Highly Selective Behavior of a Silver Delafossite: Response Towards Wide Range of Hydrogen, Repeatability and Long Term Performance

Aging has a significant effect on performance of asphalt materials. Reliable characterization of asphalt binder properties with aging is crucial to improving asphalt binder specifications as well as modification and formulation methods. The objective of this study is to correlate the laboratory conditioning methods with field aging using evolution of binder rheological parameters with time and pavement depth. Loose mixtures are aged in the lab (5 and 12 days aging at 95°C, and 24 h at 135°C) and recovered binder rheological properties are compared with those from different layers of field cores. The virgin binder results with 20 h pressure aging vessel (PAV) aging are also included. Binder testing is conducted using a dynamic shear rheometer with a 4 mm plate over a wide range of frequencies and temperatures. Rheological parameters calculated from the master curves, performance grade system, and binder Christensen–Anderson–Marasteanu model are used to evaluate changes with aging. The field aging gradient is evaluated, and the laboratory conditioning durations corresponding with the field aging durations at different pavement depths are calculated. The results show that 5 days of aging can simulate around 8 years of field aging (in New Hampshire) for the top 12.5 mm pavement, and 12 days’ aging can simulate approximately 20 years; 20 h PAV binder aging is not adequate to capture the long-term performance of the pavement. This study provides a way to optimize the laboratory conditioning durations and evaluate the performance of asphalt material with respect to pavement life (time) and depth (location) within the pavement structure.

Download Full-text

Comprehensive Performance Evaluation of Multiscale Transportation Strategies: Large Metropolitan Planning Organization Methodology

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1858-18 ◽

2003 ◽

Vol 1858 (1) ◽

pp. 124-132 ◽

Cited By ~ 1

Author(s):

Brian J. Fineman ◽

Anthony J. DeJohn ◽

Keith E. Miller ◽

Lois M. Goldman

Keyword(s):

Long Range ◽

Time Frame ◽

Decision Makers ◽

The North ◽

Metropolitan Planning ◽

Wide Range ◽

Long Term Performance ◽

Term Performance ◽

Transportation Plan

Innovative structuring of the decision-making process has allowed a large metropolitan planning organization, the North Jersey Transportation Planning Authority (NJTPA), to face the challenge of cooperatively developing a long-range transportation investment agenda in a complex and diverse region. The wide range of applicable geographic scales is a problem when exploring alternative strategies in such a region, so a single, multiscaled, technically based planning analysis was designed and conducted to unify decision makers around a comprehensive set of performance goals and the estimated potential effects of all reasonable actions. The analysis, built within an accelerated 10-month time frame under federal scrutiny, relied on participation by elected officials, planners, engineers, and regional stakeholders. It produced a full regionwide identification of long-term performance needs and an exhaustive assessment and prioritization of location-specific strategies. NJTPA applied this prioritization to select strategies to update its long-range transportation plan and to develop specific immediate guidance for implementation agencies.

Download Full-text

Review of the performance of full-scale MBR plants: design, operation and on-site experimental data

Water Practice & Technology ◽

10.2166/wpt.2010.023 ◽

2010 ◽

Vol 5 (2) ◽

Cited By ~ 1

Author(s):

S.K. Pattanayak ◽

S. Chang ◽

M. Theodoulou ◽

V. Mahendraker

Keyword(s):

Full Scale ◽

Design Parameters ◽

Plant Design ◽

Treatment Technology ◽

Wide Range ◽

Pre Treatment ◽

Long Term Performance ◽

Term Performance ◽

Removal System

The membrane bioreactor (MBR) process has become an effective alternative wastewater treatment technology that produces effluent with excellent quality. Globally, a wide range of municipal and industrial MBR plants are in operation, varying both in size and complexity. The objective of this investigation was to develop a better understanding of the long term performance of MBR plants. To achieve this objective, eight full-scale municipal MBR plants were examined. The methodology included a review of plant design parameters, pre-treatment system, biological operation, membrane operation, disinfection system and nutrient removal system. In addition, on-site tests were done on permeate, final effluent and mixed liquor to understand MBR performance.

Download Full-text