bluuebunny/crossref_metadata_2025 huggingface dataset:
Engineered 2D Materials for Efficient Biosensors
Authors: Narayanan Tharangattu Narayanan , Ajayan Pulickel Madhavapanicker , Viswanathan Sowmya , Manickam Gurusaran , Renugopalakrishnan Venkatesan
Published: March 2015

The emergence of 2-dimensional (2D) materials could herald numerous advanced scientific methodologies for both fundamental and applied research. These ultrathin materials can be functionalized and, thus, have the potential to make new devices and sensors that are both highly efficient and sensitive. In addition to being mechanically robust, the 2D materials can be engineered to provide sensor architectures that further increase their inherent high surface area by creating 3D geometries using layer by layer assembly to make stacked devices that could potentially be transparent. The increased sensor surface area would deliver increased signal-to-noise and sensitivity. Here highly sensitive and selective electrochemical detection of bio-analytes using some of engineered 2D materials such as graphene nano-ribbons, fluorinated graphene, and molybdenum disulfide is presented. It is found that surface moieties, defects and surface charges in these ultra-thin layers result in enhanced electron transfer kinetics between the electrodes and biomolecules. This in turn results in an oxidation or reduction of biomolecules with a high peak current, indicating the possible uses of 2D materials for various point-of-care devices. A novel stable 3D electrode geometry has been found to have enhanced heterogeneous electron transfer properties compared to 2D electrodes and provides evidence that electrode geometry and surface area could significantly impact the performance of biosensors.
Towards a sustainable infrastructure company
Authors: Whitehead Chris
Published: March 2015

Engineers have an important role to play in creating a sustainable future. They occupy a pivotal position between known limits to growth, the imperative for change expressed quantitatively and practical action. It is a lack of understanding of the quantitative dimensions of sustainability that has led to campaigns such as 350.org's ‘Do the Math’ tour. This paper describes the sustainability journey of Balfour Beatty plc, and the tools and techniques that it has developed en route. It is intended as a frame of reference for engineers within infrastructure businesses, to help stimulate debate, establish priorities and shape their own sustainable future. The paper describes Balfour Beatty's progress from a position of naivety to where it scores highly on sustainability in prequalification evaluations and is able to act as a surrogate advisor to its clients when executing projects. It describes the critical dimensions of the company's approach, including how it maps onto the strategic framework for the business, governance, assurance, reporting and stakeholder engagement. The construct of sustainability continues to evolve both within and without the company, and the paper concludes with a summary of lessons learnt to date, a maturity model and a list of focus areas for future work.
Multiphase Flowmeter for Testing Heavy-Oil Wells in Offshore Brazil
Authors: Maizeret P.-D.. -D. , Rocha P.S.. S. , Danemberg Marsili M.. , de Almeida Ferreira I.. , Lipovetsky T.. , Schubert Junior E.. , Theuveny B..
Published: March 2015

In the heavy-oil Atlanta field, well-test operations were planned initially with a multienergy gamma ray/Venturi multiphase flowmeter as a contingency. During the well-test operations, the foaming propensity of the produced oil made it almost impossible to distinguish an interface between liquid and gas in the separator or tank, rendering the standard equipment useless. Only in the second test were some tank measurements available. The measurement principle used in this multiphase flowmeter, however, is not sensitive to foam or emulsion because the meter responds to the atomic-level composition of the different components of the mixture independently of their arrangement, providing accurate flow-rate measurements. Therefore, it became the main flowmetering device for the operator.

We detail the behavior of the multiphase flowmeter during the well tests in the Atlanta field and the challenges caused by this highly viscous oil. In the case of standard oils, the measurements are not sensitive to the viscosity value. However, in the case of low Reynolds numbers, the viscosity value can dramatically affect the results. In this case, some solvents were injected during the well test to reduce the liquid viscosity, and we present the consequences for the multiphase flowmeter. Because it was not possible to measure the viscosity directly at the wellsite, we highlight the work flow that was followed to determine the proper viscosity value to use. The viscosity number was validated by comparing the multiphase-flowmeter measurements to the gas/oil ratio measured in the laboratory on downhole samples from the same reservoir, to the water cut measured manually during the operations and to the tank total-liquid-rate measurements. Finally, we present some recommendations on the use of multiphase flowmeters for heavy-oil well tests.
Diversion Conditions for Viscoelastic-Surfactant-Based Self-Diversion Acid in Carbonate Acidizing
Authors: Mou Jianye , Liu Ming , Zheng Kexiang , Zhang Shicheng
Published: March 2015

The success of matrix acidizing in carbonates is often dependent on the efficiency of diversion agents, especially for treatments on wells with thick formations or multiple zones, or horizontal wells with long and heterogeneous intervals. Viscoelastic-surfactant (VES) -based self-diversion acid has been used successfully in fields because of its negligible damage to the formation and good diversion ability. Although the diversion ability of VES acid was studied experimentally with small core plugs, the diversion conditions of VES acid under in-situ radial conditions need to be studied. In this paper, we develop a VES radial-acidizing model that simulates VES acid flow, acid/rock reaction, porosity variation, viscosifying, wormholing, and acid diversion in multiple zones. On the basis of the model, extensive numerical simulations are conducted to investigate wormholing behavior of the VES acid, the factors that affect the diversion ability of VES acid, and the diversion conditions of VES acid. The study shows that the VES acid-dissolution patterns depend on the injection rate, and there is an optimum injection rate under which the dominant wormholes are formed. Compared with regular acid, the VES acid provides better acid placement for heterogeneous intervals. The intervals with separation shorter than approximately 150 m can be acidized together with VES acid if the two intervals have a close permeability with no perforation between them. The permeability ratio of the two intervals has remarkable influence on the diversion performance of VES acid. Even though the viscosified fluid acts as a temporary barrier to prevent the fluid from flowing into the higher-permeability formation, the VES acid reduces diversion effectiveness for large permeability contrast. We also investigated the combined effect of permeability contrast and separation of the two intervals on diversion performance. This study provides a basis to select diversion technology and a method to evaluate diversion performance of VES acid for field-acidizing treatments.
Fuzzy logic and fuzzy set theory based edge detection algorithm
Authors: Peric Nebojsa
Published: March 2015

In this paper we will show a way how to detect edges in digital images. Edge
detection is a fundamental part of many algorithms, both in image processing
and in video processing. Therefore it is important that the algorithm is
efficient and, if possible, fast to carry out. The fuzzy set theory based
approach on edge detection is good for use when we need to make some kind of
image segmentation, or when there is a need for edge classification (primary,
secondary, ...). One example that motivated us is region labeling; this is a
process by which the digital image is divided in units and each unit is given
a unique label (sky, house, grass, ?, etc.). To accomplish that, we need to
have an intelligent system that will precisely determine the edges of the
region. In this paper we will describe tools from image processing and fuzzy
logic that we use for edge detection as well as the proposed algorithm.
Congenital Renal Tumor: Metanephric Adenoma, Nephrogenic Rest, or Malignancy?
Authors: Yin Mlnzhi , Cai Jiaoyang , Thorner Paul Scott
Published: March 2015

We report a renal tumor detected by prenatal ultrasound and resected at 2 months of age. This 9-cm, solid mass was composed of tubular and papillary structures lined by small, uniform epithelial cells. There was local invasion into renal parenchyma and a tumor deposit in a hilar lymph node. The tumor was immunopositive for WT1, pankeratin, and CD10; focally positive for CK7; and negative for EMA and TFE3. Based on morphology and immunophenotype, the favored diagnosis was metanephric adenoma over Wilms tumor, renal cell carcinoma, and nephrogenic rest. However, metanephric adenoma only occasionally occurs in children and has never been reported prenatally. Alternatively, this tumor might be a congenital Wilms tumor that differentiated completely. Although the nature of the tumor remains unconfirmed, resection appears to have been curative; the patient remains disease-free 18 months following surgery alone.
Photoelectron Spectroscopy for Chemical Analysis
Authors: Rensmo Håkan , Siegbahn Hans
Published: March 2015

Photoelectron spectroscopy started its modern development in the fifties based on techniques for studies of nuclear decay. Since then, photoelectron spectroscopy has undergone a dramatic expansion of application and is now a prime research tool in basic and applied science. This progress
has been largely due to the concomitant development of photon sources, sample handling and electron energy analyzers. The present article describes some of the salient features of modern photoelectron spectroscopy and its applications with particular emphasis on energy relevant issues.
All aboard at all Doors
Authors: Stewart Colin , El-Geneidy Ahmed
Published: March 2015

The time that buses spend waiting for passengers to board can be a significant portion of a bus route's overall running time. A key determinant of boarding time is the number of doors through which passengers are permitted to board. Transit agencies that allow boarding through all doors, instead of just through the front door, typically enjoy decreased boarding times and decreased running times. This study focused on the feasibility of an all-door boarding policy for La Société de transport de Montréal (STM), the public transit agency of Montreal, Canada. The potential benefits of such a policy were assessed through three main steps. First, a selection methodology was developed to determine which of STM's bus routes would benefit most from various all-door boarding strategies. Second, a multivariate regression analysis was implemented with STM's archived automatic vehicle location and automatic passenger counter data to estimate the dwell and running-time savings that would result under various implementation scenarios. Third, a sensitivity analysis was developed to demonstrate the savings associated with implementing the policy. The findings showed that all-door boardings could yield substantial savings in running time, with morning peak savings as much as 15.8% on the best routes. In many cases, the running-time savings were enough to remove a bus from a route while still maintaining existing frequencies. The findings from this research may be beneficial for transit planners and operators since the presented methodologies show substantial savings from all-door boarding and can be adopted by other transit agencies.
Buses with High Level of Service in Nantes, France
Authors: Conies Emilio , Novales Margarita , Orro Alfonso , Anta Javier
Published: March 2015

This study identified and analyzed the reasons that have led the BusWay of Nantes, France, to be one of the most, if not the most outstanding and successful case of setting up a bus with high level of service (BHLS) system in European cities. The lessons and the conclusions from the study may be applicable to and useful for other sites with similar conditions. The analysis examined the measures that were implemented (infrastructure, vehicles, design of transit service operations, complementary facilities and services, and branding) and the results (level of service in frequencies and operating speed, reliability of schedules, ridership, and traffic safety). Furthermore, as BHLS and light rail transit (LRT) are integrated in the same level of the trunk network in Nantes, the city provided a relatively level playing field to develop an equitable comparison of the two systems. Through the case study of Nantes, the study found that the BHLS system was suitable for meeting demand volumes in the range from 1,000 to 2,500 passengers per hour in one of both directions during peak hours with a level and quality of service very near the LRT, but with more moderate investment costs and higher flexibility.
Modeling Bus Dwell Time with Decision Tree-Based Methods
Authors: Rashidi Soroush , Ranjitkar Prakash , Hadas Yuval
Published: March 2015

A large proportion of transit travel time is made up by dwell time for passengers boarding and alighting. More accurate modeling and estimation of bus dwell time (BDT) can enhance the efficiency and reliability of the public transportation system. Multiple linear regression (MLR) has been the most commonly used method in the literature for modeling and estimating BDT. However, the underlying assumptions of the MLR method, such as multicollinearity and normality of random error, cannot always be satisfied for real applications. This study developed and implemented two methods based on decision trees (DTs), namely, classification and regression tree and chi-squared automatic interaction detector, for the first time for BDT modeling and estimation. The models were compared with the traditional MLR model after calibrating and validating the new models against the data collected from four bus stops in Auckland, New Zealand. Various error measurements were used to evaluate the accuracy of the models. The DT-based methods eliminated the limitations of the MLR method and provided reliable and accurate estimation of BDT.
Quantifying the Effects of Modal Conflicts on Transit Reliability
Authors: Wickland Teo , Sall Elizabeth
Published: March 2015

Residents of San Francisco, California, have repeatedly cited transit reliability as one of their top concerns. As San Francisco has begun investing in projects to reduce travel time variability, the trade-offs between alternatives have been difficult to quantify with existing tools. This study investigated and quantified the effects of modal conflicts on bus travel along a 3.6-mi study corridor and each conflict's contribution to unreliability. Instances of modal conflict were modeled as Bernoulli trials or other simple probabilistic events and included vehicles entering or exiting parking spaces, double-parked vehicles, and vehicles queuing for pedestrians while executing turning movements. Cumulative distributions of modal conflict resulted in estimates of average delay and variance of delay from bus to bus. Sensitivity analyses illustrated and quantified the nonlinearity and variance of delay with respect to the number and severity of events. The convolution of distributions of delay for each conflict type could also be calculated, provided the causes of delay were independent. Modal conflict delay for a side-running bus rapid transit line in the study corridor was 1.9 min longer for buses with 95th percentile delays than for those with the mean delay of 4.2 min. Overall, the semi—standard deviation of delay compared with a no-modal-conflict reference point was 4.3 min. Furthermore, eliminating the analyzed modal conflict types along the study corridor–for instance, by establishing center-running bus-only lanes–could reduce system operating costs by up to $2.5 million per year and could result in user time savings equivalent to as much as $10.5 million per year.
Flex Scheduling for Bus Arrival Time Prediction
Authors: Hernandez Troy
Published: March 2015

The prediction of bus arrival times is an important element for travel planning. This study used three weeks of Chicago, Illinois, Transit Authority bus route GPS data to compare the performance of several commonly used methods and algorithms. The use of implicit schedules in previous papers was inadequate. The use of additional information, such as recent travel times along the route, is unnecessary. In addition, the use of computationally intensive machine learning algorithms, such as support vector regression, k nearest neighbor regression, and neural networks, is unnecessary. The study used basis expansion functions at various resolutions with linear models and cross-validated the models to determine explicitly the approximate historical interstop travel times for any time of the day and any day of the week. Combining the estimated interstop travel times with the real-time GPS location of a bus resulted in a flex schedule that was independent of scheduled departure or arrival times. Using a flex schedule makes the use of additional GPS information or the use of the machine learning algorithms unnecessary.
Empirical Analysis of Controller Event Data to Select Vehicle Detector Fault Triggers
Authors: Audelo Michael , Chou Chih-Sheng , Chen Tiantian , Nichols Andrew P.
Published: March 2015

The proper detection of both vehicles and pedestrians is critical for operations of signalized intersections, especially intersections with adaptive traffic signal control. Faulty detectors must be identified as quickly as possible so that they can be repaired and their erroneous output corrected (e.g., preventing an adaptive algorithm from continuing to allocate green time to a detector that is stuck on). This study establishes a procedure to determine static detector fault thresholds (e.g., maximum detector on time and maximum detector off time) that can be programmed into a traffic signal controller. This procedure analyzes detector on and off durations over multiple days to define distributions of those parameters. The study analyzes data for 154 detectors in Morgantown, West Virginia, to generate on and off distributions and calculate the resulting 90th, 95th, and 99th percentile values. The detectors are divided into three groups on the basis of their physical locations relative to the intersection (e.g., stop bar or advance) and the approach function (e.g., mainline or minor). Default thresholds for the three groups are recommended for the signal system through the application of a 95% confidence limit to the 99th percentile values and local knowledge of the system. The procedure defined here can be applied to other signal systems to determine these thresholds.
Development and Evaluation of Adaptive Transit Signal Priority Control with Updated Transit Delay Model
Authors: Han Xu , Li Pengfei , Sikder Rajib , Qiu Zhijun (Tony) , Kim Amy
Published: March 2015

Transit signal priority (TSP) strategies are widely used to reduce bus travel delay and to increase bus service reliability. State-of-the-art strategies enable dynamic (and optimal), rather than predetermined, TSP plans to reflect real-time traffic conditions. These dynamic plans are called adaptive TSP. Existing adaptive TSP strategies normally use a performance index (PI), which is a weighted summation of all types of delays, to evaluate each candidate TSP plan and the weights to reflect the corresponding priority. The performance of an adaptive TSP depends on three factors: delay estimation, weights determination, and optimization formulation. In this context, there are three key academic contributions: (a) an enhanced bus delay estimation model based on advance detection, (b) a mechanism to adjust the PI weights dynamically to reflect the changing necessity of TSP under different conditions, and (c) TSP optimization formulated into a quadratic programming problem with an enhanced delay-based PI to obtain global optimization with the use of MATLAB solvers. In addition, an adaptive TSP simulation platform using a full-scale signal simulator, ASC/3, in VISSIM was developed. The optimal TSP plans were granted or were rejected on the basis of TSP events, such as check-in, check-out, and multiple TSP requests. Through a case study in VISSIM, this research found that, compared with conventional active TSP strategies, the new adaptive TSP strategy could further reduce bus travel time while maintaining a better balance of service on non-TSP approaches along a 7.4-km bus corridor in Edmonton, Alberta, Canada.
Multiattribute Decision-Making Methods for Optimal Selection of Traffic Signal Control Parameters in Multimodal Analysis
Authors: Medina Juan C. , Lo Eric G. , Benekohal Rahim (Ray) F.
Published: March 2015

The selection of optimal traffic signal timing parameters has traditionally been based on improving traffic operation for motorized vehicles. This approach is rapidly changing. Other modes of transportation, such as pedestrians, bicycles, and transit, are being considered, and multiple attributes are used in the decision-making process. This research explores the use of three well-known methods for multiattribute decision making (MADM) to select optimal traffic signal control parameters in a multimodal scenario. For policy makers MADM methods provide enough flexibility to incorporate a variety of characteristics from different modes of transportation to operate traffic signals, including demands, occupancy of each moving unit, and priority. The methods explored are simple additive weighting, analytical hierarchical process, and technique for order preference by similarity to ideal solution. These methods are used with three performance measures: delay based on unit, delay based on occupancy, and delay based on occupancy and priority. Traffic signal parameters are optimized by ranking a series of possible solutions. The three methods are demonstrated and compared for a case study intersection at two volume levels; passenger cars, buses, bicycles, and pedestrians are considered.
Optimal Deployment of Hybrid Alternative Power System at Signalized Intersections
Authors: Zhao Mo , Sharma Anuj
Published: March 2015

Traffic signal power failures can degrade efficiency and safety at intersections that warrant traffic signal control. Alternative power sources (APSs) are typically used to supply traffic signals in power outages. Agencies that operate signals need a decision-making framework to identify locations and deployment schedules for APS installation. This paper presents a methodology for optimal deployment of APSs at signalized intersections. This methodology can also be used to investigate the economic viability of using wind and solar energy as APSs for signalized intersections. Benefit–cost analysis is used as an economic tool. The primary benefit of an APS is improving traffic operation efficiency and safety. The renewable energy sources, if harnessed, would add energy production and environmental benefits. The methodology this research presents can be adapted to site-specific conditions by appropriately choosing the model inputs. A case study is provided to demonstrate the step-by-step implementation of the proposed methodology.
Mitigating Right-Turn Conflict with Protected Yet Concurrent Phasing for Cycle Track and Pedestrian Crossings
Authors: Furth Peter G. , Koonce Peter J. , Miao Yu , Peng Fei , Littman Michael
Published: March 2015

Where there are high turn volumes or speeds, pedestrian and bicycle crossings may need to be protected from right turns as well as left turns. Cycle tracks may need protected crossings even where right-turn volumes are modest. This research explores a phasing scheme in which right turns have their own phase and bike and pedestrian crossings run in their own distinct phase concurrent with the parallel vehicular through phase. This protected yet concurrent phasing scheme is more efficient than an all-pedestrian phase. A general framework for sequencing phases accounting for the right turn and crossing conflict is shown with four rings instead of the usual two. Seven examples of protected yet concurrent phasing from the United States and the Netherlands illustrate the scheme and characterize its likely impacts in terms of delay and street footprint. Overall delay and footprint impacts are found to be modest; factors that affect the impact of protected phasing include complexity of the phasing plan, coordination, and the possibility of using reservice. Because protected yet concurrent phasing makes efficient use of time, this phasing is also economical with space. Although the phasing requires right-turn lanes, its use can reduce the necessary number of through lanes, especially in comparison with all-pedestrian phasing.
Performance-Based Moisture Susceptibility Evaluation of Warm-Mix Asphalt Concrete through Laboratory Tests
Authors: Lee Jong-Sub , Kim Y. Richard
Published: March 2015

This study used the cyclic direct tension test, indirect tensile strength test, and Hamburg wheel tracking device (HWTD) test to evaluate the moisture susceptibility of warm-mix asphalt (WMA) mixtures. The stripped areas that were quantified by digital imaging analysis were derived from the cyclic direct tension, indirect tensile strength, and HWTD tests and were compared with the mechanical properties of the mixtures to identify sensitive moisture susceptibility indicators. These methods were applied to a Superpave® 9.5-mm hot-mix asphalt mixture and five corresponding WMA mixtures that used the following technologies: (a) Evotherm 3G that contained a chemical additive, (b) foaming, (c) WMA-A that contained a chemical additive and was under development, (d) WMA-B that contained an organic additive and was under development, and (e) WMA-C that also contained an organic additive (different from that used in WMA-B) and was under development. Fatigue life ratios obtained from the simplified viscoelastic continuum damage model combined with layered viscoelastic analyses were determined to be the most sensitive indicators for moisture susceptibility. The stripping infection points derived from the HWTD tests also showed good sensitivity to moisture conditioning; however, each stripping infection point was affected by the permanent deformation characteristics of a given mixture as well as its moisture susceptibility; therefore, the observation was inconclusive.
Friction Study of Long-Term Pavement Performance Special Pavement Study 9A Sections in Connecticut
Authors: Yut Iliya , Henault John W. , Mahoney James
Published: March 2015

Pavement surface friction is one of the most important contributing factors in highway safety. It is a function of a pavement's micro- and macro texture. Therefore, tracking changes in pavement surface friction and texture depth during a pavement's service life is critical for maintaining driving safety and comfort. As part of FHWA's Long-Term Pavement Performance (LTPP) study, many state highway agencies have been collecting friction data to track these changes on designated test sections. In Connecticut, six LTPP sections were constructed in 1997 to serve as Special Pavement Study 9A sites for the characterization of Superpave® asphalt mixtures. This paper presents an analysis of pavement friction and texture data collected by the Connecticut Department of Transportation on these sections. Friction numbers were obtained with an ASTM E274 locked-wheel pavement friction tester by using smooth (ASTM E524) and ribbed (ASTM E501) tires and a GripTester fixed-slip pavement friction tester. Estimated texture depths were obtained in accordance with ASTM E1845 at each site with a Dynatest laser texture device mounted to the friction tester. In addition, mean profile depths were measured with a Circular Track Meter in accordance with ASTM E2157. The analysis of the results targeted three main objectives. First, the variability of the skid number values, measured by the locked-wheel and the braked-wheel, fixed-slip methods, was evaluated. Next, some empirical relationships between friction number and texture depth developed in previous studies were verified. Last, the friction and texture data were analyzed to correlate the measurements with surface material properties.
Safety Aspects of Wet Asphalt Pavement Surfaces through Field and Numerical Modeling Investigations
Authors: Srirangam S. K. , Anupam K. , Scarpas A. , Kasbergen C. , Kane M.
Published: March 2015

Good pavement macrotexture has a direct influence on vehicle safety during wet weather conditions by improving vehicle traction and braking ability. Apart from the macrotexture, several other factors, such as environmental, tire, and pavement-related characteristics, affect the wet friction. Most experimental studies had a limited scope of reusability as soon as there was a change in any of the other factors. In recent years, the development of powerful finite element tools has made it possible to simulate complex wet tire–pavement interaction as close as possible to the actual field conditions. However, to the best of the authors’ knowledge, none of the past analytical and numerical studies were able to include the actual pavement surface texture in their analysis. This paper describes an approach to study the effect of actual surface morphologies of asphalt pavements on the wet friction coefficient by using the finite element method. Asphalt surface morphologies representative of open-graded mix to close-graded mix were used in the finite element analysis. The finite element model was duly calibrated with the field investigations conducted with state-of-the-art field equipment. The extreme loss of wet friction, which ultimately led to the risk of hydroplaning, was also studied. The analyses were performed for two water film thicknesses, two tread patterns, and two tire slip ratios. The results from the current study can be used as safety indicators of in-service asphalt pavements under wet and flooded conditions.
Moisture Susceptibility Evaluation of Nanosize Hydrated Lime-Modified Asphalt–Aggregate Systems Based on Surface Free Energy Concept
Authors: Diab Aboelkasim , You Zhanping , Hossain Zahid , Zaman Musharraf
Published: March 2015

Moisture susceptibility can cause cohesive and adhesive failures in the asphalt–aggregate system, resulting in serious pavement distresses. The role of regular hydrated lime (RHL) as an antistripping agent in asphalt pavements has been widely addressed with traditional moisture susceptibility evaluation methods. However, the use of nanosize hydrated lime (NHL) in asphalt industries has not yet been initiated. The first objective of this study was to assess the RHL- and NHL-modified asphalt binders on the basis of the surface free energy (SFE) concept by using the Wilhelmy plate method. Advera, a warm-mix asphalt (WMA) foaming additive, was added to the hydrated lime-(RHL and NHL) modified asphalt binders to address the effect of foaming on cohesive bond strength. The NHL material was added with particle sizes of 50 and 100 nanometers. The second objective was to address the adhesive bond strength between the aforementioned asphalt binders and different aggregates. Different acidic and basic aggregates with known SFE components were used along with measured SFE components of the asphalt binders to determine quantitatively the free energy of adhesion in the system. Overall results reveal that SFE components of asphalt binders are dependent on the particle size of hydrated lime. In general, the cohesive bond of the NHL-modified asphalt binder was higher than that of the RHL-modified binder. As hydrated lime particle size decreases, dry and wet adhesive bonds increase. Moisture susceptibility of Advera-foamed mixes seems to depend on aggregate type. The NHL-modified mixes are expected to perform better than RHL-modified mixes in dry and wet conditions.
Evaluation of Warm-Mix and Rubber-Modified Open-Graded Friction Course Test Sections Made without Fibers in South Carolina
Authors: Putman Bradley J. , Lyons Kimberly R.
Published: March 2015

This paper summarizes the performance of open-graded friction course (OGFC) mixtures used to construct two experimental pavement test sections in South Carolina. The study's main objective was to evaluate OGFC mixtures made without fibers. One test section consisted of three OGFC mixtures [control with cellulose fibers, ground tire rubber modified without fibers, and warm-mix asphalt (WMA) without fibers], and the second consisted of two OGFC mixtures (control with cellulose fibers and WMA without fibers). Material was sampled from the asphalt plant during production. Tests were conducted on the fresh mix as well as specimens compacted at the plant and after reheating in the research lab. Results showed that the removal of fibers from the OGFC mixtures in both projects did not have any detrimental effects on the mix performance (drain down, permeability, abrasion resistance, indirect tensile strength, and fatigue resistance). The WMA mixture made with Evotherm exhibited increased fatigue resistance compared with the control mixture even though the WMA mixture did not contain cellulose fibers. In addition, the WMA mixture showed the potential to reduce heat loss resulting from the startup of the paving operation (i.e., running asphalt mix through a cold material transfer vehicle and then a cold paver). Limiting heat loss could improve the consistency of the OGFC mat density from the beginning transverse cold joint and thus potentially enhance the pavement performance.
Reporting Results from the Hamburg Wheel Tracking Device
Authors: Schram Scott , Williams R. Christopher , Buss Ashley
Published: March 2015

As the list of states adopting the Hamburg wheel tracking device continues to grow, there is a need to evaluate how the results are used. AASHTO T-324 does not standardize the analysis and reporting of test results. Furthermore, the processing and the reporting of the results of manufacturers are not uniform. This inconsistency is partly the result of the variation of agency reporting requirements. Some requirements include only the midpoint rut depth; others include the average across the entire length of the wheel track. No guidance is given when the stripping infection point (SIP) is reported. To eliminate bias in reporting, statistical analysis was performed on more than 135 test runs on adjoining gyratory specimens. Measurement location was found to be a source of significant variation for rut depth in the Hamburg wheel tracking device. This variation was likely the result of the nonuniform wheel speed across the specimen, geometry of the specimen, and air void profile. Eliminating this source of bias when rutting results are reported is feasible although the feasibility depends on the average rut depth at the final pass. When the results of a test that has an average rut depth of less than 12 mm at the final pass is reported, the average of the measurements along a 6.4-in. path beginning at 0.5 in. from the specimen edge nearest the gear housing should be reported. When the average final-pass rut depth is greater than 12 mm, it is reasonable to report the average of the measurements just off the center of the rutting track along a 3.2-in. path beginning at 2.1 in. from the specimen edge nearest the gear housing. SIP values were also analyzed. It is reasonable to report the average of the SIP values across all locations while calculated values measured more than 2 in. from the specimen's edge are discarded and for cases in which the ratio of the stripping slope to creep slope exceeds 2.0. Validation is needed for multiple machines.
Load Transfer Characteristics of Precast Portland Cement Concrete Panels for Airfield Pavement Repairs
Authors: Priddy Lucy P. , Pittman David W. , Flintsch Gerardo W.
Published: March 2015

Portland cement concrete pavement repair technologies using precast portland cement concrete panels have been investigated for decades and recently have gained acceptance and increased use in the United States for highway pavements but have had only limited use for airfields. The recent field testing of a new airfield precast panel repair system indicated that precast panels were suitable for expedient airfield pavement repairs; the panels could withstand between 5,000 and 10,000 passes of C-17 aircraft traffic. Failure of the panels was due to spalling of the transverse doweled joints. The purpose of this study was to determine the load transfer effectiveness, or load transfer efficiencies (LTEs), of the panel repairs. A heavy weight deflectometer was used to collect defection data before, during, and after trafficking to calculate precast panel LTE on the basis of defections (LTEd) or transferred stresses (LT). The LTE values were then evaluated to determine whether current measures of effectiveness were suitable for precast panel repairs. From the results of this investigation, few of the joints provided the current military airfield design assumption of 25% LT, but the majority of the transverse joints exceeded the proposed LTEd threshold of 70% even after failure of the transverse joints. It was recommended that additional field tests be conducted without the use of rapid-setting grout in the joints before recommendations on thresholds were made.
Analytical Approach for Predicting Three-Dimensional Tire–Pavement Contact Load
Authors: Hernandez Jaime A. , Gamez Angeli , Al-Qadi Imad L. , De Beer Morris
Published: March 2015

Three-dimensional tire–pavement contact loads of two truck tires–-a new-generation wide-base tire (WBT) and a dual tire assembly (DTA)–-were measured and analyzed. Extreme and typical values of tire inflation pressure (552, 690, 758, and 862 kPa) and tire loading (26, 35, 44, 62, and 79 kN) were considered in the experimental program. The measurements were performed with the stress-in-motion Mk IV system at the Council for Scientific and Industrial Research in South Africa. Peak values in three directions were compared, and the importance of tangential contact stresses was highlighted. In addition, characteristic variations of the measurements in the longitudinal, transverse, and vertical directions were identified. A function depending on two regression parameters, applied load, and distance along the contact length was proposed to represent the contact load in the vertical and transverse directions. An analysis was performed on the measurements to obtain the regression parameters, and a simplified procedure was proposed to determine tire–pavement contact loads. The contact area and contact length of the WBTs and the DTA were also compared.
Sensitivity Analysis of Field-to-Laboratory Subgrade Conversion Factors with AASHTOWare Pavement ME Design
Authors: El-Hakim Mohab , Jadoun Fadi M. , Lee Stephen , Ningyuan Li
Published: March 2015

The new AASHTOWare Pavement ME design software incorporates conversion factors into its procedure to correlate the field subgrade soil resilient modulus, measured with the falling-weight deflectometer, with the laboratory equivalent modulus for use in performance prediction. The national conversion factors recommended for use with Pavement ME were determined on the basis of data obtained from the Long-Term Pavement Performance database and were not necessarily accurate for all regions and soil types. Sensitivity analysis results are presented for the effect of field-to-laboratory subgrade modulus conversion factors on the performance of three types of pavement structures in Ontario, Canada: conventional flexible, deep-strength flexible, and composite. This work included simulation of real-world case studies extracted from the Ontario provincial pavement management system (Ontario PMS2) database. Three projects were selected for this study–-Highway 6, Highway 401, and Queen Elizabeth Way–-all located in southwestern Ontario. Required inputs including traffic, material characteristics, and layer thickness information were extracted from PMS2 and used to set up the projects in AASHTOWare Pavement ME. The AASHTOWare Pavement ME was executed with ranges of field-to-laboratory conversion factors for different pavement types. Statistical analyses were carried out to evaluate the effect of changing conversion factors on predicted performance. Study results suggest that the predicted performance of conventional flexible pavement is significantly affected by the subgrade modulus conversion factor. However, the impact of subgrade modulus conversion factors on predicted performance is insignificant for composite and deep-strength flexible pavement sections.
Sea-ice surface roughness estimates from airborne laser scanner and laser altimeter observations in Fram Strait and north of Svalbard
Authors: Beckers Justin F. , Renner Angelika H.H. , Spreen Gunnar , Gerland Sebastian , Haas Christian
Published: March 2015

We present sea-ice surface roughness estimates, i.e. the standard deviation of relative surface elevation, in the Arctic regions of Fram Strait and the Nansen Basin north of Svalbard acquired by an airborne laser scanner and a single-beam laser altimeter in 2010. We compare the scanner to the altimeter and compare the differences between the two survey regions. We estimate and correct sensor roll from the scanner data using the hyperbolic response of the scanner over a flat surface. Measurement surveys had to be longer than 5 km north of Svalbard and longer than 15 km in Fram Strait before the statistical distribution in surface roughness from the scanner and altimeter became similar. The shape of the surface roughness probability distributions agrees with those of airborne electromagnetic induction measurements of ice thickness. The ice in Fram Strait had a greater mean surface roughness, 0.16 m vs 0.09 m, and a wider distribution in roughness values than the ice in the Nansen Basin. An increase in surface roughness with increasing ice thickness was observed over fast ice found in Fram Strait near the coast of Greenland but not for the drift ice.
Filming Dance: Embodied Syntax in Sasha Waltz's S
Authors: Fielding Helen A.
Published: March 2015

This paper brings Merleau-Ponty's phenomenological approach to Sasha Waltz's dance film S, which focuses on the relation between sexuality and language. Maintaining that movement in cinema takes place in the viewers and not the film, the paper considers how the visual can be deepened to include the ways we move and are moved. Saussure's insights into language are brought to the sensible, which is here understood in terms of divergences from norms. Though film would seem to privilege vision, viewing this film helps to elucidate Merleau-Ponty's claim that a film succeeds when it engages the viewer's embodied understanding, and shifts the norms of the corporeal schema.
Contextualisation and typology of disc-headed and trapezoidal gravemarker forms in Scotland
Authors: Thomson George
Published: March 2015

Two distinctive small funerary artefact types, disc-headed and trapezoidal gravemarkers, are described. Both are uncommon in Scotland. Small disc-headed gravemarkers are distributed throughout the country but, with two exceptions, trapezoidal gravemarkers are restricted to the Shetland Islands. All known examples of these objects, including some not previously reported, are detailed and discussed in the context of similar artefacts in the rest of Britain and Europe. The current confusion in the use of names for these marker types and their variants is addressed and, through the construction of two separate typologies, a practical taxonomy is suggested. It is also suggested that both these gravemarker forms may represent examples of convergent cultural evolution.
A Novel Approach to the Design of Axial-Flux Switched-Reluctance Motors
Authors: Lambert Tim , Biglarbegian Mohammad , Mahmud Shohel
Published: March 2015

This paper presents the design of a new axial-flux switched-reluctance motor (AFSRM) topology for in-wheel drive vehicle applications. The features of the topology include a short flux path and an outer-rotor configuration. The proposed topology also uses a sintered-lamellar soft magnetic composite core material, and permits displacement of the rotor along the suspension axis, which reduces damage to the stator caused by impacts and vibrations. The combination of these features makes this new topology competitive with other in-wheel motors in regard to torque density, durability, and cost. To describe the behaviour of the topology, a model of the topology is developed using a new integral inductance function. That model is used to select the design parameters of an 8/6 AFSRM, for which a fuzzy controller is also developed to control the phase current. Several simulations of the 8/6 AFSRM are performed to calculate its energy conversion efficiency, thermal performance, and torque density, and results indicate that the new AFSRM has a higher energy conversion efficiency, and can produce more torque/kg than other switched-reluctance motors used for in-wheel drive vehicle applications.
Theoretical and Experimental Electrostatic Potential around the m-Nitrophenol Molecule
Authors: Drissi Mokhtaria , Benhalima Nadia , Megrouss Youcef , Rachida Rahmani , Chouaih Abdelkader , Hamzaoui Fodil
Published: March 2015

This work concerns a comparison of experimental and theoretical results of the electron charge density distribution and the electrostatic potential around the m-nitrophenol molecule (m-NPH) known for its interesting physical characteristics. The molecular experimental results have been obtained from a high-resolution X-ray diffraction study. Theoretical investigations were performed using the Density Functional Theory at B3LYP level of theory at 6-31G* in the Gaussian program. The multipolar model of Hansen and Coppens was used for the experimental electron charge density distribution around the molecule, while we used the DFT methods for the theoretical calculations. The electron charge density obtained in both methods allowed us to find out different molecular properties such us the electrostatic potential and the dipole moment, which were finally subject to a comparison leading to a good match obtained between both methods. The intramolecular charge transfer has also been confirmed by an HOMO-LUMO analysis.
DNA/Ag Nanoparticles as Antibacterial Agents against Gram-Negative Bacteria
Authors: Takeshima Tomomi , Tada Yuya , Sakaguchi Norihito , Watari Fumio , Fugetsu Bunshi
Published: March 2015

Silver (Ag) nanoparticles were produced using DNA extracted from salmon milt as templates. Particles spherical in shape with an average diameter smaller than 10 nm were obtained. The nanoparticles consisted of Ag as the core with an outermost thin layer of DNA. The DNA/Ag hybrid nanoparticles were immobilized over the surface of cotton based fabrics and their antibacterial efficiency was evaluated using E. coli as the typical Gram-negative bacteria. The antibacterial experiments were performed according to the Antibacterial Standard of Japanese Association for the Functional Evaluation of Textiles. The fabrics modified with DNA/Ag nanoparticles showed a high enough inhibitory and killing efficiency against E. coli at a concentration of Ag ≥ 10 ppm.