Technical Report EL-88-18: Reliability of the Federally Owned Water Main System

The reliability of the Federally Owned Water Main (FOWM) system was examined, and recommendations to improve system reliability are made. The existing FOWM system is very dependent upon three different pipe links. The first and most important link is the Francis Scott Key Bridge river crossing. This link carries the entire FOWM supply, and if taken out of service, an alternate means of supply must be used. At present, the only alternate source of supply is through interconnections with the adjacent Arlington County, Virginia, system. The second vital link is the 30-in. steel main which extends from the Key Bridge river crossing to the Pentagon. This line carries approximately 83 percent of the total delivery to the FOWM system. If taken out of service, all flow in the FOWM system would have to be routed through the 16-in. main along George Washington Parkway and Eisenhower Drive. During periods of high water use, flow in this 16-in. line would cause excessive friction losses. As a result, adequate system pressures cannot be maintained, and system demands cannot be fully met. The final critical pipe link is the feed to National Airport. This link consists of a 24-in. pipe and a 16-in. pipe connected in series. At present, this is the only source of water for National Airport. If this line were taken out of service, an alternate source of supply must be found. Furthermore, the available fire flow to the airport through this line during maximum daily demands falls below Insurance Services Office requirements. Several system improvements were evaluated to determine their contribution to the overall reliability of the FOWM system. System improvements consisted of operating existing and new interconnections, constructing new river crossings, installing a new storage tank, new line construction, and combinations of the above. System improvements were evaluated and ranked based on hydraulic performance, engineering impact, and total cost

Role of the hydrological cycle in regulating the planetary climate system of a simple nonlinear dynamical model

International audienceWe present the construction of a dynamic area fraction model (DAFM), representing a new class of models for an earth-like planet. The model presented here has no spatial dimensions, but contains coupled parameterizations for all the major components of the hydrological cycle involving liquid, solid and vapor phases. We investigate the nature of feedback processes with this model in regulating Earth's climate as a highly nonlinear coupled system. The model includes solar radiation, evapotranspiration from dynamically competing trees and grasses, an ocean, an ice cap, precipitation, dynamic clouds, and a static carbon greenhouse effect. This model therefore shares some of the characteristics of an Earth System Model of Intermediate complexity. We perform two experiments with this model to determine the potential effects of positive and negative feedbacks due to a dynamic hydrological cycle, and due to the relative distribution of trees and grasses, in regulating global mean temperature. In the first experiment, we vary the intensity of insolation on the model's surface both with and without an active (fully coupled) water cycle. In the second, we test the strength of feedbacks with biota in a fully coupled model by varying the optimal growing temperature for our two plant species (trees and grasses). We find that the negative feedbacks associated with the water cycle are far more powerful than those associated with the biota, but that the biota still play a significant role in shaping the model climate. third experiment, we vary the heat and moisture transport coefficient in an attempt to represent changing atmospheric circulations

Flavor-singlet light-cone amplitudes and radiative Upsilon decays in SCET

We study the evolution of flavor-singlet, light-cone amplitudes in the soft-collinear effective theory (SCET), and reproduce results previously obtained by a different approach. We apply our calculation to the color-singlet contribution to the photon endpoint in radiative Upsilon decay. In a previous paper, we studied the color-singlet contributions to the endpoint, but neglected operator mixing, arguing that it should be a numerically small effect. Nevertheless the mixing needs to be included in a consistent calculation, and we do just that in this work. We find that the effects of mixing are indeed numerically small. This result combined with previous work on the color-octet contribution and the photon fragmentation contribution provides a consistent theoretical treatment of the photon spectrum in radiative Upsilon decay.Comment: 19 pages with 8 figure

Water Distribution Modeling

To effectively use water distribution models, the engineer must be able to link knowledge of basic hydraulic theory and the mechanics of the program with that of the operation of real-world systems. Water Distribution Modeling does just that. Written by industry experts, it provides a practical resource for engineers and modelers that goes well beyond being a how-to guide for typing data into a computer program. It contains straightforward answers to common questions related both to modeling and to distribution systems in general. This textbook walks the practicing engineer or student through the modeling process from start to finish — from data collection and field-testing to using a model for system design and complex operational tasks

Probing partonic structure in gamma* gamma -> pi pi near threshold

Hadron pair production gamma* gamma -> h hbar in the region where the c.m. energy is much smaller than the photon virtuality can be described in a factorized form, as the convolution of a partonic handbag diagram and generalized distribution amplitudes which are new non-perturbative functions describing the exclusive fragmentation of a quark-antiquark pair into two hadrons. Scaling behavior and a selection rule on photon helicity are signatures of this mechanism. The case where h is a pion is emphasized.Comment: 8 pages, 1 figure, LaTeX2

Techniques for Improving Energy Efficiency at Water Supply Pumping Stations

This report describes the application of methods presented in Engineer Technical Letter (ETL) Energy Efficiency at Water Supply Pumping Stations\u27\u27 to the Washington, DC, and vicinity water system. Both the ETL and this report were prepared under the Water System Operation, Maintenance and Rehabilitation Work Unit (CWIS 31794) of the Water Supply and Conservation Research Program. The technical monitors for this program in the Office, Chief of Engineers, were Mr. James Ballif (DAEN-ECE-B) and Mr. Robert Daniel (DAEN-CWP-D). The work was conducted at the US Army Engineer (USAE) Waterways Experiment Station (WES), Vicksburg, Miss., and the University of Kentucky (UK) Civil Engineering Department. The report was written by Dr. Lindell E. Ormsbee, assistant professor of civil engineering at UK, working with WES under an Intergovernmental Personnel Act agreement; Dr. Thomas M. Walski, a research civil engineer with the Water Resources Engineering Group (WREG) of the Environmental Engineering Division (EED), Environmental Laboratory (EL), WES; and Messrs. Donald V. Chase and Wayne W. Sharp, UK students employed by WES under the contract student program. Mr. Anthony C. Gibson of the WREG assisted in field data collection. Work done with the Washington Aqueduct Division (WAD) of the USAE District, Baltimore, was performed under the purview of Mr. Harry C. Ways, Chief, WAD; Mr. Perry Costas, Assistant Chief, WAD; and Mr. Douglas B. Pickering, Chief, Plant Operations Branch, WAD. The report was reviewed by Mr. M. John Cullinane of the Water Supply and Waste Treatment Group, EED, and Dr. Keith W. Little of the Research Triangle Institute, Research Triangle Park, N.C. The report was edited by Ms. Jessica S. Ruff of the WES Information Technology Laboratory. The study was conducted under the supervision of Mr. F. Douglas Shields, Jr., Acting Chief, WREG; Dr. Raymond L. Montgomery, Chief, EED; and Dr. John Harrison, Chief, EL. Commander and Director of WES was Col. Dwayne G. Lee, CE. Technical Director was Dr. Robert W. Whalin

Time Management Strategies for Research Productivity

Researchers function in a complex environment and carry multiple role responsibilities. This environment is prone to various distractions that can derail productivity and decrease efficiency. Effective time management allows researchers to maintain focus on their work, contributing to research productivity. Thus, improving time management skills is essential to developing and sustaining a successful program of research. This article presents time management strategies addressing behaviors surrounding time assessment, planning, and monitoring. Herein, the Western Journal of Nursing Research editorial board recommends strategies to enhance time management, including setting realistic goals, prioritizing, and optimizing planning. Involving a team, problem-solving barriers, and early management of potential distractions can facilitate maintaining focus on a research program. Continually evaluating the effectiveness of time management strategies allows researchers to identify areas of improvement and recognize progress

Adapting to the digital age: a narrative approach

The article adopts a narrative inquiry approach to foreground informal learning and exposes a collection of stories from tutors about how they adapted comfortably to the digital age. We were concerned that despite substantial evidence that bringing about changes in pedagogic practices can be difficult, there is a gap in convincing approaches to help in this respect. In this context, this project takes a “bottom-up” approach and synthesises several life-stories into a single persuasive narrative to support the process of adapting to digital change. The project foregrounds the small, every-day motivating moments, cultural features and environmental factors in people's diverse lives which may have contributed to their positive dispositions towards change in relation to technology enhanced learning. We expect that such narrative approaches could serve to support colleagues in other institutions to warm up to ever-changing technological advances

A faster pseudo-primality test

We propose a pseudo-primality test using cyclic extensions of $\mathbb Z/n \mathbb Z$. For every positive integer $k \leq \log n$, this test achieves the security of $k$ Miller-Rabin tests at the cost of $k^{1/2+o(1)}$ Miller-Rabin tests.Comment: Published in Rendiconti del Circolo Matematico di Palermo Journal, Springe