Low-speed aerodynamic characteristics of a 13.1-percent-thick, high-lift airfoil

Low speed sectional characteristics of a high lift airfoil are studied and a comparison is made of those characteristics with the predictions of the theoretical methods used in the airfoil's design. The 13.1 percent-thick, UI-1720 airfoil was found to achieve the predicted maximum lift coefficient of nearly 2.0. No upper-surface, flow separation was found below the stall angle of attack of 16 degrees; it appeared that stall was due to an abrupt leading edge flow separation

Segment-based Reliability/Supply Short Fall Analysis of Water Distribution Networks

AbstractPipe failure is a major parameter affecting the reliability of a water distribution network (WDN). A WDN consists of isolation valves which are closed to isolate a failed pipe for repairs. Depending up on the location of valves, a group of pipes termed as a segment gets isolated. Herein, reliability is estimated based on supply shortfall considering isolation of an appropriate segment on failure of a pipe. Supply shortfall is obtained using node flow analysis. An existing water main system is chosen as an example to compare the reliability values obtained by considering the actual location of valves and valves in each pipes on either end

Upgrading Reliability of Water Distribution Networks Recognizing Valve Locations

AbstractAn iterative procedure for upgrading water distribution network reliability is proposed by recognizing valve locations. In each iteration, three types of alternatives: (1) an addition of a valve(s) to pipe(s) without a valve; (2) an addition of a parallel pipe to an existing pipe; and (3) an increase in size of newly added pipes, are compared and the best is implemented. The iterative method is continued until no further improvement in reliability is possible, or a desired level of reliability is reached. This method is illustrated through an example taken from literature

Propeller study. Part 3: Experimental determination of thrust and torque on the YO-3A aircraft

Instrumentation and procedures for obtaining in-flight measurements of the torque and thrust of a propeller mounted on a YO-3A aircraft are described. Problems encountered in the study are discussed and methods for eliminating these difficulties are suggested

Bankfull Hydraulic Geometry Relationships for the Inner and Outer Bluegrass Regions of Kentucky

Bankfull hydraulic geometry relationships relate bankfull stream dimensions, such as cross-sectional area, width, mean depth, mean velocity, width to depth ratio, and slope to bankfull discharge. These relationships can assist in determining a design discharge for stream restoration and management projects. This study assessed 27 stable streams located in the Inner Bluegrass and Outer Bluegrass regions of Kentucky. Reaches were selected based on the presence of a U.S. Geological Survey gage, as well as other conditions such as presence of readily identifiable bankfull indicators, stability indices, and site accessibility. Bankfull channel dimensions and discharges were determined, and hydraulic geometry relationships were developed for both the Inner Bluegrass and Outer Bluegrass regions. These scaling relationships for karst-influenced streams were similar to others reported in the literature for non-karst areas. Significant differences between the regions were found only for bankfull width and width-to-depth ratio. Streams in the Inner Bluegrass tended to be more narrow and deep at bankfull discharges less than 10 m3s−1 and wider and shallower at bankfull discharges greater than 20 m3s−1 as compared to stream in the Outer Bluegrass. It is suspected that physiographic conditions related to local geology and/or riparian vegetation at three sites in the Outer Bluegrass accounted for these differences. Results of this study indicate that in instances of geologic variation within a physiographic region, hydraulic geometry relationships may require evaluation at the watershed scale

Reactive and responsive functionalized membranes

Surface functionalization of traditional NF, RO, and UF membranes to reduce fouling has been widely reported in the literature. On the other hand, pore functionalization of MF membranes through in-situ polymerization or attachment of macromolecules brings in new opportunities through pore conformation change and creation of high density active sites. These approaches dramatically enhance the applications of membranes in water and bio-nano field. The development of responsive, multifunctional materials and membranes for environmental applications requires a high level of control of both the characteristics of the base polymeric or inorganic support layer, as well as, its corresponding surface properties. Synthesis of membranes functionalized with appropriate macromolecules or reactive groups or enzymes and nano-catalytic particles can indeed provide applications ranging from tunable flux and separations, high-capacity metal capture, to toxic organic degradation by nanoparticles or enzymes. The use of macromolecules, such as, poly-acrylic acid (PAA), poly-glutamic acid (PLGA) provides pH responsive behavior pH modulations, whereas poly-N-isopropylacrylamide (pNIPAAm) provides temperature responsive behavior. The dependence of conformation properties of polyelectrolytes provides tunable separation and membrane flux control by pH or temperature based stimuli responsive properties. Layer-by-layer (LbL) assembly technique, most commonly conducted by intercalation of positive and negative polyelectrolytes or polypeptides, is a powerful, versatile and simple method for assembling supramolecular structures where enzymes or precise porin channels can be incorporated. The presentation will include: (1) synthesis and pore functionalization approaches, and direct polymerization of acrylic acid in membrane pores (lab-scale to full-scale), (2) pH and temperature responsive behavior, and catalytic nanoparticle synthesis in pores for environmentally important reductive and oxidative reactions, (3) pore functionalized (LbL approach) membranes for enzymatic (glucose oxidase and laccase), and environmentally important reactions,(4) porin channels for selective separations, (5) combination NF-Functionalized membrane process for practical applications in energy industries. The authors acknowledge the support of NSF KY EPSCoR program, NIH-NIEHS-SRC program, Southern services Co, Chevron Corporation, and Nanostone Membranes for full-scale membrane development work. The authors also acknowledge the highly significant research contributions of Drs. Li, Lewis, Ritchie, Hestekin, Meeks, and Gui

\u3cem\u3eWater Expert\u3c/em\u3e: A Conceptualized Framework for Development of a Rule-Based Decision Support System for Distribution System Decontamination

Significant drinking water contamination events pose a serious threat to public and environmental health. Water utilities often must make timely, critical decisions without evaluating all facets of the incident. The data needed to enact informed decisions are inevitably dispersant and disparate, originating from policy, science, and heuristic contributors. Water Expert is a functioning hybrid decision support system (DSS) and expert system framework that emphasizes the meshing of parallel data structures in order to expedite and optimize the decision pathway. Delivered as a thin-client application through the user\u27s web browser, Water Expert\u27s extensive knowledgebase is a product of inter-university collaboration that methodically pieced together system decontamination procedures. Decontamination procedures are investigated through consultation with subject matter experts, literature review, and prototyping with stakeholders. This paper discusses the development of Water Expert, analyzing the development process underlying the DSS and the system\u27s existing architecture specifications. Water Expert constitutes the first system to employ a combination of deterministic and heuristic models which provide decontamination solutions for water distribution systems. Results indicate that the decision making process following a contamination event is a multi-disciplinary effort. This contortion of multiple inputs and objectives limit the ability of the decision maker to find optimum solutions without technological intervention

Multiobjective optimization of water distribution systems accounting for economic cost, hydraulic reliability, and greenhouse gas emissions

In this paper, three objectives are considered for the optimization of water distribution systems (WDSs): the traditional objectives of minimizing economic cost and maximizing hydraulic reliability and the recently proposed objective of minimizing greenhouse gas (GHG) emissions. It is particularly important to include the GHG minimization objective for WDSs involving pumping into storages or water transmission systems (WTSs), as these systems are the main contributors of GHG emissions in the water industry. In order to better understand the nature of tradeoffs among these three objectives, the shape of the solution space and the location of the Pareto-optimal front in the solution space are investigated for WTSs and WDSs that include pumping into storages, and the implications of the interaction between the three objectives are explored from a practical design perspective. Through three case studies, it is found that the solution space is a U-shaped curve rather than a surface, as the tradeoffs among the three objectives are dominated by the hydraulic reliability objective. The Pareto-optimal front of real-world systems is often located at the "elbow" section and lower "arm" of the solution space (i.e., the U-shaped curve), indicating that it is more economic to increase the hydraulic reliability of these systems by increasing pipe capacity (i.e., pipe diameter) compared to increasing pumping power. Solutions having the same GHG emission level but different cost-reliability tradeoffs often exist. Therefore, the final decision needs to be made in conjunction with expert knowledge and the specific budget and reliability requirements of the system. © 2013. American Geophysical Union. All Rights Reserved.Wenyan Wu, Holger R. Maier, and Angus R. Simpso