Effect of Pressure in Thermoplastic Ribbon Thermal Welding

NASA Technical Reports Server (NTRS)

Hinkley, J. A.; Messier, B. C.; Marchello, J. M.

1996-01-01

An inexpensive apparatus was designed to simulate some features of on-the-fly thermal welding in heated-head tow placement. Previous studies have shown how ply/ply weld strength depends on weld time/temperature history. The apparatus has been modified recently to apply higher contact forces. Welding at pressures up to 1.7MPa (250psi) produced more consistent welds and fewer intra-ply voids, This has permitted a study of the conditions required for achieving the limiting ply/ply cohesive strength in simulated tow placement of a polyimide oligomer.

Structures, Design and Test: Materials

NASA Technical Reports Server (NTRS)

2004-01-01

NASA Marshall has developed a technology that combines a film/adhesive laydown module with fiber placement technology to enable the processing of composite prepreg tow/tape and films, foils, or adhesives on the same placement machine. The deve!opment of this technology grew out of NASA's need for lightweight, permeation-resistant cryogenic propellant tanks.

The Effect of Tow Shearing on Reinforcement Positional Fidelity in the Manufacture of a Continuous Fiber Reinforced Thermoplastic Matrix Composite via Pultrusion-Like Processing of Commingled Feedstock

NASA Astrophysics Data System (ADS)

Warlick, Kent M.

While the addition of short fiber to 3D printed articles has increased structural performance, ultimate gains will only be realized through the introduction of continuous reinforcement placed along pre-planned load paths. Most additive manufacturing research focusing on the addition of continuous reinforcement has revolved around utilization of a prefrabricated composite filament or a fiber and matrix mixed within a hot end prior to deposition on a printing surface such that conventional extrusion based FDM can be applied. Although stronger 3D printed parts can be made in this manner, high quality homogenous composites are not possible due to fiber dominated regions, matrix dominated regions, and voids present between adjacent filaments. Conventional composite manufacturing processes are much better at creating homogeneous composites; however, the layer by layer approach in which they are made is inhibiting the alignment of reinforcement with loads. Automated Fiber Placement techniques utilize in plane bending deformation of the tow to facilitate tow steering. Due to buckling fibers on the inner radius of curves, manufacturers recommend a minimum curvature for path placement with this technique. A method called continuous tow shearing has shown promise to enable the placement of tows in complex patterns without tow buckling, spreading, and separation inherent in conventional forms of automated reinforcement positioning. The current work employs fused deposition modeling hardware and the continuous tow shearing technique to manufacture high quality fiber reinforced composites with high positional fidelity, varying continuous reinforcement orientations within a layer, and plastic elements incorporated enabling the ultimate gains in structural performance possible. A mechanical system combining concepts of additive manufacturing with fiber placement via filament winding was developed. Paths with and without tension inherent in filament winding were analyzed through microscopy in order to examine best and worst case scenarios. High quality fiber reinforced composite materials, in terms of low void content, high fiber volume fractions and homogeneity in microstructure, were manufactured in both of these scenarios. In order to improve fidelity and quality in fiber path transition regions, a forced air cooling manifold was designed, printed, and implemented into the current system. To better understand the composite performance that results from varying pertinent manufacturing parameters, the effect of feed rate, hot end temperature, forced air cooling, and deposition surface (polypropylene and previously deposited glass polypropylene commingled tow) on interply performance, microstructure, and positional fidelity were analyzed. Interply performance, in terms of average maximum load and average peel strength, was quantified through a t-peel test of the bonding quality between two surfaces. With use of forced air cooling, minor decreases in average peel strength were present due to a reduction in tow deposition temperature which was found to be the variable most indicative of performance. Average maximum load was comparable between the forced air cooled and non-air cooled samples. Microstructure was evaluated through characterization of composite area, void content, and flash percentage. Low void contents mostly between five to seven percent were attained. Further reduction of this void content to two percent is possible through higher processing temperatures; however, reduced composite area, low average peel strength performance, and the presence of smoke during manufacturing implied thermal degradation of the polypropylene matrix occurred in these samples with higher processing temperatures. Positional fidelity was measured through calculations of shear angle, shift width, and error of a predefined path. While positional fidelity variation was low with a polypropylene deposition surface, forced air cooling is necessary to achieve fidelity on top of an already deposited tow surface as evident by the fifty-six percent reduction in error tolerance profile achieved. Lastly, proof of concept articles with unique fiber paths and neat plastic elements incorporated were produced to demonstrate fiber placement along pre-planned load paths and the ability to achieve greater structural efficiency through the use of less material. The results show that high positional fidelity and high quality composites can be produced through the use of the tow shearing technique implemented in the developed mechanical system. The implementation of forced air cooling was critical in achieving fidelity and quality in transition regions. Alignment of continuous reinforcement with pre-planned load paths was demonstrated in the proof of concept article with varying fiber orientations within a layer. Combining fused deposition modeling of plastic with the placement of continuous reinforcement enabled a honeycomb composite to be produced with higher specific properties than traditional composites. Thus, the current system demonstrated a greater capability of achieving ultimate gains in structural performance than previously possible.

Studies on Automated Manufacturing of High Performance Composites

NASA Technical Reports Server (NTRS)

Cano, R. J.; Belvin, H. L.; Hulcher, A. B.; Grenoble, R. W.

2001-01-01

The NASA Langley Research Center fiber placement facility has proven to be a valuable asset for obtaining data, experience, and insights into the automated fabrication of high performance composites. The facility consists of two automated devices: an Asea Brown Boveri (ABB) robotic arm with a modified heated head capable of hot gas and focused infrared heating and a 7' x 17' gantry containing a feeder head, rotating platform, focused infrared lamp and e-beam gun. While uncured thermoset tow and tape, e.g., epoxy and cyanate prepreg, can be placed with a robot, the placement facility s most powerful attribute is the ability to place thermoplastic and e-beam curable material to net shape. In recent years, ribbonizing techniques have been developed to make high quality thermoplastic and thermoset dry material forms to the standards required for robotic placement. A variety of composites have been fabricated from these ribbons by heated head tow and tape placement including both flat plates and cylinders. Composite mechanical property values of the former were between 85 and 100 percent of those obtained by hand lay-up/autoclave processing.

Optimization of Elastically Tailored Tow-Placed Plates with Holes

NASA Technical Reports Server (NTRS)

Jegley, Dawn C.; Tatting, Brian F.; Guerdal, Zafer

2003-01-01

Elastic stiffness tailoring of laminated composite panels by allowing the fibers to curve within the plane of the laminate is a design concept that has been demonstrated to be both beneficial and practical. The objective of the present paper is to demonstrate the effectiveness of stiffness tailoring through the use of curvilinear fibers to reduce stress concentrations around the hole and improve the load carrying capability of panels. Preliminary panel designs that are to be manufactured and tested were determined through design studies for flat plates without holes under axial compression using an optimization program. These candidate designs were then analyzed with finite element models that accurately reflect the test conditions and geometries in order to decide upon the final designs for manufacture and testing. An advanced tow-placement machine is used to manufacture the test panels with varying fiber orientation angles. A total of six large panels measuring three feet by six feet, each of which is used to produce four specimens with or without holes, are fabricated. The panels were machined into specimens with holes and tested at NASA Langley Research Center. Buckling response and failure of panels without holes and with two different hole dimensions are presented. Buckling and failure loads of tow-steered specimens are significantly greater than the buckling and failure loads of traditional straight-fiber specimens.

Response of automated tow placed laminates to stress concentrations

NASA Technical Reports Server (NTRS)

Cairns, Douglas S.; Ilcewicz, Larry B.; Walker, Tom

1993-01-01

In this study, the response of laminates with stress concentrations is explored. Automated Tow Placed (ATP, also known as Fiber Placement) laminates are compared to conventional tape layup manufacturing. Previous tensile fracture tests on fiber placed laminates show an improvement in tensile fracture of large notches over 20 percent compared to tape layup laminates. A hierarchial modeling scheme is presented. In this scheme, a global model is developed for laminates with notches. A local model is developed to study the influence of inhomogeneities at the notch tip, which are a consequence of the fiber placement manufacturing technique. In addition, a stacked membrane model was developed to study delaminations and splitting on a ply-by-ply basis. The results indicate that some benefit with respect to tensile fracture (up to 11 percent) can be gained from inhomogeneity alone, but that the most improvement may be obtained with splitting and delaminations which are more severe in the case of fiber placement compared to tape layup. Improvements up to 36 percent were found from the model for fiber placed laminates with damage at the notch tip compared to conventional tape layup.

Reduced toxicity polyester resins and microvascular pre-preg tapes for advanced composites manufacturing

NASA Astrophysics Data System (ADS)

Poillucci, Richard

Advanced composites manufacturing broadly encapsulates topics ranging from matrix chemistries to automated machines that lay-up fiber-reinforced materials. Environmental regulations are stimulating research to reduce matrix resin formulation toxicity. At present, composites fabricated with polyester resins expose workers to the risk of contact with and inhalation of styrene monomer, which is a potential carcinogen, neurotoxin, and respiratory irritant. The first primary goal of this thesis is to reduce the toxicity associated with polyester resins by: (1) identification of potential monomers to replace styrene, (2) determination of monomer solubility within the polyester, and (3) investigation of approaches to rapidly screen a large resin composition parameter space. Monomers are identified based on their ability to react with polyester and their toxicity as determined by the Globally Harmonized System (GHS) and a green screen method. Solubilities were determined by the Hoftyzer -- Van Krevelen method, Hansen solubility parameter database, and experimental mixing of monomers. A combinatorial microfluidic mixing device is designed and tested to obtain distinct resin compositions from two input chemistries. The push for safer materials is complemented by a thrust for multifunctional composites. The second primary goal of this thesis is to design and implement the manufacture of sacrificial fiber materials suitable for use in automated fiber placement of microvascaular multifunctional composites. Two key advancements are required to achieve this goal: (1) development of a roll-to-roll method to place sacrificial fibers onto carbon fiber pre-preg tape; and (2) demonstration of feasible manufacture of microvascular carbon fiber plates with automated fiber placement. An automated method for placing sacrificial fibers onto carbon fiber tapes is designed and a prototype implemented. Carbon fiber tows with manual placement of sacrificial fibers is implemented within an automated fiber placement machine and the successful fabrication of a carbon fiber plate with an integrated microvascular channel is demonstrated.

Congenital diaphragmatic hernia in neonate: a retrospective study about 28 observations.

PubMed

Khemakhem, Rachid; Haggui, Basma; Rahay, Houda; Nouira, Faouzi; Charieg, Awatef; Ghorbel, Sofiane; Trifa, Mahdi; Jlidi, Said; Khalifa, Sonia Ben; Chaouachi, Beji

2012-01-01

Our purpose was to review our experience with congenital diaphragmatic hernia emphasizing diagnosis, management, and outcome. We conducted a retrospective review of all cases of babies with congenital diaphragmatic hernia diagnosed and treated in our centre from 1998 to 2010. There were 28 congenital diaphragmatic hernia cases, 13 girls and 15 boys with a mean weight birth of 3 kg. Three patients (10, 6% of cases) died within a few hours after admission. In the remaining cases, surgery was performed after a stabilization period of 2 days. The diaphragmatic defect was sitting in the posterolateral left in 23 cases and right in 2 cases. Its dimensions were on average 4,5 cm, tow cases of agenesis of the cupola were seen and required the placement of gortex prosthesis. The remaining cases are treated by direct closure of defect. Postoperative course was marked by an early death in context of respiratory distress in six cases and later with sepsis in tow cases. The outcome was favourable in 17 cases (60, 7%), despite the occurrence of sepsis in four cases and evisceration in two cases. Congenital diaphragmatic hernia remains a serious disease with high mortality and morbidity despite advances in prenatal diagnosis and neonatal resuscitation.

Measurement of Sub Degree Angular Carbon Fiber Tow Misalignment

NASA Technical Reports Server (NTRS)

Wilson, William C.; Moore, Jason P.; McCraw, Hunter

2017-01-01

NASA is investigating the use of carbon fiber tow steering to tune aeroelastic characteristics in advanced composite structures. In support of that effort, NASA is also investigating methods of measuring the angle of carbon fiber tows as they are placed. This work presents the results of using microwave reflectometry in the approximately 2 GHz region to measure carbon fiber tow angles at 0.1deg resolution.

An Experimental Study of the Influence of in-Plane Fiber Waviness on Unidirectional Laminates Tensile Properties

NASA Astrophysics Data System (ADS)

Zhao, Cong; Xiao, Jun; Li, Yong; Chu, Qiyi; Xu, Ting; Wang, Bendong

2017-12-01

As one of the most common process induced defects of automated fiber placement, in-plane fiber waviness and its influences on mechanical properties of fiber reinforced composite lack experimental studies. In this paper, a new approach to prepare the test specimen with in-plane fiber waviness is proposed in consideration of the mismatch between the current test standard and actual fiber trajectory. Based on the generation mechanism of in-plane fiber waviness during automated fiber placement, the magnitude of in-plane fiber waviness is characterized by axial compressive strain of prepreg tow. The elastic constants and tensile strength of unidirectional laminates with in-plane fiber waviness are calculated by off-axis and maximum stress theory. Experimental results show that the tensile properties infade dramatically with increasing magnitude of the waviness, in good agreement with theoretical analyses. When prepreg tow compressive strain reaches 1.2%, the longitudinal tensile modulus and strength of unidirectional laminate decreased by 25.5% and 57.7%, respectively.

Composite fuselage crown panel manufacturing technology

NASA Technical Reports Server (NTRS)

Willden, Kurtis; Metschan, S.; Grant, C.; Brown, T.

1992-01-01

Commercial fuselage structures contain significant challenges in attempting to save manufacturing costs with advanced composite technology. Assembly issues, materials costs, and fabrication of elements with complex geometry are each expected to drive the cost of composite fuselage structure. Key technologies, such as large crown panel fabrication, were pursued for low cost. An intricate bond panel design and manufacturing concept were selected based on the efforts of the Design Build Team. The manufacturing processes selected for the intricate bond design include multiple large panel fabrication with Advanced Tow Placement (ATP) process, innovative cure tooling concepts, resin transfer molding of long fuselage frames, and use of low cost materials forms. The process optimization for final design/manufacturing configuration included factory simulations and hardware demonstrations. These efforts and other optimization tasks were instrumental in reducing costs by 18 pct. and weight by 45 pct. relative to an aluminum baseline. The qualitative and quantitative results of the manufacturing demonstrations were used to assess manufacturing risks and technology readiness.

Composite fuselage crown panel manufacturing technology

NASA Technical Reports Server (NTRS)

Willden, Kurtis; Metschan, S.; Grant, C.; Brown, T.

1992-01-01

Commercial fuselage structures contain significant challenges in attempting to save manufacturing costs with advanced composite technology. Assembly issues, material costs, and fabrication of elements with complex geometry are each expected to drive the cost of composite fuselage structures. Boeing's efforts under the NASA ACT program have pursued key technologies for low-cost, large crown panel fabrication. An intricate bond panel design and manufacturing concepts were selected based on the efforts of the Design Build Team (DBT). The manufacturing processes selected for the intricate bond design include multiple large panel fabrication with the Advanced Tow Placement (ATP) process, innovative cure tooling concepts, resin transfer molding of long fuselage frames, and utilization of low-cost material forms. The process optimization for final design/manufacturing configuration included factory simulations and hardware demonstrations. These efforts and other optimization tasks were instrumental in reducing cost by 18 percent and weight by 45 percent relative to an aluminum baseline. The qualitative and quantitative results of the manufacturing demonstrations were used to assess manufacturing risks and technology readiness.

Carbon Fiber TOW Angle Determination Using Microwave Reflectometry

NASA Technical Reports Server (NTRS)

Wilson, William C.; Moore, Jason P.; Juarez, Peter D.

2016-01-01

NASA's Advanced Composites Project is investigating technologies that increase automated remote inspection of aircraft composite structures. Therefore, microwave Frequency Domain Reflectometry (FDR) is being investigated as a method of enabling rapid remote inspection of angular orientation of the tow using microwave radiation. This work will present preliminary data demonstrating that frequency shifts in the reflection spectrum of a carbon fiber tow sample are indicative of the angle of the tow with respect to an interrogating antenna's linear polarized output.

82 FR 38764 - Wassenaar Arrangement 2016 Plenary Agreements Implementation

Federal Register 2010, 2011, 2012, 2013, 2014

2017-08-15

... `ceramic-``matrix'',' so as to control carbon fiber reinforced SiC matrix composites (C-SiC). These... Machines and Tow/Fiber Placement machines were accurately delineated at 1 inch, which is used in industry... manufacturing process. The formerly used phrase ``incorporating particles, whiskers or fibers'' did not...

One-Dimensional Model for the Ultrasonic Response of Resin-Filled Gaps in Automated Tape Layup Composites

NASA Technical Reports Server (NTRS)

Johnston, Patrick H.; Juarez, Peter D.

2017-01-01

Automated tow placement has become a widely used fabrication technique, especially for large aerospace structures. Robotic heads lay down strips (tows) of preimpregnated fiber along programmed paths. The intention is to lay adjacent tows abutted to one another, but sometimes a gap is left between a tow and the previously-placed tow. If a tow gap exists, it fills with resin during cure, forming a fiber-free volume. In immersion ultrasonic pulse-echo measurements of a cured laminate, the gap can be observed to produce a noticeable echo, without significantly attenuating the back-wall reflection of the laminate. To understand this behavior, we considered a one dimensional model of the composite laminate, with a thin layer having the ultrasonic sound speed and density of neat resin, sandwiched between two layers of material having the sound speed and density of fiber-reinforced composite and surrounded on both sides by water. Neglecting attenuation, we considered the transmission and reflection coefficients of each interface, as well as that of the thin resin layer. Using the initial water/composite reflection as a reference, we computed the relative magnitude of the back surface/water reflection in the presence and in the absence of a resin-only layer, as well as the relative magnitude of the reflection arising from a thin resin layer in composite. While the one-dimensional model did not fully match the measurements, it did qualitatively explain the observed behavior.

Test results from large wing and fuselage panels

NASA Technical Reports Server (NTRS)

Madan, Ram C.; Voldman, Mike

1993-01-01

This paper presents the first results in an assessment of the strength, stiffness, and damage tolerance of stiffened wing and fuselage subcomponents. Under this NASA funded program, 10 large wing and fuselage panels, variously fabricated by automated tow placement and dry-stitched preform/resin transfer molding, are to be tested. The first test of an automated tow placement six-longeron fuselage panel under shear load was completed successfully. Using NASTRAN finite-element analysis the stiffness of the panel in the linear range prior to buckling was predicted within 3.5 percent. A nonlinear analysis predicted the buckling load within 10 percent and final failure load within 6 percent. The first test of a resin transfer molding six-stringer wing panel under compression was also completed. The panel failed unexpectedly in buckling because of inadequate supporting structure. The average strain was 0.43 percent with a line load of 20.3 kips per inch of width. This strain still exceeds the design allowable strains. Also, the stringers did not debond before failure, which is in contrast to the general behavior of unstitched panels.

Automated Tow Placed LaRC(TM)-PETI-5 Composites

NASA Technical Reports Server (NTRS)

Hou, T. H.; Belvin, H. L.; Johnston, N. J.

2001-01-01

LaRC(TM)-PETI-5 is a PhenylEthynyl-Terminated Imide resin developed at NASA Langley Research Center (LaRC) during the 1990s. It offers a combination of attractive composite and adhesive properties. IM7/LaRC(TM)-PETI-5 composites exhibit thermal and thermo-oxidative stability typical of polyimides, superior chemical resistance and processability, excellent mechanical properties, toughness and damage tolerance. It was selected for study in the High Speed Research program aimed at developing technologies for a future supersonic aircraft, the High Speed Civil Transport, with a projected life span of 60 000 h at a cruise speed up to Mach 2.4. Robust autoclave processing cycles for LaRC(TM)-PETI-5 composites have been thoroughly designed and demonstrated, which involved hand lay-up of solvent-ladened 'wet' prepregs. However, this type of processing is not only costly but also environmentally unfriendly. Volatile management and shrinkage could become serious problems in the fabrication of large complex airframe structural subcomponents. Robotic tow placement technology utilizing 'dry' material forms represents a new fabrication process which overcomes these deficiencies. This work evaluates and compares mechanical properties of composites fabricated by heated head automated tow placement (dry process) with those obtained by hand lay-up/autoclave fabrication (wet process). Thermal and rheological properties of the robotically as-placed uncured composites were measured. A post-cure cycle was designed due to the requirement of the PETI-5 resin for a 370 C/1 h hold to reach full cure, conditions which cannot be duplicated during heated head robotic placement. Mechanical properties such as 0 degree flexural strength and modulus, open hole tensile and compressive strength and moduli, reduced section compression dogbone compressive strength, and modified zippora-medium small (MZ-MS) tensile and compressive properties were obtained on the post-cured panels. These properties compared favourably with those obtained from the wet process.

Imperfection Insensitivity Analyses of Advanced Composite Tow-Steered Shells

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey; Farrokh, Babak; Stanford, Bret K.; Weaver, Paul M.

2016-01-01

Two advanced composite tow-steered shells, one with tow overlaps and another without overlaps, were previously designed, fabricated and tested in end compression, both without cutouts, and with small and large cutouts. In each case, good agreement was observed between experimental buckling loads and supporting linear bifurcation buckling analyses. However, previous buckling tests and analyses have shown historically poor correlation, perhaps due to the presence of geometric imperfections that serve as failure initiators. For the tow-steered shells, their circumferential variation in axial stiffness may have suppressed this sensitivity to imperfections, leading to the agreement noted between tests and analyses. To investigate this further, a numerical investigation was performed in this study using geometric imperfections measured from both shells. Finite element models of both shells were analyzed first without, and then, with measured imperfections that were then, superposed in different orientations around the shell longitudinal axis. Small variations in both the axial prebuckling stiffness and global buckling load were observed for the range of imperfections studied here, which suggests that the tow steering, and resulting circumferentially varying axial stiffness, may result in the test-analysis correlation observed for these shells.

Optimal Composite Material for Low Cost Fabrication of Large Composite Aerospace Structures using NASA Resins or POSS Nanoparticle Modifications

NASA Technical Reports Server (NTRS)

Lamontia, Mark A.; Gruber, Mark B.; Jensen, Brian J.

2006-01-01

Thermoplastic laminates in situ consolidated via tape or tow placement require full mechanical properties. Realizing full properties requires resin crystallinity to be controlled - partial crystallinity leads to unacceptably low laminate compression properties. There are two approaches: utilize an amorphous matrix resin; or place material made from a semi-crystalline resin featuring kinetics faster than the process. In this paper, a matrix resin evaluation and trade study was completed with commercial and NASA amorphous polyimides on the one hand, and with PEKK mixed with POSS nanoparticles for accelerated crystallinity growth on the other. A new thermoplastic impregnated material, 6 mm wide (0.25-in) AS-4 carbon/LaRC(TradeMark)8515 dry polyimide tow, was fabricated. Since LaRC(TradeMark)8515 is fully amorphous, it attains full properties following in situ consolidation, with no post processing required to build crystallinity. The tow in situ processing was demonstrated via in situ thermoplastic filament winding it into rings.

Design and Manufacture of Elastically Tailored Tow Placed Plates

NASA Technical Reports Server (NTRS)

Tatting, Brain F.; Guerdal, Zafer; Jegley, Dawn (Technical Monitor)

2002-01-01

Elastic stiffness tailoring of laminated composite panels by allowing the fibers to curve within the plane of the laminate is a relatively novel design concept that has been demonstrated to be both beneficial and practical. In particular, for structures with highly non-uniform stress states, such as the case of a flat panel with a central hole subjected to in-plane loading, the concept is likely to provide substantial improvements in load carrying capability. The objective of the present study is to determine the effectiveness of stiffness tailoring through the use of curvilinear fibers to reduce stress concentrations around the hole and improve the load carrying capability of panels with holes. In this study software was created that translates standard finite element models with traditional laminate definitions into ones that possess stacking sequences with curvilinear fiber paths that are directly manufacturable using an advanced tow placement machine. Preliminary designs for the manufacturing and testing phase were determined through rudimentary design studies for flat plates without holes under axial compression. These candidate designs were then analyzed using finite element models that accurately reflect the test conditions and geometries in order to select final designs for testing. A total of six large panels, measuring three feet by six feet, each of which are used to produce four specimens with or without holes, were fabricated and delivered to NASA for machining and testing.

Cost studies for commercial fuselage crown designs

NASA Technical Reports Server (NTRS)

Walker, T. H.; Smith, P. J.; Truslove, G.; Willden, K. S.; Metschan, S. L.; Pfahl, C. L.

1991-01-01

Studies were conducted to evaluate the cost and weight potential of advanced composite design concepts in the crown region of a commercial transport. Two designs from each of three design families were developed using an integrated design-build team. A range of design concepts and manufacturing processes were included to allow isolation and comparison of cost centers. Detailed manufacturing/assembly plans were developed as the basis for cost estimates. Each of the six designs was found to have advantages over the 1995 aluminum benchmark in cost and weight trade studies. Large quadrant panels and cobonded frames were found to save significant assembly labor costs. Comparisons of high- and intermediate-performance fiber systems were made for skin and stringer applications. Advanced tow placement was found to be an efficient process for skin lay up. Further analysis revealed attractive processes for stringers and frames. Optimized designs were informally developed for each design family, combining the most attractive concepts and processes within that family. A single optimized design was selected as the most promising, and the potential for further optimization was estimated. Technical issues and barriers were identified.

Fabrication Of Carbon-Boron Reinforced Dry Polymer Matrix Composite Tape

NASA Technical Reports Server (NTRS)

Belvin, Harry L.; Cano, Roberto J.; Treasure, Monte; Shahood, Thomas W.

1999-01-01

Future generation aerospace vehicles will require specialized hybrid material forms for component structure fabrication. For this reason, high temperature composite prepregs in both dry and wet forms are being developed at NASA Langley Research Center (LaRC). In an attempt to improve compressive properties of carbon fiber reinforced composites, a hybrid carbon-boron tape was developed and used to fabricate composite laminates which were subsequently cut into flexural and compression specimens and tested. The hybrid material, given the designation HYCARB, was fabricated by modifying a previously developed process for the manufacture of dry polymer matrix composite (PMC) tape at LaRC. In this work, boron fibers were processed with IM7/LaRC(TradeMark)IAX poly(amide acid) solution-coated prepreg to form a dry hybrid tape for Automated Tow Placement (ATP). Boron fibers were encapsulated between two (2) layers of reduced volatile, low fiber areal weight poly(amide acid) solution-coated prepreg. The hybrid prepreg was then fully imidized and consolidated into a dry tape suitable for ATP. The fabrication of a hybrid boron material form for tow placement aids in the reduction of the overall manufacturing cost of boron reinforced composites, while realizing the improved compression strengths. Composite specimens were press-molded from the hybrid material and exhibited excellent mechanical properties.

Textile composite fuselage structures development

NASA Technical Reports Server (NTRS)

Jackson, Anthony C.; Barrie, Ronald E.; Chu, Robert L.

1993-01-01

Phase 2 of the NASA ACT Contract (NAS1-18888), Advanced Composite Structural Concepts and Materials Technology for Transport Aircraft Structures, focuses on textile technology, with resin transfer molding or powder coated tows. The use of textiles has the potential for improving damage tolerance, reducing cost and saving weight. This program investigates resin transfer molding (RTM), as a maturing technology for high fiber volume primary structures and powder coated tows as an emerging technology with a high potential for significant cost savings and superior structural properties. Powder coated tow technology has promise for significantly improving the processibility of high temperature resins such as polyimides.

Modeling Geometry and Progressive Failure of Material Interfaces in Plain Weave Composites

NASA Technical Reports Server (NTRS)

Hsu, Su-Yuen; Cheng, Ron-Bin

2010-01-01

A procedure combining a geometrically nonlinear, explicit-dynamics contact analysis, computer aided design techniques, and elasticity-based mesh adjustment is proposed to efficiently generate realistic finite element models for meso-mechanical analysis of progressive failure in textile composites. In the procedure, the geometry of fiber tows is obtained by imposing a fictitious expansion on the tows. Meshes resulting from the procedure are conformal with the computed tow-tow and tow-matrix interfaces but are incongruent at the interfaces. The mesh interfaces are treated as cohesive contact surfaces not only to resolve the incongruence but also to simulate progressive failure. The method is employed to simulate debonding at the material interfaces in a ceramic-matrix plain weave composite with matrix porosity and in a polymeric matrix plain weave composite without matrix porosity, both subject to uniaxial cyclic loading. The numerical results indicate progression of the interfacial damage during every loading and reverse loading event in a constant strain amplitude cyclic process. However, the composites show different patterns of damage advancement.

Payment of Advanced Placement Exam Fees by Virginia Public School Divisions and Its Impact on Advanced Placement Enrollment and Scores

ERIC Educational Resources Information Center

Cirillo, Mary Grupe

2010-01-01

The purpose of this study was to determine the impact of Virginia school divisions' policy of paying the fee for students to take Advanced Placement exams on Advanced Placement course enrollment, the number of Advanced Placement exams taken by students, the average scores earned and the percent of students earning qualifying scores of 3, 4, or 5…

Materials and Area of Study for Advanced Placement Program in American History.

ERIC Educational Resources Information Center

Santos, Peter A.

This paper describes and evaluates benefits of advanced placement programs and identifies materials which can help high school history classroom teachers develop effective advanced placement programs. An advanced placement program is defined as a program which requires a student to do extensive research and writing throughout the school year.…

Automated fiber placement composite manufacturing: The mission at MSFC's Productivity Enhancement Complex

NASA Technical Reports Server (NTRS)

Vickers, John H.; Pelham, Larry I.

1993-01-01

Automated fiber placement is a manufacturing process used for producing complex composite structures. It is a notable leap to the state-of-the-art in technology for automated composite manufacturing. The fiber placement capability was established at the Marshall Space Flight Center's (MSFC) Productivity Enhancement Complex in 1992 in collaboration with Thiokol Corporation to provide materials and processes research and development, and to fabricate components for many of the Center's Programs. The Fiber Placement System (FPX) was developed as a distinct solution to problems inherent to other automated composite manufacturing systems. This equipment provides unique capabilities to build composite parts in complex 3-D shapes with concave and other asymmetrical configurations. Components with complex geometries and localized reinforcements usually require labor intensive efforts resulting in expensive, less reproducible components; the fiber placement system has the features necessary to overcome these conditions. The mechanical systems of the equipment have the motion characteristics of a filament winder and the fiber lay-up attributes of a tape laying machine, with the additional capabilities of differential tow payout speeds, compaction and cut-restart to selectively place the correct number of fibers where the design dictates. This capability will produce a repeatable process resulting in lower cost and improved quality and reliability.

Standardized UXO Technology Demonstration Site Scoring Record No. 931 Technology Type/Platform: Magnetometer MTADS/Towed

DTIC Science & Technology

2009-07-01

of the 2 acre site was cleared of all metallic items. This clearing of the metallic anomalies from the 2 acre Active Response Demonstration Site... metallic items. Once the NRL MTADS surveyed the site, ATC collected their data and conducted another intrusive operation in order to remove any additional...anomalies. During each clearance operation, the exact placement of all the metallic items was carefully measured in order to create a GT for each

Advanced Placement Environmental Science and the Curriculum and Community Enterprise for Restoration Science (CCERS) Project in the New York City High School

ERIC Educational Resources Information Center

Birney, Lauren; McNamara, Denise

2018-01-01

This paper explores the issue of social justice through the lens of equitable access to Advanced Placement courses in the City of New York High Schools, with focus on Advanced Placement Environmental Science. A critical component of the Advanced Placement Environmental Science course is the incorporation of environmental fieldwork. The National…

The Under-Utilization and Problems Associated with the Advanced Placement Program of Adult High School Students

ERIC Educational Resources Information Center

Barham, Mary Ann

2009-01-01

The purpose of this study was to investigate the low participation rate among high school students 18 years of age or older in Advanced Placement courses. The subjects in this study were 129 Advanced Placement Students and 129 non-Advanced Placement high school students 18 years of age or older in five high schools in two Louisiana parishes.…

Four Decades of the Advanced Placement Program.

ERIC Educational Resources Information Center

Rothschild, Eric

1999-01-01

Reports on the history of the Advanced Placement (AP) program, considering such issues as the program's initiation, changes within the program, its various problems, growth in Advanced Placement, and the program's reach overseas. (CMK)

Intra-Inversion Filtering for Use of Magnetic Fields to Locate and Characterize Magnetic Dipoles for Unexploded Ordnance (UXO) Cleanup

DTIC Science & Technology

2007-02-26

IIGE Intra-Inversion Gradient Estimation JPG Jefferson Proving Ground (Indiana); www.jpgbrac.com MTADS Multi- sensor Towed Array Detection...wherein the Statement of Need sought development of algorithms to exploit data from current state-of-the-art geophysical sensors and advanced sensors ...profile direction using an array of magnetometers as in the Multi- sensor Towed Array Detection System (MTADS). In most instances, such data may be

An Examination of Perceptions Associated with Enrollment Procedures and Students Placement in Advanced Placement Courses in Northeast Louisiana

ERIC Educational Resources Information Center

Vidrine, Brent

2013-01-01

The purpose of the study was to investigate participation rates of minorities and economically disadvantaged students in Advanced Placement programs in selected high schools in Northeast Louisiana. Advanced Placement programs in high schools generally promote higher level education courses. The focus of the investigation was perceptions held by…

Accuracy and Safety of External Ventricular Drain Placement by Physician Assistants and Nurse Practitioners in Aneurysmal Acute Subarachnoid Hemorrhage.

PubMed

Enriquez-Marulanda, Alejandro; Ascanio, Luis C; Salem, Mohamed M; Maragkos, Georgios A; Jhun, Ray; Alturki, Abdulrahman Y; Moore, Justin M; Ogilvy, Christopher S; Thomas, Ajith J

2018-06-11

In the current dynamic health environment, increasing number of procedures are being completed by advanced practitioners (nurse practitioners and physician assistants). This is the first study to assess the clinical outcomes and safety of external ventricular drain (EVD) placements by specially trained advanced practitioners. Compare the safety and outcomes of EVD placement by advanced practitioners in patients with subarachnoid hemorrhage (SAH). A cohort comparison study was performed from an aneurysmal SAH database selecting patients treated with EVD from a single major academic institution in the USA between June 2007 and June 2017. Safety, accuracy, and complications of EVD placement were compared between advanced practitioners and neurosurgical physicians (attending neurosurgeon and subspecialty clinical fellow). Statistical analysis was performed using the Mann-Whitney test for continuous variables and χ 2 test for categorical variables, with p values set at < 0.05 for significance. We identified 203 patients for this cohort with 238 EVD placements; eighty-seven (36.6%) placements were performed by advanced practitioners and 151 (63.4%) by neurosurgeons. Most of the ventriculostomies were placed in the emergency room (n = 114; 47.9%). Additional procedures performed concurrently with the EVD placements were significantly higher among the physicians' group (21.8 vs. 4.6%; p < 0.001). Bedside placement and usage of Ghajar guide were significantly higher among advanced practitioner's (58.3 vs. 98.9 and 9.9 vs. 64.4%, respectively, with a p < 0.001 for both). There were, however, no significant differences in terms of the number of attempts for insertion, intraprocedural complications, tract hemorrhages, accuracy, infection rates, catheter dislodgments, and need for repositioning/replacement of EVD. After appropriate training, EVD placement can be safely performed by advanced practitioners with an adequate accuracy of placement.

78 FR 19691 - Applications for New Awards; Advanced Placement (AP) Test Fee Program

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-02

... DEPARTMENT OF EDUCATION Applications for New Awards; Advanced Placement (AP) Test Fee Program... Information Advanced Placement Test Fee Program. Notice inviting applications for new awards for fiscal year... Program: The AP Test Fee program awards grants to eligible State educational agencies (SEAs) to enable...

77 FR 8848 - Application for New Awards; Advanced Placement (AP) Test Fee Program

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-15

... DEPARTMENT OF EDUCATION Application for New Awards; Advanced Placement (AP) Test Fee Program... Information: Advanced Placement Test Fee Program. Notice inviting applications for new awards for fiscal year... Description Purpose of Program: The AP Test Fee program awards grants to eligible State educational agencies...

AP: A Critical Examination of the Advanced Placement Program

ERIC Educational Resources Information Center

Sadler, Philip M.; Sonnert, Gerhard; Tai, Robert; Klopfenstein, Kirstin

2016-01-01

The Advanced Placement (AP) program was created to enhance the experience of gifted students as they transition from high school to college. "AP: A Critical Examination of the Advanced Placement Program," edited by Philip M. Sadler, Gerhard Sonnert, Robert Tai, and Kirstin Klopfenstein (2010, Harvard Education Press), questions the…

Advanced Placement Academy: Case Study of a Program within a School

ERIC Educational Resources Information Center

Swanson, Julie Dingle; Nagy, Steven

2014-01-01

The focus of this study was the first year of implementation of the Advanced Placement Academy (APA), a program within a high school providing honors and Advanced Placement coursework for high-ability African American students with previously limited access to rigorous courses. The qualitative investigation explores practical solutions from…

Advanced Placement Course Description: Government and Politics, American Comparative: May 1987-May 1988.

ERIC Educational Resources Information Center

College Entrance Examination Board, Princeton, NJ.

The Advanced Placement Program is based on the premise that young people can complete college-level studies while in secondary schools. It is an instrument of cooperation that extends the educational opportunities available to students by giving secondary school college-level courses appropriate college credit and placement. Advanced Placement…

Advanced Placement U.S. History: What Happens after the Examination?

ERIC Educational Resources Information Center

Henry, Michael

1991-01-01

Discusses a survey of 56 advanced placement (AP) U.S. history teachers. Explores the scope of AP history and types of posttest activities used after Advanced Placement examinations. Concludes that public school courses developed more deeply into post-1960 events than the private schools did. Describes movies, debates, simulations, and local…

Using Distance Learning to Impact Access of Diverse Learners to Advanced Placement Programs

ERIC Educational Resources Information Center

Fenty, Nicole S.; Allio, Andrea

2017-01-01

Distance learning has been used as one method to increase access for students who have otherwise been underrepresented in college preparatory courses like Advanced Placement (AP). This study evaluated the impact of a statewide Virtual Advanced Placement (VAP) program on access to AP courses for students from underrepresented populations. Survey…

Progress in Advanced Placement and International Baccalaureate in SREB States. Challenge to Lead

ERIC Educational Resources Information Center

Kaye, Rebecca Daugherty

2006-01-01

Southern Regional Education Board (SREB) states lead the nation in student participation in Advanced Placement and International Baccalaureate Programs. SREB states know that getting students engaged in a challenging high school curriculum is the most important step they can take to promote college readiness. Advanced Placement (AP) courses and…

The Design and Synthesis of Epoxy Matrix Composites Curable by Electron Beam Induced Cationic Polymerization

NASA Technical Reports Server (NTRS)

Crivello, James V.

2000-01-01

Several new series of novel, high reactivity epoxy resins are described which are designed specifically for the fabrication of high performance carbon fiber reinforced composites for commercial aircraft structural applications using cationic UV and e-beam curing. The objective of this investigation is to provide resin matrices which rapidly and efficiently cure under low e-beam doses which are suitable to high speed automated composite fabrication techniques such as automated tape and tow placement. It was further the objective of this work to provide resins with superior thermal, oxidative and atomic oxygen resistance.

The School Counselor's Role in Addressing the Advanced Placement Equity and Excellence Gap for African-American Students

ERIC Educational Resources Information Center

Davis, Pamela; Davis, Michael P.; Mobley, Jerry A.

2014-01-01

This study describes the collaboration among a school counselor, a school counselor intern, an Advanced Placement Psychology teacher, and a counselor educator to improve African-American access to Advanced Placement (AP) coursework and increase success on the AP Psychology national examination. The team initiated a process that recruited African…

Hispanic Student Performance on Advanced Placement Exams: A Multiyear, National Investigation

ERIC Educational Resources Information Center

Jara, Teresa Dianne

2013-01-01

Purpose: The purpose of this study was to analyze the Advanced Placement exams that Hispanic students complete and to compare their overall performance with the performance of White students from 2000 to 2012. A second purpose was to determine which Advanced Placement exams were the most difficult exams for Hispanic students and which Advanced…

A Critical Investigation of Advanced Placement U.S. History Textbooks

ERIC Educational Resources Information Center

Cramer, Gregory J.

2012-01-01

This dissertation critically investigates how Advanced Placement (AP) U.S. History textbooks portray key events in Latino/a history. The investigation is made in light of claims made by the College Board, the ACLU, scholars, and federal and state governments that the Advanced Placement program is the path to educational equity for Latino/a…

The Disappearing Continent: A Critique of the Revised Advanced Placement European History Examination

ERIC Educational Resources Information Center

Randall, David

2016-01-01

This document extends the National Association of Scholars' (NAS's) critique of the College Board from Advanced Placement U.S. History (APUSH) to Advanced Placement European History (APEH). The College Board distorts APEH in the same way that it distorted the first version of APUSH. The traditional history of Europe tells how Europeans, uniquely,…

Testing FlowTracker2 Performance and Wading Rod Flow Disturbance in Laboratory Tow Tanks

NASA Astrophysics Data System (ADS)

Fan, X.; Wagenaar, D.

2016-12-01

The FlowTracker2 was released in February 2016 by SonTek (Xylem) to be a more feature-rich and technologically advanced replacement to the Original FlowTracker ADV. These instruments are Acoustic Doppler Velocimeters (ADVs) used for taking high-precision wading discharge and velocity measurements. The accuracy of the FlowTracker2 probe was tested in tow tanks at three different facilities: the USGS Hydrologic Instrumentation Facility (HIF), the Swiss Federal Institute for Metrology (METAS), and at the SonTek Research and Development facility. Multiple mounting configurations were examined, including mounting the ADV probe directly to the tow carts, and incorporating the two most-used wading rods for the FlowTracker (round and hex). Tow speeds ranged from 5cm/s to 1.5m/s, and different tow tank seeding schemes and wait times were examined. In addition, the performance of the FlowTracker2 probe in low Signal-to-Noise Ratio (SNR) environments was compared to the Original FlowTracker ADV. Results confirmed that the FlowTracker2 probe itself performed well within the 1%+0.25cm/s accuracy specification advertised. Tows using the wading rods created a reduced measured velocity by 1.3% of the expected velocity due to flow disturbance, a result similar to the Original FlowTracker ADV despite the change in the FlowTracker2 probe design. Finally, due to improvements in its electronics, the FlowTracker2's performance in low SNR tests exceeded that of the Original FlowTracker ADV, showing less standard error in these conditions compared to its predecessor.

Film Delivery Module For Fiber Placement Fabrication of Hybridized Composite Structures

NASA Technical Reports Server (NTRS)

Hulcher, Anthony Bruce; Young, Greg

2005-01-01

A new fabrication technology has been developed at the NASA Marshall Space Flight Center that will allow for the fabrication of hybridized composite structures using fiber placement processing. This technology was originally developed in response to a need to address the issue of hydrogen permeation and microcracking in cryogenic propellant tanks. Numerous thin polymeric and metallized films were investigated under low temperatures conditions for use as barrier films in a composite tank. Manufacturing studies conducted at that time did not address the processing issues related to fabrication of a hybridized tank wall. A film processing head was developed that will allow for the processing of thin polymeric and metallized films, metallic foils, and adhesives using fiber placement processing machinery. The film head is designed to enable the simultaneous processing of film materials and composite tape/tow during the composite part layup process and is also capable of processing the film during an independent operation. Several initial demonstrations were conducted to assess the performance of the film module device. Such assessments included film strip lay-up accuracy, capability to fabricate panels having internal film liners, and fabrication of laminates with embedded film layers.

Polymer infiltration studies

NASA Technical Reports Server (NTRS)

Marchello, Joseph M.

1992-01-01

Significant progress has been made during the past three months on the preparation of carbon fiber composites using advanced polymer resins. The results are set forth in recent reports and publications, and will be presented at forthcoming national and international meetings. Current and ongoing research activities reported herein include: powdered tow ribbonizing; unitape from powdered tow; customized towpreg for textiles and ATP; and textile composite research. During the period ahead research will be directed toward further development of the new powder curtain prepregging method and on ways to customize dry powder towpreg for textile and robotic applications in aircraft part fabrication. Studies of multi-tow powder prepregging and ribbon preparation will be initiated in conjunction with continued development of prepregging technology and the various aspects of composite part fabrication using customized towpreg. Also, a major effort during the coming months will be participating in the analysis of the performance of the new solution prepregger.

Preparing Students for Advanced Placement: An Evaluation of the Academic Contributions of Enrollment in Pre-AP Middle School Programs

ERIC Educational Resources Information Center

Benvenuto, Charles M.

2017-01-01

Over the past 20 years, the College Board has expanded its Advanced Placement program to consist of over 30 courses offered to millions of students throughout the United States. While more students are enrolling in AP courses, the percentage of students passing the exams has declined. With students enrolling in the Advanced Placement courses as…

Evaluation of the towplow for Caltrans operations.

DOT National Transportation Integrated Search

2015-09-30

Caltrans requested that the Advanced Highway Maintenance and Construction Technology Research Center (AHMCT) research center configure, procure, and deploy two Viking-Cives TowPlow systems and conduct an extensive evaluation to determine the most ben...

Automated Composites Processing Technology: Film Module

NASA Technical Reports Server (NTRS)

Hulcher, A. Bruce

2004-01-01

NASA's Marshall Space Flight Center (MSFC) has developed a technology that combines a film/adhesive laydown module with fiber placement technology to enable the processing of composite prepreg tow/tape and films, foils or adhesives on the same placement machine. The development of this technology grew out of NASA's need for lightweight, permeation-resistant cryogenic propellant tanks. Autoclave processing of high performance composites results in thermally-induced stresses due to differences in the coefficients of thermal expansion of the fiber and matrix resin components. These stresses, together with the reduction in temperature due to cryogen storage, tend to initiate microcracking within the composite tank wall. One way in which to mitigate this problem is to introduce a thin, crack-resistant polymer film or foil into the tank wall. Investigation into methods to automate the processing of thin film or foil materials into composites led to the development of this technology. The concept employs an automated film supply and feed module that may be designed to fit existing fiber placement machines, or may be designed as integral equipment to new machines. This patent-pending technology can be designed such that both film and foil materials may be processed simultaneously, leading to a decrease in part build cycle time. The module may be designed having a compaction device independent of the host machine, or may utilize the host machine's compactor. The film module functions are controlled by a dedicated system independent of the fiber placement machine controls. The film, foil, or adhesive is processed via pre-existing placement machine run programs, further reducing operational expense.

Tack Measurements of Prepreg Tape at Variable Temperature and Humidity

NASA Technical Reports Server (NTRS)

Wohl, Christopher; Palmieri, Frank L.; Forghani, Alireza; Hickmott, Curtis; Bedayat, Houman; Coxon, Brian; Poursartip, Anoush; Grimsley, Brian

2017-01-01

NASA’s Advanced Composites Project has established the goal of achieving a 30 percent reduction in the timeline for certification of primary composite structures for application on commercial aircraft. Prepreg tack is one of several critical parameters affecting composite manufacturing by automated fiber placement (AFP). Tack plays a central role in the prevention of wrinkles and puckers that can occur during AFP, thus knowledge of tack variation arising from a myriad of manufacturing and environmental conditions is imperative for the prediction of defects during AFP. A full design of experiments was performed to experimentally characterize tack on 0.25-inch slit-tape tow IM7/8552-1 prepreg using probe tack testing. Several process parameters (contact force, contact time, retraction speed, and probe diameter) as well as environmental parameters (temperature and humidity) were varied such that the entire parameter space could be efficiently evaluated. Mid-point experimental conditions (i.e., parameters not at either extrema) were included to enable prediction of curvature in relationships and repeat measurements were performed to characterize experimental error. Collectively, these experiments enable determination of primary dependencies as well as multi-parameter relationships. Slit-tape tow samples were mounted to the bottom plate of a rheometer parallel plate fixture using a jig to prevent modification of the active area to be interrogated with the top plate, a polished stainless steel probe, during tack testing. The probe surface was slowly brought into contact with the pre-preg surface until a pre-determined normal force was achieved (2-30 newtons). After a specified dwell time (0.02-10 seconds), during which the probe substrate interaction was maintained under displacement control, the probe was retracted from the surface (0.1-50 millimeters per second). Initial results indicated a clear dependence of tack strength on several parameters, with a particularly strong dependence on temperature and humidity. Although an increase in either of these parameters reduces tack strength, a maximum in tack was predicted to occur under conditions of low temperature and moderate humidity.

Test and analysis results for composite transport fuselage and wing structures

NASA Technical Reports Server (NTRS)

Deaton, Jerry W.; Kullerd, Susan M.; Madan, Ram C.; Chen, Victor L.

1992-01-01

Automated tow placement (ATP) and stitching of dry textile composite preforms followed by resin transfer molding (RTM) are being studied as cost effective manufacturing processes for obtaining damage tolerant fuselage and wing structures for transport aircraft. Data are presented to assess the damage tolerance of ATP and RTM fuselage elements with stitched-on stiffeners from compression tests of impacted three J-stiffened panels and from stiffener pull-off tests. Data are also presented to assess the damage tolerance of RTM wing elements which had stitched skin and stiffeners from impacted single stiffener and three blade stiffened compression tests and stiffener pull-off tests.

COURSE OUTLINE AND TEACHING GUIDE FOR ADVANCED STANDING ENGLISH II.

ERIC Educational Resources Information Center

THOMPSON, PHILLIP

THE ADVANCED STANDING PROGRAM IN ENGLISH IS DESIGNED TO PREPARE SELECTED STUDENTS FOR THE ADVANCED PLACEMENT CLASSES, WHICH ARE EQUIVALENT OF COLLEGE FRESHMAN ENGLISH, IN HIGH SCHOOL. WHILE KEEPING ADVANCED PLACEMENT NEEDS IN MIND, EMPHASIS IN CURRICULUM IS PLACED ON THE MORE IMPORTANT GOAL OF BETTER COLLEGE PREPARATION IN ENGLISH. THE ADVANCED…

Advanced Placement and International Baccalaureate: Do They Deserve Gold Star Status?

ERIC Educational Resources Information Center

Byrd, Sheila

2007-01-01

For many people committed to strong academic standards, the "advanced" high school courses offered through the College Board's Advanced Placement program and, increasingly, the Diploma Programme of the International Baccalaureate Organisation (IBO) represent the curricular gold standard for secondary education. Admissions directors and…

Where Should We Go With Advanced Placement?

NASA Astrophysics Data System (ADS)

Lichten, William

2001-04-01

This is a review of the Advanced Placement (AP)Program. In disagreement with claims of the College Board, there is firm evidence that the average test performance level has dropped. The College Board's scale and claims for AP qualification disagree seriously with college standards. A majority of tests taken do not qualify. It appears that "advanced placement" is coming closer to "placement." This paper recommends that the College Board's policy, which previously has concentrated on the numbers of participants, should include an emphasis on student performance and program quality. AP could accomplish its goal of reaching a wider range of students by changing along the lines followed in college introductory physics courses: multiple tracks.

3D forward modeling and response analysis for marine CSEMs towed by two ships

NASA Astrophysics Data System (ADS)

Zhang, Bo; Yin, Chang-Chun; Liu, Yun-He; Ren, Xiu-Yan; Qi, Yan-Fu; Cai, Jing

2018-03-01

A dual-ship-towed marine electromagnetic (EM) system is a new marine exploration technology recently being developed in China. Compared with traditional marine EM systems, the new system tows the transmitters and receivers using two ships, rendering it unnecessary to position EM receivers at the seafloor in advance. This makes the system more flexible, allowing for different configurations (e.g., in-line, broadside, and azimuthal and concentric scanning) that can produce more detailed underwater structural information. We develop a three-dimensional goal-oriented adaptive forward modeling method for the new marine EM system and analyze the responses for four survey configurations. Oceanbottom topography has a strong effect on the marine EM responses; thus, we develop a forward modeling algorithm based on the finite-element method and unstructured grids. To satisfy the requirements for modeling the moving transmitters of a dual-ship-towed EM system, we use a single mesh for each of the transmitter locations. This mitigates the mesh complexity by refining the grids near the transmitters and minimizes the computational cost. To generate a rational mesh while maintaining the accuracy for single transmitter, we develop a goal-oriented adaptive method with separate mesh refinements for areas around the transmitting source and those far away. To test the modeling algorithm and accuracy, we compare the EM responses calculated by the proposed algorithm and semi-analytical results and from published sources. Furthermore, by analyzing the EM responses for four survey configurations, we are confirm that compared with traditional marine EM systems with only in-line array, a dual-ship-towed marine system can collect more data.

High Altitude Towed Glider

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.

1996-01-01

The concept of using an unmanned towed glider for high altitude scientific research had been previously proposed. This paper examines the feasibility of this concept by determining what impact the various characteristics of the tow line, glider and tow aircraft have on tow line drag. A description of the analysis and computer code used to generate the results is given. The parameters examined were glider altitude, tow aircraft glider separation distance, velocity, tow line drag coefficient and tow line material properties. The results from the analysis show that the tow line drag increases significantly with tow aircraft/glider separation. The drag increased from 940 N (211 lb) with a tow aircraft/glider separation of 3 km to 11,970 N (2691 lb) with a tow aircraft/glider separation of 10 km. The results also show that by varying some of the initial assumptions significant reductions in tow line drag and weight can be obtained. The variables which had the greatest effect on reducing the tow line drag were the decrease in tow aircraft/glider separation distance, the increase in tow line strength and the decrease in glider Mach number.

BIBLIOGRAPHIC GUIDE FOR ADVANCED PLACEMENT, CHEMISTRY.

ERIC Educational Resources Information Center

WILLIAMS, HARRY; KING, CLYDE

REFERENCES AND AUDIOVISUAL MATERIALS ARE LISTED IN THIS GUIDE FOR SECONDARY SCHOOL ADVANCED PLACEMENT CHEMISTRY TEACHERS AND LIBRARIANS. BOOKS, PERIODICALS, WALL CHARTS, FILMS, AND FILMSTRIPS ARE INCLUDED. CITATIONS ARE COMPLETE AND INCLUDE INFORMATION PERTINENT TO THE ACQUISITION OF THE MATERIALS. (AG)

A Salute to Advanced Placement Art

ERIC Educational Resources Information Center

Nelson, Kathryn McDonald

1978-01-01

Ten years have passed since the original proposal was written to establish Advanced Placement Studio Art and History of Art as one of the 13 College Board AP disciplines. This review includes examples of AP high school students' work. (Author/LBH)

Reaching the Next Stephen Hawking: Five Ways to Help Students with Disabilities in Advanced Placement Science Classes

ERIC Educational Resources Information Center

Howard, Lori A.; Potts, Elizabeth A.; Linz, Ed

2013-01-01

As the federal government encourages all students to attempt advanced math and science courses, more students with disabilities are enrolling in Advanced Placement (AP) science classes. AP science teachers can better serve these students by understanding the various types of disabilities (whether physical, learning, emotional, or behavioral),…

Process for preparing composite articles from composite fiber blends

NASA Technical Reports Server (NTRS)

McMahon, Paul E. (Inventor); Chung, Tai-Shung (Inventor); Ying, Lincoln (Inventor)

1989-01-01

A composite article is prepared by forming a continuous tow of continuous carbon fibers, forming a continuous tow of thermoplastic polymer fibers, uniformly and continuously spreading the thermoplastic polymer fibers to a selected width, uniformly and continuously spreading the carbon fiber tow to a width that is essentially the same as the selected width for the thermoplastic polymer fiber tow, intermixing the tows intimately, uniformly and continuously, in a relatively tension-free state, continuously withdrawing the intermixed tow and applying the tow to a mold and heating the tow.

The Effect of Enrollment in Middle School Challenge Courses on Advanced Placement Exams in Social Studies and Science

ERIC Educational Resources Information Center

Glaude-Bolte, Katherine

2010-01-01

Educators seek to guide students through appropriate programs and courses that prepare them for future success, in more advanced coursework and in other challenges of life. Some middle schools offer Challenge, or honors, courses for students who have demonstrated high ability. High schools often offer Advanced Placement (AP) courses, which are…

Impact of Advanced Grade 8 U.S. History on Participation and Performance in Advanced Placement Social Studies Courses in Grade 9

ERIC Educational Resources Information Center

Maina, Nyambura Susan

2015-01-01

At the request of the Office of Curriculum and Instructional Programs, the Office of Shared Accountability examined the impact of offering Advanced Grade 8 U.S. History on enrollment and performance in Advanced Placement (AP) social studies courses in Grade 9. The study compared Grade 9 enrollment and performance in AP U.S. History or AP U.S.…

Modern Agriculture in Advanced Placement Human Geography.

ERIC Educational Resources Information Center

Lanegran, David A.

2000-01-01

Discusses the four sections of the Advanced Placement (AP) human geography course focusing on agriculture: (1) development and diffusion of agriculture; (2) major agricultural production regions; (3) rural land use and change; and (4) impacts of modern agricultural change. Includes references and a resource list. (CMK)

Teaching Melodic Dictation in Advanced Placement Music Theory

ERIC Educational Resources Information Center

Paney, Andrew S.; Buonviri, Nathan O.

2014-01-01

In this study approaches to teaching melodic dictation skills used by Advanced Placement (AP) Music Theory teachers were examined. Twelve high school teachers from four states were interviewed. Four themes emerged from the interview transcripts: cognitive frameworks, processing strategies, rhythm, and course design. Participants generally…

Continuous, linearly intermixed fiber tows and composite molded article thereform

NASA Technical Reports Server (NTRS)

McMahon, Paul E. (Inventor); Chung, Tai-Shung (Inventor); Ying, Lincoln (Inventor)

2000-01-01

The instant invention involves a process used in preparing fibrous tows which may be formed into polymeric plastic composites. The process involves the steps of (a) forming a carbon fiber tow; (b) forming a thermoplastic polymeric fiber tow; (c) intermixing the two tows; and (d) withdrawing the intermixed tow for further use.

Clinical evaluation of radiotherapy for advanced esophageal cancer after metallic stent placement

PubMed Central

Yu, You-Tao; Yang, Guang; Liu, Yan; Shen, Bao-Zhong

2004-01-01

AIM: To evaluate the therapeutic effect of radiotherapy for esophageal cancer after expandable metallic stent placement. METHODS: Ten cases of advanced esophageal cancer were evaluated, 7 having complete obstruction and 3 with digestive-respiratory fistula. Ten nitinol stents were placed at the site of stenosis. Patients were treated with a total dose of 1200 cGy divided into 3 fractions of 400 cGy 4-7 d after stents placement. RESULTS: All the 10 stents were placed successfully at one time. After radiotherapy for advanced esophageal cancer, the survival period of the cases ranged from 14 to 22 mo, with a mean survival of 17 mo. No re-stenosis occurred among all the 10 cases. CONCLUSION: Stent placement combined with radiotherapy for esophageal cancer is helpful to prolong patients’ survival and reduce occurrence of re-stenosis. PMID:15237455

Process for preparing tows from composite fiber blends

NASA Technical Reports Server (NTRS)

McMahon, Paul (Inventor); Chung, Tai-Shung (Inventor); Ying, Lincoln (Inventor)

1989-01-01

A continuous, substantially uniform tow useful in forming composite molded articles is prepared by forming a continuous tow of continuous carbon fibers, forming a continuous tow of thermoplastic polymer fibers to a selected width, uniformly and continuously spreading the carbon fiber two to a width that is essentially the same as the selected width for the thermoplastic polymer fiber tow, intermixing the tows intimately, uniformly and continuously, in a relatively tension-free state, and continuosuly withdrawing the intermixed tow.

Composite Structures and Materials Research at NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Starnes, James H., Jr.; Dexter, H. Benson; Johnston, Norman J.; Ambur, Damodar R.; Cano, roberto J.

2003-01-01

A summary of recent composite structures and materials research at NASA Langley Research Center is presented. Fabrication research to develop low-cost automated robotic fabrication procedures for thermosetting and thermoplastic composite materials, and low-cost liquid molding processes for preformed textile materials is described. Robotic fabrication procedures discussed include ply-by-ply, cure-on-the-fly heated placement head and out-of-autoclave electron-beam cure methods for tow and tape thermosetting and thermoplastic materials. Liquid molding fabrication processes described include Resin Film Infusion (RFI), Resin Transfer Molding (RTM) and Vacuum-Assisted Resin Transfer Molding (VARTM). Results for a full-scale composite wing box are summarized to identify the performance of materials and structures fabricated with these low-cost fabrication methods.

Composite Structures and Materials Research at NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Starnes, James H., Jr.; Dexter, H. Benson; Johnston, Norman J.; Ambur, Damodar R.; Cano, Roberto J.

2001-01-01

A summary of recent composite structures and materials research at NASA Langley Research Center is presented. Fabrication research to develop low-cost automated robotic fabrication procedures for thermosetting and thermoplastic composite materials, and low-cost liquid molding processes for preformed textile materials is described. Robotic fabrication procedures discussed include ply-by-ply, cure-on-the-fly heated placement head and out-of-autoclave electron-beam cure methods for tow and tape thermosetting and thermoplastic materials. Liquid molding fabrication processes described include Resin Film Infusion (RFI) Resin Transfer Molding (RTM) and Vacuum-Assisted Resin Transfer Molding (VARTM). Results for a full-scale composite wing box are summarized to identify the performance of materials and structures fabricated with these low-cost fabrication methods.

Advanced Placement Economics. Macroeconomics: Student Activities.

ERIC Educational Resources Information Center

Morton, John S.

This book is designed to help advanced placement students better understand macroeconomic concepts through various activities. The book contains 6 units with 64 activities, sample multiple-choice questions, sample short essay questions, and sample long essay questions. The units are entitled: (1) "Basic Economic Concepts"; (2) "Measuring Economic…

BIBLIOGRAPHIC GUIDE FOR ADVANCED PLACEMENT, LATIN.

ERIC Educational Resources Information Center

BARRON, ROBERT; ROSELLE, LEONE

LITERARY AND CRITICAL WORKS, REFERENCE BOOKS, PERIODICALS, RECORDS, FILMS, AND FILMSTRIPS DEALING WITH ROMAN LITERATURE, HISTORY, CIVILIZATION, MYTHOLOGY, AND LANGUAGE ARE INCLUDED IN THIS BIBLIOGRAPHY OF RECOMMENDED READING IN ENGLISH FOR ADVANCED PLACEMENT PROGRAMS IN LATIN. THE LIST IS DIVIDED INTO TWO $500 GROUPS, SO THAT FOR CONVENIENCE IN…

Aspiration, Performance, Reward: The Advanced Placement Program at 40.

ERIC Educational Resources Information Center

Rothschild, Eric

1995-01-01

The history of the College Entrance Examination Board's Advanced Placement Program is chronicled from its conception in 1951 through early developmental stages and 40 years of implementation. Issues discussed include test development, funding, administration at the institutional level, expansion of curriculum areas and testing options, teacher…

What Do You Mean You Don't Do Advanced Placement?: Confessions of an Educational Heretic.

ERIC Educational Resources Information Center

Briley, Ron

2000-01-01

Explains why Advanced Placement courses are not offered at Sandia Preparatory School, a college preparatory school located in Albuquerque, New Mexico. Focuses on the school mission, overall philosophy, and how this relates to the history classroom in particular. (CMK)

Engaging High School Students in Advanced Math and Science Courses for Success in College: Is Advanced Placement the Answer?

ERIC Educational Resources Information Center

Kelley-Kemple, Thomas; Proger, Amy; Roderick, Melissa

2011-01-01

The current study provides an in-depth look at Advanced Placement (AP) math and science course-taking in one school district, the Chicago Public Schools (CPS). Using quasi-experimental methods, this study examines the college outcomes of students who take AP math and science courses. Specifically, this study asks whether students who take AP math…

Investigation of the Forces Acting on Gliders in Automobile-pulley-winch and Airplane Towed Flight

NASA Technical Reports Server (NTRS)

Klemperer, W B

1942-01-01

The magnitude, the direction, and the fluctuation of towing forces exerted upon gliders by towing them aloft behind an automobile, by means of a winch, and by airplane were measured under a variety of conditions covering a range from gentle to severe types of operation. For these tests the towing forces did not exceed 92 percent of the gross weight of the glider. The results indicate that in pulley and winch towing the towing forces are of about the same magnitude as in automobile towing. Speed increases in the accelerated phases of the towing jerks encountered in airplane towing can readily become critical as speeds in excess of placard speeds can be attained. Passage through the slipstream of the towing airplane can be equivalent to a severe gust that, at high speed, may impose high wing loads and require large control moments.

Fiber coating method

DOEpatents

Corman, Gregory Scot

2003-04-15

A coating is applied to reinforcing fibers arranged into a tow by coaxially aligning the tow with an adjacent separation layer and winding or wrapping the tow and separation layer onto a support structure in an interleaved manner so that the separation layer separates a wrap of the tow from an adjacent wrap of the tow. A coating can then be uniformly applied to the reinforcing fibers without defects caused by fiber tow to fiber tow contact. The separation layer can be a carbon fiber veil.

Advanced Placement Economics Improves Both Merit and Equity

ERIC Educational Resources Information Center

Meek, Sally; Morton, John

2009-01-01

In 1989, microeconomics and macroeconomics examinations debuted on the Advanced Placement (AP) scene. At that time, many professors of economics were skeptical that college freshmen had the skills and maturity to understand the concepts in principles of economics courses. They thought teaching these concepts to high school students was even more…

Democracy in America: Starting at the Source.

ERIC Educational Resources Information Center

Serow, Ann G.

1986-01-01

This article notes that the May 1987 release of the College Board's advanced placement exam in American government gives high school social studies departments good reason to reassess and improve their advanced placement programs. It shows how Alexis de Toqueville's classic 1935 work, "Democracy in America," may be used as a central…

Cities and Urban Land Use in Advanced Placement Human Geography.

ERIC Educational Resources Information Center

Ford, Larry R.

2000-01-01

Discusses the cities and urban land use section of the Advanced Placement (AP) human geography course, focusing on the: (1) definitions of urbanism; (2) origin and evolution of cities; (3) functional character of contemporary cities; (4) built environment and social space; and (5) responses to urban growth. (CMK)

75 FR 75666 - Advanced Placement (AP) Test Fee Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-06

... DEPARTMENT OF EDUCATION [CFDA No. 84.330B] Advanced Placement (AP) Test Fee Program AGENCY: Office... AP Test Fee fiscal year (FY) 2011 competition. SUMMARY: On September 1, 2010, we published in the Federal Register (75 FR 53681) a notice inviting applications for the AP Test Fee FY 2011 competition...

The Advanced Placement Arms Race and the Reproduction of Educational Inequality

ERIC Educational Resources Information Center

Klugman, Joshua

2013-01-01

Background: Access to Advanced Placement (AP) courses is stratified by class and race. Researchers have identified how schools serving disadvantaged students suffer from various kinds of resource deprivations, concluding that interventions are needed to equalize access to AP courses. On the other hand, the theory of Effectively Maintained…

In the Classroom: "If You Build It, They Will Come."

ERIC Educational Resources Information Center

Hargrove, Kathy

2003-01-01

This article discusses the experiences gifted secondary students have had with pre-Advanced Placement, Advanced Placement, and International Baccalaureate programs. Key traits essential for teachers of the gifted are identified: a high degree of intelligence; extensive knowledge of the subject matter; emotional maturity; and a strong self-concept.…

Advanced Placement Economics. Teacher Resource Manual.

ERIC Educational Resources Information Center

Morton, John S.

This book, in conjunction with the student activities books for macroeconomics and microeconomics, is designed for teaching the Advanced Placement Economics course. The book contains five units for the microeconomic portion and six units for the macroeconomic portion of the text. Along with the many activities are sample multiple-choice questions,…

Melodic Dictation Instruction: A Survey of Advanced Placement Music Theory Teachers

ERIC Educational Resources Information Center

Buonviri, Nathan O.; Paney, Andrew S.

2015-01-01

Based on relevant literature and recent qualitative findings, the purpose of this survey research was to identify pedagogical approaches to melodic dictation employed by Advanced Placement (AP) Music Theory teachers across the United States. The researcher-designed survey questions focused on pitch and rhythm skills, instructional resources,…

Advanced Placement Mathematics Calculus, Grade 12 Curriculum Guide.

ERIC Educational Resources Information Center

Scharf, John; And Others

This document is a guide to the advanced placement program in calculus for grade 12 in the city schools in Warren, Ohio. The program covers analytic geometry, differential and integral calculus of algebraic functions, elementary transcendental functions, and applications of differentiation and integration. The philosophy and aims of the program…

The Effects of Advanced Placement and International Baccalaureate Programs on Student Achievement

ERIC Educational Resources Information Center

Luo, Samia Merza

2013-01-01

This study compared student academic achievement in two college readiness programs, Advanced Placement (AP) and International Baccalaureate (IB) and attempted to determine how well program participation predict student performance compared to variables such as SES, parent education level, GPA, gender, and SAT II scores. Finally, the research…

ISAAC Advanced Composites Research Testbed

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey; Stewart, Brian K.; Martin, Robert A.

2014-01-01

The NASA Langley Research Center is acquiring a state-of-art composites fabrication capability to support the Center's advanced research and technology mission. The system introduced in this paper is named ISAAC (Integrated Structural Assembly of Advanced Composites). The initial operational capability of ISAAC is automated fiber placement, built around a commercial system from Electroimpact, Inc. that consists of a multi-degree of freedom robot platform, a tool changer mechanism, and a purpose-built fiber placement end effector. Examples are presented of the advanced materials, structures, structural concepts, fabrication processes and technology development that may be enabled using the ISAAC system. The fiber placement end effector may be used directly or with appropriate modifications for these studies, or other end effectors with different capabilities may either be bought or developed with NASA's partners in industry and academia.

Advances in circular stapling technique for gastric bypass: transoral placement of the anvil.

PubMed

Nguyen, Ninh T; Hinojosa, Marcelo W; Smith, Brian R; Reavis, Kevin M; Wilson, Samuel E

2008-05-01

In Roux-en-Y gastric bypass, construction of the gastrojejunostomy is commonly performed using a circular stapler. The initial description for placement of the anvil was via the transoral approach. Although the concept was ingenious, technical difficulty was encountered during passage resulting in complications such as hypopharyngeal perforation and esophageal mucosal injury. As a result, most surgeons subsequently changed their route of anvil placement to the transabdominal approach. Advances in stapler technology now allow the head of the anvil to be pre-tilted, permitting transoral introduction with greater ease and safety. This paper describes this improved method for transoral placement of the anvil during laparoscopic gastric bypass and reoperative bariatric surgery.

A Quantitative Comparative Study of Blended and Traditional Models in the Secondary Advanced Placement Statistics Classroom

ERIC Educational Resources Information Center

Owens, Susan T.

2017-01-01

Technology is becoming an integral tool in the classroom and can make a positive impact on how the students learn. This quantitative comparative research study examined gender-based differences among secondary Advanced Placement (AP) Statistic students comparing Educational Testing Service (ETS) College Board AP Statistic examination scores…

Photoelectron Spectroscopy in Advanced Placement Chemistry

ERIC Educational Resources Information Center

Benigna, James

2014-01-01

Photoelectron spectroscopy (PES) is a new addition to the Advanced Placement (AP) Chemistry curriculum. This article explains the rationale for its inclusion, an overview of how the PES instrument records data, how the data can be analyzed, and how to include PES data in the course. Sample assessment items and analysis are included, as well as…

Advanced Placement and International Baccalaureate Programs: A "Fit" for Gifted Learners?

ERIC Educational Resources Information Center

Hertberg-Davis, Holly; Callahan, Carolyn M.; Kyburg, Robin M.

2006-01-01

Although limited research exists on the appropriateness of Advanced Placement (AP) and International Baccalaureate (IB) Programs for gifted secondary learners, these courses serve as the primary methods of meeting the needs of gifted students in most high schools. This qualitative study employed a grounded theory approach to investigate how…

Perspectives of Advanced Placement U.S. History Teachers in Title I Schools

ERIC Educational Resources Information Center

Rowland, Mark Lance

2017-01-01

The College Board's Advanced Placement (AP) Program continues to expand annually with increased numbers of high school students nationwide enrolling in AP courses and taking end-of-course AP exams, in hopes of earning college credit and strengthening high school transcripts. As the College Board promotes increased minority student participation…

Advanced Placement U.S. History and the Application of Social Justice

ERIC Educational Resources Information Center

Curry, Katherine A.; Sabina, Lou L.; Loffi, Jon

2016-01-01

Recent changes to Advanced Placement U.S. History have sparked a national debate concerning goals and purposes of college level history courses. Critics suggest that the revisions result in a national curriculum that promotes a revisionist history perspective. Defenders claim that revisions are an important step in preparing students for 21st…

Advanced Placement Course Enrollment and School-Level Characteristics

ERIC Educational Resources Information Center

Barnard-Brak, Lucy; McGaha-Garnett, Valerie; Burley, Hansel

2011-01-01

The current study examined access to Advanced Placement (AP) courses as a function of these school characteristics (e.g., percentage of ethnic minority and lower socioeconomic status) and then examined AP course enrollment as a function of both access to AP courses and these school characteristics. Using structural equation modeling techniques,…

SREB States Maintain Lead in Advanced Placement and International Baccalaureate Programs

ERIC Educational Resources Information Center

Collins, Crystal

2009-01-01

The Southern Regional Education Board (SREB) states lead the nation in student participation in Advanced Placement (AP) and International Baccalaureate (IB) programs. The region also continued to match the nation in the success rates of high school students on AP exams in 2008. SREB's "Challenge to Lead" Goals for Education recognize the…

Advanced Placement and Rural Schools: Access, Success, and Exploring Alternatives

ERIC Educational Resources Information Center

Gagnon, Douglas J.; Mattingly, Marybeth J.

2016-01-01

Completing Advanced Placement (AP) coursework is an important part of the selective college admissions process, and access to AP coursework can be viewed as a measure of equal opportunity. Relatively little research has fully examined how access to AP coursework is mediated by school characteristics. Rural schools are at a particular disadvantage…

77 FR 24480 - Application for New Awards; Advanced Placement (AP) Test Fee Program-Reopening the AP Test Fee...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-24

... DEPARTMENT OF EDUCATION Application for New Awards; Advanced Placement (AP) Test Fee Program--Reopening the AP Test Fee Fiscal Year 2012 Competition AGENCY: Office of Elementary and Secondary Education (OESE), Department of Education. ACTION: Notice reopening the AP Test Fee fiscal year 2012 competition...

Surviving a Midlife Crisis: Advanced Placement Turns Fifty

ERIC Educational Resources Information Center

Mollison, Andrew

2006-01-01

In 1956, 1,220 college-bound juniors and seniors in 104 American high schools took the first Advanced Placement (AP) exams conducted by the Educational Testing Service for the College Board. The AP program was unabashedly elitist and designed to fortify the education of the nation's future leaders in anticipation of Cold War national security…

A TENTATIVE GUIDE, DIFFERENTIAL AND INTEGRAL CALCULUS.

ERIC Educational Resources Information Center

BRANT, VINCENT; GERARDI, WILLIAM

THE COURSE IS INTENDED TO GO BEYOND THE REQUIREMENTS OF THE ADVANCED PLACEMENT PROGRAM IN MATHEMATICS AS DESIGNED BY THE COLLEGE ENTRANCE EXAMINATION BOARD. THE ADVANCED PLACEMENT PROGRAM CONSISTS OF A 1-YEAR COURSE COMBINING ANALYTIC GEOMETRY AND CALCULUS. PRESUPPOSED HERE ARE--A SEMESTER COURSE IN ANALYTIC GEOMETRY AND A THOROUGH KNOWLEDGE OF…

Preparing Students for Advanced Placement Spanish Literature: Content Sequencing of the Reading Skill.

ERIC Educational Resources Information Center

Stein, Roger D.

1985-01-01

Describes a reading-skill-building curriculum that prepares students to handle the reading in the Advanced Placement Spanish Literature course, a course that treats the works of Borges, Garcia Lorca, Matute, Neruda, and Unamuno. Suggests techniques and texts that aid in the teaching of these skills. (SED)

Examining the Impact of State Level Merit-Aid Policies on Advanced Placement Participation

ERIC Educational Resources Information Center

Kramer, Dennis A., II

2016-01-01

This study examines the impact of merit-aid programs on secondary course taking patterns. Specifically, this study uses difference-in-differences to analyze state-level Advanced Placement (AP) participation and examination data pre and post merit-aid adoption. Results indicate increases in AP participation and number of total examinations after…

Raising Rigor, Getting Results: Lessons Learned from AP Expansion

ERIC Educational Resources Information Center

Wakelyn, David

2009-01-01

Advanced Placement (AP), which enables high school students to take introductory college-level courses, is the nation's oldest example of a rigorous, common curriculum. Students who score well on AP exams are more likely to persist in college and earn a degree. The Advanced Placement Expansion project of the National Governors Association Center…

Science and Mathematics Advanced Placement Exams: Growth and Achievement over Time

ERIC Educational Resources Information Center

Judson, Eugene

2017-01-01

Rapid growth of Advanced Placement (AP) exams in the last 2 decades has been paralleled by national enthusiasm to promote availability and rigor of science, technology, engineering, and mathematics (STEM). Trends were examined in STEM AP to evaluate and compare growth and achievement. Analysis included individual STEM subjects and disaggregation…

Barriers to Advanced Placement for Latino Students at the High-School Level

ERIC Educational Resources Information Center

Walker, Susan A.; Pearsall, Laura D.

2012-01-01

In order to gain a better understanding about Latino student underrepresentation in advanced placement (AP) coursework, this investigation explored the factors that inhibit and/or encourage Latino student enrollment in AP coursework at one suburban public high school in the Western United States. Latino high-school students and their parents…

The Experiences of Advanced Placement and International Baccalaureate Diploma Program Participants: A Systematic Review of Qualitative Research

ERIC Educational Resources Information Center

Park, Kelly; Caine, Vera; Wimmer, Randolph

2014-01-01

Enriched high school curricula like the Advanced Placement and International Baccalaureate Diploma programs are endorsed as "pathway programs" for postsecondary-bound students. Program participation is perceived to have benefits that appeal to a broad stakeholder group of universities, administrators, teachers, students, and parents. In…

75 FR 53681 - Office of Elementary and Secondary Education Overview Information; Advanced Placement (AP) Test...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-01

... DEPARTMENT OF EDUCATION Office of Elementary and Secondary Education Overview Information; Advanced Placement (AP) Test Fee Program; Notice Inviting Applications for New Awards for Fiscal Year (FY) 2011 Catalog of Federal Domestic Assistance (CFDA) Number: 84.330B. Dates: Applications Available: September 1, 2010. Deadline for Transmittal of...

Conceptualizing a Framework for Advanced Placement Statistics Teaching Knowledge

ERIC Educational Resources Information Center

Haines, Brenna

2015-01-01

The purpose of this article is to sketch a conceptualization of a framework for Advanced Placement (AP) Statistics Teaching Knowledge. Recent research continues to problematize the lack of knowledge and preparation among secondary level statistics teachers. The College Board's AP Statistics course continues to grow and gain popularity, but is a…

Hepatocellular Carcinoma Complicated by Gastroduodenal Obstruction: Palliative Treatment with Metallic Stent Placement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ye Jin; Kim, Jin Hyoung, E-mail: m1fenew@daum.net; Song, Ho-Young

Purpose: To evaluate the clinical effectiveness of self-expandable metallic stents in seven patients with malignant gastroduodenal obstruction caused by inoperable hepatocellular carcinoma (HCC). Methods: Seven patients with gastroduodenal obstruction caused by advanced HCC underwent metallic stent placement from 2003 to 2010. These patients had total dysphagia (n = 5) or were able to eat only liquids (n = 2) before stent placement. Patients had Eastern Cooperative Oncology Group performance scores of 2 or 3, and Child-Pugh classification B or C. Results: Stent placement was technically successful in all seven patients (100%) and clinically successful in six (86%). Five patients couldmore » eat a soft diet, and one patient tolerated regular diet after stent placement. Stent-related obstructive jaundice occurred in one patient. One patient had hematemesis 11 days after stent placement. Overall mean survival was 51 days (range, 10-119 days). Stent patency was preserved in six patients with clinical success until death. Conclusion: Placement of a covered self-expandable metallic stent may offer good palliation in patients with gastroduodenal obstruction due to advanced HCC.« less

"Advanced Classes? They're Only for White Kids": How One Kansas School Is Changing the Face of Honors and Advanced Placement Courses

ERIC Educational Resources Information Center

Kerr, Roberta

2014-01-01

The purpose of this study was to obtain an accurate picture of minority student enrollment in honors and advanced placement (AP) classes at Wichita (Kansas) High School East and to develop a plan of action to close the achievement gap between White and non-White students. Prior to this study there was no clear, concise data to move this discussion…

Thermomechanical Characterization of SiC Fiber Tows and Implications for CMC

NASA Technical Reports Server (NTRS)

Yun, H. M.; DiCarlo, J. A.

1999-01-01

In order to better understand SiC fiber behavior within CMC microstructures, mechanical tests were performed on multifilament tows consisting of different types of as produced and pretreated fibers. Tensile strengths of tows and single fibers were measured at room temperature for nonstoichiometric Hi-Nicalon and ZMI fibers and for stoichiometric Hi-Nicalon-S, Tyranno SA. and Sylramic fibers. Based on simple bundle theory, measured strengths for as-produced and sized tows were in general agreement with the single fiber results. However, after sizing removal under inert conditions, tow strengths for the coarser grained stoichiometric fibers were typically lower than those predicted from individual fiber data. This effect is attributed to enhanced fiber-fiber mechanical interaction caused by sizing removal from the rough surfaces of these fibers. In support of this, tow strengths remained high for those fiber types with fine grains or excess surface carbon; and, when re-coated with a BN interphase coating, tow strengths for the coarser grained fibers returned to their as-produced values. When the tows were pretreated in air at intermediate temperatures, tow strengths decreased in a manner that could be correlated with the oxidation characteristics of each fiber type as measured by thermogravimetric analysis. The creep and rupture properties of Hi-Nicalon and Sylramic tows were also measured in air and argon from 1200 to 1400 C. Although displaying transient and environmental effects similar to single fibers, the tows crept faster at short times and slower at long times. This resulted in the tow rupture strengths at long time being much greater than the rupture strengths of single fibers. The CMC implications of the tow results are discussed, as well as the benefits and limitations of tow testing.

Variable Length Inflatable Ramp Launch and Recovery System

DTIC Science & Technology

2016-09-22

deployment and when not in use, for retraction . [0017] The positioning cart is the primary interface with the tow body by hosting a capture and swing...the air beams 20. The tow cable winch 14 also extends the tow cable 15 into the water to tow a tow body 100 during deployment and retraction during...for deployment and retract back into the ABDF when not in use. The positioning cart 24 is the primary interface with the tow body by hosting the

M2-F1 in flight over lakebed on tow line

NASA Image and Video Library

1963-08-16

After initial ground-tow flights of the M2-F1 using the Pontiac as a tow vehicle, the way was clear to make air tows behind a C-47. The first air tow took place on 16 August 1963. Pilot Milt Thompson found that the M2-F1 flew well, with good control. This first flight lasted less than two minutes from tow-line release to touchdown. The descent rate was 4,000 feet per minute.

Expanding the Scope of Advanced Placement Classes

ERIC Educational Resources Information Center

Lim, Victoria

2008-01-01

Dr. Paul Dosal of the University of South Florida is not impressed with the way most high school students learn about Latin American history. Dosal believes an advanced placement course in the subject will change that. He's the executive director of ENLACE Florida, a statewide network funded by the W.K. Kellogg Foundation, designed to increase the…

Ethnic and Gender Differences in Advanced Placement Exam Performance: A Multiyear National Analysis

ERIC Educational Resources Information Center

Holmes, Maria Alexander

2013-01-01

Purpose: The purpose of this study was to analyze ethnic and gender differences in Advanced Placement (AP) exam performance of U.S. high school students. Specifically, the extent to which differences exist in overall AP exam performance scores within and between four ethnic groups (i.e., Asian, Black, Hispanic, and White) was investigated. Within…

Teacher Scaffolding of Academic Language in an Advanced Placement U.S. History Class

ERIC Educational Resources Information Center

Gritter, Kristine; Beers, Scott; Knaus, Robert W.

2013-01-01

This article examines teacher scaffolding of academic language in an Advanced Placement United States History (APUSH) course throughout a school year for one student who received a perfect score on the end of year APUSH exam. Data includes four months of observation of teacher instructional strategies to scaffold student writing and vignettes of…

The Advanced Placement English Program in Salt Lake and Granite School Districts.

ERIC Educational Resources Information Center

Stratopoulos, Irene Chachas

The main purposes in examining and evaluating the Advanced Placement English Program in Salt Lake and Granite School Districts were to identify the essential curriculum features of the program, to make suggestions for curriculum improvement, and to determine whether or not the quality of the AP English Program surpassed that of the conventional…

Experiences of High-Achieving High School Students Who Have Taken Multiple Concurrent Advanced Placement Courses

ERIC Educational Resources Information Center

Milburn, Kristine M.

2011-01-01

Problem: An increasing number of high-achieving American high school students are enrolling in multiple Advanced Placement (AP) courses. As a result, high schools face a growing need to understand the impact of taking multiple AP courses concurrently on the social-emotional lives of high-achieving students. Procedures: This phenomenological…

The Impact of Advanced Placement Courses on High School Students Taking the Scholastic Aptitude Test.

ERIC Educational Resources Information Center

Thomas, L. M.; Thomas, Suzanne G.

This obtrusive post-hoc quasi-experimental study investigated Scholastic Assessment Test (SAT) scores of 111 high school students in grades 10 through 12. Fifty-three students were enrolled in at least one Advanced Placement (AP) course at the time of the study. General factorial analysis of variance (ANOVA) tested for significant differences…

Is Increased Access Enough? Advanced Placement Courses, Quality, and Success in Low-Income Urban Schools

ERIC Educational Resources Information Center

Hallett, Ronald E.; Venegas, Kristan M.

2011-01-01

This article combines descriptive statistics and interviews with college-bound high school students to explore the connection between increased access and academic quality of Advanced Placement (AP) courses in low-income urban high schools. Results suggest that although moderately more opportunities to take AP courses exist than in previous years,…

A Case Study on Teaching the Topic "Experimental Unit" and How It Is Presented in Advanced Placement Statistics Textbooks

ERIC Educational Resources Information Center

Perrett, Jamis J.

2012-01-01

This article demonstrates how textbooks differ in their description of the term "experimental unit". Advanced Placement Statistics teachers and students are often limited in their statistical knowledge by the information presented in their classroom textbook. Definitions and descriptions differ among textbooks as well as among different…

The Hawaii Teleschool: An Evaluation of Distance Learning for Advanced Placement Calculus Instruction in "Paradise."

ERIC Educational Resources Information Center

Barker, Bruce O.; Bannon, James

This paper describes the Hawaii Interactive Television System (HITS) program and provides an evaluation of the first year of broadcasts for the advanced placement (AP) calculus course. HITS allows two-way video-audio interaction among origination sites, but the configuration used by the Department of Education for its Teleschool program is the…

Amityville Memorial High School History Journal Advance Placement History.

ERIC Educational Resources Information Center

Howlett, Charles F., Ed.

The history of Amityville, New York, compiled by 11th and 12th grade advance placement history students, is presented in journal form. Six papers focus on: (1) South Oaks: The Long Island Home; (2) A History of Bethel African Methodist Episcopal Church, Amityville; (3) Amityville: A Vacationland; (4) Amityville School System from 1904 to Present;…

Coping, Stress, and Job Satisfaction as Predictors of Advanced Placement Statistics Teachers' Intention to Leave the Field

ERIC Educational Resources Information Center

McCarthy, Christopher J.; Lambert, Richard G.; Crowe, Elizabeth W.; McCarthy, Colleen J.

2010-01-01

This study examined the relationship of teachers' perceptions of coping resources and demands to job satisfaction factors. Participants were 158 Advanced Placement Statistics high school teachers who completed measures of personal resources for stress prevention, classroom demands and resources, job satisfaction, and intention to leave the field…

Advanced Placement English in a Solipsistic Era: How Structuralism Can Renew Meaning

ERIC Educational Resources Information Center

Rauh, John

2014-01-01

Advanced Placement (AP) courses within secondary English education can fail to meet the needs of gifted students in the postmodern era. Because AP courses often are standardized, despite the College Board's efforts to allow freedom in course design, gifted students, as especially attuned to discrepancies between practice and theory, are being…

AP: A Critical Examination of the Advanced Placement Program

ERIC Educational Resources Information Center

Sadler, Philip M., Ed.; Sonnert, Gerhard, Ed.; Tai, Robert H., Ed.; Klopfenstein, Kristin, Ed.

2010-01-01

With an annual yearly growth rate of 9.3 percent over the last two decades, Advanced Placement courses have become a juggernaut in American high school education. AP courses are routinely perceived as an indicator of educational rigor, and many schools push to enroll low-income or minority students in these courses in the hope of preparing them…

Advanced Placement (AP) Social Studies Teachers' Use of Academic Course Blogs as a Supplemental Resource for Student Learning

ERIC Educational Resources Information Center

Alper, Seth M.

2013-01-01

This mixed-methods study investigated the relationship between Advanced Placement (AP) social studies teachers' utilization of academic course blogs and student achievement. Simultaneously, the study examined the participating teachers' perceptions on the use of course blogs and other social media as supplemental learning resources. The…

Perspectives on the Development and Future of Advanced Placement® Human Geography

ERIC Educational Resources Information Center

Hildebrant, Barbara

2016-01-01

Advanced Placement (AP) Human Geography faced a number of hurdles that nearly derailed the course before it launched in 2000-2001. A dedicated cadre of geography professionals and high school teachers rose to the challenge and the course remains one of the fastest growing AP courses currently offered by College Board. Seventeen readers and leaders…

AN ADVANCED PLACEMENT COURSE IN ANALYTIC GEOMETRY AND CALCULUS (MATHEMATICS XV X AP).

ERIC Educational Resources Information Center

DEROLF, JOHN J.; MIENTKA, WALTER E.

THIS TEXT ON ANALYTIC GEOMETRY AND CALCULUS IS A CORRESPONDENCE COURSE DESIGNED FOR ADVANCED PLACEMENT OF HIGH SCHOOL STUDENTS IN COLLEGE. EACH OF THE 21 LESSONS INCLUDES READING ASSIGNMENTS AND LISTS OF PROBLEMS TO BE WORKED. IN ADDITION, SUPPLEMENTARY EXPLANATIONS AND COMMENTS ARE INCLUDED THAT (1) PROVIDE ILLUSTRATIVE EXAMPLES OF CONCEPTS AND…

Student Participation and Performance on Advanced Placement Exams: Do State-Sponsored Incentives Make a Difference?

ERIC Educational Resources Information Center

Jeong, Dong Wook

2009-01-01

Many states provide incentives to students, teachers, and schools for the participation and success of students on Advanced Placement (AP) examinations administered by the College Board. The purpose of this article is to examine whether these incentives help students enroll and succeed in AP exams. An analysis of nationally representative AP exam…

Advanced Placement English Exam Scores: A Comparison of Scores for Hispanic Students from California, Texas, and Arizona

ERIC Educational Resources Information Center

Koch, Bevan; Slate, John R.; Moore, George W.

2016-01-01

We compared the performance of Hispanic students from California, Texas, and Arizona on the two Advanced Placement (AP) English exams (i.e., English Language and Composition and English Literature and Composition) using archival data from the College Board from 1997 through 2012. Pearson chi-square tests yielded statistically significant…

High School Advanced Placement and Student Performance in College: STEM Majors, Non-STEM Majors, and Gender Differences

ERIC Educational Resources Information Center

Ackerman, Phillip L.; Kanfer, Ruth; Calderwood, Charles

2013-01-01

Background/Context: The past few decades have seen an explosive growth in high-school student participation in the Advanced Placement program® (AP), with nearly two million exams completed in 2011. Traditionally, universities have considered AP enrollment as an indicator for predicting academic success during the admission process. However, AP…

Having the AP Conversation: Why It's Time to Re-Evaluate Advanced Placement Courses

ERIC Educational Resources Information Center

Weaver, Roger

2010-01-01

Since its widespread emergence in the mid-1960s, the Advanced Placement (AP) curriculum has successfully established and maintained an identity as the gold standard of transcript currency for college preparatory schools. It is something that nearly all independent school parents and students believe they understand and clearly expect, and it is…

The Effect of Advanced Placement or International Baccalaureate Exam Scores upon College GPA and College Choice

ERIC Educational Resources Information Center

Farmer, Daniel Raymond

2017-01-01

This quantitative, causal-comparative and correlational study analyzed students' academic performance in college based on whether the student was classified as an International Baccalaureate student, an Advanced Placement student, or a non-accelerated student (those who did not participate in IB or AP) and how that choice of academic program…

Effectiveness of Selected Advanced Placement Programs on the Academic Performance and College Readiness of High School Students

ERIC Educational Resources Information Center

Lewis, Traschell S.

2012-01-01

The purpose of this study was to examine the effectiveness of selected Advanced Placement (AP) programs on the academic performance and college readiness of high school students. Specifically, the researcher was concerned with ascertaining the effectiveness of social science, math, science, English, music/art and language AP programs on the…

Advanced Placement in Studio Art and Secondary Art Education Policy: Countering the Null Curriculum

ERIC Educational Resources Information Center

Graham, Mark A.; Sims-Gunzenhauser, Alice

2009-01-01

Because of education reform policy and misconceptions about artistry and artistic assessment, visual art education remains in the margins of high school education. One response to the lack of supportive arts education policy is the Advanced Placement (AP) Studio Art Program, a visual arts assessment at the high school level that engages large…

TEACHERS' GUIDES. WORLD HISTORY FOR THE ACADEMICALLY TALENTED. ADVANCED PLACEMENT EUROPEAN HISTORY.

ERIC Educational Resources Information Center

AUGSPURGER, EVERETT F.; AND OTHERS

PREPARED BY TEACHERS AND SUPERVISORS WORKING WITH A 2-YEAR DEMONSTRATION PROJECT, THIS DOCUMENT CONTAINS GUIDES FOR A WORLD HISTORY COURSE (PREHISTORY TO EARLY 20TH CENTURY) FOR THE GIFTED AND AN ADVANCED PLACEMENT COURSE IN EUROPEAN HISTORY (ANCIENT CIVILIZATION TO EARLY 20TH CENTURY). STUDENTS ARE EXPECTED TO STUDY HISTORICAL ISSUES AND DEVELOP…

Advanced Placement versus Dual Enrollment: Making the Best Choice for College Selection, Persistence, Early Success, and Time to Completion

ERIC Educational Resources Information Center

Gruman, Daniel H.

2013-01-01

A substantial amount of research examines the benefits of high school college-credit attainment programs against non-participation. The growth in popularity of these programs, particularly Advanced Placement (AP) and dual enrollment (DE), has them competing against one another for student attention. However, students, schools, and policymakers do…

A Lesson Plan for Advanced Placement Human Geography®: A Site Location Exercise for New Businesses

ERIC Educational Resources Information Center

Poleski, Matthew

2017-01-01

The lesson described in this article meets several needs for Advanced Placement Human Geography (APHG®) teachers. In the interest of preserving time in the classroom, this lesson is intended to be a capstone assignment, allowing students to synthesize several concepts of the APHG® curriculum, such as demography, economic development, and cultural…

The Challenge of Advanced Placement Partnerships in the South Texas Border Classroom

ERIC Educational Resources Information Center

Blackwell, Deborah L.; Pisani, Jana S.; Pisani, Michael J.

2007-01-01

In the year 2000, the Texas Education Agency and the Texas A&M University System teamed up to create an initiative called the University Faculty Fellows Program. Spearheaded by Texas A&M International University in Laredo, the program paired up faculty from the university with area Advanced Placement (AP) teachers in a variety of…

Class of 2015 Advanced Placement and International Baccalaureate Exam Participation and Performance. Memorandum

ERIC Educational Resources Information Center

Navarro, Maria V.

2016-01-01

This memorandum describes the Advanced Placement (AP) and International Baccalaureate (IB) exams participation and performance of 2013 to 2015 public school graduates in Montgomery County Public Schools (MCPS) and the state of Maryland. The results are disaggregated by demographics and high schools. Students in the MCPS Class of 2015 continued to…

Advanced Placement and International Baccalaureate Examination Results in Texas, 2009-10. Document No. GE11 601 07

ERIC Educational Resources Information Center

Texas Education Agency, 2011

2011-01-01

This report reviews Advanced Placement (AP) and International Baccalaureate (IB) examination participation and performance in Texas during the 2009-10 school year. Campus-, district-, and state-level examination results for students in Texas public schools are presented, as well as state-level examination results for students in Texas public and…

Students' Perceptions of the Social/Emotional Implications of Participation in Advanced Placement and International Baccalaureate Programs. Research Monograph Series. RM09238

ERIC Educational Resources Information Center

Foust, Regan Clark; Hertberg-Davis, Holly; Callahan, Carolyn M.

2009-01-01

Using qualitative methods, the researchers explored student perceptions of the social and emotional advantages and disadvantages of Advanced Placement (AP) and International Baccalaureate (IB) program participation, differences between the AP and IB programs in those perceptions, and whether or not students report experiencing a "forced-choice…

Placing Advanced Placement® Human Geography: Its Role in U.S. Geography Education

ERIC Educational Resources Information Center

Bednarz, Sarah Witham

2016-01-01

This article examines Advanced Placement Human Geography (AP HG) in the context of its place in efforts to reform geography education. It presents a critical analysis of the AP program and its curriculum, asserting that it represents "powerful knowledge" as conceptualized by Young. It concludes with a call for research in AP HG aligned…

ISAAC - A Testbed for Advanced Composites Research

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey; Stewart, Brian K.; Martin, Robert A.

2014-01-01

The NASA Langley Research Center is acquiring a state-of-art composites fabrication environment to support the Center's research and technology development mission. This overall system described in this paper is named ISAAC, or Integrated Structural Assembly of Advanced Composites. ISAAC's initial operational capability is a commercial robotic automated fiber placement system from Electroimpact, Inc. that consists of a multi-degree of freedom commercial robot platform, a tool changer mechanism, and a specialized automated fiber placement end effector. Examples are presented of how development of advanced composite materials, structures, fabrication processes and technology are enabled by utilizing the fiber placement end effector directly or with appropriate modifications. Alternatively, end effectors with different capabilities may either be bought or developed with NASA's partners in industry and academia.

Eclipse - tow flight closeup and release

NASA Technical Reports Server (NTRS)

1998-01-01

This clip, running 15 seconds in length, shows the QF-106 'Delta Dart' gear down, with the tow rope secured to the attachment point above the aircraft nose. First there is a view looking back from the C-141A, then looking forward from the nose of the QF-106, and finally a shot of the aircraft being released from the tow rope. NASA Dryden Flight Research Center, Edwards, California, supported a Kelly Space and Technology, Inc. (KST)/U.S. Air Force project known as Eclipse, which demonstrated a reusable tow launch vehicle concept. The purpose of the project was to demonstrate a reusable tow launch vehicle concept that had been conceived and patented by KST. Kelly Space obtained a contract with the USAF Research Laboratory for the tow launch demonstration project under the Small Business Innovation Research (SBIR) program. The USAF SBIR contract included the modifications to turn the QF-106 into the Experimental Demonstrator #1 (EXD-01), and the C141A aircraft to incorporate the tow provisions to link the two aircraft, as well as conducting flight tests. The demonstration consisted of ground and flight tests. These tests included a Combined Systems Test of both airplanes joined by a tow rope, a towed taxi test, and six towed flights. The primary goal of the project was demonstrating the tow phase of the Eclipse concept using a scaled-down tow aircraft (C-141A) and a representative aerodynamically-shaped aircraft (QF-106A) as a launch vehicle. This was successfully accomplished. On December 20, 1997, NASA research pilot Mark Stucky flew a QF-106 on the first towed flight behind an Air Force C-141 in the joint Eclipse project with KST to demonstrate a reusable tow launch vehicle concept developed by KST. Kelly Space and Technology hoped to use the data from the tow tests to validate a tow-to-launch procedure for reusable space launch vehicles. Stucky flew six successful tow tests between December 1997 and February 6, 1998. On February 6, 1998, the sixth and final towed flight brought the project to a successful completion. Preliminary flight results determined that the handling qualities of the QF-106 on tow were very stable; actual flight-measured values of tow rope tension were well within predictions made by the simulation, aerodynamic characteristics and elastic properties of the tow rope were a significant component of the towing system; and the Dryden high-fidelity simulation provided a representative model of the performance of the QF-106 and C-141A airplanes in tow configuration. Total time on tow for the entire project was 5 hours, 34 minutes, and 29 seconds. All six flights were highly productive, and all project objectives were achieved. All three of the project objectives were successfully accomplished. The objectives were: demonstration of towed takeoff, climb-out, and separation of the EXD-01 from the towing aircraft; validation of simulation models of the towed aircraft systems; and development of ground and flight procedures for towing and launching a delta-winged airplane configuration safely behind a transport-type aircraft. NASA Dryden served as the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden also supplied engineering, simulation, instrumentation, range support, research pilots, and chase aircraft for the test series. Dryden personnel also performed the modifications to convert the QF-106 into the piloted EXD-01 aircraft. During the early flight phase of the project, Tracor, Inc. provided maintenance and ground support for the two QF-106 airplanes.The Air Force Flight Test Center (AFFTC), Edwards, California, provided the C-141A transport aircraft for the project, its flight and engineering support, and the aircrew. Kelly Space and Technology provided the modification design and fabrication of the hardware that was installed on the EXD-01 aircraft. Kelly Space and Technology hopes to use the data gleaned from the tow tests to develop a series of low-cost reusable launch vehicles, in particular to gain experience towing delta-wing aircraft having high wing loading, and in general to demonstrate various operational procedures such as ground processing and abort scenarios. The first successful towed flight occurred on Dec. 20, 1997. Prior to this first tow test flight, the C-141A and EXD-01 were used to conduct a series of tethered taxi tests to validate the tow procedures. Before these tethered taxi tests, a successful joint flight test was conducted in late October 1996, by Dryden, AFFTC, and KST, in which one of the Dryden F-18 chase aircraft flew at various ranges and locations behind the C-141A to define the wake turbulence and wingtip vortex environment. This flight test was replicated in July 1997, with an unmodified QF-106 flight proficiency aircraft.

Outcome and risk factors assessment for adverse events in advanced esophageal cancer patients after self-expanding metal stents placement.

PubMed

Rodrigues-Pinto, E; Pereira, P; Coelho, R; Andrade, P; Ribeiro, A; Lopes, S; Moutinho-Ribeiro, P; Macedo, G

2017-02-01

Self-expanding metal stents (SEMS) are the treatment of choice for advanced esophageal cancers. Literature is scarce on risk factors predictors for adverse events after SEMS placement. Assess risk factors for adverse events after SEMS placement in advanced esophageal cancer and evaluate survival after SEMS placement. Cross-sectional study of patients with advanced esophageal cancer referred for SEMS placement, during a period of 3 years. Ninety-seven patients with advanced esophageal cancer placed SEMS. Adverse events were more common when tumors were located at the level of the distal esophagus/cardia (47% vs 23%, P = 0.011, OR 3.1), with statistical significance being kept in the multivariate analysis (OR 3.1, P = 0.018). Time until adverse events was lower in the tumors located at the level of the distal esophagus/cardia (P = 0.036). Survival was higher in patients who placed SEMS with curative intent (327 days [126-528] vs. 119 days [91-147], P = 0.002) and in patients submitted subsequently to surgery compared with those who did just chemo/radiotherapy or who did not do further treatment (563 days [378-748] vs. 154 days [133-175] vs. 46 days [20-72], P < 0.001). Subsequent treatment kept statistical significance in the multivariate analysis (HR 3.4, P < 0.001). SEMS allow palliation of dysphagia in advanced esophageal cancer and are associated with an increased out-of-hospital survival, as long as there are conditions for further treatments. Tumors located at the level of the distal esophagus/cardia are associated with a greater number of adverse events, which also occur earlier. © 2016 International Society for Diseases of the Esophagus.

Eclipse takeoff and flight

NASA Technical Reports Server (NTRS)

1998-01-01

This 25-second clip shows the QF-106 'Delta Dart' tethered to the USAF C-141A during takeoff and in flight. NASA Dryden Flight Research Center, Edwards, California, supported a Kelly Space and Technology, Inc. (KST)/U.S. Air Force project known as Eclipse, which demonstrated a reusable tow launch vehicle concept. The purpose of the project was to demonstrate a reusable tow launch vehicle concept that had been conceived and patented by KST. Kelly Space obtained a contract with the USAF Research Laboratory for the tow launch demonstration project under the Small Business Innovation Research (SBIR) program. The USAF SBIR contract included the modifications to turn the QF-106 into the Experimental Demonstrator #1 (EXD-01), and the C141A aircraft to incorporate the tow provisions to link the two aircraft, as well as conducting flight tests. The demonstration consisted of ground and flight tests. These tests included a Combined Systems Test of both airplanes joined by a tow rope, a towed taxi test, and six towed flights. The primary goal of the project was demonstrating the tow phase of the Eclipse concept using a scaled-down tow aircraft (C-141A) and a representative aerodynamically-shaped aircraft (QF-106A) as a launch vehicle. This was successfully accomplished. On December 20, 1997, NASA research pilot Mark Stucky flew a QF-106 on the first towed flight behind an Air Force C-141 in the joint Eclipse project with KST to demonstrate the reusable tow launch vehicle concept developed by KST. Kelly hoped to use the data from the tow tests to validate a tow-to-launch procedure for reusable space launch vehicles. Stucky flew six successful tow tests between December 1997 and February 6, 1998. On February 6, 1998, the sixth and final towed flight brought the project to a successful completion. Preliminary flight results determined that the handling qualities of the QF-106 on tow were very stable; actual flight measured values of tow rope tension were well within predictions made by the simulation, aerodynamic characteristics and elastic properties of the tow rope were a significant component of the towing system; and the Dryden high-fidelity simulation provided a representative model of the performance of the QF-106 and C-141A airplanes in tow configuration. Total time on tow for the entire project was 5 hours, 34 minutes, and 29 seconds. All six flights were highly productive, and all project objectives were achieved. All three of the project objectives were successfully accomplished. The objectives were: demonstration of towed takeoff, climb-out, and separation of the EXD-01 from the towing aircraft; validation of simulation models of the towed aircraft systems; and development of ground and flight procedures for towing and launching a delta-winged airplane configuration safely behind a transport-type aircraft. NASA Dryden served as the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden also supplied engineering, simulation, instrumentation, range support, research pilots, and chase aircraft for the test series. Dryden personnel also performed the modifications to convert the QF-106 into the piloted EXD-01 aircraft. During the early flight phase of the project, Tracor, Inc. provided maintenance and ground support for the two QF-106 airplanes. The Air Force Flight Test Center (AFFTC), Edwards, California, provided the C-141A transport aircraft for the project, its flight and engineering support, and the aircrew. Kelly Space and Technology provided the modification design and fabrication of the hardware that was installed on the EXD-01 aircraft. Kelly Space and Technology hopes to use the data gleaned from the tow tests to develop a series of low-cost reusable launch vehicles, in particular to gain experience towing delta-wing aircraft having high wing loading, and in general to demonstrate various operational procedures such as ground processing and abort scenarios. The first successful towed flight occurred on December 20, 1997. Prior to this first tow test flight, the C-141A and EXD-01 were used to conduct a series of tethered taxi tests that would validate the tow procedures. Before these tethered taxi tests, a successful joint flight test was conducted in late October 1996, by Dryden, AFFTC, and KST, in which one of the Dryden F-18 chase aircraft flew at various ranges and locations behind the C-141A to define the wake turbulence and wingtip vortex environment. This flight test was replicated in July 1997, with an unmodified QF-106 flight proficiency aircraft.

34 CFR 379.30 - What selection criteria does the Secretary use under this program?

Code of Federal Regulations, 2010 CFR

2010-07-01

... private industry in the planning, implementation, and evaluation of job development, job placement, career... identification of job and career opportunities within the community, consistent with the current and projected... placement programs designed to identify and develop job placement and career advancement opportunities. (3...

Carbon fiber reinforcements for sheet molding composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ozcan, Soydan; Paulauskas, Felix L.

A method of processing a carbon fiber tow includes the steps of providing a carbon fiber tow made of a plurality of carbon filaments, depositing a sizing composition at spaced-apart sizing sites along a length of the tow, leaving unsized interstitial regions of the tow, and cross-cutting the tow into a plurality of segments. Each segment includes at least a portion of one of the sizing sites and at least a portion of at least one of the unsized regions of the tow, the unsized region including and end portion of the segment.

Stereotype Threat? Male and Female Students in Advanced High School Courses

NASA Astrophysics Data System (ADS)

Corra, Mamadi

Propositions of stereotype threat theory imply that the social consequences of academic distinction in advanced quantitative areas (such as math and the physical sciences) for women may promote the under representation of female students in advanced quantitative academic courses. The hypothesis that female students will be underrepresented in advanced quantitative (honors and advanced placement math and physical science) courses is tested using academic performance and enrollment data for high school students in a "Student/Parent Informed Choice" (open registration) school district in North Carolina. Results show female students to be overrepresented in both advanced verbal/writing intensive (honors and advanced placement English, foreign language, and social science) and advanced quantitative (honors and advanced placement math and physical science) courses compared to their proportion of the student body. More surprisingly, results also indicate female students (compared to male students) to be overrepresented in advanced courses compared to their proportion of high-performing students. Furthermore, as with patterns observed at the district level, additional analysis of enrollment data for the entire state reveals similar results. Taken together, the findings call into question the prevailing presumption that female students continue to be underrepresented in math and physical science courses. Instead, the changing social context within which females and males experience schooling may provide an explanation for the findings.

Implementing the Constructed Scaffold Model: Hands-On Activity Units for Advanced Placement Calculus

ERIC Educational Resources Information Center

Scott, Susan

2017-01-01

The purpose of the present action research study is to describe a hands-on activity model, named the Constructed Scaffold Model (CSM), used in an Advanced Placement Calculus class in a southeastern United States suburban high school. Data were collected over an 8-week period during the spring 2017 semester. The teacher-researcher developed a…

Number of Schools Offering AP Falls after First Audit of Courses

ERIC Educational Resources Information Center

Cech, Scott J.

2007-01-01

This article reports the findings of the first audit of Advanced Placement (AP) courses. One of the more striking effects of the audit, the results of which were released recently by the College Board, was a steep drop in the number of schools offering Advanced Placement courses. After more than 30 years of steady growth, the number of schools…

Advanced Placement Human Geography and the Annual Meetings of the National Council for Geographic Education

ERIC Educational Resources Information Center

Sublett, Michael D.

2007-01-01

Members of the National Council for Geographic Education have been instrumental in the creation, launch, and early success of Advanced Placement Human Geography. Annual meetings of the Council have served as a forum for spreading the word about the course and its follow-up national examination and in helping teachers develop content confidence and…

The Advanced Placement Program Benefits Mainly Well-Prepared Students Who Pass AP Exams. Issues in College Readiness

ERIC Educational Resources Information Center

National Center for Educational Achievement, 2010

2010-01-01

Many policymakers and education leaders have embraced the Advanced Placement (AP) Program as a tool to strengthen the high school curriculum and prepare students for college. The popularity of the AP program among these policy leaders reflects their belief that the traditional high school curriculum has often failed to provide rigorous courses…

A Phenomenological Study of How High School Advanced Placement Classes Prepared First-Generation College Students for Postsecondary Education

ERIC Educational Resources Information Center

Snyder, Scott

2013-01-01

This study investigated the lived experiences of first-generation college students and the perceived influence of taking high school Advanced Placement (AP) courses on their college education. The following research questions were addressed: (a) what motivated students to consider going to college, (b) what was their experience in taking AP…

A Study of Gender and Performance on Advanced Placement History Examinations. College Board Report No. 91-4.

ERIC Educational Resources Information Center

Breland, Hunter M.; And Others

Several studies have shown that, on average, women perform slightly better than men on free-response tests, while men perform slightly better on multiple-choice tests. Two advanced placement examinations, United States History (USH) and European History (EH), were chosen for study because previous studies have shown that sex differences on the…

The Advanced Placement Program in Pennsylvania: Implications for Policy and Practice in K-12 and Higher Education

ERIC Educational Resources Information Center

Liekar, Christine Y.

2012-01-01

Since the time of Sputnik, American educators and policymakers have recognized the need to raise expectations by increasing rigor in high schools across the United States. Copious studies attest to the fact that students who take Advanced Placement coursework experience success in college (Adelman, 1999; Camara, 2003; College Board, 2005;…

Academic Preparedness and College Preparation Efforts: A Comparative Analysis of Perception of High School Advanced Placement Teachers and College Admissions Personnel

ERIC Educational Resources Information Center

Driver, Jason Hughes

2014-01-01

This study examines the relationship between high school efforts at post-secondary preparation for college bound students and the expectations of college and university admissions personnel. The Advanced Placement (AP) teachers and administrators at a rural Northwest Florida high school were administered a quantitative survey in order to collect…

The Rigor Mortis of Education: Rigor Is Required in a Dying Educational System

ERIC Educational Resources Information Center

Mixon, Jason; Stuart, Jerry

2009-01-01

In an effort to answer the "Educational Call to Arms", our national public schools have turned to Advanced Placement (AP) courses as the predominate vehicle used to address the lack of academic rigor in our public high schools. Advanced Placement is believed by many to provide students with the rigor and work ethic necessary to…

The Oral Histories of Six African American Males in Their Ecology of Advanced Placement Biology

ERIC Educational Resources Information Center

Halasa, Katrina Bassam

2012-01-01

The major purpose of this qualitative study was to examine the past in order to understand the complex phenomenon of students engaging in science (Newman, Ridenour, Newman, & DeMarco, 2003) specifically through the oral histories of six self-identified African American males enrolled in a high school Advanced Placement Biology class and the…

What Does a Student Know Who Earns a Top Score on the Advanced Placement Chemistry Exam?

ERIC Educational Resources Information Center

Claesgens, Jennifer; Daubenmire, Paul L.; Scalise, Kathleen M.; Balicki, Scott; Gochyyev, Perman; Stacy, Angelica M.

2014-01-01

This paper compares the performance of students at a high-performing U.S. public school (n = 64) on the advanced placement (AP) chemistry exam to their performance on the ChemQuery assessment system. The AP chemistry exam was chosen because, as the National Research Council acknowledges, it is the "perceived standard of excellence and school…

Snatching Defeat from the Jaws of Victory: When Good Projects Go Bad. Girls and Computer Science.

ERIC Educational Resources Information Center

Sanders, Jo

In week-long semesters in the summers of 1997, 1998, and 1999, the 6APT (Summer Institute in Computer Science for Advanced Placement Teachers) project taught 240 high school teachers of Advanced Placement Computer Science (APCS) about gender equity in computers. Teachers were then followed through 2000. Results indicated that while teachers, did…

An Investigation of College Students' Perceptions of Advanced Placement® Courses. Research Note 2013-2

ERIC Educational Resources Information Center

Cooney, Siobhan M.; McKillip, Mary E. M.; Smith, Kara

2013-01-01

The present study investigates how current college students perceive their experiences in high school Advanced Placement Program (AP) courses. The goal of this research was twofold: We wanted to not only add to the existing literature on outcomes for AP students but also investigate possible benefits for students without success (i.e., a score of…

Class of 2014 Advanced Placement and International Baccalaureate Exam Participation and Performance. Memorandum

ERIC Educational Resources Information Center

Sanderson, Geoffrey T.

2015-01-01

Beginning in 2006, Maryland has led the nation as the state with the highest percentage of graduates who earned one or more Advanced Placement (AP) exam scores of 3 or higher. Students in the Montgomery County (Maryland) Public Schools (MCPS) Class of 2014 continued to outperform students in the state of Maryland on AP examinations based on AP…

Class of 2012 Advanced Placement and International Baccalaureate Exam Participation and Performance. Memorandum

ERIC Educational Resources Information Center

Marks, Susan F.

2013-01-01

Students in the Montgomery County (Maryland) Public Schools (MCPS) Class of 2012 continued to outperform Maryland and the nation on Advanced Placement (AP) examinations based on the "AP Report to the Nation" released by the College Board on February 20, 2013. In 2012, 67.3 percent of MCPS graduates took one or more AP exams. A striking…

Directional Stability of Towed Airplanes

NASA Technical Reports Server (NTRS)

Soehne, W.

1956-01-01

So far, very careful investigations have been made regarding the flight properties, in particular the static and dynamic stability, of engine-propelled aircraft and of untowed gliders. In contrast, almost no investigations exist regarding the stability of airplanes towed by a towline. Thus, the following report will aim at investigating the directional stability of the towed airplane and, particularly, at determining what parameters of the flight attitude and what configuration properties affect the stability. The most important parameters of the flight attitude are the dynamic pressure, the aerodynamic coefficients of the flight attitude, and the climbing angle. Among the configuration properties, the following exert the greatest influence on the stability: the tow-cable length, the tow-cable attachment point, the ratio of the wing loadings of the towing and the towed airplanes, the moments of inertia, and the wing dihedral of the towed airplane. In addition, the size and shape of the towed airplane vertical tail, the vertical tail length, and the fuselage configuration are decisive factors in determining the yawing moment and side force due to sideslip, respectively.

Measurement of the Forces Acting on Gliders in Towed Flight

NASA Technical Reports Server (NTRS)

Klenperer, W B

1940-01-01

The magnitude, the direction, and the fluctuations of tow forces exerted upon gliders by towing them aloft behind an automobile were measured under a variety of conditions covering a range from gentle to severe types of operation. For these tests, the glider towing force did not exceed 1.6 of the gross weight of the glider. V-G records obtained during the towed-flight period as well as during the subsequent return glide to earth showed accelerations in the range from 3 to -1 g. The results of preliminary airplane tow tests are also presented.

Advancing Prediction of Foster Placement Disruption Using Brief Behavioral Screening

ERIC Educational Resources Information Center

Hurlburt, Michael S.; Chamberlain, Patricia; DeGarmo, David; Zhang, Jinjin; Price, Joe M.

2010-01-01

Objective: Behavioral difficulties increase the risk that children will experience negative placement disruptions while in foster care. Chamberlain et al. (2006) found that the Parent Daily Report (PDR), a brief measure of parent-reported child behaviors, was a strong predictor of negative placement changes over 1 year among children receiving…

Automatic Correction of Adverb Placement Errors for CALL

ERIC Educational Resources Information Center

Garnier, Marie

2012-01-01

According to recent studies, there is a persistence of adverb placement errors in the written productions of francophone learners and users of English at an intermediate to advanced level. In this paper, we present strategies for the automatic detection and correction of errors in the placement of manner adverbs, using linguistic-based natural…

Biliary intraductal metastasis from advanced gastric cancer: radiologic and histologic characteristics, and clinical outcomes of percutaneous metallic stent placement.

PubMed

Lee, JooYeon; Gwon, Dong Il; Ko, Gi-Young; Kim, Jong Woo; Sung, Kyu-Bo

2016-06-01

To investigate the radiologic and histological characteristics of biliary intraductal metastasis of advanced gastric cancer and the clinical outcomes of percutaneous, metallic stent placement. We retrospectively assessed 24 patients with obstructive jaundice related to biliary intraductal metastasis of gastric cancers who underwent PTBD and subsequent metallic stent placement between 2003 and 2012. Intraductal metastases appeared as uniform, concentric, linear (n = 17) or band-like (n = 7), enhanced wall thickening on CT, and 20 patients (83.3 %) had cystic ductal lesions. On pathology specimens, malignant cells scattered in the submucosal layer caused a desmoplastic reaction. The technical and clinical success rate of stent placement was achieved in all 24 patients. The median survival time was 203 days. Stent occlusion was observed in four patients with 49-278 days following stent placement. The median stent patency time was 156 days. The radiologic and histological characteristics of biliary intraductal metastasis of advanced gastric cancer consist of uniform, linear or band-like, enhanced biliary wall thickening and malignant cells scattered in the submucosal layer, together with the desmoplastic reaction without any disruption of the epithelial layer. Uncovered metallic stent placement was also a safe and effective method of palliative treatment in these patients. • The CT findings of intraductal metastasis were linear/band-like, enhanced biliary wall thickening. • The histological finding was malignant cells scattered in the submucosal layer. • It showed a desmoplastic reaction without any disruption of the epithelial layer. • Uncovered metallic stent placement was a safe and effective palliative treatment.

Advanced high school biology in an era of rapid change: a summary of the biology panel report from the NRC Committee on Programs for Advanced Study of Mathematics and Science in American High Schools.

PubMed

Wood, William B

2002-01-01

A recently released National Research Council (NRC) report, Learning and Understanding: Improving Advanced Study of Mathematics and Science in U.S. High Schools, evaluated and recommended changes in the Advanced Placement (AP), International Baccalaureate (IB), and other advanced secondary school science programs. As part of this study, discipline-specific panels were formed to evaluate advanced programs in biology, chemistry, physics, and mathematics. Among the conclusions of the Content Panel for Biology were that AP courses in particular suffer from inadequate quality control as well as excessive pressure to fulfill their advanced placement function, which encourages teachers to attempt coverage of all areas of biology and emphasize memorization of facts rather than in-depth understanding. In this essay, the Panel's principal findings are discussed, with an emphasis on its recommendation that colleges and universities should be strongly discouraged from using performance on either the AP examination or the IB examination as the sole basis for automatic placement out of required introductory courses for biology majors and distribution requirements for nonmajors.

Advanced High School Biology in an Era of Rapid Change: A Summary of the Biology Panel Report from the NRC Committee on Programs for Advanced Study of Mathematics and Science in American High Schools

PubMed Central

2002-01-01

A recently released National Research Council (NRC) report, Learning and Understanding: Improving Advanced Study of Mathematics and Science in U.S. High Schools, evaluated and recommended changes in the Advanced Placement (AP), International Baccalaureate (IB), and other advanced secondary school science programs. As part of this study, discipline-specific panels were formed to evaluate advanced programs in biology, chemistry, physics, and mathematics. Among the conclusions of the Content Panel for Biology were that AP courses in particular suffer from inadequate quality control as well as excessive pressure to fulfill their advanced placement function, which encourages teachers to attempt coverage of all areas of biology and emphasize memorization of facts rather than in-depth understanding. In this essay, the Panel's principal findings are discussed, with an emphasis on its recommendation that colleges and universities should be strongly discouraged from using performance on either the AP examination or the IB examination as the sole basis for automatic placement out of required introductory courses for biology majors and distribution requirements for nonmajors. PMID:12669097

33 CFR 162.255 - Wrangell Narrows, Alaska; use, administration, and navigation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Channel Buoy 1 TC. East of Tow Channel Buoy 3 TC. West of Tow Channel Buoy 4 TC. East of Colorado Reef... Tow Channel Buoy 5 TC. East of Tow Channel Buoy 7 TC. West of Petersburg: East of Wrangell Narrows...

33 CFR 162.255 - Wrangell Narrows, Alaska; use, administration, and navigation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Channel Buoy 1 TC. East of Tow Channel Buoy 3 TC. West of Tow Channel Buoy 4 TC. East of Colorado Reef... Tow Channel Buoy 5 TC. East of Tow Channel Buoy 7 TC. West of Petersburg: East of Wrangell Narrows...

"Having It All" at Sleep's Expense: The Forced Choice of Participants in Advanced Placement Courses and International Baccalaureate Programs

ERIC Educational Resources Information Center

Foust, Regan Clark; Hertberg-Davis, Holly; Callahan, Carolyn M.

2008-01-01

The gifted can suffer from too many demands on their time and attention. This qualitative study tested the theory that advanced placement (AP) and international baccalaureate (IB) participants may feel forced to choose between academic success and social acceptance. The results, however, did not support the theory. Not only did gifted students not…

Advanced Placement Results, 2013-14. Measuring Up. D&A Report No.15.01

ERIC Educational Resources Information Center

Gilleland, Kevin; Muli, Juliana

2015-01-01

Advanced Placement (AP) outcomes for Wake County Public School System (WCPSS) students have continued an upward trend for over 18 years, out-performing the state and the nation in all measures. In 2013-14 there were 13,757 exams taken by 6,955 WCPSS test-takers with almost 76% of the exams resulting in scores at or above 3, outperforming Guilford…

Advanced Placement[R] Exam-Taking and Performance: Relationships with First-Year Subject Area College Grades. Research Report 2011-4

ERIC Educational Resources Information Center

Patterson, Brian F.; Packman, Sheryl; Kobrin, Jennifer L.

2011-01-01

The purpose of this study was to examine the effects of Advanced Placement[R] (AP[R]) exam participation and performance on college grades for courses taken in the same subject area as students' AP Exam(s). Students' first-year college subject area grade point averages (SGPAs) were examined in nine subject areas: mathematics, computer science,…

Filling a Plastic Bag with Carbon Dioxide: A Student-Designed Guided-Inquiry Lab for Advanced Placement and College Chemistry Courses

ERIC Educational Resources Information Center

Lanni, Laura M.

2014-01-01

A guided-inquiry lab, suitable for first-year general chemistry or high school advanced placement chemistry, is presented that uses only inexpensive, store-bought materials. The reaction of sodium bicarbonate (baking soda) with aqueous acetic acid (vinegar), under the constraint of the challenge to completely fill a sealable plastic bag with the…

Impact of Group Work and Extended Essay Writing on Online Advanced Placement Program® Student Performance. Research Report. ETS RR-07-22

ERIC Educational Resources Information Center

Handwerk, Phil

2007-01-01

Online high schools are growing significantly in number, popularity, and function. However, little empirical data has been published about the effectiveness of these institutions. This research examined the frequency of group work and extended essay writing among online Advanced Placement Program® (AP®) students, and how these tasks may have…

High School Students' Attitudes and Beliefs on Using the Science Writing Heuristic in an Advanced Placement Chemistry Class

ERIC Educational Resources Information Center

Putti, Alice

2011-01-01

This paper discusses student attitudes and beliefs on using the Science Writing Heuristic (SWH) in an advanced placement (AP) chemistry classroom. During the 2007 school year, the SWH was used in a class of 24 AP chemistry students. Using a Likert-type survey, student attitudes and beliefs on the process were determined. Methods for the study are…

Advanced Placement® Exam-Taking and Performance: Relationships with First-Year Subject Area College Grades. Research Report No. 2011-4

ERIC Educational Resources Information Center

Patterson, Brian F.; Packman, Sheryl; Kobrin, Jennifer L.

2011-01-01

The purpose of this study was to examine the effects of Advanced Placement (AP) exam participation and performance on college grades for courses taken in the same subject area as students' AP Exam(s). Students' first-year college subject area grade point averages (SGPAs) were examined in nine subject areas: mathematics, computer science,…

Class of 2013 Advanced Placement and International Baccalaureate Exam Participation and Performance. Memorandum

ERIC Educational Resources Information Center

Sanderson, Geoffrey T.

2014-01-01

Beginning in 2006, Maryland has led the nation as the state with the highest percentage of graduates who earned one or more Advanced Placement (AP) exam scores of 3 or higher. Students in the Montgomery County Public Schools (MCPS) Class of 2013 continued to outperform students in the state of Maryland and the nation on AP examinations, based on…

Evaluation of Unexploded Ordnance (UXO) Detection Technology at the Standardized UXO Test Sites Aberdeen and Yuma Proving Grounds

DTIC Science & Technology

2007-11-01

TTF Open Field (169) EM EM61MKII cart May. 2006 USGS Blind Grid (805) EM All TEM towed May. 2006 USGS Blind Grid (806) MAG TMGS towed 2.3-1 2.3...0.98 at YPG with a TMGS towed and an TM-4 sling system. f. The only ground penetrating radar system analyzed was demonstrated at the APG blind...MAG858/Cart(312) SCH/Hand(238) SCH/Hand(606) STOLS/Towed(293M) TM4/Sling(362) TM4/Sling(431) TMGS /Towed(806) EM61G822A/Cart(383D) STOLS/Towed(293D

Test report for 120-inch-diameter Solid Rocket Booster (SRB) model tests. [floating and towing characteristics of space shuttle boosters

NASA Technical Reports Server (NTRS)

Jones, W. C.

1973-01-01

The space shuttle solid rocket boosters (SRB's) will be jettisoned to impact in the ocean within a 200-mile radius of the launch site. Tests were conducted at Long Beach, California, using a 12-inch diameter Titan 3C model to simulate the full-scale characteristics of the prototype SRB during retrieval operations. The objectives of the towing tests were to investigate and assess the following: (1) a floating and towing characteristics of the SRB; (2) need for plugging the SRB nozzle prior to tow; (3) attach point locations on the SRB; (4) effects of varying the SRB configuration; (5) towing hardware; and (6) difficulty of attaching a tow line to the SRB in the open sea. The model was towed in various sea states using four different types and varying lengths of tow line at various speeds. Three attach point locations were tested. Test data was recorded on magnetic tape for the tow line loads and for model pitch, roll, and yaw characteristics and was reduced by computer to tabular printouts and X-Y plots. Profile and movie photography provided documentary test data.

Impact of advanced pharmacy practice experience placement changes in colleges and schools of pharmacy.

PubMed

Duke, Lori J; Staton, April G; McCullough, Elizabeth S; Jain, Rahul; Miller, Mindi S; Lynn Stevenson, T; Fetterman, James W; Lynn Parham, R; Sheffield, Melody C; Unterwagner, Whitney L; McDuffie, Charles H

2012-04-10

To document the annual number of advanced pharmacy practice experience (APPE) placement changes for students across 5 colleges and schools of pharmacy, identify and compare initiating reasons, and estimate the associated administrative workload. Data collection occurred from finalization of the 2008-2009 APPE assignments throughout the last date of the APPE schedule. Internet-based customized tracking forms were used to categorize the initiating reason for the placement change and the administrative time required per change (0 to 120 minutes). APPE placement changes per institution varied from 14% to 53% of total assignments. Reasons for changes were: administrator initiated (20%), student initiated (23%), and site/preceptor initiated (57%) Total administrative time required per change varied across institutions from 3,130 to 22,750 minutes, while the average time per reassignment was 42.5 minutes. APPE placements are subject to high instability. Significant differences exist between public and private colleges and schools of pharmacy as to the number and type of APPE reassignments made and associated workload estimates.

Strategies for Controlled Placement of Nanoscale Building Blocks

PubMed Central

2007-01-01

The capability of placing individual nanoscale building blocks on exact substrate locations in a controlled manner is one of the key requirements to realize future electronic, optical, and magnetic devices and sensors that are composed of such blocks. This article reviews some important advances in the strategies for controlled placement of nanoscale building blocks. In particular, we will overview template assisted placement that utilizes physical, molecular, or electrostatic templates, DNA-programmed assembly, placement using dielectrophoresis, approaches for non-close-packed assembly of spherical particles, and recent development of focused placement schemes including electrostatic funneling, focused placement via molecular gradient patterns, electrodynamic focusing of charged aerosols, and others. PMID:21794185

Where the girls aren't: High school girls and advanced placement physics enrollment

NASA Astrophysics Data System (ADS)

Barton, Susan O'brien

During the high school years, when many students first have some choice in course selection, research indicates that girls choose to enroll in more math and science courses, take more advanced placement courses, and take more honors courses in English, biology, chemistry, mathematics, and foreign languages than ever before. Yet, not only are boys more likely to take all of the three core science courses (biology, chemistry, and physics), boys enroll in advanced placement physics approximately three times as often as do girls. This study examines the perceptions, attitudes, and aspirations of thirty high school girls enrolled in senior-level science electives in an attempt to understand their high school science course choices, and what factors were influencing them. This is a qualitative investigation employing constructivist grounded theory methods. There are two main contributions of this study. First, it presents a new conceptual and analytical framework to investigate the problem of why some high school girls do not enroll in physics coursework. This framework is grounded in the data and is comprised of three existing feminist perspectives along the liberal/radical continuum of feminist thought. Second, this study illuminates a complex set of reasons why participants avoided high school physics (particularly advanced placement physics) coursework. These reasons emerged as three broad categories related to: (a) a lack of connectedness with physics curriculum and instruction; (b) prior negative experiences with physics and math classroom climates; and (c) future academic goals and career aspirations. Taken together, the findings of this study indicate that the problem of high school girls and physics enrollment---particularly advanced placement physics enrollment---is a problem that cannot be evaluated or considered from one perspective.

Job Placement Regimes in Europe: Trends and Impacts of Changes. IAB Labour Market Research Topics.

ERIC Educational Resources Information Center

Konle-Seidl, Regina; Walwei, Ulrich

Trends in job placement in Europe and the effects of advances in information and communication technologies on job placement practices were examined through case studies of France, Germany, the Netherlands, and the United Kingdom. The case studies revealed that the market shares of public employment services (PES) are generally higher than those…

Computerized Placement Management Software (CPMS): User Manual, Version 3.0.

ERIC Educational Resources Information Center

College Entrance Examination Board, Princeton, NJ.

This guide is designed to enable the beginner, as well as the advanced user, to understand and use the Computerized Placement Management Software (CPMS). The CPMS is a system for evaluating information about students and recommending their placement into courses best suited for them. It also tracks their progress and maintains their records. The…

Method of forming composite fiber blends

NASA Technical Reports Server (NTRS)

McMahon, Paul E. (Inventor); Chung, Tai-Shung (Inventor); Ying, Lincoln (Inventor)

1989-01-01

The instant invention involves a process used in preparing fibrous tows which may be formed into polymeric plastic composites. The process involves the steps of (a) forming a tow of strong filamentary materials; (b) forming a thermoplastic polymeric fiber; (c) intermixing the two tows; and (d) withdrawing the intermixed tow for further use.

46 CFR 15.910 - Towing vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Towing vessels. 15.910 Section 15.910 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Equivalents § 15.910 Towing vessels. No person may serve as a master or mate (pilot) of any towing vessel...

46 CFR 15.910 - Towing vessels.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Towing vessels. 15.910 Section 15.910 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Equivalents § 15.910 Towing vessels. No person may serve as a master or mate (pilot) of any towing vessel...

46 CFR 15.910 - Towing vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Towing vessels. 15.910 Section 15.910 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Equivalents § 15.910 Towing vessels. No person may serve as a master or mate (pilot) of any towing vessel...

46 CFR 15.910 - Towing vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Towing vessels. 15.910 Section 15.910 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Equivalents § 15.910 Towing vessels. No person may serve as a master or mate (pilot) of any towing vessel...

46 CFR 15.910 - Towing vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Towing vessels. 15.910 Section 15.910 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Equivalents § 15.910 Towing vessels. No person may serve as a master or mate (pilot) of any towing vessel...

32 CFR 634.50 - Towing and storage.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Towing and storage. 634.50 Section 634.50 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... Towing and storage. (a) Impounded POVs may be towed and stored by either the Services and DLA or a...

32 CFR 634.50 - Towing and storage.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 4 2014-07-01 2013-07-01 true Towing and storage. 634.50 Section 634.50 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... Towing and storage. (a) Impounded POVs may be towed and stored by either the Services and DLA or a...

32 CFR 634.50 - Towing and storage.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 4 2011-07-01 2011-07-01 false Towing and storage. 634.50 Section 634.50 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... Towing and storage. (a) Impounded POVs may be towed and stored by either the Services and DLA or a...

32 CFR 634.50 - Towing and storage.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 4 2013-07-01 2013-07-01 false Towing and storage. 634.50 Section 634.50 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... Towing and storage. (a) Impounded POVs may be towed and stored by either the Services and DLA or a...

Test and analysis results for composite transport fuselage and wing structures

NASA Technical Reports Server (NTRS)

Deaton, Jerry W.; Kullerd, Susan M.; Madan, Ram C.; Chen, Victor L.

1992-01-01

Automated tow placement (ATP) and stitching of dry textile composite preforms followed by resin transfer molding (RTM) are being investigated by researchers at NASA LaRC and Douglas Aircraft Company as cost-effective manufacturing processes for obtaining damage tolerant fuselage and wing structures for transport aircraft. The Douglas work is being performed under a NASA contract entitled 'Innovative Composites Aircraft Primary Structures (ICAPS)'. Data are presented in this paper to assess the damage tolerance of ATP and RTM fuselage elements with stitched-on stiffeners from compression tests of impacted three-J-stiffened panels and from stiffener pull-off tests. Data are also presented to assess the damage tolerance of RTM wing elements which had stitched skin and stiffeners from impacted single stiffener and three blade-stiffened compression tests and stiffener pull-off tests.

Assessing Competing Demands and Charting a Course: A Phenomenological Study of Advanced Placement U.S. History Teachers' Decision Making and Course Planning

ERIC Educational Resources Information Center

Poole, Kerry D.

2014-01-01

Florida has experienced some of the greatest growth of Advanced Placement (AP) programs in recent years and student scores on the AP exams have evolved into a highly significant metric in evaluating student proficiency and teacher and school effectiveness. Despite this growth, it is not well known how AP teachers make decisions about the content…

Are Advanced Placement English and First-Year College Composition Equivalent? A Comparison of Outcomes in the Writing of Three Groups of Sophomore College Students

ERIC Educational Resources Information Center

Hansen, Kristine; Reeve, Suzanne; Gonzalez, Jennifer; Sudweeks, Richard R.; Hatch, Gary L.; Esplin, Patricia; Bradshaw, William S.

2006-01-01

This study was conducted to obtain empirical data to inform policy decisions about exempting incoming students from a first-year composition (FYC) course on the basis of Advanced Placement (AP) English exam scores. It examined the effect of avoiding first-year writing on the writing abilities of sophomore undergraduates. Two three-page writing…

Method of forming composite fiber blends and molding same

NASA Technical Reports Server (NTRS)

McMahon, Paul E. (Inventor); Chung, Tai-Shung (Inventor)

1989-01-01

The instant invention involves a process used in preparing fibrous tows which may be formed into polymeric plastic composites. The process involves the steps of (a) forming a tow of strong filamentary materials; (b) forming a thermoplastic polymeric fiber; (c) intermixing the two tows; and (d) withdrawing the intermixed tow for further use.

49 CFR 392.63 - Towing or pushing loaded buses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 5 2010-10-01 2010-10-01 false Towing or pushing loaded buses. 392.63 Section 392... COMMERCIAL MOTOR VEHICLES Prohibited Practices § 392.63 Towing or pushing loaded buses. No disabled bus with... passengers aboard for the purpose of towing or pushing any disabled motor vehicle, except in such...

14 CFR 91.309 - Towing: Gliders and unpowered ultralight vehicles.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Towing: Gliders and unpowered ultralight... Flight Operations § 91.309 Towing: Gliders and unpowered ultralight vehicles. (a) No person may operate a civil aircraft towing a glider or unpowered ultralight vehicle unless— (1) The pilot in command of the...

14 CFR 91.309 - Towing: Gliders and unpowered ultralight vehicles.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Towing: Gliders and unpowered ultralight... Flight Operations § 91.309 Towing: Gliders and unpowered ultralight vehicles. (a) No person may operate a civil aircraft towing a glider or unpowered ultralight vehicle unless— (1) The pilot in command of the...

14 CFR 91.309 - Towing: Gliders and unpowered ultralight vehicles.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Towing: Gliders and unpowered ultralight... Flight Operations § 91.309 Towing: Gliders and unpowered ultralight vehicles. (a) No person may operate a civil aircraft towing a glider or unpowered ultralight vehicle unless— (1) The pilot in command of the...

14 CFR 91.309 - Towing: Gliders and unpowered ultralight vehicles.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Towing: Gliders and unpowered ultralight... Flight Operations § 91.309 Towing: Gliders and unpowered ultralight vehicles. (a) No person may operate a civil aircraft towing a glider or unpowered ultralight vehicle unless— (1) The pilot in command of the...

Running with horizontal pulling forces: the benefits of towing.

PubMed

Grabowski, Alena M; Kram, Rodger

2008-10-01

Towing, or running with a horizontal pulling force, is a common technique used by adventure racing teams. During an adventure race, the slowest person on a team determines the team's overall performance. To improve overall performance, a faster runner tows a slower runner with an elastic cord attached to their waists. Our purpose was to create and validate a model that predicts the optimal towing force needed by two runners to achieve their best overall performance. We modeled the effects of towing forces between two runners that differ in solo 10-km performance time and/or body mass. We calculated the overall time that could be saved with towing for running distances of 10, 20, and 42.2-km based on equations from previous research. Then, we empirically tested our 10-km model on 15 runners. Towing improved overall running performance considerably and our model accurately predicted this performance improvement. For example, if two runners (a 70 kg runner with a 35 min solo 10-km time and a 70-kg runner with a 50-min solo 10-km time) maintain an optimal towing force throughout a 10-km race, they can improve overall performance by 15%, saving almost 8 min. Ultimately, the race performance time and body mass of each runner determine the optimal towing force.

F-106 tow cable attachment and release mechanism for Eclipse program

NASA Technical Reports Server (NTRS)

1997-01-01

View of the tow cable attachment and release mechanism forward of the cockpit on the QF-106 Eclipse aircraft. This mechanism held and then released the Vectran rope used to tow the QF-106 behind an Air Force C-141A. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Effects of tow transit on the efficacy of the Chicago Sanitary and Ship Canal Electric Dispersal Barrier System

USGS Publications Warehouse

Davis, Jeremiah J.; LeRoy, Jessica Z.; Shanks, Matthew R.; Jackson, Patrick Ryan; Engel, Frank; Murphy, Elizabeth; Baxter, Carey L.; McInerney, Michael K.; Barkowski, Nicholas A.

2017-01-01

In 2016, the U.S. Fish and Wildlife Service, U.S. Geological Survey, and U.S. Army Corps of Engineers undertook a field study in the Chicago Sanitary and Ship Canal near Romeoville, Illinois to determine the influence of tow transit on the efficacy of the Electric Dispersal Barrier System (EDBS) in preventing the passage of juvenile fish (total length < 100 millimeters (mm)). Dual-frequency identification sonar data showed that large schools of juvenile fish (mean school size of 120 fish; n = 19) moved upstream and crossed the electric field of an array in the EDBS concurrent with downstream-bound (downbound) loaded tows in 89.5% of trials. Smaller schools of juvenile fish (mean school size of 98 fish; n = 15) moved downstream and crossed the electric field of an array in the EDBS concurrent with upstream-bound (upbound) loaded tows in 73.3% of trials. Observed fish passages through the EDBS were always opposite to the direction of tow movement, and not associated with propeller wash. These schools were not observed to breach the EDBS in the absence of a tow and showed no signs of incapacitation in the barrier during tow passage. Loaded tows transiting the EDBS create a return current of water flowing between the tow and the canal wall that typically travels opposite the direction of tow movement, and cause a decrease in the voltage gradient of the barrier of up to 88%. Return currents and decreases in voltage gradients induced by tow passage likely contributed to the observed fish passage through the EDBS. The efficacy of the EDBS in preventing the passage of small, wild fish is compromised while tows are moving across the barrier system. In particular, downbound tows moving through the EDBS create a pathway for the upstream movement of small fish, and therefore may increase the risk of transfer of invasive fishes from the Mississippi River Basin to the Great Lakes Basin.

The Value of Analysis of Standardized Placement Exams: A Case Study of Cell Structure.

ERIC Educational Resources Information Center

Blystone, Robert V.

This study focused on potential pedagological uses of standardized placement exams. A sample of 250 exams of the May 1984 Biology Advanced Placement (AP) exam was obtained and student responses to the question on cell structure were analyzed. The frequency of particular responses to the question is listed and trends and patterns in the responses…

Validating the Use of AP® Exam Scores for College Course Placement. Research Report 2013-2

ERIC Educational Resources Information Center

Patterson, Brian F.; Ewing, Maureen

2013-01-01

The Advanced Placement Program® (AP®) was created to provide access to rigorous, college-level curricula to motivated and prepared high school students. This study evaluated whether the AP Exam scores from the summative exams associated with 10 courses were valid for the placement of students into higher-level college courses in the subject area…

The Challenges of Using the WebCAPE Placement Exam in an Advanced Spanish Grammar Class

ERIC Educational Resources Information Center

Turner, Robert L., III

2017-01-01

This study attempts to ascertain if the WebCAPE placement exam can be used to measure improvement in an upper division grammar course. The WebCAPE online placement exam is a widely used instrument designed to help university language programs place students into the basic language course best corresponding to their proficiency level. This is done…

33 CFR 164.76 - Towline and terminal gear for towing alongside and pushing ahead.

Code of Federal Regulations, 2010 CFR

2010-07-01

... towing alongside and pushing ahead. 164.76 Section 164.76 Navigation and Navigable Waters COAST GUARD... Towline and terminal gear for towing alongside and pushing ahead. The owner, master, or operator of each vessel towing alongside or pushing ahead shall ensure that the face wires, spring lines, and push gear...

46 CFR 11.464 - Requirements for endorsements as master of towing vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Requirements for endorsements as master of towing....464 Requirements for endorsements as master of towing vessels. (a) If you would like to obtain an endorsement as master of towing vessels with a route listed in column 1 of table 11.464(a) of this section...

46 CFR 11.464 - Requirements for endorsements as master of towing vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Requirements for endorsements as master of towing....464 Requirements for endorsements as master of towing vessels. (a) If you would like to obtain an endorsement as master of towing vessels with a route listed in column 1 of table 11.464(a) of this section...

46 CFR 11.464 - Requirements for endorsements as master of towing vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Requirements for endorsements as master of towing....464 Requirements for endorsements as master of towing vessels. (a) If you would like to obtain an endorsement as master of towing vessels with a route listed in column 1 of table 11.464(a) of this section...

Prince William Sound disabled tanker towing study. Part 1. Evaluation of existing equipment, personnel and procedures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-08-01

The study has been undertaken by the Glosten Associates, Inc., to evaluate the existing capability for emergency towing at Prince William Sound and to examine alternatives that could enhance the escort and assist capabilities for disabled tankers within the waterway from the Alyeska Oil Terminal at the Port of Valdez to the Gulf of Alaska outside Hinchinbrook Entrance. Part 1, reported herein, is an objective evaluation by an experienced salvage towing master of the existing tugs, emergency towing equipment, towing practices, and discussion of alternative tug types.

High-Stakes and Non-Stakes Testing States and the Transfer of Knowledge to Students' Advanced Placement Test, Advanced Placement U.S. History Test, and SAT Exam Scores

ERIC Educational Resources Information Center

Lessler, Karen Jean

2010-01-01

The Federal education policy No Child Left Behind Act (NCLB) has initiated high-stakes testing among U.S. public schools. The premise of the NCLB initiative is that all students reach proficiency in reading and math by 2014. Under NCLB, individual state education departments were required to implement annual assessments in grades two through eight…

Preparing High School Students for Success in Advanced Placement Statistics: An Investigation of Pedagogies and Strategies Used in an Online Advanced Placement Statistics Course

ERIC Educational Resources Information Center

Potter, James Thomson, III

2012-01-01

Research into teaching practices and strategies has been performed separately in AP Statistics and in K-12 online learning (Garfield, 2002; Ferdig, DiPietro, Black & Dawson, 2009). This study seeks combine the two and build on the need for more investigation into online teaching and learning in specific content (Ferdig et al, 2009; DiPietro,…

A Comparison of the Number of Hours of Sleep in High School Students Who Took Advanced Placement and/or College Courses and Those Who Did Not

ERIC Educational Resources Information Center

Jin, Qiushuang; Shi, Qian

2008-01-01

This study investigated the association between sleep deprivation and enrollment in Advanced Placement (AP) and/or college courses among high school students. Approximately 4,000 surveys were distributed, and 2,197 completed surveys were returned from students in Grades 9 to 12 at 15 high schools in Iowa. Findings indicated the majority of high…

Architectures for High-Performance Ceramic Composites Being Improved

NASA Technical Reports Server (NTRS)

Yun, Hee Mann; DiCarlo, James A.

2002-01-01

A major thrust of the Ultra-Efficient Engine Technology (UEET) Program at the NASA Glenn Research Center is to develop advanced hot-section engine components using SiC/SiC ceramic matrix composites (CMC's) with thermostructural capability to 2400 F (1315 C). In previous studies, UEET determined that the higher the ultimate tensile strength (UTS) of the as-fabricated CMC, the greater its structural performance at 2400 F. Thus efforts have been ongoing within UEET to understand and develop fiber architecture approaches that can improve the UTS of SiC/SiC CMC's. Under UEET, SiC/SiC test panels and demonstration engine components are currently produced by the multi-ply layup of two-dimensional fabric pieces. The fabric is typically formed of multifilament tows containing high-performance Sylramic (Dow Corning) SiC fiber that is woven into two-dimensional five-harness satin fabric with 20 ends per inch in the 0 degree and 90 degree directions. In some cases, fabric pieces containing woven Sylramic fiber tows are thermally treated at NASA to form Sylramic-iBN fibers that contain a very thin in-situ-grown boron nitride layer on their surfaces. The final SiC/SiC panels and components are fabricated at the CMC vendor by compressing the fabric pieces in tools and then depositing a thin BN interphase coating on the fibers by chemical vapor deposition. The last step at the vendor is to infiltrate the BN-coated fiber architecture with SiC and silicon matrix constituents to form a dense product. Because the as-produced Sylramic fiber tows are sized with a thin polymer coating to facilitate handling and weaving, the individual fibers within the tows and fabric are in close contact with each other. This contact is further increased during fabric compression. One important recent finding is that increasing Sylramic fiber tow width in a fabric increases the UTS of the final SiC/SiC CMC. This effect is presumably related to minimizing fiber/fiber contact, which can be detrimental to CMC strength because of the boron-rich chemistry and roughness of the Sylramic fiber surface. Tows can be spread by mechanically agitating the Sylramic fabric prior to CMC fabrication or by simply thermally treating the Sylramic fabric as in the formation of the Sylramic-iBN fibers. However, CMC's with the treated Sylramic-iBN fabric are even stronger than CMC's with mechanically spread Sylramic tows. The extra strength capability is presumably related to the in situ BN on the fiber surface, which adds compliance to the fiber surfaces and is more resistant to oxygen impurities introduced during the chemical vapor deposition BN process. As shown, another important finding is that the use of fabric with tows having less than the standard of 20 ends per inch provides advantages in terms of reduced ply height and increased ply and CMC strength. The reduced ply height provides more control of part thickness by allowing more plies for a given thickness and by reducing interlaminar residual stresses between plies. The increased ply strength is presumably related to a reduced number of interlaced 90 tows, which, in turn, reduces the crimp angle on the high-modulus fibers in the 0 degree tows. Also, as shown, although fabric with fewer ends per inch reduced the maximum fiber fraction in an eight-ply CMC panel; CMC UTS actually increased because of increased ply strength. Thus, using fabric with fewer ends per inch has several advantages, including providing a significantly higher strength per fiber fraction in the CMC. Consequently, ongoing UEET efforts will attempt to use architectural approaches for components that minimize fiber-fiber contacts and fiber bending within the final composite microstructure.

33 CFR 164.72 - Navigational-safety equipment, charts or maps, and publications required on towing vessels.

Code of Federal Regulations, 2014 CFR

2014-07-01

... magnetic steering compass readable from the vessel's main steering station, if the vessel engages in towing... engages in towing on navigable waters of the U.S., including Western Rivers, the radar must meet— (A) The... than 300 tons gross tonnage that engages in towing seaward of navigable waters of the U.S. or more than...

33 CFR 164.72 - Navigational-safety equipment, charts or maps, and publications required on towing vessels.

Code of Federal Regulations, 2013 CFR

2013-07-01

... magnetic steering compass readable from the vessel's main steering station, if the vessel engages in towing... engages in towing on navigable waters of the U.S., including Western Rivers, the radar must meet— (A) The... than 300 tons gross tonnage that engages in towing seaward of navigable waters of the U.S. or more than...

Standardized UXO Technology Demonstration Site Blind Grid Scoring Record No. 806 (U.S. Geological Survey, TMGS Magnetometer/Towed Array)

DTIC Science & Technology

2007-05-01

BOX 25046, FEDERAL CENTER, M.S. 964 DENVER, CO 80225-0046 TECHNOLOGY TYPE/PLATFORM: TMGS MAGNETOMETER/TOWED ARRAY PREPARED BY: U.S. ARMY...GEOLOGICAL SURVEY, TMGS MAGNETOMETER/TOWED ARRAY) 8-CO-160-UXO-021 Karwatka, Michael... TMGS Magnetometer/Towed Array, MEC Unclassified Unclassified Unclassified SAR (Page ii Blank) i ACKNOWLEDGMENTS

46 CFR 2.01-50 - Persons other than crew on towing, oyster, or fishing steam vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Persons other than crew on towing, oyster, or fishing... than crew on towing, oyster, or fishing steam vessels. (a) A steam vessel engaged in towing, oyster dredging and planting, and fishing may be permitted to carry persons in addition to its crew. (b) The...

46 CFR 2.01-50 - Persons other than crew on towing, oyster, or fishing steam vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Persons other than crew on towing, oyster, or fishing... than crew on towing, oyster, or fishing steam vessels. (a) A steam vessel engaged in towing, oyster dredging and planting, and fishing may be permitted to carry persons in addition to its crew. (b) The...

49 CFR 393.42 - Brakes required on all wheels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... subject to this part is not required to be equipped with brakes if the axle weight of the towed vehicle does not exceed 40 percent of the sum of the axle weights of the towing vehicle. (4) Any full trailer... of the towed vehicle does not exceed 40 percent of the sum of the axle weights of the towing vehicle...

46 CFR 2.01-50 - Persons other than crew on towing, oyster, or fishing steam vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Persons other than crew on towing, oyster, or fishing steam vessels. 2.01-50 Section 2.01-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES... than crew on towing, oyster, or fishing steam vessels. (a) A steam vessel engaged in towing, oyster...

Full waveform inversion of combined towed streamer and limited OBS seismic data: a theoretical study

NASA Astrophysics Data System (ADS)

Yang, Huachen; Zhang, Jianzhong

2018-06-01

In marine seismic oil exploration, full waveform inversion (FWI) of towed-streamer data is used to reconstruct velocity models. However, the FWI of towed-streamer data easily converges to a local minimum solution due to the lack of low-frequency content. In this paper, we propose a new FWI technique using towed-streamer data, its integrated data sets and limited OBS data. Both integrated towed-streamer seismic data and OBS data have low-frequency components. Therefore, at early iterations in the new FWI technique, the OBS data combined with the integrated towed-streamer data sets reconstruct an appropriate background model. And the towed-streamer seismic data play a major role in later iterations to improve the resolution of the model. The new FWI technique is tested on numerical examples. The results show that when starting models are not accurate enough, the models inverted using the new FWI technique are superior to those inverted using conventional FWI.

Impact of Advanced Pharmacy Practice Experience Placement Changes in Colleges and Schools of Pharmacy

PubMed Central

Staton, April G.; McCullough, Elizabeth S.; Jain, Rahul; Miller, Mindi S.; Lynn Stevenson, T.; Fetterman, James W.; Lynn Parham, R.; Sheffield, Melody C.; Unterwagner, Whitney L.; McDuffie, Charles H.

2012-01-01

Objective. To document the annual number of advanced pharmacy practice experience (APPE) placement changes for students across 5 colleges and schools of pharmacy, identify and compare initiating reasons, and estimate the associated administrative workload. Methods. Data collection occurred from finalization of the 2008-2009 APPE assignments throughout the last date of the APPE schedule. Internet-based customized tracking forms were used to categorize the initiating reason for the placement change and the administrative time required per change (0 to 120 minutes). Results. APPE placement changes per institution varied from 14% to 53% of total assignments. Reasons for changes were: administrator initiated (20%), student initiated (23%), and site/preceptor initiated (57%) Total administrative time required per change varied across institutions from 3,130 to 22,750 minutes, while the average time per reassignment was 42.5 minutes. Conclusion. APPE placements are subject to high instability. Significant differences exist between public and private colleges and schools of pharmacy as to the number and type of APPE reassignments made and associated workload estimates. PMID:22544966

Demonstration of Advanced EMI Models for Live-Site UXO Discrimination at Waikoloa, Hawaii

DTIC Science & Technology

2015-12-01

magnetic source models PNN Probabilistic Neural Network SERDP Strategic Environmental Research and Development Program SLO San Luis Obispo...SNR Signal to noise ratio SVM Support vector machine TD Time Domain TEMTADS Time Domain Electromagnetic Towed Array Detection System TOI... intrusive procedure, which was used by Parsons at WMA, failed to document accurately all intrusive results, or failed to detect and clear all UXO like

Creep of Hi-Nicalon S Fiber Tows at Elevated Temperature in Air and in Steam

DTIC Science & Technology

2013-03-01

materials”[28]. Materials have always been a limiting factor in the advancements of technology. The ever increasing demand for aerospace vehicles that are...matrix composites are designed to have load-carrying capacity at high temperatures in extreme environments. Ceramic matrix composites are prime...engines, gas turbines for electrical power/steam cogeneration , as well as nuclear power plant components. It is recognized that the structural

An Acoustic Source Reactive to Tow Cable Strum

DTIC Science & Technology

2012-09-21

sound wave radiates from the head mass. Dkt . No. 101720 Application No. ?? REPLACEMENT SHEET? /3 DRAFT 1 CABLE CURVATURE INDUCING LONGITUDINAL...MOTION IDEALIZED TOW CABLE (NO TRANSVERSE VIBRATION) REALISTIC TOW CABLE (INCLUDES TRANSVERSE VIBRATION) DIRECTION OF TOW FIG. 1 (PRIOR ART) Dkt . No...DISPLACEMENT DISPLACEMENT LONGITUDINAL (PRIOR ART) DISPLACEMENT LONGITUDINAL Dkt . No. 101720 Application No. ?? REPLACEMENT SHEET? /3 DRAFT 10 A B B A

Eclipse project QF-106 and C-141A climbs out under tow on first tethered flight December 20, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

TOW LAUNCH DEMONSTRATION - The Kelly Space & Technology (KST)/USAF/NASA Eclipse project's modified QF-106 climbs out under tow by a USAF C-141A on the project's first tethered flight on December 20, 1997. The successful 18-minute-long flight reached an altitude of 10,000 feet. NASA's Dryden Flight Research Center, Edwards, California, hosted the project, providing engineering and facility support as well as the project pilot. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

2014 Advanced Placement Exam Participation and Performance for Students in Montgomery County Public Schools and Public School Students in the State of Maryland and the Nation. Memorandum

ERIC Educational Resources Information Center

Sanderson, Geoffrey T.

2014-01-01

The continuing emphasis by Montgomery County (Maryland) Public Schools (MCPS) on rigorous course taking resulted in MCPS students taking a record-setting 33,662 Advanced Placement (AP) exams in 2014. Additionally, the percentage of AP exams taken by MCPS students who attained scores of 3 or higher (73.9 percent) was 13.0 and 16.7 percentage points…

More Home Schoolers Taking Advanced Placement Tests: Students Seek Outside Validation of Work and Leg Up on College-Admissions Process

ERIC Educational Resources Information Center

Zehr, Mary Ann

2006-01-01

When Susan Richman called the College Board in 1992 to ask if her son Jesse could take Advanced Placement tests as a home schooler, a staff member responded that no one had ever asked him that question, but then assured her that home schoolers were welcome to take the tests. Ms. Richman went on to coach Jesse for so many AP exams that he started…

AdVance male sling

PubMed Central

Chung, Amanda S. J.; Suarez, Oscar A.

2017-01-01

The AdVance sling (American Medical Systems, Minnetonka, MN, United States of America) is a synthetic transobturator sling, which is a safe and effective minimally invasive treatment for mild to moderate stress urinary incontinence (SUI) in male patients. This article provides a step-by-step description of our technique for placement of the AdVance male sling, including details and nuances gained from surgical experience, advice for avoidance of complications and discussion on management of complications and sling failures. Patient selection is very important, including exclusion and preoperative treatment of urethral stenosis and bladder dysfunction. Previous pelvic radiation is a poor prognostic factor. In brief, the steps of sling placement are: (I) mobilization of the corpus spongiosum (CS); (II) marking and mobilization of the central tendon; (III) passage of the helical trocar needles exiting at the apex of the angle between the CS and inferior pubic ramus; (IV) fixation of the broad part of the sling body to the CS at the previous mark; (V) cystoscopy during sling tensioning; (VI) placement of a Foley urethral catheter; (VII) Subcutaneous tunnelling of the sling arms back toward the midline; (VIII) wound closure. The most common early postoperative complication is urinary retention but long-term retention is extremely rare. Management of sling failures include placement of an artificial urinary sphincter, repeat AdVance sling, urethral bulking agent or ProACT device. PMID:28904900

SEADYN Analysis of a Tow Line for a High Altitude Towed Glider

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.

1996-01-01

The concept of using a system, consisting of a tow aircraft, glider and tow line, which would enable subsonic flight at altitudes above 24 km (78 kft) has previously been investigated. The preliminary results from these studies seem encouraging. Under certain conditions these studies indicate the concept is feasible. However, the previous studies did not accurately take into account the forces acting on the tow line. Therefore in order to investigate the concept further a more detailed analysis was needed. The code that was selected was the SEADYN cable dynamics computer program which was developed at the Naval Facilities Engineering Service Center. The program is a finite element based structural analysis code that was developed over a period of 10 years. The results have been validated by the Navy in both laboratory and at actual sea conditions. This code was used to simulate arbitrarily-configured cable structures subjected to excitations encountered in real-world operations. The Navy's interest was mainly for modeling underwater tow lines, however the code is also usable for tow lines in air when the change in fluid properties is taken into account. For underwater applications the fluid properties are basically constant over the length of the tow line. For the tow aircraft/glider application the change in fluid properties is considerable along the length of the tow line. Therefore the code had to be modified in order to take into account the variation in atmospheric properties that would be encountered in this application. This modification consisted of adding a variable density to the fluid based on the altitude of the node being calculated. This change in the way the code handled the fluid density had no effect on the method of calculation or any other factor related to the codes validation.

Closeup of QF-106 release hook for Eclipse program

NASA Technical Reports Server (NTRS)

1997-01-01

View of the release hook on the QF-106 that allowed the pilot to release the tow rope extending from the C-141A tow plane in the Eclipse project. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Eclipse program C-141A aircraft

NASA Technical Reports Server (NTRS)

1997-01-01

This photograph shows the Air Force C-141A that was used in the Eclipse project as a tow vehicle. The project used a QF-106 interceptor aircraft to simulate a future orbiter, which would be towed to a high altitude and released to fire its own engines and carry a payload into space. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Advanced composite fuselage technology

NASA Technical Reports Server (NTRS)

Ilcewicz, Larry B.; Smith, Peter J.; Horton, Ray E.

1993-01-01

Boeing's ATCAS program has completed its third year and continues to progress towards a goal to demonstrate composite fuselage technology with cost and weight advantages over aluminum. Work on this program is performed by an integrated team that includes several groups within The Boeing Company, industrial and university subcontractors, and technical support from NASA. During the course of the program, the ATCAS team has continued to perform a critical review of composite developments by recognizing advances in metal fuselage technology. Despite recent material, structural design, and manufacturing advancements for metals, polymeric matrix composite designs studied in ATCAS still project significant cost and weight advantages for future applications. A critical path to demonstrating technology readiness for composite transport fuselage structures was created to summarize ATCAS tasks for Phases A, B, and C. This includes a global schedule and list of technical issues which will be addressed throughout the course of studies. Work performed in ATCAS since the last ACT conference is also summarized. Most activities relate to crown quadrant manufacturing scaleup and performance verification. The former was highlighted by fabricating a curved, 7 ft. by 10 ft. panel, with cocured hat-stiffeners and cobonded J-frames. In building to this scale, process developments were achieved for tow-placed skins, drape formed stiffeners, braided/RTM frames, and panel cure tooling. Over 700 tests and supporting analyses have been performed for crown material and design evaluation, including structural tests that demonstrated limit load requirements for severed stiffener/skin failsafe damage conditions. Analysis of tests for tow-placed hybrid laminates with large damage indicates a tensile fracture toughness that is higher than that observed for advanced aluminum alloys. Additional recent ATCAS achievements include crown supporting technology, keel quadrant design evaluation, and sandwich process development.

14 CFR 25.509 - Towing loads.

Code of Federal Regulations, 2012 CFR

2012-01-01

... wheel to which the load is applied. Enough airplane inertia to achieve equilibrium must be applied. (ii) The loads must be reacted by airplane inertia. (d) The prescribed towing loads are as follows: Tow...

14 CFR 25.509 - Towing loads.

Code of Federal Regulations, 2013 CFR

2013-01-01

... wheel to which the load is applied. Enough airplane inertia to achieve equilibrium must be applied. (ii) The loads must be reacted by airplane inertia. (d) The prescribed towing loads are as follows: Tow...

14 CFR 25.509 - Towing loads.

Code of Federal Regulations, 2014 CFR

2014-01-01

... wheel to which the load is applied. Enough airplane inertia to achieve equilibrium must be applied. (ii) The loads must be reacted by airplane inertia. (d) The prescribed towing loads are as follows: Tow...

Investigations and Tests in the Towing Basin at Guidonia

NASA Technical Reports Server (NTRS)

Cremona, C

1939-01-01

The experimental methods at the Guidonia towing basin are discussed including specifications. Some of the components examined are the bridge towing carriage, side towing carriage, catapult installation, and dynamometer systems. Tests were performed on hulls and floats, as well as motor boats and torpedo shaped bodies. Theoretical investigations were also performed to determine pressure distributions on geometrically simple bodies, propagation of small wave motions, and planing and submerged surfaces.

14 CFR 25.509 - Towing loads.

Code of Federal Regulations, 2010 CFR

2010-01-01

... static positions; and (3) With W T as the design ramp weight, the towing load, F TOW, is— (i) 0.3 W T for W T less than 30,000 pounds; (ii) (6W T+450,000)/7 for W T between 30,000 and 100,000 pounds; and (iii) 0.15 W T for W T over 100,000 pounds. (b) For towing points not on the landing gear but near the...

14 CFR 25.509 - Towing loads.

Code of Federal Regulations, 2011 CFR

2011-01-01

... static positions; and (3) With W T as the design ramp weight, the towing load, F TOW, is— (i) 0.3 W T for W T less than 30,000 pounds; (ii) (6W T+450,000)/7 for W T between 30,000 and 100,000 pounds; and (iii) 0.15 W T for W T over 100,000 pounds. (b) For towing points not on the landing gear but near the...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wachsman, A.M., E-mail: ariw@fusemail.com; Hoffer, E.K.; Forauer, A.R.

A case of tension pneumothorax developed after placement of a tunneled pleural catheter for treatment of malignant pleural effusion in a patient with advanced lung cancer. The catheter placement was carried out by an experienced operator under direct ultrasound guidance, and the patient showed immediate symptomatic improvement with acute decompensation occurring several hours later. Possible mechanisms for this serious complication of tunneled pleural catheter placement are described, and potential strategies to avoid or prevent it in future are discussed.

Examining School Counselor Influence on the Placement of Ninth-Grade Students into Mathematics Courses: An Analysis of the High School Longitudinal Study of 2009

ERIC Educational Resources Information Center

Bradley-Lambright, Portia Elizabeth

2016-01-01

The purpose of this quantitative study was to understand the placement of ninth-grade students within advanced mathematics courses. High school counselors are often criticized for being an ineffective resource in the placement of students of color and low-income students into such classes; even though their professional mandates state that they…

Winding a Long Coil with a Pre-Programmed Turns Density Variation

DTIC Science & Technology

1975-05-27

turns den- sity is to follow. A machine having this capability is needed to provide a towed ELF loop antenna with the smoothly tapered sensitivity...Introduction A submarine towed ELF loop antenna vibrates longitudinally and trans- versely during towing. The vibration is driven by the fluctuating surface...in attaining the smoothly varying turns density required for the signal winding of a towed ELF loop antenna . Acknowledgments Thanks are due to John

36 CFR 3.12 - May I use a vessel to tow a person for water skiing or other similar activities?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.12 May I use a vessel to tow a person for water skiing or other similar activities? (a) The towing of a person... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false May I use a vessel to tow a...

36 CFR 3.12 - May I use a vessel to tow a person for water skiing or other similar activities?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.12 May I use a vessel to tow a person for water skiing or other similar activities? (a) The towing of a person... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false May I use a vessel to tow a...

Engineered Polymer Composites Through Electrospun Nanofiber Coating of Fiber Tows

NASA Technical Reports Server (NTRS)

Kohlman, Lee W.

2013-01-01

Toughening and other property enhancements of composite materials are typically implemented by-modifying the bulk properties of the constituents, either the fiber or matrix materials. This often leads to difficulties in processing and higher material costs. Many composites consist of tows or yarns (thousands of individual fibers) that are either filament wound or processed into a fabric by weaving or braiding. The matrix material can be added to the tow or fabric before final processing, resulting in a prepreg material, or infused into the fiber material during final processing by a variety of methods. By using a direct electrospun deposition method to apply thermoplastic nanofiber to the surface of the tows, the tow-tow interface in the resulting composite can be modified while using otherwise conventional materials and handling processes. Other materials of interest could also be incorporated into the electrospun precursor.

Advanced Unmanned Search System (AUSS) Performance Analysis

DTIC Science & Technology

1979-07-15

interference (from thrusters , flow noise , etc.) with sonar data; (4) Sonar range scales can be adjusted, on scene, for viewing the same contacts with...intact. The H-bomb search was performed at 2000 feet, the sub- marine search at 8400 feet. An additional submarine search was selected at 20,000 feet to...Sonar Targets," by Stephen Miller, Marine Physical Laboratory, Scripps Institution of Oceanography, January 1977. 10 Table 2. Baseline towed system

Eclipse program C-141A aircraft

NASA Technical Reports Server (NTRS)

1997-01-01

This photograph shows the Air Force C-141A that was used in the Eclipse project as a tow vehicle. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wind loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

In-Situ NDE Characterization of Kevlar and Carbon Composite Micromechanics for Improved COPV Health Monitoring

NASA Technical Reports Server (NTRS)

Waller, Jess M.; Saulsberry, Regor L.

2009-01-01

This project is a subtask of a multi-center project to advance the state-of-the-art by developing NDE techniques that are capable of evaluating stress rupture (SR) degradation in Kevlar/epoxy (K/Ep) composite overwrapped pressure vessels (COPVs), and damage progression in carbon/epoxy (C/Ep) COPVs. In this subtask, acoustic emission (AE) data acquired during intermittent load hold tensile testing of K/Ep and C/Ep composite tow materials-of-construction used in COPV fabrication were analyzed to monitor progressive damage during the approach to tensile failure. Insight into the progressive damage of composite tow was gained by monitoring AE event rate, energy, source location, and frequency. Source location based on arrival time data was used to discern between significant AE attributable to microstructural damage and spurious AE attributable to background and grip noise. One of the significant findings was the observation of increasing violation of the Kaiser effect (Felicity ratio < 1.0) with damage accumulation.

Non-consent towing cost study in Utah.

DOT National Transportation Integrated Search

2015-01-01

This study was conducted on behalf of the UDOT Motor Carrier Division at the request of the towing industry in : Utah to evaluate the maximum allowable rates for Non-Consent Towing. The objectives were to: 1-Evaluate : the Current Maximum...

Comparison of Temporal Parameters of Swimming Rescue Elements When Performed Using Dolphin and Flutter Kick with Fins - Didactical Approach

PubMed Central

Rejman, Marek; Wiesner, Wojciech; Silakiewicz, Piotr; Klarowicz, Andrzej; Abraldes, J. Arturo

2012-01-01

The aim of this study was an analysis of the time required to swim to a victim and tow them back to shore, while perfoming the flutter-kick and the dolphin-kick using fins. It has been hypothesized that using fins while using the dolphin-kick when swimming leads to reduced rescue time. Sixteen lifeguards took part in the study. The main tasks performed by them, were to approach and tow (double armpit) a dummy a distance of 50m while applying either the flutter-kick, or the dolphin-kick with fins. The analysis of the temporal parameters of both techniques of kicking demonstrates that, during the approach to the victim, neither the dolphin (tmean = 32.9s) or the flutter kick (tmean = 33.0s) were significantly faster than the other. However, when used for towing a victim the flutter kick (tmean = 47.1s) was significantly faster when compared to the dolphin-kick (tmean = 52.8s). An assessment of the level of technical skills in competitive swimming, and in approaching and towing the victim, were also conducted. Towing time was significantly correlated with the parameter that linked the temporal and technical dimensions of towing and swimming (difference between flutter kick towing time and dolphin-kick towing time, 100m medley time and the four swimming strokes evaluation). No similar interdependency has been discovered in flutter kick towing time. These findings suggest that the dolphin-kick is a more difficult skill to perform when towing the victim than the flutter-kick. Since the hypothesis stated was not confirmed, postulates were formulated on how to improve dolphin-kick technique with fins, in order to reduce swimming rescue time. Key points The source of reduction of swimming rescue time was researched. Time required to approach and to tow the victim while doing the flutter kick and the dolphin-kick with fins was analyzed. The propulsion generated by dolphin-kick did not make the approach and tow faster than the flutter kick. More difficult skill to realize of dolphin-kick than the flutter-kick was postulated. The criteria for how improve dolphin kick technique with fins were formulated. PMID:24150079

Spatial-Gain Improvement Resulting from Left/Right Discriminating Elements of an Underwater Towed Array

DTIC Science & Technology

1981-09-15

DISCRIMINATING ELEMENTS OF AN UNDERWATER TOWED ARRAY rsil RONALD A. WAGSTAFF and PIETRO MANASCA D TIC": L• ’" .... 4"•’.,, 15 SEPTEMBER 1981...IMPROVEMENT RESULTING FROM LEFT/RIGHT DISCRIMINATING ELEMENTS OF AN UNDERWATER TOWED ARRAY by Ronald A. Wagstaff and Pietro Zanasca 15 September 1981 F...RESULTING FROM LEFT/RIGHT DISCRIMINATING ELEMENTS OF AN UNDERWATER TOWED ARRAY by Ronald A. Wagstaff and Pietro Zanasca ABSTRACT The improvement in

System Applies Polymer Powder To Filament Tow

NASA Technical Reports Server (NTRS)

Baucom, Robert M.; Snoha, John J.; Marchello, Joseph M.

1993-01-01

Polymer powder applied uniformly and in continuous manner. Powder-coating system applies dry polymer powder to continuous fiber tow. Unique filament-spreading technique, combined with precise control of tension on fibers in system, ensures uniform application of polymer powder to web of spread filaments. Fiber tows impregnated with dry polymer powders ("towpregs") produced for preform-weaving and composite-material-molding applications. System and process valuable to prepreg industry, for production of flexible filament-windable tows and high-temperature polymer prepregs.

Improvement of quality of life and survival using self-expandable metal stent placement for severe malignant stenosis of the gastric body: a case report.

PubMed

Kumagai, Hozumi; Nio, Kenta; Shirakawa, Tsuyoshi; Uchino, Keita; Kusaba, Hitoshi; Isobe, Taichi; Komoda, Masato; Tamura, Shingo; Maeyama, Ryo; Nagai, Eishi; Akashi, Koichi; Baba, Eishi

2012-09-19

Advanced gastric carcinoma often decreases quality of life because of upper gastrointestinal tract stenosis. Self-expandable metal stents have been thought to be an effective, minimally invasive treatment for stenosis. However, the effectiveness of self-expandable metal stent placement for carcinomatous stenosis of the gastric body and antrum has not been clarified, and there have been few reports of such cases. A 74-year-old Japanese woman developed stenosis of the gastric body and antrum caused by advanced gastric cancer during first-line chemotherapy. She developed weight loss and poor nutrition due to inadequate intake. Self-expandable metal stent placement for stenosis of the gastric body and antrum ameliorated her symptoms rapidly and improved her general condition and quality of life. Eight days after self-expandable metal stent placement, second-line chemotherapy could be administered safely. Oral intake and nutritional status were maintained for 117 days after self-expandable metal stent placement, and she died of gastric cancer 176 days after self-expandable metal stent placement and initiation of second-line chemotherapy. Self-expandable metal stent placement for carcinomatous stenosis in the gastric body and antrum could be an effective therapeutic strategy for patients with inadequate oral uptake. It may provide rapid improvement of the patient's general condition and oral intake with minimal complications, comparatively long-term symptom relief, and a survival benefit by allowing second-line chemotherapy.

Esophageal stent fixation with endoscopic suturing device improves clinical outcomes and reduces complications in patients with locally advanced esophageal cancer prior to neoadjuvant therapy: a large multicenter experience.

PubMed

Yang, Juliana; Siddiqui, Ali A; Kowalski, Thomas E; Loren, David E; Khalid, Ammara; Soomro, Ayesha; Mazhar, Syed M; Rosé, Julian; Isby, Laura; Kahaleh, Michel; Kalra, Ankush; Sarkisian, Alex M; Kumta, Nikhil A; Nieto, Jose; Sharaiha, Reem Z

2017-03-01

Endoscopic placement of fully covered self-expanding metal stents (FCSEMS) to treat malignant dysphagia in patients with esophageal cancer significantly improves dysphagia; however, these stents have a high migration rate. To determine whether FCSEMS fixation using an endoscopic suturing device treated malignant dysphagia and prevented stent migration in patients with locally advanced esophageal cancer receiving neoadjuvant therapy when compared to patients with FCSEMS placement alone. A review of patients with locally advanced esophageal cancer who underwent FCSEMS placement at 3 centers was performed. Patients were divided into two groups: Group A (n = 26) was composed of patients who underwent FCSEMS placement with suture placement, and Group B (n = 67) was composed of patients with FCSEMS placement alone. There were no significant differences between Groups A and B in demographics, and tumor characteristics. The technical success rate for stent placement was 100 %. There was no difference between Groups A and B in the median stent diameter and stent lengths. Mean dysphagia score obtained at 1 week after stent placement had improved significantly from baseline (2.4 and 1, respectively, p < 0.001). Patients had a median follow-up of 4 months. Immediate adverse events were mild chest discomfort in 4 patients in Group A and 2 patients in Group B (p = 0.05), and significant acid reflux in 3 patient in Group A compared to 2 patients in Group B (p = 0.1). The stent migration rate was significantly lower in Group A compared to compared to Group B (7.7 vs 26.9 %, respectively, p = 0.004). There was a delayed perforation in 1 patient and 1 death due to aspiration pneumonia in Group B. Fixation of esophageal FCSEMSs by using an endoscopic suturing device in patients receiving neoadjuvant therapy was shown to be feasible, safe, and relatively effective at preventing stent migration compared to those who had stent placed alone.

46 CFR 27.101 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS TOWING VESSELS General Provisions for Fire-Protection... satisfies the National Fire Protection Association (NFPA) Standard 2001 (incorporated by reference in § 27... or coastal service. Towing vessel in ocean or coastal service means a towing vessel that operates...

46 CFR 27.101 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS TOWING VESSELS General Provisions for Fire-Protection... the Commandant; (2) A manually-operated clean-agent system that satisfies the National Fire Protection... or coastal service. Towing vessel in ocean or coastal service means a towing vessel that operates...

46 CFR 27.101 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS TOWING VESSELS General Provisions for Fire-Protection... satisfies the National Fire Protection Association (NFPA) Standard 2001 (incorporated by reference in § 27... or coastal service. Towing vessel in ocean or coastal service means a towing vessel that operates...

The link between middle school mathematics course placement and achievement.

PubMed

Domina, Thurston

2014-01-01

The proportion of eighth graders in United States public schools enrolled in algebra or a more advanced mathematics course doubled between 1990 and 2011. This article uses Early Childhood Longitudinal Study's Kindergarten Cohort data to consider the selection process into advanced middle school mathematics courses and estimate the effects of advanced courses on students' mathematics achievement (n = 6,425; mean age at eighth grade = 13.7). Eighth-grade algebra and geometry course placements are academically selective, but considerable between-school variation exists in students' odds of taking these advanced courses. While analyses indicate that advanced middle school mathematics courses boost student achievement, these effects are most pronounced in content areas closely related to class content and may be contingent on student academic readiness. © 2014 The Author. Child Development © 2014 Society for Research in Child Development, Inc.

Eclipse project closeup of QF-106 under tow on takeoff on first flight December 20, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

OFF THE GROUND - The Kelly Space & Technology (KST)/USAF/NASA Eclipse project's modified QF-106 lifts off under tow on the project's first tethered flight on December 20, 1997. The successful 18-minute-long flight reached an altitude of 10,000 feet. NASA's Dryden Flight Research Center, Edwards, California, hosted the project, providing engineering and facility support as well as the project pilot. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Eclipse project closeup of QF-106 under tow on first tethered flight December 20, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

The Kelly Space and Technology (KST)/USAF/NASA Eclipse project's modified QF-106 is shown under tow on the project's first tethered flight on December 20, 1997. The successful 18-minute-long flight reached an altitude of 10,000 feet. NASA's Dryden Flight Research Center, Edwards, California, is hosting the project, providing engineering and facility support as well as the project pilot, Mark Stucky. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Simulation of Complex Cracking in Plain Weave C/SiC Composite under Biaxial Loading

NASA Technical Reports Server (NTRS)

Cheng, Ron-Bin; Hsu, Su-Yuen

2012-01-01

Finite element analysis is performed on a mesh, based on computed geometry of a plain weave C/SiC composite with assumed internal stacking, to reveal the pattern of internal damage due to biaxial normal cyclic loading. The simulation encompasses intertow matrix cracking, matrix cracking inside the tows, and separation at the tow-intertow matrix and tow-tow interfaces. All these dissipative behaviors are represented by traction-separation cohesive laws. Not aimed at quantitatively predicting the overall stress-strain relation, the simulation, however, does not take the actual process of fiber debonding into account. The fiber tows are represented by a simple rule-of-mixture model where the reinforcing phase is a hypothetical one-dimensional material. Numerical results indicate that for the plain weave C/SiC composite, 1) matrix-crack initiation sites are primarily determined by large intertow matrix voids and interlayer tow-tow contacts, 2) the pattern of internal damage strongly depends on the loading path and initial stress, 3) compressive loading inflicts virtually no damage evolution. KEY WORDS: ceramic matrix composite, plain weave, cohesive model, brittle failure, smeared crack model, progressive damage, meso-mechanical analysis, finite element.

Evaluation of the Viking-Cives tow plow.

DOT National Transportation Integrated Search

2009-05-01

In early February, 2009, the Maine Department of Transportation (MaineDOT) entered into an agreement : with Viking-Cives USA to evaluate the Viking-Cives Tow Plow. MaineDOT agreed to evaluate the Tow : Plow for the remainder of the 2008-2009 winter s...

77 FR 49002 - Towing Safety Advisory Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-15

... concurrent meetings of the four subcommittees, ``Recommendations for the Prevention of Towing Vessel Crewmember Falls Overboard'', ``Review and recommendations for the revision of NVIC 1-95, Voluntary Training Standards for Entry-Level Personnel on Towing Industry Vessels'', ``Recommendations for the Enhancement of...

Method and apparatus for deregistering multi-filament tow and product thereof

DOEpatents

Lukhard, Craig R.; Potter, Jerry F.; Todd, Maurice C.

1995-01-01

A method and apparatus for deregistering drawn crimped nylon multifilament tow includes the steps of stretching the tow under constant controlled tension at a temperature below the glass transition temperature of the nylon. The apparatus includes means for sensing the tension of the tow between the feed and draw sections of a stretching device and producing a signal representative of the tension sensed and a controller for changing the speed of the draw section actuated by said signal.

Design, Manufacture and Test of Cryotank Components

NASA Technical Reports Server (NTRS)

McCarville, Douglas A.; Guzman, Juan C.; Dillon. Alexandra K.; Jackson, Justin R.; Birkland, Jordan O.

2017-01-01

On the composite cryotank technology development (CCTD) project, the Boeing Company built two cryotanks as a means of advancing technology and manufacturing readiness levels (TRL and MRL) and lowering the risk of fabricating full-scale fuel containment vessels.1 CCTD focused on upper stage extended duration applications where long term storage of propellants is required. The project involved the design, analysis, fabrication, and test of manufacturing demonstration units (MDU), a 2.4 m (precursor) and a 5.5 m composite cryotank. Key design features included one-piece wall construction to minimize overall weight (eliminating the need for a bellyband joint), 3-dimensionally (3D) reinforced y-joint material to alleviate stress concentrations at the tank to skirt interface and a purge-able ?uted core skirt to carry high axial launch loads. The tanks were made with OoA curing pre-impregnated (prepreg) carbon/epoxy (C/E) slit-tape tow (STT) that contained thin micro-crack resistant plies in the tank wall center to impede permeation. The tanks were fabricated at Boeing's Seattle-based Advanced Development Center (ADC) using RAFP and multipiece break-down tooling. The tooling was designed and built by Janicki Industries (JI) at Sedro Woolley, Washington. Tank assemblage consisted of co-bonded dome covers, one-piece ?uted core skirts and mechanical fastened cover/sump. Ultrasonic inspection was performed after every cure or bond and a structural health monitoring system (SHMS) was installed to identify potential impact damage events (in-process and/or during transportation). The tanks were low temperature tested at NASA's George C. Marshall Space Flight Center (MSFC) in Huntsville, Alabama. The testing, which consisted of a sequence of ?ll/drain pressure and thermal cycles using LH2, was successfully concluded in 2012 on the 2.4 m tank and in 2014 on the 5.5 m tank. Structural, thermal, and permeation performance data was obtained. 2 Critical design features and manufacturing advancements, which helped to validate 25% weight and 30% cost reduction projections, were matured. These advancements will help to guide future composite tank integration activities on next generation long duration aircraft and space launch vehicles. Because CCTD addressed innovative design features, heavy lift size scale-up, multipiece captured tooling, new generation automated material placement (AMP) equipment and OoA materials, this chapter should be of interest to educators, students and manufacturers of composite hardware and ?ight vehicles.

75 FR 20856 - Towing Safety Advisory Committee; Vacancies

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-21

... the Coast Guard on matters relating to shallow-draft inland and coastal waterway navigation and towing... advises the Secretary of Homeland Security on matters relating to shallow-draft inland and coastal... with shallow-draft inland and coastal waterway navigation and towing safety. Registered lobbyists are...

Evaluating the use of tow plows in Michigan.

DOT National Transportation Integrated Search

2016-09-30

The main objective of this project is to identify the cost-benefit of Tow Plow usage on different : routes in order to determine where Tow Plows can be included in the snow maintenance fleet in a : safe and economical manner. : During this study, sta...

Evaluating the use of tow plows in Michigan.

DOT National Transportation Integrated Search

2016-09-30

The main objective of this project is to identify the cost-benefit of Tow Plow usage on different routes in order to determine where Tow Plows can be included in the snow maintenance fleet in a safe and economical manner. During this study, state-of-...

78 FR 60890 - Towing Safety Advisory Committee; Vacancies

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-02

... representing the barge and towing industry reflecting a regional geographical balance; [cir] One member... general public. The Coast Guard is currently considering applications for six positions that will become... regional geographic balance; One member representing holders of active licensed Masters or Pilots of towing...

15. VIEW NORTHNORTHEAST OF TOW TANK No. 2, DEWATERED. ENCLOSED ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. VIEW NORTH-NORTHEAST OF TOW TANK No. 2, DEWATERED. ENCLOSED AREAS AT BACK OF TUNNEL IS A HOUSING FOR CONDUCTING PERFORMANCE TESTING ON AIRCRAFT MODELS IN A VORTEX. - NASA Langley Research Center, Seaplane Towing Channel, 108 Andrews Street, Hampton, Hampton, VA

Eclipse program F-106 aircraft in flight, front view

NASA Technical Reports Server (NTRS)

1997-01-01

Shot of the QF-106 aircraft in flight with the landing gear deployed. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

[Eleven Patients with Gastric Cancer Who Received Chemotherapy after Stent Placement for Gastric Outlet Obstruction].

PubMed

Endo, Shunji; Nakagawa, Tomo; Konishi, Ken; Ikenaga, Masakazu; Ohta, Katsuya; Nakashima, Shinsuke; Matsumoto, Kenichi; Nishikawa, Kazuhiro; Ohmori, Takeshi; Yamada, Terumasa

2017-01-01

Endoscopic placement of self-expandable metallic stents is reportedly effective for gastric outlet obstructions due to advanced gastric cancer, and is less invasive than gastrojejunostomy. For patients who have good performance status, we administer chemotherapy after stent placement, although the safety and feasibility of this chemotherapy have not yet been discussed in full. Between 2011 and 2015, 15 patients at our institution underwent endoscopic gastroduodenal stent placement for gastric outlet obstruction due to gastric cancer. Eleven of these patients were administered chemotherapy after stent placement. In our case series, we did not observe any specific adverse event caused by stent placement plus chemotherapy. Adverse events after chemotherapy included anemia of CTCAE Grade 3 in 7 patients. Stent-in-stent placement was needed in 2 patients. Neither stent migration nor perforation was observed. Therefore, chemotherapy after stent placement for gastric outlet obstruction due to gastric cancer was considered safe and feasible. Stent placement is useful not only as palliative care for patients with terminal-stage disease, but also as one of the multimodal therapeutic strategies for gastric cancer.

34 CFR 379.10 - What types of project activities are required of each grantee under this program?

Code of Federal Regulations, 2010 CFR

2010-07-01

... placement and career advancement opportunities; (b) Provide job development, job placement, and career... job and career availability within the community, consistent with the current and projected local employment opportunities identified by the local workforce investment board for the community under section...

Kernel-Based Discriminant Techniques for Educational Placement

ERIC Educational Resources Information Center

Lin, Miao-hsiang; Huang, Su-yun; Chang, Yuan-chin

2004-01-01

This article considers the problem of educational placement. Several discriminant techniques are applied to a data set from a survey project of science ability. A profile vector for each student consists of five science-educational indicators. The students are intended to be placed into three reference groups: advanced, regular, and remedial.…

Environmental Impact Statement Space Shuttle Advanced Solid Rocket Motor Program

DTIC Science & Technology

1989-03-01

Space Shuttle solid rocket boosters are currently retrieved from the Atlantic Ocean after a launch and disassembled at KSC. It is assumed that the...testing is not anticipated to impact aquatic resources. The exhaust plume will be directed over the ocean , which has a high buffering capacity and mixing...approximately 30 miles. After being slowed by parachutes, the spent motors will fall into the ocean where they will be recovered and towed to a dock at

76 FR 3647 - Towing Safety Advisory Committee; Vacancies

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-20

... the Coast Guard on matters relating to shallow-draft inland and coastal waterway navigation and towing... Committee advises the Secretary of Homeland Security on matters relating to shallow-draft inland and coastal... operations associated with shallow-draft inland and coastal waterway navigation and towing safety. Registered...

46 CFR 27.101 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Definitions. 27.101 Section 27.101 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS TOWING VESSELS General Provisions for Fire-Protection... means a towing vessel that is not in ocean or coastal service. Towing vessel in ocean or coastal service...

46 CFR 27.101 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Definitions. 27.101 Section 27.101 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS TOWING VESSELS General Provisions for Fire-Protection... means a towing vessel that is not in ocean or coastal service. Towing vessel in ocean or coastal service...

Use of water towing tanks for aerodynamics and hydrodynamics

NASA Technical Reports Server (NTRS)

Gadelhak, Mohamed

1987-01-01

Wind tunnels and flumes have become standard laboratory tools for modeling a variety of aerodynamic and hydrodynamic flow problems. Less available, although by no means less useful, are facilities in which a model can be towed (or propelled) through air or water. This article emphasizes the use of the water towing tank as an experimental tool for aerodynamic and hydrodynamic studies. Its advantages and disadvantages over other flow rigs are discussed, and its usefullness is illustrated through many examples of research results obtained over the past few years in a typical towing tank facility.

Torsionally rigid support apparatus for marine seismic transducer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Myers, W.J.; Cole, J.H.

1989-11-14

This patent describes apparatus for supporting a marine seismic transducer from a vessel. It comprises: an elongated substantially rigid towing arm; a connector means for connecting the transducer to a lower end of the towing arm; a swivel member which is secured to the vessel and is pivotable about a generally horizontal first axis transverse to a length of the vessel; and a support means for pivotally connecting an upper end of the towing arm to the swivel member. The support means being pivotal relative to the swivel member about a second axis transverse to a longitudinal axis of themore » towing arm. The support means being substantially rigid so as to prevent any substantial rotation of the towing arm about its the longitudinal axis.« less

Effects of Fiber Coatings on Tensile Properties of Hi-Nicalon SiC/RBSN Tow Composites

NASA Technical Reports Server (NTRS)

Bhatt, Ramakrishna T.; Hull, David R.

1997-01-01

Uncoated Hi-Nicalon silicon carbide (SiC) fiber tows and those coated with a single surface layer of pyrolytic boron nitride (PBN), double layers of PBN/Si-rich PBN, and boron nitride (BN)/SiC coatings deposited by chemical vapor deposition (CVD) method were infiltrated with silicon slurry and then exposed to N2, for 4 hr at 1200 and 1400 C. Room temperature ultimate tensile fracture loads and microstructural characterization of uncoated and CVD coated Hi-Nicalon SiC fiber reinforced reaction-bonded silicon nitride (RBSN) tow composites were measured to select suitable interface coating(s) stable under RBSN processing conditions. Results indicate that room temperature ultimate fracture loads of the uncoated Hi-Nicalon SiC/RBSN tow composites nitrided at both temperatures were significantly lower than those of the uncoated Hi-Nicalon tows without slurry infiltration. In contrast, all CVD coated Hi-Nicalon SiC/RBSN tow composites retained a greater fraction of the dry tow fracture load after nitridation at 1200 C, but degraded significantly after nitridation at 1400 C. Reaction between metal impurities (Fe and Ni) present in the attrition milled silicon powder and uncoated regions of SiC fibers appears to be the probable cause for fiber degradation.

Stress-Dependent Matrix Cracking in 2D Woven SiC-Fiber Reinforced Melt-Infiltrated SiC Matrix Composites

NASA Technical Reports Server (NTRS)

Morscher, Gregory N.

2003-01-01

The matrix cracking of a variety of SiC/SiC composites has been characterized for a wide range of constituent variation. These composites were fabricated by the 2-dimensional lay-up of 0/90 five-harness satin fabric consisting of Sylramic fiber tows that were then chemical vapor infiltrated (CVI) with BN, CVI with SiC, slurry infiltrated with SiC particles followed by molten infiltration of Si. The composites varied in number of plies, the number of tows per length, thickness, and the size of the tows. This resulted in composites with a fiber volume fraction in the loading direction that ranged from 0.12 to 0.20. Matrix cracking was monitored with modal acoustic emission in order to estimate the stress-dependent distribution of matrix cracks. It was found that the general matrix crack properties of this system could be fairly well characterized by assuming that no matrix cracks originated in the load-bearing fiber, interphase, chemical vapor infiltrated Sic tow-minicomposites, i.e., all matrix cracks originate in the 90 degree tow-minicomposites or the large unreinforced Sic-Si matrix regions. Also, it was determined that the larger tow size composites had a much narrower stress range for matrix cracking compared to the standard tow size composites.

Project-based fieldwork: perspectives of graduate entry students and project sponsors.

PubMed

Fortune, Tracy; McKinstry, Carol

2012-08-01

This article builds on an earlier viewpoint regarding the need for project-focussed fieldwork. It presents the findings of an evaluative study into the value of project placements undertaken by final year graduate entry master's students as part of a capstone subject. The authors argue that provision of project placements enable impending graduates to develop and implement macro level strategies to develop prevention, resource and service development skills often required of contemporary occupational therapy practitioners. A qualitative approach is adopted. Student cohorts from 2005 and 2006 completed open-ended, written questionnaires, and agency project sponsors were interviewed to obtain their perspectives of the project placement experience. Despite some concern that project placements might be undertaken at the expense of 'clinical' placements these findings reveal that projects managed by students were perceived by services to add great value enabling them to advance important priorities. Students and sponsors highlighted a range of positive learning outcomes, including the ability to work collaboratively with supervisors and develop advanced communication skills and political acumen. The success of such placements depends on supportive supervision from academic staff. CONCLUSIONS AND SIGNIFICANCE OF THE STUDY: The findings promote project placements as a highly authentic aspect of work integrated learning enabling learners to draw together a range of attributes that support the ability to manage complex issues that have occupational relevance at a macro level. In addition, such experiences help learners to develop agency and political acumen both increasingly important capabilities for the contemporary workplace. © 2012 The Authors Australian Occupational Therapy Journal © 2012 Occupational Therapy Australia.

Percutaneous Nephrostomy: Technical Aspects and Indications

PubMed Central

Dagli, Mandeep; Ramchandani, Parvati

2011-01-01

First described in 1955 by Goodwin et al as a minimally invasive treatment for urinary obstruction causing marked hydronephrosis, percutaneous nephrostomy (PCN) placement quickly found use in a wide variety of clinical indications in both dilated and nondilated systems. Although the advancement of modern endourological techniques has led to a decline in the indications for primary nephrostomy placement, PCNs still play an important role in the treatment of multiple urologic conditions. In this article, the indications, placement, and postprocedure management of percutaneous nephrostomy drainage are described. PMID:23204641

Eclipse program QF-106 aircraft in flight

NASA Technical Reports Server (NTRS)

1997-01-01

This photo shows one of the QF-106s used in the Eclipse project in flight. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

77 FR 52317 - Record of Decision for Surveillance Towed Array Sensor System Low Frequency Active Sonar

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-29

... DEPARTMENT OF DEFENSE Department of the Navy Record of Decision for Surveillance Towed Array Sensor System Low Frequency Active Sonar AGENCY: Department of the Navy, DoD. ACTION: Notice of decision... to employ up to four Surveillance Towed Array Sensor System Low Frequency Active (SURTASS LFA) sonar...

33 CFR 83.35 - Sound signals in restricted visibility (Rule 35).

Code of Federal Regulations, 2010 CFR

2010-07-01

... engaged in fishing; vessels engaged in towing or pushing. A vessel not under command; a vessel restricted... fishing, whether underway or at anchor; and a vessel engaged in towing or pushing another vessel shall... made by the towing vessel. (e) Pushing and pushed vessels connected in composite unit. When a pushing...

Tow Tank Dynamic Test Rig Drawings and Bill of Materials for the Aquantis 2.5 MW Ocean Current Generation Device

DOE Data Explorer

Swales, Henry; Banko, Richard; Coakley, David

2015-06-03

Aquantis 2.5 MW Ocean Current Generation Device, Tow Tank Dynamic Test Rig Drawings and Bill of Materials. This submission contains information on the equipment for the scaled model tow tank testing. The information includes hardware, test protocols, and plans.

46 CFR 11.463 - General requirements for national endorsements as master, mate (pilot), and apprentice mate...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false General requirements for national endorsements as master... national endorsements as master, mate (pilot), and apprentice mate (steersman) of towing vessels. (a) The Coast Guard issues the following endorsements for towing vessels: (1) Master of towing vessels. (2...

46 CFR 15.610 - Master and mate (pilot) of towing vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Master and mate (pilot) of towing vessels. 15.610 Section 15.610 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; Uninspected Vessels § 15.610 Master and mate (pilot) of towing...

78 FR 14314 - Towing Safety Advisory Committee; Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-05

... Regarding Manning of Inspected Towing Vessels. On March 21, 2013 from 8 a.m. to 5:30 p.m. and on March 22... Vessels. An interim report will be given. (7) Recommendations regarding Manning of Inspected Towing...) Recommendations for the Standardization of Tug/Towboat Definitions, and; (3) Recommendations for Wake and Surge...

The Status of Infantry TOW, LAW, and Dragon Training in USAREUR.

DTIC Science & Technology

1977-11-01

TOW duties (guard, CQ runner , etc.); (b) Permanent assignment to other than TOW duties; (c) medical and dental appointments and drug and alcohol abuse...in training areas would be most helpful, and a third said American tanks and ve- hicles could be mocked-up to look like enemy targets and that kites

Electrically-Conductive Polyaramid Cable And Fabric

NASA Technical Reports Server (NTRS)

Orban, Ralph F.

1988-01-01

Tows coated with metal provide strength and conductance. Cable suitable for use underwater made of electrically conductive tows of metal-coated polyaramid filaments surrounded by electrically insulating jacket. Conductive tows used to make conductive fabrics. Tension borne by metal-coated filaments, so upon release, entire cable springs back to nearly original length without damage.

46 CFR 15.610 - Master and mate (pilot) of towing vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Master and mate (pilot) of towing vessels. 15.610 Section 15.610 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; Uninspected Vessels § 15.610 Master and mate (pilot) of towing...

46 CFR 15.610 - Master and mate (pilot) of towing vessels.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Master and mate (pilot) of towing vessels. 15.610 Section 15.610 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; Uninspected Vessels § 15.610 Master and mate (pilot) of towing...

46 CFR 15.610 - Master and mate (pilot) of towing vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Master and mate (pilot) of towing vessels. 15.610 Section 15.610 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; Uninspected Vessels § 15.610 Master and mate (pilot) of towing...

46 CFR 15.610 - Master and mate (pilot) of towing vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Master and mate (pilot) of towing vessels. 15.610 Section 15.610 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; Uninspected Vessels § 15.610 Master and mate (pilot) of towing...

49 CFR 393.43 - Breakaway and emergency braking.

Code of Federal Regulations, 2010 CFR

2010-10-01

... protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped with... protection valve or similar device shall operate automatically when the air pressure on the towing vehicle is... brake systems installed on towed vehicles shall be so designed, by the use of “no-bleed-back” relay...

49 CFR 393.43 - Breakaway and emergency braking.

Code of Federal Regulations, 2011 CFR

2011-10-01

... protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped with... protection valve or similar device shall operate automatically when the air pressure on the towing vehicle is... brake systems installed on towed vehicles shall be so designed, by the use of “no-bleed-back” relay...

Weavability of dry polymer powder towpreg

NASA Technical Reports Server (NTRS)

Hugh, Maylene K.; Marchello, Joseph M.; Maiden, Janice R.; Johnston, Norman J.

1993-01-01

Carbon fiber yarns (3k, 6k, 12k) were impregnated with LARC (tm) thermoplastic polyimide dry powder. Parameters for weaving these yarns were established. Eight-harness satin fabrics were successfully woven from each of the three classes of yarns and consolidated into test specimens to determine mechanical properties. It was observed that for optimum results warp yarns should have flexural rigidities between 10,000 and 100,000 mg-cm. Tow handling minimization, low tensioning, and tow bundle twisting were used to reduce fiber breakage, the separation of filaments, and tow-to-tow abrasion. No apparent effect of tow size or twist was observed on either tension or compression modulus. However, fiber damage and processing costs favor the use of 12k yarn bundles versus 3k or 6k yarn bundles in the weaving of powder-coated towpreg.

Eclipse project QF-106 and C-141A takeoff on first tethered flight December 20, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

TOW ROPE TAKEOFF - The Kelly Space & Technology (KST)/USAF Eclipse project's modified QF-106 and a USAF C-141A takeoff for the project's first tethered flight on December 20, 1997. The successful 18-minute-long flight reached an altitude of 10,000 feet. NASA's Dryden Flight Research Center, Edwards, California, hosted the project, providing engineering and facility support as well as the project pilot. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Effect of Test Specimen Shape and Size on Interlaminar Tensile Properties of Advanced Carbon-Carbon Composites

NASA Technical Reports Server (NTRS)

Vaughn, Wallace L.

2015-01-01

The interlaminar tensile strength of 1000-tow T-300 fiber ACC-6 carbon-carbon composites was measured using the method of bonding the coupons to adherends at room temperature. The size, 0.70 to 1.963 inches maximum width or radius, and shape, round or square, of the test coupons were varied to determine if the test method was sensitive to these variables. Sixteen total variations were investigated and the results modeled.

Percutaneous Irreversible Electroporation of Locally Advanced Pancreatic Carcinoma Using the Dorsal Approach: A Case Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scheffer, Hester J., E-mail: hj.scheffer@vumc.nl; Melenhorst, Marleen C. A. M., E-mail: m.melenhorst@vumc.nl; Vogel, Jantien A., E-mail: j.a.vogel@amc.uva.nl

Irreversible electroporation (IRE) is a novel image-guided ablation technique that is increasingly used to treat locally advanced pancreatic carcinoma (LAPC). We describe a 67-year-old male patient with a 5 cm stage III pancreatic tumor who was referred for IRE. Because the ventral approach for electrode placement was considered dangerous due to vicinity of the tumor to collateral vessels and duodenum, the dorsal approach was chosen. Under CT-guidance, six electrodes were advanced in the tumor, approaching paravertebrally alongside the aorta and inferior vena cava. Ablation was performed without complications. This case describes that when ventral electrode placement for pancreatic IRE is impaired,more » the dorsal approach could be considered alternatively.« less

Advanced Geophysical Classification with the Marine Towed Array

NASA Astrophysics Data System (ADS)

Steinhurst, D.; Harbaugh, G.; Keiswetter, D.; Bell, T. W.; Massey, G.; Wright, D.

2017-12-01

The Marine Towed Array, or MTA, is an underwater dual-mode sensor array that has been successfully deployed at multiple marine venues in support of Strategic Environmental Research and Development Program (SERDP) and Environmental Security Technology Certification Program (ESTCP) demonstrations beginning in 2004. It provided both marine electromagnetic and marine magnetic sensors for detection and mapping of underwater UXO. The EMI sensor array was based on older technology, which in several ESTCP demonstrations has not been able to support advanced geophysical classification (AGC). Under ESTCP funding, the U.S. Naval Research Laboratory is in the process of upgrading the MTA with modern, advanced electromagnetic (EMI) electronics and replacing the sensor array with a modern, multistatic array design. A half-scale version of the proposed array has been built and tested on land. Six tri-axial receiver cubes were placed inside two- and three- transmit coil configurations in equivalent positions to design locations for the MTA wing. The responses of a variety of munitions items and test spheres were measured over a range of target-to-array geometries and in both static and simulated dynamic data collection modes. The multi-transmit coil configuration was shown to provide enhanced single-pass classification performance over the original single coil design, particularly as a function of target location relative to the centerline. The ability to go beyond anomaly detection and additionally classify detected anomalies from survey data would dramatically improve the state of the art for underwater UXO remediation by reducing costs and improving the efficiency of these efforts. The results of our efforts to return the MTA to service and validating the new EMI array's design for UXO detection and classification in the underwater environment will be the focus of this presentation.

33 CFR 83.24 - Towing and pushing (Rule 24).

Code of Federal Regulations, 2012 CFR

2012-07-01

... line above the sternlight; and (5) When the length of the tow exceeds 200 meters, a diamond shape where... exceeds 200 meters, a diamond shape where it can best be seen. (f) Vessels being towed alongside or pushed... alongside each other shall be lighted as one vessel or object; (4) A diamond shape at or near the aftermost...

33 CFR 83.24 - Towing and pushing (Rule 24).

Code of Federal Regulations, 2013 CFR

2013-07-01

... line above the sternlight; and (5) When the length of the tow exceeds 200 meters, a diamond shape where... exceeds 200 meters, a diamond shape where it can best be seen. (f) Vessels being towed alongside or pushed... alongside each other shall be lighted as one vessel or object; (4) A diamond shape at or near the aftermost...

System and Method for Air Launch from a Towed Aircraft

NASA Technical Reports Server (NTRS)

Budd, Gerald D (Inventor)

2018-01-01

The invention is a system and method of air launching a powered launch vehicle into space or high altitude. More specifically, the invention is a tow aircraft which tows an unpowered glider, with the powered launch vehicle attached thereto, to launch altitude. The powered launch vehicle is released from the unpowered glider and powered on for launch.

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

46 CFR 11.464 - Requirements for national endorsements as master of towing vessels.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Requirements for national endorsements as master of... Deck Officer Endorsements § 11.464 Requirements for national endorsements as master of towing vessels. (a) An applicant for an endorsement as master of towing vessels with a route listed in column 1 of...

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... damage; and (3) Be installed in a manner that prevents it from contacting the vehicle's exhaust system or... connections. All connections for air, vacuum, or hydraulic braking systems shall be installed so as to ensure... may be used for connections between towed and towing motor vehicles or between the frame of a towed...

Content Selection in Advanced Courses

ERIC Educational Resources Information Center

Parker, Walter C.; Lo, Jane C.

2016-01-01

Advanced high-school courses, such as Advanced Placement (AP) courses in the United States, present a content selection conundrum of major proportions. Judicious content selection is necessary if students are to learn subject matter meaningfully, but the sheer breadth of tested material in these courses promotes nearly the opposite:…

Does a tow-bar increase the risk of neck injury in rear-end collisions?

PubMed

Olesen, Anne Vingaard; Elvik, Rune; Andersen, Camilla Sloth; Lahrmann, Harry S

2018-06-01

Does a tow-bar increase the risk of neck injury in the struck car in a rear-end collision? The rear part of a modern car has collision zones that are rendered nonoperational when the car is equipped with a tow-bar. Past crash tests have shown that a car's acceleration was higher in a car equipped with a tow-bar and also that a dummy placed in a car with a tow-bar had higher peak acceleration in the lower neck area. This study aimed to investigate the association between the risk of neck injury in drivers and passengers, and the presence of a registered tow-bar on the struck car in a rear-end collision. We performed a merger of police reports, the National Hospital Discharge Registry, and the National Registry of Motor Vehicles in Denmark. We identified 9,370 drivers and passengers of whom 1,519 were diagnosed with neck injury within the first year after the collision. We found a statistically insignificant 5% decrease in the risk of neck injury in the occupants of the struck car when a tow-bar was fitted compared to when it was not fitted (hazard ratio=0.95; 95% confidence level=0.85-1.05; p=0.32). The result was controlled for gender, age, and the seat of the occupant. Several other collision and car characteristics and demographic information on the drivers and passengers were evaluated as confounders but were not statistically significant. The present study may serve as valuable input for a meta-analysis on the effect of a tow-bar because negative results are necessary in order to avoid publication bias. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Wind-Tunnel Investigation of a Balloon as a Towed Decelerator at Mach Numbers from 1.47 to 2.50

NASA Technical Reports Server (NTRS)

McShera, John T.; Keyes, J. Wayne

1961-01-01

A wind-tunnel investigation has been conducted to study the characteristics of a towed spherical balloon as a drag device at Mach numbers from 1.47 to 2.50, Reynolds numbers from 0.36 x 10(exp 6) to 1.0 x 10(exp 6) , and angles of attack from -15 to 15 deg. Towed spherical balloons were found to be stable at supersonic speeds. The drag coefficient of the balloon is reduced by the presence of a tow cable and a further reduction occurs with the addition of a payload. The balloon inflation pressure required to maintain an almost spherical shape is about equal to the free-stream dynamic pressure. Measured pressure and temperature distribution around the balloon alone were in fair agreement with predicted values. There was a pronounced decrease in the pressure coefficients on the balloon when attached to a tow cable behind a payload.

Wind Tunnel Investigation of a Balloon as Decelerator at Mach Numbers from 1.47 to 2.50

NASA Technical Reports Server (NTRS)

McShera, John T.; Keyes, J. Wayne

1961-01-01

A wind-tunnel investigation was conducted to study the characteristics of a towed spherical balloon as a drag device at Mach numbers from 1.47 to 2.50, Reynolds numbers from 0.36 x 10(exp 6) to 1.0 x 10(exp 6) , and angles of attack from -15 to 15 degrees. Tow-cable length was approximately 24 inches from asymmetric body to cone on the upstream side of the balloon. As the tow cable was lengthened the balloon reached a point in the test section where wall-reflected shocks intersected the balloon and caused severe oscillations. As a result, the tow cable broke and the inflatable balloon model was destroyed. Further tests used a model rigid plastic sphere 6.75 inches in diameter. Tow cable length was approximately 24 inches from asymmetric body to the upstream side of the sphere.

Advanced Course Enrollment and Performance among English Learner Students in Washington State. REL 2017-187

ERIC Educational Resources Information Center

Hanson, Havala; Bisht, Biraj; Motamedi, Jason Greenberg

2016-01-01

Taking advanced high school courses (for example, honors, Advanced Placement, and dual-credit courses that offer college credits in high school) can help prepare students for postsecondary education and careers. English learner students, however, face unique obstacles to taking advanced courses because they must divide their time between acquiring…

Technology: The Silent Partner in the Advancement of Measurement and Assessment Practices (A Student Centered Assessment Model).

ERIC Educational Resources Information Center

Blanzy, James J.; Sucher, Joseph E.

Michigan's Macomb Community College's institutional assessment model involves using technology to collect and disseminate data on student learning in order to facilitate continuous improvement and adaptation. The first element of this five-part model is the mandatory testing, orientation, and placement of incoming students. Using placement test…

Impacts of a Summer Bridge Program in Engineering on Student Retention and Graduation

ERIC Educational Resources Information Center

Cançado, Luciana; Reisel, John R.; Walker, Cindy M.

2018-01-01

A summer bridge program was developed in an engineering program to advance the preparation of incoming freshmen students, particularly with respect to their math course placement. The program was intended to raise the initial math course placement of students who otherwise would begin their engineering studies in courses below Calculus I. One…

Determinants of High Schools' Advanced Course Offerings

ERIC Educational Resources Information Center

Iatarola, Patrice; Conger, Dylan; Long, Mark C.

2011-01-01

This article examines the factors that determine a high school's probability of offering Advanced Placement (AP) and International Baccalaureate (IB) courses. The likelihood that a school offers advanced courses, and the number of sections that it offers, is largely driven by having a critical mass of students who enter high school with…

46 CFR 31.15-10 - Towing vessels may carry persons in addition to crew-B/LBR.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Towing vessels may carry persons in addition to crew-B/LBR. 31.15-10 Section 31.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS INSPECTION AND CERTIFICATION Manning of Tank Vessels § 31.15-10 Towing vessels may carry persons in addition...

46 CFR 31.15-10 - Towing vessels may carry persons in addition to crew-B/LBR.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Towing vessels may carry persons in addition to crew-B/LBR. 31.15-10 Section 31.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS INSPECTION AND CERTIFICATION Manning of Tank Vessels § 31.15-10 Towing vessels may carry persons in addition...

46 CFR 31.15-10 - Towing vessels may carry persons in addition to crew-B/LBR.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Towing vessels may carry persons in addition to crew-B/LBR. 31.15-10 Section 31.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS INSPECTION AND CERTIFICATION Manning of Tank Vessels § 31.15-10 Towing vessels may carry persons in addition...

46 CFR 31.15-10 - Towing vessels may carry persons in addition to crew-B/LBR.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Towing vessels may carry persons in addition to crew-B/LBR. 31.15-10 Section 31.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS INSPECTION AND CERTIFICATION Manning of Tank Vessels § 31.15-10 Towing vessels may carry persons in addition...

46 CFR 31.15-10 - Towing vessels may carry persons in addition to crew-B/LBR.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Towing vessels may carry persons in addition to crew-B/LBR. 31.15-10 Section 31.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS INSPECTION AND CERTIFICATION Manning of Tank Vessels § 31.15-10 Towing vessels may carry persons in addition...

76 FR 36314 - Safety Zone; Mile Marker 98.5 West of Harvey Lock Gulf Intracoastal Waterway to Mile Marker 108.5...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-22

..., levee system, vessels and tows from destruction, loss or injury due to hazards associated with rising... the general public, levee system, vessels and tows from the hazards associated with rising flood water... system, vessels and tows from destruction, loss or injury due to the hazards associated with rising flood...

49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

Code of Federal Regulations, 2012 CFR

2012-10-01

... may be used for connections between towed and towing motor vehicles or between the frame of a towed... in a spring guard or similar device which prevents the tubing from kinking at the fitting at which it is attached to the vehicle; and (2) The spring guard or similar device has at least 51 mm (2 inches...

M2-F1 in flight over lakebed on tow line

NASA Image and Video Library

1963-08-30

Following the first M2-F1 airtow flight on 16 August 1963, the Flight Research Center used the vehicle for both research flights and to check out new lifting-body pilots. These included Bruce Peterson, Don Mallick, Fred Haise, and Bill Dana from NASA. Air Force pilots who flew the M2-F1 included Chuck Yeager, Jerry Gentry, Joe Engle, Jim Wood, and Don Sorlie, although Wood, Haise, and Engle only flew on car tows. In the three years between the first and last flights of the M2-F1, it made about 400 car tows and 77 air tows.

Impact damage resistance of composite fuselage structure, part 1

NASA Technical Reports Server (NTRS)

Dost, E. F.; Avery, W. B.; Ilcewicz, L. B.; Grande, D. H.; Coxon, B. R.

1992-01-01

The impact damage resistance of laminated composite transport aircraft fuselage structures was studied experimentally. A statistically based designed experiment was used to examine numerous material, laminate, structural, and extrinsic (e.g., impactor type) variables. The relative importance and quantitative measure of the effect of each variable and variable interactions on responses including impactor dynamic response, visibility, and internal damage state were determined. The study utilized 32 three-stiffener panels, each with a unique combination of material type, material forms, and structural geometry. Two manufacturing techniques, tow placement and tape lamination, were used to build panels representative of potential fuselage crown, keel, and lower side-panel designs. Various combinations of impactor variables representing various foreign-object-impact threats to the aircraft were examined. Impacts performed at different structural locations within each panel (e.g., skin midbay, stiffener attaching flange, etc.) were considered separate parallel experiments. The relationship between input variables, measured damage states, and structural response to this damage are presented including recommendations for materials and impact test methods for fuselage structure.

Ohmsett test of NOFI Vee-Sweep and NOFI 600S oilboom. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goodwin, M.J.

1993-10-01

A NOFI Vee-Sweep and a NOFI 600S Oilboom, both manufactured by NOFI TROMSO A/S of Norway, were tested at the Ohmsett test tank in Leonardo, NJ. The V-Shaped Sweep is an oil boom designed for use with a skimmer at the apex of the V-Shaped configuration. Oil is funneled back to the skimmer by the converging sides of the V and concentrated for more efficient skimming. The 60 meter length of the sweep is doubled over to form the V and held in this shape by cross netting at the bottom of the skirt. The bottom netting is claimed tomore » help stabilize the oil in the sweep. The sweep was towed with a 700mm skirt depth and mouth opening of 16 meters. The mouth opening was reduced from the designed 19.8 meters to fit in the tow tank without causing excess blockage. The limiting towing speeds of the sweep were determined with and without oil present, in calm water and in small waves. The sweep's ability to conform to waves was also determined. Towing forces were measured. Limited data on oil loss rates were obtained. Testing confirmed the manufacturer's claim that the sweep can be towed at 1.0 and 1.4 knots with oil in calm water, based on the first loss of oil. The critical tow speed was found to be 3.4 to 3.6 knots in calm water. Oil booms, Tow tank testing.« less

Modified fully covered self-expandable metal stents with antimigration features for benign pancreatic-duct strictures in advanced chronic pancreatitis, with a focus on the safety profile and reducing migration.

PubMed

Moon, Sung-Hoon; Kim, Myung-Hwan; Park, Do Hyun; Song, Tae Joon; Eum, Junbum; Lee, Sang Soo; Seo, Dong Wan; Lee, Sung Koo

2010-07-01

Fully covered self-expandable metal stent (FCSEMS) placement has recently been tried in the management of refractory pancreatic-duct strictures associated with advanced chronic pancreatitis. The major limitation of FCSEMSs was frequent migration. To assess the safety, migration rate, and removability of modified FCSEMSs with antimigration features used for the treatment of benign pancreatic-duct strictures. Prospective study. Tertiary academic center. Thirty-two patients with chronic painful pancreatitis and dominant ductal stricture. Transpapillary endoscopic placement of FCSEMSs in the pancreatic duct with removal after 3 months. Technical and functional success and adverse events associated with the placement of metal stents. FCSEMSs were successfully placed in all patients through the major (n = 27) or minor (n = 5) duodenal papilla. All patients achieved pain relief from stent placement. There was no occurrence of stent-induced pancreatitis or pancreatic sepsis. No stent migrated, and all stents were easily removed. Follow-up ERCP 3 months after stent placement showed resolution of duct strictures in all patients. Pancreatograms obtained at FCSEMS removal displayed de novo focal pancreatic duct strictures in 5 patients, but all were asymptomatic. No long-term follow-up. Temporary 3-month placement of FCSEMSs was effective in resolving pancreatic-duct strictures in chronic pancreatitis, with an acceptable morbidity profile. Modified FCSEMSs can prevent stent migration, but may be associated with de novo duct strictures. Further trials are needed to assess long-term safety and efficacy. Copyright 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Adhesion at the interface in cured graphite fiber epoxy-amine resin composites

NASA Technical Reports Server (NTRS)

Needles, Howard L.; Alger, Kenneth W.; Okamoto, Robert

1987-01-01

The effect of high temperature curing on the interface between unsized or epoxy-sized graphite fiber tow and epoxy-amine resin was examined by scanning electron microscopy of compression and freeze fractured specimens. Little or no adhesion was found between the unsized graphite fiber tows and the epoxy-amine resin on curing at 165 C for 17 hrs. Epoxy-sized graphite fibers showed a similar lack of adhesion between the fiber tows and the epoxy-amine resin at 3 and 17 hr cures, although good penetration of the resin into the sized fiber tows had occurred. Interfacial bond strengths for the composites could not be effectively measured by compression fracture of specimens.

The History of Nontraditional or Ectopic Placement of Reservoirs in Prosthetic Urology.

PubMed

Perito, Paul; Wilson, Steven

2016-04-01

Reservoir placement during implantation of prosthetic urology devices has been problematic throughout the history of the surgical treatment of erectile dysfunction and urinary incontinence. We thought it would be interesting to review the history of reservoir placement leading up to current surgical techniques. To provide an overview of the past and present techniques for reservoir placement and discuss the evolutionary process leading to safe and effective placement of prosthetic reservoirs. We reviewed data pertaining to inflatable penile prosthesis (IPP) reservoirs and pressure-regulating balloons (PRB) in a chronological fashion, spanning 25 years. Main outcomes included a historical review of techniques for IPP reservoir and PRB placement leading to the subsequent incremental improvements in safety and efficacy when performing penile implants and artificial urinary sphincters. Prosthetic urologic reservoirs have traditionally been placed in the retropubic space. Over the years, urologists have attempted use of alternative spaces including peritoneal, epigastric, "ectopic," posterior to transversalis, and high submuscular. Current advances in prosthetic urologic reservoir placement allow safe and effective abdominal wall placement of reservoirs. These novel approaches appear to be so effective that urologists may now be able to cease using the traditional retropubic space for reservoir placement, even in the case of virgin pelves. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

The Role of Advanced High School Coursework in Increasing STEM Career Interest

ERIC Educational Resources Information Center

Sadler, Philip M.; Sonnert, Gerhard; Hazari, Zahra; Tai, Robert

2014-01-01

Several avenues are open to students who wish to study advanced science or mathematics in high school, which include Advanced Placement courses and teacher-designed courses unaffiliated with organized programs. We employ a retrospective cohort study of 4,691 nationally representative college students at 34 randomly selected, colleges and…

Advanced Academic Participation: A Longitudinal Analysis of Ethnicity Gaps in Suburban Schools

ERIC Educational Resources Information Center

Kettler, Todd; Hurst, Luke T.

2017-01-01

Participation in advanced academic programs such as Advanced Placement (AP) and International Baccalaureate (IB) has been associated with higher student achievement and college readiness. In addition, AP and IB are widely recommended and implemented as services for gifted and talented students. Students who participate in these programs tend to be…

Influence of Tow Architecture on Compaction and Nesting in Textile Preforms

NASA Astrophysics Data System (ADS)

Yousaf, Z.; Potluri, P.; Withers, P. J.

2017-04-01

Transverse compression response of tows during processes such as vacuum infusion or autoclave curing has significant influence on resin permeability in fabrics as well as the laminate thickness, fibre volume fraction and tow orientations in the finished composite. This paper reports macro -scale deformations in dry fibre assemblies due to transverse compaction. In this study, influence of weave geometry and the presence of interlacements or stitches on the ply-level compaction as well as nesting have been investigated. 2D woven fabrics with a variety of interlacement patterns - plain, twill and sateen- as well as stitched Non-crimp (NCF) fabrics have been investigated for macro-level deformations. Compression response of single layer and multilayer stacks has been studied as a function of external pressure in order to establish nesting behaviour. It appears that the degree of individual ply compaction and degree of nesting between the plies are influenced by tow architectures. Inter-tow spacing and stitching thread thickness appears to influence the degree of nesting in non-crimp fabrics.

Process for preparing tapes from thermoplastic polymers and carbon fibers

NASA Technical Reports Server (NTRS)

Chung, Tai-Shung (Inventor); Furst, Howard (Inventor); Gurion, Zev (Inventor); McMahon, Paul E. (Inventor); Orwoll, Richard D. (Inventor); Palangio, Daniel (Inventor)

1986-01-01

The instant invention involves a process for use in preparing tapes or rovings, which are formed from a thermoplastic material used to impregnate longitudinally extended bundles of carbon fibers. The process involves the steps of (a) gas spreading a tow of carbon fibers; (b) feeding the spread tow into a crosshead die; (c) impregnating the tow in the die with a thermoplastic polymer; (d) withdrawing the impregnated tow from the die; and (e) gas cooling the impregnated tow with a jet of air. The crosshead die useful in the instant invention includes a horizontally extended, carbon fiber bundle inlet channel, means for providing melted polymer under pressure to the die, means for dividing the polymeric material flowing into the die into an upper flow channel and a lower flow channel disposed above and below the moving carbon fiber bundle, means for applying the thermoplastic material from both the upper and lower channels to the fiber bundle, and means for withdrawing the resulting tape from the die.

Automated Finite Element Analysis of Elastically-Tailored Plates

NASA Technical Reports Server (NTRS)

Jegley, Dawn C. (Technical Monitor); Tatting, Brian F.; Guerdal, Zafer

2003-01-01

A procedure for analyzing and designing elastically tailored composite laminates using the STAGS finite element solver has been presented. The methodology used to produce the elastic tailoring, namely computer-controlled steering of unidirectionally reinforced composite material tows, has been reduced to a handful of design parameters along with a selection of construction methods. The generality of the tow-steered ply definition provides the user a wide variety of options for laminate design, which can be automatically incorporated with any finite element model that is composed of STAGS shell elements. Furthermore, the variable stiffness parameterization is formulated so that manufacturability can be assessed during the design process, plus new ideas using tow steering concepts can be easily integrated within the general framework of the elastic tailoring definitions. Details for the necessary implementation of the tow-steering definitions within the STAGS hierarchy is provided, and the format of the ply definitions is discussed in detail to provide easy access to the elastic tailoring choices. Integration of the automated STAGS solver with laminate design software has been demonstrated, so that the large design space generated by the tow-steering options can be traversed effectively. Several design problems are presented which confirm the usefulness of the design tool as well as further establish the potential of tow-steered plies for laminate design.

Deep-towed CSEM survey of gas hydrates in the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Kannberg, P.; Constable, S.

2017-12-01

Controlled source electromagnetic (CSEM) surveys are increasingly being used to remotely detect hydrate deposits in seafloor sediments. CSEM methods are sensitive to sediment pore space resistivity, such as when electrically resistive hydrate displaces the electrically conductive pore fluid, increasing the bulk resistivity of the sediment. In July 2017, a two-week research cruise using an upgraded and expanded "Vulcan" towed receiver system collected over 250 line km of data at four sites in the Gulf of Mexico (GoM) thought to have hydrate bearing sediments. Hydrate bearing horizons at the survey sites ranged from 400-700 m below seafloor. Modeling suggested an array with source receiver offsets of up to 1600 m would be needed to properly image the deep hydrate. A deep towed electromagnetic transmitter outputting 270 Amps was towed 100 m above seafloor. Six Vulcan receivers, each recording three-axis electric field data, were towed at 200 m intervals from 600-1600 m behind the transmitter. The four sites surveyed, Walker Ridge 313, Orca Basin, Mad Dog, and Green Canyon 955, are associated with the upcoming GOM^2 coring operation scheduled for 2020. Wells at WR313 and GC955 were logged as part of a joint industry drilling project in 2009 and will be used to ground truth our inversion results. In 2008, WR313 and GC955 were surveyed using traditional CSEM seafloor receivers, accompanied by a single prototype Vulcan towed receiver. This prior survey will allow comparison of results from a seafloor receiver survey with those from a towed receiver survey. Seismic data has been collected at all the sites, which will be used to constrain inversions. In addition to the four hydrate sites surveyed, two lines were towed over Green Knoll, a deep-water salt dome located between Mad Dog and GC955. Presented here are initial results from our recent cruise.

Manufacturing of Smart Structures Using Fiber Placement Manufacturing Processes

NASA Technical Reports Server (NTRS)

Thomas, Matthew M.; Glowasky, Robert A.; McIlroy, Bruce E.; Story, Todd A.

1996-01-01

Smart structures research and development, with the ultimate aim of rapid commercial and military production of these structures, are at the forefront of the Synthesis and Processing of Intelligent Cost-Effective Structures (SPICES) program. As part of this ARPA-sponsored program, MDA-E is using fiber placement processes to manufacture integrated smart structure systems. These systems comprise advanced composite structures with embedded fiber optic sensors, shape memory alloys, piezoelectric actuators, and miniature accelerometers. Cost-effective approaches and solutions to smart material synthesis in the fiber-placement process, based upon integrated product development, are discussed herein.

Her physics, his physics: gender issues in Israeli advanced placement physics classes

NASA Astrophysics Data System (ADS)

Zohar, Anat

2003-02-01

Gender gaps in physics in favour of boys are more prominent in Israel than in other countries. The main research question is to find out what gender issues are at play in Israeli advanced placement physics classes. Matriculation exam scores from approximately 400 high schools were analysed across 12 years. In addition, semi-constructed interviews were conducted with 50 advanced placement physics students (25 girls and 25 boys). In terms of participation, it was found that the ratio of girls to boys has been unchanged from 1988 to 2000 and is roughly 1:3. In terms of performance, it was found that the final matriculation scores of boys and girls are similar. However, breaking up the final scores into its two components - teachers' given grades and matriculation test scores - showed that boy's test scores are usually higher than girls' test scores, while girls' teachers' given grades are usually higher than boys'. Results from semi-constructed interviews pointed to two factors that are especially unfavourable to many girls: excessive competitiveness and lack of teaching for understanding. Girls' yearning for deep understanding is seen as a form of questing for connected knowledge. It is suggested that instructional methods that foster students' understanding while decreasing competitiveness in physics classes might contribute to girls' participation and performance in advanced physics classes while also supporting the learning of many boys.

Simulated Tank Anti-Armor Gunnery System (STAGS-TOW).

DTIC Science & Technology

1983-05-01

to train TOW gunners. It is derived from a model previously developed for DRAGON. The system employs a terrain board with model enemy armored vehicles ...gunnery training. TOW is a crew-portable, heavy anti-tank weapon designed to attack and defeat armored vehicles and field fortifications. The missile is...a target area, converts the infrared energy to electrical signals and then to visible light and displays the visible light as a real-time scene for

Paresev 1 in Landing

NASA Image and Video Library

1962-02-05

Pilot and Paresev 1 preparing for a landing on the Rogers dry lakebed in 1962 at Edwards Air Force Base, California. The flight program began with ground tow tests. Several tows were made before liftoff was attempted to check the control rigging and to familiarize the pilot with the vehicle’s ground stability. As the pilot’s confidence and experience increased, tow speeds were also increased until liftoff was attained. Liftoff was at about 40 knots indicated airspeed (kias).

Process of Making Boron-Fiber Reinforced Composite Tape

NASA Technical Reports Server (NTRS)

Belvin, Harry L. (Inventor); Cano, Roberto J. (Inventor); Johnston, Norman J. (Inventor); Marchello, Joseph M. (Inventor)

2002-01-01

The invention is an apparatus and method for producing a hybrid boron reinforced polymer matrix composition from powder pre-impregnated fiber tow bundles and a linear array of boron fibers. The boron fibers are applied onto the powder pre-impregnated fiber tow bundles and then are processed within a processing component having an impregnation bar assembly. After passing through variable-dimension forming nip-rollers, the powder pre-impregnated fiber tow bundles with the boron fibers become a hybrid boron reinforced polymer matrix composite tape. A driving mechanism pulls the powder pre-impregnated fiber tow bundles with boron fibers through the processing line of the apparatus and a take-up spool collects the formed hybrid boron-fiber reinforced polymer matrix composite tape.

Micro-shimmy of towed structures in experimentally uncharted unstable parameter domain

NASA Astrophysics Data System (ADS)

Takács, Dénes; Stépán, Gábor

2012-11-01

In this paper, the lateral instability of towed structures (trailers, caravans and articulated buses) is investigated with special attention to the small amplitude lateral vibration that leads to a higher energy consumption in certain parameter domains. A low degree-of-freedom mechanical model of a shimmying towed tyre is used that describes the dynamics of the tyre-ground contact patch by the time delayed differential equation. Stability charts are calculated and the theoretically predicted linear unstable islands of small amplitude shimmy motions are validated by laboratory experiments. A tyre is towed by a relatively long caster, and its temperature and the input current of the conveyor belt are measured in order to show the increased value of the rolling resistance.

A Fragile Coalition: University and High School.

ERIC Educational Resources Information Center

Smith, Eugene

1981-01-01

Since 1978, the University of Washington has offered two of its freshman writing courses at Sequim High School, for advanced students wishing to earn college credit. The author discusses program's operations, advantages, and disadvantages, and compares it to the Advanced Placement Program. (SJL)

Advanced High School Biology in an Era of Rapid Change: A Summary of the Biology Panel Report from the NRC Committee on Programs for Advanced Study of Mathematics and Science in American High Schools

ERIC Educational Resources Information Center

Wood, William B.

2002-01-01

A recently released National Research Council (NRC) report, "Learning and Understanding: Improving Advanced Study of Mathematics and Science in U.S. High Schools", evaluated and recommended changes in the Advanced Placement (AP), International Baccalaureate (IB), and other advanced secondary school science programs. As part of this study,…

Advanced Coursework Rates by Ethnicity: An 11-Year, Statewide Analysis

ERIC Educational Resources Information Center

Fowler, Janis C.

2013-01-01

Purpose: The purpose of this study was to examine advanced coursework completion rates, Advanced Placement (AP)/International Baccalaureate (IB) testing rates, AP/IB exam passage rates, and the percentage of AP/IB exam scores at or above the criterion that may exist among Texas public high school students from 2001 to 2012 to ascertain (a) the…

M2-F1 in flight over lakebed on tow line

NASA Technical Reports Server (NTRS)

1963-01-01

After initial ground-tow flights of the M2-F1 using the Pontiac as a tow vehicle, the way was clear to make air tows behind a C-47. The first air tow took place on 16 August 1963. Pilot Milt Thompson found that the M2-F1 flew well, with good control. This first flight lasted less than two minutes from tow-line release to touchdown. The descent rate was 4,000 feet per minute. The wingless, lifting body aircraft design was initially concieved as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Dryden management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. This vehicle needed to be able to tow the M2-F1 on the Rogers Dry Lakebed adjacent to NASA's Flight Research Center (FRC) at a minimum speed of 100 miles per hour. To do that, it had to handle the 400-pound pull of the M2-F1. Walter 'Whitey' Whiteside, who was a retired Air Force maintenance officer working in the FRC's Flight Operations Division, was a dirt-bike rider and hot-rodder. Together with Boyden 'Bud' Bearce in the Procurement and Supply Branch of the FRC, Whitey acquired a Pontiac Catalina convertible with the largest engine available. He took the car to Bill Straup's renowned hot-rod shop near Long Beach for modification. With a special gearbox and racing slicks, the Pontiac could tow the 1,000-pound M2-F1 110 miles per hour in 30 seconds. It proved adequate for the roughly 400 car tows that got the M2-F1 airborne to prove it could fly safely and to train pilots before they were towed behind a C-47 aircraft and released. These initial car-tow tests produced enough flight data about the M2-F1 to proceed with flights behind the C-47 tow plane at greater altitudes. The C-47 took the craft to an altitude of 12,000 where free flights back to Rogers Dry Lake began. Pilot for the first series of flights of the M2-F1 was NASA research pilot Milt Thompson. Typical glide flights with the M2-F1 lasted about two minutes and reached speeds of 110 to l20 mph. A small solid landing rocket, referred to as the 'instant L/D rocket,' was installed in the rear base of the M2-F1. This rocket, which could be ignited by the pilot, provided about 250 pounds of thrust for about 10 seconds. The rocket could be used to extend the flight time near landing if needed. More than 400 ground tows and 77 aircraft tow flights were carried out with the M2-F1. The success of Dryden's M2-F1 program led to NASA's development and construction of two heavyweight lifting bodies based on studies at NASA's Ames and Langley research centers--the M2-F2 and the HL-10, both built by the Northrop Corporation, and the U.S. Air Force's X-24 program, with an X-24A and -B built by Martin. The Lifting Body program also heavily influenced the Space Shuttle program. The M2-F1 program demonstrated the feasibility of the lifting body concept for horizontal landings of atmospheric entry vehicles. It also demonstrated a procurement and management concept for prototype flight test vehicles that produced rapid results at very low cost (approximately $50,000, excluding salaries of government employees assigned to the project).

Advanced CD-SEM solution for edge placement error characterization of BEOL pitch 32nm metal layers

NASA Astrophysics Data System (ADS)

Charley, A.; Leray, P.; Lorusso, G.; Sutani, T.; Takemasa, Y.

2018-03-01

Metrology plays an important role in edge placement error (EPE) budgeting. Control for multi-patterning applications as new critical distances needs to be measured (edge to edge) and requirements become tighter and tighter in terms of accuracy and precision. In this paper we focus on imec iN7 BEOL platform and particularly on M2 patterning scheme using SAQP + block EUV for a 7.5 track logic design. Being able to characterize block to SAQP edge misplacement is important in a budgeting exercise (1) but is also extremely difficult due to challenging edge detection with CD-SEM (similar materials, thin layers, short distances, 3D features). In this study we develop an advanced solution to measure block to SAQP placement, we characterize it in terms of sensitivity, precision and accuracy through the comparison to reference metrology. In a second phase, the methodology is applied to budget local effects and the results are compared to the characterization of the SAQP and block independently.

Development of Deep-tow Autonomous Cable Seismic (ACS) for Seafloor Massive Sulfides (SMSs) Exploration.

NASA Astrophysics Data System (ADS)

Asakawa, Eiichi; Murakami, Fumitoshi; Tsukahara, Hitoshi; Saito, Shutaro; Lee, Sangkyun; Tara, Kenji; Kato, Masafumi; Jamali Hondori, Ehsan; Sumi, Tomonori; Kadoshima, Kazuyuki; Kose, Masami

2017-04-01

Within the EEZ of Japan, numerous surveys exploring ocean floor resources have been conducted. The exploration targets are gas hydrates, mineral resources (manganese, cobalt or rare earth) and especially seafloor massive sulphide (SMS) deposits. These resources exist in shallow subsurface areas in deep waters (>1500m). For seismic explorations very high resolution images are required. These cannot be effectively obtained with conventional marine seismic techniques. Therefore we have been developing autonomous seismic survey systems which record the data close to the seafloor to preserve high frequency seismic energy. Very high sampling rate (10kHz) and high accurate synchronization between recording systems and shot time are necessary. We adopted Cs-base atomic clock considering its power consumption. At first, we developed a Vertical Cable Seismic (VCS) system that uses hydrophone arrays moored vertically from the ocean bottom to record close to the target area. This system has been successfully applied to SMS exploration. Specifically it fixed over known sites to assess the amount of reserves with the resultant 3D volume. Based on the success of VCS, we modified the VCS system to use as a more efficient deep-tow seismic survey system. Although there are other examples of deep-tow seismic systems, signal transmission cables present challenges in deep waters. We use our autonomous recording system to avoid these problems. Combining a high frequency piezoelectric source (Sub Bottom Profiler:SBP) that automatically shots with a constant interval, we achieve the high resolution deep-tow seismic without data transmission/power cable to the board. Although the data cannot be monitored in real-time, the towing system becomes very simple. We have carried out survey trial, which showed the systems utility as a high-resolution deep-tow seismic survey system. Furthermore, the frequency ranges of deep-towed source (SBP) and surface towed sparker are 700-2300Hz and 10-200Hz respectively. Therefore we can use these sources simultaneously and distinguish the records of each source in the data processing stage. We have developed new marine seismic survey systems with autonomous recording for the exploration of the ocean floor resources. The applications are vertical cable seismic (VCS) and deep-tow seismic (ACS). These enable us the recording close to the seafloor and give the high resolution results with a simple, cost-effective configuration.

Freedom Star tows a barge with an SLWT into Port Canaveral for the first time

NASA Technical Reports Server (NTRS)

1998-01-01

Freedom Star, one of NASA's two solid rocket booster recovery ships, tows a barge containing the third Space Shuttle super lightweight external tank (SLWT) into Port Canaveral. This SLWT will be used to launch the orbiter Discovery on mission STS-95 in October. This first-time towing arrangement, part of a cost savings plan by NASA to prudently manage existing resources, began June 12 from the Michoud Assembly Facility in New Orleans where the Shuttle's external tanks are manufactured. The barge will now be transported up the Banana River to the LC-39 turn basin using a conventional tugboat. Previously, NASA relied on an outside contractor to provide external tank towing services at a cost of about $120,000 per trip. The new plan allows NASA's Space Flight Operations contractor, United Space Alliance (USA), to provide the same service directly to NASA using the recovery ships during their downtime between Shuttle launches. Studies show a potential savings of about $50,000 per trip. The cost of the necessary ship modifications should be paid back by the fourteenth tank delivery. The other recovery ship, Liberty Star, has also undergone deck strengthening enhancements and will soon have the necessary towing winch installed. The other recovery vessel, Liberty Star, has undergone deck strengthening enhancements along with Freedom Star and will soon have the necessary towing winch installed.

Community Relations Handbook.

ERIC Educational Resources Information Center

Literacy Volunteers, Inc., Syracuse, NY.

A handbook for a community relations coordinator for Literacy Volunteers of America, Inc. is presented. An explanation of placement and advance planning is included. Information on flyers, posters, and newsletters; advance preparation of photographs, identifying them, and getting releases; and examples of news releases and steps in preparing them…

Use of Modal Acoustic Emission to Monitor Damage Progression in Carbon Fiber/Epoxy Tows and Implications for Composite Structures

NASA Technical Reports Server (NTRS)

Waller, Jess M.; Saulsberry, Regor L.; Nichols, Charles T.; Wentzel, Daniel J.

2010-01-01

This slide presentation reviews the use of Modal Acoustic Emission to monitor damage progression to carbon fiber/epoxy tows. There is a risk for catastrophic failure of composite overwrapped pressure vessels (COPVs) due to burst-before-leak (BBL) stress rupture (SR) failure of carbon-epoxy (C/Ep) COPVs. A lack of quantitative nondestructive evaluation (NDE) is causing problems in current and future spacecraft designs. It is therefore important to develop and demonstrate critical NDE that can be implemented during stages of the design process since the observed rupture can occur with little of no advanced warning. Therefore a program was required to develop quantitative acoustic emission (AE) procedures specific to C/Ep overwraps, but which also have utility for monitoring damage accumulation in composite structure in general, and to lay the groundwork for establishing critical thresholds for accumulated damage in composite structures, such as COPVs, so that precautionary or preemptive engineering steps can be implemented to minimize of obviate the risk of catastrophic failure. A computed Felicity Ratio (FR) coupled with fast Fourier Transform (FFT) frequency analysis shows promise as an analytical pass/fail criterion. The FR analysis and waveform and FFT analysis are reviewed

Superconducting magnetic sensors for mine detection and classification

NASA Astrophysics Data System (ADS)

Clem, Ted R.; Koch, Roger H.; Keefe, George A.

1995-06-01

Sensors incorporating Superconducting Quantum Interference Devices (SQUIDs) provide the greatest sensitivity for magnetic anomaly detection available with current technology. During the 1980's, the Naval Surface Warfare Center Coastal Systems Station (CSS) developed a superconducting magnetic sensor capable of operation outside of the laboratory environment. This sensor demonstrated rugged, reliable performance even onboard undersea towed platforms. With this sensor, the CSS was able to demonstrate buried mine detection for the US Navy. Subsequently the sensor was incorporated into a multisensor suite onboard an underwater towed vehicle to provide a robust mine hunting capability for the Magnetic and Acoustic Detection of Mines (MADOM) project. This sensor technology utilized niobium superconducting componentry cooled by liquid helium to temperatures on the order of 4 degrees Kelvin (K). In the late 1980's a new class of superconductors was discovered with critical temperatures above the boiling point of liquid nitrogen (77K). This advance has opened up new opportunities, especially for mine reconnaissance and hunting from small unmanned underwater vehicles (UUVs). This paper describes the magnetic sensor detection and classification concept developed for MADOM. In addition, opportunities for UUV operations made possible with high Tc technology and the Navy's current efforts in this area will be addressed.

NASA. Langley Research Center dry powder towpreg system

NASA Technical Reports Server (NTRS)

Baucom, Robert M.; Marchello, Joseph M.

1990-01-01

Dry powder polymer impregnated carbon fiber tows were produced for preform weaving and composite materials molding applications. In the process, fluidized powder is deposited on spread tow bundles and melted on the fibers by radiant heating to adhere the polymer to the fiber. Unit design theory and operating correlations were developed to provide the basis for scale up of the process to commercial operation. Special features of the operation are the pneumatic tow spreader, fluidized bed, resin feeder, and quality control system. Bench scale experiments, at tow speeds up to 50 cm/sec, demonstrated that process variables can be controlled to produce weavable LARC-TPI carbon fiber towpreg. The towpreg made by the dry powder process was formed into unidirectional fiber moldings and was woven and molded into preform material of good quality.

The price of placements in residential and nursing home care: the effects of contracts and competition.

PubMed

Forder, J; Netten, A

2000-10-01

A variety of contract types are used in the placement of elderly people in residential and nursing care homes in the UK. Contracts vary according to how and when providers are paid. Among other things, prices can be made contingent on the total quantity of service to be purchased and on production cost characteristics. They can be determined at the time of placement or in advance. The primary objective of this paper is to assess the impact of contract choices on the price of placements. Regression analysis was conducted on a final sample of 1780 publicly funded placements made in 18 local authorities in the UK over a 6-month period ending in early 1996. Controlling factors included in the price analysis were production cost indicators and those measuring market competitiveness. Choices of both quantity and cost contingent contracts were found to be significantly associated with placement prices. The findings support the hypothesis that contract payment arrangements have different risk, insurance and information properties, and so have implications for the performance of residential care providers.

Simulation based optimization on automated fibre placement process

NASA Astrophysics Data System (ADS)

Lei, Shi

2018-02-01

In this paper, a software simulation (Autodesk TruPlan & TruFiber) based method is proposed to optimize the automate fibre placement (AFP) process. Different types of manufacturability analysis are introduced to predict potential defects. Advanced fibre path generation algorithms are compared with respect to geometrically different parts. Major manufacturing data have been taken into consideration prior to the tool paths generation to achieve high success rate of manufacturing.

The role of interventional radiology in management of benign and malignant gynecologic diseases.

PubMed

Yu, Hyeon; Stavas, Joseph M

2013-10-01

This article focuses on the role of interventional radiology in the therapeutic and diagnostic management of benign and malignant gynecologic conditions. The subspecialty of interventional radiology utilizes minimally invasive advanced image-guided percutaneous techniques in gynecology that include central venous catheter placement, fluid aspiration, drainage catheter placement, tissue biopsy, inferior vena cava filter placement, and pelvic arterial embolization. Central venous catheters, such as ports, peripherally inserted central catheters, and tunneled catheters, are placed for intermediate to long-term intravenous chemotherapy or total parental nutrition or antibiotics. Patients with refractory malignant ascites or pleural effusion from seeding of advanced gynecologic cancers may benefit by percutaneous aspiration of fluid collections or placement of drainage catheters. Postoperative fluid collections including abscess, seroma, or lymphocele are managed by percutaneous drainage catheter insertion. Pelvic, peritoneal, or retroperitoneal masses can be sampled by image-guided percutaneous biopsy or aspiration of fluid to determine a pathologic diagnosis. Certain patients are at risk for deep venous thrombosis with pulmonary embolism and may benefit from an inferior vena cava filter. Patients with uncontrolled postoperative or postpartum bleeding can be effectively managed with emergent transarterial pelvic embolization. Each of the aforementioned interventions with indications, expected benefits, and complications is described including a published literature.

49 CFR 392.63 - Towing or pushing loaded buses.

Code of Federal Regulations, 2014 CFR

2014-10-01

... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS DRIVING OF... passengers aboard for the purpose of towing or pushing any disabled motor vehicle, except in such...

49 CFR 392.63 - Towing or pushing loaded buses.

Code of Federal Regulations, 2012 CFR

2012-10-01

... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS DRIVING OF... passengers aboard for the purpose of towing or pushing any disabled motor vehicle, except in such...

49 CFR 392.63 - Towing or pushing loaded buses.

Code of Federal Regulations, 2013 CFR

2013-10-01

... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS DRIVING OF... passengers aboard for the purpose of towing or pushing any disabled motor vehicle, except in such...

49 CFR 392.63 - Towing or pushing loaded buses.

Code of Federal Regulations, 2011 CFR

2011-10-01

... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS DRIVING OF... passengers aboard for the purpose of towing or pushing any disabled motor vehicle, except in such...

Method for Coating a Tow with an Electrospun Nanofiber

NASA Technical Reports Server (NTRS)

Kohlman, Lee W. (Inventor); Roberts, Gary D. (Inventor)

2015-01-01

Method and apparatus for enhancing the durability as well as the strength and stiffness of prepreg fiber tows of the sort used in composite materials are disclosed. The method involves adhering electrospun fibers onto the surface of such composite materials as filament-wound composite objects and the surface of prepreg fiber tows of the sort that are subsequently used in the production of composite materials of the filament-wound, woven, and braided sorts. The apparatus performs the methods described herein.

Imaging a Hydrate-Related Cold Vent Offshore Vancouver Island From Deep-Towed Multichannel Seismic Data

DTIC Science & Technology

2009-02-20

vent). 2500 2600 2700 Distance (m) 2800 2900 3000 1.791 Figure 11. Southeast-northwest seismic section, showing hydrate cap details from DTI 6. The...line DT16 Line DTI 6 continues as a long transit line extending to the north- west. The 1999 COAMS (Canadian Ocean Acoustic Measurement System) grid...inline IN26 is coincident with DTI 6 (Figure 1). A com- bination of the surface-towed seismic data and the deep-towed DTAGS data is needed to provide

Apparatus for Sizing and Rewinding Graphite Fibers

NASA Technical Reports Server (NTRS)

Wilson, M. L.; Stanfield, C. E.

1986-01-01

Equipment ideally suited for research and development of new sizing solutions. Designed expecially for applying thermoplastic sizing solutions to graphite tow consisting of 3,000 to 12,000 filaments per tow, but accommodates other solutions, filament counts, and materials other than graphite. Closed system containing highly volatile methylene chloride vapors. Also ventilation system directly over resin reservoir. Concept used to apply sizing compounds on fiber tows or yarn-type reinforcement materials used in composite technology. Sizing solutions consist of compounds compatible with thermosets as well as thermoplastics.

History of the TOW Missile System

DTIC Science & Technology

1977-10-01

pp. 1 .5 .4 & 1 .5 .5 . (2 ) L t r , DCG/LCS, I I C O M , t o CG, AMC, 29 Nar 65, s u b j : PEVA FY 65 APE P r o j AXMS 4220.X.32909...TOW). HDF. 3 8 ~ t r , C G , MICOM, t o CG, AMC, 23 J u l 65 , s u b j : PEVA FY 66 APE P r o j MCMS 4290.X.32947 (TOW). HDF. $1.7 m i l l

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baucom, R.M.; Marchello, J.M.

Thermoplastic prepregs of LARC-TPI have been produced in a fluidized bed unit on spread continuous fiber tows. The powders are melted on the fibers by radiant heating to adhere the polymer to the fiber. This process produces tow prepreg uniformly without imposing severe stress on the fibers or requiring long high temperature residence times for the polymer. Unit design theory and operating correlations have been developed to provide the basis for scale up to commercial operation. Special features of the operation are the pneumatic tow spreader, fluidized bed and resin feed systems.

36 CFR 3.12 - May I use a vessel to tow a person for water skiing or other similar activities?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false May I use a vessel to tow a person for water skiing or other similar activities? 3.12 Section 3.12 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.12 May I use a vessel to tow a person for water skiing o...

36 CFR 3.12 - May I use a vessel to tow a person for water skiing or other similar activities?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false May I use a vessel to tow a person for water skiing or other similar activities? 3.12 Section 3.12 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.12 May I use a vessel to tow a person for water skiing o...

Adaption of the Magnetometer Towed Array geophysical system to meet Department of Energy needs for hazardous waste site characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cochran, J.R.; McDonald, J.R.; Russell, R.J.

1995-10-01

This report documents US Department of Energy (DOE)-funded activities that have adapted the US Navy`s Surface Towed Ordnance Locator System (STOLS) to meet DOE needs for a ``... better, faster, safer and cheaper ...`` system for characterizing inactive hazardous waste sites. These activities were undertaken by Sandia National Laboratories (Sandia), the Naval Research Laboratory, Geo-Centers Inc., New Mexico State University and others under the title of the Magnetometer Towed Array (MTA).

Side-branch technique for difficult guidewire placement in coronary bifurcation lesion.

PubMed

He, Xingwei; Gao, Bo; Liu, Yujian; Li, Zhuxi; Zeng, Hesong

2016-01-01

Despite tremendous advances in technology and skills, percutaneous coronary intervention (PCI) of bifurcation lesion (BL) remains a particular challenge for the interventionalist. During bifurcation PCI, safe guidewire placement in the main branch (MB) and the side branch (SB) is the first step for successful procedure. However, in certain cases, the complex pattern of vessel anatomy and the mix of plaque distribution may make target vessel wiring highly challenging. Therefore, specific techniques are required for solving this problem. Hereby, we describe a new use of side-branch technique for difficult guidewire placement in BL. Copyright © 2015 Elsevier Inc. All rights reserved.

A Comparative Analysis of Student Participation in the Advancement Via Individual Determination (AVID) Program and Performance on the Grade 11 Michigan Merit Exam (MME)/Act

ERIC Educational Resources Information Center

Flye, Alesia L.

2017-01-01

The Advancement Via Individual Determination (AVID) curriculum emphasizes writing, collaboration, organization, and reading to strengthen academic skills. High school students enrolled in AVID elective classes receive daily academic support, while enrolled in challenging classes such as Advanced Placement (AP). The purpose of this study was to…

Sled Towing Acutely Decreases Acceleration Sprint Time.

PubMed

Wong, Megan A; Dobbs, Ian J; Watkins, Casey M; Barillas, Saldiam R; Lin, Anne; Archer, David C; Lockie, Robert G; Coburn, Jared W; Brown, Lee E

2017-11-01

Wong, MA, Dobbs, IJ, Watkins, C, Barillas, SR, Lin, A, Archer, DC, Lockie, RG, Coburn, JW, and Brown, LE. Sled towing acutely decreases acceleration sprint time. J Strength Cond Res 31(11): 3046-3051, 2017-Sled towing is a common form of overload training in sports to develop muscular strength for sprinting. This type of training leads to acute and chronic outcomes. Acute training potentially leads to postactivation potentiation (PAP), which is when subsequent muscle performance is enhanced after a preload stimulus. The purpose of this study was to determine differences between rest intervals after sled towing on acute sprint speed. Twenty healthy recreationally trained men (age = 22.3 ± 2.4 years, height = 176.95 ± 5.46 cm, mass = 83.19 ± 11.31 kg) who were currently active in a field sport twice a week for the last 6 months volunteered to participate. A maximal 30-meter (m) baseline (BL) body mass (BM) sprint was performed (with splits at 5, 10, 20, and 30 m) followed by 5 visits where participants sprinted 30 m towing a sled at 30% BM then rested for 2, 4, 6, 8, or 12 minutes. They were instructed to stand still during rest times. After the rest interval, they performed a maximal 30-m post-test BM sprint. Analysis of variance (ANOVA) revealed that post sled tow BM sprint times (4.47 ± 0.21 seconds) were less than BL times (4.55 ± 0.18 seconds) on an individualized rest interval basis. A follow-up 2 × 4 ANOVA showed that this decrease occurred only in the acceleration phase over the first 5 m (BL = 1.13 ± 0.08 seconds vs. Best = 1.08 ± 0.08 seconds), which may be the result of PAP and the complex relationship between fatigue and potentiation relative to the intensity of the sled tow and the rest interval. Therefore, coaches should test their athletes on an individual basis to determine optimal rest time after a 30-m 30% BM sled tow to enhance acute sprint speed.

ARC-1944-AA-6374

NASA Image and Video Library

1944-08-31

Towing installations on P-51 and P-61 airplanes for propeller off tests on the P-51. Rear view of P-61 in towing position preparing for take off at NACA Ames Research Center, Moffett Field, California

M2-F1 in flight during low-speed car tow

NASA Technical Reports Server (NTRS)

1963-01-01

The M2-F1 shown in flight during a low-speed car tow runs across the lakebed. Such tests allowed about two minutes to test the vehicle's handling in flight. NASA Flight Research Center (later redesignated the Dryden Flight Research Center) personnel conducted as many as 8 to 14 ground-tow flights in a single day either to test the vehicle in preparation for air tows or to train pilots to fly the vehicle before they undertook air tows. The wingless, lifting body aircraft design was initially concieved as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Dryden management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. This vehicle needed to be able to tow the M2-F1 on the Rogers Dry Lakebed adjacent to NASA's Flight Research Center (FRC) at a minimum speed of 100 miles per hour. To do that, it had to handle the 400-pound pull of the M2-F1. Walter 'Whitey' Whiteside, who was a retired Air Force maintenance officer working in the FRC's Flight Operations Division, was a dirt-bike rider and hot-rodder. Together with Boyden 'Bud' Bearce in the Procurement and Supply Branch of the FRC, Whitey acquired a Pontiac Catalina convertible with the largest engine available. He took the car to Bill Straup's renowned hot-rod shop near Long Beach for modification. With a special gearbox and racing slicks, the Pontiac could tow the 1,000-pound M2-F1 110 miles per hour in 30 seconds. It proved adequate for the roughly 400 car tows that got the M2-F1 airborne to prove it could fly safely and to train pilots before they were towed behind a C-47 aircraft and released. These initial car-tow tests produced enough flight data about the M2-F1 to proceed with flights behind the C-47 tow plane at greater altitudes. The C-47 took the craft to an altitude of 12,000 where free flights back to Rogers Dry Lake began. Pilot for the first series of flights of the M2-F1 was NASA research pilot Milt Thompson. Typical glide flights with the M2-F1 lasted about two minutes and reached speeds of 110 to l20 mph. A small solid landing rocket, referred to as the 'instant L/D rocket,' was installed in the rear base of the M2-F1. This rocket, which could be ignited by the pilot, provided about 250 pounds of thrust for about 10 seconds. The rocket could be used to extend the flight time near landing if needed. More than 400 ground tows and 77 aircraft tow flights were carried out with the M2-F1. The success of Dryden's M2-F1 program led to NASA's development and construction of two heavyweight lifting bodies based on studies at NASA's Ames and Langley research centers--the M2-F2 and the HL-10, both built by the Northrop Corporation, and the U.S. Air Force's X-24 program, with an X-24A and -B built by Martin. The Lifting Body program also heavily influenced the Space Shuttle program. The M2-F1 program demonstrated the feasibility of the lifting body concept for horizontal landings of atmospheric entry vehicles. It also demonstrated a procurement and management concept for prototype flight test vehicles that produced rapid results at very low cost (approximately $50,000, excluding salaries of government employees assigned to the project).

Advancing beyond AP Courses

ERIC Educational Resources Information Center

Hammond, Bruce G.

2009-01-01

A quiet revolution is picking up steam in the nation's private secondary schools, with broad implications for college admissions and for teaching and learning on both sides of the transition from high school to college. About 50 of the nation's leading college-preparatory schools have opted out of the College Board's Advanced Placement (AP)…

Carded Tow Real-Time Color Assessment: A Spectral Camera-Based System.

PubMed

Furferi, Rocco; Governi, Lapo; Volpe, Yary; Carfagni, Monica

2016-08-31

One of the most important parameters to be controlled during the production of textile yarns obtained by mixing pre-colored fibers, is the color correspondence between the manufactured yarn and a given reference, usually provided by a designer or a customer. Obtaining yarns from raw pre-colored fibers is a complex manufacturing process entailing a number of steps such as laboratory sampling, color recipe corrections, blowing, carding and spinning. Carding process is the one devoted to transform a "fuzzy mass" of tufted fibers into a regular mass of untwisted fibers, named "tow". During this process, unfortunately, the correspondence between the color of the tow and the target one cannot be assured, thus leading to yarns whose color differs from the one used for reference. To solve this issue, the main aim of this work is to provide a system able to perform a spectral camera-based real-time measurement of a carded tow, to assess its color correspondence with a reference carded fabric and, at the same time, to monitor the overall quality of the tow during the carding process. Tested against a number of differently colored carded fabrics, the proposed system proved its effectiveness in reliably assessing color correspondence in real-time.

Freedom Star tows a barge with an SLWT into Port Canaveral for the first time

NASA Technical Reports Server (NTRS)

1998-01-01

Freedom Star, one of NASA's two solid rocket booster recovery ships, tows a barge containing the third Space Shuttle super lightweight external tank (SLWT) into Port Canaveral. This SLWT will be used to launch the orbiter Discovery on mission STS-95 in October. This first-time towing arrangement, part of a cost savings plan by NASA to prudently manage existing resources, began June 12 from the Michoud Assembly Facility in New Orleans where the Shuttle's external tanks are manufactured. The barge will now be transported up the Banana River to the LC-39 turn basin using a conventional tugboat. Previously, NASA relied on an outside contractor to provide external tank towing services at a cost of about $120,000 per trip. The new plan allows NASA's Space Flight Operations contractor, United Space Alliance (USA), to provide the same service directly to NASA using the recovery ships during their downtime between Shuttle launches. Studies show a potential savings of about $50,000 per trip. The cost of the necessary ship modifications should be paid back by the fourteenth tank delivery. The other recovery ship, Liberty Star, has also undergone deck strengthening enhancements and will soon have the necessary towing winch installed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

John J. Gangloff Jr; Shatil Sinha; Suresh G. Advani

The formation and transport of voids in composite materials remains a key research area in composite manufacturing science. Knowledge of how voids, resin, and fiber reinforcement propagate throughout a composite material continuum from green state to cured state during an automated tape layup process is key to minimizing defects induced by void-initiated stress concentrations under applied loads for a wide variety of composite applications. This paper focuses on modeling resin flow in a deforming fiber tow during an automated process of partially impregnated thermoset prepreg composite material tapes. In this work, a tow unit cell based model has been presentedmore » that determines the consolidation and impregnation of a thermoset prepreg tape under an input pressure profile. A parametric study has been performed to characterize the behavior of varying tow speed and compaction forces on the degree of consolidation. Results indicate that increased tow consolidation is achieved with slower tow speeds and higher compaction forces although the relationship is not linear. The overall modeling of this project is motivated to address optimization of the 'green state' composite properties and processing parameters to reduce or eliminate 'cured state' defects, such as porosity and de-lamination. This work is partially funded by the Department of Energy under Award number DE-EE0001367.« less

National automotive sampling system crashworthiness data system 1994-1996

DOT National Transportation Integrated Search

1999-10-01

This report focuses attention on occupants of those passenger vehicles that were towed from : the crash scene. NHTSA's National Automotive Sampling System (NASS)/ Crashworthiness : Data System (CDS) collects detailed information on towed passenger ve...

43 CFR 423.37 - Winter activities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... motor vehicle or snowmobile, except that you may tow sleds designed to be towed behind snowmobiles if... any appropriate means. (b) You must not ice skate, ice fish, or ice sail within 300 yards of dams...

43 CFR 423.37 - Winter activities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... motor vehicle or snowmobile, except that you may tow sleds designed to be towed behind snowmobiles if... any appropriate means. (b) You must not ice skate, ice fish, or ice sail within 300 yards of dams...

ARC-1944-AAL-6372

NASA Image and Video Library

1944-08-31

Towing installations on P-51 and P-61 airplanes for propeller off tests on the P-51 Front view of P-51 & P-61 in towing position preparing for take off at NACA Ames Research Center, Moffett Field, California

ARC-1944-AAL-6371

NASA Image and Video Library

1944-08-31

Towing installations on P-51 and P-61 airplanes for propeller off tests on the P-51 Front view of P-51 & P-61 in towing position preparing for take off at NACA Ames Research Center, Moffett Field, California

ARC-1944-AAL-6373

NASA Image and Video Library

1944-08-31

Towing installations on P-51 airplane for propeller off tests on the P-51 Front view of P-51 in towing position with P-61A preparing for take off at NACA Ames Research Center, Moffett Field, California

TIMSS Advanced 2015 and Advanced Placement Calculus & Physics. A Framework Analysis. Research in Review 2016-1

ERIC Educational Resources Information Center

Lazzaro, Christopher; Jones, Lee; Webb, David C.; Grover, Ryan; Di Giacomo, F. Tony; Marino, Katherine Adele

2016-01-01

This report will determine to what degree the AP Physics 1 and 2 and AP Calculus AB and BC frameworks are aligned with the Trends in International Mathematics and Science Study (TIMSS) Advanced Physics and Mathematics frameworks. This will enable an exploration of any differences in content coverage and levels of complexity, and will set the stage…

Polymer infiltration studies

NASA Technical Reports Server (NTRS)

Marchello, Joseph M.

1994-01-01

During the past three months, significant progress has been made on the preparation of carbon fiber composites using advanced polymer resins. The results are set forth in recent reports and publications, and will be presented at forthcoming national and international meetings. Current and ongoing research activities reported herein include: textile composites from powder-coated towpreg - role of surface coating in braiding; prepregger hot sled operation in making tape from powder coated tow; ribbonizing powder-impregnated towpreg; textile composites from powder-coated towpreg - role of bulk factor in consolidation; powder curtain prepreg process improvements in doctoring of powder; and hot/cold shoe for ATP open-section part warpage control.

Proposed Advance Measures Flood Control Project Hampton Township, Bay County, Michigan. Intensive Archaeological Survey. Volume 1,

DTIC Science & Technology

1987-08-01

S _6RIDGE 559ROAD S99 * Radio ToW~ a (W BC ------ ed itnpiton01. UI PEN ’- EE- .ALn7 I 31 tt ,5 (’I b h a"" ,,.... .- O.CORRIDOR SEGMENT 3 , ,17.- 1A...followed in 1857. Gerardus Vennix and Henry Rooiskers, Hollan- ders, came in 1858 along with Louis Gullette of Mt. Clemens , Michigan, Patrick Bergen...quality chert or agate. Type identity is unknown to Mr. Neering. The cache was found by Paul Schmidt , another local HAS member. Mr. Neering advises me

Optimal sensor placement for deployable antenna module health monitoring in SSPS using genetic algorithm

NASA Astrophysics Data System (ADS)

Yang, Chen; Zhang, Xuepan; Huang, Xiaoqi; Cheng, ZhengAi; Zhang, Xinghua; Hou, Xinbin

2017-11-01

The concept of space solar power satellite (SSPS) is an advanced system for collecting solar energy in space and transmitting it wirelessly to earth. However, due to the long service life, in-orbit damage may occur in the structural system of SSPS. Therefore, sensor placement layouts for structural health monitoring should be firstly considered in this concept. In this paper, based on genetic algorithm, an optimal sensor placement method for deployable antenna module health monitoring in SSPS is proposed. According to the characteristics of the deployable antenna module, the designs of sensor placement are listed. Furthermore, based on effective independence method and effective interval index, a combined fitness function is defined to maximize linear independence in targeted modes while simultaneously avoiding redundant information at nearby positions. In addition, by considering the reliability of sensors located at deployable mechanisms, another fitness function is constituted. Moreover, the solution process of optimal sensor placement by using genetic algorithm is clearly demonstrated. At last, a numerical example about the sensor placement layout in a deployable antenna module of SSPS is presented, which by synthetically considering all the above mentioned performances. All results can illustrate the effectiveness and feasibility of the proposed sensor placement method in SSPS.

LARC powder prepreg system

NASA Technical Reports Server (NTRS)

Baucom, Robert M.; Marchello, Joseph M.

1990-01-01

Thermoplastic prepregs of LARC-TPI have been produced in a fluidized bed unit on spread continuous fiber tows. The powders are melted on the fibers by radiant heating to adhere the polymer to the fiber. This process produces tow prepreg uniformly without imposing severe stress on the fibers or requiring long high temperature residence times for the polymer. Unit design theory and operating correlations have been developed to provide the basis for scale up to commercial operation. Special features of the operation are the pneumatic tow spreader, fluidized bed and resin feed systems.

Rapid Prototyping of Continuous Fiber Reinforced Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Vaidyanathan, R.; Green, C.; Phillips, T.; Cipriani, R.; Yarlagadda, S.; Gillespie, J.; Effinger, M.; Cooper, K. C.; Gordon, Gail (Technical Monitor)

2002-01-01

For ceramics to be used as structural components in high temperature applications, their fracture toughness is improved by embedding continuous ceramic fibers. Ceramic matrix composite (CMC) materials allow increasing the overall operating temperature, raising the temperature safety margins, avoiding the need for cooling, and improving the damping capacity, while reducing the weight at the same time. They also need to be reliable and available in large quantities as well. In this paper, an innovative rapid prototyping technique to fabricate continuous fiber reinforced ceramic matrix composites is described. The process is simple, robust and will be widely applicable to a number of high temperature material systems. This technique was originally developed at the University of Delaware Center for Composite Materials (UD-CCM) for rapid fabrication of polymer matrix composites by a technique called automated tow placement or ATP. The results of mechanical properties and microstructural characterization are presented, together with examples of complex shapes and parts. It is believed that the process will be able to create complex shaped parts at an order of magnitude lower cost than current CVI and PIP processes.

Fabrication of Polyimide-Matrix/Carbon and Boron-Fiber Tape

NASA Technical Reports Server (NTRS)

Belvin, Harry L.; Cano, Roberto J.; Treasure, Monte; Shahood, Thomas W.

2007-01-01

The term HYCARB denotes a hybrid composite of polyimide matrices reinforced with carbon and boron fibers. HYCARB and an improved process for fabricating dry HYCARB tapes have been invented in a continuing effort to develop lightweight, strong composite materials for aerospace vehicles. Like other composite tapes in this line of development, HYCARB tapes are intended to be used to build up laminated structures having possibly complex shapes by means of automated tow placement (ATP) - a process in which a computer-controlled multiaxis machine lays down prepreg tape or tows. The special significance of the present process for making dry HYCARB for ATP is that it contributes to the reduction of the overall cost of manufacturing boron-reinforced composite-material structures while making it possible to realize increased compression strengths. The present process for making HYCARB tapes incorporates a "wet to dry" process developed previously at Langley Research Center. In the "wet to dry" process, a flattened bundle of carbon fiber tows, pulled along a continuous production line between pairs of rollers, is impregnated with a solution of a poly(amide acid) in N-methyl-2-pyrrolidinone (NMP), then most of the NMP is removed by evaporation in hot air. In the present case, the polyamide acid is, more specifically, that of LaRC. IAX (or equivalent) thermoplastic polyimide, and the fibers are, more specifically, Manganite IM7 (or equivalent) polyacrylonitrile- based carbon filaments that have a diameter of 5.2 m and are supplied in 12,000-filament tows. The present process stands in contrast to a prior process in which HYCARB tape was made by pressing boron fibers into the face of a wet carbon-fiber/ poly(amide acid) prepreg tape . that is, a prepreg tape from which the NMP solvent had not been removed. In the present process, one or more layer(s) of side-by-side boron fibers are pressed between dry prepreg tapes that have been prepared by the aforementioned gwet to dry h process. The multilayer tape is then heated to imidize the matrix material and remove most of the remaining solvent, and is pressed to consolidate the multiple layers into a dense tape. For tests, specimens of HYCARB tapes and laminated composite panels made from HYCARB tape were prepared as follows: HYCARB tapes were fabricated as described above. Each panel was made by laying down ten layers of tape, containing, variously, one, two, or three boron-fiber plies and the remainder carbon- fiber-only plies (see figure). Each panel was made by laying down ten layers of tape. Each panel was then cured by heating to a temperature of 225 C for 15 minutes, then pressing at 200 psi (A1.4 MPa) while heating to 371 C, holding at 371 C for 1 hour, then continuing to hold pressure during cooling. Control specimens that were otherwise identical except that they did not contain boron fibers also were prepared. In room-temperature flexural tests, the HYCARB specimens performed comparably to the control specimens; in room-temperature, open-hole compression tests, the HYCARB specimens performed slightly better, by amounts that increased with boron content.

20. Photocopy of photograph (original in the Langley Research Center ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. Photocopy of photograph (original in the Langley Research Center Archives, Hampton, VA AERIAL VIEW OF THE SEAPLANE TOWING CHANNEL STRUCTURE. - NASA Langley Research Center, Seaplane Towing Channel, 108 Andrews Street, Hampton, Hampton, VA

Integral Textile Structure for 3-D CMC Turbine Airfoils

NASA Technical Reports Server (NTRS)

Marshall, David B. (Inventor); Cox, Brian N. (Inventor); Sudre, Olivier H. (Inventor)

2017-01-01

An integral textile structure for 3-D CMC turbine airfoils includes top and bottom walls made from an angle-interlock weave, each of the walls comprising warp and weft fiber tows. The top and bottom walls are merged on a first side parallel to the warp fiber tows into a single wall along a portion of their widths, with the weft fiber tows making up the single wall interlocked through the wall's thickness such that delamination of the wall is inhibited. The single wall suitably forms the trailing edge of an airfoil; the top and bottom walls are preferably joined along a second side opposite the first side and parallel to the radial fiber tows by a continuously curved section in which the weave structure remains continuous with the weave structure in the top and bottom walls, the continuously curved section being the leading edge of the airfoil.

Burst Testing of Triaxial Braided Composite Tubes

NASA Technical Reports Server (NTRS)

Salem, J. A.; Bail, J. L.; Wilmoth, N. G.; Ghosn, L. J.; Kohlman, L. W.; Roberts, G. D.; Martin, R. E.

2014-01-01

Applications using triaxial braided composites are limited by the materials transverse strength which is determined by the delamination capacity of unconstrained, free-edge tows. However, structural applications such as cylindrical tubes can be designed to minimize free edge effects and thus the strength with and without edge stresses is relevant to the design process. The transverse strength of triaxial braided composites without edge effects was determined by internally pressurizing tubes. In the absence of edge effects, the axial and transverse strength were comparable. In addition, notched specimens, which minimize the effect of unconstrained tow ends, were tested in a variety of geometries. Although the commonly tested notch geometries exhibited similar axial and transverse net section failure strength, significant dependence on notch configuration was observed. In the absence of unconstrained tows, failure ensues as a result of bias tow rotation, splitting, and fracture at cross-over regions.

46 CFR 45.197 - Operational plan requirements for the Muskegon route.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... (b) A list of mooring and docking facilities (with phone numbers) in St. Joseph, Holland, Grand Haven, and Muskegon, that can accommodate the tow. (c) A list of towing firms (with phone numbers) that have...

46 CFR 45.197 - Operational plan requirements for the Muskegon route.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... (b) A list of mooring and docking facilities (with phone numbers) in St. Joseph, Holland, Grand Haven, and Muskegon, that can accommodate the tow. (c) A list of towing firms (with phone numbers) that have...

46 CFR 45.197 - Operational plan requirements for the Muskegon route.

Code of Federal Regulations, 2012 CFR

2012-10-01

.... (b) A list of mooring and docking facilities (with phone numbers) in St. Joseph, Holland, Grand Haven, and Muskegon, that can accommodate the tow. (c) A list of towing firms (with phone numbers) that have...

46 CFR 45.197 - Operational plan requirements for the Muskegon route.

Code of Federal Regulations, 2014 CFR

2014-10-01

.... (b) A list of mooring and docking facilities (with phone numbers) in St. Joseph, Holland, Grand Haven, and Muskegon, that can accommodate the tow. (c) A list of towing firms (with phone numbers) that have...

46 CFR 45.197 - Operational plan requirements for the Muskegon route.

Code of Federal Regulations, 2013 CFR

2013-10-01

.... (b) A list of mooring and docking facilities (with phone numbers) in St. Joseph, Holland, Grand Haven, and Muskegon, that can accommodate the tow. (c) A list of towing firms (with phone numbers) that have...

On the Reading of Poetry in Relationship to Testing.

ERIC Educational Resources Information Center

Borden, Arthur R., Jr.

1967-01-01

Experience in evaluating responses to poetry in the Advanced Placement Examination can offer guidelines for the effective testing of students on poetry without reducing their interest in the art. For advanced secondary or first-year college students, teachers should avoid approaches and tests that are concerned with (1) extraneous biographical,…

Tension fracture of laminates for transport fuselage. Part 2: Large notches

NASA Technical Reports Server (NTRS)

Walker, Tom H.; Ilcewicz, Larry B.; Polland, D. R.; Poe, C. C., Jr.

1993-01-01

Tests were conducted on over 200 center-crack specimens to evaluate: (a) the tension-fracture performance of candidate materials and laminates for commercial fuselage applications; and (b) the accuracy of several failure criteria in predicting response. Crack lengths of up to 12 inches were considered. Other variables included fiber/matrix combination, layup, lamination manufacturing process, and intraply hybridization. Laminates fabricated using the automated tow-placement process provided significantly higher tension-fracture strengths than nominally identical tape laminates. This confirmed earlier findings for other layups, and possibly relates to a reduced stress concentration resulting from a larger scale of repeatable material inhomogeneity in the tow-placed laminates. Changes in material and layup result in a trade-off between small-notch and large-notch strengths. Toughened resins and 0 deg-dominate layups result in higher small-notch strengths but lower large-notch strengths than brittle resins, 90 deg and 45 deg dominated layups, and intraply S2-glass hybrid material forms. Test results indicate that strength-prediction methods that allow for a reduced order singularity of the crack-tip stress field are more successful at predicting failure over a range of notch sizes than those relying on the classical square-root singularity. The order of singularity required to accurately predict large-notch strength from small-notch data was affected by both material and layup. Measured crack-tip strain distributions were generally higher than those predicted using classical methods. Traditional methods of correcting for finite specimen width were found to be lacking, confirming earlier findings with other specimen geometries. Fracture tests of two stiffened panels, identical except for differing materials, with severed central stiffeners resulted in nearly identical damage progression and failure sequences. Strain-softening laws implemented within finite element models appear attractive to account for load redistribution in configured structure due to damage-induced crack tip softening

18. Photocopy of photograph (original in the Langley Research Center ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

18. Photocopy of photograph (original in the Langley Research Center Archives, Hampton, VA LaRC) (LAL 5169) AERIAL VIEW OF THE SEAPLANE TOWING CHANNEL STRUCTURE. - NASA Langley Research Center, Seaplane Towing Channel, 108 Andrews Street, Hampton, Hampton, VA

19. Photocopy of photograph (original in the Langley Research Center ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

19. Photocopy of photograph (original in the Langley Research Center Archives, Hampton, VA LaRC) (L81-05967) AERIAL VIEW OF THE SEAPLANE TOWING CHANNEL STRUCTURE. - NASA Langley Research Center, Seaplane Towing Channel, 108 Andrews Street, Hampton, Hampton, VA

Report to Congress on the "Review of Federal and State Laws Regarding Vehicle Towing".

DOT National Transportation Integrated Search

2007-05-11

This report summarizes current federal and state law and jurisprudence regarding nonconsensual motor vehicle towing, and also provides an overview of information obtained from major stakeholder groups regarding this topic. Major issues related to non...

Comparison of Curvilinear Stiffeners and Tow Steered Composites for Aeroelastic Tailoring of Transports

NASA Technical Reports Server (NTRS)

Stanford, Bret K.; Jutte, Christine V.

2016-01-01

A series of aeroelastic optimization problems are solved on a high aspect ratio wingbox of the Common Research Model, in an effort to minimize structural mass under coupled stress, buckling, and flutter constraints. Two technologies are of particular interest: tow steered composite laminate skins and curvilinear stiffeners. Both methods are found to afford feasible reductions in mass over their non-curvilinear structural counterparts, through both distinct and shared mechanisms for passively controlling aeroelastic performance. Some degree of diminishing returns are seen when curvilinear stiffeners and curvilinear fiber tow paths are used simultaneously.

Fatigue Investigation of the E-2B/C Nose Landing Gear

DTIC Science & Technology

1975-12-31

Specimen - Outer Cylinder and Caster Barrel 9 3 E-2B NLG Test Specimen - Drag Brace 10 4 E-2B NLG Drag Brace Attachment Lugs Modification . . 11 5...Attachment Lug Fracture Surface . . 23 ■■■■ ? 16 Tow Link Modification 30 17 Tow Link #2 Failur 31 18 Tow Link #2 Fracture Face 32 19...34-" ’’- .-.„.,.,„...^ ,.., M1| lf^^~i*>-^^-^^ "u- II li ’ 7«™.™»«*" ■ NADC-75369-30 Bach «hock «true assembly consist« of the «xle- caster barrel, outer cylinder

Combining LaRC-TPI powder with carbon fiber by electrostatic fluidized bed coating

NASA Technical Reports Server (NTRS)

Varughese, Babu; Muzzy, John; Baucom, Robert M.

1989-01-01

Thermoplastic polyimide prepreg tow is produced rapidly and efficiently by applying the LaRC-TPI matrix as an electrostatically charged and fluidized powder to electrically grounded and spread carbon fiber tow. The powder is melted after coating to insure adhesion to the fibers and to reduce tow friction. Excellent wetout in towpreg samples is obtained resulting in very flexible prepregs. Processing conditions of this towpreg produced with LaRC-TPI powders from Rogers Corp. and Mitsui Toatsu Chemicals are described. Mechanical properties of the towpreg and unidirectional laminates are presented in detail.

Stress induced by hooking, net towing, elevated sea water temperature and air in sablefish: Lack of concordance between mortality and physiological measures of stress

USGS Publications Warehouse

Davis, M.W.; Olla, B.L.; Schreck, C.B.

2001-01-01

In a series of laboratory studies designed to simulate bycatch processes, sablefish Anoplopoma fimbria were either hooked for up to 24 h or towed in a net for 4 h and then subjected to an abrupt transfer to elevated sea water temperature and air. Mortality did not result from hooking or net towing followed by exposure to air, but increased for both capture methods as fish were exposed to elevated temperatures, reflecting the magnifying effect of elevated temperature on mortality. Hooking and exposure to air resulted in increased plasma cortisol and lactate concentrations, while the combination of hooking and exposure to elevated temperature and air resulted in increased lactate and potassium concentrations. In fish that were towed in a net and exposed to air, cortisol, lactate, potassium and sodium concentrations increased, but when subjected to elevated temperature and air, no further increases occurred above the concentrations induced by net towing and air, suggesting a possible maximum of the physiological stress response. The results suggest that caution should be exercised when using physiological measures to quantify stress induced by capture and exposure to elevated temperature and air, that ultimately result in mortality, since the connections between physiological stress and mortality in bycatch processes remain to be fully understood.

Flipped Classrooms for Advanced Science Courses

NASA Astrophysics Data System (ADS)

Tomory, Annette; Watson, Sunnie Lee

2015-12-01

This article explains how issues regarding dual credit and Advanced Placement high school science courses could be mitigated via a flipped classroom instructional model. The need for advanced high school courses will be examined initially, followed by an analysis of advanced science courses and the reform they are experiencing. Finally, it will conclude with an explanation of flipped classes as well as how they may be a solution to the reform challenges teachers are experiencing as they seek to incorporate more inquiry-based activities.

Deghosting based on the transmission matrix method

NASA Astrophysics Data System (ADS)

Wang, Benfeng; Wu, Ru-Shan; Chen, Xiaohong

2017-12-01

As the developments of seismic exploration and subsequent seismic exploitation advance, marine acquisition systems with towed streamers become an important seismic data acquisition method. But the existing air-water reflective interface can generate surface related multiples, including ghosts, which can affect the accuracy and performance of the following seismic data processing algorithms. Thus, we derive a deghosting method from a new perspective, i.e. using the transmission matrix (T-matrix) method instead of inverse scattering series. The T-matrix-based deghosting algorithm includes all scattering effects and is convergent absolutely. Initially, the effectiveness of the proposed method is demonstrated using synthetic data obtained from a designed layered model, and its noise-resistant property is also illustrated using noisy synthetic data contaminated by random noise. Numerical examples on complicated data from the open SMAART Pluto model and field marine data further demonstrate the validity and flexibility of the proposed method. After deghosting, low frequency components are recovered reasonably and the fake high frequency components are attenuated, and the recovered low frequency components will be useful for the subsequent full waveform inversion. The proposed deghosting method is currently suitable for two-dimensional towed streamer cases with accurate constant depth information and its extension into variable-depth streamers in three-dimensional cases will be studied in the future.

First magnetic resonance imaging-guided aortic stenting and cava filter placement using a polyetheretherketone-based magnetic resonance imaging-compatible guidewire in swine: proof of concept.

PubMed

Kos, Sebastian; Huegli, Rolf; Hofmann, Eugen; Quick, Harald H; Kuehl, Hilmar; Aker, Stephanie; Kaiser, Gernot M; Borm, Paul J A; Jacob, Augustinus L; Bilecen, Deniz

2009-05-01

The purpose of this study was to demonstrate feasibility of percutaneous transluminal aortic stenting and cava filter placement under magnetic resonance imaging (MRI) guidance exclusively using a polyetheretherketone (PEEK)-based MRI-compatible guidewire. Percutaneous transluminal aortic stenting and cava filter placement were performed in 3 domestic swine. Procedures were performed under MRI-guidance in an open-bore 1.5-T scanner. The applied 0.035-inch guidewire has a PEEK core reinforced by fibres, floppy tip, hydrophilic coating, and paramagnetic markings for passive visualization. Through an 11F sheath, the guidewire was advanced into the abdominal (swine 1) or thoracic aorta (swine 2), and the stents were deployed. The guidewire was advanced into the inferior vena cava (swine 3), and the cava filter was deployed. Postmortem autopsy was performed. Procedural success, guidewire visibility, pushability, and stent support were qualitatively assessed by consensus. Procedure times were documented. Guidewire guidance into the abdominal and thoracic aortas and the inferior vena cava was successful. Stent deployments were successful in the abdominal (swine 1) and thoracic (swine 2) segments of the descending aorta. Cava filter positioning and deployment was successful. Autopsy documented good stent and filter positioning. Guidewire visibility through applied markers was rated acceptable for aortic stenting and good for venous filter placement. Steerability, pushability, and device support were good. The PEEK-based guidewire allows either percutaneous MRI-guided aortic stenting in the thoracic and abdominal segments of the descending aorta and filter placement in the inferior vena cava with acceptable to good device visibility and offers good steerability, pushability, and device support.

First Magnetic Resonance Imaging-Guided Aortic Stenting and Cava Filter Placement Using a Polyetheretherketone-Based Magnetic Resonance Imaging-Compatible Guidewire in Swine: Proof of Concept

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kos, Sebastian, E-mail: skos@gmx.d; Huegli, Rolf; Hofmann, Eugen

The purpose of this study was to demonstrate feasibility of percutaneous transluminal aortic stenting and cava filter placement under magnetic resonance imaging (MRI) guidance exclusively using a polyetheretherketone (PEEK)-based MRI-compatible guidewire. Percutaneous transluminal aortic stenting and cava filter placement were performed in 3 domestic swine. Procedures were performed under MRI-guidance in an open-bore 1.5-T scanner. The applied 0.035-inch guidewire has a PEEK core reinforced by fibres, floppy tip, hydrophilic coating, and paramagnetic markings for passive visualization. Through an 11F sheath, the guidewire was advanced into the abdominal (swine 1) or thoracic aorta (swine 2), and the stents were deployed. Themore » guidewire was advanced into the inferior vena cava (swine 3), and the cava filter was deployed. Postmortem autopsy was performed. Procedural success, guidewire visibility, pushability, and stent support were qualitatively assessed by consensus. Procedure times were documented. Guidewire guidance into the abdominal and thoracic aortas and the inferior vena cava was successful. Stent deployments were successful in the abdominal (swine 1) and thoracic (swine 2) segments of the descending aorta. Cava filter positioning and deployment was successful. Autopsy documented good stent and filter positioning. Guidewire visibility through applied markers was rated acceptable for aortic stenting and good for venous filter placement. Steerability, pushability, and device support were good. The PEEK-based guidewire allows either percutaneous MRI-guided aortic stenting in the thoracic and abdominal segments of the descending aorta and filter placement in the inferior vena cava with acceptable to good device visibility and offers good steerability, pushability, and device support.« less

Three-finger tracheal palpation to guide endotracheal tube depth in children.

PubMed

Gamble, Jonathan J; McKay, William P; Wang, Andrew F; Yip, Kinsha A; O'Brien, Jennifer M; Plewes, Christopher E

2014-10-01

Accurate endotracheal tube (ETT) depth is critical, especially in children. The current tools used to guide appropriate ETT depth have significant limitations. To evaluate the utility of tracheal palpation in the neck to guide appropriate ETT placement in children. A prospective observational study with a convenience sample of 50 children was conducted. During intubation, an investigator palpated the trachea with three fingertips side-by-side extending upward from the suprasternal notch. The anesthesiologist advanced the ETT slowly until palpated at the sternal notch. The investigator stated ETT palpation certainty as 'strongly felt', 'weakly felt', or 'not felt.' Final ETT position was determined by bronchoscopy and categorized as 'ETT too shallow' (tip in proximal ¼ of trachea), 'ETT too deep' (tip in distal ¼ of trachea), or 'ETT placement satisfactory' (between those extremes). Thirty boys and 20 girls undergoing dental surgery with nasal intubation were recruited (median age 4.4 years; range 2.0-10.8). The ETT (all ≥4 mm ID) was palpable at the sternal notch in all patients: 46 of 50 strongly palpable and 4 of 50 weakly palpable. The experimental methods led to satisfactory ETT placement in 49 of 50 patients, too deep in 1 of 50 patients. Compared with the Pediatrics Advanced Life Support (PALS) predictive formula, satisfactory placement would have been 41 of 50 patients (P < 0.008). Number needed to treat is 6.3 for improvement over the PALS method. The use of tracheal palpation to guide ETT placement has excellent clinical performance and better guides appropriate ETT depth than the PALS formula in our study population. © 2014 John Wiley & Sons Ltd.

77 FR 31631 - Towing Safety Advisory Committee; Vacancies

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-29

... the Secretary of Homeland Security on matters relating to shallow-draft inland and coastal waterway.... 111-281). The Committee advises the Secretary of Homeland Security on matters relating to shallow... towing industry, marine transportation, or business operations associated with shallow-draft inland and...

18. VIEW OF BALES OF CEDAR TOW (CEDAR SHAVING WITH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

18. VIEW OF BALES OF CEDAR TOW (CEDAR SHAVING WITH SAWDUST TUMBLED OUT) SOLD FOR GARDEN AND ANIMAL BEDDING, AND OTHER AGRICULTURAL USES; TUMBLER IS CYLINDRICAL MACHINE TO LEFT - Lester Shingle Mill, 1602 North Eighteenth Street, Sweet Home, Linn County, OR

Exploiting Electric and Magnetic Fields for Underwater Characterization

DTIC Science & Technology

2011-03-01

geophysical surveys are primarily limited to passive magnetic systems towed from a surface vessel. These systems utilize fluxgate , Overhauser, or atomic... magnetometer sensors, often deployed in arrays towed from the stern of small to moderate-size vessels. Active source electromagnetic methods have been

Lake Michigan: Nearshore Variability

EPA Science Inventory

We conducted a high-resolution survey in the nearshore of Lake Michigan at a 20 meter contour using towed electronic instrumentation. The nearly 1200 km survey was conducted Sep 8-15, 2010. We also conducted six cross-contour tows. Along the survey tracks we sampled fixed stat...

Enhancements of Tow-Steering Design Techniques: Design of Rectangular Panel Under Combined Loads

NASA Technical Reports Server (NTRS)

Tatting, Brian F.; Setoodeh, Shahriar; Gurdal, Zafer

2005-01-01

An extension to existing design tools that utilize tow-steering is presented which is used to investigate the use of elastic tailoring for a flat panel with a central hole under combined loads of compression and shear. The elastic tailoring is characterized by tow-steering within individual lamina as well as a novel approach based on selective reinforcement, which attempts to minimize compliance through the use of Cellular Automata design concepts. The selective reinforcement designs lack any consideration of manufacturing constraints, so a new tow-steered path definition was developed to translate the prototype selective reinforcement designs into manufacturable plies. The minimum weight design of a flat panel under combined loading was based on a model provided by NASA-Langley personnel and analyzed by STAGS within the OLGA design environment. Baseline designs using traditional straight fiber plies were generated, as well as tow-steered designs which incorporated parallel, tow-drop, and overlap plies within the laminate. These results indicated that the overlap method provided the best improvement with regards to weight and performance as compared to traditional constant stiffness monocoque panels, though the laminates did not measure up to similar designs from the literature using sandwich and isogrid constructions. Further design studies were conducted using various numbers of the selective reinforcement plies at the core and outer surface of the laminate. None of these configurations exhibited notable advantages with regard to weight or buckling performance. This was due to the fact that the minimization of the compliance tended to direct the major stresses toward the center of the panel, which decreased the ability of the structure to withstand loads leading to instability.

CT-Guided Placement of a Drainage Catheter Within a Pelvic Abscess Using a Transsacral Approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iguchi, Toshihiro; Asami, Shinya; Kubo, Shinichiro

2007-11-15

A 66-year-old man underwent CT-guided drainage catheter placement within a pelvic abscess with a diameter of 46 mm. We performed the drainage by a transsacral approach because it was considered the safest and most feasible approach. An 8G bone marrow biopsy needle was used to penetrate the sacrum to create a path for subsequent drainage catheter insertion. After withdrawal of the biopsy needle, a 6 Fr catheter was advanced into the abscess cavity through the path using the Seldinger technique. Except for bearable pain, no procedure-related complications occurred. Twenty-nine days after the placement, the catheter was withdrawn safely and themore » abscess cavity had shrunk remarkably.« less

Academic Success of At-Risk African American Male Students Who Receive Culturally Relevant Teaching, College Readiness Preparation, and Mentorship

ERIC Educational Resources Information Center

Taylor, Timothy L.

2016-01-01

This quantitative study analyzed archival data to determine whether a significant difference existed in the reading comprehension scores and student success (enrollment in honors and or advanced placement classes and college after graduation) of at-risk African American male students who received Advancement via Individual Determination/African…

Assessing Advanced High School and Undergraduate Students' Thinking Skills: The Chemistry--From the Nanoscale to Microelectronics Module

ERIC Educational Resources Information Center

Dori, Yehudit Judy; Dangur, Vered; Avargil, Shirly; Peskin, Uri

2014-01-01

Chemistry students in Israel have two options for studying chemistry: basic or honors (advanced placement). For instruction in high school honors chemistry courses, we developed a module focusing on abstract topics in quantum mechanics: Chemistry--From the Nanoscale to Microelectronics. The module adopts a visual-conceptual approach, which…

The Employment Retention and Advancement Project. Results from the Texas ERA Site

ERIC Educational Resources Information Center

Martinson, Karin; Hendra, Richard

2006-01-01

This report presents an assessment of the implementation and the two-year impacts of a program in Texas that aimed to promote job placement, employment retention, and advancement among applicants and recipients to the Temporary Assistance for Needy Families (TANF) program. The program in Texas is part of the Employment Retention and Advancement…

What about Me?: Individual Self-Assessment by Skill and Level of Language Instruction

ERIC Educational Resources Information Center

Brantmeier, Cindy; Vanderplank, Robert; Strube, Michael

2012-01-01

In an investigation with advanced language learners, Brantmeier [Brantmeier, C., 2006. "Advanced L2 learners and reading placement: self-assessment, computer based testing, and subsequent performance." "System" 34 (1), 15-35.] reports that self-assessment (SA) of second language (L2) reading ability, when measured with self-rated scales, is not an…

Advanced L2 Learners and Reading Placement: Self-Assessment, CBT, and Subsequent Performance

ERIC Educational Resources Information Center

Brantmeier, Cindy

2006-01-01

There is a dearth of research involving advanced second language (L2) learners in the USA [Brantmeier, C., 2001. Second language reading research on passage content and gender: challenges for the intermediate level curriculum, Foreign Language Annals 34, 325-333; Young, D.J., 2003. Workshop on overcoming anxiety in the foreign language classroom.…

Evaluation of Composite-Hull Ships Operating in Arctic Ice

DTIC Science & Technology

2016-06-01

controller. During the time of thesis submission, public works closed the NPS tow tank spaces for environmental characterization of asbestos , as shown...environmental characterization of asbestos shut down the Halligan Hall tow tank spaces. This prevented the researcher to fully assemble the wave generating

Tow plows could help Michigan save time and money on winter maintenance : research spotlight.

DOT National Transportation Integrated Search

2016-11-01

As winter maintenance costs rise, MDOT is looking into innovative approaches to increase snow removal efficiency. As part of this effort, the department recently estimated the costs and benefits of incorporating tow plows into its equipment fleet. Re...

76 FR 49975 - Inspection of Towing Vessels

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-11

... Coast Guard relies on third parties are when the American Bureau of Shipping (ABS) conducts load line... History B. Regulatory History C. American Bureau of Shipping Group (ABSG) Consulting Uninspected Towing... CONTACT. II. Abbreviations ABS American Bureau of Shipping ABSG American Bureau of Shipping Group ABYC...

Evaluation of the Viking-Cives towplow for winter maintenance.

DOT National Transportation Integrated Search

2014-01-01

To maximize efficiency while minimizing costs within ODOTs winter maintenance budget, ODOT is : evaluating new methods of snow and ice removal. One method is the use of the Viking-Cives TowPlow. The : TowPlow is pulled behind a tandem axle truck a...

21. Photocopy of photograph (original in the Langley Research Center ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. Photocopy of photograph (original in the Langley Research Center Archives, Hampton, VA LaRC) (L84-154) INTERIOR VIEW OF THE SEAPLANE TOWING CHANNEL WITH TANK FULLY DRAINED. - NASA Langley Research Center, Seaplane Towing Channel, 108 Andrews Street, Hampton, Hampton, VA

46 CFR 11.465 - Requirements for endorsements as mate (pilot) of towing vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... demonstration of skills. (3) Your license or MMC does not need to include a towing endorsement if you hold a TOAR or a course completion certificate. (e) If you hold any endorsement as a master of steam or motor...

High-resolution resistivity imaging of marine gas hydrate structures by combined inversion of CSEM towed and ocean-bottom receiver data

NASA Astrophysics Data System (ADS)

Attias, Eric; Weitemeyer, Karen; Hölz, Sebastian; Naif, Samer; Minshull, Tim A.; Best, Angus I.; Haroon, Amir; Jegen-Kulcsar, Marion; Berndt, Christian

2018-06-01

We present high-resolution resistivity imaging of gas hydrate pipe-like structures, as derived from marine controlled-source electromagnetic (CSEM) inversions that combine towed and ocean-bottom electric field receiver data, acquired from the Nyegga region, offshore Norway. Two-dimensional CSEM inversions applied to the towed receiver data detected four new prominent vertical resistive features that are likely gas hydrate structures, located in proximity to a major gas hydrate pipe-like structure, known as the CNE03 pockmark. The resistivity model resulting from the CSEM data inversion resolved the CNE03 hydrate structure in high resolution, as inferred by comparison to seismically constrained inversions. Our results indicate that shallow gas hydrate vertical features can be delineated effectively by inverting both ocean-bottom and towed receiver CSEM data simultaneously. The approach applied here can be utilised to map and monitor seafloor mineralisation, freshwater reservoirs, CO2 sequestration sites and near-surface geothermal systems.

Finite Element Model for Failure Study of Two-Dimensional Triaxially Braided Composite

NASA Technical Reports Server (NTRS)

Li, Xuetao; Binienda, Wieslaw K.; Goldberg, Robert K.

2010-01-01

A new three-dimensional finite element model of two-dimensional triaxially braided composites is presented in this paper. This meso-scale modeling technique is used to examine and predict the deformation and damage observed in tests of straight sided specimens. A unit cell based approach is used to take into account the braiding architecture as well as the mechanical properties of the fiber tows, the matrix and the fiber tow-matrix interface. A 0 deg / plus or minus 60 deg. braiding configuration has been investigated by conducting static finite element analyses. Failure initiation and progressive degradation has been simulated in the fiber tows by use of the Hashin failure criteria and a damage evolution law. The fiber tow-matrix interface was modeled by using a cohesive zone approach to capture any fiber-matrix debonding. By comparing the analytical results to those obtained experimentally, the applicability of the developed model was assessed and the failure process was investigated.

Comparison of Point Placement by Veterinary Professionals with Different Levels of Acupuncture Training in a Canine Cadaver Model.

PubMed

Yang, Toni; Shmalberg, Justin; Hochman, Lindsay; Miscioscia, Erin; Brumby, Meghan; McKenna, Kelsey; Roth, Amber

2017-10-01

Veterinary acupuncture is becoming increasingly implemented for various disease processes, with growing numbers of veterinarians pursuing advanced training to meet the rising demand for this relatively new intervention. Accurate acupoint placement remains challenging, with individual practitioners relying on varying methods of point identification, often compounded by the transpositional nature of points for companion animals. The aim of this study was to assess for differences in acupuncture needle placement of select points between veterinary professionals with three different levels of acupuncture training in an academic teaching environment. Seven participants placed a total of six acupoints on a canine cadaver. Digital radiography was used to document each participant's point placement. Each participant's point location was then compared to a control "correct" point, and the distance between the two points was measured. A significant difference in placement accuracy was identified between the participants when grouped by training level (p = 0.03). These results indicate that veterinary patients receiving acupuncture treatment from veterinarians with different levels of training may subsequently experience varying effects, although further studies are warranted on more specific acupoint description as well as the clinical implications of needle placement accuracy. Copyright © 2017. Published by Elsevier B.V.

Space Shuttle Projects

NASA Image and Video Library

1982-04-01

The towing ship, Liberty, towed a recovered solid rocket booster (SRB) for the STS-3 mission to Port Canaveral, Florida. The recovered SRB would be inspected and refurbished for reuse. The Shuttle's SRB's and solid rocket motors (SRM's) are the largest ever built and the first designed for refurbishment and reuse. Standing nearly 150-feet high, the twin boosters provide the majority of thrust for the first two minutes of flight, about 5.8 million pounds. The requirement for reusability dictated durable materials and construction to preclude corrosion of the hardware exposed to the harsh seawater environment. The SRB contains a complete recovery subsystem that includes parachutes, beacons, lights, and tow fixture.

Space Shuttle Projects

NASA Image and Video Library

1982-11-01

The towing ship, Liberty, towed a recovered solid rocket booster (SRB) for the STS-5 mission to Port Canaveral, Florida. The recovered SRB would be inspected and refurbished for reuse. The Shuttle's SRB's and solid rocket motors (SRM's) are the largest ever built and the first designed for refurbishment and reuse. Standing nearly 150-feet high, the twin boosters provide the majority of thrust for the first two minutes of flight, about 5.8 million pounds. The requirement for reusability dictated durable materials and construction to preclude corrosion of the hardware exposed to the harsh seawater environment. The SRB contains a complete recovery subsystem that includes parachutes, beacons, lights, and tow fixture.

Process for application of powder particles to filamentary materials

NASA Technical Reports Server (NTRS)

Baucom, Robert M. (Inventor); Snoha, John J. (Inventor); Marchello, Joseph M. (Inventor)

1991-01-01

This invention is a process for the uniform application of polymer powder particles to a filamentary material in a continuous manner to form a uniform composite prepreg material. A tow of the filamentary material is fed under carefully controlled tension into a spreading unit, where it is spread pneumatically into an even band. The spread filamentary tow is then coated with polymer particles from a fluidized bed, after which the coated filamentary tow is fused before take-up on a package for subsequent utilization. This process produces a composite prepreg uniformly without imposing severe stress on the filamentary material, and without requiring long, high temperature residence times for the polymer.

Drag Characteristics of Several Towed Decelerator Models at Mach 3

NASA Technical Reports Server (NTRS)

Miserentino, Robert; Bohon, Herman L.

1970-01-01

An investigation has been made to determine the possibility of using toroid-membrane and wide-angle conical shapes as towed decelerators. Parameter variations were investigated which might render toroid-membrane models and wide-angle- cone models stable without loss of the high drag coefficients obtainable with sting-mounted models. The parameters varied included location of center of gravity, location of the pivot between the towline and the model, and configuration modifications of the aft end as the addition of a corner radius and the addition of a skirt. The toroid membrane can be made into a stable towed decelerator with a suitable configuration modification of the aft end.

Calculation of the Lateral Stability of a Directly Coupled Tandem-Towed Fighter Airplane and Correlation with Experimental Data

NASA Technical Reports Server (NTRS)

Shanks, Robert E.

1958-01-01

A theoretical method is presented for predicting the dynamic lateral stability characteristics of an airplane towed in tandem by a much larger airplane. Values of period and time to damp to one-half amplitude and rolling motions calculated by an analog computer have been correlated with results of two experimental investigations conducted in the Langley free-flight tunnel which were part of a U.S. Air Force program (Project FICON) to develop a satisfactory arrangement by which a bomber could tow a parasite fighter. In general, the theoretical results agree with the experimental results.

Advanced and innovative wind energy concept development: Dynamic inducer system, executive summary

NASA Astrophysics Data System (ADS)

Lissaman, P. B. S.; Zalay, A. D.; Hibbs, B. H.

1981-05-01

Concepts to improve the technical and economic performance of wind energy conversion systems (WECS) were examined. One technique for improving the cost-effectiveness of WECS is the use of tip vanes. Tip vanes are small airfoils attached approximately at right angles to the rotor tips with their span oriented approximately parallel to the local freestream. The performance benefits of the dynamic inducer tip vane system were demonstrated Tow-tests conducted on a three-bladed, 3.6-meter diameter rotor show that a dynamic inducer can achieve a power coefficient of 0.5, which exceeds that of a plain rotor by about 35%.

Advanced and innovative wind energy concept development: Dynamic inducer system

NASA Astrophysics Data System (ADS)

Lissaman, P. B. S.; Zalay, A. D.; Hibbs, B. H.

1981-05-01

The performance benefits of the dynamic inducer tip vane system was demonstrated Tow-tests conducted on a three-bladed, 3.6-meter diameter rotor show that a dynamic inducer can achieve a power coefficient (based pon power blade swept area) of 0.5, which exceeds that of a plain rotor by about 35%. Wind tunnel tests conducted on a one-third scale model of the dynamic inducer achieved a power coefficient of 0.62 which exceeded that of a plain rotor by about 70%. The dynamic inducer substantially improves the performance of conventional rotors and indications are that higher power coefficients can be achieved through additional aerodynamic optimization.

46 CFR 15.410 - Credentialed individuals for assistance towing vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Credentialed individuals for assistance towing vessels. 15.410 Section 15.410 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; All Vessels § 15.410 Credentialed individuals...

Pilot evaluation of the use of contract towing and first responder strategies in the Virginia Department of Transportation's Staunton District.

DOT National Transportation Integrated Search

2017-06-01

This study evaluated the contract towing and first responder pilot projects in the Virginia Department of Transportations : Staunton District. The evaluation included before and after studies of incident duration and comparisons of clearance time....

46 CFR 15.410 - Credentialed individuals for assistance towing vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Credentialed individuals for assistance towing vessels. 15.410 Section 15.410 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; All Vessels § 15.410 Credentialed individuals...

46 CFR 15.410 - Credentialed individuals for assistance towing vessels.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Credentialed individuals for assistance towing vessels. 15.410 Section 15.410 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; All Vessels § 15.410 Credentialed individuals...

46 CFR 15.410 - Credentialed individuals for assistance towing vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Credentialed individuals for assistance towing vessels. 15.410 Section 15.410 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; All Vessels § 15.410 Credentialed individuals...

46 CFR 15.410 - Credentialed individuals for assistance towing vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Credentialed individuals for assistance towing vessels. 15.410 Section 15.410 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; All Vessels § 15.410 Credentialed individuals...

Lake Michigan Green Bay: Nearshore Variability

EPA Science Inventory

We conducted a high-resolution survey in the nearshore of Lake Michigan’s Green Bay at a 15 meter contour using towed electronic instrumentation. The 365 km survey was conducted Aug 18-21, 2010. We also conducted four cross-contour tows. Along the survey tracks we sampled fixe...

22. Photocopy of photograph (original in the Langley Research Center ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

22. Photocopy of photograph (original in the Langley Research Center Archives, Hampton, VA LaRC) (L6415) STUFFED SEAGULL ON CARRIAGE OF TOWING TANK - 1932; EXPERIMENT TO DETERMINE AERODYNAMIC QUALITIES OF BIRDS. - NASA Langley Research Center, Seaplane Towing Channel, 108 Andrews Street, Hampton, Hampton, VA

33 CFR 155.235 - Emergency towing capability for oil tankers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Emergency towing capability for oil tankers. 155.235 Section 155.235 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR...

33 CFR 155.235 - Emergency towing capability for oil tankers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Emergency towing capability for oil tankers. 155.235 Section 155.235 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR...

33 CFR 155.235 - Emergency towing capability for oil tankers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Emergency towing capability for oil tankers. 155.235 Section 155.235 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR...

Processing effects in production of composite prepreg by hot melt impregnation

NASA Astrophysics Data System (ADS)

Chmielewski, C.; Jayaraman, K.; Petty, C. A.

1993-06-01

The hot melt impregnation process for producing composite prepreg has been studied. The role of the exit die is highlighted by operating without impregnation bars. Experimental results show that when a fiber tow is pulled through a resin bath and then through a wedge shaped die, the total resin mass fraction and the extent of resin impregnation in the tow increase with the processing viscosity. The penetration of resin into a fiber bundle is greater when the resin viscosity is higher. This trend is unchanged over a range of tow speeds up to the breaking point. A theoretical model is developed to describe the effect of processing conditions and die geometry on the degree of impregnation. Calculations with this model indicate that for a given die geometry, the degree of impregnation increases from 58 percent to 90 percent as the ratio of the clearance between the tow and the die wall, to the total die gap is decreased from 0.15 to 0.05. Physical arguments related to the effective viscosity of the prepreg show that the clearance ratio is independent of the tow speed, but decreases as the ratio of the effective shear viscosity of the prepreg to the resin viscosity increases. This provides a connection between the experimental results obtained with varying resin viscosity and the computational results obtained with varying clearance values at the die inlet.

KSC-08pd3887

NASA Image and Video Library

2008-11-30

EDWARDS, Calif. – Against a setting sun, space shuttle Endeavour undergoes recovery operations on Edwards Air Force Base in California after its landing. The orbiter convoy normally begins recovery operations in earnest about two hours before the shuttle is scheduled to land. Specially designed vehicles or units and a team of trained personnel “safe” the orbiter and prepare it for towing. Purge and Coolant Umbilical Access Vehicles are moved into position behind the orbiter to get access to the umbilical areas. The flight crew is replaced aboard the orbiter by exchange sup¬port personnel who prepare the orbiter for ground tow operations, install switch guards and remove data packages from any onboard experiments. After a total safety downgrade, vehicle ground personnel make numerous preparations for the towing operation, including install¬ing landing gear lock pins, disconnecting the nose landing gear drag link, positioning the towing vehicle in front of the orbiter and connecting the tow bar. The decision to land Endeavour at Edwards was made due to weather concerns at NASA's Kennedy Space Center in Florida. In the 52nd landing at Edwards, Endeavour touched down at 4:25 p.m. EST to end the STS-126 mission, completing its 16-day journey of more than 6.6 million miles in space. Endeavour will be returned to Kennedy atop a Shuttle Carrier Aircraft, or SCA, a modified Boeing 747 jetliner. Photo credit: NASA/Tony Landis, VAFB

KSC-08pd3888

NASA Image and Video Library

2008-11-30

EDWARDS, Calif. – Against a setting sun, space shuttle Endeavour undergoes recovery operations on Edwards Air Force Base in California after its landing. The orbiter convoy normally begins recovery operations in earnest about two hours before the shuttle is scheduled to land. Specially designed vehicles or units and a team of trained personnel “safe” the orbiter and prepare it for towing. Purge and Coolant Umbilical Access Vehicles are moved into position behind the orbiter to get access to the umbilical areas. The flight crew is replaced aboard the orbiter by exchange sup¬port personnel who prepare the orbiter for ground tow operations, install switch guards and remove data packages from any onboard experiments. After a total safety downgrade, vehicle ground personnel make numerous preparations for the towing operation, including install¬ing landing gear lock pins, disconnecting the nose landing gear drag link, positioning the towing vehicle in front of the orbiter and connecting the tow bar. The decision to land Endeavour at Edwards was made due to weather concerns at NASA's Kennedy Space Center in Florida. In the 52nd landing at Edwards, Endeavour touched down at 4:25 p.m. EST to end the STS-126 mission, completing its 16-day journey of more than 6.6 million miles in space. Endeavour will be returned to Kennedy atop a Shuttle Carrier Aircraft, or SCA, a modified Boeing 747 jetliner. Photo credit: NASA/Tony Landis, VAFB

KSC-08pd3885

NASA Image and Video Library

2008-11-30

EDWARDS, Calif. – On Edwards Air Force Base in California, space shuttle Endeavour undergoes recovery operations after its landing. The orbiter convoy normally begins recovery operations in earnest about two hours before the shuttle is scheduled to land. Specially designed vehicles or units and a team of trained personnel “safe” the orbiter and prepare it for towing. Purge and Coolant Umbilical Access Vehicles are moved into position behind the orbiter to get access to the umbilical areas. The flight crew is replaced aboard the orbiter by exchange sup¬port personnel who prepare the orbiter for ground tow operations, install switch guards and remove data packages from any onboard experiments. After a total safety downgrade, vehicle ground personnel make numerous preparations for the towing operation, including install¬ing landing gear lock pins, disconnecting the nose landing gear drag link, positioning the towing vehicle in front of the orbiter and connecting the tow bar. The decision to land Endeavour at Edwards was made due to weather concerns at NASA's Kennedy Space Center in Florida. In the 52nd landing at Edwards, Endeavour touched down at 4:25 p.m. EST to end the STS-126 mission, completing its 16-day journey of more than 6.6 million miles in space. Endeavour will be returned to Kennedy atop a Shuttle Carrier Aircraft, or SCA, a modified Boeing 747 jetliner. Photo credit: NASA/Tony Landis, VAFB

KSC-08pd3886

NASA Image and Video Library

2008-11-30

EDWARDS, Calif. – On Edwards Air Force Base in California, space shuttle Endeavour undergoes recovery operations after its landing. The orbiter convoy normally begins recovery operations in earnest about two hours before the shuttle is scheduled to land. Specially designed vehicles or units and a team of trained personnel “safe” the orbiter and prepare it for towing. Purge and Coolant Umbilical Access Vehicles are moved into position behind the orbiter to get access to the umbilical areas. The flight crew is replaced aboard the orbiter by exchange sup¬port personnel who prepare the orbiter for ground tow operations, install switch guards and remove data packages from any onboard experiments. After a total safety downgrade, vehicle ground personnel make numerous preparations for the towing operation, including install¬ing landing gear lock pins, disconnecting the nose landing gear drag link, positioning the towing vehicle in front of the orbiter and connecting the tow bar. The decision to land Endeavour at Edwards was made due to weather concerns at NASA's Kennedy Space Center in Florida. In the 52nd landing at Edwards, Endeavour touched down at 4:25 p.m. EST to end the STS-126 mission, completing its 16-day journey of more than 6.6 million miles in space. Endeavour will be returned to Kennedy atop a Shuttle Carrier Aircraft, or SCA, a modified Boeing 747 jetliner. Photo credit: NASA/Tony Landis, VAFB

The hydrodynamic drag and the mobilisation of sediment into the water column of towed fishing gear components

NASA Astrophysics Data System (ADS)

O'Neill, F. G.; Summerbell, Keith David

2016-12-01

The hydrodynamic drag of towed fishing gears leads to direct impacts on the benthic environment, and can play a major role in the overall economic efficiency of the fishing operation and emissions of nitrogen oxides, sulphur oxides and greenhouse gases such as CO2. Here we investigate some of the underpinning processes which govern these issues and make direct hydrodynamic drag measurements and calculate the hydrodynamic drag coefficients for a range of well-defined gear components that, when fished, are in contact with the seabed. We measure the concentration and particle size distribution of the sediment mobilised into the water column in the wake of these gear elements, at a range of towing speeds, and demonstrate that as the hydrodynamic drag increases the amount of sediment mobilised also increases. We also vary the weight of the elements and show that this does not influence the amount of sediment put into the water column. These results provide a better understanding of the physical and mechanical processes that take place when a towed fishing gear interacts with the seabed. They will permit the development of more fuel efficient gears and gears of reduced benthic impact and will improve the empirical modelling of the sediment mobilised into the turbulent wake behind towed fishing gears which will lead to better assessments of the environmental and ecological impact of fishing gears.

The effect of the Advanced Placement Training and Incentive Program on increasing enrollment and performance on Advanced Placement science exams

NASA Astrophysics Data System (ADS)

Ramsey, Susan Brady

The purpose of this study is to examine the effectiveness of the National Math and Science Initiative's Advanced Placement Training and Incentive Program (APTIP) on the number of students taking AP science courses and their performance. The study evaluated 39 schools over a six-year period in six states that participate in the APTIP. The National Math and Science Initiative provided data for cohort I. A general linear model for repeated measures was used to evaluate the data. Data was evaluated three years prior to the intervention and three years during the intervention, which will actually continue for two more years (2012 and 2013) since cohort I schools were awarded five years of support. Students in APTIP schools enrolled in more AP science exams (AP Biology, AP Chemistry, AP Environmental Science, and AP Physics-B) over the course of the intervention. The quantity of students earning qualifying scores increased during the intervention years. APTIP is a multi-tiered program that includes seven days of teacher training, three six-hour student prep sessions, school equipment, reduced exam fees, and monetary incentives for students and teachers. This program positively impacted the quantity of enrollment and qualifying scores during the three years evaluated in this study. Increases in the number of female and African American students' test takers their and qualifying scores were seen in all three years of the APTIP intervention. This study supports the premise that the first step to increasing the Science, technology, engineering, and math (STEM) pipeline is giving access to advanced courses to more students in high schools.

33 CFR 164.78 - Navigation under way: Towing vessels.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Navigation under way: Towing vessels. 164.78 Section 164.78 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY NAVIGATION SAFETY REGULATIONS § 164.78 Navigation under way...

33 CFR 164.78 - Navigation under way: Towing vessels.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Navigation under way: Towing vessels. 164.78 Section 164.78 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY NAVIGATION SAFETY REGULATIONS § 164.78 Navigation under way...

33 CFR 164.78 - Navigation under way: Towing vessels.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Navigation under way: Towing vessels. 164.78 Section 164.78 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY NAVIGATION SAFETY REGULATIONS § 164.78 Navigation under way...

Autonomous Refueling of Unmanned Vehicles at Sea

DTIC Science & Technology

2008-03-28

As seen in Figure 3, a floating sponson, similar to the outside flotation collar on a RIB, is towed off the stern of the parent ship with a tow...V. Minnick, Thomas G. Beukema, Wojciech Kauczynski, Andrew L. Silver , and Christopher Cleary, “Stern Boat Deployment Systems and Operability

KSC-04pd1275

NASA Image and Video Library

2004-05-05

KENNEDY SPACE CENTER, FLA. - A tug boat begins towing the barge containing an External Tank (ET) to Port Canaveral. There one of the SRB Retrieval Ships will take over and tow the ET to the Michoud Space Systems Assembly Facility near New Orleans where redesign of the external tank is underway for Return to Flight.