represents an exciting development for inter-professional education for veterinarians interested in public health. Various models for joint DVM/MPH educational programs are discussed, including pre-veterinary public-health credentialing, integrated programs, and post-DVM executive programs. Collaborations between colleges of veterinary medicine and schools of public health show great promise in both educational and research innovation.
The Dual DVM/MPH Degree at the University of Wisconsin—Madison: A Uniquely Interdisciplinary Collaboration
Authors: Olsen Christopher W. , Remington Patrick L.
Published: August 2008

The University of Wisconsin—Madison (UWM) launched a new Master of Public Health (MPH) degree program in 2005. This 42-credit MPH degree consists of 18 core and 14 elective course credits, two seminar credits, and eight field project/culminating experience credits. Unique strengths of the program include its strongly interdisciplinary philosophy, encompassing both health science (human medicine, veterinary medicine, pharmacy, nursing) and social science units on campus, and its emphasis on service learning through instructional and field project ties to the public-health community of the state and beyond. To date, the program has admitted 87 students, including full-time students as well as part-time students who continue to work in the health care and/or public-health sectors. The program is currently proceeding with the process for accreditation through the Council for Education in Public Health. In 2007, a formal dual DVM/MPH program was approved to allow students to integrate DVM and MPH training and complete both degrees in a total of five years. Nine MPH students over the first three years of admissions have been individuals affiliated with veterinary medicine (five DVM students and four post-graduate veterinarians).
Veterinary Public Health in a Problem-Based Learning Curriculum at the Western University of Health Sciences
Authors: Schmidt Peggy L. , Trevejo Rosalie T. , Tkalcic Suzana
Published: August 2008

As detailed in the Association of Schools of Public Health / Association of American Veterinary Medical Colleges 2007 Joint Symposium on Veterinary Public Health, veterinary public health (VPH) can no longer be viewed as a unique sub-specialty of veterinary medicine. Rather, its practice pervades nearly every aspect of the veterinary profession, regardless of whether the practitioner is engaged in small-animal, large-animal, research, corporate, or military practice. In congruence with the practice of VPH, the teaching of VPH should also pervade nearly every aspect of veterinary education. Accordingly, at Western University of Health Sciences, College of Veterinary Medicine (WU-CVM), public health is not simply taught as an individual course but, rather, is interwoven into almost every aspect of the curriculum, continually emphasizing the relevance of this discipline to the practice of veterinary medicine. This article outlines the teaching philosophy of WU-CVM, provides an overview of the curriculum, and describes the integral nature of public health throughout all four years of the educational program.
Public-Health Instruction Necessary to Supplement the Veterinary Professional Curriculum: The DVM/MPH Coordinated-Degree Program at Auburn University
Authors: Wenzel James G.W. , Nusbaum Kenneth E. , Wright James C. , Hall Dugald C.A.
Published: August 2008

To meet long-term needs, many veterinary colleges and schools are participating in dual-degree DVM/MPH programs. Auburn University's College of Veterinary Medicine and the School of Public Health at the University of Alabama at Birmingham have developed a coordinated-degree curriculum in which the DVM and the MPH are not necessarily awarded simultaneously. Other opportunities at Auburn include Public Health Careers Day, trips to the Centers for Disease Control and Prevention, several elective courses related to veterinary epidemiology, and online access to the Emerging and Exotic Diseases of Animals course available from the Veterinary Information Network. We have been able to increase our students’ exposure to the role of the veterinarian in public health and to develop a program to augment their training in public practice.
The Need for Public-Health Veterinarians as Seen by Future Employers
Authors: Maccabe Andrew T. , Matchett Karin E. , Hueston William D.
Published: August 2008

Future employers of veterinarians working in public health see a fast-growing demand. Emerging zoonotic diseases, bio-security threats, and food-safety problems all require the expertise of veterinarians with a focus on complex, global problems that span both human and animal health. The Public Health Task Force of the Association of American Veterinary Medical Colleges convened a group of stakeholders representing various branches of the US federal government, state and local governments, and professional societies to discuss their needs for public-health veterinarians. This article discusses those needs, the broader societal needs that require veterinarians with public-health expertise, and the implications of these for educational programs to train DVMs in public-health issues.
Relating Cost to Condition in Routine Highway Maintenance
Authors: Juni Emil , Adams Teresa M. , Sokolowski David
Published: August 2008

When transportation agencies prepare a design for new highway construction or major improvements to existing highways, the life-cycle, agency, and user costs are considered in project design decisions. However, after highway projects are completed, maintenance budgets often do not keep pace with maintenance needs since they are rarely adjusted to accommodate the routine maintenance of new lane miles. Instead, maintenance budgets per lane mile remain relatively constant, regardless of increase in the number of vehicle miles traveled per highway mile. Thus, disparity increases between maintenance budgets and maintenance requirements, leading to difficult choices for maintenance priorities. Concerns about safety and mobility tend to trump preservation of capital investment. A study is presented of the relationship between maintenance cost and condition. With use of regression tree analysis, the study identified physical, environmental, operational, and socioeconomic parameters that influence maintenance costs for asphalt and concrete pavements, shoulders, litter pickup, vegetation control, and ditches. As a result, valid model equations will show just what kind of effect a certain investment has on the level of service. Other models will show how much investment is needed to get to a certain level of service. These models will provide information to maintenance managers about the trade-offs they will get based on the relationship of cost and maintenance, so they can make the best decision in allocating available funds.
Sampling Procedure for Performance-Based Road Maintenance Evaluations
Authors: de la Garza Jesus M. , Piñero Juan C. , Ozbek Mehmet E.
Published: August 2008

Maintaining the road infrastructure at a high level of condition with generally limited amounts of available funding is a challenge for many transportation agencies. To address this challenge, many road administrators worldwide have implemented performance-based maintenance contracts. In performance-based maintenance contracts, road administrators define performance measures (e.g., performance-based specifications) that specify the minimum condition at which the asset items are to be maintained. To ensure that contractors maintain the asset items according to these measures, road administrators must design and implement a comprehensive and reliable performance monitoring process. One of the most important areas within the performance monitoring process is inspection conducted in the field. Defining a procedure that guarantees the success of field inspections is a challenge. When defining such a procedure, road administrators must consider budget and time limitations, among others. Since performance-based road maintenance contracts are relatively new, the availability of guidelines for such issues (with focus on performance-based contracts) is limited. That need is addressed by presentation of a three-stage and seven-step statistical sampling procedure developed to ensure that findings from field inspections will be reliable and representative with high confidence of the actual condition of asset items in the entire population. Also presented are three alternative approaches for sampling for the cases in which sampling needs to be performed not just once but multiple times over the duration of a performance-based road maintenance contract.
Shaping the Future of the Workforce for Intelligent Transportation Systems
Authors: Hinkeldein Daniel Christoph , Pecena Yvonne , Jörn Lisa
Published: August 2008

Intelligent transportation systems (ITSs) can operate successfully only if selection and training of personnel are carried out in a systematic, theoretically sound way. Given the increasing responsibility of operators, a scientific analysis to develop requirements and specifications for training and selection is necessary. Despite the increasing deployment of ITS in industrialized countries, no systematic, empirically supported requirements analysis—including ability level, as well as task level—has yet been done for traffic operators in traffic management centers (TMCs), tunnel operation centers (TOCs), and urban traffic control centers (UTCs). A general requirement profile was established—including knowledge, skills, and abilities—for operators in all three different center types. Differences for traffic operations in TMCs, TOCs, and UTCs were highlighted. Moreover, consequences were drawn for selection processes for potential operations employees and, an overview was provided of tasks needing to be taught specifically. The methods and results shown are particularly helpful for researchers and practitioners in the operational field of ITS.
Bridge Inspection and Condition Assessment in Europe
Authors: Helmerich Rosemarie , Niederleithinger Ernst , Algernon Daniel , Streicher Doreen , Wiggenhauser Herbert
Published: August 2008

The European infrastructure asset has developed historically and is characterized by nation-specific construction processes. Inspection, condition assessment, and maintenance procedures differ from country to country. Because of historical and political circumstances, national infrastructure assets are maintained at different levels, too. Since the budget for maintaining the bridge infrastructure less and less meets the demands of a growing bridge stock, bridge inspection, maintenance, and life-cycle considerations gain higher importance. The need exists to develop effective diagnosis tools for early detection of construction faults, defects, and deterioration processes during inspection, to keep the bridge infrastructure at an acceptable level, from structural safety and economic viewpoints. An overview on the latest research projects and integrated bridge management systems in Europe is given. The potentials of nondestructive testing (NDT) are presented, with special focus on technical advances of NDT applications to reinforced concrete (RC) and posttensioned concrete bridges. Although NDT is not regularly integrated in these processes, the application brings valuable information on the current condition of the inner structure in called-in special inspections. NDT-automation and the application of imaging echo methods, combined with advanced data processing, produce a surprising level of information about the inner structure of massive RC slabs up to a depth of about 60 cm. Detected inhomogeneity and scatterers of acoustic or electromagnetic waves can be visualized in vertical or horizontal slices through the structure or animations. The fusion of different three-dimensional data sets of processed data improves the interpretability and accuracy of the results.
Ground-Penetrating Radar, Chain Drag, and Ground Truth
Authors: Yehia Sherif , Abudayyeh Osama , Abdel-Qader Ikhlas , Zalt Ammar
Published: August 2008

Determining the degree of degradation of a bridge can be one of the most difficult problems that infrastructure inspectors face. While traditional bridge inspection methods such as visual and chain drag will always play a role in bridge condition assessment, more sophisticated and accurate techniques such as ground-penetrating radar (GPR) are gradually gaining acceptance by departments of transportation. GPR is a nondestructive evaluation method that can be used to assess the integrity of roads, pavements, bridges, and buildings. It uses high-frequency electromagnetic waves at the microwave or radio frequency range to examine the subsurface condition. This technique is used to detect features, such as cracks, voids, and delamination. An evaluation was made of GPR effectiveness in condition assessment compared with effectiveness of chain drag and ground truth method (cores) of two concrete bridge decks. Results show that the GPR method has potential as a practical and economically viable means for bridge assessment.
Assessment of Electrical Injection of Corrosion Inhibitor for Corrosion Protection of Reinforced Concrete
Authors: Pan Tongyan , Nguyen Tuan Anh , Shi Xianming
Published: August 2008

Chloride ingress is the major cause of rebar corrosion that deteriorates reinforced concrete structures in chloride-laden environments. A recently emerged electrochemical technique—the electrical injection of corrosion inhibitor (EICI)—shows its potential in protecting a rebar from chloride attack by driving corrosion inhibitors to the rebar surface under an externally applied electric field. Potential applicability of EICI as a routine electrochemical treatment for corrosion protection is assessed. A comprehensive evaluation of currently available organic cation-based inhibitors was conducted on the basis of the measured corrosion inhibition performance and diffusion coefficient of each inhibitor. With the use of a two-dimensional finite element model, the concentration evolution of the selected inhibitors and chloride were predicted on the rebar surface and in concrete, and the applicability of EICI was examined thereafter. Important aspects of EICI were studied including mainly inhibitor type, magnitude of applied current density, and treatment time. Recommendations about EICI practice were made accordingly.
Survey of Cathodic Protection Systems on Virginia Bridges
Authors: Brown Michael C. , Sharp Stephen R.
Published: August 2008

A study investigated the status of cathodic protection systems that had been deployed on Virginia highway bridge structures over the past 24 years. A variety of system types had been used on structures located across the state. The general design, current status, and notes about observed performance of each system are presented. A summary of general observations about the state of cathodic protection technology in Virginia is provided. From visual observations, review of available condition reports, and discussions with system design and maintenance personnel, it was concluded that cathodic protection was successfully deployed in many, but not all, of the attempted applications in Virginia. However, a comprehensive and unified strategy for monitoring and maintenance of Virginia's cathodic protection systems is needed.
Understanding the Effects of Aggregate and Emulsion Application Rates on Performance of Asphalt Surface Treatments
Authors: Lee Ju Sang , Kim Y. Richard
Published: August 2008

Presented are the effects of aggregate and emulsion application rates on the performance of asphalt surface treatments (ASTs), as evaluated by the third-scale Model Mobile Loading Simulator (MMLS3) and digital image processing. Performance characteristics evaluated in this study include aggregate loss and bleeding. Lightweight aggregate and granite aggregate with different gradations were used with CRS-2 emulsion to design the various combinations of aggregate and emulsion application rates. The MMLS3 test protocol was applied to these AST specimens, and performance measurements were analyzed as a function of the application rates. Results demonstrated that the new AST performance test method introduced in this study was an excellent means of evaluating AST performance. It was found that the major factor affecting AST performance was aggregate gradation. Also, a method was developed to determine the optimum aggregate and emulsion application rates from the MMLS3 test results. The optimum rates determined from this method were confirmed by a blind test performed by bituminous supervisors and road maintenance unit engineers at the North Carolina Department of Transportation. Finally, results from this study were used to study the voids concept, which serves as the foundation for AST mix design. It was concluded that the reference voids (the compacted voids resulting from MMLS3 trafficking) depend on the voids in the loose aggregate that are, in turn, affected by the aggregate gradation type.
Safety Effect of Preventive Maintenance
Authors: Erwin Tara , Tighe Susan L.
Published: August 2008

Various North American transportation agencies have implemented several preventive maintenance techniques to improve pavement performance and safety. The York Region, located northeast of Toronto, Ontario, Canada, has been resurfacing and remedying pavements with microsurfacing treatments to improve the pavement surface conditions, but without a good understanding of how the treatment affects road safety. With data made accessible by the region, a before-and-after study was done, with the goal of gaining an understanding of how microsurfacing and resurfacing treatments affect road safety. The study concludes that microsurfacing and resurfacing can have a positive safety effect, with crash reduction factors as high as 54%. However, those activities are sensitive to the influence of treatment year data (which may be an anomaly period) and average annual daily traffic per lane. Generally, the findings illustrate that microsurfacing has a positive safety effect on locations susceptible to a number of conditions: regular occurrence of wet or slick (not dry) road surface conditions, a trend toward severe crashes, frequent intersection-related crashes, and a high occurrence of rear-end crashes. Findings of this study have opened the door to additional research; integration of safety under the pavement umbrella seems so logical and yet has barely been explored. For now, the crash reduction factors derived from the study can be applied by the region of York and by other jurisdictions to make more sound decisions at the network level when selecting pavement maintenance treatments.
Effect of Bituminous Material Rheology on Adhesion
Authors: Al-Qadi Imad L. , Fini Eli H. , Masson J.-F. , McGhee Kevin M.
Published: August 2008

Bituminous materials are used in many civil engineering applications in which adhesion to a substrate is essential for good performance. Yet it is not possible to predict the adhesion of these materials. The particular case of bituminous crack sealants is of interest; the effect of sealant viscosity, aging, test temperature, and loading rates was investigated by means of a blister test. This test provided the bonding characteristics to a model aggregate in relation to interfacial fracture energy (IFE). From testing of several sealants, it was found that pouring viscosity affects adhesion and that higher viscosities help to attain higher IFEs. Temperature was found to play a key role on bonding characteristics and failure mechanism because it affected the viscoelastic properties of the sealant. The glass transition temperature (Tg) was found to have a governing role on bonding characteristics. At temperatures above Tg, bond strength was found to be affected by sealant flow such that failure was flow related; that is, cohesive failure prevailed. At temperatures below the Tg, at which sealants were stiff and bulk deformation was low, stress was directed toward the interface so that failure tended to be adhesive. In taking into account temperature and test rates, an IFE master curve was obtained for a sealant. Such a curve may be used in predicting and comparing sealant IFE.
Nonsupercritical synthesis of microporous gels
Authors: Pollini M. , Sannino A. , Maffezzoli A. , Licciulli A. , Nicolais L.
Published: August 2008

In this work, the development of microporous gels using a novel degradation process not involving supercritical fluids is proposed. Photosensitive organic–inorganic hybrid sols in an alcoholic solution based on TEOS and an organic modified alcoxysilane were gelled by photopolymerization, and then dried at ambient pressure before sintering at 550°C. The result was a microporous gel with porosity higher than 90%. Chemical, physical, thermal, and mechanical characterizations were carried out on the microporous gel obtained by the nonsupercritical drying procedure. These results demonstrated the physical properties comparable with those of aerogels obtained by supercritical drying can be obtained. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and morphology of carboxylated polyether‐block‐polydimethylsiloxane and the supermolecule self‐assembled from it
Authors: An Qiufeng , Yang Gang , Wang Qianjin , Huang Liangxian
Published: August 2008

In this research, hydroxyl‐terminated polyether‐block‐polydimethylsiloxane (PESO) was synthesized as an intermediate through the hydrosilylation of SiH‐terminated polydimethylsiloxane with allyl polyoxyethylene polyoxypropylene ether. Then, carboxylated polyether‐block‐polydimethylsiloxane (CPES) was prepared through the reaction of maleic anhydride with PESO. First, the chemical structures of the synthesized polysiloxanes were characterized with IR and 1H‐NMR spectroscopy, and then the film morphology of CPES and the supermolecule self‐assembled from CPES and N‐β‐aminoethyl‐γ‐aminopropyl polydimethylsiloxane (ASO‐1) was investigated by atomic force microscopy in detail. Experimental results indicated that the superpolysiloxane that self‐assembled from CPES and ASO‐1 showed a film morphology very different from those of CPES and ASO‐1. There were not only many small, bright dots but also some big and marvelous dots circled by dots on the film surface. The morphology of dots circled by dots was estimated to result from aggregates of CPES micelles adsorbed onto the curled ASO‐1 molecule interface. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation, structural elucidation, molecular weight determination, and molecular recognition of first‐ and second‐tier dendrimer molecules
Authors: Singh Man , Yadav Dolly , Yadav Rajesh K.
Published: August 2008

1,3,5‐Triglyceratetriazine [first tier (G1)] and tri(1,3,5‐triglycerate) triazine [second tier (G2)] dendrimers were prepared with 1,3,5‐trichlorotriazine and sodium glycerate in a 1 : 3 mass ratio in an ethanolic medium.G1 and G2 were amorphous, white, solid substances. Their structures were elucidated with IR, 1H‐NMR, and 13C‐NMR, and their thermal stability was studied with thermogravimetric analysis. The activation energy was calculated with the Freeman–Carroll model. Densities, viscosities, and surface tensions for 0.01–0.08 mol/kg aqueous solutions increased at 0.01 mol/kg for sodium glycerate, 1,3,5‐trichlorotriazine, 1,3,5‐triazine triglycerate chloride, G1, and G2. These values were measured at 298.15 K. The apparent molal volume, reduced viscosity, and inherent viscosity were calculated from the densities and viscosities, respectively. The data were regressed for the limiting densities, limiting apparent molal volumes, intrinsic viscosities, limiting inherent viscosities, and limiting surface tensions for solute–solvent interactions. The positive limiting apparent molal volume values were noted in the order of G2 > 1,3,5‐triazine triglycerate chloride > G1 > 1,3,5‐trichlorotriazine > sodium glycerate, with weaker hydrophilic intermolecular interactions of G2. The higher intrinsic viscosity and limiting inherent viscosity values for G2 implied stronger G2–H2O hydrophilic interactions, and the higher limiting apparent molal volume of G2 indicated slightly higher dynamic conformational changes in comparison with G1, with stronger structural activities. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Group phantasy: its place in the psychology of genocide
Authors: Glass James M.
Published: August 2008

This paper explores the leading role that ideas and beliefs can play in the formation of groups and their political action, with particular reference to the psychology of groups and movements involved in genocide. The paper asserts the notion of the Idea as leader; thus moving away from Freud's more limited notion in “Group Psychology and the Analysis of the Ego” of the leader as a person, a charismatic figure generating feelings of love and attachment. Alluding to the work of Bion, Neri and Anzieu, the paper examines the political and psychological significance – the willed quality – of group phantasy in group‐initiated mass murder, from Nazi genocide to the ideology of radical Islamic terrorism. Copyright © 2008 John Wiley & Sons, Ltd.
The “strong leadership” of George W. Bush
Authors: Greenstein Fred I.
Published: August 2008

This paper further explores the phenomenon of the “strong leader” by presenting an account of President George W. Bush, whose early conduct in the White House seemed far from strong, but who rose to the challenge of the terrorist attacks on the US of September 11, 2001 and began to preside with authority and assertiveness over an administration that went to great lengths to put its stamp on the national and international policy agendas, but was intensely controversial in the policies it advanced. The paper provides a three dimensional account of Bush, reviewing his early years, political rise and presidential performance, and then analyzes his leadership style in terms of six criteria that have proven useful for characterizing and assessing earlier chief executives – emotional intelligence, cognitive style, effectiveness as a public communicator, organizational capacity, political skill, and the extent to which the president is guided by a realistic policy vision. Copyright © 2008 John Wiley & Sons, Ltd.
Political leaders and their publics
Authors: Walter James
Published: August 2008

This paper examines the psychological elements driving leaders and followers and the dynamic of their relationship to each other – with particular reference to recent Australian political leadership and experience. Building upon the work of Lasswell, Barber and Little, the paper analyses how political affect connects leaders and followers in the formation and mobilization of publics. The paper provides case studies of the leadership styles of three recent Australian Prime Ministers – Whitlam, Keating and Howard – and explores the resonance between the leader's world‐view and emotional signature and the salient beliefs and passions of their followers. Copyright © 2008 John Wiley & Sons, Ltd.
Luminescence Resonance Energy Transfer Sensors Based on the Assemblies of Oppositely Charged Lanthanide/Gold Nanoparticles in Aqueous Solution
Authors: Gu Jian‐Qin , Sun Ling‐Dong , Yan Zheng‐Guang , Yan Chun‐Hua
Published: August 2008

This work demonstrates luminescence resonance energy transfer (LRET) sensors based on lanthanide‐doped nanoparticles as donors (D) and gold nanoparticles as acceptors (A), combined through electrostatic interactions between the oppositely charged nanoparticles. Negatively charged lanthanide‐doped nanoparticles, YVO4:Eu and LaPO4:Ce,Tb, with high luminescence quantum yield and good water‐solubility, are synthesized through a polymer‐assisted hydrothermal method. Positively charged polyhedral and spherical gold nanoparticles exhibit surface plasmon resonance (SPR) bands centered at 623 and 535 nm, respectively. These bands overlap well with the emission of the Eu3+ and Tb3+ ions within the lanthanide nanoparticles. Herein, the gold nanoparticles are synthesized through a seed‐mediated cetyltrimethylammonium bromide (CTAB)‐assisted method. The assemblies of the oppositely charged donors and acceptors are developed into LRET‐based sensors exhibiting a donor quenching efficiency close to 100 %.
Kameralismus als paradoxe Konzeption der gleichzeitigen Stärkung von Markt und Staat. Komplexe Theorielagen im deutschen 18. Jahrhundert
Authors: Priddat Birger P.
Published: August 2008

Cameralism as the paradox concept of simultaneous strengthening of market and state. Complex theoretical constellations in Eighteenth Century's Germany. Cameralism is an early theory of political economy of the 17th and 18th century in Germany and Austria, defining markets as a mode of political order of the absolutistic state. Men are incomplete actors; the state has to arrange a secure life and well being. But all regulation and order is the basement for individual action and a certain kind of early liberty. To regulate men's actions is to protect them against any arbitrariness of the governor. In the shadow of strong regulation of the economy and the society we see the development of the liberal market society.