Edge Designs Research Articles

Experimental Designs for Selecting Molecules from Large Chemical Databases

Recent developments in high-throughput screening and combinatorial chemistry have generated interest in experimental design methods to select subsets of molecules from large chemical databases. In this manuscript three methods for selecting molecules from large databases are described: edge designs, spread designs, and coverage designs. Two algorithms with linear time complexity that approximate spread and coverage designs are described. These algorithms can be threaded for multiprocessor systems, are compatible with any definition of molecular distance, and may be applied to very large chemical databases. For example, ten thousand molecules were selected using the maximum dissimilarity approximation to a spread design from a sixty-dimensional simulated molecular database of one million molecules in approximately 6 h on a UNIX workstation.

Screening by conference designs

Screening experiments aim to identify the relevant variables within some process potentially depending on a large number of variables. In this paper we introduce a new class of experimental designs called edge designs. These designs allow a model-independent estimate of the set of relevant variables, thus providing more robustness than traditional designs. We give a bound on the determinant of the information matrix of certain edge designs, and show that a large class of edge designs meeting this bound can be constructed from conference matrices. We also show that the resulting conference designs have an optimal space exploration property which guards against unexpected nonlinearities. We survey the existence of and constructions for conference matrices, and, for n < 50 variables, give explicit such matrices when n is a prime, and references to explicit constructions otherwise.

An Analysis of Edge Heat Transfer in Residential Windows

New window technologies are reducing heat transfer through the glazed areas of windows. Low-emissivity (low-E) coatings reduce radiative heat transfer and low-conductivity gas fills (which replace the air between glazing layers) reduce conductive heat transfer. Given these advantages in insulating glass technol ogy. researchers and manufacturers are now beginning to focus their attention on re ducing heat transfer through window edges. Old edge designs are now under scru tiny and new designs are being proposed.

Containment of a silicone fluid free surface in reduced gravity

In support of the Surface Tension Driven Convection Experiment planned for flight aboard the space shuttle, tests were conducted under reduced gravity in the 2.2-second drop tower and the 5.0-second Zero-G facility at the Lewis Research Center. The dynamics of controlling the test fluid, a 10-centi Stoke viscosity silicone fluid, in a low gravity environment were investigated using different container designs and barrier coatings. Three container edge designs were tested without a barrier coating: a square edge, a sharp edge with a 45-deg slope, and a saw-tooth edge. All three edge designs were successful in containing the fluid below the edge. G-jitter experiments were made in scaled-down containers subjected to horizontal accelerations. The data showed that a barrier coating is effective in containing silicone fluid under g-levels up to 10•1 g0.

Advanced Cooled Turbine Airfoil Aerodynamic Investigation

Abstract : Several connectively cooled trailing edge designs were investigated with the objective of eliminating the need for film cooling on the airfoil suction side. A 43.4% reduced solidity first stage turbine vane having potential application for an advanced Air Force fighter engine was selected for the evaluation. The final design eliminates film cooling on the suction side and uses the wavy criss-cross slot as the cooling scheme for the trailing edge section. The cooling design was incorporated into a cascade test airfoil using the radial wafer fabrication technique. The airfoil was constructed by photoetching the cooling design into the individual wafers, bonding the wafers together and machining the bonded block into the airfoil shape. The airfoil was subsequently evaluated in an airfoil cascade test to determine the aerodynamic and cooling performance. The aerodynamic profile loss of the reduced solidity radial wafer airfoil was reduced 56% relative to a baseline 43.4% reduced solidity configuration with film cooled suction surface and was 30% under the program goal. The wavy criss-cross slot design used in the trailing edge section proved to be an efficient cooling technique, and eliminated the need for suction side film cooling.

Post-operative capsular opacification

Post-operative capsular opacification (PCO) is a multifactorial physiological consequence of cataract surgery. Opacification involving the central posterior capsule has a significant impact on high and low contrast acuity and low contrast sensitivity. The assessment of PCO on cadaver eyes, experimental studies and culture models and in clinical studies has provided an understanding of its pathogenesis. The proliferation, migration and abnormal differentiation of residual lens epithelial cells and fibers in the capsular bag have been implicated in the pathogenesis of PCO. The incidence and severity of PCO correlates to the use of surgical techniques, intraocular lens (IOL) optic edge designs and IOL materials. This article summarizes the clinical studies with recommendations for retarding the development of central PCO. It discusses experiments with pharmacological agents broadly categorized as anti-inflammatory, immuno-modulating, antiproliferative, antiadhering and antitransdifferentiating agents for the prevention of PCO. These studies will remain critical for future endeavors undertaken for the eradication of PCO.